JPH0360047B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a flow rate detection device for measuring the flow rate of fluid.

Configuration of Conventional Example and its Problems Conventionally, this type of flow rate detection device is configured as shown in FIGS. 1 and 2. In FIGS. 1 and 2, reference numeral 1 denotes an annular flow path having a circular cross section, and an inflow path 2 and an outflow path 3 are opened at the outer periphery of this flow path. This inflow passage 2 is provided with a nozzle 4 . In addition, a sphere 5 is inserted into the annular flow path 1, transparent windows 6 and 7 are formed, and a light emitting element 8 is formed.
and a light receiving element 9 are provided. In such a configuration, when fluid enters the annular channel 1 from the nozzle 4 of the inflow channel 2, the flow flows from the inflow channel 2 to the outflow channel 3 while circulating in the annular channel 1, and the sphere 5 also flows along with it. It moves around inside the annular flow path 1 in the direction of the solid arrow. Since the rotational speed of the sphere is proportional to the flow rate of the fluid, the rotational speed of the sphere 5 is detected as a pulse signal by the light emitting element 8 and the light receiving element 9, and the flow rate is measured through the control circuit.
The first problem with this conventional example is that the flow resistance is large. Since the annular flow path 1 is formed, the inlet and outlet of the flow path change direction, resulting in bending loss, and the circular flow intersects with the flow from the inflow path 2 near the inflow path, resulting in inflow resistance and loss. arise. Furthermore, if the sphere is configured to have a size close to the cross-sectional area of the annular flow path 1 so as to promote the rotation of the sphere 5, a large flow resistance will occur. Further, if a nozzle 4 is provided in the inflow passage 2 so that the sphere 5 circulates smoothly, the flow passage resistance becomes even greater. There are structural issues, such as the structure of the second sensor tends to be large. As mentioned above, the passage resistance increases, so it is necessary to increase the passage diameter to reduce it.
Since it has the annular flow path 1, a corresponding space is required, and the sensor as a whole becomes larger than the front and rear passages. In addition, the directions of the inflow passage 2 and the outflow passage 3 are limited to some extent, which may cause structural restrictions when incorporating it into equipment as a sensor.
There are problems such as increasing the overall size.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a small and compact flow rate detection device that eliminates such conventional drawbacks and has low flow resistance.

Structure of the Invention In order to achieve this object, the present invention includes a swirling means for axially swirling a fluid to be detected flowing in a flow path, and a rotating body located in the swirling flow and rotating in a plane perpendicular to the flow direction. , an outflow prevention means for keeping this rotating body within the range of the swirling flow, and a rotation detecting means for measuring the number of revolutions of the rotating body, and the rotating means has a flat plate twisted coaxially with respect to the flow direction. In addition, a torsion plate is arranged in the flow path.

With this configuration, the fluid to be detected is swirled in an axial flow, and in this swirling flow, it revolves around a rotating body whose area is smaller than the cross-sectional area of the flow path, thereby making it possible to obtain a small and compact flow rate detection device with extremely low flow resistance. can.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described based on FIGS. 3 and 4. In FIG. 3, reference numeral 10 denotes a housing, and inside this housing 10, a torsion plate 11 of a swirling means for axially swirling the fluid to be detected is fixed to a casing 12. Twisted plate 11
is processed by coaxially twisting a flat plate. A rotating magnetic sphere 13 is provided downstream of the torsion plate 11 and has a smaller diameter than the cross-sectional area of the flow path that revolves in a plane perpendicular to the flow direction. As the structure of the magnetic sphere 13, a steel ball, a hollow steel ball, a sphere formed by magnetically plating resin and then resin molding is used. The magnetic sphere 13
A ball receiver 14 is provided downstream of the magnetic ball 13 as an outflow prevention means for keeping the magnetic ball 13 within the range of the swirling flow.

The casing 12 is inserted into the housing 10,
It is fixed by a C ring 15. Further, a rotation detector 18 as a detection means for the magnetic sphere 13 is provided outside the housing 10 and constitutes a flow rate detection device, which is composed of a permanent magnet 16 and a magnetoresistive element 17 which is a magnetic detection element.

19 and 20 are piping connection ports, 21 is an arrow indicating the flow direction of the fluid to be detected, and 22 is a magnetic sphere 1.
This is an arrow indicating the direction of rotation of No. 3.

FIG. 4 shows the ball receiver 14, where 23 is a conical surface on which the magnetic sphere comes into contact, and 24 is a donut-shaped flow path.

The operation of the above configuration will be explained based on FIGS. 3 and 4. When the fluid to be detected flows in from the direction of the arrow 21, the fluid to be detected flows along the torsion plate 11 and is rotated in an axial flow. As a result, the magnetic sphere 13 placed in the swirling flow gains a kinetic force from the swirling flow and rotates in the direction of the arrow 22. At this time, the magnetic sphere 13 rotates while contacting two points, the conical surface 23 of the sphere receiver 14 and the casing 12. Since the number of rotations of the magnetic sphere 13 is proportional to the flow rate, the flow rate can be measured by measuring the number of rotations of the magnetic sphere 13. The method is as follows:
A magnetic field of constant strength is applied to the magnetoresistive element 17 by the permanent magnet 16, and the resistance change of the magnetoresistive element 17 that occurs when the magnetic sphere 13 passes through this magnetic field is extracted as a voltage change and is output to a control circuit (not shown). ). Note that the area of one flow path made up of the torsion plate 11 is defined as the magnetic sphere 13.
By designing the projected area to be smaller than the projected area of , the magnetic sphere 13 will not escape to the piping connection port 19 side. Further, the number of rotations of the magnetic sphere 13 can be designed as desired by changing the number of twists and the twist angle of the torsion plate 11.

In this embodiment, since the rotating body is composed of a magnetic sphere, the contact area during rotation is small, so the contact resistance is small, and stable rotation can be obtained even in a low flow rate range. Since it is a sphere, there is little resistance when orbiting. Furthermore, since it is detected using a magnetic sensor, it can be detected even in opaque fluids.

Effects of the Invention As is clear from the above description, the flow rate detection device of the present invention includes a swirling means that axially swirls the fluid to be detected flowing in a flow path, and a rotating body that revolves in the swirling flow caused by the swirling means. , consisting of an outflow prevention means for keeping the rotating body within the range of the swirling flow, and a rotation detecting means for measuring the number of revolutions of the rotating body, and the swirling means is constituted by a torsion plate fixed to the flow path. It has the following effects.

(1) Low flow resistance. The fluid to be detected is axially swirled, and the rotating body is also configured to have a smaller diameter than the cross-sectional area of the flow path. Furthermore, in comparison with conventional ball-type flow rate sensors, the flow resistance is extremely small, as there is no extreme change in the flow path and no interference from the fluid itself.

(2) The structure of the flow rate detection device is small and compact. Unlike those in which the flow path itself forms an annular flow path, the feature is that an axial flow is generated in the straight pipe section and a rotating body is circulated, and the flow path structure is the simplest and the flow path can be configured to be short. .

(3) Low noise during orbiting. Since the sphere orbits within the flow path in the vertical direction of the flow path, its rotation diameter is small and the centrifugal frictional force with the casing is small. The noise generated by the casing is extremely small.

(4) The number of revolutions of the rotating body can be easily designed.
The turning means is composed of a torsion plate, and the number of rotations can be easily designed by changing the number of twists and the twist angle.

[Brief explanation of drawings]

1 and 2 are a horizontal cross-sectional view and a vertical cross-sectional view of a flow path of a conventional flow rate detection device, FIG. 3 is a vertical cross-sectional view of a flow rate detection device showing an embodiment of the present invention, and FIG. 4 is a spherical shape. It is a perspective view of a receiver. 11... Rotating means (twisting plate), 13... Rotating body (magnetic sphere), 14... Outflow prevention means (sphere receiver), 18... Rotation detection means (rotation detector).

Claims (1)

[Claims] 1. a swirling means for axially swirling the fluid to be detected flowing in a flow path; a rotating body located in the swirling flow caused by the swirling means and rotating in a plane perpendicular to the flow direction;
It consists of an outflow prevention means for keeping this rotating body within the range of the swirling flow, and a rotation detecting means for measuring the number of rotations of the rotating body, and the rotating means has a flat plate twisted coaxially with respect to the flow direction. A flow rate detection device comprising a torsion plate fixed to the flow path.