JPS6326845B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the overall configuration of a flow rate sensor that measures the flow rate of fluid.

Configuration of conventional examples and their problems There are various types of flowmeters, such as electromagnetic flowmeters, which are so-called measuring instruments as a means of measuring the flow rate of fluid, but they are not used as flowmeters, but are used in equipment that handles fluids, automobiles, etc. In recent years, applications for use as flow rate sensors have been increasing, and in this case, there is a need for a type that is small and easy to incorporate into equipment. One type of such flow sensor is a ball-circulating flow rate sensor whose sensor part has a relatively simple configuration, and a conventional example thereof will be explained with reference to FIGS. 1 and 2. In both figures, 101 is an annular passage with a circular cross section, and an inflow passage 102 and an outflow passage 103 are opened on the outer periphery of this passage.
A sphere 104 is inserted into the annular passage 101 . The fluid flows through the annular passage 10 in the direction of the solid arrow in the figure.
The sphere 104 circulates within the annular passage 102 and flows from the inflow passage 102 to the outflow passage 103, and at the same time, the sphere 104 also moves around the annular passage in the direction of the dashed arrow. 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. 2 is similar to FIG. 1, 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 first problem with these conventional methods 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 inflow passage 10
In contrast to No. 2, the direction of the outflow passage 103 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. Another conventional example is JP-A-50-
There are No. 51758 and Utility Model Application Publication 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 (at least two points) of the ball change due to changes in centrifugal force, and the ball does not rotate. There is a problem with stability. Furthermore, since the ball has a central boss at the center of the rotational position, the diameter of the ball is limited to a diameter that fits between the outer periphery of the central boss and the outer periphery of the flow path. Therefore, the configuration makes it difficult to change the detection range by changing the ball diameter. Furthermore, a second spinner for rectification is provided downstream of the ball, so
Another problem was that the pressure loss in this rectifying section was large.

On the other hand, Utility Model Application Publication No. 47-3762 has a configuration in which a rotating object is simply stopped from flowing downstream by a lattice, and it is difficult to orbit a rotating object in a fixed orbit, and the swirling flow passes through the lattice. It is also assumed that there is a large pressure loss when passing through.

Purpose of the Invention In view of the above-mentioned drawbacks of the conventional flow rate sensor, the present invention has been made to
The purpose of the present invention is to provide a high performance, small and compact flow rate detection device that can be easily applied to flow rate sensors for devices that handle fluids, automobiles, etc.

Structure of the Invention In order to achieve the above object, the present invention includes a fixed impeller that is provided in a flow path and rotates a fluid in an axial flow, and a fixed impeller that is located in the swirling flow and rotates in a direction perpendicular to the flow direction. A spherical body, an outflow prevention means for stopping the spherical body within the range of the swirling flow, a detection means for detecting the number of rotations of the spherical body, and a flow prevention means provided between the fixed impeller and the outflow prevention means. and a spherical circulating chamber that generates a swirling flow over the entire area from the center of the channel to the inner wall of the channel, and the outflow prevention means has a donut-shaped chamber in which the cross section of the channel around which the sphere circulates is enlarged toward the upstream side. This constitutes a flow rate detection device having an outflow prevention means section, and one embodiment of the present invention will be described below with reference to the drawings.

DESCRIPTION OF THE EMBODIMENTS In Fig. 3, numeral 1 denotes a housing for forming a flow path 2, and a fixed impeller 3 that does not rotate is fixed by press-fitting or the like on the upstream side of the housing to give a swirling flow to the fluid. There is. On the downstream side of the impeller 3, there is an opaque resin sphere 4 that circulates in the flow path due to the swirling flow of the fluid, and an outflow that prevents the sphere 4 from flowing downstream and serves as a receiver for the sphere 4 to circulate. There is a prevention member 5. The sphere 4 and the outflow prevention member 5 are also housed in the housing 1, and the outflow prevention member 5 is fixed to the housing 1 by press fitting or the like. 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 is connected to the fixed impeller 3 around which the sphere 4 can circulate. Located at an appropriate distance.

Further, 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, and the sphere 4 circulates in this swirling flow. do. Furthermore, in order to detect the number of revolutions of the orbit of the sphere 4, a through hole 6 is provided in the housing on the outer periphery of the orbit 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 through hole 6. It is desired that the head of each element does not protrude into the flow path, and is sealed with sealing members 9, 9' such as rubber gaskets and fixed to the housing 1 with an adhesive or the like, and the terminals and lead wires 1 of the elements are externally connected.
0,10' are drawn out. The above is the overall configuration of the flow rate detection device 11. The housing 1 is formed in a form similar to a normal piping member, and the entrance and exit of the flow path is configured with female screws 12 and 12' so that it can be directly connected to normal piping. has been done. The above is the configuration, and the operation will be described next.

In the flow path 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 and the inner wall of the housing, the fluid circulates within the flow path 2 in a direction perpendicular to the direction of fluid flow. 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 revolution 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 4 is not particularly specified, as it can be changed depending on the type of fluid, but using a lightweight material such as a non-metallic material such as resin is advantageous in that the minimum detectable flow rate of the fluid can be lowered. becomes. 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 having several diagonal holes. The impeller as a fluid swirling means shown in the example has less resistance and is effective in generating a stronger swirling flow, and the tapered cross-sectional shape as an outflow prevention means allows it to rotate stably in the same orbit as the sphere. It is effective for
However, the flow path is not limited to a circular cross section except for the circumferential portion of the sphere. The flow rate detection device 11 is applied to various devices and machines as a flow rate sensor for water, gas, and air in water heaters, gasoline, water, and air in automobiles, and the inlet and outlet are configured with pipe screws. and can be configured as part of the fluid passageway.

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

() Since the outflow prevention means is equipped with a donut-shaped outflow prevention means part that expands the cross section of the flow path around which the sphere revolves toward the upstream side, the sphere always contacts the raceway surface of the outflow prevention means part at two points and remains in the same position. Detection accuracy is high because it orbits. 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, even in transient conditions. This has the effect of ensuring detection accuracy.

() The sensor part consists of a fixed impeller, a sphere, and an outflow prevention means.The fixed impeller has low resistance relative to the flow path diameter, and the sphere also rotates in the flow path against the axial flow, so the resistance is one step higher than the flow path diameter. Since the diameter is small and the outflow prevention means is donut-shaped so as not to impede the swirling flow, the flow resistance as a whole is extremely small. Also, in comparison with conventional ball-type flow rate sensors, there is no extreme bending of the flow path. There is no interference with the flow itself, and the size of the sphere is smaller than the flow path, so the flow resistance of the fluid is extremely small.

() Since there is no boss in the center of the channel around which the sphere revolves, it is possible to vary the diameter of the sphere. This makes it possible to change the rotation speed of the sphere, making it possible to arbitrarily set the rotation speed depending on the type of fluid, allowing for the optimal design for the application. Furthermore, since there is no boss at the center, it is possible to obtain an output signal of two pulses per revolution of the sphere in optical detection, which also has the effect of improving resolution during measurement.

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

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a flow path of a conventional ball-circulating flow rate sensor, and FIG. 3 is a cross-sectional view of a flow path of a flow rate detection device of the present invention. 2... Channel, 3... Fixed impeller, 4... Sphere,
5... Outflow prevention member, 7... Light emitting element, 8... Light receiving element, 11... Flow rate detection device.

Claims (1)

[Scope of Claims] 1. A fixed impeller provided in a flow path for axially swirling the fluid, a spherical body located in the swirling flow and rotating in a direction perpendicular to the flow direction, and a fixed impeller that is disposed in a flow path and rotates the fluid in an axial direction; an outflow prevention means for stopping the flow within a range of the flow; a detection means for detecting the number of revolutions 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 circulating chamber that generates a swirling flow over the entire area up to the inner wall of the passage, and the outflow prevention means has a donut-shaped outflow prevention means section in which a cross section of the flow passage around which the sphere circulates expands toward the upstream side. . 2. The flow rate detection device according to claim 1, wherein the sphere is formed of a non-metallic material.