JPH02287217A - Flow rate detector - Google Patents

Abstract

PURPOSE:To enable detection of a flow rate stably for a long time by building up a turning means for turning a fluid in a passage with fixed vanes three in number with an angle thereof of 40-50 deg.. CONSTITUTION:A turning means 6, a magnetic ball body 7 and an anti-spillage receiving means 8 are arranged sequentially from the upstream side within a housing. The means 6 is fixed vanes, which will not turn even with a flow of a fluid, three in number as linear plane vanes with a vane angle alpha of 40-50 deg.. Then, the fluid flows into a housing 4 from the direction of the arrow and the incoming fluid is turned by the means 6 of a passage 5 so that the ball body 7 obtains a kinematic force with a spiral flow of the fluid and circulates through a cylinder 9 vertical to a direction of the passage at a position of contacting an inner wall of the cylinder 9 and the anti-spillage receiving means 8. Revolutions due to the circulation thereof are correlated to a flow rate of the fluid and revolutions of the ball body 7 are detected with a magnetic detec tor 11. Then, with the detector 11, a pulse is outputted and a computation is performed with a control circuit. The results are detected as instantaneous flow rate and integrated flow rate.

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 a 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 IT into an electrical signal and measures it. There is. An example of this is explained in Fig. 3. Fig. 0 shows a vane-wheel type flow sensor, in which an impeller 1 that is axially supported in a wave path is installed, and a permanent magnet 2 embedded in the outer periphery of the impeller is used to guide the pipe. By operating the magnetic detection sensor 3 attached outside the flow rate 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 to the inner surface of the passageway, there is a risk that rotation accuracy may deteriorate or rotation may stop.

The present invention solves these conventional problems, and provides a flow rate detector that is resistant to foreign substances without installing a bearing in the flow path, as well as a high-performance, compact device with good rotational stability even after long-term use. The object of the present invention is to provide a compact flow rate detector.

Means for Solving the Problems To achieve this object, the present invention provides a swirling means for swirling fluid in a wave path, a sphere that rotates in the swirling flow, a receiving means for preventing outflow of the sphere, It is composed of a detector that detects the rotational speed, and the rotating means is composed of fixed blades having a blade angle of 40 to 50 degrees and three blades.

Effect With the above configuration, the swirling means generates a swirling flow in the fluid,
The sphere can be stably rotated at an appropriate rotational speed, and the flow rate can be detected stably for a long period of time.

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 receiving 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 circumferential 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. The outflow prevention receiving means 8 has a central hole 14 and an arcuate hole around the periphery, and the upstream end has a flat surface and an annular shape in the direction of flow, and serves as a contact receiving means for the sphere 7 to circulate without flowing out.

The sphere 7 rotates while contacting the inner circumferential surface of a cylinder 9 that is integrally formed with the turning means 6 and the outflow prevention receiving means 8, and the upstream flat portion 10 of the outflow prevention receiving means 8. 11
is a magnetic detector, which is composed of a magnetic resistance element or a Hall element and an amplifier circuit, and a bias magnetic field is applied by a permanent magnet 12 installed near or in contact with the magnetic detector 11.
The rotation speed of the magnetic sphere 7 is detected as a pulse output, and is molded with resin using 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 turning means 6 will be described. The rotating means 6 is a fixed blade that does not rotate even with the flow of fluid, and has a blade angle α
It is formed with a straight plane of 40 to 50 degrees and three blades. When the blade angle is small, the rotational speed of the fluid is low, and when the angle is large, the rotational speed of the fluid increases, and the level of rotational speed of the sphere changes accordingly.0 If the rotational speed of the sphere is low, the flow rate is detectable. On the other hand, if the rotation speed becomes too high, there may be problems with the wear of the sphere and the generation of noise due to rotation, making it difficult to use as a flow rate detector. There is an appropriate rotational speed, that is, an appropriate blade angle α, which is the above 40
The value is ~50 degrees. In addition, when the number of blades increases, the length of the blade in the wave path direction becomes impossible, and even at the same angle, the energy to swirl the fluid decreases, and when considered as a blade with the same water flow resistance at the same angle, the efficiency of swirling the fluid becomes poor. Become. Therefore, a three-blade blade that provides smooth and efficient rotation is appropriate. Furthermore, as shown in Fig. 2, in order to make the blade a fixed blade that does not rotate due to the force of the fluid, there are flow channels on the outer periphery.
Three protrusions 15 having a diameter slightly larger than the inner diameter are provided at equal intervals. With this configuration, insertion into and removal from the flow path is easy, and the wing can be easily formed as a fixed wing without using separate parts for fixation.

Next, the outer diameter of the magnetic sphere 7 is slightly larger than the inner diameter B of the cylindrical body 9 of the flow path. That is, the diameter of the swirling means 6 is selected to be the minimum diameter at the efficient and effective blade angle, taking into account the water flow resistance and the relationship that imparts swirling force to the fluid. Among them, the diameter of the sphere 7 is selected so as not to cause a large water flow resistance. This is because when the sphere 7 becomes a movable body and rotates in contact with the inner surface of the cylindrical body 9 and the upstream flat part 10 of the outflow prevention receiving means 8, if the fluid contains hard, minute foreign matter, etc.
Over a long period of time, the sphere may become scratched, and if the sphere is relatively small, there is a risk that it will get caught in the wing or flow out through the central hole 14 of the outflow prevention receiving means 8. In consideration of this point and to the extent that it does not affect water flow resistance, the sphere is provided with a diameter slightly larger than 2 of the inner diameter of the cylindrical body 9.

Next, the center hole 14 of the outflow prevention receiving means 8 is provided at a diameter of two or less of the diameter of the sphere 7. This is because when the diameter of the sphere 7 occupies a certain size with respect to the flow path as described above, the diameter of the central hole 14 of the outflow prevention receiving means 8 changes the flow rate of the fluid by rotation of the sphere due to the swirling flow. It comes to have an influence on the relationship between numbers. If the inner diameter of the central part 14 is large, the flow rate passing through it will also increase,
The fluid flowing near the center of the channel increases, and the centripetal force causes the sphere 7 to
The force to rotate the engine also increases, and as a result, the linear characteristic relationship between flow rate and rotational speed is disrupted. Therefore, there is an inner diameter of the central hole 14 that satisfies this relationship, and this is the inner diameter of the center hole 14 that satisfies this relationship.

In the above configuration, fluid flows into the housing 4 from the direction of the arrow in FIG. It goes around inside the cylindrical body 9 in a direction perpendicular to the direction of the flow path at a position where it contacts the inner wall of the body 9 and the outflow prevention receiving 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 detected by the magnetic detector 11.
Detect with. The magnetic detector outputs a pulse, which is calculated by a control circuit (not shown) and detected as an instantaneous flow rate or an integrated flow rate.

Effects of the Invention As described above, the present invention provides a flow rate detector that is resistant to foreign matter without providing a bearing in the flow path, and further provides the following effects.

(1) The blade angle and number of blades are appropriately selected to provide smooth and efficient rotation speed, and to maintain stable characteristics even during long-term use.

[2] The configuration for forming a fixed wing is extremely simple, and a fixed wing that is easy to install and remove can be formed by simply providing protrusions at several locations on the outer periphery of the wing.

(3) The relationship between the outer diameter of the sphere with respect to the flow path diameter and the inner diameter of the central hole of the outflow prevention receiving means with respect to the outer diameter of the sphere is appropriately selected, and it is durable and strong against fluids containing foreign matter, and has characteristics. Stability is also improved.

That is, the present invention provides a high-performance, small and compact flow rate detector that has good flow rate rotational speed characteristics regardless of the quality of the fluid, and has good rotational stability even when used for a long period of time.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the flow path of a flow rate detector according to an embodiment of the present invention, Fig. 2 is a front view of the fixed blade, which is the rotating means, in the flow path direction, and Fig. 3 is a flow path showing a conventional flow rate detector. FIG. 5...Flow path, 6...Swivel means, 7...
... Sphere, 8... Outflow prevention receiving means, 11.
...Detector, 14...Central hole, 15...
····protrusion. Name of agent: Patent attorney Shigetaka Awano

Claims (4)

[Claims] (1) A swirling means for swirling the fluid in the flow path, a sphere located in the swirling flow and performing rotational movement, and an outflow prevention receiving means for keeping the sphere within the range of the swirling flow; The flow rate detector is composed of a detector that detects the rotational speed of the sphere, and the rotating means is formed by three fixed blades with a blade angle of 40 to 50 degrees. (2) The flow rate detector according to claim 1, wherein the fixed vane has a diameter slightly larger than the inner diameter of the flow path and is provided with protrusions at several locations on the outer periphery of the fixed blade. (3) The flow rate detector according to claim 1, wherein the sphere has a diameter larger than 1/2 of the flow meter. (4) The flow rate detector according to claim 1, wherein the outflow prevention receiving means has a flow path on the outside and inside of the flow path, and the inside center hole has a diameter of 1/2 or less of the diameter of the sphere.