JPS63153430A - Flow rate detector - Google Patents

Abstract

PURPOSE:To obtain an output of two pulses per one rotation of a ball, and to improve the resolution for measuring a flow rate, by executing a detection of turning of the ball by light emitting and light receiving elements provided on the peripheral wall of a housing, in a ball turning type flow rate detector. CONSTITUTION:In a housing 1 for forming a passage of a fluid 2, a fixed impeller 3 for giving a turning flow to the fluid 2 is placed, and on the downstream of this impeller 3, a fluid turning chamber 13 is provided. In the rear part in the fluid turning chamber 13, an outflow preventing means 5 for preventing an outflow of a non-metallic sphere 4, and also, being used as a receiver at the time of turning of the sphere is provided. Also, said housing 1 is provided with a light emitting element 7 and a light receiving element 8 for detecting the turning of the sphere 4. According to such constitution, at the time of turning of the sphere 4, two pulses per one rotation of the sphere 4 are outputted from the light receiving element 8, therefore, a flow rate detection having high resolution can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the overall structure of a flow rate sensor for measuring the flow rate of fluid.

Conventional technology There are various types of flowmeters such as electromagnetic flowmeters that are used as so-called measuring instruments to measure the flow rate of fluids, but they are not used as flowmeters (as flow rate sensors for equipment that handles fluids or automobiles, etc.). The number of applications in which it is used has been increasing in recent years, and in this case, there is a need for a small type that is easy to incorporate into equipment, etc.One type of flow sensor is a ball-circulating flow sensor whose sensor part has a relatively simple configuration. The conventional example is explained in Fig. 2 and Fig. 3. In both figures, 101
An inlet passage 102 and an outflow passage 103 are opened on the outer periphery of the annular passage having a circular cross section, and a sphere 104 is inserted into the annular passage 101 . The fluid flows through the inlet passage 10 while circulating inside the annular passage 101 in the direction of the solid arrow in the figure.
2 to the outflow passage 103, and together with it the ζ sphere 104.
It moves around inside the annular passage in the direction of the dashed arrow 3. Since the rotational speed of this sphere is proportional to the flow rate of the fluid, the rotational speed of the sphere is detected in a pulsed manner by an optical sensor (not shown), and the flow rate is measured through a control circuit. FIG. 3 is similar to FIG. 2, except that the outflow passage 103 is configured to flow out from the center of the annular passage 101 in a direction perpendicular to the flow path surface.

In either case, the problems with these conventional examples are:
The reason for this is that the flow resistance is large. Since the annular passage is formed, the inlet and outlet of the flow passage change direction, causing bending loss, and the circular flow intersects with the inflow flow near the inflow passage, causing inflow resistance and loss, and furthermore, the rotation of the sphere causes loss. If the sphere is formed to have a size close to the cross section of the annular passage, it will also result in a large flow passage resistance. In addition, if a nozzle is provided in the inflow passage 102 to make the rotation of the sphere smooth, the flow resistance becomes even greater. Second, there are structural problems, such as the fact that the sensor structure tends to be large.

As mentioned above, the passage resistance increases, so it is necessary to increase the passage diameter to reduce it.Also, since an annular passage is formed compared to a normal straight pipe, a corresponding space is required, and the sensor as a whole It is larger than the front and rear passages.

In addition, the direction of the outflow passage 103 with respect to the inflow passage 102 is limited to some extent, which poses problems such as constraints on the structure when incorporating it into equipment as a sensor, and the overall size tends to increase. Thirdly, since the sphere revolves around the annular passage 101, which tends to be relatively large, its momentum is large, and there are disadvantages in characteristics such as large noise when the sphere rubs against the outer peripheral surface of the annular passage.

Other conventional examples include Japanese Unexamined Patent Application Publication No. 50-51758 and Japanese Utility Model Application No. 47-3762.

However, in JP-A-50-51758, since the ball is in contact with three points, when the flow rate suddenly changes, the contact points of the ball (at least two points) change due to a change in centrifugal force, and the ball does not rotate. There is a problem with stability. In addition, since there is a central boss at the center of the ball rotation position, the diameter of the ball 5 is limited to the diameter of the ball that fits between the outer periphery of the central boss and the outer periphery of the flow path. be done. Therefore, it is difficult to take measures to vary the detection range by changing the ball diameter. Furthermore, since a second spinner for rectifying the flow is provided on the downstream side of the ball, there is a problem in that the pressure loss in this rectifier is large.

On the other hand, Japanese Utility Model Application Publication No. 47-3762 has a structure in which a rotating object is simply stopped from flowing downstream by a grid, and it is judged that it is impossible to orbit a rotating object in a fixed orbit.

(The publication does not disclose the technology for orbiting an object in the same orbit.) Therefore, the configuration was insufficient as a function of a flow rate detection device. It was also said that when the swirling flow passes through the grid, there is a large pressure drop.

Problems to be Solved by the Invention The present invention aims to improve the accuracy of flow rate detection by eliminating the number of pulses per revolution as much as possible without making the rotation of the sphere unstable.

Means for Solving Problems 6-7 In order to achieve the above object, the present invention swirls the fluid within the cross-sectional range of the flow channel by means of a fluid swirling means provided in the flow channel, and the swirling flow causes The flow rate is determined by a mechanism in which a nonmetallic sphere is orbited in a direction perpendicular to the flow direction, and the rotational speed of the nonmetallic sphere is detected by a light emitting element and a light receiving element provided in the radial direction of the orbital surface of the nonmetallic sphere. This constitutes a detection device.

Operation With the above configuration, pulses at regular intervals can be extracted as a flow rate signal.

Example An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a housing for forming a flow path 2;
A fixed impeller 3, which does not rotate, is fixed to the upstream side of the housing by press fitting or the like to give a swirling flow to the fluid. On the downstream side of the impeller 3, there is a sphere 4 made of opaque resin that circulates in the flow path due to the swirling flow of the fluid, and a 7-hole for preventing the sphere 4 from flowing downstream and for the sphere 4 to circulate. There is an outflow prevention member 5 that serves as a receiver. A sphere 4 and an outflow prevention member 5 are also housed in the housing 1, and the outflow prevention member 5 is housed in the housing 1.
It is fixed by press-fitting, etc. The outflow prevention member 5 has a tapered donut shape in which the cross section of the part where the sphere 4 comes into contact and revolves is enlarged toward the upstream side with the inner wall of the flow path, and the cross section of the part where the sphere 4 comes in contact with and revolves is formed in a tapered donut shape, and the part where the sphere 4 comes into contact with the fixed impeller 3 is formed. Located at an appropriate distance.

In addition, the spherical rotating chamber 13 provided between the fixed impeller 3 and the outflow prevention member 5 is configured to generate a swirling flow over the entire area from the center of the channel to the inner wall of the channel.
goes around. Furthermore, in order to detect the number of revolutions of the orbit of the sphere 4, a through hole 6 is provided in the outer layer of the housing of the orbiting part of the sphere, and a through hole 6 that crosses the flow path 1 is provided, and a light emitting element 7 and a light receiving element 8 are provided at a position opposite to the light emitting element 7. It is desired that the head of each element does not protrude into the flow path, and a sealing member such as a rubber gasket 9.9
' and fixed to the housing 1 with an adhesive or the like, and terminals and lead wires 10° and 10' of the element are drawn out to the outside. The above is the flow rate detection device.

11, the housing 1 is formed in a form similar to a normal piping member, and the inlet/outlet of the flow path is configured with female threads 12, 12' to enable direct connection to normal piping. The above is the configuration, and the operation will be described next.

In the flow rate detection device 11, fluid flows into the housing 1 from the direction of the arrow in the figure, the inflowing fluid is swirled by the fixed impeller 3, and the swirling flow of the fluid gives the sphere 4 a motion force, and the outflow prevention member 5 It circulates within the flow path 2 in a direction perpendicular to the direction of fluid flow at a position where it contacts the inner wall of the housing.

The number of rotations caused by the rotation is correlated with the flow rate of the fluid, and in the case of this configuration, there is a proportional relationship, and the flow rate of the fluid is measured by optically detecting the number of rotations of the sphere using the light emitting element 7 and the light receiving element 8. The sphere is an opaque body, and the only thing that blocks light between the light emitting element and the light receiving element is the sphere, and two pulses are output per one rotation of the sphere, and a control (not shown) to which lead wires 10 and 10' are connected. This will be detected as a flow rate by the circuit. The material of the sphere 49 is not particularly specified, 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 material such as a non-metallic material such as resin. It will be advantageous. Although a fixed impeller is used in the embodiment as a means for causing a swirling flow in the fluid, there are various other means such as a flat plate torsion member and a cylindrical member with several diagonal holes. It is also possible to use a flat plate with a large number of holes that cannot be passed through. In the configuration shown in the example, the impeller as the fluid swirling means has less resistance and is effective in generating a stronger swirling flow, and the tapered cross-sectional shape as the outflow prevention means stabilizes the sphere in the same orbit. Each of these configurations is advantageous, such as being effective for circulating the fluid, but as described above, there are many different means depending on the type of fluid and the required detection performance level, and the configuration is particularly limited to the configuration of the embodiment. It's not something you can do. Furthermore, the flow path is not limited to a circular cross section except for the circumferential portion of the sphere. In addition, the flow rate detection device 11
Flow rate sensor 10 for water, gas, and air in water heaters, gasoline, water, and air in automobiles, etc.

It is applied to various devices and machines, and the inlet/outlet has a piping screw structure, so it can be configured as part of the fluid passage.

Effect of the invention The above is the configuration of the present invention, and the effects will be described next.

(I) There is no need for the conventional flow path itself to form an annular flow path, and an axial flow is generated in a general flow path such as a straight pipe over the entire area from the center of the flow path to the inner wall to rotate the sphere. By detecting the rotation of the sphere using a light-emitting element and a light-receiving element that are arranged so that the sphere is the only thing blocking light in the radial direction of the orbital surface of the sphere, the minimum detected flow rate can be lowered by reducing the weight of the sphere. In addition to this effect, since two pulses of output can be obtained per one rotation of the sphere, the resolution in flow rate measurement can be improved. In particular, the use of a sphere and the ability to obtain two pulses of output with a pair of elements are
This has an advantageous effect in terms of cost.

in) The sensor part consists of a rotating means such as an impeller, a sphere, and an outflow prevention means.
The means for causing swirling has low resistance relative to the flow path diameter,
The sphere also revolves around the axial flow within the flow path and has a much smaller diameter than the flow path diameter, and the outflow prevention means also has a donut shape that does not prevent swirling flow, so the flow resistance as a whole is extremely small. Also, in comparison with conventional ball-type flow sensors, there is no extreme bend in the flow path, there is no interference with the flow itself, and the size of the sphere is smaller in diameter than the flow path, resulting in lower fluid flow resistance. becomes extremely small.

(2) By constructing the outflow prevention means in a donut shape with a cross-section of the flow path expanding toward the upstream side, the sphere orbits the same orbit while always touching the raceway surface of the outflow prevention means at two points, resulting in high detection accuracy. . In addition, even when the flow rate changes suddenly during flow rate measurement, the sphere is always in contact with the raceway surface of the outflow prevention means at two points due to the force applied to the downstream side of the fluid, and the trajectory of the sphere does not change. This also has the effect of ensuring detection accuracy.

Having the above-mentioned effects, the flow rate detection device of the present invention can be greatly applied to equipment and the like.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a flow path of a flow rate detection device according to an embodiment of the present invention, and FIGS. 2 and 3 are cross-sectional views of a flow path of a conventional ball-circulating flow rate sensor. 2...Flow path, 3...Fixed impeller, 4.
... Sphere, 5 ... Outflow prevention member, 7 ...
...Light emitting element, 8... Light receiving element, 11...
...Flow rate detection device. Name of agent: Patent attorney Toshio Nakao and one other person
C li \(Q Mi \ -NO) comparison

Claims (3)

[Claims] (1) A swirling means for axially swirling the fluid provided in a flow path, a sphere located in the swirling flow and circulating in a direction perpendicular to the flow direction, and a sphere that is placed within the range of the swirling flow. a detection means for detecting the number of rotations of the spherical body; and a detection means for detecting the number of rotations of the sphere; A flow rate detection device comprising a spherical orbiting chamber that generates a swirling flow over the entire area, and the detection means comprising a light emitting element and a light receiving element provided in the radial direction of the orbital surface of the sphere. (2) The flow rate detection device according to claim 1, wherein the outflow prevention means has a donut shape with a cross section of the flow path expanded toward the upstream side. (3) The flow rate detection device according to claim 1, wherein the sphere is made of a non-metallic material.