JP2003083782A - Adjustment device for flow rate sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adjustment device for a flow rate sensor that can easily achieve the rotation adjustment work for an impeller without using a dedicated controller. SOLUTION: A water meter 1 comprises a fluid pipe 2, an impeller 3 arranged inside this fluid pipe 2, and a flow straightener 4 arranged at the upper stream side of the impeller 3. The rotation adjustment for the impeller 3 is achieved by relatively rotating the flow straightener 4 to the fluid pipe 2 circumferentially. A fitting projection 441 and a fitting groove 261 are formed on an annular end surface 44 and a circular step surface 26 which are the matching surfaces of the flow straightener 4 and the fluid pipe 2, and thereby a relative circumferential position is defined. A projection 46 formed on the outer circumference surface of the flow straightener 4 is fitted into a circular groove 25 formed on the internal circumference surface of the fluid pipe 2, and thereby the flow straightener 4 is fixed at a rotation position after adjustment in the fluid pipe 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow sensor represented by a water meter. For more details,
The present invention relates to a flow rate sensor having a rotation adjusting member arranged inside a fluid pipe adjacent to an impeller for adjusting a rotational state of an impeller for flow rate measurement arranged in the fluid pipe.

[0002]

2. Description of the Related Art As a flow rate sensor such as a water meter,
There is known a configuration in which an impeller that rotates according to a flow rate is provided inside a fluid pipe, the rotation of the impeller is detected by a magnetic sensor, and the flow rate is measured based on the detection output.

In this type of flow rate sensor, adjustment for rotating the impeller at a predetermined number of revolutions according to the flow rate is performed by a rectifier, a resistance plate, etc. mounted inside the fluid pipe on the upstream side of the impeller. This is done by adding a dedicated component called a regulator. Instead of this, the rotation of the impeller may be adjusted by adjusting the mounting positions of the rectifier and the resistance plate in the fluid pipe.

[0004]

However, in a flow rate sensor such as a water meter equipped with an impeller as described above,
Skilledness is required to adjust the rotation of the impeller using the adjuster, and the cost of the flow sensor is increased because the adjuster is required.

Further, in the method of adjusting the positions of the rectifier and the resistance plate, it is necessary to loosen or tighten the screws or the like that fix the rectifier and the resistance plate to the fluid pipe each time the adjustment is made.
Adjustment takes time.

Therefore, an object of the present invention is to propose an adjusting device for a flow sensor which can easily perform the rotation adjusting work of the impeller without using a special adjusting device.

[0007]

In order to solve the above-mentioned problems, the present invention relates to the above-mentioned fluid adjacent to an impeller for adjusting the rotational state of an impeller for flow rate measurement arranged in a fluid pipe. In a flow sensor adjusting device having a rotation adjusting member arranged at a position inside a pipe, the rotation adjusting member is arranged at a downstream side part of the impeller and at a part upstream of the impeller. A rectifier, at least one of the rectifier plate and the rectifier is a position-adjustable rectifying component mounted in a state in which the relative mounting position can be changed in the circumferential direction with respect to the fluid pipe, Between the rectifying component and the fluid pipe, a positioning portion for defining the relative position of the rectifying component in the circumferential direction with respect to the fluid pipe, and the rectifying component on the fluid pipe at the positioned position. It is characterized in that the holding portion for holding detachably are formed.

Here, the positioning portion may be a plurality of radially extending grooves or protrusions formed on the mating surfaces of the rectifying component and the fluid pipe.

The holding portion includes an annular groove formed on the inner peripheral surface of the fluid pipe, and a protrusion capable of being fitted into the annular groove formed on the outer peripheral surface of the rectifying component. The protrusion may be elastically displaceable in the central direction of the fluid pipe.

In the present invention, when the mounting position of at least one of the rectifier and the rectifying plate is finely adjusted in the circumferential direction of the fluid pipe, the relative mounting positions in these circumferential directions change. As a result, the flow direction of the fluid flowing through them changes, so that the rotation state of the impeller can be adjusted to the target rotation state. Therefore, it is possible to perform the rotation adjustment without adding an adjusting device for the rotation adjustment as in the conventional case, so that it is possible to suppress the cost increase of the flow rate sensor.

Further, between the positionally adjustable rectifier or rectifying plate and the fluid pipe, there is provided a positioning portion for defining a relative position in the circumferential direction, and a position positioned with respect to the fluid pipe. Since the holding portion that holds the rectifier or the rectifying plate is formed, the position where the rectifier is attached to the fluid pipe can be easily adjusted.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a water meter to which the present invention is applied will be described below with reference to the drawings.

1 (a), (b) and (c) are a sectional view, a left side view and a right side view showing a water meter to which the present invention is applied. As shown in this figure, the water meter 1
Has a fluid pipe 2, an axial flow type impeller 3 arranged coaxially inside the fluid pipe 2, and a rectifier 4 arranged inside the fluid pipe 2 on the upstream side of the impeller 3. is doing.

The fluid pipe 2 has an upstream opening 21 to which an upstream water pipe is connected, a downstream opening 22 to which a downstream water pipe is connected, and a small diameter formed in a portion adjacent to the upstream opening 21. The rectifier arrangement portion 23 and the impeller arrangement portion 24 having a smaller diameter formed on the downstream side of the rectifier arrangement portion 23.

The upstream side opening 2 in the rectifier arrangement portion 23
An annular groove 25 is formed on the inner peripheral surface on the first side. An annular step surface 26 is provided between the rectifier arrangement portion 23 and the impeller arrangement portion 24. A bearing portion 27 that supports the downstream end of the impeller 3 is formed on the inner surface of the impeller arrangement portion 24 downstream of the annular step surface 26 on the downstream opening 21 side.

The bearing portion 27 includes an impeller arrangement portion 24.
The inner peripheral surfaces of the blades are vertically connected, and straightening vanes 28 that horizontally protrude from both sides in the vertical direction extend to the inner peripheral surface of the impeller arrangement portion 24.

The impeller 3 has a downstream end rotatably supported by a bearing 27, and an upstream end rotatably supported by a downstream end surface of a rectifier 4 attached to the fluid pipe 2. A magnet 51 is embedded in the downstream end surface of the impeller 3. A magnetic sensor 52 is arranged inside the bearing portion 27 of the fluid pipe 2 so as to face the magnet 51. A cable 53 from the magnetic sensor 52 is connected to the measuring unit side (not shown). When the impeller 3 rotates, a rotating magnetic field is generated by the magnet 51, and the magnetic change of the magnetic field causes the magnetic sensor 52 to rotate.
Is detected as an electric signal by the detector, the detected signal is processed on the side of the measuring unit, and the flow rate is measured.

Next, FIG. 2 is a perspective view showing the rectifier 4. Referring to FIGS. 1 and 2, the rectifier 4 includes a bearing 41 that rotatably supports one end of an impeller,
The rectifier arrangement portion 2 of the fluid pipe is provided upstream of the bearing portion 41.
3 has a tubular portion 42 fitted therein, and eight plate-shaped blades 43 radially formed inside the tubular portion 42 and attached to the bearing portion 41. The rectifier 4 is mounted at a position where the downstream annular end surface 44 of the tubular portion 42 abuts on the annular step surface 26 of the fluid pipe 2 and is rotatable in the circumferential direction of the fluid pipe 2. By rotating the rectifier 4 in the circumferential direction of the fluid pipe 2, the relative position of the blade 43 with respect to the rectification plate 28 on the fluid pipe 2 side is changed, so that the water flow passing therethrough is changed to change the rotation characteristics of the impeller 3. Can be adjusted. Thus, the blades 43 of the rectifier 4 and the rectifying plate 28 of the fluid pipe 2
Functions as a rotation adjusting member of the impeller 3.

Here, the tubular portion 42 is formed with four arm portions 45 which are elastically displaceable in the central direction of the fluid pipe 2 by making a cut from the upstream end surface to the outer peripheral surface. A protrusion 46 is formed on the upstream end of each of the arm portions 45 toward the outside, and a claw portion 47 is formed on the upstream side of the protrusion 46.

FIG. 3 is a sectional view showing a portion cut along the line AA of FIG. 1, and as shown in this figure, the arm portion 4
The protrusion 46 of 5 fits in the annular groove 25 of the rectifier arrangement portion 23 of the fluid pipe 2, and holds the rectifier 4 in the fluid pipe 2. In addition, the projection 46 connects the claw portion 47 to the fluid pipe 2
It can be removed from the annular groove 25 by pressing it toward the center of the arm and moving the arm 45. Therefore, the rectifier 4 can be attached to and detached from the fluid pipe 2 by pressing the claw portion 47 toward the center of the fluid pipe 2.

Next, a positioning portion for defining the relative position in the circumferential direction is formed on the mating surface between the tubular portion 42 and the impeller arrangement portion 24 of the fluid pipe 2. FIG. 4 is a view showing this positioning portion, and is an enlarged perspective view showing a portion B surrounded by a circle in FIG. As shown in this figure, radial fitting projections 441 formed at a constant angle are formed on the annular end surface 44 of the tubular portion 42 on the rectifier 4 side, and the annular step surface 26 on the fluid pipe 2 side is formed. Also, radial fitting grooves 261 are formed at the same angle. By changing the position where the fitting protrusion 441 fits in the fitting groove 261, the relative position of the rectifier 4 with respect to the fluid pipe 2 can be defined.

In the water meter 1 thus constructed, when adjusting the rotation of the impeller 3, the arm portion 45 of the rectifier 4 is pressed toward the center of the fluid pipe 2 so that the projection 46 circles the fluid pipe 2. The rectifier 4 may be removed from the annular groove 25, and then the rectifier 4 may be rotated to a position where desired rotation characteristics are obtained. The position of the rectifier 4 is determined by a plurality of radially extending fitting protrusions 441 and fitting grooves 2 formed on the mating surfaces of the rectifier 4 and the fluid pipe 2.
It is defined stepwise by fitting 61 together. If the pressing of the arm portion 45 of the rectifier 4 is released at the adjusted position, the protrusion 46 fits into the annular groove 25, and the rectifier 4 can be fixed to the fluid pipe 2 at that position. Therefore, when adjusting the rotation of the impeller 3, it is not necessary to add an adjustment device for rotation adjustment as in the conventional case, and the rotation adjustment of the rectifier 4 with respect to the fluid pipe 2 is
Loosen screws to position and fix the rectifier 4,
It can be easily done without tightening.

Although the above example relates to a water meter, it goes without saying that the present invention can be similarly applied to a flow sensor other than the water meter.

Further, in the above example, the flow straightening plate 28 located at the downstream side portion of the impeller 3 is fixed to the fluid pipe 2, but this flow straightening plate 28, like the flow straightener 4, is also a fluid. The pipe 2 may be attached in such a manner that its relative position in the circumferential direction can be adjusted. Alternatively, instead of the rectifier 4, the rectifying plate 2
Only 8 may be attached to the fluid pipe 2 with the relative attachment position in the circumferential direction being adjustable.

[0025]

As described above, in the flow sensor of the present invention, the rectifier and / or the rectifying plate are moved relatively minutely in the circumferential direction of the fluid pipe so that the rectifier and / or the rectifying plate can move relative to the fluid pipe. By finely adjusting the mounting position, the rotation of the impeller is adjusted.

Therefore, it is not necessary to add an adjusting device for rotation adjustment as in the prior art, and the cost increase of the flow rate sensor can be suppressed.

Further, in the present invention, a positioning portion for defining a relative position in the circumferential direction between the rectifier and / or the rectifying plate and the fluid pipe, and a position where the rectifier and / or the rectifying plate are positioned. In the above, a holding portion that detachably holds the fluid pipe is formed. Therefore, the rectifier and / or
Alternatively, the work of rotating the rectifying plate relative to the fluid pipe to position and fix the rectifying plate can be easily performed without using a fixing fitting such as a screw.

[Brief description of drawings]

FIG. 1 (a), (b) and (c) are a cross-sectional view, a left side view and a right side view showing a water meter to which the present invention is applied.

FIG. 2 is a perspective view showing a rectifier of the water meter shown in FIG.

3 is a cross-sectional view showing a portion cut along line AA in FIG.

FIG. 4 is an enlarged perspective view showing a connecting portion B between the tubular portion and the fluid pipe in FIG.

[Explanation of symbols]

1 water meter 2 fluid pipe 3 impeller 4 rectifier 21 upstream opening 22 Downstream opening 23 Rectifier arrangement part 24 Impeller placement part 25 circular groove 26 annular step 27 Bearing section 28 Current plate 41 Bearing 42 Tube 43 feathers 44 annular end face 441 Mating protrusion 261 Mating groove 45 arms 46 protrusions

Claims (3)

[Claims] 1. An adjusting device for a flow rate sensor, comprising a rotation adjusting member arranged at a portion in the fluid pipe adjacent to the impeller for adjusting a rotational state of an impeller for measuring a flow rate arranged in the fluid pipe. The rotation adjusting member includes a rectifying plate arranged at a site on the downstream side of the impeller and a rectifier arranged at a site on the upstream side of the impeller, and at least one of the rectifying plate and the rectifier is A position-adjustable rectifying component that is mounted in a state in which a relative mounting position can be changed in a circumferential direction with respect to the fluid pipe, and the fluid of the rectifying component is provided between the rectifying component and the fluid pipe. A positioning part for defining a relative position in the circumferential direction with respect to the pipe, and a holding part detachably holding the rectifying component on the fluid pipe at the positioned position. Adjusting device for flow sensor. 2. The flow sensor adjustment device according to claim 1, wherein the positioning portion is a plurality of radially extending grooves or protrusions formed on a mating surface of the rectifying component and the fluid pipe. 3. The holding portion according to claim 1, wherein the holding portion can be fitted into an annular groove formed on an inner peripheral surface of the fluid pipe and the annular groove formed on an outer peripheral surface of the rectifying component. A protrusion, and the protrusion is elastically displaceable in the central direction of the fluid pipe.