JPH11304551A - Water meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the complete prevention of water leakage by providing a lip seal for the inflow opening part of an inner case and pressing the tip part of the lip seal against the inner peripheral surface to be fitted of the inner case i.e., the outer periphery of an inlet. SOLUTION: The inflow opening part of an inner case 5 is formed in a square shape larger than the inner diameter of an inlet 3, and a groove 14 for installing a lip seal 13 is endlessly formed at all the inner surfaces of the inflow opening part of the inner case 5. The main body of the lip seal 13 is squarely formed so as to be fitted into the installing groove 14, and a tip-shaped sealing part 13b with a tapered cross section is circularly formed at the center part. The sealing part 13b is formed approximately in a truncated conical shape with a large-diameter inner-end side and a small-diameter tip part, and its inner surfaces are formed in a circular surface. With the sealing part 13b directed outward, the lip seal 13 is easily installed to the inner case 5 dividing a bottom wall 5b by fitting the installing end part at the outer periphery into the installing groove 14. By this, it is possible to reduce water leakage and improve the performance of a water meter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a water meter.

[0002]

2. Description of the Related Art In a conventional water meter, a measuring chamber 103 is provided between an inlet 101 and an outlet 102 as shown in FIG.
In some cases, the impeller 104 is rotated by tap water flowing through the measuring chamber 103, and the pointer 107 is rotated by the gear train in the indicating section 106 by the rotation of the impeller shaft 105.

[0003] In such a water meter, an inner case 109 is fitted into an outer case 108 having the above-mentioned inlet 101 and outlet 102 as shown in FIG. In some cases, water leakage from the gap is prevented by increasing the processing accuracy of the fitting inner peripheral surface of the outer case 108 and the fitting outer peripheral surface of the inner case 109. In the drawing, reference numeral 110 denotes a strainer made of a hard material, which has no sealing action.

[0004]

As described above, the processing accuracy between the inner peripheral surface of the outer case 108 and the outer peripheral surface of the inner case 109 is improved, and the gap between them is made as small as possible to prevent water leakage. In the case of prevention, there is a limit in the processing accuracy, and it is impossible to completely prevent water leakage. Therefore, the water leaking from the gap is not measured, and there is a problem that an error is caused by the amount of the water leak and the instrumental performance of the water meter is reduced.

[0005] Further, between the two cases 108 and 109, O
It is conceivable to completely prevent water leakage by installing a ring. However, if the O-ring has a large frictional resistance such as rubber, its slippage is poor and it is difficult to mount the case. Then, it is difficult to assemble and assemble.

Therefore, an object of the present invention is to provide a water meter that solves the above-mentioned problems.

[0007]

According to a first aspect of the present invention, an inner case is fitted in an outer case, and the inner case is fitted to an inlet of the outer case. A lip seal is provided at the inflow opening of the inner case, and a tip of the lip seal is attached to the inner case of the outer case. Is pressed into contact with the outer peripheral surface of the inflow port.

According to the present invention, the tip of the lip seal is pressed against the inner peripheral surface of the outer case, thereby preventing water from leaking into the gap between the inner peripheral surface of the outer case and the inner peripheral surface of the inner case. . Furthermore, the former produces a higher differential pressure between the inner water pressure and the outer water pressure of the seal portion of the lip seal, so that the seal portion comes into pressure contact with the inner peripheral surface of the outer case, thereby improving the sealing effect. In particular, when the flow rate of water is large, the above differential pressure becomes large.

According to a second aspect of the present invention, in the first aspect, a strainer is integrally formed with the lip seal. According to the present invention,
In addition to exerting the function of the above-mentioned lip seal, the lip seal portion and the strainer become one part.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on a preferred embodiment shown in FIGS.

FIGS. 1 to 4 show a first embodiment. Book first
In the embodiment, a cylindrical inner case storage chamber 2 is formed in an outer case 1 constituting a water meter, and an inflow port 3 and an outflow port 4 are formed at opposed positions 180 ° apart in a circumferential direction. Both ports 3 and 4 are open to the inner case storage chamber 2.

A cylindrical inner case 5 is fitted into the inner case storage chamber 2. The inner case 5 includes a cylindrical peripheral wall 5a fitted to the inner peripheral surface of the storage chamber 2 and a bottom wall 5b mounted on the inner bottom surface of the outer case 1.
And an intermediate wall 5c located above the ports 3 and 4, forming a passage space between the bottom wall 5b and the intermediate wall 5c. In addition, the bottom wall 5b is formed separately from the peripheral wall 5a and the intermediate wall 5c from the viewpoint of molding.

An inflow opening 5e and an outflow opening 5f are formed in the peripheral wall 5a at the inlet 3 and the outlet 4, respectively. The water flowing from the inlet 3 rotates the impeller 6 through a passage formed between the bottom wall 5b and the intermediate wall 5c, and flows out from the outlet 4. The structure of the passage is the same as the structure proposed by the present applicant in Japanese Utility Model Laid-Open No. 2-10409, and the description thereof is omitted.

The rotation of the rotary shaft 7 of the impeller 6 is transmitted to a gear train (not shown) provided in the indicating section 8 to rotate the hands P and to display the flow rate by the hands P. I have.

An upper case 9 is screwed on the upper part of the outer case 1 and a window glass 10 is pressed by the upper case 9.
The airtightness of the window glass 10 is ensured by the packing 11. A strainer 12 is provided at the inflow end of the inflow port 3.
Is provided.

A lip seal 13 is provided in the inflow opening 5e of the inner case 5. The lip seal 13 and its mounting structure will be described in detail. The inflow opening 5e of the inner case 5 is formed in a square shape larger than the inner diameter of the inflow port 3, and the lip seal 1
The third mounting groove 14 is formed endlessly.

The lip seal 13 is formed of a soft elastic material such as soft resin or rubber, and as shown in FIG. 3, the outer shape of the main body 13a is formed in a square shape which can be fitted in the mounting groove 14. . Further, a lip-shaped seal portion 13b having a tapered cross section is formed in an annular shape at the center thereof. Further, the seal portion 13b is formed in a substantially frusto-conical shape with a large diameter on the inner end 13c side and a small diameter on the tip end 13d, and an inner surface is formed on an arc surface 13e centered on the inside.
Further, a flow passage 13f is formed in the seal portion 13b. Further, the inner diameter of the distal end 13d of the seal portion 13b is set to be substantially the same as or slightly larger than the inner diameter of the inflow port 3 when the distal end 13d is mounted as shown in FIG.

Further, the main body 13a of the lip seal 13
3D, the planar shape of the seal portion 13b is formed in an arc shape as shown in FIG.
Are formed in an arc centered on the rotation axis 7.

Further, the main body 13 of the lip seal 13
The thickness of the mounting end portion a, that is, the upper and lower end portions 13g and 13h and the left and right end portions 13i and 13j is set so as to fit, preferably press-fit, into the mounting groove 14.

As described above, when assembling, first, the lip seal 13 is attached to the inner case 5, the seal portion 13b is directed outward, and the outer peripheral mounting ends 13g to 13g.
13j is fitted into the mounting groove 14 and mounted. At this time,
Since the bottom wall 5b is divided, the inner case 5 can be fitted so as to sandwich the lip seal 13 from above and below,
It can be easily assembled. In addition to mounting the lip seal 13, the impeller and the
Assemble to.

In the assembled state of the lip seal 13,
The tip 13d of the lip seal 13 projects slightly outward from the outer peripheral surface 5g of the inner case 5, as shown in the upper part of FIG.

Then, the inner case 5 is inserted and fitted into the outer case 1 in the above assembled state. At this time, the seal portion 13b of the lip seal 13 is pressed inward and escapes as shown in the lower part of FIG. 4, so that the inner case 5 and the lip seal 13 can be easily fitted.

When the inner case 5 is fitted and stored in a fixed position as shown in FIGS. 1 and 2, the sealing portion 13b of the lip seal 13 is pressed against the inner peripheral surface of the outer case 1 by its restoring force, and The gap between the inner peripheral surface of the case 1 and the outer peripheral surface of the inner case 5 is sealed, and water leakage from the gap is prevented.

When the water flows in the direction of the arrow in FIG. 1, the water pressure inside the seal portion 13b (on the side of the arc surface 13e) and the outside portion A of the seal portion 13b communicating with the downstream side.
Since the former is higher than the latter, the seal 13 b is pressed against the inner peripheral surface of the outer case 1 by the differential pressure. Therefore, the sealing effect is improved by the sealing portion 13b. Since this pressure difference increases especially when the flow rate of water is large,
The sealing effect is further improved when the flow rate of water is large.

FIG. 9 shows an instrumental performance curve between the conventional water meter and the water meter of the present invention.
The dashed line B indicates the curve of the conventional water meter, and the solid line C indicates the curve of the water meter of the present invention. As can be seen from FIG. 9, in the case where the lip seal 13 of the present invention is provided, the water leakage is small and the instrumental performance is improved, and especially in a large flow rate region, the instrumental performance is further improved.

FIGS. 5 to 7 show a second embodiment. Book second
In this embodiment, the strainer 20 is integrally formed with the lip seal 13 of the first embodiment. That is, a lip seal 13 having the same shape as the lip seal 13 of the first embodiment and a plate-like strainer 20 having flow holes 20a located on both sides on the rear surface thereof are integrally formed of a soft elastic material such as soft resin or rubber. It was done. The lip seal 13 is fitted in the mounting groove 14 of the inner case 5 in the same manner as in the first embodiment.

Since the other structure is the same as that of the first embodiment, the same portions are denoted by the same reference numerals and the description thereof will be omitted. In the second embodiment as well, the lip seal 13 exhibits the same function and effect as described above. However, as in the second embodiment, the lip seal 13 and the strainer 20 are integrally formed to form the lip seal 13. Compared to a case in which the lip seal 13 and the strainer 12 are manufactured as separate parts as in the first embodiment, the lip seal 13 and the strainer 12 can be manufactured easily and inexpensively as one part, and can be assembled at one time to facilitate the assembling work. .

[0028]

As described above, according to the first aspect of the present invention, water leakage from the gap between the outer case and the inner case is extremely reduced by the lip seal, and the instrumental performance of the water meter can be improved. Further, it is particularly effective for a water meter having a large flow rate. Further, the work of fitting the inner case provided with the lip seal to the outer case is easy.

According to the second aspect of the present invention, the lip seal and the strainer are made into one piece, so that the manufacturing thereof is easy and inexpensive, and the assembling work is also easy.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a water meter according to a first embodiment of the present invention.

FIG. 2 is a sectional plan view taken along the line DD of FIG. 1;

3A and 3B show the lip seal of FIG. 1, wherein FIG. 3A is an external view, FIG. 3B is a plan view, FIG. 3C is a right side view, and FIG. 3D is a sectional view taken along line EE of FIG. (E) is an enlarged sectional view of the lip-shaped seal portion.

FIG. 4 is a partial cross-sectional view showing a state when the lip seal of FIG. 1 is fitted to an outer case.

FIG. 5 is a longitudinal sectional view of a water meter according to a second embodiment of the present invention.

FIG. 6 is a sectional view taken along line FF in FIG. 5;

7A and 7B show the strainer-integrated lip seal in FIG. 5, wherein FIG. 7A is an external view, FIG. 7B is a plan view, and FIG.
Is a right side view, (d) is a sectional view taken along line GG of (a), (e)
3 is a partial cross-sectional view of a lip-shaped seal portion.

FIG. 8 is a longitudinal sectional view of a conventional water meter.

FIG. 9 is a characteristic diagram showing an instrument difference performance curve between the water meter of the present invention and a conventional water meter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Outer case 3 ... Inflow port 4 ... Outflow port 5 ... Inner case 5e ... Inflow opening 13 ... Lip seal 13b ... Lip-shaped seal part 13d ... Tip part 20 ... Strainer

Claims (2)

[Claims] 1. An inner case is fitted into an outer case,
The inner case is provided with an inflow opening positioned at the inflow port of the outer case and an outflow opening positioned at the outflow port. The inflow opening of the inner case is provided with a lip seal, and the lip seal is provided. The water meter according to claim 1, wherein a front end portion of the outer case is pressed against an inner peripheral surface of the outer case where the inner case is fitted, and an outer periphery of the inlet. 2. The water meter according to claim 1, wherein a strainer is integrally formed with the lip seal.