JPS5937419A - Heat sensitive type flow rate detector - Google Patents

Abstract

PURPOSE:To realize true mass measurement with a device having a smaller size, lighter weight and higher performance by the simple constitution of forming a heating element and strain detecting elements on the same diaphragm. CONSTITUTION:A heating element 9 consisting of a low resistance impurity layer of (p) type silicon and strain detecting elements 10 consisting of a high resistance impurity layer of (p) type silicon are so constituted as to be embedded or adhered in a pressure receiving diaphragm 11. Mineral spirit 6 is accelerated by a nozzle 22 to jet and collides against the diaphragm 11. The mass flow rate of corrected density is determined by the transmission of the cooling heat using the element 9 and a dynamic pressure is determined by the pressure conversion using the elements 10. Therefore the flow rate approximate to the true mass flow rate is measured if adequate arithmetic processing is performed in a detection circuit part.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow rate detector that detects the flow rate of a fluid object using heat transfer between a heating element and a fluid object. The present invention relates to a heat-sensitive flow rate detector that detects the amount of flowing fluid, such as flow rate or flow rate, based on the amount of heat transfer.

An example of a conventional flow rate detector of this kind is shown in Fig. 1. In the figure, (1) is a bulk heating element made of silicon semiconductor; (2) is a bulk heating element (1) made of a silicon semiconductor; An electrode board that has both the function of supplying power and the function of supporting it, 0)
is a support corresponding to a transistor package that holds this electrode lead (2), (4) is an extraction lead, and (S
)/i stainless steel plumbing pipe, (6) is the mineral spirits that is the fluid passing through the interior of this plumbing pipe (5), and (7) is the differential bridge connected to the extraction lead (4). A detection circuit (8) including an amplifier is a detection output signal obtained from this detection circuit (7).

The operation of the device configured in this way will be explained. First, let the power supplied to the bulk heating element (1) be Pin,
If the amount of heat transfer between the bulk heating element (1) and the mineral spirits (6) is Pout, then in a state of thermal equilibrium, Pin −Pout = h−As ·ΔT holds true. Therefore, h is the transmission coefficient between the bulk heating element (1) and the mineral spirits (6), and Am is the transmission coefficient between the bulk heating element (1) and the mineral spirits (6).
The surface area of 1), ΔT, is the temperature difference between the bulk heating element (1) and the mineral spirits (6).

Generally, under laminar flow conditions where the Reynolds number Re is I(Re(2000), the heat transfer measure is as follows, where a and b are constants.
The formula h=a b°v −C can be calculated as follows. Here, V means the average flow velocity of the fluid.

And power supply Pin// to the bulk heating element (1)
i If the resistance of the bulk heating element (1) is Ra, the current is Is, and the voltage is v8, then Pin = Ig - Ra = V
Since it is expressed as II/Re, when the electrical impedance of the bulk heating element (1) is measured by the detection circuit σ), the flow velocity V or flow rate Q of the fluid is the detection output signal (8).
obtained as.

Here, the bulk heating element 0) is 0.7X0.7X0.1
It consists of a 5m N-type homogeneous material. The support 0) is a To-46) transistor package, and the stainless steel piping (5) is 0.
．． 76751 diameter x 30cm long leg, bulk heating element (1
) is installed at the rear 25.3cIr1.

However, in this heat-sensitive flow rate detector, the Reynolds number is 2000 to 3000, avoiding the transition region from laminar flow to turbulent flow where the flow becomes unstable.
Since we are forced to set the conditions to 0.00 or less, we have no choice but to use a low value for the heat transfer coefficient and a laminar flow state for the flow. Furthermore, since the silicon chip serving as the heating element (1) is a homogeneous bulk heating element, there is a drawback that the heat capacity is large and the thermal time constant for reaching a thermal equilibrium state is also relatively large. In addition, the bulk heating element (1) has a certain size, and the electrode lead (2
) and become an external element that disturbs the flow, resulting in low responsiveness as a flow detector or unstable characteristics at minute flow rates or large flow rates.

In view of the above points, the present invention has been made in order to solve such problems and eliminate such drawbacks.The purpose of the present invention is to form a jet flow and make it collide with a diaphragm, thereby creating a gap between a heating element and a flowing fluid. By measuring heat transfer and the amount of deformation of the diamond/7 ram, it is possible to create a small, lightweight, and high-performance flow rate detector that can measure flow rates close to the true mass flow rate at a low cost. An object of the present invention is to provide a fully heated flow rate detector.

In order to achieve such an object, the present invention provides a flow velocity increasing means using a throttling mechanism such as a throttle or a nozzle that narrows the flow path of a flowing fluid to increase the flow velocity, and a flow velocity increasing means placed behind the flow velocity increasing means. A diaphragm that deforms under pressure according to the flow velocity of the flowing fluid; a heating element embedded in or bonded to the diaphragm; a strain detection element embedded in or bonded to the diaphragm; Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a configuration diagram showing an embodiment of a fully heated flow rate detector according to the present invention. In Fig. 2, the same reference numerals as in Fig. 1 indicate corresponding parts; (9) is a heating element made of a low resistance impurity layer of P-type silicon, and (10) is a heating element made of a low resistance impurity layer of P-type silicon as well as ti. The strain sensing element is a layer-by-layer strain sensing element, and these heating element (9) and strain sensing element (10) are configured to be embedded or bonded to a pressure receiving diaphragm, which will be described later. (11) is a pressure-receiving diaphragm made of an N-type silicon substrate whose central part has been etched to make it thinner, and the pressure-receiving diaphragm (11) is located behind a flow velocity increasing means using a restriction mechanism such as a restriction or a nozzle. It constitutes a diaphragm that deforms under pressure according to the flow velocity of the flowing fluid. Here, the pressure receiving diaphragm (11) is not particularly limited to silicon, but may be made of Ge or a compound semiconductor such as InSb or GaAs as long as it can form a resistance layer.

(12) is a hollow part, and this hollow part (12) is sealed under a constant pressure such as a vacuum state, and deforms due to the total pressure that is the sum of static pressure and dynamic pressure of mineral spirits (6). is configured to do so. (13) is 5iOz p
This oxide film insulating layer (13) is particularly 8i0
Not limited to z, if the material has electrical insulation properties, 5ixN
a, A/20a may be used. (14) is an aluminum electrode layer, and this electrode layer (14) is not limited to aluminum either (it may be made of known electrode materials such as Au, Ni, or Pt. (15) is a bonding wire ,(
16) is a bonding boss), (17) is an adhesive layer such as glass solder, and this adhesive layer (17) is made of Zn 0-, which has a coefficient of thermal expansion close to that of silicon, in order to achieve airtight sealing at a relatively low temperature. B2us-Vz05 type glass solder is used, but alloys such as Au-81 and synthetic resins such as epoxy type and silicon type may also be used. (
18) is a support made of, for example, borosilicate glass, and this support (18) is preferably made of a material with a coefficient of thermal expansion close to that of the pressure receiving diaphragm (11), and if it is similar, it is not limited to borosilicate glass. Ceramic material may also be used. These ceramic materials include coachillite and zircon.

Porcelain such as Lithia is suitable. And this support stand (
Reference numeral 18) supports the peripheral portion of the pressure receiving diaphragm (11) and constitutes a supporting means made of a hot white defective conductor.

(19) a package made of Hakovar, (20) a bonding boss made of electrically insulating material such as haceramic, an insulator that insulates and supports (16), (21) a housing, and (22) a nozzle. (22) U constitutes a flow velocity increasing means using a constriction mechanism that narrows the cross-sectional area of the flow path of the flowing fluid to increase the flow velocity.

Although mineral spirits (6) are used as the flowing fluid, the present invention is not limited to this, and can be applied to most fluids such as fuel oil, water, and air, and is particularly suitable for insulation. Suitable for sexual fluids. Furthermore, it is fully applicable to non-insulating fluids by coating the aluminum electrode # (14), bonding wire (15), and bonding post (1G) with an insulating film.

As is clear from the foregoing, the pressure receiving diaphragm (11) is made of a semi-conductive material, and the pressure receiving diaphragm (11) is made of a silicone material. As shown in Figure 2, it has a structure in which the central portion is thinner than the peripheral portion. The heating element (9) is connected to the pressure receiving diaphragm (1).
This heating element (9) is placed in the center of the pressure receiving diaphragm (11), and this heating element (9) is used as an impurity diffusion layer to form the pressure receiving diaphragm (1). 11) It has a structure that can be buried inside.

The strain sensing element (10) is made into an impurity diffusion layer and is embedded in the pressure receiving diaphragm (11).
This strain detection element (10) is disposed on the thinned part of the pressure receiving diaphragm (11), and this strain detection element (10)
are arranged around the thinned portion of the pressure receiving diaphragm (11).

Next, the operation of the embodiment shown in FIG. 2 will be explained. First, mineral spirits (6) are nozzles (22)
The speed of the jet is increased, and it becomes a jet and collides with the pressure receiving diaphragm (11). Then, part or all of this jet collides with the heating element (9), and cooling heat transfer is performed as expressed by the following equation (1).

0.4 0.5k Pin= Pout=0.94 Pr ReD Stone・A11・ΔT −1ll Here, D is the nozzle diameter, Pr
is the Prandtl number, ReD is the Reynolds number, and k is the thermal conductivity. In addition, Pin is fj>electric power (F), Pou
t is the amount of heat transfer.

Transforming this, 6.4 pUj O5 '' 0.94Pr () ' ・k-As-ΔT
・+3). Here, Uj is the ejection speed, ν is the kinematic viscosity coefficient, and μ is the viscosity coefficient.

In equation (2) above, the factors that depend on the temperature of the fluid are the Prandtl number Pr, the thermal conductivity, the kinematic viscosity coefficient, and the power input to the fluid (9) (power supply) Pin, which is proportional to the ejection speed Uj'. Thus, a nonlinear relationship is established.

Generally, in a liquid, as the temperature of the fluid increases, the Prandtl number Pr and the kinematic viscosity coefficient ν decrease, but the thermal conductivity remains unchanged. Furthermore, in the case of a gas, as the temperature of the fluid increases, the kinematic viscosity coefficient ν and the conductivity k increase, and the Prandtl number Pr remains unchanged by about 9. Therefore, according to equation (2) above,
Whether the fluid is liquid or gas, in general, the Prandtl number Pr and kinematic viscosity coefficient ν are the Prandtl number Pr and kinematic viscosity coefficient ν for liquids, and the kinematic viscosity coefficient ν and thermal conductivity k are the effects of canceling the temperature dependence of input power (supplied power) Pin. However, in a narrow operating temperature range, there is no need to perform temperature compensation other than constant temperature difference operation, such as adding a temperature detection element.

However, the above-mentioned offset effect is limited, and if the operating temperature range is wide, it is desirable to provide a separate temperature detection element and perform characteristic compensation for the temperature of the fluid.゛And, in addition to the cooling heat transfer, the collision of the jets exerts pressure on the pressure receiving diaphragm (11), and the pressure receiving diaphragm (11)
) to transform. As mentioned above, this deformation is based on the total pressure, which is the sum of the dynamic pressure, which corresponds to the kinetic energy of the fluid per unit volume, and the static pressure, which corresponds to the potential energy of the fluid per unit volume.

Therefore, similar to the principle of Pitot-Veturi tube combination, if the static pressure value of the fluid at any other location is known, the dynamic pressure %4pUj can be determined.

On the other hand, the strain detection element (10) constitutes a full bridge with four elements, which are often employed in known semiconductor diffusion expansion pressure detectors, and has linear pressure conversion characteristics. Therefore, the characteristics of the dynamic pressure tumor pUj2 are directly measured as the output of a detection circuit such as a differential amplifier.

As described above, the density-corrected mass flow mpUj by cooling heat transfer using one heating element (9) is transmitted to the strain sensing element (10
J) pUj is determined by pressure conversion using )ft, so if appropriate arithmetic processing is performed in the detection circuit section, it is possible to measure something even closer to the true mass flow rate. Even in the case of a two-phase flow such as a liquid flow containing bubbles or a gas flow containing droplets, there are two functional relationships that determine the flow velocity, so the true mass flow rate can be measured.

In the embodiment shown in FIG. 2, the fluid flow is configured to be bent 90 degrees and discharged after impinging on the pressure receiving diaphragm (11). Therefore, the heat capacity of the heat generating portion is small, and high-speed response on the order of mmec is also possible. In addition, the flow near the pressure receiving diaphragm (11) is in a turbulent region with a Reynolds number of 3000 or more due to the nozzle (22), and is set to always be in a turbulent state within the measured flow rate range, so stable output can be obtained. Are you an idiot?
It has the advantage of being much smaller and lighter than conventional ones. Furthermore, the collision energy of the jet and the pressure receiving diaphragm (
11) Because of the vortices generated nearby, dust and other deposits are difficult to adhere to, the characteristics change little over time, and are excellent in durability. Furthermore, as shown in FIG. 2, this flow rate detector has a structure that allows easy installation and replacement.

Furthermore, since semiconductor materials are applied, it is excellent in mass production and can be produced at low cost and with high performance. Although the explanation has been given here by taking an N-type silicon substrate as an example, the same can be said for a P-type silicon substrate as well.

FIG. 3 is a configuration diagram showing another embodiment of the present invention, in which a heating element (9), a strain detecting element (10) and a total pressure receiving diaphragm (1
1) An example is shown in which the structure is laminated, that is, bonded.

In Fig. 3, the same reference numerals as in Fig. 2 indicate corresponding parts, and (23) is an insulating film made of electrically and thermally insulating material that covers the whole or part of the pressure receiving diaphragm (11). be. The material of this insulating film (23) is a metal oxide film, a heat-resistant polymer film, S10.5t02, M
These include vapor-deposited thin films such as fFx, CaPz, and ZnS.

The heating element (9) is made of a thermistor, which is a temperature-sensitive resistance material that can be laminated, a carbon film, an oxide thin film of Snow or TiO2, a noble metal thin film such as Pt, Au, or Pd, or a thin film of a noble metal such as Ti, Cr, Zr, Mo, Metal thin films such as Ta and W, or NL-Cr, Au-Cr,
It is made of alloy thin films such as Cr-Ti and manganese. Also,
The strain detection element (10) is a known resistance wire strain gauge.

A semiconductor strain gauge is used. In addition, these heating elements (
9) and the pressure receiving diaphragm (11) on which the strain sensing element (10) is laminated is made of a magnetic material such as metal such as stainless steel or a semiconductor such as silicon that can form a film body.

As is clear from the above, the pressure receiving diaphragm (11) is made of a metal material, and as shown in FIG. 3, the pressure receiving diaphragm (11) has a structure in which the center portion is thinner than the peripheral portion. . The heating element (9) has a structure that is adhered onto the surface of the pressure receiving diaphragm (11), and is arranged at the center of the pressure receiving diaphragm (11). Further, the strain detection element (10) is also bonded onto the surface of the pressure receiving diaphragm (11).

Next, the operation of the embodiment shown in FIG. 3 will be explained. Although the manufacturing method and material of the element in the embodiment shown in FIG. 3 are different from those in FIG. 2, the operation is basically the same as the embodiment shown in FIG. It operates almost the same as the embodiment shown.

Here, the difference from FIG. 2 is that in the embodiment shown in FIG. 3, the responsiveness of cooling heat transfer is improved compared to the embodiment shown in FIG.

This is because the pressure receiving diaphragm (11) and the heating element (9) are thermally insulated by the insulating film (23), so that leakage of heat flow to the pressure receiving diaphragm (11) is suppressed. .

Furthermore, by using a material with a high resistance temperature coefficient such as a thermistor for the heating element (9), the output can be increased and the burden on external detection circuits such as a differential amplifier can be reduced.

FIG. 4 is a block diagram showing still another embodiment of the present invention.

In FIG. 4, parts that are the same as those in FIG. 2 are given the same reference numerals and explanations will be omitted.

The difference from FIG. 2 is that the static pressure of the fluid is introduced into the pressure receiving diaphragm (11).The difference between the embodiment shown in FIG. 4 and the embodiment shown in FIG. This is because an inlet (24) is provided, and this inlet (24) is configured so that fluid is introduced through the support (18). Note that the other configurations are completely the same as the embodiment shown in FIG.

In the flow rate detector configured in this way, first, the pressure receiving diaphragm (6) collides with the mineral spirits (6).
As mentioned above, the total pressure of the fluid is applied to the surface of the pressure receiving diaphragm (11), but the static pressure of the fluid is applied to the back surface of the pressure receiving diaphragm (11), so the amount of deformation of the pressure receiving diaphragm (11) depends on the fluid It depends on the dynamic pressure 'Ap Uj.

Therefore, as in the embodiments shown in FIGS. 2 and 3, dynamic pressure can be directly measured without using other static pressure measuring means. The basic principle of this operation is similar to that of a pitot static pressure tube, and can be realized in an extremely narrow local space. In this way, except for directly measuring the amount of dynamic pressure, the other operations are similar to the embodiment shown in FIG. 2, so a description thereof will be omitted here.

As described above, in the embodiment shown in Fig. 4, mass measurement including up to two-phase flow is possible just by using a narrow space, and high performance is achieved using a small, lightweight, and inexpensive detector. A flow rate detector can be realized.

FIG. 5 is a block diagram showing still another embodiment of the present invention. In FIG. 5, the same parts as in FIG. 2 are given the same reference numerals, and their explanation will be omitted.

The difference between the embodiment shown in FIG. 5 and the embodiment shown in FIG. 2 is that an inlet (24
), the static pressure of the mineral spirits (6) is transferred to the pressure receiving diaphragm (24) through this inlet (24).
11). and,
The method for forming such an inlet (24) is based on a known etching process, and FIG. 6 shows an enlarged view of only the portion relating to the hole (11). FIG. 6 is a bottom view of the pressure-receiving diaphragm (11) viewed directly from below, and in this figure, four inlets (24) are drilled by etching.

The basic operation of the flow rate detector configured in this way is the same as that of the embodiment shown in FIG.
24) is close to the pressure receiving diaphragm (11), the net amount of dynamic pressure can be detected. In addition to the effect of discontinuity caused by the introduction port (24), stress is proportional to the square of the film thickness, and the introduction port is extremely small. By arranging it in such a way as to avoid it, it can be almost ignored.

As is clear from the above, Figures 4 and 5
In the embodiment shown in the figure, the pressure receiving diaphragm (11)
configured such that one side of the is subjected to the total pressure of the flowing fluid;
The other surface is configured to receive the static pressure of the flowing fluid, and the dynamic pressure of the flowing fluid causes the pressure receiving diaphragm (1
1) is configured to be deformed under pressure.

Note that this configuration can also be applied to the embodiments shown in FIGS. 2 and 3 by providing an inlet.

As is clear from the above description, according to the present invention, a compact structure capable of true mass measurement is achieved with a simple configuration in which a heating element and a strain sensing element are formed on the same diaphragm without using complicated means. Moreover, since a lightweight, high-quality flow rate detector can be realized at a low cost, the practical effect is extremely large.

In addition, due to the collision energy of the jet and the vortices generated near the pressure receiving diaphragm, it is difficult for dust and other deposits to adhere to the sensor, resulting in less change in characteristics and excellent durability, as well as easy installation and replacement of the detector. It is extremely effective in that it has the following advantages and enables mass flow measurement including up to two-phase flow.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an example of a conventional heat-sensitive flow can detector.
FIG. 2 is a block diagram showing one embodiment of a heat-sensitive flow rate detector according to the present invention, and FIG. 3 is a block diagram showing another embodiment of the present invention.
4 and 5 are configuration diagrams showing still another embodiment of the present invention, and FIG. 6 is an explanatory diagram showing an enlarged portion of the pressure receiving diaphragm in the embodiment of FIG. 5. (6)・・・Mineral spirits, (9)・・・
Heating element, (10)...Strain detection element, (11)...
...Pressure diaphragm, (1B) ...Support stand, (2
2)...Nozzle. Agent Makoto Kuzuno - Procedural amendment (voluntary) 1. Indication of the incident: Patent Application No. 57-148712 2,
Title of the invention Thermal wave quantity detector 3, To the representative Hitoshi Katayama of the person making the amendment (1) Claims column of the specification (2) Detailed description of the invention column 6 of the specification, Amendment Contents (The scope of claims in Specification 11 is amended as shown in the attached sheet. (2) "Hot white defective conductor" on page 8, line 9 of the same book is amended to read "1 thermally defective groove body". (3) Same book Correct “hot glow defective conductor” on page 10, line 13 to “thermal defective conductor”. (4) Correct “Pitot-Peturi tube” on page 14, line 14 of the same book to “Pitot-Venturi tube”. Attached sheet [(1) In a heat-sensitive wave quantity detector that detects the flow rate or flow rate of a flowing fluid from the amount of heat transfer between a heating element and a flowing fluid, the cross-sectional area of the flow path of the flowing fluid is A flow speed increasing means using a throttle mechanism that increases the flow speed by narrowing the flow speed, a diaphragm placed behind the flow speed increasing means and deforming under pressure according to the flow speed of the flowing fluid, and a heating element embedded or bonded to the diaphragm. A heat-sensitive wave quantity detector comprising: a strain detection element embedded in or bonded to the diaphragm; and supporting means that supports a peripheral portion of the diaphragm and is made of a thermally poor conductor. (2) A heat-sensitive wave quantity detector according to claim 1, characterized in that the diaphragm that deforms under pressure is made of a semiconductive material. (3) A patent characterized in that the diaphragm that deforms under pressure is made of a silicone material. A heat-sensitive wave quantity detector according to claim 2. (4) A diaphragm that deforms under pressure has a structure in which a central portion of the diaphragm is thinner than a peripheral portion. The heat-sensitive wave quantity detector according to claim 1 or 3.(5) The heating element is arranged in a thinned part of the diaphragm.(6) The heating element is arranged in the center of the diaphragm. A heat-sensitive wave quantity detector according to claim 5, characterized in that the heating element is embedded in a diaphragm as an impurity diffusion layer. Claim 2
．． 3, 4.5, or the heat-sensitive wave quantity detector according to any one of Item 6. (8) The heat-sensitive type according to any one of Claims 2.3, 4, 5.6, or 7, characterized in that the strain sensing element is an impurity diffusion layer and is embedded in the diaphragm. Wave quantity detector. (9) Claim 2, characterized in that the strain detection element is disposed in the thinned portion of the diaphragm.
3, 4.5, 6.7, or the heat-sensitive wave quantity detector according to any one of Item 8. The heat-sensitive type wave quantity detector according to claim 9, characterized in that the strain detection element is disposed around the periphery of the thinned portion of the diaphragm. ttn The heat-sensitive wave quantity detector according to claim 1, wherein the diaphragm that deforms under pressure is made of a metal material. 12. The heat-sensitive wave quantity detector according to claim 11, wherein the diaphragm that deforms in response to O3 pressure has a structure in which a central portion of the diaphragm is thinner than a peripheral portion. The heat-sensitive wave quantity detector according to claim 11 or 12, characterized in that the O3 heating element is attached to the diaphragm surface or not, and is arranged in the center of the diaphragm. . I. The heat-sensitive wave quantity detector according to claim 11, 12 or 13, characterized in that the strain detection element is bonded onto the diaphragm surface. (15) One surface of the pressure-deforming diaphragm is configured to receive the total pressure of the flowing fluid, the other surface is configured to receive the static pressure of the flowing fluid, and the dynamic pressure of the flowing fluid Claims 1.2.3.4.5.6, 7, and 1.2.3.4.5.6, 7.
8.9° 10.11, 12.13, or the heat-sensitive wave quantity detector according to any one of Item 14. ” Above 115

Claims (1)

[Scope of Claims] (1) In a heat-sensitive flow rate detector that detects the flow velocity or flow rate of a flowing fluid from the amount of heat transfer between a heating element and a flowing fluid, the cross-sectional area of the flowing fluid passage is narrowed. a diaphragm that is placed behind the flow speed increase means and deforms under pressure according to the flow speed of the flowing fluid; and a heating element that is embedded in or bonded to the diaphragm; A heat-sensitive flow rate detector comprising: a strain detection element embedded in or bonded to the diaphragm; and supporting means that supports a peripheral portion of the diaphragm and is made of a hot-glow defective conductor. (2) The heat-sensitive flow rate detector according to claim 1, wherein the diaphragm that deforms under pressure is made of a semiconductive material. (3) The heat-sensitive flow rate detector according to claim 2, wherein the diaphragm that deforms under pressure is made of silicone material. (4) A heat-sensitive flow rate detector according to claim 2 or 3, characterized in that the diaphragm that deforms under pressure has a structure in which a central portion of the diaphragm is thinner than a peripheral portion. (Claims 2 and 3 characterized in that the 51 heating element is arranged in the thinned part of the diaphragm.
Alternatively, the heat-sensitive flow rate detector according to any one of Item 4. (6) A heat-sensitive flow rate detector according to claim 5, characterized in that the heating element is disposed in the center of the diaphragm. (7) Claim 2, characterized in that the heating element has a structure in which the heating element is embedded in the diaphragm as an impurity diffusion layer.
．． 3. The heat-sensitive flow rate detector according to any one of Item 3, 4.5, or 6. (8) The heat-sensitive type according to any one of Claims 2.3, 4, 5.6, or 7, characterized in that the strain sensing element is an impurity diffusion layer and is embedded in the diaphragm. Flow rate detector. (9) Claim 2, characterized in that the strain detection element is disposed in the thinned portion of the diaphragm.
3, 4, 5, 6.7 or the heat-sensitive flow rate detector according to any one of Item 8. 10. The heat-sensitive flow rate detector according to claim 9, wherein the OI strain detection element is disposed around the periphery of the thinned portion of the diaphragm. 2. The heat-sensitive flow rate detector according to claim 1, wherein the diaphragm that deforms under Oυ pressure is made of a metal material. 112. The heat-sensitive flow rate detector according to claim 111, wherein the diaphragm that deforms under +13 pressure has a structure in which a central portion of the diaphragm is thinner than a peripheral portion. 13. A heat-sensitive flow rate detector according to claim 11 or 12, characterized in that the heating element is bonded on the diaphragm surface or not, and is disposed in the center of the diaphragm. (14) A heat-sensitive flow rate detector according to any one of claims 11, 12 and 13, characterized in that the strain detection element is bonded onto the diaphragm surface. αω One surface of the diaphragm that deforms under pressure is configured to receive the total pressure of the flowing fluid, and the other surface is configured to receive the static pressure of the flowing fluid, and the pressure is received by the dynamic pressure of the flowing fluid. Claims 1゜2.3, 4, 5, 6, 7, 8, characterized in that they are configured to be deformed.
9, 10, 11.12.13, or the heat-sensitive flow rate detector according to any one of Item 14.