JPH02107921A - Flow rate detector - Google Patents

Abstract

PURPOSE:To enable detection of revolutions and a flow rate by providing a whirling means to make a ball turn smoothly with a spiral flow generated of a fluid. CONSTITUTION:A whirling means 6, a magnetic ball 7 and a outflow preventing means 8 are arranged in a housing 4 forming a passage 5 sequentially from the upstream side. Here, the means 6 is a fixed impeller having a plurality of blades and the ball 7 is a double-layer ball wherein a magnetic metal 15 is made as hollow part 14 inside and is molded by a resin 16 outside and the means 8 has a central hole 8a and an ambient arcuate hole 8b to be in contact with the ball 7. Then, when a fluid flows into the housing 4 from the direction of the arrow, it is whirled by the means 6 and the ball 7 is cirulated through a cylinder 9. Thus, when a biased magnetic field is applied with a permanent magnet 12 to detect revolutions of the ball 7 by a magnetic detection means 11 and an output pulse of the means 11 is computed, an instantaneous flow rate and an integrated flow rate can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a flow rate detector that detects the flow rate of water or hot water in a water heater or hot water heater, or the fuel flow rate in a liquid fuel supply device.

Conventional Technology There are various methods for measuring flow rate, and one simple method that can be applied to general consumer equipment is one that converts the rotational speed of a movable body such as an impeller that rotates in proportion to the flow rate into an electrical signal. There is. An example thereof will be explained in FIG. The figure shows a vane-wheel type flow sensor, in which an impeller 1 supported by an axis is provided in the flow path, and a magnetic detection sensor 3 is attached outside the pipe by means of a permanent magnet 2 embedded in the outer periphery of the impeller. By operating the pump and detecting its rotation, a pulse output with a frequency proportional to the flow rate is obtained.

Problems to be Solved by the Invention However, with the above configuration, there is a risk that foreign matter may enter the bearing in the flow path, resulting in a decrease in rotational speed accuracy or deterioration of the bearing, and there is a risk that foreign matter may enter the permanent magnet in the flow path. If it adheres and reaches the inner surface of the passage, there is a problem in that there is a risk of deterioration of rotation accuracy or rotation stoppage.

The present invention is intended to solve such conventional problems, and aims to provide a flow rate detector that is resistant to foreign matter without providing a bearing in the flow path.

Means for Solving the Problems In order to solve the above problems, the present invention provides a swirling means for swirling fluid in a flow path, a sphere that rotates in the swirling flow downstream of the swirling means, and a sphere that rotates the fluid in the flow path. A flow rate detector comprising an outflow prevention means for stopping the swirling flow within a range, a detection means for detecting the number of revolutions of the sphere, and a configuration in which the sphere is made of a material whose hardness is lower than that of the outflow prevention means. be.

Effect With the above configuration, the swirling means generates a swirling flow in the fluid,
Rotation speed and flow rate can be detected by rotating the sphere smoothly.

Example Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, 4 is a housing forming a flow path 5;
Inside the housing 4, a rotating means 6, a magnetic sphere 7, and an outflow prevention means 8 are provided at appropriate intervals in order from the upstream side.

The swirling means 6 is a fixed impeller that does not rotate and has a plurality of blades twisted in the same direction between the outer periphery and the center, and gives a swirling flow to the fluid.

The magnetic sphere 7 does not have a magnetic effect by itself, but is a resin sphere with a magnetic metal or the like inserted inside. Outflow prevention means 8
has a central hole 8a and an arcuate hole 8b around it, and the upstream end is flat and has an annular shape in the direction of flow, and serves as a contact receiving point for the sphere 7 to circulate without flowing out. The sphere 7 is the turning means 6
It rotates while contacting the inner circumferential surface of the cylinder 9 which is integrally formed with the outflow prevention means 8 and the upstream flat portion 10 of the outflow prevention means 8. Reference numeral 11 denotes a magnetic detection means, which is composed of a magnetic resistance element or a Hall element and an amplifier circuit, and a permanent magnet 12 provided near or in contact with the magnetic detection means 11 applies a bias magnetic field to pulse the rotation speed of the magnetic sphere 7. It is detected as an output, and is resin-molded with a molding material 13 and fixed to the outside of the housing 4 on the outer periphery of the rotation orbit of the sphere 7.

Next, details of the magnetic sphere 7 are shown in FIG. FIG. 2 is a cross-sectional view of the magnetic sphere 7, which has a two-layer spherical structure in which a spherical magnetic metal 15 having a hollow portion 14 is inserted, and the outside is molded with resin. When the outflow prevention means 8 is made of resin, the resin molding material 16 is made of a soft material having a lower hardness than the resin.

In the above configuration, fluid flows into the housing 4 from the direction of the arrow in FIG. It circulates within the cylindrical body 9 in a direction perpendicular to the direction of the flow path at a position where it comes into contact with the inner wall of the body 9 and the outflow prevention means 8. The number of rotations due to the rotation is correlated with the flow rate of the fluid, and in this configuration, there is a proportional relationship, and the number of rotations of the magnetic sphere 7 is determined by the magnetic detection means 11.
Detect with. The magnetic detection means 11 outputs a pulse,
It is calculated by a control circuit (not shown) and detected as an instantaneous flow rate or an integrated flow rate. The rotational speed level of the sphere 7 can be appropriately set depending on the application, for example, by selecting the twisting angle of the impeller of the turning means 6.

Next, the subject matter of the present invention will be described. . When this flow rate detector is used in a device that carries household water in a fluid, especially when pumping well water and using it as tap water, the well water contains hard particles (from several microns to several tens of microns). It often contains microscopic stones such as silica and alumina). When these particles are caught in the movable contact portion of the flow rate detector, the movable contact portion is polished. That is, the compressed particles bite into the soft material, and the hard material is polished by the particles. In this configuration, the sphere 7 has a large movable surface pressure with the outflow prevention means 8, so if the outflow prevention means 8 is made of a soft material, the fine particles at the tip will bite into the outflow prevention means 8, and as a result, the sphere The rotational movement of the sphere 7 polishes the sphere, causing a dimensional change, which affects the movement of the sphere 7. However, in the present invention, since the sphere 7 is made of a softer material than the outflow prevention means 8, the fine particles bite into the sphere 7 side and adhere to it, polishing the outflow prevention means 8 side. However, the amount of abrasion at that time is extremely small compared to the spherical body, and even if it is polished, the movement of the spherical body 7 is not affected. Therefore, reliable and reliable measurement is possible. When the outflow prevention means or its upstream flat portion 10 is formed of metal, the above effect becomes even more remarkable.

In the above configuration, the material of the sphere 7 is not particularly limited, such as changing depending on the type of fluid, but the minimum detectable flow rate of the fluid can be lowered by using a lightweight non-metallic material such as resin. It is advantageous. Although a fixed impeller is used in the embodiment as a means for causing a swirling flow in the fluid, there are various means such as a flat plate torsion member and a cylindrical member with several diagonal holes, and there is also an outflow prevention means that does not allow a sphere to pass through. It is also possible to use a flat plate with a large number of holes. In the configuration of the embodiment, the impeller as a fluid swirling means has less resistance and is effective in generating a stronger swirling flow, and the annular shape with a flat part as an outflow prevention means makes the sphere circular. Each of these configurations is advantageous, such as being effective for stable orbiting, but there are many methods available depending on the type of fluid and required performance level, and the above methods are not limited to the configurations of the embodiments. do not have. Furthermore, the flow path is not limited to a circular cross section. As described above, the present flow rate detector has a simple structure and high accuracy, is resistant to foreign substances in the fluid, has low water flow resistance, and can measure flow rates over a wide range.

Effects of the Invention As described above, the flow rate detector of the present invention provides the following effects.

(1) The structure is such that the liquid is swirled by a swirling means such as a fixed impeller, and the swirling flow rotates the sphere, and there are no narrow parts in the passage such as bearings, rotary blade tips, and the inner diameter of the passage. There is no risk of rotation deterioration or rotation stoppage due to foreign objects, and it is reliable as it will not affect moving parts even when exposed to water containing fine particles ranging from a few microns to several tens of microns, such as well water or red rust in pipes. The present invention provides a flow rate detector with high performance.

(2) The rotating sphere can be made of resin, and is easy to operate even with a small flow rate, and has a wide detection flow range as a flow rate detector.Moreover, the kinetic energy due to rotation is small, and wear and noise caused by contact rotation are extremely small.

(3) The rotating means, the sphere, and the outflow prevention means have extremely low resistance with respect to the passage diameter, and the flow passage and structure are simple and compact as a flow rate detector, making it suitable for application to equipment.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a flow path of a flow rate detector according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a sphere, and FIG. 3 is a sectional view of a flow path showing conventional flow rate detection. 5...Flow path, 6...Swivel means, 7...
... Sphere, 8... Outflow means, 11...
...Detection means.

Claims (2)

[Claims] (1) A swirling means for swirling the fluid in the flow path, a sphere located in the swirling flow and performing rotational movement, an outflow prevention means for keeping the sphere within the range of the swirling flow, and the A flow rate detection device comprising a detection means for detecting the number of rotations of a spherical body, the spherical body being made of a material having a lower hardness than the outflow prevention means. (2) The flow rate detection device according to claim 1, wherein the sphere is made of a resin material, and the outflow prevention means is made of metal at least at least a portion that contacts the sphere.