JP2021183953A - Flow sensor device - Google Patents

Abstract

To provide a flow sensor device that enables a simple structure to detect a wind direction and wind speed.SOLUTION: A flow sensor device (1) has: a substrate (2); and sensor elements (3, 4 and 5) that are provided with a plurality of temperature sensing resistance elements arranged in the substrate. Each sensor element is arranged in a mutually oblique way in a plane view of the substrate. According to the present invention, the sensor element is preferable to have three sensor elements provided, and to be arranged so as to be an equilateral triangle in the plane view thereof.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a flow rate sensor device capable of measuring a wind direction.

A thermal flow rate sensor device is known that exposes a heated resistance element for flow rate detection to a fluid and detects the flow rate of the fluid based on the heat dissipation action at that time. For example, Patent Document 1 discloses an invention relating to a wind direction anemometer having a spherical structure and arranging a plurality of linear detection portions in the meridian direction and the latitude line direction in the structure.

Japanese Unexamined Patent Publication No. 2011-2315

However, in the configuration of Patent Document 1, a spherical structure must be manufactured with high accuracy, and moreover, a plurality of detection units are arranged in the meridian direction and the latitude line direction on the surface of the structure, and the detection units are arranged with each other. It is necessary to provide an insulating part at the intersection of the two to electrically insulate. As described above, in Patent Document 1, the structure is considerably complicated, and a plurality of detection portions must be laid along the surface of the sphere in the meridian direction and the latitude line direction, resulting in poor productivity.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a flow rate sensor device capable of detecting a wind direction and a wind speed with a simple structure.

The flow sensor device in the present invention includes a substrate and a sensor element provided with a plurality of temperature-sensitive resistance elements arranged on the substrate, and each sensor element is tilted obliquely with respect to each other in a plan view of the substrate. It is characterized by being arranged in a row.

The flow sensor device of the present invention has a structure in which a plurality of sensor elements are diagonally arranged on a substrate in a plan view, and a simple structure can be obtained by comparing wind speed information acquired by each sensor element. , It becomes possible to detect the wind direction and the wind speed at the same time.

It is a perspective view of the flow rate sensor device in this embodiment. It is a top view of the flow rate sensor device in this embodiment. It is sectional drawing of the sensor element of this embodiment. It is a circuit diagram of the flow rate sensor device of this embodiment. It is a graph which shows the directivity measurement result of the flow rate sensor device. It is a graph which shows the output voltage of three sensor elements mounted on the flow rate sensor device of this embodiment. It is a conceptual diagram for demonstrating the relationship with the wind direction with respect to each sensor element when three sensor elements arranged in an equilateral triangle are rotated by 30 degrees.

Hereinafter, an embodiment of the present invention (hereinafter, abbreviated as “embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

FIG. 1 is a perspective view of the flow rate sensor device of the present embodiment. FIG. 2 is a plan view of the flow rate sensor device according to the present embodiment.

The X and Y directions shown in FIGS. 1 and 2 indicate two directions orthogonal to each other in the plane, and the Z direction indicates a height direction orthogonal to each other in the X and Y directions.

The flow rate sensor device 1 of the present embodiment shown in FIG. 1 includes a substrate 2 and a plurality of sensor elements 3, 4, and 5.

The substrate 2 is an insulating substrate, and is not particularly limited, but is preferably a general printed circuit board in which a glass cloth is impregnated with an epoxy resin, and for example, an FR4 substrate can be presented.

As shown in FIG. 1, the sensor elements 3, 4, and 5 are arranged apart from each other in the vertical direction (height direction; Z direction) of the surface 2a of the substrate 2 via the lead wire 7, respectively.

The structure of the sensor elements 3, 4, and 5 will be described with reference to FIG. As shown in FIG. 3, the sensor elements 3, 4, and 5 cover the temperature-sensitive resistance element 10, the electrode caps 11 arranged on both sides of the temperature-sensitive resistance element 10, and the temperature-sensitive resistance element 10 and the electrode cap 11. It is configured to have an insulating film 12 and the like. Then, lead wires 7 and 8 extend from the electrode cap 11 to the outside on both sides of the sensor elements 3 and 4.

The temperature-sensitive resistance element 10 shown in FIG. 3 is formed by forming a resistance film on the surface of a cylindrical substrate such as ceramic. Although not shown, the surface of the resistance film of the temperature-sensitive resistance element 10 is trimmed to adjust the resistance.

As shown in FIG. 3, the temperature-sensitive resistance element 10 is formed long in one direction. Therefore, the sensor elements 3, 4, and 5 including the temperature-sensitive resistance element 10 also have a long shape in one direction. Here, "long in one direction" means a state longer than the length in any direction orthogonal to one direction.

Hereinafter, the sensor element 3 will be described as the first sensor element 3, the sensor element 4 as the second sensor element 4, and the sensor element 5 as the third sensor element 5.

The first sensor element 3, the second sensor element 4, and the third sensor element 5 all include a temperature-sensitive resistance element (flow rate detection resistance element) 10.

The temperature-sensitive resistance element 10 constitutes the circuit shown in FIG. 4 together with the temperature compensation resistance element 14. The circuit shown in FIG. 4 is incorporated in each of the temperature-sensitive resistance elements 10 of the sensor elements 3, 4, and 5. As shown in FIG. 4, the temperature-sensitive resistance element 10, the temperature-compensating resistance element 14, and the resistors 16 and 17 constitute a bridge circuit 18. As shown in FIG. 4, the temperature-sensitive resistance element 10 and the resistor 16 form a first series circuit 19, and the temperature compensation resistance element 14 and the resistor 17 form a second series circuit 20. There is. Then, the first series circuit 19 and the second series circuit 20 are connected in parallel to form the bridge circuit 18.

As shown in FIG. 4, the output unit 21 of the first series circuit 19 and the output unit 22 of the second series circuit 20 are connected to the differential amplifier (amplifier) 23, respectively. A feedback circuit 24 including a differential amplifier 23 is connected to the bridge circuit 18. The feedback circuit 24 includes a transistor (not shown) and the like.

The resistors 16 and 17 have a smaller temperature coefficient of resistance (TCR) than the temperature-sensitive resistance element 10 and the temperature compensation resistance element 14. The temperature-sensitive resistance element 10 has a predetermined resistance value Rs1 in a heated state controlled to be higher than a predetermined ambient temperature by a predetermined value, and the temperature compensation resistance element 14 has, for example, a temperature compensation resistance element 14. It is controlled to have a predetermined resistance value Rs2 at the above ambient temperature. The resistance value Rs1 is smaller than the resistance value Rs2. The resistor 16 constituting the temperature-sensitive resistance element 10 and the first series circuit 19 is, for example, a fixed resistor having a resistance value R1 similar to the resistance value Rs1 of the temperature-sensitive resistance element 10. Further, the resistor 17 constituting the temperature compensating resistor element 14 and the second series circuit 20 is, for example, a fixed resistor having a resistance value R2 similar to the resistance value Rs2 of the temperature compensating resistor element 14.

Each of the sensor elements 3, 4, and 5 is set to a temperature higher than the ambient temperature, and when the wind is received, the temperature of the temperature-sensitive resistance element 10, which is a heat generation resistance, drops. Therefore, the potential of the output unit 21 of the first series circuit 19 to which the temperature-sensitive resistance element 10 is connected fluctuates. As a result, the differential output is obtained by the differential amplifier 23. Then, in the feedback circuit 24, a drive voltage is applied to the temperature-sensitive resistance element 10 based on the differential output. Then, based on the change in the voltage required for heating the temperature-sensitive resistance element 10, the wind speed can be converted and output by a microcomputer (not shown). The microcomputer is installed on the surface of the substrate 2, for example, and is electrically connected to each of the sensor elements 3, 4, and 5 via a wiring pattern (not shown) on the surface of each lead wire 7 and the substrate 2. There is.

Further, the temperature compensating resistance element 14 detects the temperature of the fluid itself and compensates for the influence of the temperature change of the fluid. As described above, by providing the temperature compensating resistance element 14, it is possible to reduce the influence of the temperature change of the fluid on the flow rate detection, and the flow rate detection can be performed with high accuracy. As described above, the temperature compensating resistance element 14 has a sufficiently higher resistance than the temperature-sensitive resistance element 10, and the temperature is set to be near the ambient temperature. Therefore, even if the temperature compensating resistance element 14 receives wind, the potential of the output unit 22 of the second series circuit 20 to which the temperature compensating resistance element 14 is connected hardly changes. Therefore, it is possible to accurately obtain a differential output based on the resistance change of the temperature-sensitive resistance element 10 with the potential of the output unit 22 as a reference potential.

The circuit configuration shown in FIG. 4 is an example and is not limited thereto.

In the present embodiment, the location of the temperature compensating resistance element 14 is not limited. For example, it can be arranged on the back surface of the substrate 2.

In the present embodiment, as shown in FIGS. 1 and 2, the first sensor element 3 is arranged parallel to the X direction in the plan view of the substrate 2. Here, the arrangement direction of the sensor element is a direction along the longitudinal direction of the sensor element (temperature sensitive resistance element 10). As shown in FIGS. 1 and 2, the second sensor element 4 is arranged on the left side of the drawing of the first sensor element 3, and is the first sensor element from the Y direction orthogonal to the X direction in a plan view. Arranged at an angle toward 3. In the present embodiment, the angle θ1 between the element surface 3a of the first sensor element 3 facing each other and the element surface 4a of the second sensor element 4 is arranged so as to be about 60 degrees. Further, the third sensor element 5 is arranged on the right side of the drawing of the first sensor element 3 and is arranged so as to be inclined from the Y direction toward the first sensor element 3 in a plan view. In the present embodiment, the angle θ2 between the element surface 3a of the first sensor element 3 facing each other and the element surface 5a of the third sensor element 5 is arranged so as to be about 60 degrees. As a result, the angle θ3 between the element surface 4a of the second sensor element 4 facing each other and the element surface 5a of the third sensor element 5 also becomes about 60 degrees. As shown in the plan view of FIG. 2, the first sensor element 3, the second sensor element 4, and the third sensor element 5 are arranged in a substantially equilateral triangle.

Further, as shown in FIG. 1, the first sensor element 3 is formed at the lowest position, the second sensor element 4 is formed at the next highest position, and the third sensor element 5 is the most. It is formed in a high position. That is, the first sensor element 3, the second sensor element 4, and the third sensor element 5 are arranged in this order away from the substrate 2. The height of each of the sensor elements 3, 4, and 5 is defined by the position of the temperature-sensitive resistance element 10 constituting the sensor elements 3, 4, and 5.

In the present embodiment, the wind direction and the wind speed can be detected at the same time by comparing the wind speed information obtained from these three sensor elements 3, 4, and 5. For example, for wind blowing along the X direction, the output from the circuit of FIG. 4 having the first sensor element 3 is the smallest (the output is almost zero), while the second sensor element 4 and the second. A predetermined output can be obtained from the circuit having the three sensor elements 5. Then, the wind direction can be detected by comparing the output values of the sensor elements 3, 4, and 5. Further, since the tilt angles of the sensor elements 3, 4, and 5 are known, the wind speed can be detected based on the output values of the sensor elements 3, 4, and 5.

Here, the principle of wind direction detection in the present embodiment will be described. FIG. 5 is a graph showing that when a wind is blown onto a flow rate sensor device in which only one temperature-sensitive resistance element is arranged, the wind speed value changes depending on the wind direction. That is, the wind speed value indicated by the sensor shown in FIG. 5 is the wind speed obtained from the configuration in which only one sensor element 3, 4, 5 provided in the flow rate sensor device 1 of the present embodiment shown in FIG. 1 is arranged. The value. It is assumed that the wind speed is constant from any direction.

FIG. 5 also shows the detection result of the wind speed value calculated from the differential pressure. As shown in FIG. 5, in the differential pressure, the output does not change depending on the wind direction, so that the wind direction cannot be detected. On the other hand, the output of the wind speed value indicated by the sensor changes depending on the relationship between the temperature-sensitive resistance element and the wind direction. As shown in FIG. 5, when the wind hits the surface of the temperature-sensitive resistance element vertically, the peak value of 11 m / s is detected, and the wind speed is detected when the wind direction gradually tilts with respect to the surface of the temperature-sensitive resistance element. The value is getting smaller.

In the configuration in which the three sensor elements 3, 4, and 5 are arranged so as to form an equilateral triangle as in the present embodiment, the outputs of the sensor elements 3, 4, and 5 are deviated as shown in FIG. Change. As shown in FIG. 6, the outputs of the sensor elements 3, 4, and 5 are out of phase by 60 degrees, respectively.

FIG. 7 shows the relationship between the sensor elements 3, 4, and 5 and the wind direction. In FIG. 7A, the longitudinal direction of the sensor element 3 and the wind direction coincide with each other. FIG. 7A corresponds to the angle of 0 degrees in FIG. 6, the output of the sensor element 3 is 0, and the output of the sensor elements 4 and 5 is about 0.8. When the sensor elements are rotated clockwise by 30 degrees as shown in FIGS. 7 (b) to 7 (g), the outputs of the sensor elements 3, 4, and 5 gradually change as shown in FIG. However, the angle formed by the direction of the wind hitting the sensor elements 3, 4, and 5 is in the range of 0 to 180 degrees, and the combination of the output values of the sensor elements 3, 4, and 5 at each angle is all different. Therefore, it is possible to detect the wind direction and the wind speed based on the output values of the three sensor elements 3, 4, and 5.

In the present embodiment, as shown in FIG. 1, it is preferable to change the height of each of the sensor elements 3, 4, and 5. As a result, the sensor elements 3, 4, and 5 do not act as barriers to interfere with each other's contact with the wind, and the wind direction and speed can be detected with high accuracy.

As shown in FIG. 1, the flow rate sensor device 1 of the present embodiment has a configuration including a substrate 2 and a plurality of sensor elements 3, 4, and 5 erected on the surface of the substrate 2, and is simple. With the structure, it is possible to detect the wind direction and the wind speed at the same time.

In the embodiment shown in FIGS. 1 and 2, the number of the sensor elements 3, 4, and 5 is set to 3, but the number is not limited. However, it is preferable that the sensor elements are arranged so that the surface of the adjacent sensor elements is tilted at an equal angle in a plan view. This facilitates comparative control of the wind speed information obtained from each sensor element, so that the burden on the control circuit for calculating the wind direction and the wind speed can be reduced, and the wind direction and the wind speed can be detected with high accuracy.

In this embodiment, three sensor elements 3, 4, and 5 are arranged so as to form an equilateral triangle in a plan view, so that the wind direction and speed can be determined with a small number of elements and with high accuracy. It can be detected and is suitable.

In the above, the flow rate sensor device 1 has been described as detecting the wind, but the fluid to be detected may be a gas or a liquid in addition to the wind.

In the present invention, the flow rate sensor device capable of simultaneously detecting the wind direction and the wind speed can be used, and can be applied to various applications. For example, by mounting a light emitting element such as an LED and controlling the color change according to the wind direction and the magnitude of the wind speed, illumination can be realized, and it can be applied to a wind control system or analysis. Is also possible.

1: Flow sensor device 2: Substrate 3: First sensor element 4: Second sensor element 5: Third sensor element 7, 8: Lead wire 10: Temperature sensitive resistance element 14: Temperature compensation resistance element 16, 17: Resistance Instrument 18: Bridge circuit 21, 22: Output unit 23: Differential amplifier 24: Feedback circuit

Claims (4)

With the board
It has a sensor element having a plurality of temperature-sensitive resistance elements arranged on the substrate, and has.
A flow rate sensor device characterized in that each sensor element is arranged at an angle to each other in a plan view of the substrate. The flow rate sensor device according to claim 1, wherein the sensor element is arranged so that the adjacent sensor elements are arranged so as to be tilted at an equal angle in the plan view. The flow rate sensor device according to claim 2, wherein three sensor elements are provided and arranged so as to form an equilateral triangle in the plan view. The flow rate sensor device according to any one of claims 1 to 3, wherein each sensor element is arranged at different heights with respect to the vertical direction of the surface of the substrate.

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