JPH01189519A - Flow rate detector - Google Patents

Abstract

PURPOSE:To measure the flow rate of a fluid to be detected with high accuracy, by detecting a pulse signal generated by blocking a light path by a sphere whirling in a vortex chamber along with the fluid. CONSTITUTION:A vortex chamber 18a is provided in a transparent vortex case 18 and an inflow port 17 is allowed to communicate with the outer periphery of the vortex chamber 18a in the tangential direction of said chamber 18a and an outflow port 19 is provided to the vortex chamber 18c from the center of the bottom surface thereof in a vertical direction. Here, when a fluid flows in the vortex chamber 18a from the direction shown by an arrow H to whirl, a rotary ball 20 is whirled with the whirling of the fluid while presses the inner wall of the chamber 18a and the whirling number of rotations thereof are proportional to a flow rate. Therefore, when the currents flowing to a photodetector 22 at the times when the light from the light emitting element 21 is blocked and not blocked by the ball 20 are converted to pulses by a control circuit, a flow rate signal can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a ball-rotating flow rate detection device that detects the amount of fluid flowing in a flow path by rotating a ball.

BACKGROUND OF THE INVENTION Conventionally, there have been two types of ball-rotating flow rate detection devices: a magnetic detection method and an optical detection method. The magnetic detection method is used when there are IJ-do wires, etc. that have high current flowing around them.
It has the disadvantage that it is easily influenced by the magnetic field generated by the lead wire.

On the other hand, the optical detection method has the advantage of not being affected by the surrounding magnetic field.
Publication No. 4 had the following structure.

As shown in FIGS. 6 and 6, reference numeral 1 denotes an annular flow passage having a circular cross section, and an inflow passage 2 and an outflow passage 3 are opened at the outer periphery of this flow passage. This inflow passage 2 is provided with a nozzle 4 . Further, a sphere 5 is pushed into the annular flow path 1, transparent windows 6 and 7 are formed, and a light emitting element 8 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.
At the same time, the sphere 5 also moves around inside the annular flow path 1 in the direction of the solid arrow in the figure. Since the number of rotations of this sphere is proportional to the flow rate of the fluid, the rotation of the sphere 6 blocks the light beam between the light emitting element 8 and the light receiving element 9, which is detected as a pulse signal and passed through the control circuit to control the flow rate. Measure.

Problems to be Solved by the Invention However, in such a configuration, the annular flow path 1
, the area in contact with the fluid to be detected was large, and the flow resistance was also large. Therefore, when the flow of tap water is used as the fluid to be detected, Ca ions, etc. contained in the tap water will accumulate in the annular flow path 1, etc., and scale will grow, making it difficult for the sphere 6 to orbit normally, or causing the scale to emit light. There was a problem in that the light from the element 8 was difficult to reach the light receiving element 9. Further, the annular flow path 1 and the light emitting elements 8 . Since the light receiving element 9 is sandwiched, a relatively large space is required and the degree of freedom in arrangement is small. Therefore, it has had the problem of not being able to meet recent demands for smaller and more compact devices. Furthermore, in the method of rotating the rotating sphere 5 in the annular flow path 1, the resistance to rotation of the sphere is fundamentally large, and it is difficult to show a linear correlation between the flow rate and the rotation speed of the sphere, and it is difficult to perform highly accurate flow control. I couldn't do it.

The present invention solves the above problems and provides a flow rate detection device that is compact and capable of measuring the flow rate of a fluid to be detected with high accuracy when tap water is used as the fluid to be detected.

Means for Solving the Problems In order to solve the above problems, the flow rate detection device of the present invention has a spiral chamber whose horizontal cross section is circular, and a transparent sensor having a fluid inlet in the tangential direction of the outer circumference of the spiral chamber. a spiral case, a fluid outlet provided vertically in the center of the bottom of the spiral case, a sphere provided in the spiral chamber and orbiting together with the fluid, and an orbit of the sphere sandwiching the spiral case. a light emitting means and a light receiving means disposed at a position where the optical path is blocked by the spiral case, the light emitting means,
It consists of a light-shielding cover that covers the light-receiving means, and the flow rate of the fluid is detected based on the output signal from the light-receiving element.

Effect With the above configuration, when fluid flows into the swirl chamber, the sphere provided in the swirl chamber revolves around the swirl chamber.

Depending on the position of the rotating ball, the light-emitting element and light-receiving element placed between the spiral case may receive light from the light-emitting element, or the rotating sphere may block the light.
If no light is received, the flow rate of the fluid, which is proportional to the rotational speed of the sphere, is detected from the pulse signals output from these light receiving elements and representing the rotational speed of the sphere.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

FIG. 1 is a horizontal sectional view showing this embodiment, and FIG. 2 is a vertical sectional view seen from the lateral direction.

The inlet 17 into which the fluid to be detected flows is connected from the tangential direction of the outer circumference of the swirl chamber 18tL in the transparent swirl case 18, where the fluid to be detected flows in from the inlet 17 and a vortex is generated, and the swirl chamber 182L. .

Further, an outlet 19 through which the fluid to be detected flows out from the swirl chamber 182L is provided in a direction perpendicular to the center of the bottom surface of the swirl chamber 18&. A rotating ball 20 as a sphere is provided inside the swirl chamber 18& in the swirl case 18, and is rotated by the vortex flow of the fluid to be detected. rotating ball 2o
The material is a resin such as polysulfone, and it is black to prevent light reflection. Note that the spiral case 18 is provided with a protrusion 18b for stably rotating the rotating ball 20. On the outer side wall of the spiral case 18 around which the rotating ball 20 revolves, there are light emitting elements 2 that face each other with the spiral case in between.
1 and a light receiving element 22 are arranged.

As shown in FIG. 2, the centers of the optical axes of the light emitting element 21 and the light receiving element 22 are at the same height h from the bottom surface, and are also at the same position as the center of the orbit where the rotating ball 2o revolves around the spiral chamber 181L. be. Further, as shown in FIG. 1, the light emitting element 21 and the light receiving element 22 are arranged at different distances from the center line 23. That is, the distance from the center line 23 to the light emitting element 21 is 21, and the distance to the light receiving element 22 is β.
2, El>12. For example, in the experiment, E
1=8 range, 12-=4.5 range.

24 is a light shielding cover, which includes a light emitting element 21 and a light receiving element 22.
By covering the spiral case 18, disturbance light is blocked and the influence of the disturbance light is prevented.

It is also black to prevent light from reflecting inside.

FIG. 3 shows a control circuit that converts the rotational speed of the rotating ball 2o into a pulse signal. 25, 26.

27 is a resistor, and 28 is an NPN) transistor.

Next, the operation of the above configuration will be explained with reference to FIGS. 1 to 4. When fluid flows into the swirl chamber 181L from the direction of arrow H, the fluid swirls in the swirl chamber 18fL, and accordingly, the rotating ball 20 also moves into the swirl chamber 1B+! Rotate around while pressing the inner wall of L.

This rotating ball 2o has a characteristic of rotating in proportion to the flow rate of the fluid. Therefore, in order to measure the flow rate, it is sufficient to measure the number of rotations of the rotating ball 20 that rotates in proportion to the flow rate.

In this embodiment, by arranging the light emitting element 21 and the light receiving element 22 at opposing positions with the spiral case 18 in between, when the rotating ball 20 rotates, the rotating ball blocks the light emitted from the light emitting element; The difference in the current flowing through the light receiving element when the light is transmitted is converted into a pulse by the control circuit, which is used as a flow rate signal. In other words, when the rotating ball 2° is in the position of the person shown in Fig. 1, the light receiving element 22
A current flows through the NPN) transistor 28 at 70m, and the voltage of the NPN) transistor 28 is approximately 0.2 V.
An H1 signal is generated at F L and output 29. On the other hand, when the rotating ball 20 is at position B, no current flows through the light receiving element 22, and the pace potential of the NPN transistor 28 becomes high, causing an OW state and output 29 to generate a signal.

Therefore, when the flow rate is high, the signal output from the output 29 has a short cycle as shown in Figure 4 (&), and when the flow rate is low, the signal output from the output 29 has a short cycle as shown in Figure 4 (b). ), the period becomes longer. The flow rate can be detected by inputting the signal output from the output 29 to the microcomputer 3o. Since the swirl chamber 181L has a circular shape, resistance to fluid flow is small even though it has the rotating ball 2o. Furthermore, since the center of the orbit of the rotating ball 20 around the spiral chamber 181L is the same as the center of the optical axis of the light emitting element 21 and the light receiving element 22, even if scale is about to adhere, the rotating ball 20 will not scrape it off. Therefore, even after long-term use, the phenomenon of deterioration of light transmission is less likely to occur. In addition, since the surface of the rotating ball 20 and the light-shielding cover 24 that covers the spiral chamber 18&, the light emitting element 21, and the light receiving element 22 are made of black, there is less reflection of light and it is less susceptible to the influence of light from the outside. There is a clear distinction between light transmission and light blocking, and the signal indicating the flow rate outputted from the output 29 can also be input as a clear pulse signal to the control unit 3° such as a microcomputer. Furthermore, by providing the protrusion 18b on the upper part of the spiral case 18, the sphere more stably orbits in the same orbit, and a stable pulse signal can be obtained.

In this embodiment, the light emitting element and the light receiving element are arranged horizontally, but if the optical path of the light emitting element and the light receiving element can be blocked on the orbit of the rotating ball, the light emitting element and the light receiving element can be arranged horizontally. may be arranged diagonally or vertically.

Further, in this embodiment, the spiral case is arranged horizontally, but the same effect can be obtained even if it is arranged vertically.

Effects of the Invention As is clear from the description of the embodiments above, the flow rate detection device of the present invention has the following effects.

Since the area in which water contacts the walls of the swirl chamber is small, resistance to fluid flow is also small. In addition, since the resistance to the fluid is small, scale is less likely to adhere due to the rotation of the sphere, and the amount of light transmitted does not decrease even after long-term use, allowing accurate flow rate detection.

[Brief explanation of the drawing]

Fig. 1 is a horizontal sectional view showing an embodiment of the flow rate detection device of the present invention, Fig. 2 is a vertical sectional view of the device, Fig. 3 is a control circuit diagram of the device, and Fig. 4 is a light receiving device of the device. 6 and 6, which show the waveform of the output signal of the element, are a horizontal cross-sectional view and a vertical cross-sectional view, respectively, of a conventional flow rate detection device. 17... Inlet, 18... Spiral case, 18 &... Spiral chamber, 19... Outlet, 2o... Rotating ball ( sphere), 21...
... Light emitting element, 22 ... Light receiving element, 24.
・・・・・・Blackout cover. Name of agent: Patent attorney Toshio Nakao and 1 other person17
---Asahachi 3---Case with overline 20--Ichiromura bowl 21--Light-emitting element section Dimensions Section Section Section Ri section Section

Claims (3)

[Claims] (1) A transparent spiral case that has a spiral chamber with a circular horizontal cross section and a fluid inlet in the direction tangential to the outer circumference of the spiral chamber, and a transparent spiral case that is installed vertically at the center of the bottom of the spiral case. a fluid outlet, a sphere provided in the spiral chamber and orbiting together with the fluid, and a light emitting means and a light receiving means disposed at positions sandwiching the spiral case and having an optical path blocked by the orbit of the sphere; the spiral case;
A flow rate detection device that includes a light-emitting device and a light-shielding cover that covers a light-receiving device, and detects a fluid flow rate based on an output signal from the light-receiving element. (2) The flow rate detection device according to claim 1, wherein the outer surface of the sphere and the inner surface of the light shielding cover are blackish. (3) The flow rate detection device according to claim 1, wherein a conical projection projecting downward is provided at the center of the ceiling of the spiral case.