JP6507804B2

JP6507804B2 - Air flow measuring device

Info

Publication number: JP6507804B2
Application number: JP2015077263A
Authority: JP
Inventors: 啓介板倉
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2015-04-03
Filing date: 2015-04-03
Publication date: 2019-05-08
Anticipated expiration: 2035-04-03
Also published as: JP2016196857A

Description

本発明は、エンジン（内燃機関）に吸い込まれる吸気の湿度を検出する湿度検出素子を搭載する空気流量測定装置に関する。 The present invention relates to an air flow measurement device equipped with a humidity detection element that detects the humidity of intake air drawn into an engine (internal combustion engine).

近年、車両の燃費向上や排気ガスのクリーン化の目的で、エンジンに吸い込まれる吸気の湿度を測定する要求が高まっている。
そこで、空気流量測定装置に湿度検出素子を搭載し、吸気流量とともに吸気湿度を測定する技術が提案されている（例えば、特許文献１参照）。 In recent years, there has been an increasing demand to measure the humidity of intake air sucked into an engine for the purpose of improving fuel efficiency of vehicles and cleaning exhaust gases.
Therefore, a technology has been proposed in which a humidity detection element is mounted on the air flow rate measuring device and the intake air flow rate and the intake air humidity are measured (see, for example, Patent Document 1).

空気流量測定装置が取り付けられる吸気ダクトや空気流量測定装置が、エンジンルーム内の熱を受けて温度が高まる可能性がある。
すると、吸気ダクトや空気流量測定装置の熱が、湿度検出素子を支持する部材（バイパスハウジング等）や電気的な接続手段（リード端子等）を介して湿度検出素子に伝わってしまう。 An air intake duct or an air flow measurement device to which the air flow measurement device is attached may receive heat in the engine room to increase its temperature.
Then, the heat of the air intake duct or the air flow rate measuring device is transmitted to the humidity detection element via a member (bypass housing etc.) supporting the humidity detection element or an electrical connection means (lead terminal etc.).

その結果、吸気ダクトの内部を通過する吸気の温度に比較して、湿度検出素子の温度が高くなる。このように、湿度検出素子の温度が、測定対象である吸気の温度と異なると、湿度検出素子によって吸気の湿度を正確に測定できなくなってしまう。 As a result, the temperature of the humidity detection element is higher than the temperature of the intake air passing through the inside of the intake duct. Thus, if the temperature of the humidity detection element is different from the temperature of the intake air to be measured, the humidity detection element can not accurately measure the humidity of the intake air.

特許第５４４５５３５号公報Patent No. 5445535 gazette

本発明は、上記問題点に鑑みてなされたものであり、その目的は、湿度検出素子の温度を吸気の温度に強制的に近づけて、吸気湿度の検出精度を高めることのできる空気流量測定装置の提供にある。 The present invention has been made in view of the above problems, and an object thereof is an air flow measuring device capable of forcibly bringing the temperature of the humidity detecting element close to the temperature of the intake air and enhancing the detection accuracy of the intake humidity. To provide.

本発明は、「湿度検出素子の温度」と「バイパスハウジングの近傍を流れる吸気の温度」とを放熱手段を用いて強制的に近づける。
これにより、湿度検出素子の温度を吸気ダクトの内部を通過する吸気の温度に近づけることができ、空気流量測定装置に設けた湿度検出素子によって吸気湿度の検出精度を高めることができる。 The present invention forcibly brings the "temperature of the humidity detection element" and the "the temperature of the intake air flowing in the vicinity of the bypass housing" close to each other using the heat dissipation means.
Thus, the temperature of the humidity detection element can be brought close to the temperature of the intake air passing through the inside of the intake duct, and the detection accuracy of the intake humidity can be enhanced by the humidity detection element provided in the air flow measuring device.

また、放熱手段によって、湿度検出素子の温度を吸気の温度に強制的に近づけることが可能になるため、湿度検出素子の搭載制約を抑えることが可能になる。即ち、放熱手段を設けることで、湿度検出素子を搭載する空気流量測定装置の構造的な自由度を高めることができる。 In addition, since the temperature of the humidity detection element can be forcibly brought close to the temperature of the intake air by the heat radiation means, it is possible to suppress the installation restriction of the humidity detection element. That is, by providing the heat dissipating means, it is possible to increase the structural freedom of the air flow measuring device having the humidity detecting element mounted thereon.

（ａ）吸気上流側から見た空気流量測定装置の概略図、（ｂ）吸気の流れ方向に沿う空気流量測定装置の概略断面図である（実施例１）。(A) Schematic of the air flow measurement apparatus seen from the intake upstream side, (b) It is a schematic sectional drawing of the air flow measurement apparatus along the flow direction of intake (Example 1). （ａ）湿度センサの外観図、（ｂ）湿度センサの長手方向に沿う断面図、（ｃ）湿度センサを長手方向に対して垂直方向へカットした断面図である（実施例１）。(A) An external view of a humidity sensor, (b) a sectional view along the longitudinal direction of the humidity sensor, (c) a sectional view obtained by cutting the humidity sensor in a direction perpendicular to the longitudinal direction (Example 1). 湿度センサの裏面側の外観図である（実施例２、３）。It is an external view of the back side of a humidity sensor (Example 2, 3). 湿度センサの長手方向に沿う断面図である（実施例４）。It is sectional drawing in alignment with the longitudinal direction of a humidity sensor (Example 4). 湿度センサの表面側の外観図である（実施例５）。It is an external view of the surface side of a humidity sensor (Example 5). 湿度センサの長手方向に沿う断面図である（実施例６）。It is sectional drawing in alignment with the longitudinal direction of a humidity sensor (Example 6). 湿度センサの長手方向に沿う断面図である（実施例７）。It is sectional drawing in alignment with the longitudinal direction of a humidity sensor (Example 7). 湿度センサの表面側の外観図である（実施例８）。It is an external view of the surface side of a humidity sensor (Example 8). 湿度センサの長手方向に沿う断面図である（実施例９）。It is sectional drawing in alignment with the longitudinal direction of a humidity sensor (Example 9). 吸気の流れ方向に沿う湿度センサの断面図である（実施例１０）。It is sectional drawing of the humidity sensor in alignment with the flow direction of inhalation | air-intake (Example 10). 吸気の流れ方向に沿う湿度センサの断面図である（実施例１１）。It is sectional drawing of the humidity sensor in alignment with the flow direction of inhalation | air-intake (Example 11).

以下において「発明を実施するための形態」を詳細に説明する。 Hereinafter, the “embodiments for carrying out the invention” will be described in detail.

本発明の具体的な一例（実施例）を図面に基づき説明する。なお、以下の「実施例」は具体的な一例を開示するものであり、本発明が「実施例」に限定されないことは言うまでもない。 A specific example (embodiment) of the present invention will be described based on the drawings. In addition, it is needless to say that the following "Example" discloses a specific example, and the present invention is not limited to the "Example".

［実施例１］
実施例１を図１、図２を参照して説明する。
空気流量測定装置は、車両走行用エンジンへ吸気（燃焼用の空気）を導く吸気ダクト１（エアクリーナのアウトレットや吸気管等）に搭載されるものであり、少なくともエンジンに吸い込まれる吸気流量（空気流量）の測定を行う。 Example 1
Example 1 will be described with reference to FIGS. 1 and 2.
The air flow measuring device is mounted on an intake duct 1 (such as an outlet of an air cleaner or an intake pipe) for guiding intake air (air for combustion) to a vehicle running engine, and at least an intake flow rate (air flow rate) sucked into the engine Make a measurement of

吸気ダクト１において空気流量測定装置が搭載される箇所には、吸気ダクト１の内外を貫通する装着穴が形成されており、空気流量測定装置には装着穴を閉塞するための蓋部２が設けられている。 A mounting hole is formed in a portion of the intake duct 1 where the air flow measuring device is mounted, the mounting hole penetrating the inside and the outside of the intake duct 1, and the air flow measuring device is provided with a lid 2 for closing the mounting hole. It is done.

具体的に、空気流量測定装置は、
・蓋部２と一体的に設けられるバイパスハウジング３と、
・このバイパスハウジング３の内部に設けられる流量センサ４と、
を備える。 Specifically, the air flow measuring device
· A bypass housing 3 provided integrally with the lid portion 2;
A flow rate sensor 4 provided inside the bypass housing 3;
Equipped with

上述したように、吸気ダクト１には装着穴が形成されており、この装着穴の外部よりバイパスハウジング３を吸気ダクト１内に挿入した後、蓋部２によって装着穴を閉塞する。そして、蓋部２をタッピングスクリュ等の固定手段を用いて吸気ダクト１に固定することで吸気ダクト１に空気流量測定装置が組付けられる。 As described above, the mounting hole is formed in the air intake duct 1, and after the bypass housing 3 is inserted into the air intake duct 1 from the outside of the mounting hole, the mounting hole is closed by the lid 2. Then, the lid 2 is fixed to the intake duct 1 using fixing means such as a tapping screw, whereby the air flow measuring device is assembled to the intake duct 1.

バイパスハウジング３は、内部に通路を形成する通路形成部材であり、樹脂材料によって設けられる。バイパスハウジング３の内部に形成される通路の構造は限定するものではないが、具体的な一例としてこの実施例では、バイパスハウジング３の内部に、吸気ダクト１の内部（主空気通路）を流れる吸気の一部が通過するバイパス通路５（副空気通路）とサブバイパス通路６（副々空気通路）を設けている。 The bypass housing 3 is a passage forming member that forms a passage in the inside, and is provided by a resin material. Although the structure of the passage formed inside the bypass housing 3 is not limited, as a specific example, in this embodiment, the intake air flowing through the inside of the intake duct 1 (main air passage) inside the bypass housing 3 A bypass passage 5 (sub air passage) and a sub bypass passage 6 (sub air passage) through which part of the air passage passes are provided.

バイパス通路５は、吸気ダクト１内を流れる空気の一部が通過する空気通路であり、吸気ダクト１における吸気の流れ方向に沿うように通路が形成される。そして、バイパス通路５の吸気上流側に空気取入口５ａが設けられ、バイパス通路５の吸気下流側に空気排出口５ｂが設けられる。なお、空気排出口５ｂには、バイパス通路５を通過する空気流を絞るための出口絞りが形成される。 The bypass passage 5 is an air passage through which a part of the air flowing in the intake duct 1 passes, and a passage is formed along the flow direction of the intake air in the intake duct 1. An air intake port 5 a is provided on the intake upstream side of the bypass passage 5, and an air exhaust port 5 b is provided on the intake downstream side of the bypass passage 5. An outlet throttle for throttling the air flow passing through the bypass passage 5 is formed in the air outlet 5b.

サブバイパス通路６は、出口絞り（空気排出口５ｂ）で絞られたバイパス通路５の空気流の一部が流入する入口６ａと、サブバイパス通路６を通過した空気流を吸気ダクト１内へ戻す出口６ｂとを備え、入口６ａから流入した空気をバイパスハウジング３の内部で回転させて吸気ダクト１内へ戻す迂回路を形成するものである。
なお、図１では、サブバイパス通路６の出口６ｂをバイパス通路５の外部に設けているが、限定するものではなく、例えばサブバイパス通路６の出口６ｂをバイパス通路５内に開口させて、サブバイパス通路６を通過した空気流を再びバイパス通路５内に戻すものであっても良い。 The sub-bypass passage 6 returns the air flow passing through the sub-bypass passage 6 back into the intake duct 1 at the inlet 6a where a part of the airflow of the bypass passage 5 narrowed by the outlet throttle (air outlet 5b) flows. An outlet 6 b is provided to form a bypass path in which the air flowing in from the inlet 6 a is rotated inside the bypass housing 3 and returned into the intake duct 1.
Although the outlet 6b of the sub bypass passage 6 is provided outside the bypass passage 5 in FIG. 1, it is not limited. For example, the outlet 6b of the sub bypass passage 6 is opened in the bypass passage 5 to The air flow passing through the bypass passage 6 may be returned to the bypass passage 5 again.

バイパスハウジング３と一体に設けられる蓋部２には、ＥＣＵ（エンジン・コントロール・ユニット）接続用のコネクタ７が設けられており、蓋部２とバイパスハウジング３は共通の樹脂材料によって設けられる。 The lid 2 integrally provided with the bypass housing 3 is provided with a connector 7 for connecting an ECU (engine control unit), and the lid 2 and the bypass housing 3 are provided by a common resin material.

流量センサ４は、熱の検出値に基づいてサブバイパス通路６の内部を通過する吸気流量を測定する周知な熱式であり、具体的な構成は限定するものではなく、チップ型（薄膜式の基板型）を採用するものであっても良いし、ボビン型抵抗体（単品型の抵抗体）を採用するものであっても良い。 The flow rate sensor 4 is a well-known thermal type that measures the intake flow rate passing through the inside of the sub bypass passage 6 based on the detected value of heat, and the specific configuration is not limited. A substrate type may be employed, or a bobbin type resistor (single component type resistor) may be employed.

具体的な一例として、図１（ｂ）に示す流量センサ４は、アッシー化された状態でパイバスハウジング３の内部に配置されるチップ型であり、
・吸気流量を測定する流量検出部８ａが設けられるセンサ基板８と、
・コネクタ７を介して電気的に接続される流量センサ回路９と、
・この流量センサ回路９を収容する回路ハウジング１０と、
を備える。
なお、流量センサ回路９は、流量検出部８ａで検出した流量を吸気の温度（発熱ヒータにより加熱されていない吸気温度）で補正し、補正後の流量信号をデジタル信号化（例えば、周波数変調）して出力するように設けられている。 As a specific example, the flow rate sensor 4 shown in FIG. 1 (b) is a chip type that is disposed inside the pie bus housing 3 in an assembled state,
A sensor substrate 8 provided with a flow rate detection unit 8a that measures an intake flow rate;
A flow rate sensor circuit 9 electrically connected via a connector 7;
A circuit housing 10 that accommodates the flow sensor circuit 9;
Equipped with
The flow rate sensor circuit 9 corrects the flow rate detected by the flow rate detection unit 8a with the temperature of the intake air (intake air temperature not heated by the heating heater), and digitizes the corrected flow rate signal (for example, frequency modulation) Are provided to output.

（吸気温度センサ１１の説明）
この実施例の空気流量測定装置は、吸気ダクト１内を通過する吸気の温度（エンジンに吸い込まれる吸気の温度）を測定する吸気温度センサ１１を備える。
この実施例の吸気温度センサ１１は、図１に示すように、バイパスハウジング３の外部に配置されて、バイパスハウジング３の外部を通過する吸気の温度を測定する。具体的に、吸気温度センサ１１は、バイパスハウジング３の伝熱影響を極力受けないように、吸気温度センサ１１がバイパスハウジング３から所定量離れた中空に配置される。 (Description of intake air temperature sensor 11)
The air flow measurement device of this embodiment includes an intake air temperature sensor 11 that measures the temperature of intake air passing through the intake duct 1 (temperature of intake air taken into the engine).
As shown in FIG. 1, the intake air temperature sensor 11 of this embodiment is disposed outside the bypass housing 3 to measure the temperature of intake air passing through the outside of the bypass housing 3. Specifically, the intake air temperature sensor 11 is disposed in a hollow space separated by a predetermined amount from the bypass housing 3 so that the intake air temperature sensor 11 is not affected by the heat transfer of the bypass housing 3 as much as possible.

図１（ａ）に示す吸気温度センサ１１は、ボビン型の抵抗体形状を呈するサーミスタ素子であり、温度によって抵抗値が変化するサーミスタ本体と、このサーミスタ本体から延びる２本のリード線とを備える。そして、２本のリード線が蓋部２またはバイパスハウジング３によって支持されることで、サーミスタ本体がバイパスハウジング３から所定量離れた中空にて支持される。
なお、吸気温度センサ１１の測定した吸気温度信号（吸気温度に応じた信号）は、抵抗値変化を電圧として取り出しても良いし、吸気流量と同様、デジタル信号化（例えば、周波数変調）して出力させても良い。 The intake air temperature sensor 11 shown in FIG. 1A is a thermistor element in the form of a bobbin type resistor, and includes a thermistor body whose resistance value changes with temperature, and two lead wires extending from the thermistor body. . The two lead wires are supported by the lid 2 or the bypass housing 3 so that the thermistor body is supported in the hollow separated from the bypass housing 3 by a predetermined amount.
The intake air temperature signal (a signal corresponding to the intake air temperature) measured by the intake air temperature sensor 11 may take out a change in resistance value as a voltage, or may be digitized (for example, frequency modulation) as in the intake air flow rate. You may output it.

（湿度センサ１２の説明）
湿度センサ１２の具体例を、図１、図２を参照して説明する。
なお、以下では、説明のための便宜上、図１における吸気ダクト１の上下方向を「ｘ軸方向」、図１における吸気ダクト１の左右方向を「ｙ軸方向」、吸気ダクト１の中心軸に沿う方向（バイパスハウジング３の外部を流れる吸気の流れ方向）を「ｚ軸方向」として説明する。 (Description of humidity sensor 12)
A specific example of the humidity sensor 12 will be described with reference to FIGS. 1 and 2.
In the following, for convenience of explanation, the vertical direction of the intake duct 1 in FIG. 1 is “x-axis direction”, the lateral direction of the intake duct 1 in FIG. 1 is “y-axis direction”, and the central axis of the intake duct 1 is The direction (the flow direction of the intake air flowing outside the bypass housing 3) will be described as the "z-axis direction".

また、この実施例の湿度センサ１２は、後述するように断面が略矩形の平板形状を呈するものであり（限定しない）、以下では、説明のための便宜上、湿度センサ１２において最も長い辺が伸びる方向｛図２（ｂ）の上下方向｝を「ｘ’軸方向」、湿度センサ１２において最も短い辺が伸びる方向｛図２（ｂ）の左右方向｝を「ｙ’軸方向」、湿度センサ１２において２番目に長い辺が伸びる方向｛図２（ｃ）の左右方向｝を「ｚ’軸方向」と称する。 Further, the humidity sensor 12 of this embodiment has a flat plate shape (without limitation) having a substantially rectangular cross section as will be described later, and in the following, the longest side of the humidity sensor 12 extends for convenience of description. Direction {vertical direction in FIG. 2 (b)} is “x 'axis direction”, direction in which the shortest side extends in the humidity sensor 12 {horizontal direction in FIG. 2 (b)} is “y' axis direction”, humidity sensor 12 The direction in which the second longest side extends in {right and left direction in FIG. 2 (c)} is referred to as the “z ′ axis direction”.

空気流量測定装置は、吸気ダクト１内を通過する吸気の湿度（エンジンに吸い込まれる吸気の湿度）を測定する湿度センサ１２を備える。
この実施例の湿度センサ１２は、図１（ａ）に示すように、バイパスハウジング３の外部（請求項２の近傍の一例）に配置されて、バイパスハウジング３の外部（請求項１の近傍の一例）を通過する吸気の湿度を測定する。
具体的に、湿度センサ１２は、バイパスハウジング３の伝熱影響（具体的には、蓋部２を介してバイパスハウジング３に伝わった熱の影響）を極力受けないように、湿度センサ１２がバイパスハウジング３から所定量離れた部位に配置される。 The air flow measurement device includes a humidity sensor 12 that measures the humidity of intake air passing through the intake duct 1 (the humidity of intake air drawn into the engine).
The humidity sensor 12 of this embodiment, as shown in FIG. 1A, is disposed outside the bypass housing 3 (an example near the claim 2) and outside the bypass housing 3 (around the claim 1). Measure the humidity of the intake air passing through
Specifically, the humidity sensor 12 is bypassed so that the humidity sensor 12 is not affected as much as possible by the heat transfer of the bypass housing 3 (specifically, the influence of the heat transmitted to the bypass housing 3 via the lid 2). It is disposed at a position separated from the housing 3 by a predetermined amount.

さらに具体的に説明すると、この実施例の湿度センサ１２は、湿度センサ１２のｘ’軸方向が吸気ダクト１のｘ軸方向と平行に配置され、湿度センサ１２のｙ’軸方向が吸気ダクト１のｙ軸方向と平行に配置され、湿度センサ１２のｚ’軸方向が吸気ダクト１のｚ軸方向と平行に配置される。
即ち、湿度センサ１２における幅広の面（表面と裏面）が、吸気の流れ方向に対して平行に配置される。 More specifically, in the humidity sensor 12 of this embodiment, the x'-axis direction of the humidity sensor 12 is disposed parallel to the x-axis direction of the intake duct 1, and the y'-axis direction of the humidity sensor 12 is the intake duct 1 The z'-axis direction of the humidity sensor 12 is disposed parallel to the z-axis direction of the intake duct 1.
That is, the wide surfaces (front and back) of the humidity sensor 12 are disposed parallel to the flow direction of the intake air.

湿度センサ１２の具体的な構造を説明する。
湿度センサ１２は、
・バイパスハウジング３の外部を通過する吸気の湿度を測定する湿度検出素子１３と、
・湿度検出素子１３の湿度信号を外部へ向けて出力する湿度センサ回路１４と、
・この湿度検出素子１３や湿度センサ回路１４を搭載する回路基板１５と、
・バイパスハウジング３の外部を流れる吸気に直接触れるとともに、湿度検出素子１３および湿度センサ回路１４と薄い回路基板１５を介して熱結合する金属製の放熱プレート１６（放熱手段の一例）と、
・蓋部２に設けられるコネクタ７内に一部が露出配置される（または、蓋部２内で流量センサ回路９とターミナルを介して接続される）複数のリード端子１７（吸気ダクト１の壁面に近い側に設けられる金属製の電気接続手段の一例）と、
・湿度センサ１２の構成部品（湿度検出素子１３、放熱プレート１６等）を樹脂によってモールドするモールド樹脂１８と、
を備えて構成される。
なお、熱結合は、熱的な結合であり、湿度検出素子１３と放熱プレート１６は薄い回路基板１５（即ち、伝達をほとんど妨げない回路基板１５）を介してほぼ直接的に熱のやりとりを行うように設けられている。 The specific structure of the humidity sensor 12 will be described.
Humidity sensor 12 is
A humidity detection element 13 for measuring the humidity of intake air passing through the outside of the bypass housing 3;
A humidity sensor circuit 14 that outputs the humidity signal of the humidity detection element 13 to the outside and
A circuit board 15 on which the humidity detection element 13 or the humidity sensor circuit 14 is mounted,
A metal heat dissipating plate 16 (an example of a heat dissipating means) thermally coupled to the humidity detecting element 13 and the humidity sensor circuit 14 via the thin circuit board 15 while directly touching the intake air flowing outside the bypass housing 3;
· A plurality of lead terminals 17 (parts of the wall surface of the intake duct 1 are exposed exposed in the connector 7 provided in the lid 2 (or connected with the flow rate sensor circuit 9 in the lid 2 via a terminal) An example of a metal electrical connection means provided on the side close to
A mold resin 18 for molding the components of the humidity sensor 12 (the humidity detection element 13, the heat radiation plate 16 and the like) with a resin;
It is configured with.
The thermal coupling is a thermal coupling, and the humidity detection element 13 and the heat radiation plate 16 exchange heat almost directly via the thin circuit board 15 (that is, the circuit board 15 which hardly hinders the transmission) It is provided as.

湿度検出素子１３は、周知の静電容量式であり、具体的な構成は限定するものではなく、例えば、市販の湿度検出用ＩＣ等を採用している。
湿度検出用ＩＣの具体的な構造の一例は、
・触れる空気の相対湿度に応じて静電容量が変化する湿度検出部と、
・静電容量の変化を湿度信号（電圧信号）に変換する増幅部と、
・湿度信号を環境温度に基づいて補正し、補正後の湿度信号を出力する補正回路と、
を一体化したものである。 The humidity detection element 13 is a well-known electrostatic capacitance type, and the specific configuration is not limited. For example, a commercially available humidity detection IC or the like is adopted.
An example of a specific structure of the humidity detection IC is
-A humidity detection unit whose capacitance changes in accordance with the relative humidity of the air to be touched,
An amplification unit that converts a change in capacitance into a humidity signal (voltage signal);
· A correction circuit that corrects the humidity signal based on the environmental temperature and outputs the corrected humidity signal,
Is integrated.

湿度センサ回路１４は、湿度検出素子１３の出力する湿度信号を、流量信号や吸気温度信号と同様、周波数変調した後にＥＣＵへ出力するものであり（一例であり、限定しない）、複数の電気部品類（コンデンサや抵抗体等）によって設けられる。 The humidity sensor circuit 14 performs frequency modulation on the humidity signal output from the humidity detection element 13 as well as the flow rate signal and the intake air temperature signal, and then outputs the signal to the ECU (an example is not limited). It is provided by the kind (a capacitor, a resistor, etc.).

回路基板１５は、湿度検出素子１３や湿度センサ回路１４の搭載面のみに導電性のプリント配線（プリントパターン）がプリントされた樹脂等よりなる薄く可撓性を備える絶縁膜であり、プリント配線は湿度検出素子１３や湿度センサ回路１４を構成する電気部品類と電気的に接続される。
回路基板１５は、ｘ’軸方向へ長く伸びる長方形状を呈しており、湿度検出素子１３は、湿度センサ１２を支持する蓋部２から遠い側（吸気ダクト１の中心に近い側）の回路基板１５に搭載される。また、湿度センサ回路１４は、蓋部２と湿度検出素子１３との間の回路基板１５に搭載される。 The circuit board 15 is a thin and flexible insulating film made of a resin or the like on which a conductive printed wiring (print pattern) is printed only on the mounting surface of the humidity detecting element 13 or the humidity sensor circuit 14. It is electrically connected to the humidity detection element 13 and the electric components constituting the humidity sensor circuit 14.
The circuit board 15 has a rectangular shape extending in the x 'axis direction, and the humidity detection element 13 is a circuit board on the side far from the lid 2 supporting the humidity sensor 12 (side closer to the center of the intake duct 1) It will be mounted on 15. Further, the humidity sensor circuit 14 is mounted on the circuit board 15 between the lid 2 and the humidity detection element 13.

放熱プレート１６は、湿度検出素子１３の裏面（湿度検出素子１３において吸気に直接触れる面を表面とした場合、表面とは反対の面が裏面）と回路基板１５を介して熱結合する樹脂より放熱性が高い板材あり、伝熱性に優れた金属等（例えば、アルミニウムや銅等）によって設けられる。
この放熱プレート１６は、ｘ’軸方向とｙ’軸方向が回路基板１５の略同じ寸法に設けられたｘ’軸方向に長く伸びる長方形の平板であり、放熱プレート１６の厚み寸法（ｙ’軸方向の寸法）は、放熱プレート１６の熱抵抗を小さくする目的で適度な厚み（少なくとも０．５ｍｍ以上、好ましくは０．８ｍｍ以上、より好ましくは１ｍｍ以上）が確保される。 The heat dissipation plate 16 dissipates heat from the resin thermally coupled via the circuit board 15 with the back surface of the humidity detection element 13 (when the surface directly in contact with intake air in the humidity detection element 13 is the surface opposite to the front surface) It is a plate material with high property, and is provided by metal etc. (for example, aluminum, copper etc.) excellent in heat conductivity.
The heat dissipating plate 16 is a rectangular flat plate elongated in the x′-axis direction, in which the x′-axis direction and the y′-axis direction are substantially the same dimensions as the circuit board 15. In order to reduce the thermal resistance of the heat dissipation plate 16, an appropriate thickness (at least 0.5 mm or more, preferably 0.8 mm or more, more preferably 1 mm or more) is secured for the dimension of the direction.

放熱プレート１６の裏面（回路基板１５の搭載面とは反対の面）の略全面は、モールド樹脂１８の外部に露出するものであり、放熱プレート１６の裏面の略全面がバイパスハウジング３の外部を流れる吸気と直接触れるように設けられる。
また、放熱プレート１６は、回路基板１５を支持する支持プレートを兼ねるものであり、放熱プレート１６と回路基板１５は、接着剤等により結合された状態でモールド樹脂１８にモールドされる（一例であり、限定しない）。 The substantially entire surface of the back surface of the heat dissipation plate 16 (the surface opposite to the mounting surface of the circuit board 15) is exposed to the outside of the mold resin 18, and the substantially entire surface of the back surface of the heat dissipation plate 16 is the outside of the bypass housing 3 Directly in contact with the flowing air.
The heat dissipating plate 16 also serves as a support plate for supporting the circuit board 15. The heat dissipating plate 16 and the circuit board 15 are molded on the mold resin 18 in a state of being bonded by an adhesive or the like (an example) , Not limited).

各リード端子１７は、導電性の薄板金属をプレス加工によって切断形成した長細い金属片であり（一例であり、限定しない）、それぞれのリード端子１７は、回路基板１５のプリント配線とワイヤボンディング１９を介して電気的に接続される。
回路基板１５のプリント配線と電気的に接続された後のリード端子１７は、一部が外部に露出した状態でモールド樹脂１８にモールドされる。
また、モールド樹脂１８の外部に露出したリード端子１７は、蓋部２と一体に設けられるコネクタ７の内部に配置されるか、あるいは蓋部２内で流量センサ回路９と接続される。 Each lead terminal 17 is a long thin metal piece formed by cutting a conductive thin plate metal by press work (an example is not limited), and each lead terminal 17 is a printed wiring of the circuit board 15 and wire bonding 19 Are electrically connected via
The lead terminals 17 after being electrically connected to the printed wiring of the circuit board 15 are molded in the mold resin 18 in a state where a part thereof is exposed to the outside.
Further, the lead terminal 17 exposed to the outside of the mold resin 18 is disposed inside the connector 7 integrally provided with the lid 2 or connected to the flow sensor circuit 9 in the lid 2.

モールド樹脂１８は、上述したように、湿度センサ１２を構成する部品類をモールドする絶縁性の樹脂であり、湿度センサ１２を構成する部品類を保護するとともに、湿度センサ１２の剛性を確保するものである。
このモールド樹脂１８には、湿度検出素子１３の一部（具体的には、上述した湿度検出部）に吸気を直接導く窓部１８ａが設けられている。
また、モールド樹脂１８には、放熱プレート１６の裏面の略全面を吸気に晒す放熱開口１８ｂが設けられている。 As described above, the mold resin 18 is an insulating resin that molds the components that make up the humidity sensor 12, protects the components that make up the humidity sensor 12, and ensures the rigidity of the humidity sensor 12. It is.
The mold resin 18 is provided with a window 18 a for directly leading the intake air to a part of the humidity detection element 13 (specifically, the above-described humidity detection unit).
Further, the mold resin 18 is provided with a heat radiation opening 18 b for exposing substantially the entire surface of the back surface of the heat radiation plate 16 to the intake air.

モールド樹脂１８の長手方向の一端（図１の上側）は、蓋部２を成す樹脂材料にモールドされるものであり、蓋部２にモールド樹脂１８がモールドされることで、空気流量測定装置に湿度センサ１２が支持される。
なお、この実施例では、図１（ａ）に示すように、湿度検出素子１３の表面（吸気に直接触れる面）がバイパスハウジング３に対向して配置され、放熱プレート１６の裏面（吸気に直接触れる面）がバイパスハウジング３とは異なる方向に向くように配置される例を示すが、限定するものではなく、例えば逆であっても良い。
また、この実施例のモールド樹脂１８は、図２（ｃ）に示すように、断面が略矩形形状を呈するものであるが、もちろん限定するものではなく、湿度センサ１２の空気抵抗を減らす目的で、モールド樹脂１８の上流端と下流端を流線形に設けても良く、モールド樹脂１８の上流端と下流端を尖らせても良い。 One end (upper side in FIG. 1) of the mold resin 18 in the longitudinal direction is molded on the resin material forming the lid 2, and the mold resin 18 is molded on the lid 2 to make the air flow measuring device The humidity sensor 12 is supported.
In this embodiment, as shown in FIG. 1 (a), the surface of the humidity detection element 13 (the surface directly in contact with the intake air) is disposed opposite to the bypass housing 3, and the back surface of the heat dissipating plate 16 (directly An example is shown in which the touching surface is arranged to face in a direction different from that of the bypass housing 3, but this is not a limitation, and may be reversed, for example.
Further, as shown in FIG. 2C, although the mold resin 18 of this embodiment exhibits a substantially rectangular shape in cross section, it is of course not limited and for the purpose of reducing the air resistance of the humidity sensor 12. The upstream end and the downstream end of the mold resin 18 may be streamlined, and the upstream end and the downstream end of the mold resin 18 may be sharpened.

（実施例１の効果１）
空気流量測定装置に搭載される湿度センサ１２は、「湿度検出素子１３」と「バイパスハウジング３の外部を流れる空気」とを、放熱プレート１６を介して強制的に熱交換する構成を採用する。
これにより、エンジンルーム内の熱を吸気ダクト１や蓋部２が受熱した状態であっても、「湿度検出素子１３の温度」を「バイパスハウジング３の外部を流れる吸気の温度（吸気ダクト１から離れた吸気の温度：即ち、エンジンルームの熱影響を受けていない吸気の温度）」に極めて近づけることができる。このため、例えエンジンルーム内が高温の環境下であったとしても、吸気湿度の検出精度の劣化を防ぐことができ、空気流量測定装置に搭載した湿度センサ１２によって吸気の湿度を高精度に測定することができる。 (Effect 1 of Example 1)
The humidity sensor 12 mounted on the air flow measuring device adopts a configuration in which heat exchange between the “humidity detection element 13” and “air flowing outside the bypass housing 3” is forcibly performed via the heat dissipation plate 16.
As a result, even if the intake duct 1 and the cover 2 receive heat in the engine room, the "temperature of the humidity detection element 13" is set to "the temperature of the intake air flowing outside the bypass housing 3 (from the intake duct 1 "The temperature of the remote intake air: that is, the temperature of the intake not affected by the heat of the engine room)." For this reason, even if the inside of the engine room is in a high temperature environment, it is possible to prevent the deterioration of the detection accuracy of the intake humidity, and the humidity sensor 12 mounted on the air flow measuring device measures the humidity of the intake with high accuracy. can do.

（実施例１の効果２）
この実施例の湿度センサ１２は、上述したように、ｘ’軸方向に長く伸びて設けられる。また、放熱プレート１６もｘ’軸方向に長く伸びて吸気に直接触れるように設けられる。
これにより、蓋部２から湿度センサ１２に伝わる熱は、湿度検出素子１３に伝わる前に、蓋部２と湿度検出素子１３との間の区間において確実に放熱される。
このため、「湿度検出素子１３の温度」を「バイパスハウジング３の外部を流れる吸気の温度」に極めて近づけることができ、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 (Effect 2 of Example 1)
As described above, the humidity sensor 12 of this embodiment is provided to extend in the x 'axis direction. Further, the heat dissipating plate 16 is also provided so as to extend long in the x 'axis direction and to directly contact the intake air.
Thus, the heat transmitted from the lid 2 to the humidity sensor 12 is reliably dissipated in the section between the lid 2 and the humidity detecting element 13 before being transmitted to the humidity detecting element 13.
Therefore, "the temperature of the humidity detection element 13" can be made extremely close to "the temperature of the intake air flowing outside the bypass housing 3", and the detection accuracy of the humidity by the humidity sensor 12 can be more reliably enhanced.

（実施例１の効果３）
この実施例の湿度センサ１２は、湿度センサ回路１４が作動に伴って熱を発生する場合であっても、湿度センサ回路１４が発生した熱を、放熱プレート１６を介して放熱することができる。このため、湿度センサ回路１４の発生した熱によって湿度検出素子１３の温度が上昇する不具合を回避することができ、湿度センサ回路１４の発熱によって湿度センサ１２の検出精度が劣化する不具合を回避できる。 (Effect 3 of Example 1)
The humidity sensor 12 of this embodiment can dissipate the heat generated by the humidity sensor circuit 14 through the heat radiation plate 16 even when the humidity sensor circuit 14 generates heat as it operates. Therefore, the problem that the temperature of the humidity detection element 13 rises due to the heat generated by the humidity sensor circuit 14 can be avoided, and the problem that the detection accuracy of the humidity sensor 12 is deteriorated due to the heat generation of the humidity sensor circuit 14 can be avoided.

［実施例２］
実施例２を図３に基づき説明する。なお、以下の各実施例において上記実施例１と同一符号は同一機能物を示すものである。
この実施例２の放熱プレート１６には、モールド樹脂１８の外部に突出して吸気との接触面積を拡大する突出部１６ｄが設けられる。
突出部１６ｄの形状等は限定するものではないが、具体的な一例としてこの実施例２の突出部１６ｄは、放熱プレート１６のｘ’軸方向の長さ寸法を、モールド樹脂１８のｘ’軸方向の長さ寸法より長く設けて、放熱プレート１６の先端を吸気ダクト１の中心方向に延伸させたものである。 Example 2
A second embodiment will be described based on FIG. In the following embodiments, the same reference numerals as those in the first embodiment indicate the same functions.
The heat dissipating plate 16 according to the second embodiment is provided with a protrusion 16 d which protrudes to the outside of the mold resin 18 to enlarge the contact area with the intake air.
The shape and the like of the projecting portion 16 d are not limited, but as a specific example, the projecting portion 16 d of the second embodiment corresponds to the length dimension of the heat dissipating plate 16 in the x ′ axis direction. The tip of the heat dissipation plate 16 is extended in the central direction of the intake duct 1 so as to be longer than the longitudinal dimension of the direction.

突出部１６ｄを設けることで、放熱プレート１６の放熱性能を高めることができる。
特に、この実施例２では、突出部１６ｄを吸気ダクト１の中心方向に近づけているため、吸気ダクト１を通過する吸気のうち、最もエンジンルームからの受熱を受けにくい吸気の熱を吸気検出素子に伝えることができる。
このように、湿度検出素子１３の温度を、最もエンジンルームからの受熱を受けにくい吸気の温度に近づけることができるため、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 By providing the protrusion 16 d, the heat dissipation performance of the heat dissipation plate 16 can be enhanced.
In particular, in the second embodiment, since the protrusion 16 d is brought close to the center direction of the intake duct 1, the intake heat that is the least likely to receive heat from the engine room among the intake air passing through the intake duct 1 is an intake detection element Can tell.
As described above, since the temperature of the humidity detection element 13 can be brought close to the temperature of the intake air that is the least likely to receive heat from the engine room, the detection accuracy of the humidity by the humidity sensor 12 can be more reliably enhanced.

［実施例３］
実施例３を図３に基づき説明する。
この実施例３の放熱プレート１６には、「蓋部２に近い側（湿度検出素子１３よりも吸気ダクト１の壁面に近い側の一例）」と「湿度検出素子１３と熱結合する箇所」との間に、放熱プレート１６におけるｘ’軸方向の伝熱を妨げる切欠部または開口部よりなる肉抜き部１６ｃが設けられる。 [Example 3]
A third embodiment will be described based on FIG.
In the heat dissipating plate 16 of the third embodiment, "the side closer to the lid 2 (an example closer to the wall surface of the intake duct 1 than the humidity detection element 13)" and "the point thermally coupled to the humidity detection element 13" A lightening portion 16 c is formed between the heat dissipating plate 16 and a notch or an opening that impedes heat transfer in the x ′ axial direction.

このように設けることで、エンジンルーム内の熱を蓋部２が受熱し、蓋部２の熱が放熱プレート１６の端部（ワイヤボンディング１９が成される箇所の回路基板１５を支持する部分）に伝えられても、その熱が肉抜き部１６ｃにより遮断されるため、蓋部２の熱が放熱プレート１６を介して湿度検出素子１３に伝わるのを防ぐことができる。これにより、湿度検出素子１３の温度をより確実に吸気の温度に近づけることができ、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 By providing in this way, the lid 2 receives heat in the engine room, and the heat of the lid 2 is the end of the heat dissipation plate 16 (the part supporting the circuit board 15 at the place where the wire bonding 19 is formed) Since the heat is blocked by the lightening portion 16c, the heat of the lid 2 can be prevented from being transmitted to the humidity detection element 13 through the heat radiation plate 16. As a result, the temperature of the humidity detection element 13 can be more reliably brought close to the temperature of the intake air, and the detection accuracy of the humidity by the humidity sensor 12 can be more reliably improved.

［実施例４］
実施例４を図４に基づき説明する。
この実施例４の湿度センサ１２には、湿度検出素子１３よりも吸気ダクト１の壁面に近い側のモールド樹脂１８に、モールド樹脂１８の厚み寸法（ｙ’軸方向の寸法）を、他の箇所に比較して縮小する縮小部αが設けられる。
即ち、この実施例４の湿度センサ１２は、縮小部αによる温度抵抗が大きい箇所を、湿度検出素子１３よりも吸気ダクト１の壁面に近い側に設けたものである。 Example 4
A fourth embodiment will be described based on FIG.
In the humidity sensor 12 of the fourth embodiment, the mold resin 18 on the side closer to the wall surface of the intake duct 1 than the humidity detection element 13 has the thickness dimension (dimension in the y ′ axis direction) of the mold resin 18 A reduction unit α is provided to reduce the size of the image.
That is, in the humidity sensor 12 of the fourth embodiment, a portion where the temperature resistance due to the reduction portion α is large is provided closer to the wall surface of the intake duct 1 than the humidity detection element 13.

このように設けることで、エンジンルーム内の熱を蓋部２が受熱した状態であっても、蓋部２から湿度検出素子１３に伝わるのを、縮小部α（温度抵抗の大きい箇所）によって抑えることができる。これにより、湿度検出素子１３の温度をより確実に吸気の温度に近づけることができるため、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 By providing in this manner, even if the heat in the engine room is received by the cover 2, the reduction part α (a part having a large temperature resistance) suppresses transmission of heat from the cover 2 to the humidity detection element 13 be able to. As a result, the temperature of the humidity detection element 13 can be more reliably brought close to the temperature of the intake air, so that the detection accuracy of the humidity by the humidity sensor 12 can be more reliably improved.

［実施例５］
実施例５を図５に基づき説明する。
この実施例５の湿度センサ１２には、湿度検出素子１３よりも吸気ダクト１の壁面に近い側のモールド樹脂１８に、モールド樹脂１８の幅寸法（ｚ’軸方向の寸法）を、他の箇所に比較して縮小する縮小部αが設けられる。
即ち、この実施例５の湿度センサ１２は、上記実施例４と同様、縮小部αによる温度抵抗が大きい箇所を、湿度検出素子１３よりも吸気ダクト１の壁面に近い側に設けたものである。
このように設けることで、上記実施例４と同様の効果を得ることができる。 [Example 5]
A fifth embodiment will be described based on FIG.
In the humidity sensor 12 of the fifth embodiment, the width dimension (dimension in the z 'axis direction) of the mold resin 18 is added to the mold resin 18 on the side closer to the wall surface of the intake duct 1 than the humidity detection element 13 A reduction unit α is provided to reduce the size of the image.
That is, as in the fourth embodiment, the humidity sensor 12 according to the fifth embodiment is provided with a portion where the temperature resistance due to the reduction portion α is larger on the side closer to the wall surface of the intake duct 1 than the humidity detection element 13 .
By providing in this manner, the same effect as that of the fourth embodiment can be obtained.

［実施例６］
実施例６を図６に基づき説明する。
この実施例６の湿度センサ１２には、回路基板１５および放熱プレート１６と、複数のリード端子１７（吸気ダクト１の壁面に近い側に設けられる金属製の電気接続手段の一例）との間に、伝熱を阻害する熱抵抗体２２が設けられる。
熱抵抗体２２は、リード端子１７や放熱プレート１６を成す金属より熱伝導率の低いセラミック等の絶縁部材である。 [Example 6]
A sixth embodiment will be described based on FIG.
In the humidity sensor 12 according to the sixth embodiment, between the circuit board 15 and the heat radiation plate 16 and the plurality of lead terminals 17 (an example of a metal electrical connection means provided on the side close to the wall surface of the intake duct 1). , And a heat resistor 22 which inhibits heat transfer.
The heat resistor 22 is an insulating member such as ceramic having a thermal conductivity lower than that of the metal forming the lead terminal 17 and the heat dissipating plate 16.

この熱抵抗体２２の表面には、導電性の信号線がプリント技術等により設けられており、複数のリード端子１７と、回路基板１５のプリント配線とは、熱抵抗体２２の表面に設けられた信号線を介して電気的に接続される。
具体的には、各リード端子１７と熱抵抗体２２の信号線がワイヤボンディング１９を介して電気的に接続されるとともに、熱抵抗体２２の信号線と回路基板１５のプリント配線がワイヤボンディング１９を介して電気的に接続される。 A conductive signal line is provided on the surface of the thermal resistor 22 by printing technology or the like, and the plurality of lead terminals 17 and the printed wiring of the circuit board 15 are provided on the surface of the thermal resistor 22. It is electrically connected through the signal line.
Specifically, each lead terminal 17 and the signal line of the thermal resistor 22 are electrically connected through the wire bonding 19, and the signal line of the thermal resistor 22 and the printed wiring of the circuit board 15 are wire-bonded 19. Are electrically connected via

このように設けることで、エンジンルーム内の熱を蓋部２が受熱した状態であっても、蓋部２に支持されるリード端子１７から放熱プレート１６に熱が伝わる不具合を熱抵抗体２２によって抑えることができる。これにより、湿度検出素子１３の温度をより確実に吸気の温度に近づけることができるため、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 By providing in this manner, even if the lid 2 receives heat in the engine room, the heat resistor 22 can not transmit heat from the lead terminals 17 supported by the lid 2 to the heat dissipation plate 16. It can be suppressed. As a result, the temperature of the humidity detection element 13 can be more reliably brought close to the temperature of the intake air, so that the detection accuracy of the humidity by the humidity sensor 12 can be more reliably improved.

［実施例７］
実施例７を図７に基づき説明する。
この実施例７は、モールド樹脂１８における窓部１８ａの周囲の一部または全部に、伝熱性に優れた金属板２１（例えば、アルミニウムや銅など）を配置したものである。
なお、金属板２１は、窓部１８ａの周囲を全周に亘って囲む環状板であっても良いし、１つまたは複数の独立した板材であっても良い。
また、金属板２１とモールド樹脂１８との結合手段は限定するものではなく、例えば金属板２１の一部がモールド樹脂１８にモールドされるものであっても良いし、接着剤等によりモールド樹脂１８の表面に金属板２１が固定されるものであっても良い。 [Example 7]
A seventh embodiment will be described based on FIG.
In the seventh embodiment, a metal plate 21 (e.g., aluminum, copper, etc.) excellent in heat conductivity is disposed on a part or all of the periphery of the window 18a in the mold resin 18.
The metal plate 21 may be an annular plate surrounding the entire periphery of the window 18a, or may be one or more independent plate members.
Further, the bonding means of the metal plate 21 and the mold resin 18 is not limited, and for example, a part of the metal plate 21 may be molded on the mold resin 18, or the mold resin 18 may be formed by an adhesive or the like. The metal plate 21 may be fixed to the surface of the.

このように設けることで、湿度検出素子１３の表裏に配置した放熱プレート１６と金属板２１の両方によって、湿度検出素子１３の温度を吸気温度に近づけることができるため、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 By providing in this manner, the temperature of the humidity detection element 13 can be brought close to the intake air temperature by both the heat release plate 16 and the metal plate 21 disposed on the front and back of the humidity detection element 13. Accuracy can be more reliably improved.

［実施例８］
実施例８を図８に基づき説明する。
この実施例８の放熱プレート１６には、湿度検出素子１３と熱結合する箇所に、幅（吸気の流れ方向に沿う幅：ｚ’軸方向の寸法）を広げた幅広部１６ａが設けられる。
この幅広部１６ａにより、湿度検出素子１３と熱結合する箇所における放熱プレート１６の放熱性能を高めることができるため、湿度検出素子１３の温度をより確実に吸気の温度に近づけることができる。これにより、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 [Example 8]
An eighth embodiment will be described based on FIG.
The heat dissipating plate 16 according to the eighth embodiment is provided with a wide portion 16a having a wide width (a width along the flow direction of intake air: a dimension in the z 'axial direction) at a position thermally coupled to the humidity detecting element 13.
The wide portion 16 a can enhance the heat radiation performance of the heat radiation plate 16 at a position thermally coupled to the humidity detection element 13, so that the temperature of the humidity detection element 13 can be brought closer to the temperature of intake air more reliably. Thereby, the detection accuracy of the humidity by the humidity sensor 12 can be more reliably improved.

［実施例９］
実施例９を図９に基づき説明する。
この実施例９の放熱プレート１６には、吸気に直接触れる部位に、吸気との接触面積を拡大する放熱フィン１６ｂが設けられる。
具体的にこの実施例９は、放熱プレート１６の裏面（回路基板１５の搭載面とは反対の面）に複数のリブ状の突起を設けて、放熱プレート１６の放熱性能を高めたものである。 [Example 9]
A ninth embodiment will be described based on FIG.
In the heat dissipating plate 16 of the ninth embodiment, a heat dissipating fin 16b is provided at a portion directly in contact with the intake air, for expanding the contact area with the intake air.
Specifically, in the ninth embodiment, a plurality of rib-like protrusions are provided on the back surface of the heat dissipation plate 16 (surface opposite to the mounting surface of the circuit board 15) to enhance the heat dissipation performance of the heat dissipation plate 16 .

なお、図９（ａ）は、吸気の流れ方向（ｚ軸方向）へ複数の放熱フィン１６ｂが沿うように、複数の放熱フィン１６ｂをｚ’軸方向へ平行に設けたものである。
また、図９（ｂ）は、吸気の流れ方向に対して垂直方向（ｘ軸方向）へ複数の放熱フィン１６ｂが沿うように、複数の放熱フィン１６ｂをｘｚ’軸方向へ平行に設けたものである。 In FIG. 9A, a plurality of radiation fins 16b are provided in parallel in the z'-axis direction such that the plurality of radiation fins 16b extend in the flow direction of the intake air (z-axis direction).
Further, in FIG. 9B, a plurality of radiation fins 16b are provided in parallel in the xz 'axis direction so that the plurality of radiation fins 16b extend in the direction (x axis direction) perpendicular to the flow direction of intake air. It is.

このように、放熱フィン１６ｂによって放熱プレート１６の放熱性能を高めたことで、湿度検出素子１３の温度をより確実に吸気の温度に近づけることができる。このため、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 As described above, the heat radiation performance of the heat radiation plate 16 is enhanced by the heat radiation fins 16 b, whereby the temperature of the humidity detection element 13 can be more reliably brought close to the temperature of the intake air. Therefore, the detection accuracy of the humidity by the humidity sensor 12 can be more reliably enhanced.

［実施例１０］
実施例１０を図１０に基づき説明する。
この実施例１０の回路基板１５には、湿度検出素子１３が搭載される箇所に、表裏を貫通する多数のビアホール１５ａが設けられる。そして、多数のビアホール１５ａの内部には、伝熱性に優れた金属２０（例えばアルミニウムや銅など）が詰められる。
これにより、湿度検出素子１３と放熱プレート１６の間の熱抵抗を小さくできる。即ち、湿度検出素子１３と放熱プレート１６の熱的な結合を高めることができる。このため、湿度検出素子１３の温度をより確実に吸気の温度に近づけることができ、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 [Example 10]
A tenth embodiment will be described based on FIG.
In the circuit board 15 of the tenth embodiment, a large number of via holes 15a passing through the front and back are provided at the location where the humidity detection element 13 is mounted. Then, the metal 20 (for example, aluminum, copper, etc.) excellent in heat conductivity is filled in the inside of the large number of via holes 15a.
Thereby, the thermal resistance between the humidity detection element 13 and the heat radiation plate 16 can be reduced. That is, the thermal coupling between the humidity detection element 13 and the heat dissipation plate 16 can be enhanced. Therefore, the temperature of the humidity detection element 13 can be more reliably brought close to the temperature of the intake air, and the detection accuracy of the humidity by the humidity sensor 12 can be more reliably improved.

［実施例１１］
実施例１１を図１１に基づき説明する。
この実施例１１は、吸気ダクト１における吸気の流れ方向（ｚ軸方向）に対して、湿度センサ１２のｚ’軸方向を傾斜させたものである。
即ち、この実施例１１は、吸気ダクト１の内部を通過する吸気の流れ方向に対して、放熱プレート１６を傾斜配置したものである。 [Example 11]
An eleventh embodiment will be described based on FIG.
In the eleventh embodiment, the z′-axis direction of the humidity sensor 12 is inclined with respect to the flow direction (z-axis direction) of the intake air in the intake duct 1.
That is, in the eleventh embodiment, the heat dissipating plate 16 is disposed obliquely with respect to the flow direction of the intake air passing through the inside of the intake duct 1.

なお、図１１（ａ）は、湿度センサ１２の表面（バイパスハウジング３に対向する面）の下流端がバイパスハウジング３に近づく側に傾斜配置されるものである。
また、図１１（ｂ）は、湿度センサ１２の表面（バイパスハウジング３に対向する面）の上流端がバイパスハウジング３に近づく側に傾斜配置されるものである。 In FIG. 11A, the downstream end of the surface of the humidity sensor 12 (the surface facing the bypass housing 3) is disposed to be inclined toward the side closer to the bypass housing 3.
Further, in FIG. 11B, the upstream end of the surface of the humidity sensor 12 (the surface facing the bypass housing 3) is disposed to be inclined toward the side closer to the bypass housing 3.

このように、吸気の流れ方向に対して放熱プレート１６を傾斜配置することにより、吸気が放熱プレート１６に強く当たるようになり、放熱プレート１６の放熱性をアップすることができる。これにより、湿度検出素子１３の温度をより確実に吸気の温度に近づけることができるため、湿度センサ１２による湿度の検出精度をより確実に高めることができる。 As described above, by disposing the heat dissipating plate 16 at an angle with respect to the flow direction of the intake air, the intake air comes into strong contact with the heat dissipating plate 16 and the heat dissipating property of the heat dissipating plate 16 can be improved. As a result, the temperature of the humidity detection element 13 can be more reliably brought close to the temperature of the intake air, so that the detection accuracy of the humidity by the humidity sensor 12 can be more reliably improved.

上記の実施例では、放熱手段を板状に設ける例（放熱プレート１６）を示したが、放熱手段の形状や厚み等は限定するものではなく、種々の形状を採用することができる。
具体的な一例として、放熱手段をＬ字形、Ｊ字形、Ｕ字形、コ字形などの形状に設けて、モールド樹脂１８から放熱手段の一部を突出させて吸気に触れる放熱手段の面積を増大させ、放熱手段の放熱性能を高めても良い。 In the above embodiment, an example in which the heat dissipating means is provided in a plate shape (the heat dissipating plate 16) is shown, but the shape, thickness and the like of the heat dissipating means are not limited, and various shapes can be adopted.
As a specific example, the heat dissipating means is provided in the shape of L-shape, J-shape, U-shape, U-shape, etc., a part of the heat dissipating means is made to project from the mold resin 18 to increase the area of the heat dissipating means The heat dissipating performance of the heat dissipating means may be enhanced.

上記の実施例では、バイパスハウジング３の外部（請求項１の近傍の一例）に湿度検出素子１３を配置する例を示したが、湿度検出素子１３をバイパスハウジング３の内部（請求項１の近傍の他の例）に配置し、湿度検出素子１３がバイパスハウジング３の内部を通過する吸気の湿度を検出するように設けても良い。
この場合、放熱手段の一部をバイパスハウジング３の外側に突出させるなどして放熱手段の放熱性能を高めることが望ましい。さらに、「放熱手段においてバイパスハウジング３の外部の吸気に直接触れる範囲」と「放熱手段において湿度検出素子１３と熱結合する箇所」の間の熱抵抗を小さく設けることで（例えば、湿度検出素子１３と熱結合する箇所の放熱手段の肉厚を厚く設けることで）、湿度検出素子１３の温度をバイパスハウジング３の外部の吸気の温度に近づけることができる。 In the above embodiment, the humidity detection element 13 is disposed outside the bypass housing 3 (an example in the vicinity of claim 1). However, the humidity detection element 13 is disposed in the bypass housing 3 (near the claim 1) And the humidity detection element 13 may be provided so as to detect the humidity of the intake air passing through the inside of the bypass housing 3.
In this case, it is desirable to enhance the heat dissipation performance of the heat dissipation means by, for example, projecting a part of the heat dissipation means to the outside of the bypass housing 3. Furthermore, the thermal resistance between “the range where the heat dissipation means directly touches the intake air outside the bypass housing 3” and “the point where the heat dissipation means thermally couples with the humidity detection element 13” is provided small (for example, the humidity detection element 13 The temperature of the humidity detection element 13 can be made close to the temperature of the intake air outside the bypass housing 3 by providing a thick wall of the heat dissipating means in a portion thermally coupled to

上記の実施例では、湿度検出素子１３と放熱手段（上記の実施例では放熱プレート１６）が回路基板１５を介して熱結合する例を示したが、限定するものではなく、薄いマイカ板などを介して湿度検出素子１３と放熱手段を熱結合しても良く、あるいは湿度検出素子１３と放熱手段が直接触れるものであっても良い。また、熱結合の結合度合を高める目的でシリコングリス等を用いても良い。 Although the above embodiment shows an example in which the humidity detecting element 13 and the heat radiating means (the heat radiating plate 16 in the above embodiment) are thermally coupled via the circuit board 15, the invention is not limited thereto. The humidity detection element 13 and the heat dissipation means may be thermally coupled, or the humidity detection element 13 and the heat dissipation means may be in direct contact with each other. In addition, silicon grease or the like may be used to increase the degree of thermal bonding.

１吸気ダクト
３バイパスハウジング
４流量センサ
５バイパス通路
６サブバイパス通路
１３湿度検出素子
１６放熱プレート（放熱手段） DESCRIPTION OF SYMBOLS 1 intake duct 3 bypass housing 4 flow sensor 5 bypass passage 6 sub bypass passage 13 humidity detection element 16 heat radiation plate (heat radiation means)

Claims

Is arranged inside the air intake duct for guiding the air to the engine (1), wherein to form therein a passage (5,6) where a part of the intake air flowing through the inside passes the intake duct (1) Ruha Ujingu (3) When,
A flow rate sensor for pre-measuring the flow rate of intake air passing through the interior of the diesel train Ujingu (3) (4),
Humidity sensing element before the measurement of the humidity of the intake air passing through the vicinity of the diesel train Ujingu (3) and (13),
Before SL comprising a humidity sensing element (13) thermally coupled to heat dissipating means and (16),
The air flow measuring device is characterized in that the heat dissipating means (16) has a heat dissipating property higher than that of the resin, and is located at a position projecting into the air intake duct (1) from the inner wall of the air intake duct (1) .

In the air flow measuring device according to claim 1,
A connector (7) for outputting measured values to an external device;
And electrical connection means (17) disposed closer to the connector (7) than the heat dissipation means (16);
An air flow measuring device characterized in that the electrical connection means (17) is disposed apart from the heat dissipation means (16) .

In the air flow measuring device according to claim 2,
The air flow measuring device according to claim 1, wherein the electrical connection means (17) is separated from the heat release means (16) with a mold resin (18) interposed therebetween .

In the air flow measuring device according to claim 2 or 3 ,
A cover (2) fixed to the intake duct (1);
The housing (3) is integrally provided with the lid (2) and protrudes into the intake duct (1).
The air flow measuring device, wherein the connector (7) is provided on the lid (2) and exists outside the air intake duct (1) .

The air flow measuring device according to any one of claims 2 to 4 .
The electrical connection means (17) is a lead terminal (17) electrically connected to the circuit board (15) on which the humidity detection element (13) is mounted, and a part is exposed in the connector (7) air flow rate measuring apparatus characterized by being.

In the air flow measuring device according to claim 1 ,
The humidity detection element (13) is disposed in the vicinity of the housing (3)
The air flow measuring device characterized in that the heat dissipating means (16) is a heat dissipating plate (16) serving also as a support plate for supporting a circuit board (15) on which the humidity detecting element (13) is mounted .

In the air flow measuring device according to claim 6 ,
An air flow measuring device comprising a mold resin (18) for molding at least a part of the humidity detection element (13) and the heat dissipation plate (16) .

In the air flow measuring device according to claim 7 ,
An air flow measuring device characterized in that the heat radiation plate (16) is provided with a projecting portion (16d) which protrudes to the outside of the mold resin (18) to enlarge a contact area with intake air.

The air flow measuring device according to any one of claims 6 to 8 .
The heat dissipating plate (16) is
It comprises a notch or an opening that impedes heat transfer between the side closer to the wall surface of the intake duct (1) than the humidity detection element (13) and the point thermally coupled to the humidity detection element (13) An air flow measuring device comprising a lightening portion (16c) .

In the air flow measurement device according to claim 7 or 8 ,
The mold resin (18) is provided with a window (18a) that directly leads intake air to a part of the humidity detection element (13).
A metal plate (21) is disposed on a part or all of the periphery of the window (18a) in the mold resin (18) .

The air flow measuring device according to any one of claims 6 to 10 .
The air flow measuring device characterized in that the heat radiation plate (16) includes a wide portion (16a) which widens the width in the flow direction of the intake air at a location thermally coupled to the humidity detection element (13) .

The air flow measuring device according to any one of claims 6 to 11 .
The air flow measuring device characterized in that the heat dissipating plate (16) is provided with a heat dissipating fin (16b) for enlarging a contact area with the intake air at a portion directly in contact with the intake air.

The air flow measuring device according to any one of claims 6 to 12.
An air flow measuring device characterized in that the heat dissipation plate (16) is disposed to be inclined with respect to the flow direction of the intake air passing through the inside of the intake duct (1).

The air flow measuring device according to any one of claims 1 to 13.
A mold resin (18) for molding the humidity detection element (13);
In the mold resin (18), at least one of the thickness dimension or the width dimension of the mold resin (18) on the side closer to the wall surface of the intake duct (1) than the humidity detection element (13) An air flow measuring device characterized in that a reduction portion (α) is provided to reduce in size compared to a portion.

The air flow measuring device according to any one of claims 1 to 14.
A connector (7) for outputting measured values to an external device;
Electrical connection means (17) disposed closer to the connector (7) than the heat dissipation means (16);
And a circuit board (15) on which the humidity detection element (13) is mounted;
The electrical connection means (17) is provided on the side close to the wall surface of the intake duct (1),
The air flow rate measurement is characterized in that the circuit board (15) and the electrical connection means (17) are electrically connected via a signal line provided on a thermal resistor (22) that inhibits heat transfer. apparatus.

The air flow measuring device according to any one of claims 1 to 15.
A circuit board (15) on which the humidity detection element (13) is mounted;
In the circuit board (15), a large number of via holes (15a) penetrating the circuit board (15) are provided at locations where the humidity detection element (13) is mounted.
An air flow measuring device characterized in that a metal (20) is filled in the inside of the large number of via holes (15a).

The air flow measuring device according to any one of claims 1 to 5.
The air flow measuring device is characterized in that the humidity detection element (13) is disposed inside the housing (3) and detects the humidity of air passing through the inside of the housing (3).

The air flow measuring device according to any one of claims 1 to 5.
The air flow measuring device, wherein the heat radiating means (16) is in direct contact with the humidity detecting element.

The air flow measuring device according to any one of claims 1 to 18.
The air flow measuring device is characterized in that the housing (3) is a bypass housing having air passages (5, 6) through which a part of air flowing inside the intake duct (1) passes.