JPS6281571A - Apparatus for detecting fluid - Google Patents

Abstract

PURPOSE:To make it possible to detect the flow speed of a fluid with high accuracy by a simple structure, by providing a heat generating element in the upstream side of the fluid and a measuring element in the downstream side thereof and measuring the time required before the fluid heated by the heat generating element reaches the measuring element. CONSTITUTION:A heat generating element QH and measuring elements (QE or the like) are provided to a detection element part 2 so that the former is arranged in the upstream side of a fluid and the latter elements are arranged in the downstream side thereof. The heat generating element QH is intermittently driven to heat the fluid and the time required before the heated fluid part is detected by each of the measuring elements (QE or the like) is measured, and a flow speed is calculated from the measured value. When the flow direction of the fluid is unclear, the measuring elements QE-QN are provided at radial positions around the heat generating element QH and the flow direction can be measured by discriminating which measuring elements QE-QN detect the heated fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fluid detection device, and is intended to detect the velocity or direction of a fluid such as gas or liquid.

[Summary of the invention]

The present invention is a thermal fluid detection device configured to radiate heat generated in a heating element provided in a fluid to the fluid, in which heat generated intermittently and in a pulsed manner in the heating element is measured by the fluid. By moving the measuring element to the position of the element and detecting the flow velocity and direction of the fluid based on the pickup detection output obtained by the measuring element, highly accurate fluid detection can be performed with a simple configuration.

[Conventional technology]

Conventionally, this type of fluid detection device is used, for example, in an anemometer or anemoscope, in which a heat sensing element made of a transistor generates heat, and a part of the heat is removed by the wind while maintaining a predetermined relationship with the wind speed. Take advantage of the fact that you are going
For example, a method for detecting wind speed is disclosed in Japanese Patent Publication No. 59-48340.
This method is disclosed in Japanese Utility Model Publication No. 59-39643.

Further, a wind direction detection device for measuring wind direction using a heat sensitive element having such a structure is disclosed in Japanese Patent Application No. 84196/1983.

[Problem that the invention seeks to solve]

This type of so-called thermal anemometer is based on the principle of converting the amount of heat absorbed into the air into wind speed, so the measurement results may fluctuate depending on changes in the temperature at the location where the anemometer is installed. Therefore, a temperature measuring element is installed to measure the temperature so as not to be affected by the amount of heat generated by the heat sensing element, and a configuration is also required to correct the measurement result according to changes in the temperature. It is necessary to provide

The present invention has been made in consideration of the above points, and is based on the pickup output of the measuring element by moving heat intermittently generated from a heating element to a measuring element provided at a predetermined distance using a fluid. Therefore, the present invention attempts to propose a fluid detection device that can detect the flow velocity and direction of fluid without being affected by ambient temperature.

[Means for solving problems]

In order to solve this problem, in the first invention, a heating element Q is arranged at an upstream position with respect to the fluid flow, and a measuring element Q is arranged at a downstream position of this heating element QH.
8 to Q8 and the heating element Q are made to generate heat intermittently and in a pulsed manner, and the heat is transferred by the fluid to the positions of the measuring elements QN to Qi. , + pickup output D T N-D
Based on Tw, heating element Q and measuring element 08 to 01
．． A detection circuit unit 1 is provided which calculates the flow velocity of the fluid by detecting the heat transfer time between 1 and 1.

Further, in the second invention, a heating element Q is arranged at an upstream position with respect to the flow of fluid, and a plurality of measuring elements Q are arranged at a downstream position of this heating element Q. a detection element section 2 including a heating element Q;

generate heat intermittently and in pulses so that the heat is transferred to the positions of the measuring elements Q, -Q, 1 by the fluid,
Pickup output DT, -D of measuring element Q N-Q w
T1. A detection circuit section 1 is provided which determines the direction of fluid flow based on l.

[Effect]

When the heating element Q is generated intermittently and in pulses by the detection circuit section l, the heat is transferred to the positions of the measurement elements QM to Q on the downstream side by the fluid flowing through the fluid passage of the detection element section 2. Go.

When the heat reaches the measuring elements QN to Q on the downstream side,
Pickup output D Tu~ corresponding to the temperature change
DTw is generated and supplied to the detection circuit section 2.

At this time, the detection circuit section 1 detects the time from when the heating element Q generates heat until the pickup output is obtained at the measuring elements Q and -QW. The flow rate of the fluid is calculated from the distance between the heating element Q and the measuring elements 08 to 01.1.

Further, the detection circuit section 1 determines the direction in which the fluid flows based on pickup outputs obtained from the plurality of measurement elements.

Thus, in detecting the flow velocity and direction of the fluid,
By calculating the flow velocity from the travel time based on the heat generated intermittently and in pulses from the heating elements Q and 4, the flow velocity of the fluid can be calculated without being affected by the ambient temperature of the detection element section 2. and the direction of flow can be detected.

〔Example〕

An embodiment in which the present invention is applied to a fluid detection device for detecting wind direction and wind speed will be described in detail below with reference to the drawings.

FIG. 1 shows the fluid detection device as a whole, and the detection circuit section 1
and a detection element section 2.

The detection element section 2 is placed in a fluid to be detected (in this example, wind), and obtains a pickup output corresponding to the flow velocity (i.e., wind speed) and the direction in which the fluid flows (i.e., wind direction). , the configurations shown in FIGS. 2 and 3 can be used.

The detection element section 2 has a detector main body 10 having a shape substantially similar to that obtained by cutting off the upper end of a sphere in the horizontal direction. It is attached to the tip.

On the upper plane 11 of the detector body 10, four cylindrical ridges 13 are formed at the outer edge on virtual lines LLI and L12 extending through the center and perpendicular to each other, and the space between each ridge 13 and The upper plane 11 forms a cross-shaped fluid passage 14 passing through the upper plane 10 in mutually orthogonal directions.

Thus, when wind blows into the detection element section 2 from any direction in the horizontal direction, the wind is diverted by the ridges 13 as necessary to correspond to the direction, and the wind is routed through the corresponding branch of the fluid passage 14. is made to flow.

Note that the upper end of the protuberance 13 and the outer end of the fluid ill passage 14 are
It is chamfered in a streamlined shape (for example, bellmouth shape) so as not to disturb the flow of fluid.

In this way, the fluid passage 14 is connected to the first crossroads 1 in the north direction (represented by N) when viewed from the center position of the crossroads.
4N, a second crossroads 14S heading south (represented by S), and a second crossroad 14S heading east (represented by E).
E and the fourth fork in the west (represented by W) direction 1
4W. When the wind blows from the direction N, the wind blows through the fluid passage 14 in the direction S through the branch paths 14N and 14S. Conversely, if the wind blows from the direction S, it will blow in the direction N through the crossroads 14S and 14N. Similarly, if the wind blows from the direction E or W, it will blow through to the west through the crossroads 14E and 14W, or through the crossroads 14W and 14E to the east.

Furthermore, when the wind blows from an intermediate direction among these four directions, the ridge 13 divides the wind into forks on both sides, so that the wind is split through two adjacent forks. There is. In other words, when the wind blows from the direction of the northeast (NE), it blows through the path of crossroads 14N and 14W and the path of crossroads 14E and 14s. ,
It blows through through crossroads 14E and 14N and 14S and 14W. Also, the wind in the southwest (SW) direction is at crossroads 14.
It blows through through s and 14E, and 14W and 14N. Further, the wind in the northwest (NW) direction blows through the crossroads 14W and 14S, and 14N and 14E.

A heating element QN made of a transistor is provided at the center of the fluid passage 14 having such a cross-path configuration, so that when wind passes through the center of the fluid passage 14, this heating element Q
It is designed to take away the HO heat and transport it to the downstream crossroads.

In addition to this configuration, on the upper plane 11 of the fluid passage 14, each branch path 14N, 14E,
When looking at 14S and 14W, measuring elements Q3, Qw, Q, and Qt are arranged at positions on the virtual circle of radius R of each branch, and thus the heat generated in the heating element Qll is transferred by the wind. The amount of heat extracted from each measuring element Q8, Q, 4, QN, Q when it is carried to the measuring elements Q3, Qo, QH, Qf located at a distance of radius R. It is possible to obtain the corresponding pickup output.

As shown in FIG. 1, the heating element Q is driven and controlled by constant current sources 21HH and 2IHB provided in the detection circuit section 1 so as to generate heat intermittently. In other words, the constant current source 21HB constantly outputs this constant current output (■) to the heating element Q.
, poured into the base of l. On the other hand, the constant current rX21■IH converts the constant current output Ill (FIG. 4(B)) into the output pulse C
L and K (FIG. 4(A)), the current flows into the collector of the heating element Q11 only during the rising pulse width. In this way, the heating element QII generates heat corresponding to the collector loss determined by the base current I, only during the rising width of the output pulse CP, at the repetition period thereof, as shown in FIG. 4(D). , temperature TEM of heating element Q,
, will intermittently rise from room temperature TA.

On the other hand, the measuring elements QN, Qt, Qs, and Qw have a so-called diode-connected configuration in which the base and collector are connected, respectively, and constant current sources 23N, 23E, 23S, and 23W are provided at the base of the detection circuit section l. A constant current output ■7 is injected from the emitter and flows to ground through the emitter.

When diode-connected in this way, the measuring element Q, -
The base voltage of Q, depending on the junction temperature (therefore, the ambient temperature), becomes almost a straight line if the temperature TEMs to TEMw (Fig. 4 (El) to (E4)) rises from room temperature TA. It is controlled so that it exhibits characteristics that reduce the In this way, when the ambient temperature of the measuring elements QN to Qw increases, the base voltage decreases accordingly, and the temperature pickup outputs DTN, D T E , D T s change in response to the change in the base voltage. , D Tw
, the detection signal input circuits 24N, 24E, 243, respectively.
．． Sends out to 24W.

The detection signal input circuits 24N to 24W set a predetermined threshold level (the corresponding temperature is indicated by the symbol T in FIG. 4 (E2)) for the temperature pickup outputs DT, -DT.
A detection signal that receives a comparison input THL having a comparison input THL (indicated by I) and compares it with the temperature pickup output DT, ~DT, and falls to a logic "L" level when the temperature pickup output DT, ~DT becomes lower than the comparison human power THL. T, 4~T
((Fl) to (F4) in FIG. 4) are supplied to the moving time signal forming circuits 25N to 25W. - The travel time signal forming circuits 25N to 25W are connected to heating elements QH.
When it generates heat in a pulsed manner, and the heat moves while being carried by the wind to one of the measuring elements Q, -QW, a travel time signal T r M N~ representing the travel time is generated.
TIMw (FIG. 4 (Gl) to (G4)) is generated.

The travel time signal forming circuits 25N to 25W are JK flip-flop circuits having truth values as shown in FIG.
100 outputs are sent out as travel time signals TIM, ~TIMw. A reset pulse R3 (FIG. 4(C)), which is generated at the timing when the clock pulse CLK rises in the reset pulse generation circuit 26, is applied to the reset input terminals R of the travel time signal forming circuits 25N to 25W. While R3 maintains the logic rHJ level, the moving time signal forming circuits 25N to 25W are reset to force the moving time signals TIM, -TIM, obtained at the -d output terminal, to the logic rHJ level. (Fig. 4 (G1) to (04)).

When the reset pulse Rs falls to the logic "L" level from this state, the moving time signal forming circuits 25N to 25W receive the detection signals T, -T, 1 at the clock input terminal CP, and the logic level thereof becomes " The reset state is maintained until the voltage falls from "L" to "I".

In this state, a pick-up output is eventually obtained from the measuring element QH-Q, 1, and the logic level of the detection output T, ~Th once falls to rLJ and then returns to rHJ.
By this rising edge, the moving time signal forming circuits 25N to 25
W is set and its output falls to the logic rLJ level. Thus, the travel time signal forming circuit 25N to 25W
During the travel time of TIMN-TIM, the heat carried by the wind is transferred to the measuring element Q from the point in time when the heating of the heating element Q is completed (i.e., the point in time when the current I11 stops flowing).
The logic rHJ level is reached until the time when the heat generating element Q has passed the position N-Q (therefore, the time it takes for the heat generated in the heating element Q to reach the positions of the measuring elements Q8 to Q1).

After that, the reset pulse R of the reset pulse generation circuit 6
3 rises to the logic "Hj level" (4ffia), the moving time signal forming circuits 25N to 25W are reset and return to their original state.

On the other hand, if the detection signal T N -T w does not arrive after being reset by the reset pulse R3, the moving time signal forming circuits 25N to 25W are not set, and therefore the moving time signals TIM, to TIMP maintains a logic rHJ level.

The moving time signals T I MN to TIM are given as gate signals to the Nant gate circuits 32N to 32W, and the count pulse generating circuit 31 is counting while the moving time signals TIM, l to TIM rise to the logic "H" level. The pulse C0NP is given to the reciprocal counters 33N to 33W as a count input.

The reciprocal counters 33N to 33W receive the count pulse C0N.
P is counted, and the reciprocal of the count result is output to the arithmetic circuit 34 as wind speed data vH-v.

Here, the number of pulses of the count pulse C0NP that passes through the gate circuits 32N to 32W and reaches the reciprocal counters 33N to 33W is determined by the distance R of the heat generated in the heating element Q.
It represents the travel time LH"'Lw until the measuring elements Q and -Qw, which are located at positions separated by Therefore, the heat generated in the heating element Q□ is transferred to the heating element QH.
The moving speed (therefore the wind speed) v, , "-v- data from Q, to reach Q,-Q, can be obtained based on the following equation.

The wind speed data VN''-V represents the 90'' component of the wind vector when the wind blows through the fluid passage 14 of the detection element section 2. For example, when the wind is blowing from the direction E, the speed data l/
E is obtained, and from this it can be determined that the direction of the detected wind is E and the wind speed is .

On the other hand, when the wind is blowing from the northeast, wind speed data VN representing the vector component in the direction N is obtained from the reciprocal counter 33N, and wind speed data V representing the vector component in the direction E is obtained from the reciprocal counter 33E. can get.

As a result, the direction of the wind to be detected is northeast, and the wind speed can be determined as the absolute value of a composite vector whose vector components are the wind speed data v% and V.

The calculation circuit 34 determines the wind direction from the wind speed data Vll to v, and calculates the wind speed V from the following equation, and sends the determination result and the calculation result to the wind speed and direction display 35 for visual display.

In this embodiment, a reset pulse R5 is applied to the reciprocal counters 33N to 33W, whereby the contents of the repeated count are reset at the cycle of the clock pulse. In this way, wind speed and direction calculations are performed for each cycle of the clock pulse.

In the above configuration, each time the clock pulse CLK (FIG. 4(A)) of the clock pulse ordering circuit 22 is generated intermittently at a predetermined period, the heating element Q□
The amount of heat corresponding to the collector loss determined by the base current flowing from 1HB is generated, and as a result, the temperature T゛EM of the heating element Q (Fig. 4 (D)) changes intermittently in a pulsed manner at a predetermined period. Rise.

A part of the heat generated in the heating element Q is absorbed by the fluid (wind in this embodiment) passing through the fluid passage 14 of the detection element section 2 (FIGS. 2 and 3), and the heat is absorbed by the fluid (wind in this embodiment). It moves with the wind to the crossroads on the downstream side.

The speed and direction of this heat transfer corresponds to the speed and direction of the wind blowing into the fluid passageway 14. Therefore, after a period of time corresponding to the wind speed has elapsed, each time the heat carried by the wind arrives at the downstream detection element Q, ~Q, located at a distance R from the heating element Q8, Temperature of measuring element Q s ”' Q h T E M N - T E
M w ((El) to (E4) in FIG. 4) increases intermittently and in a pulsed manner.

Here, if the wind direction is E, the temperature TEMi of the measuring element QE on the leeward side of the heating element Q (Fig. 4 (E2))
increases from room temperature TA, whereas other measuring elements T E MN , T E Ms , T E Ff11
No change occurs in + and +.

As a result, the detection signal TN falls to the logic rLJ level in response to the heat transferred from the detection signal input circuits 24N to 24W corresponding to the measurement elements Q and -Qw located downwind.
TW (FIG. 4 (Fl) to (F4)) is obtained, and the movement time signal forming circuits 25N to 25W are driven by the detection signal T N''T w.

The travel time signal TIM thus falls to the logic rLJ level for a time corresponding to the wind travel time.

~TrMw (Fig. 4 (Gl) ~ (G4)) is generated.

As a result, the reciprocal counter 33E performs a counting operation through the gate circuit 32E corresponding to the measuring element Qt located downwind, so that the wind speed data V representing the wind speed is transmitted to the calculation circuit 33.
Sent on 4th. At this time, the other reciprocal counter 33N
, 33S, 33W wind speed data VNS vs , ■□
is not sent out, so it can be seen that the wind direction is E.

The wind speed and direction calculation circuit 34 uses these wind speed data VN~v
1. perform a vector operation on the wind speed based on l;
The calculation results are displayed on the wind speed and direction indicator 35.

The above case shows the behavior when the wind blows in the wind direction E, but if the wind blows in an intermediate direction, for example from the northeast,
Heat transfer occurs to QE and G2, and the transfer time has a value corresponding to the speed of the wind component blowing from the heating elements Q and I toward the measurement elements QE and QN. Therefore, wind speed data corresponding to the relevant wind speed is stored in the reciprocal counters 33N and 33H as wind speed data vN and V. The calculation circuit 34 executes vector calculation using these two wind speed data v8 and vE as mutually orthogonal vector components, calculates the direction and wind speed of the currently blowing wind, and displays the wind speed and direction indicator. 35.

In this manner, according to the above-described embodiment, the wind speed and direction of the wind to be detected are determined by the heat generated intermittently and in pulses in the heating elements Q and l by the downstream measuring element Q N ""
The wind speed and direction can be reliably detected based on the travel time until moving to Qw. In doing so,
Since the travel time for heat to be transferred by the wind does not depend on the air temperature at the position where the detection element section 2 is provided, the wind speed and direction obtained as measurement results can be made unaffected by the air temperature.

Therefore, unlike the conventional case, there is no need for a structure for correcting the measurement result depending on the ambient temperature, and it is possible to obtain a fluid detection device with a simpler overall structure compared to the conventional case.

In the above-described embodiment, a case was described in which wind was measured as a fluid, but the flow velocity and flow direction of the fluid can be reliably detected in the same manner as in the above-mentioned case for other gases and fluids.

Furthermore, in the above-described embodiment, a case has been described in which the direction of fluid flow is detected in all directions with the heating element Q as the center, but in the case where the fluid passage 14 is limited to a straight line, In this case, the fluid flows in two directions, forward and reverse, but in such a case, the heating element Q,
Two measuring elements may be provided at positions facing each other with this in between. Even in this manner, it is possible to obtain a fluid detection device that can reliably detect the fluid flow velocity and its direction (forward or reverse direction).

Also, in this case, if the direction of fluid flow is one of the forward and reverse directions, there is no need to detect the direction of fluid flow, but the flow velocity in this case can be measured in the same way as in the above case. It can be done.

Further, in the above-described embodiments, the configurations shown in FIGS. 2 and 3 were used as the detection element section 2, but the configuration is not limited thereto, and various configurations may be used.

〔Effect of the invention〕

As described above, according to the present invention, a fluid detection device capable of detecting fluid with high accuracy can be realized in a container with a simpler configuration than in the conventional case.

[Brief explanation of drawings]

FIG. 1 is a connection diagram showing one embodiment of the fluid detection device according to the present invention, FIGS. 2 and 3 are perspective views and plan views showing the mechanical configuration of the fluid detection section, and FIG. 4 is the same as the one shown in FIG. 1. FIG. 5 is a chart showing truth values of the moving time signal forming circuit of FIG. 1. l...detection circuit section, 2...detection element section, lO...detector body, 14...fluid passage, 22... Clock pulse generation circuit, 24
N~24W...Detection signal input circuit, 25N~2
5W...Movement time signal forming circuit, 31...
・・Count pulse generation circuit, 32N~32W・・・・
... Gate circuit, 33N to 33W ... Reciprocal counter, 34 ... Wind speed and direction calculation circuit, 35 ...
...Wind speed and direction indicator, Q, ...Heating element, Q
N~Q,... Measuring element.

Claims (2)

[Claims] (1) A detection element section having a heating element disposed upstream of the fluid flow and a measuring element disposed downstream of the heating element; by generating heat and transferring the heat to the position of the measuring element by a fluid, and detecting the transfer time of the heat between the heating element and the measuring element based on the pickup output of the measuring element. , and a detection circuit section that calculates the flow velocity of the fluid. (2) a detection element section having a heating element disposed upstream of the fluid flow and a plurality of measurement elements disposed downstream of the heating element; and a detection circuit section that generates heat in a pulsed manner and moves the heat to the position of the measurement element by the fluid, and determines the direction in which the fluid flows based on the pickup output of the measurement element. Characteristic fluid detection device.