JP2005077402A - Flow sensor and flow rate measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow sensor and a flow rate measuring device capable of measuring the flow rate accurately even when a pulsating flow or a back flow exists. <P>SOLUTION: In this flow sensor, a rotating body having a portion reflecting light is provided rotatably by fluid on a prescribed position in a fluid passage, and a light emission part for emitting light toward the portion reflecting light is provided, and two light receiving parts are arranged on a position capable of receiving reflected light from the portion reflecting light of the light, in parallel in the rotation direction of the rotating body. This flow rate measuring device is equipped with the flow sensor and a flowmeter connected to the light receiving parts, for measuring the flow rate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Detailed Description of the Invention

  The present invention relates to a flow rate sensor and a flow rate measuring apparatus that can correctly measure a flow rate even when there is a pulsating flow or a reverse flow. It is to be disclosed.

  As a means for measuring the flow rate of a fluid such as gas or liquid, for example, a blood pump uses an electromagnetic flow meter that magnetizes blood flow with a magnet and measures this with a magnetic sensor. For example, a vortex is used with a gas flow meter. Vortex flowmeters have been used that measure Karman vortices generated behind generators with ultrasonic transducers.

Problems to be solved by the invention

  However, a pulsating flow or a back flow may occur regardless of whether the blood flow or the gas flow, and this may cause an overcount in the flow rate measurement, and may cause an error of up to 15 percent.

  Accordingly, an object of the present invention is to provide a flow rate sensor and a flow rate measuring device that can correctly measure the flow rate even when there is a pulsating flow or a reverse flow. In the above, an example of measuring the blood flow rate has been given. However, the present invention also has an object to provide a flow rate sensor and a flow rate measuring device capable of correctly measuring the urine velocity during urine collection.

Means and action for solving the problem

  The above problem is that a rotating body having a part that reflects light is provided at a predetermined position in the fluid passage so as to be rotatable by a fluid, and a light emitting unit that emits light toward the part that reflects light is provided. This is achieved by providing a flow rate sensor in which two light receiving portions are arranged side by side in the rotational direction of the rotating body at a position where it can receive reflected light from a portion that reflects the light.

  Since a rotating body is provided in the fluid passage, when the fluid passes through the fluid passage, the rotating body rotates with that momentum. At this time, since the rotating body is provided with a part that reflects or does not reflect light, the light emitted from the light emitting part can be reflected by the part that reflects the light and reach the light receiving part. Since it does not reflect in the part which does not reflect, it cannot reach a light-receiving part. Accordingly, if a rotating body designed by calculating how light emitted from the light emitting part is reflected is used, the speed of the fluid rotating the rotating body can be obtained.

  Further, at this time, since the two light receiving portions are arranged side by side in the rotation direction of the rotating body, by looking at the order in which the two light receiving portions receive light, that is, by examining the order in which the rotating body reflects the light, The direction in which the fluid flows can be detected. Therefore, it is possible to accurately grasp this state even when there is a reverse flow or pulsating flow with respect to the normal flow. Although two light receiving parts are used, the number of light receiving parts may be two or more as long as the circuit can be used.

  In addition to the invention of claim 1, in the invention of claim 2, the part that reflects light is a mirror surface. The light emitted from the light emitting part is reflected by the part that reflects the light and reciprocates in the fluid until it reaches the light receiving part. When the fluid is blood, urine or the like, the light is attenuated. Therefore, it is desirable that the portion that reflects the light has a high reflectance such as white. In particular, a mirror surface is better.

  The rotating body is assumed to be an impeller. Light passes through the space between the wings of the impeller, and the light emitted from the light emitting unit does not reach the light receiving unit, but the reflected light reflects the light at the wing part. Reaches the light receiving part. The number of wings is arbitrary, but it is easier to design if they are rotationally symmetrical.

  Further, a light emitting diode or a laser diode can be used for the light emitting portion. These elements are easy to handle. What is necessary is just to provide the light-receiving part corresponding to these light emission sources. Moreover, it is possible to select a light emitting unit that emits infrared rays, and measurement with good efficiency and accuracy can be performed.

  The flow rate measuring device may be formed by masking the inside thereof so as not to transmit ambient light. If the ambient light is blocked by the mask, the light receiving part can receive only the light from the light emitting part, and for example, an accurate measurement that is not bothered by the environmental light such as flicker of fluorescent lamps becomes possible.

  A urine collection tube may be connected to the fluid passage. By adopting such a configuration, the trouble of connecting or disconnecting the flow sensor to the tube can be saved. Moreover, it will open the way to the disposable use of the flow sensor in the sense of eliminating unsanitary handling and preventing infection. In addition, since the said flow sensor is not used only for urine collection, it is good also as what connected the tube according to the use. It can be attached to tubes with different diameters, branching tubes, and the like.

  Next, in the invention according to claim 9, the flow rate measuring device including the flow rate sensor and the flow meter connected to the light receiving unit to measure the flow rate is attached to each of the flow rate sensors of claims 1 to 8. Yes.

  The above-described flow rate sensor can perform actual flow rate measurement by connecting the output end of the light receiving unit to the input end of the flow meter. In the present invention, the flow sensor includes a flow meter, and the flow rate can be measured only with this configuration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments, and various variations are given within the scope of the idea of the present invention. Is something you can do.
(First embodiment)

  1 to 3 show a first embodiment of the present invention. In the case 1 made of synthetic resin, a substantially circular recess 11 for accommodating the disc 2 is formed in the center, and the disc 2 is rotatably mounted in the recess 11 by a rotating shaft 20. In addition, an inlet 10 and an outlet 12 are formed in a portion of the case 1 that is shifted to one side from the rotating shaft 20, and forms a water flow path that continues from the inlet 10, the recess 11, and the outlet 12. The disk 2 is a white synthetic resin disk and its surface reflects light well, but twelve windows 21 penetrate the disk 2 in a rotationally symmetrical manner on the outer periphery. It is formed as follows. A light receiving element 3 and a light emitting element 4 are disposed on one side of the case 1 so as to face the rotating portion of the window 21 of the disk 2. In FIG. 1, the mounting position of the light receiving element 3 is shown. The light receiving element 3 includes two series of photodiodes, and a first element 30 and a second element 31 are attached so as to be aligned in the rotation direction of the disk 2. The light emitting element 4 is an LED (Light Emitted Diode).

  Now, the light emitted from the light emitting element 4 is reflected by the surface of the white disk 2 between the windows 21 and enters the light receiving element 3. On the other hand, at the site of the window 21, light passes through the disk 2 through the window 21, and therefore does not enter the light receiving element 3. Therefore, since the light receiving element 3 generates a signal in accordance with the operation of the disk 2, this waveform is transformed into a beautiful waveform that can be counted by the encoder 50, counted by the reversible counter 5, and this number is displayed on the display 51. Is displayed. In this embodiment, the flow rate measuring device is constituted by the above-described flow rate sensor and the counting circuit shown in FIG. The reversible counter 5 can distinguish the rotation direction of the disk 2. The first element 30 mounted so as to be aligned in the rotation direction of the disk 2 does not receive light before the second element 31, and the second element 31 does not receive light thereafter. If this is the case, it can be seen that the case where the second element 31 does not receive light first, that is, the reverse rotation of the disk 2, so even if there is a backflow or a pulsating flow, it can be accurately handled accordingly. It can be counted.

In this embodiment, an LED that emits infrared light is used as the light emitting element 4, but an embodiment using a laser diode (Laser Diode), a filament sphere, or the like is also possible. Needless to say, the surface of the disc 2 is white, but may be a mirror surface. Since the disk 2 is designed by calculating how the light emitted from the light emitting element 4 is reflected, the number of the windows 21 is twelve, but the number is limited to this number. is not. The material is not particularly limited.
(Second Embodiment)

FIG. 4 shows a second embodiment of the present invention. The white disc 23 made of synthetic resin is rotatable by the rotary shaft 20, and a portion other than the twelve non-colored portions 24 secured in a rotationally symmetrical manner on the outer peripheral portion is a black colored portion 25. With this configuration, the light emitted from the light emitting element 4 is reflected by the non-colored portion 24, but is absorbed by the black colored portion 25 and no effective reflection occurs.
(Third embodiment)

FIG. 5 shows a third embodiment of the present invention. The black disc 22 made of synthetic resin is rotatable by the rotary shaft 20, and 12 mirrors 26 are formed on the outer peripheral portion in a rotationally symmetrical manner by aluminum vapor deposition. With this configuration, the light emitted from the light emitting element 4 is reflected at the portion of the mirror 26, but is absorbed at the black portion between the mirror 26 and the mirror 26 so that effective reflection does not occur.
(Fourth embodiment)

FIG. 6 shows a fourth embodiment of the present invention. A white disc 23 made of synthetic resin is rotatable by the rotary shaft 20, and twelve protrusions 27 are formed on the outer peripheral portion by rotationally symmetric molding. With this configuration, the light emitted from the light emitting element 4 is basically reflected on the plate surface of the white disk 23, but irregular reflection occurs particularly at the portion of the protrusion 27, so that this disturbance is captured by the counting circuit. Like that.
(Fifth embodiment)

  Next, FIGS. 7 to 9 show a fifth embodiment of the present invention. In the case 1 made of synthetic resin, a substantially circular recess 11 for accommodating the water wheel 6 is formed at the center, and the water wheel 6 is rotatably mounted in the recess 11 by a rotating shaft 60. In addition, an inlet 10 and an outlet 12 are formed at a portion of the case 1 that is shifted to the one side from the rotating shaft 60, thereby forming a water flow path that continues from the inlet 10, the recess 11, and the outlet 12. The light receiving element 3 and the light emitting element 4 are provided on one side of the case 1 and in a portion that is reflected or not reflected by the wings of the rotatable water wheel 6. In FIG. 7, the mounting position of the light receiving element 3 is shown. The light receiving element 3 is composed of two photodiodes, and a first element 30 and a second element 31 are attached so as to be aligned in the rotation direction of the water wheel 6. The light emitting element 4 is an LED (Light Emitted Diode).

FIG. 8 shows the relationship among the water wheel 6, the light emitting element 4, and the light receiving element 3. The light emitting element 4 and the light receiving element 3 are disposed on one side of the water wheel 6 that is rotatable by the rotation shaft 60 to constitute a flow rate sensor. The positional relationship between the light emitting element 4 and the light receiving element 3 is such that the light emitted from the light emitting element 4 enters the light receiving element 3 when reflected by the water wheel 6, as in the above-described embodiments. Since the light receiving element 3 generates a signal in accordance with the operation of the water turbine 6, the waveform is transformed into a beautiful waveform that can be counted by the encoder 50, counted by the reversible counter 5, and displayed on the display 51. To do. Therefore, a flow rate measuring device is constituted by the flow rate sensor of this embodiment and the counting circuit shown in FIG. The reversible counter 5 can distinguish the rotation direction of the water wheel 6 (which is an impeller). The case where the first element 30 stops receiving light before the second element 31 ((a) in FIG. 4), and then the second element 31 stops receiving light ((b) in FIG. 4) If it is normal rotation, it turns out that the case where the 2nd element 31 stops receiving light first is reverse rotation of the water turbine 2. For this reason, even if there is a backflow or a pulsating flow, it can be accurately counted.
(Sixth embodiment)

  FIG. 10 shows a sixth embodiment of the present invention. When an error occurs in the counting operation due to fluctuations in ambient light such as a fluorescent lamp, and this becomes a problem, at least a pair of the light emitting element 4 and the light receiving element 3 in the case 1 is connected as in the flow sensor shown in FIG. It is better to mask only a certain peripheral portion by coloring it black. Reference numeral 7 denotes a mask, which forms a window 70 having no color only in a portion where the light receiving element 3 is present. In FIG. 10, the pair of the light emitting element 4 and the light receiving element 3 exists behind the window 70.

Coloring is not limited to black, and any color can be used as long as it can block ambient light. The entire case 1 may be colored. In addition to applying the color to the case 1, the coloring can be formed by polymerizing a separate colored plate or making the material of the case 1 opaque. In this case, it is necessary to make only the portion of the window 70 a transparent member.
(Seventh embodiment)

  FIG. 11 shows a seventh embodiment of the present invention. The flow rate sensor of this embodiment is characterized in that a urine collection tube 92 is attached to the inlet 10 of the case 1 and a connector 9 is attached to the outlet 12. The detector 8 is detachably attached to the case 1 so that the flow sensor with the tube 92 is disposable. Reference numeral 80 denotes a cable for connecting the output end of the light receiving element 3 and the input end of the light emitting element 4 to the flow measuring device.

That is, a U-shaped detector 8 that can sandwich the case 1 is detachably attached to the case 1 by a guide 13 provided on one side of the case 1. On one side of the detector 8, a pair (not shown) of the light emitting element and the light receiving element described above is provided. Further, a cable 80 relating to the light emitting element and the light receiving element is drawn from the detector 8. A connector 91 is attached to the distal end portion of the tube 92, and the tube 92 is inserted into the inlet 10 of the case 1 through the connector 91. A connector 9 is inserted into the outlet 12 of the case 1. A handle 90 is attached between the connector 9 and the case 1 so that the connector 9 can be handled easily.
(Other)

  The flow rate measuring device can be configured by combining the flow rate sensors of the second to fourth and sixth embodiments described above and the counting circuit shown in FIG. 3, for example. In addition, it is possible to provide an embodiment suitable not only for measuring liquid such as urine flow and blood flow, but also for measuring gas such as gas. The configuration, shape, and size of the rotating body are optional design items. In addition, the rotating body has a rotating shaft, and a mechanism that fits into a groove that can support the rotating shaft, a mechanism that rotates while the rotating body floats using the repulsive force of the magnet, etc. are arbitrarily adopted. It is possible. As the light emitting portion, either a constant light emission or a light emission appropriately modulated can be used as long as it corresponds to the circuit. Therefore, it is possible to arbitrarily design the counting circuit.

The invention's effect

  As described above, according to the present invention, a rotating body having a part that reflects light is provided at a predetermined position in the fluid passage so as to be rotatable by a fluid, and a light emitting unit that emits light toward the part that reflects light is provided. At the same time, the flow rate sensor is formed by arranging two light receiving portions side by side in the rotational direction of the rotating body at a position where the reflected light from the portion that reflects the light can be received. Moreover, it is set as the flow volume measuring apparatus provided with this flow sensor and the flowmeter connected to this light-receiving part, and measuring a flow volume.

  As a result, the present inventors have succeeded in providing a flow rate sensor and a flow rate measuring device that can correctly measure the flow rate even when there is a pulsating flow or a reverse flow, and often achieve the intended purpose.

It is a top view of a 1st embodiment. It is a schematic diagram of the same embodiment. It is a block diagram of the embodiment. It is a top view of a 2nd embodiment. It is a top view of a 3rd embodiment. It is a top view of a 4th embodiment. It is a top view of a 5th embodiment. It is a schematic diagram of the same embodiment. It is operation | movement explanatory drawing of the embodiment. It is a top view of a 6th embodiment. It is a side view of 7th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 10 Entrance 11 Recess 12 Exit 13 Guide 2 Disk 20 Rotating shaft 21 Window 22 Black disk 23 White disk 24 Non-colored part 25 Colored part 26 Mirror 27 Protrusion 3 Light receiving element 30 First element 31 Second element 4 Light emission Element 5 Reversible counter 50 Encoder 51 Display 6 Water wheel 60 Rotating shaft 7 Mask 70 Window 8 Detector 80 Cable 9 Connector 90 Handle 91 Connector 92 Tube

Claims (9)

  A rotating body having a portion that reflects light is provided at a predetermined position in the fluid passage so as to be rotatable by a fluid, and a light emitting unit that emits light toward the portion that reflects light is provided. A flow rate sensor characterized in that two light receiving portions are arranged side by side in the rotational direction of the rotating body at a position where it can receive reflected light from a portion that reflects light.   The flow sensor according to claim 1, wherein the portion that reflects the light is a mirror surface.   The flow sensor according to claim 1, wherein the rotating body is an impeller.   The flow sensor according to claim 1, wherein the light emitting unit is a light emitting diode.   The flow sensor according to claim 1, wherein the light emitting unit is a laser diode.   The flow sensor according to claim 1, wherein the light emitting unit emits infrared light.   The flow sensor according to claim 1, wherein the flow meter is masked so as not to transmit ambient light.   The flow sensor according to claim 1, wherein a urine collection tube is connected to the fluid passage.   A flow rate measuring device comprising: the flow rate sensor according to any one of claims 1 to 8; and a flow meter connected to the light receiving unit to measure a flow rate.

Images