JP4056313B2 - Double box type weighing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-chamber type metering equipment for measuring the flow rate through the metering fluid.
[0002]
[Prior art]
In this type of conventional multi-box type metering device, the fluid to be weighed in from the inlet of the outer case flows into the inner case from a plurality of inflow nozzles provided at the lower stage of the inner case and having the same inflow cross-sectional area, The impeller provided inside is rotated. And it flows out of the inner case from a plurality of outflow nozzles provided at the upper stage of the inner case and having the same outflow cross-sectional area, and flows out from the outlet of the outer case.
[0003]
[Problems to be solved by the invention]
However, in such a conventional multi-box metering device, the flow velocity flowing into the inflow nozzle on the outflow side of the outer case is smaller than the flow velocity flowing into the inflow nozzle on the inflow port side of the outer case. Therefore, the amount of inflow per unit time from each inflow nozzle into the inner case varies, the rotation of the impeller becomes unstable, and the impeller rotates eccentrically. There was a problem.
[0004]
Accordingly, an object of the present invention is to provide a double box type weighing device in which an impeller rotates stably.
[0005]
[Means for Solving the Problems]
The invention according to claim 1 is provided with a plurality of inflow nozzles in the lower stage of the inner case, a plurality of outflow nozzles in the upper stage of the inner case, and an impeller rotatably provided in the inner case. The fluid to be measured that flows in from the inflow port is divided in the inner case, flows along the flow path formed between the outer case and the inner case, and flows into the inner case from the inflow nozzle. In the multi-box type weighing device, the cross-sectional area of the inflow nozzle is sequentially increased from the inflow side to the outflow side of the outer case.
[0006]
According to a second aspect of the present invention, in the double box type weighing device according to the first aspect, the smaller the degree of the flow direction of the outflow nozzle facing the outflow side, the larger the cross-sectional area of the outflow nozzle. It is characterized by that.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
<First embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a longitudinal section of a double box type tangential flow impeller type water meter as an example of the double box type metering device according to the present invention.
[0013]
Reference numeral 10 in the figure denotes an outer case. The outer case 10 is provided with an inflow port 11a and an outflow port 11b as the inflow port 11, and a strainer 12 is attached in the inflow port 11a. Further, a horizontal installation support 13 is formed on the bottom surface so as to project in a cross shape.
[0014]
An inner case 14 is accommodated in the outer case 10. The inner case 14 is provided with a plurality of inflow nozzles 41 and outflow nozzles 42, respectively, and a pivot 16 is erected at the center of the inner case 14.
[0015]
In the inner case 14, an impeller 18 having a magnet 17 placed on the shaft 16 is rotatably provided on the pivot 16, and an instruction unit 20 is assembled with a lower gasket 19 interposed therebetween. The impeller 18 is housed in the inner case 14.
[0016]
A glass plate attached to the instruction unit 20 with 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, a pointer 28, a numeral wheel 29, and an O-ring 31. 30 is provided. Then, the magnet 25 is opposed to the magnet 17 of the impeller 18 across the bottom wall of the register box 21 to constitute a magnet coupling M.
[0017]
An upper case 33 is mounted on the instruction unit 20 with the upper gasket 32 interposed therebetween, and is screwed to the outer case 10. A lid 35 is attached to the upper case 33 by a pin 34 so as to be opened and closed freely.
[0018]
Then, tap water as the fluid to be measured flows into the outer case 10 from the inlet 11a while removing the foreign matter with the strainer 12, put into the inner case 14 through the plurality of inflow nozzles 41, and the impeller 18 is rotated. It flows out from the outflow nozzle 42 and flows out of the outer case 10 from the outflow port 11b. The rotation of the impeller 18 is transmitted to the magnet gear 26 through the magnet coupling M, transmitted through the gear train 27, and the pointer 28 is rotated. Displays the accumulated flow rate of tap water that has passed through the water meter.
[0019]
Incidentally, the inner case 14 is shown in detail in FIG. That is, the inner case 14 includes a cylindrical side portion 14A and a disk-shaped bottom portion 14B. A plurality of inflow nozzles 41 are provided below the side portion 14A, and a plurality of outflow nozzles 42 are provided above the side portion 14A.
[0020]
As shown in FIG. 3, the inflow nozzle 41 forms an opening 41a on the inner peripheral surface of the side portion 14A and an opening 41b on the outer peripheral surface. A direction from the center of the opening 41b toward the center of the opening 41a is defined as a flow direction 41c. Further, a surface perpendicular to the flow direction 41c at the side edge 41e of the opening 41a is defined as a cross section 41d of the inflow nozzle 41.
[0021]
Similarly, as shown in FIG. 4, the outflow nozzle 42 forms an opening 42 a on the inner peripheral surface of the side portion 14 </ b> A and an opening 42 b on the outer peripheral surface. A direction from the center of the opening 42a toward the center of the opening 42b is defined as a flow direction 42c. Further, a surface perpendicular to the flow direction 42c at the side edge 42e of the opening 42a is defined as a cross section 42d of the outflow nozzle 42.
[0022]
A flow of tap water in the double box type water meter configured as described above will be described. In FIG. 5, the tap water flowing in from the inlet 11 a is divided into a flow on the bottom surface and a flow on the side surface of the inner case 14. Further, the flow on the side surface is divided into two flows S1 and S2 before the inner case 14. The flow S1 flows along a flow path formed between the outer case 10 and the inner case 14, and part of the flow S1 sequentially flows into the inflow nozzles 41A to 41D.
[0023]
During this time, the flow S1 receives frictional resistance from the inner surface of the outer case 10 and the outer surface of the inner case 14, respectively, and the flow velocity decreases, and the flow rate decreases by sequentially flowing into the inflow nozzles 41A, 41B, 41C, 41D. To do. Accordingly, the cross-sectional area (cross-sectional area) of the inflow nozzles 41B and 41C is 50% larger than the cross-sectional area of the inflow nozzle 41A, and the cross-sectional area of the inflow nozzle 41D is 100% larger than the cross-sectional area of the inflow nozzle 41A. The inflow amounts per unit time of the inflow nozzles 41B, 41C, and 41D can be made comparable to those of the inflow nozzle 41A.
[0024]
That is, the cross-sectional areas of the inflow nozzles 41 </ b> A to 41 </ b> D are sequentially increased from the inflow side to the outflow side of the outer case 10. Here, the inflow side of the outer case 10 refers to the side into which the tap water flows into the outer case 10, that is, the inlet 11 a side, and the outflow side of the outer case 10 refers to the outflow of tap water from the outer case 10. Side, that is, the outlet 11b side.
[0025]
Similarly, the flow S2 receives frictional resistance from the inner surface of the outer case 10 and the outer surface of the inner case 14, respectively, and the flow velocity decreases, and the flow rate is increased by sequentially flowing into the inflow nozzles 41H, 41G, 41F, and 41E. Decrease. Accordingly, by making the cross-sectional area of the inflow nozzles 41F and 41G 50% larger than the cross-sectional area of the inflow nozzle 41H and making the cross-sectional area of the inflow nozzle 41E 100% larger than the cross-sectional area of the inflow nozzle 41H, The amount of inflow per unit time of each of 41F and 41G can be made comparable to that of the inflow nozzle 41H. That is, the cross-sectional areas of the inflow nozzles 41 </ b> E to 41 </ b> H are sequentially increased from the inflow side to the outflow side of the outer case 10. At this time, the cross-sectional areas of the inflow nozzle 41A and the inflow nozzle 41H are the same.
[0026]
Thereby, since each inflow nozzle 41A-41H can flow in substantially the same amount of tap water per unit time, tap water hits the blade | wing of the impeller 18 in the inner case 14 equally, It can be rotated stably.
[0027]
And the tap water which rose while rotating the impeller 18 is sequentially discharged | emitted from the outflow nozzles 42A-42C, as shown in FIG. At this time, the smaller the extent that the flow direction of the outflow nozzles 42A to 42C is directed to the outflow side, the larger the cross-sectional area of the outflow nozzles 42A to 42C. That is, the cross-sectional area of the outflow nozzle 42B is 5% larger than the cross-sectional area of the outflow nozzle 42A, and the cross-sectional area of the outflow nozzle 42C is 10% larger than the cross-sectional area of the outflow nozzle 42A. The amount of outflow per unit time can be set to the same level as that of the outflow nozzle 42A.
[0028]
Thereby, since each outflow nozzle 42A-42C can flow out about the same amount of tap water per unit time, tap water flows out equally from the inside of the inner case 14, and rotates the impeller 18 more stably. be able to.
[0029]
FIG. 7 is a diagram comparing instrumental performance of the double box tangential flow impeller water meter of this example and a conventional double box tangential flow impeller water meter. As is clear from this figure, the double box type tangential flow impeller water meter of this example makes the rotation of the impeller 18 smooth due to the uniform inflow rate, and improves the measurement sensitivity in the minute flow rate region, and Durability improvement can be expected.
[0030]
In this example, the cross-sectional area of the inflow nozzles 41B and 41C is 50% larger than the cross-sectional area of the inflow nozzle 41A, and the cross-sectional area of the inflow nozzle 41D is 100% larger than the cross-sectional area of the inflow nozzle 41A. The cross-sectional area of the inflow nozzles 41B and 41C is 30% to 70% larger than the cross-sectional area of the inflow nozzle 41A, and the cross-sectional area of the inflow nozzle 41D is 80% larger than the cross-sectional area of the inflow nozzle 41A. It may be increased by ~ 120%.
[0031]
On the other hand, the cross-sectional area of the inflow nozzles 41F and 41G is 50% larger than the cross-sectional area of the inflow nozzle 41H, and the cross-sectional area of the inflow nozzle 41E is 100% larger than the cross-sectional area of the inflow nozzle 41H. Instead, the cross-sectional area of the inflow nozzles 41F and 41G is 30% to 70% larger than the cross-sectional area of the inflow nozzle 41H, and the cross-sectional area of the inflow nozzle 41E is 80% to 120% larger than the cross-sectional area of the inflow nozzle 41H. May be.
[0032]
Furthermore, the cross-sectional area of the outflow nozzle 42B is 5% larger than the cross-sectional area of the outflow nozzle 42A, and the cross-sectional area of the outflow nozzle 42C is 10% larger than the cross-sectional area of the outflow nozzle 42A, but this is not restrictive. The cross-sectional area of the outflow nozzle 42B may be 3% to 7% larger than the cross-sectional area of the outflow nozzle 42A, and the cross-sectional area of the outflow nozzle 42C may be 8% to 12% larger than the cross-sectional area of the outflow nozzle 42A.
[0033]
Next, another double box type tangential flow impeller water meter will be described with reference to FIG. The double box type tangential flow impeller type water meter of this example is different from the double box type water meter of the first embodiment only in the configuration of the inner case and the mounting position. The description is omitted.
[0034]
Unlike the above example, the eight inflow nozzles 51A to 51H provided in the inner case 51 of this example and a plurality of outflow nozzles (not shown) all have the same cross-sectional area. The inner case 51 is provided so as to be eccentric in the outer case 10. That is, first, the inner case 51 is eccentric to the inflow side. Next, the flow path formed between the inner peripheral surface of the outer case 10 and the outer peripheral surface of the inner case 51 is a region where the blades of the impeller 18 rotate in the forward direction with respect to the flow of tap water. It is decentered so that it is wide in a narrow area that rotates in the opposite direction.
[0035]
At this time, the distance between the outer case 10 and the inner case 51 is the smallest in A and the largest in F so that the same amount of tap water flows into all the inflow nozzles 52A to 52H. Provide unevenness.
[0036]
That is, the distance between the outer case 10 and the inner case 51 in B is larger than the distance between the outer case 10 and the inner case 51 in A, and the outer case in C is larger than the distance between the outer case 10 and the inner case 51 in B. The distance between the outer case 10 and the inner case 51 is sequentially increased so that the distance between the outer case 10 and the inner case 51 is increased.
[0037]
In E, after the distance is maximized, the distance between the outer case 10 and the inner case 51 in F is made smaller than the distance between the outer case 10 and the inner case 51 in E, and The distance from the case 51 is made smaller than the distance between the outer case 10 and the inner case 51 in F.
[0038]
A flow of tap water in the outer case 10 of the double box type water meter configured as described above will be described.
[0039]
The tap water flowing in from the inflow port 11a is divided into a flow on the bottom surface and a flow on the side surface of the inner case 14. Further, the flow on the side surface is divided into two flows S3 and S4 before the inner case 14. The flow S3 flows along a flow path formed between the outer case 10 and the inner case 14, and a part of them flows sequentially into the inflow nozzles 52A to 52D.
[0040]
During this time, the flow S3 receives frictional resistance from the inner peripheral surface of the outer case 10 and the outer peripheral surface of the inner case 14, respectively, and the flow velocity decreases, and the flow S3 sequentially flows into the inflow nozzles 51A, 51B, 51C, 51D, The flow rate decreases. Therefore, the distance between the outer case 10 and the inner case 51 in B is larger than the distance between the outer case 10 and the inner case 51 in A, and the outer case in C is larger than the distance between the outer case 10 and the inner case 51 in B. The inflow amount per unit time in the inflow nozzles 51B to 51E is increased with the inflow nozzle 51A by sequentially increasing the distance between the outer case 10 and the inner case 51, such as increasing the distance between the outer case 10 and the inner case 51. It can be almost the same.
[0041]
Similarly, the flow S4 receives frictional resistance from the inner surface of the outer case 10 and the outer surface of the inner case 51, respectively, and the flow velocity decreases, and the flow rate decreases by sequentially flowing into the inflow nozzles 51H and 51G. Therefore, the distance between the outer case 10 and the inner case 51 in F is made larger than the distance between the outer case 10 and the inner case 51 in G, and the outer case in E is larger than the distance between the outer case 10 and the inner case 51 in F. The inflow amount per unit time in the inflow nozzles 51F to 51H is increased with the inflow nozzle 51A by sequentially increasing the distance between the outer case 10 and the inner case 51, such as increasing the distance between the outer case 10 and the inner case 51. It can be almost the same.
[0042]
Therefore, by decentering the inner case in the outer case, the inflow amounts in the inflow nozzles 51A to 51H per unit time can be made substantially the same, the impeller 18 can be stably rotated, and the fine flow rate range It is possible to provide a double box type water meter that can improve measurement sensitivity and can be expected to have improved durability.
[0043]
And the tap water which rotated the impeller 18 flows out into the outer case 10 from the outflow nozzle which is not shown in figure, and flows out from an outflow port.
[0044]
Next, another multi-box tangential flow impeller water meter will be described with reference to FIG. The double box type tangential flow impeller type water meter of this example is different from the double box type water meter of the first embodiment only in the configuration of the inner case 61. Is omitted.
[0045]
The cross-sectional areas of the plurality of inflow nozzles 62 provided in the lower stage of the inner case 61 in this example are all the same as in the second embodiment. The cross-sectional areas of the plurality of outflow nozzles 63 provided on the upper stage of the inner case 61 are all the same as in the second embodiment. The inflow nozzle 62 is provided so that the flow direction 62a of the inflow nozzle 62 is upward from the outside of the inner case to the inside, and the flow direction 63a of the outflow nozzle 63 is upward from the inside of the inner case to the outside. An outflow nozzle 63 is provided.
[0046]
The flow of tap water in the inner case 61 of the double box water meter configured as described above will be described.
[0047]
Tap water flowing into the inner case 61 from the outer case (not shown) through the inflow nozzle 62 flows upward from the outer side of the inner case 61 to rotate the impeller 18. Then, it flows further upward, flows out from the inner nozzle 61 to the outer case (not shown) through the outflow nozzle 63 provided to be inclined upward from the inner side to the outer side, and flows out from the outlet port.
[0048]
At this time, since the inflow nozzle 62 is provided so as to be inclined upward from the outside of the inner case 61, the tap water flowing in from the inflow nozzle 62 can easily flow upward while rotating the impeller 18, whereas the outflow nozzle Since 63 is provided upward from the inner side to the outer side of the inner case 61, the tap water flowing upward can be smoothly discharged from the outflow nozzle 63. Therefore, the impeller 18 rotates stably and the measurement sensitivity is improved in the minute flow rate region.
【The invention's effect】
[0049]
Therefore, according to the first aspect of the present invention, since the cross-sectional area of the inflow nozzle is sequentially increased from the inflow side to the outflow side of the outer case, all of the inflow nozzles are measured with the same amount per unit time. It is possible to provide a double box type metering device in which fluid can be introduced and the impeller rotates stably. In addition, since the impeller rotates stably, the measurement sensitivity is improved in the minute flow rate region.
[0050]
According to invention of Claim 2, since the cross-sectional area of an outflow nozzle is enlarged, so that the direction where the flow direction of an outflow nozzle is facing the outflow side is small, it is the same amount per unit time from all the outflow nozzles. It is possible to provide a multi-box type metering device in which the fluid to be weighed can flow out and the impeller rotates more stably.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a double box tangential flow impeller water meter as an example of the present invention.
FIG. 2 is a cutaway perspective view of the inner case.
FIG. 3 is an explanatory diagram of the inflow nozzle.
FIG. 4 is an explanatory diagram of the outflow nozzle.
FIG. 5 is a cross-sectional view in the vicinity of the inflow nozzle.
FIG. 6 is a cross-sectional view in the vicinity of the outflow nozzle.
FIG. 7 is a diagram showing the effect of the double box tangential flow impeller water meter of the present invention.
FIG. 8 is a cross-sectional view of the vicinity of the inflow nozzle of another double box tangential flow impeller water meter.
We are a cross-sectional view of the inner case of another multi-chamber type tangential flow impeller type water meter in [9] is et al.
[Explanation of symbols]
10 Outer case 14, 51, 61 Inner case 16 Pivot 18 Impeller 41, 41A, 41B, 41C, 41D, 41E, 41F, 41G, 41H, 51A, 51B, 51C, 51D, 51E, 51F, 51G, 51H, 62 Inflow nozzle 41c, 42c, 62a, 63a Flow direction 42, 63 Outflow nozzle

Claims (2)

A plurality of inflow nozzles at the lower stage of the inner case, a plurality of outflow nozzles at the upper stage of the inner case, and an impeller rotatably provided in the inner case, the fluid to be measured flowing in from the inlet of the outer case In the multi-box type weighing device , which is divided in the inner case, flows along a flow path formed between the outer case and the inner case, and flows into the inner case from the inflow nozzle .
A multi-box type weighing device, wherein the cross-sectional area of the inflow nozzle is sequentially increased from the inflow side to the outflow side of the outer case.   The multi-box type metering device according to claim 1, wherein the smaller the degree of the flow direction of the outflow nozzle facing the outflow side, the larger the cross-sectional area of the outflow nozzle.

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