JPH02291922A - Flow-rate detector - Google Patents

Abstract

PURPOSE:To make it possible to maintain the highly accurate detecting capability for the flow rate of solvent and paint when the flow rate is small for a long period by providing casings having acid and solvent resisting characteristics and a closely sealed annular path in a closed circuit pattern in the inside. CONSTITUTION:A sealing material is held between stainless casings 1a and 1b. A closely sealed annular path 2 having the circular cross section is formed along the entire inner surface. A plurality of spherical bodies 5 whose outer surfaces keep slight gaps so that the bodies can be rolled and slidden in the path are inserted in the annular path. Said spherical body has a high hardness. An inlet port 3 and an outlet port 4 for fluid are opened at the appropriate positions of the annular path. A movement detecting system for the spherical body 5 is provided at the side wall of the annular path between the inlet port 3 and the outlet port 4. The fluid passes through a part of the path 2. The spherical body 5 moves from the inlet port 3 of the fluid to the outlet port 4 following the flow of the fluid. The spherical body is separated from the flow of the fluid in the vicinity of the outlet port 4 and recovered. When the spherical body is recovered, a spherical body 5c which is standing by at the inlet port 3 is thrown into the flow of the fluid. The spherical body 5c enters into the annular path. The flow rate is measured based on the moving speed of the spherical body 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention measures the amount of transferred fluid in general, and is particularly used in the field of high-grade painting, which requires highly accurate control of the flow rate of paint at a relatively small flow rate. It is useful in

Problems to be Solved by Conventional Technology First, there are two types of liquid flowmeters: a mechanical type that has a mechanically moving part in the flow rate detection section, and a non-mechanical type that does not have a mechanically moving part. .

As a mechanical method, a volumetric measuring method using an oval gear mechanism or the like is well known. The kinetic energy of the fluid is converted into the rotational speed of the support shaft by the meshing of the gears, and the flow rate is measured from the relationship between the discharge amount of the oval gear mechanism and the rotational speed of the support shaft. Since the liquid passes through the chamber by continuous movement, it is possible to accurately measure minute flow rates, but there are many mechanical parts that mesh with each other, making them susceptible to wear and tear. Furthermore, if the movement of mechanical parts is obstructed by foreign matter entering, the differential pressure in the volumetric part becomes large, and if the fluid pressure is high, there is an even greater risk of damage to the mechanical parts.

In particular, when used for high-grade coatings, there were even more serious defects. Of course, when dealing with paints that contain strong organic solvents such as MEK and highly hard colored pigments, it must be constructed with solvent-resistant parts, but the most suitable flowmeter is This is a defect in which when handling fluids are used to lubricate mechanical parts, pigments accelerate wear and make them unusable early. Furthermore, in order for metallic paints mainly made of aluminum contained in metallic paints to develop properly,
It is desirable for the metallic flakes to have a needle-like shape that easily reflects light during compounding, but when passed through a gear-type mechanical flowmeter, the metallic flakes are bent or broken at the meshing part of the gear, causing the metallic paint to develop color. The flow meter could not be used for metallic paint due to a defect that adversely affected the paint. In addition, the influence of pressure loss due to the movement of mechanical parts has a disadvantage in that it also adversely affects the atomization of paint in the spray head.

Next, non-mechanical flowmeters (generally known are Coriolis, ultrasonic Doppler effect method, differential pressure detection method, temperature difference detection method, eddy current detection method, etc.). Since there are no parts, it has excellent durability, but it is expensive and has poor measurement accuracy, so it cannot be used for highly accurate flow control of small flow rate paints.The composition and viscosity are different, and it is a non-Newtonian fluid. Mechanical volumetric flowmeters, which have many problems, were the only way to measure certain coatings with high precision without being affected by environmental changes.

Problem to be Solved by the Invention In a mechanical volumetric flow meter used for highly accurate flow control of paint, it is possible to detect the flow rate of solvents and paint with high precision, especially in the case of small flow rates, for example, flow rates of 11 or less per minute. Overcoming wear resistance and solvent resistance that cannot be maintained over a long period of time. Also, when handling metallic paints, countermeasures against adverse effects on color development during painting due to damage to metallic flakes. Also, prevents damage to mechanical components caused by dust etc.

Improving pressure resistance, reducing pressure loss, and reducing manufacturing costs are urgent issues.

Means for Solving the Problems: A robust casing which has acid and solvent resistance properties, has a sealed annular passage with a closed circuit inside, and has a surface treated with high hardness on the surface of the annular passage, and the annular 3!1 A plurality of high-hardness spheres are inserted substantially inside the passageway so that the outer periphery can move and slide with the inner periphery of the passage with a slight gap, and the above-mentioned system is provided.

Functions and Effects of the Invention The present invention has the above-mentioned configuration, in which liquid passes through a portion of the sealed annular passage, and according to the flow, the sphere moves from the inlet to the outlet of the liquid, and near the outlet. Separated and recovered from the liquid stream. In order to be able to throw the spheres waiting at the inlet during collection into the liquid flow, we decided to use the annular passage as a circulation passage for the spheres and calculate the flow rate from the moving speed of the spheres. (a) Simple structure, no mechanical connection, no driving force τ,
There will be no accidents resulting in damage to mechanical parts. In addition, wear resistance can be improved simply by increasing the hardness of a portion of the liner of the annular passage and the surface of the sphere.
Improved pressure resistance performance, applicable to flow rate measurement of all fluids.

mouth. There are no mechanical elements that mesh at acute angles, and there is no damaging force9 caused by the metallic flakes of metallic paint.
There is no negative effect on the color development of metallic paint, and it can also be used to measure the flow rate of metallic paint.

C. There is almost no pressure difference between the front and rear of the sphere), so by reducing the gap between the annular passage and the sphere, leakage of fluid between the front and rear of the sphere is minimized, and there is no discrepancy in the amount of movement between the liquid and one sphere. Therefore, the moving speed of the liquid can be detected with high precision. Moreover, since there is little frictional resistance, pressure loss can be kept low.

From the above point of view, the present invention attempts to obtain a high-precision flow meter for paints, etc., which can handle small flow rates.

Example The operation will be explained below based on specific examples.

FIG. 1 is a longitudinal sectional view of the flow meter main body of this embodiment, and FIG. 2 is a longitudinal sectional view taken along the line AA' in FIG. The installation status of this device is
The ball reservoir should be at the bottom to allow the ball to be fed out using gravity.

(la) and (lb) are stainless steel casings containing no magnetic material, and between the casings, an inlet (3) and an outlet (4) are opened to the sealed annular passage 2, A fluid path (not shown) is connected to each of them.
), a plurality of spheres 5 made of a material containing a magnetic substance and built in are slidable in the passageway and provided with an appropriate gap for fluid sealing. In Figure 1, (5
a) shows the sphere passing through the fluid movement area at the top of the channel 2; In this state, the inlet (3),
? Both A outlets (4) are open, and the sphere (5a) is carried toward the outlet by [fluid pressure on the outlet side <[fluid pressure on the inlet side]].

In the passage of the sphere waiting area corresponding to the lower part of the passage (2), in order to create a waiting state so that the spheres (5) are sequentially discharged from the inflow port (3) into the flow passage while maintaining close intervals between each sphere. A mechanism for pushing out the spheres (5) sequentially from the outlet (4) into the channel will now be described.

In Figure 1, the sphere (5a) is moving toward the outlet.
The state in which the sphere reaches the outlet and contacts the last waiting sphere (5b) is indicated by a two-dot chain line (5a'). The liquid filling between the spheres is discharged through the communication groove (6), and the distance between the spheres becomes tight. At this time, since the entire sphere (5) is placed under hydrostatic pressure, the position of the sphere within the passage moves in a direction that is balanced left and right. Due to this movement, the foremost sphere (5c) waiting at the inlet becomes j(
It will be pushed up to the 5 (!') position. At the position (5c), the proboscis is in a position to block the inlet (3), and due to the difference in fluid pressure between the inlet and the outlet, (5 c') -
(5 a) It is fed out in the direction.

Next, sphere movement detection and flow rate conversion will be explained.

In order to detect the movement of the magnetic body, a magnetic proximity sensor (not shown) was placed between the inlet and outlet in FIG. 1 so as to be able to detect the passage of the sphere.

The sensor 7 is for resetting the output value, and is used when a moving sphere is located between the magnetic proximity sensor (8) and the magnetic proximity sensor (9) when the fluid flow stops. This is a consideration for canceling the first detection signal in the magnetic proximity sensor (9) when the fluid begins to flow and not outputting a defective value.

The method of converting the flow rate is that when the passage of the sphere is confirmed by the proximity sensor (8), time measurement is started, and when the arrival of the sphere is confirmed by the proximity sensor (9), the time measurement is completed and the time elapsed is until(T). ) is understood. In the next arithmetic processing circuit, since the passage cross-sectional area (S) and the distance between the sensors gl (Ll are constant, S*L/T is used to calculate and output the appropriate flow rate per unit time.Quantity of sensors increase,
Detection cycles and responsiveness will further improve as the sensor's detection sensitivity improves.

As specifically explained in the above embodiments, the flow rate detection device of the present invention has a casing in which an annular passage with a circular cross-section is formed and is placed vertically, and the inlet and outlet of the fluid are provided at appropriate positions. The annular passage has a structure in which a plurality of spheres are built into the annular passage so as to be tightly and slidably connected to the passage wall surface, and the spheres circulate through the annular passage as the fluid moves, so that the spheres can move at the same speed as the fluid, Since the system is designed to collect and recirculate, the gist of the system is to be able to continuously measure the flow rate of fluid by measuring the movement of the sphere. Simple structure eliminates mechanical coupling and driving parts. Applicable to all fluids, highly durable and adaptable.

B. Since it does not damage metallic flakes, it can be used in metallic paints.

C. The discrepancy between the moving speed of the fluid and the moving speed of the sphere becomes extremely small, resulting in effects such as enabling highly accurate flow rate measurement with low pressure loss.

In other words, it enables a flow rate measurement device that has the durability and adaptability of conventional non-contact type flow rate measurement devices, and also has the features of high-precision metering that are more advanced than mechanical methods. . In this embodiment, a magnetic proximity sensor is used as the sphere detection sensor, but a Hall element sensor may also be used. Alternatively, the shape of the annular passage may be devised to make the measurement portion a long straight line, and the speed may be detected by the de Sobler effect using ultrasonic waves. In addition, in this example, the casing was made strong for high-pressure fluid, but if the casing is made of wood or the sphere is made of resin material containing magnetic material, it can be made lightweight. It can also be used as a pressure fluid and gas flow rate detector.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of this embodiment. Figure 2 is Figure 1 A-A'
Line longitudinal cross-sectional view. FIG. 3 is a view of the main body of the flowmeter, cut along the line 0-0' of FIG. 1 and developed horizontally for convenience. 1
Casing, 2... Annular passage, 6 Communication groove, 7, 8,
9. Magnetic proximity sensor 10. Signal processing circuit.

Claims (1)

[Claims] 1. A closed-circuit sealed hollow passage is formed in the casing, a plurality of sliders are inserted into the passage and are capable of sliding while maintaining an appropriate gap with the passage wall surface, and an opening is formed in the passage. In the passage filled with fluid, the slider is inserted near the fluid inlet opening into the passage, and the slider is slid along the flow of the fluid flowing toward the outlet. A circulation path for the slider is constructed in which the slider is moved, the slider is collected near the fluid outlet, and is placed on standby so that it can be introduced into the fluid inlet again. A fluid flow rate detection device characterized by comprising means for detecting the slider and outputting a signal. 2. The flow rate detection device according to claim 1, comprising a signal processing section that is capable of recognizing the flow rate per unit time by signal processing the detection signal output by the detection body.