JPWO2020075311A1

JPWO2020075311A1 - Flapper type flow detector

Info

Publication number: JPWO2020075311A1
Application number: JP2019502108A
Authority: JP
Inventors: 創重田; 中山　諭; 諭中山; 利彦篠原
Original assignee: SHOWA INSTRUMENT INFORMATION CORPORATION
Current assignee: SHOWA INSTRUMENT INFORMATION CORPORATION
Priority date: 2018-10-12
Filing date: 2018-11-07
Publication date: 2021-02-15
Anticipated expiration: 2038-11-07
Also published as: JP6513323B1

Abstract

構造が簡単で組立て作業等が容易であり小型化しやすいフラッパ式流量検出器を提供する。フラッパ式流量検出器１０は、測定対象の流体の流量に応じて回転角が変化するように設置されたフラッパ１２と、フラッパの回転中心１４側の基端部１２Ａを径方向内側から摺動可能に支持する中心軸部１６と、フラッパと一体で回転するようにフラッパ１２の回転中心に同軸的な位置に設置されたマグネット１８と、マグネット１８の回転角を検出するためのセンサ２０と、を備え、中心軸部１６、マグネット１８及びセンサ２０は、この順で軸方向に並んで、且つ、軸方向に相互に離間して設置されている。Provided is a flapper type flow rate detector having a simple structure, easy assembly work, and easy miniaturization. The flapper type flow rate detector 10 can slide the flapper 12 installed so that the rotation angle changes according to the flow rate of the fluid to be measured and the base end portion 12A on the rotation center 14 side of the flapper from the inside in the radial direction. A central shaft portion 16 supported by the above, a magnet 18 installed at a position coaxial with the rotation center of the flapper 12 so as to rotate integrally with the flapper, and a sensor 20 for detecting the rotation angle of the magnet 18 are provided. The central shaft portion 16, the magnet 18, and the sensor 20 are arranged in this order in the axial direction and separated from each other in the axial direction.

Description

本発明は、フラッパの回転角に基づいて流体の流量を検出するフラッパ式流量検出器に関する。 The present invention relates to a flapper type flow rate detector that detects a fluid flow rate based on the angle of rotation of the flapper.

従来、空気や水等の流体の流量を検出するための検出器としてフラッパ式流量検出器が知られている。フラッパ式流量検出器は、測定対象の流体の流路を閉塞可能、且つ、流体の流動によって基端を中心に回転可能であるように設置されたフラッパと、フラッパを閉位置の側に付勢するばね等の付勢手段とを備えている。流体の流量に応じてフラッパがばね等の付勢力に抗して閉位置から所定の角度回転するので、フラッパの回転角に基づいて流体の流量を測定することができる。フラッパの回転角を検出する手法としては、フラッパの回転軸に直接指針を取付けて指針の回転を読み取る手法や、フラッパと指針にそれぞれマグネットを取付け、磁力によりフラッパに連動して回転する指針の回転を読み取る手法が知られている。また、フラッパにマグネットを取付け、マグネットの位置をポテンショメータ等で電気的に検出する手法も知られている。また、透視窓を介してフラッパを直接視認してフラッパの回転角を読み取る手法も知られている（例えば、特許文献１〜４参照）。 Conventionally, a flapper type flow rate detector is known as a detector for detecting the flow rate of a fluid such as air or water. The flapper type flow rate detector has a flapper installed so that the flow path of the fluid to be measured can be blocked and can rotate around the base end by the flow of the fluid, and the flapper is urged to the closed position side. It is equipped with an urging means such as a spring. Since the flapper rotates from the closed position by a predetermined angle against the urging force of the spring or the like according to the flow rate of the fluid, the flow rate of the fluid can be measured based on the rotation angle of the flapper. As a method of detecting the rotation angle of the flapper, a method of directly attaching a pointer to the rotation axis of the flapper to read the rotation of the pointer, or a method of attaching magnets to the flapper and the pointer respectively and rotating the pointer in conjunction with the flapper by magnetic force. The method of reading is known. Further, a method of attaching a magnet to a flapper and electrically detecting the position of the magnet with a potentiometer or the like is also known. Further, there is also known a method of directly visually recognizing the flapper through a perspective window to read the rotation angle of the flapper (see, for example, Patent Documents 1 to 4).

特許文献１には、フラッパ、回転軸、軸受板、後面板、上面板、底面板及び流路ガイドなどからなるフラッパ機構部が前面パネルとともに一体で筐体に着脱できるように構成されたフラッパ式流量計が開示されている。回転軸はフラッパと一体で回転するようにフラッパに取付けられ、回転軸を支持する軸受は前面側の軸受板と後面板に設置されている。また、回転軸には指針あるいは磁石が結合される。 Patent Document 1 describes a flapper type in which a flapper mechanism including a flapper, a rotating shaft, a bearing plate, a rear surface plate, a top plate, a bottom plate, a flow path guide, and the like is integrally attached to and detached from a housing together with a front panel. A flow meter is disclosed. The rotating shaft is attached to the flapper so as to rotate integrally with the flapper, and the bearings supporting the rotating shaft are installed on the front bearing plate and the rear plate. Further, a pointer or a magnet is coupled to the rotating shaft.

特許文献２には、フラッパとフラッパを回動自在に支持する支持部が、ボディ部の外周面の箱状の突出部に装着されたフラッパ式フロースイッチが開示されている。支持部はボディ部の外周面の突出部に組付けられた後、突出部の開口部と蓋体により挟持されて突出部に固定される。フラッパの基端の軸方向の両側には一対の取付片が設けられており、これら一対の取付片が支持部を挟むように支持部にフラッパが組付けられている。フラッパを軸着するシャフトは、一対の取付片及び支持部に挿通されている。なお、特許文献２のフラッパ式フロースイッチは、フラッパの材料として樹脂を採用したり、マグネットをフラッパの回転軸に同軸的な位置に設置することによりフラッパやマグネットの重力の影響が抑制されている。３つの磁石が一対の取付片及び支持部に設置されており、これらの磁石にも貫通孔が形成され、この貫通孔にシャフトが挿通されている。 Patent Document 2 discloses a flapper type flow switch in which a flapper and a support portion for rotatably supporting the flapper are mounted on a box-shaped protrusion on an outer peripheral surface of the body portion. The support portion is assembled to the protruding portion on the outer peripheral surface of the body portion, and then is sandwiched between the opening of the protruding portion and the lid and fixed to the protruding portion. A pair of mounting pieces are provided on both sides of the base end of the flapper in the axial direction, and the flapper is assembled to the support portion so that the pair of mounting pieces sandwich the support portion. The shaft around which the flapper is attached is inserted through a pair of mounting pieces and a support portion. The flapper type flow switch of Patent Document 2 uses resin as the material of the flapper, and the influence of gravity of the flapper and the magnet is suppressed by installing the magnet at a position coaxial with the rotation axis of the flapper. .. Three magnets are installed in a pair of mounting pieces and a support portion, and through holes are also formed in these magnets, and a shaft is inserted through the through holes.

特許文献３には、測定体（フラッパ）と緩衝体がウェブで結合され、緩衝体の基端のボスが支承軸に不動に固定され、支承軸が測定体と一体で回転するように構成された流量測定装置が開示されている。緩衝体は、ケーシングの側方に突出して形成された緩衝室に収容されている。特許文献３には、測定体または支承軸の角度位置を検出する手段の例としてポテンショメータが記載されている。また、特許文献３には、支承軸の軸受として玉軸受を用いることで摩擦抵抗を低減することが記載されている。 Patent Document 3 is configured such that the measuring body (flapper) and the buffer are connected by a web, the boss at the base end of the buffer is immovably fixed to the bearing shaft, and the bearing shaft rotates integrally with the measuring body. The flow measuring device is disclosed. The shock absorber is housed in a shock absorber formed so as to project laterally to the casing. Patent Document 3 describes a potentiometer as an example of a means for detecting an angular position of a measuring body or a bearing shaft. Further, Patent Document 3 describes that frictional resistance is reduced by using ball bearings as bearings for bearing shafts.

特許文献４には、フラッパーの基端の軸方向の両側にヒンジ部が設けられ、ケーシングの内側に突出する一対の突堤に支軸受け部が設けられ、これらヒンジ部及び支軸受け部に支軸が挿通されたフラッパー式検流器が開示されている。 In Patent Document 4, hinge portions are provided on both sides in the axial direction of the base end of the flapper, support bearing portions are provided on a pair of jetties protruding inside the casing, and the support shafts are provided on these hinge portions and the support bearing portions. The inserted flapper type flow detector is disclosed.

このようなフラッパ式流量検出器は様々な設備や機械の配管に設置されて使用されるが、設備や機械によってはフラッパ式流量検出器を設置するための充分なスペースがない場合がある。また、フラッパ式流量検出器を設置するだけのスペースはあっても、フラッパ式流量検出器の設置作業やメンテナンス作業のための充分なスペースがない場合もある。このため、コンパクトなフラッパ式流量検出器に対するニーズがある。また、メンテナンス作業等の容易化のため、フラッパや軸受等の内部機構の組立てや分解が容易なフラッパ式流量検出器に対するニーズがある。特許文献１のフラッパ式流量計は、フラッパ及びその軸受機構を前面パネルとともに一体で筐体に着脱できるので、メンテナンス作業は容易である。また、特許文献２のフラッパ式フロースイッチも、フラッパ及びその軸受機構を一体でボディ部の突出部に着脱できるので、メンテナンス作業は容易である。 Such a flapper type flow rate detector is installed and used in the piping of various equipments and machines, but depending on the equipment and machine, there may not be sufficient space for installing the flapper type flow rate detector. Further, even if there is enough space for installing the flapper type flow rate detector, there may be insufficient space for the installation work and maintenance work of the flapper type flow rate detector. Therefore, there is a need for a compact flapper type flow rate detector. Further, in order to facilitate maintenance work and the like, there is a need for a flapper type flow rate detector that facilitates assembly and disassembly of internal mechanisms such as flappers and bearings. In the flapper type flowmeter of Patent Document 1, the flapper and its bearing mechanism can be integrally attached to and detached from the housing together with the front panel, so that maintenance work is easy. Further, in the flapper type flow switch of Patent Document 2, the flapper and its bearing mechanism can be integrally attached to and detached from the protruding portion of the body portion, so that the maintenance work is easy.

特許第５１８４４４０号公報Japanese Patent No. 5184440 特許第３５８１８９６号公報Japanese Patent No. 3581896 特開平０２−０１３２４８号公報Japanese Unexamined Patent Publication No. 02-013248 特許第３１９７８５２号公報Japanese Patent No. 3197852

しかしながら、特許文献１のフラッパ式流量計や特許文献２のフラッパ式フロースイッチは、フラッパ及びその軸受機構等で構成されるサブアッセンブリをケーシングに着脱する構成であるため、部品点数が多く構造が複雑であるという問題がある。具体的には、特許文献１のフラッパ式流量計は、筐体とは別に筐体の中に後面板、上面板、底面板で構成される枠体を備える構成であるため、部品点数が多く構造が複雑である。また、特許文献２のフラッパ式フロースイッチも、３つのマグネットを備えるため部品点数が多く、また、３つのマグネットに貫通孔が形成されてシャフトが挿通されるため構造が複雑である。 However, since the flapper type flow meter of Patent Document 1 and the flapper type flow switch of Patent Document 2 have a configuration in which a subassembly composed of a flapper and its bearing mechanism and the like is attached to and detached from the casing, the number of parts is large and the structure is complicated. There is a problem that it is. Specifically, the flapper type flowmeter of Patent Document 1 has a configuration in which a frame body composed of a rear face plate, a top plate, and a bottom plate is provided in the housing separately from the housing, so that the number of parts is large. The structure is complicated. Further, the flapper type flow switch of Patent Document 2 also has a large number of parts because it is provided with three magnets, and the structure is complicated because through holes are formed in the three magnets and the shaft is inserted.

さらに、特許文献２のフラッパ式フロースイッチは、フラッパ及びその軸受機構を一体で着脱するために、ボディ部の外周面に箱状の突出部が設けられた構成であるため小型化しにくいという問題がある。また、特許文献３の流量測定装置も、緩衝体を収容する緩衝室が、ケーシングの側方に突出して形成される構成であるため小型化しにくいという問題がある。また、特許文献４のフラッパー式検流器は、フラッパーをケーシングに組み付ける際に、フラッパーのヒンジ部とケーシングの内側の一対の支軸受け部との干渉を避けるため、まず本来の回転中心から径方向にヒンジ部をずらしてフラッパーをケーシング内に挿入してから、ヒンジ部の位置が本来の回転中心に一致するようにフラッパーを径方向に移動させる必要がある。このためケーシング内にフラッパーの径方向の移動のためのスペースを確保する必要があり、やはり小型化しにくいという問題がある。 Further, the flapper type flow switch of Patent Document 2 has a problem that it is difficult to miniaturize because a box-shaped protrusion is provided on the outer peripheral surface of the body portion in order to integrally attach and detach the flapper and its bearing mechanism. is there. Further, the flow rate measuring device of Patent Document 3 also has a problem that it is difficult to miniaturize because the buffer chamber accommodating the buffer is formed so as to project to the side of the casing. Further, in the flapper type flow detector of Patent Document 4, when assembling the flapper to the casing, in order to avoid interference between the hinge portion of the flapper and the pair of support bearing portions inside the casing, first, in the radial direction from the original center of rotation. After inserting the flapper into the casing by shifting the hinge portion, it is necessary to move the flapper in the radial direction so that the position of the hinge portion coincides with the original rotation center. Therefore, it is necessary to secure a space in the casing for moving the flapper in the radial direction, and there is also a problem that it is difficult to miniaturize the flapper.

本発明は以上の問題点に鑑みてなされたものであって、構造が簡単で組立て作業等が容易であり小型化しやすいフラッパ式流量検出器を提供することをその課題とする。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a flapper type flow rate detector having a simple structure, easy assembly work, and easy miniaturization.

本発明は、測定対象の流体の流量に応じて回転角が変化するように設置されたフラッパと、フラッパの回転中心側の基端部を径方向内側から摺動可能に支持する中心軸部と、フラッパと一体で回転するようにフラッパの回転中心に同軸的な位置に設置されたマグネットと、マグネットの回転角を検出するためのセンサと、を備え、中心軸部、マグネット及びセンサは、この順で軸方向に並んで、且つ、軸方向に相互に離間して設置されたフラッパ式流量検出器により上記課題を解決したものである。 The present invention includes a flapper installed so that the rotation angle changes according to the flow rate of the fluid to be measured, and a central shaft portion that slidably supports the base end portion of the flapper on the rotation center side from the inside in the radial direction. A magnet installed at a position coaxial with the center of rotation of the flapper so as to rotate integrally with the flapper, and a sensor for detecting the rotation angle of the magnet are provided, and the central shaft portion, the magnet, and the sensor are provided with this. The above problem is solved by a flapper type flow rate detector installed in order in the axial direction and separated from each other in the axial direction.

このフラッパ式流量検出器は、中心軸部、マグネット及びセンサが、この順で軸方向に並んで設置されるので、回転中心の径方向に小型化しやすい。また、中心軸部、マグネット及びセンサは、軸方向に相互に離間して設置されるので、マグネットやセンサに孔を形成して中心軸部を挿通する必要がない。したがって、構造が簡単で組立て作業が容易である。 In this flapper type flow rate detector, since the central shaft portion, the magnet, and the sensor are installed side by side in the axial direction in this order, it is easy to miniaturize in the radial direction of the center of rotation. Further, since the central shaft portion, the magnet, and the sensor are installed so as to be separated from each other in the axial direction, it is not necessary to form a hole in the magnet or the sensor to insert the central shaft portion. Therefore, the structure is simple and the assembly work is easy.

また、上記のフラッパ式流量検出器において、フラッパの基端部における軸方向の一方側の第１端部及び他方側の第２端部のうち、第２端部の外周面に接触または近接して第２端部を径方向外側から回転可能に保持する第２端部外側保持部をさらに備え、中心軸部は、第１端部及び第２端部のうち少なくとも第１端部を径方向内側から摺動可能に支持し、且つ、第１端部の近傍において片持ち状態で実質的にケーシングに支持され、マグネットは、前記第２端部に設置された構成とするとよい。 Further, in the above-mentioned flapper type flow rate detector, of the first end on one side in the axial direction and the second end on the other side of the base end of the flapper, the contact or proximity to the outer peripheral surface of the second end. A second end outer holding portion that rotatably holds the second end portion from the radial outer side is further provided, and the central shaft portion has at least the first end portion of the first end portion and the second end portion in the radial direction. It is preferable that the magnet is slidably supported from the inside and is substantially supported by the casing in a cantilevered state in the vicinity of the first end portion, and the magnet is installed at the second end portion.

このようにフラッパの基端部を径方向内側から摺動可能に支持する中心軸部が片持ち状態で実質的にケーシングに支持される構成とすることで、フラッパをケーシングに組み付ける際、フラッパ、中心軸部を軸方向のみに移動させればよく、フラッパを径方向に移動させる必要がないので、さらに径方向に小型化しやすく、また組立て作業が容易である。また、第２端部を径方向外側から回転可能に保持する第２端部外側保持部をさらに備えるので、中心軸部が第１端部の近傍において片持ち状態で支持される構成であっても、フラッパの径方向の振れを抑制できる。 In this way, the central shaft portion that slidably supports the base end portion of the flapper from the inside in the radial direction is configured to be substantially supported by the casing in a cantilevered state, so that when the flapper is assembled to the casing, the flapper, Since the central shaft portion only needs to be moved in the axial direction and the flapper does not need to be moved in the radial direction, the size of the flapper can be further reduced in the radial direction, and the assembly work is easy. Further, since the outer holding portion of the second end portion that rotatably holds the second end portion from the outer side in the radial direction is further provided, the central shaft portion is supported in the cantilever state in the vicinity of the first end portion. However, the radial runout of the flapper can be suppressed.

さらに、上記のフラッパ式流量検出器において、中心軸部は、第２端部も径方向内側から摺動可能に支持し、中心軸部における第２端部との摺動面及び第２端部における中心軸部との摺動面の一方は、回転中心を含む断面における形状が他方に向かって凸である丸みを帯びた形状である構成としてもよい。 Further, in the above-mentioned flapper type flow rate detector, the central shaft portion also slidably supports the second end portion from the inside in the radial direction, and the sliding surface and the second end portion of the central shaft portion with the second end portion. One of the sliding surfaces of the sliding surface with the central shaft portion may have a rounded shape in which the shape in the cross section including the center of rotation is convex toward the other.

このように中心軸部が第２端部も径方向内側から摺動可能に支持する構成とすることで、フラッパの径方向の振れを抑制する効果を高めることができる。また、中心軸部における第２端部との摺動面及び第２端部における中心軸部との摺動面の一方が、他方に向かって凸である丸みを帯びた形状である構成とすることで、中心軸部と第２端部との摺動部の接触面積が小さくなるので摺動抵抗を低減できる。さらに、フラッパや中心軸部が径方向に振れた場合でも、中心軸部と第２端部との摺動抵抗の増大を防止または抑制できる。 By forming the central shaft portion so as to slidably support the second end portion from the inside in the radial direction in this way, the effect of suppressing the radial runout of the flapper can be enhanced. Further, one of the sliding surface with the second end portion of the central shaft portion and the sliding surface with the central shaft portion at the second end portion has a rounded shape that is convex toward the other. As a result, the contact area between the central shaft portion and the second end portion of the sliding portion becomes smaller, so that the sliding resistance can be reduced. Further, even when the flapper or the central shaft portion swings in the radial direction, it is possible to prevent or suppress an increase in the sliding resistance between the central shaft portion and the second end portion.

また、上記のフラッパ式流量検出器において、中心軸部は、第２端部も径方向内側から摺動可能に支持し、第２端部は、中心軸部の軸方向の先端面と接触または近接する軸方向規制面を備え、中心軸部の先端面及び第２端部の軸方向規制面の一方は、他方に向かって凸である丸みを帯びた形状である構成としてもよい。 Further, in the above-mentioned flapper type flow rate detector, the central shaft portion also slidably supports the second end portion from the inside in the radial direction, and the second end portion contacts or contacts the tip surface of the central shaft portion in the axial direction. One of the tip surface of the central shaft portion and the axial regulation surface of the second end portion may be configured to have a rounded shape that is convex toward the other.

このように第２端部が中心軸部の軸方向の先端面と接触または近接する軸方向規制面を備える構成とすることで、フラッパの第１端部側への移動を中心軸部によって規制することができる。また、中心軸部の先端面及び第２端部の軸方向規制面の一方が、他方に向かって凸である丸みを帯びた形状である構成とすることで、中心軸部の先端面と第２端部の軸方向規制面との接触面積が小さくなるので摺動抵抗を低減できる。さらに、フラッパや中心軸部が径方向に振れた場合でも、中心軸部の先端面と第２端部の軸方向規制面との摺動抵抗の増大を防止または抑制できる。 By providing the second end portion with an axial regulation surface that is in contact with or close to the axial tip surface of the central shaft portion, the movement of the flapper toward the first end portion is restricted by the central shaft portion. can do. Further, one of the tip surface of the central shaft portion and the axial regulation surface of the second end portion has a rounded shape that is convex toward the other, so that the tip surface of the central shaft portion and the second end surface are formed. Since the contact area of the two ends with the axial regulation surface becomes small, the sliding resistance can be reduced. Further, even when the flapper or the central shaft portion swings in the radial direction, it is possible to prevent or suppress an increase in sliding resistance between the tip surface of the central shaft portion and the axial regulation surface of the second end portion.

また、フラッパは基端部の軸方向の両側の端面において他の部材と接触または近接して軸方向の移動が規制され、基端部の軸方向の少なくとも一方側の端面は回転中心に同軸的な環状であり、且つ、回転中心を含む断面における形状が接触または近接する他の部材に向かって凸である丸みを帯びた形状である構成としてもよい。 In addition, the flapper is restricted from moving in the axial direction in contact with or close to other members at the end faces on both sides in the axial direction of the base end, and the end face on at least one side in the axial direction of the base end is coaxial with the center of rotation. The shape may be an annular shape and the shape in the cross section including the center of rotation may be a rounded shape that is convex toward other members that are in contact with or close to each other.

このようにフラッパは基端部の軸方向の端面が回転中心に同軸的な環状であり、且つ、回転中心を含む断面における形状が、接触または近接する他の部材に向かって凸である丸みを帯びた形状である構成とすることで、フラッパの基端部と他の部材との接触面積が小さくなるので摺動抵抗を低減できる。さらに、フラッパが径方向に振れた場合でも、フラッパの端面と他の部材との摺動抵抗の増大を防止または抑制できる。 In this way, the flapper has a roundness in which the axial end surface of the base end portion is an annular shape coaxial with the center of rotation, and the shape in the cross section including the center of rotation is convex toward other members in contact with or close to it. Since the contact area between the base end portion of the flapper and other members is reduced by the configuration having a tinged shape, sliding resistance can be reduced. Further, even when the flapper swings in the radial direction, an increase in sliding resistance between the end face of the flapper and another member can be prevented or suppressed.

本発明によれば、構造が簡単で組立て作業等が容易であり小型化しやすいフラッパ式流量検出器を実現できる。 According to the present invention, it is possible to realize a flapper type flow rate detector having a simple structure, easy assembly work, and easy miniaturization.

本発明の実施形態に係るフラッパ式流量検出器の全体構造を示すフラッパの回転中心に沿う断面図Cross-sectional view along the rotation center of the flapper showing the overall structure of the flapper type flow rate detector according to the embodiment of the present invention. 同フラッパ式流量検出器のフラッパを示す斜視図Perspective view showing the flapper of the flapper type flow rate detector 同フラッパを拡大して示す断面図Enlarged cross-sectional view of the flapper 同フラッパ式流量検出器の中心軸部及びケーシングを示す斜視図Perspective view showing the central shaft portion and the casing of the flapper type flow rate detector. 同中心軸部を拡大して示す断面図Cross-sectional view showing an enlarged view of the central shaft

図１に示されるように、本発明の実施形態に係るフラッパ式流量検出器１０は、測定対象の流体の流量に応じて回転角が変化するように設置されたフラッパ１２と、フラッパ１２の回転中心１４側の基端部１２Ａを径方向内側から摺動可能に支持する中心軸部１６と、フラッパ１２と一体で回転するようにフラッパ１２の回転中心１４に同軸的な位置に設置されたマグネット１８と、マグネット１８の回転角を検出するためのセンサ２０と、を備え、中心軸部１６、マグネット１８及びセンサ２０は、この順で軸方向に並んで、且つ、軸方向に相互に離間して設置されている。 As shown in FIG. 1, the flapper type flow rate detector 10 according to the embodiment of the present invention has a flapper 12 installed so that the rotation angle changes according to the flow rate of the fluid to be measured, and the rotation of the flapper 12. A central shaft portion 16 that slidably supports the base end portion 12A on the center 14 side from the inside in the radial direction, and a magnet installed at a position coaxial with the rotation center 14 of the flapper 12 so as to rotate integrally with the flapper 12. 18 and a sensor 20 for detecting the rotation angle of the magnet 18 are provided, and the central shaft portion 16, the magnet 18 and the sensor 20 are arranged in this order in the axial direction and separated from each other in the axial direction. Is installed.

図２に示されるように、フラッパ１２は基端部１２Ａと板状体部１２Ｂとが一体で形成された構成である。なお、フラッパ１２の材料は例えば合成樹脂である。基端部１２Ａにおける軸方向の一方側の第１端部２２は、中心軸部１６が挿通する貫通孔が形成された円板状体である。図３に拡大して示されるように、第１端部２２におけるマグネット１８から離れる側の側面２２Ａ（基端部１２Ａの軸方向の端面）は、回転中心１４に同軸的な環状であり、且つ、回転中心１４を含む断面における形状が後述する押え板２８（接触または近接する他の部材）に向かって凸である丸みを帯びた形状である。なお、板状体部１２Ｂは一部が第１端部２２よりも押え板２８の側に突出している。言い換えれば、第１端部２２の側面２２Ａは板状体部１２Ｂの端面よりも押え板２８から離れる側に配置されており、このスペースに入り込むように押え板２８が配置されている。 As shown in FIG. 2, the flapper 12 has a configuration in which a base end portion 12A and a plate-shaped body portion 12B are integrally formed. The material of the flapper 12 is, for example, a synthetic resin. The first end portion 22 on one side in the axial direction of the base end portion 12A is a disk-shaped body having a through hole through which the central shaft portion 16 is inserted. As shown enlarged in FIG. 3, the side surface 22A (axial end surface of the base end portion 12A) of the first end portion 22 on the side away from the magnet 18 is an annular shape coaxial with the rotation center 14 and is annular. , The shape in the cross section including the rotation center 14 is a rounded shape that is convex toward the pressing plate 28 (another member in contact with or in close proximity to the pressing plate 28) described later. A part of the plate-shaped body portion 12B protrudes toward the pressing plate 28 from the first end portion 22. In other words, the side surface 22A of the first end portion 22 is arranged on the side away from the pressing plate 28 from the end surface of the plate-shaped body portion 12B, and the pressing plate 28 is arranged so as to enter this space.

一方、基端部１２Ａにおける他方側の第２端部２４は略円筒形状であり、一部が板状体部１２Ｂよりも第１端部２２から離れる側に突出している。第２端部２４の内側は軸方向の中間付近において隔壁２４Ａにより隔てられている。隔壁２４Ａの第１端部２２に近い側には中心軸部１６と遊嵌する凹部２４Ｂが形成されている。また、隔壁２４Ａの第１端部２２から離れる側にはマグネット１８が嵌合する凹部２４Ｃが形成されている。凹部２４Ｂ及び凹部２４Ｃの内周面は円筒面である。なお、第１端部２２及び第２端部２４の外径は等しく、図２に示されるように、これらと同じ外径のハーフパイプ状の中間部２６により連結されるように、第１端部２２、第２端部２４、中間部２６は板状体部１２Ｂと一体で形成されている。 On the other hand, the second end portion 24 on the other side of the base end portion 12A has a substantially cylindrical shape, and a part thereof protrudes from the plate-shaped body portion 12B toward the side away from the first end portion 22. The inside of the second end portion 24 is separated by a partition wall 24A near the middle in the axial direction. A recess 24B that loosely fits with the central shaft portion 16 is formed on the side of the partition wall 24A near the first end portion 22. Further, a recess 24C into which the magnet 18 is fitted is formed on the side of the partition wall 24A away from the first end portion 22. The inner peripheral surfaces of the recess 24B and the recess 24C are cylindrical surfaces. The outer diameters of the first end 22 and the second end 24 are equal, and as shown in FIG. 2, the first end is connected by a half-pipe-shaped intermediate portion 26 having the same outer diameter. The portion 22, the second end portion 24, and the intermediate portion 26 are integrally formed with the plate-shaped body portion 12B.

図４に示されるように、中心軸部１６は、半月状の押え板２８の中央付近から突出するように押え板２８と一体で形成されている。なお、中心軸部１６及び押え板２８の材料も例えば合成樹脂である。ケーシング３０には押え板２８が嵌合する凹部３０Ａが形成されている。この凹部３０Ａに嵌合した押え板２８の上に透視窓３２が設置されており、ケーシング３０と透視窓３２に挟まれて押え板２８はケーシング３０に固定されている。これにより、中心軸部１６は、第１端部２２の近傍において押え板２８を介して片持ち状態で実質的にケーシング３０に支持されている。なお、透視窓３２は、透明な基材に目盛りが設置された構成であり、目盛りによって観察者がフラッパ１２の回転角（流量）を読み取ることができるようになっている。 As shown in FIG. 4, the central shaft portion 16 is integrally formed with the pressing plate 28 so as to project from the vicinity of the center of the half-moon-shaped pressing plate 28. The material of the central shaft portion 16 and the holding plate 28 is also, for example, a synthetic resin. The casing 30 is formed with a recess 30A into which the pressing plate 28 is fitted. A see-through window 32 is installed on the presser plate 28 fitted in the recess 30A, and the presser plate 28 is fixed to the casing 30 by being sandwiched between the casing 30 and the see-through window 32. As a result, the central shaft portion 16 is substantially supported by the casing 30 in a cantilevered state via the pressing plate 28 in the vicinity of the first end portion 22. The perspective window 32 has a structure in which a scale is installed on a transparent base material, and the scale allows the observer to read the rotation angle (flow rate) of the flapper 12.

中心軸部１６は、フラッパ１２の基端部１２Ａの第１端部２２及び第２端部２４を径方向内側から摺動可能に支持している。より詳細には、中心軸部１６は、第１端部２２の内周面と遊嵌している。なお、押え板２８は、環状で先端が丸みを帯びた形状の第１端部２２の側面２２Ａと接触または近接している。図５に拡大して示されるように、中心軸部１６の先端の近傍には他の部分よりも括れた首部が形成されている。この首部よりも先端側の先端部において、中心軸部１６は第２端部２４の凹部２４Ｂに遊嵌している。先端部の外周面１６Ａ（第２端部２４との摺動面）は、第２端部２４の凹部２４Ｂの内周面（中心軸部１６との摺動面）に向かって凸である丸みを帯びた形状である。また、第２端部２４の隔壁２４Ａの第１端部２２の側の面である軸方向規制面２４Ｄは、中心軸部１６の先端部の軸方向の先端面１６Ｂと接触または近接している。中心軸部１６の先端面１６Ｂも軸方向規制面２４Ｄに向かって凸である丸みを帯びた形状である。また、第２端部２４における第１端部２２から離れる側の側面２４Ｅ（基端部１２Ａの軸方向の端面）は、回転中心１４に同軸的な環状であり、且つ、回転中心１４を含む断面における形状がケーシング３０（接触または近接する他の部材）の内周面に向かって凸である丸みを帯びた形状である。なお、中心軸部１６は、図５に示される押え板２８を除く部分の断面形状が回転中心１４の回りに回転した回転体形状である。 The central shaft portion 16 slidably supports the first end portion 22 and the second end portion 24 of the base end portion 12A of the flapper 12 from the inside in the radial direction. More specifically, the central shaft portion 16 is loosely fitted with the inner peripheral surface of the first end portion 22. The pressing plate 28 is in contact with or in close proximity to the side surface 22A of the first end portion 22 having an annular shape and a rounded tip. As shown in an enlarged manner in FIG. 5, a neck portion that is narrower than the other portions is formed in the vicinity of the tip of the central shaft portion 16. At the tip end side of the neck portion, the central shaft portion 16 is loosely fitted in the recess 24B of the second end portion 24. The outer peripheral surface 16A (sliding surface with the second end portion 24) of the tip portion has a roundness that is convex toward the inner peripheral surface (sliding surface with the central shaft portion 16) of the recess 24B of the second end portion 24. It has a tinged shape. Further, the axial regulation surface 24D, which is a surface of the partition wall 24A of the second end 24 on the side of the first end 22, is in contact with or close to the axial tip surface 16B of the tip of the central shaft 16. .. The tip surface 16B of the central shaft portion 16 also has a rounded shape that is convex toward the axial regulation surface 24D. Further, the side surface 24E (the axial end surface of the base end portion 12A) on the side of the second end portion 24 on the side away from the first end portion 22 is an annular shape coaxial with the rotation center 14 and includes the rotation center 14. The shape in the cross section is a rounded shape that is convex toward the inner peripheral surface of the casing 30 (other members that are in contact with or close to each other). The central shaft portion 16 has a rotating body shape in which the cross-sectional shape of the portion excluding the pressing plate 28 shown in FIG. 5 is rotated around the rotation center 14.

マグネット１８は円板状体であり、第２端部２４の凹部２４Ｃに嵌合し、フラッパ１２と一体で回転するように第２端部２４に固定されている。マグネット１８は、回転中心１４を含む面に対して対称的にＮ極とＳ極とに分極されている。なお、凹部２４Ｃは側面２４Ｅの近傍の部分が他の部分よりも内径が大きい段付き形状である。この内径が大きい部分には樹脂等が充填され、これによりマグネット１８が第２端部２４に固定されている。 The magnet 18 is a disk-shaped body, is fitted in the recess 24C of the second end 24, and is fixed to the second end 24 so as to rotate integrally with the flapper 12. The magnet 18 is polarized symmetrically with respect to the plane including the center of rotation 14 into the north and south poles. The recess 24C has a stepped shape in which the portion near the side surface 24E has a larger inner diameter than the other portions. The portion having a large inner diameter is filled with resin or the like, whereby the magnet 18 is fixed to the second end portion 24.

図４に示されるように、ケーシング３０は略箱状体であり、押え板２８が取付けられる表側壁部が開口し、この開口部は透視窓３２で閉塞されている。一方、裏側壁部には開口部はなく、その内側には、フラッパ１２の基端部１２Ａの第２端部２４の外周面に接触または近接して第２端部２４を径方向外側から回転可能に保持する第２端部外側保持部３４が形成されている（図１参照）。第２端部外側保持部３４は、ケーシング３０の内側の面に形成された円形の凹部である。なお、第２端部２４は、板状体部１２Ｂよりも第１端部２２から離れる側に突出する部分において第２端部外側保持部３４と係合している。また、第２端部２４の側面２４Ｅは、第２端部外側保持部３４の底面と接触または近接している。 As shown in FIG. 4, the casing 30 is a substantially box-shaped body, and the front side wall portion to which the holding plate 28 is attached is opened, and this opening is closed by the see-through window 32. On the other hand, there is no opening in the back side wall, and inside the opening, the second end 24 is rotated from the outside in the radial direction in contact with or close to the outer peripheral surface of the second end 24 of the base end 12A of the flapper 12. A second end outer holding portion 34 for allowing is formed (see FIG. 1). The second end outer holding portion 34 is a circular recess formed on the inner surface of the casing 30. The second end portion 24 is engaged with the second end portion outer holding portion 34 at a portion protruding from the plate-shaped body portion 12B toward the side away from the first end portion 22. Further, the side surface 24E of the second end portion 24 is in contact with or close to the bottom surface of the second end portion outer holding portion 34.

センサ２０は、ケーシング３０の裏側壁部の外側（裏側）に設置されている。センサ２０は、ホール素子、磁気抵抗効果素子、コイル等を備え、マグネット１８の回転角に伴う磁場の変化を検出して電気信号として出力するように構成されている。なお、センサ２０は、マグネット１８の回転角の変化をリニアに検出することができる。 The sensor 20 is installed on the outside (back side) of the back side wall portion of the casing 30. The sensor 20 includes a Hall element, a magnetoresistive effect element, a coil, and the like, and is configured to detect a change in the magnetic field accompanying the rotation angle of the magnet 18 and output it as an electric signal. The sensor 20 can linearly detect a change in the rotation angle of the magnet 18.

ケーシング３０における表側壁部及び裏側壁部とは別の他の対向する２つの壁部には管状の入口部と出口部が形成されている。フラッパ式流量検出器１０は、これら入口部と出口部において、測定対象である流体が流れる配管に接続され、フラッパ１２が設置されたケーシング３０の内側の流路を流体が流れるように構成されている。なお、フラッパ１２はねじりコイルばね等の付勢手段（図示省略）により、ケーシング３０の内側の流路を閉塞する側に付勢されている。 A tubular inlet and outlet are formed on two opposing walls of the casing 30, which are separate from the front side wall and the back side wall. The flapper type flow rate detector 10 is connected to a pipe through which the fluid to be measured flows at these inlets and outlets, and is configured so that the fluid flows through the flow path inside the casing 30 in which the flapper 12 is installed. There is. The flapper 12 is urged on the side that closes the flow path inside the casing 30 by an urging means (not shown) such as a torsion coil spring.

次に、フラッパ式流量検出器１０の作用効果について説明する。フラッパ式流量検出器１０は、中心軸部１６、マグネット１８及びセンサ２０が、この順で軸方向に並んで設置されるので、回転中心１４の径方向に小型化しやすい。また、中心軸部１６、マグネット１８及びセンサ２０は、軸方向に相互に離間して設置されているので、マグネット１８やセンサ２０に孔を形成して中心軸部１６を挿通する必要がない。したがって、構造が簡単で組立て作業が容易である Next, the operation and effect of the flapper type flow rate detector 10 will be described. In the flapper type flow rate detector 10, since the central shaft portion 16, the magnet 18, and the sensor 20 are installed side by side in the axial direction in this order, it is easy to miniaturize in the radial direction of the rotation center 14. Further, since the central shaft portion 16, the magnet 18 and the sensor 20 are installed so as to be separated from each other in the axial direction, it is not necessary to form a hole in the magnet 18 or the sensor 20 to insert the central shaft portion 16. Therefore, the structure is simple and the assembly work is easy.

また、フラッパ１２の基端部１２Ａを径方向内側から摺動可能に支持する中心軸部１６が片持ち状態で実質的にケーシング３０に支持される構成であるので、フラッパ１２をケーシング３０に組み付ける際、フラッパ１２、中心軸部１６を軸方向のみに移動させればよく、フラッパ１２を径方向に移動させる必要がないので、この点でも径方向に小型化しやすく、また、組立て作業が容易である。さらに、第２端部２４を径方向外側から回転可能に保持する第２端部外側保持部３４が備えられているので、中心軸部１６が第１端部２２の近傍において片持ち状態で支持される構成であっても、フラッパ１２の径方向の振れを抑制できる。 Further, since the central shaft portion 16 that slidably supports the base end portion 12A of the flapper 12 from the inside in the radial direction is substantially supported by the casing 30 in a cantilevered state, the flapper 12 is assembled to the casing 30. At this time, the flapper 12 and the central shaft portion 16 need only be moved in the axial direction, and it is not necessary to move the flapper 12 in the radial direction. Therefore, in this respect as well, it is easy to miniaturize in the radial direction and the assembly work is easy. is there. Further, since the second end outer holding portion 34 that rotatably holds the second end 24 from the outer side in the radial direction is provided, the central shaft portion 16 is supported in a cantilever state in the vicinity of the first end 22. Even with this configuration, the radial runout of the flapper 12 can be suppressed.

また、中心軸部１６が第２端部２４も径方向内側から摺動可能に支持する構成であるので、フラッパ１２の径方向の振れを抑制する効果がさらに高められている。また、中心軸部１６における先端部の外周面１６Ａ（第２端部２４との摺動面）が、第２端部２４の凹部２４Ｂの内周面（中心軸部１６との摺動面）に向かって凸である丸みを帯びた形状であるので、中心軸部１６と第２端部２４との摺動部の接触面積が小さく、摺動抵抗を低減できる。さらに、フラッパ１２や中心軸部１６が径方向に振れた場合でも、中心軸部１６と第２端部２４との摺動抵抗の増大を防止または抑制できる。 Further, since the central shaft portion 16 also slidably supports the second end portion 24 from the inside in the radial direction, the effect of suppressing the radial runout of the flapper 12 is further enhanced. Further, the outer peripheral surface 16A (sliding surface with the second end portion 24) of the tip portion of the central shaft portion 16 is the inner peripheral surface (sliding surface with the central shaft portion 16) of the recess 24B of the second end portion 24. Since it has a rounded shape that is convex toward, the contact area between the sliding portion between the central shaft portion 16 and the second end portion 24 is small, and the sliding resistance can be reduced. Further, even when the flapper 12 and the central shaft portion 16 swing in the radial direction, it is possible to prevent or suppress an increase in the sliding resistance between the central shaft portion 16 and the second end portion 24.

また、第２端部２４が中心軸部１６の軸方向の先端面１６Ｂと接触または近接する軸方向規制面２４Ｄを備えるので、フラッパ１２の第１端部２２側への移動を中心軸部１６によって規制することができる。また、中心軸部１６の先端面１６Ｂが、軸方向規制面２４Ｄに向かって凸である丸みを帯びた形状であるので、中心軸部１６の先端面１６Ｂと第２端部２４の軸方向規制面２４Ｄとの接触面積が小さく、摺動抵抗を低減できる。さらに、フラッパ１２や中心軸部１６が径方向に振れた場合でも、中心軸部１６の先端面１６Ｂと第２端部２４の軸方向規制面２４Ｄとの摺動抵抗の増大を防止または抑制できる。 Further, since the second end portion 24 includes the axial regulation surface 24D which is in contact with or close to the axial tip surface 16B of the central shaft portion 16, the movement of the flapper 12 to the first end portion 22 side is performed by the central shaft portion 16. Can be regulated by. Further, since the tip surface 16B of the central shaft portion 16 has a rounded shape that is convex toward the axial regulation surface 24D, the tip surface 16B of the central shaft portion 16 and the second end portion 24 are regulated in the axial direction. The contact area with the surface 24D is small, and the sliding resistance can be reduced. Further, even when the flapper 12 or the central shaft portion 16 swings in the radial direction, it is possible to prevent or suppress an increase in the sliding resistance between the tip surface 16B of the central shaft portion 16 and the axial regulation surface 24D of the second end portion 24. ..

また、フラッパ１２は第１端部２２の側面２２Ａ及び第２端部２４の側面２４Ｅ（基端部１２Ａの軸方向の端面）が回転中心１４に同軸的な環状であり、且つ、回転中心１４を含む断面における形状が、押え板２８またはケーシング３０（接触または近接する他の部材）に向かって凸である丸みを帯びた形状であるので、フラッパ１２の基端部１２Ａと押え板２８またはケーシング３０との接触面積が小さく、摺動抵抗を低減できる。さらに、フラッパ１２が径方向に振れた場合でも、第１端部２２の側面２２Ａ及び第２端部２４の側面２４Ｅと押え板２８またはケーシング３０との摺動抵抗の増大を防止または抑制できる。 Further, the flapper 12 has an annular shape in which the side surface 22A of the first end portion 22 and the side surface 24E of the second end portion 24 (the axial end surface of the base end portion 12A) are coaxial with the rotation center 14, and the rotation center 14 Since the shape in the cross section including the flapper 12 is a rounded shape that is convex toward the presser plate 28 or the casing 30 (other members in contact with or in close proximity to), the base end portion 12A of the flapper 12 and the presser plate 28 or the casing The contact area with 30 is small, and the sliding resistance can be reduced. Further, even when the flapper 12 swings in the radial direction, it is possible to prevent or suppress an increase in sliding resistance between the side surface 22A of the first end portion 22 and the side surface 24E of the second end portion 24 and the pressing plate 28 or the casing 30.

なお、本実施形態において、フラッパ１２は第１端部２２の側面２２Ａ及び第２端部２４の側面２４Ｅ（基端部１２Ａの軸方向の端面）の両方が、押え板２８またはケーシング３０（接触または近接する他の部材）に向かって凸である丸みを帯びた形状であるが、いずれか一方のみが、接触または近接する他の部材に向かって凸である丸みを帯びた形状であってもよい。例えば、フラッパ１２が第１端部２２側に移動する際に第１端部２２の側面２２Ａが押え板２８に接触する前に第２端部２４の軸方向規制面２４Ｄが中心軸部１６の軸方向の先端面１６Ｂと接触する場合、第１端部２２の側面２２Ａは、押え板２８に向かって凸である丸みを帯びた形状でなくてもよい。 In the present embodiment, both the side surface 22A of the first end portion 22 and the side surface 24E of the second end portion 24 (the axial end surface of the base end portion 12A) of the flapper 12 are the pressing plate 28 or the casing 30 (contact). Or a rounded shape that is convex towards the other member in close proximity), but only one of them has a rounded shape that is convex towards the other member in contact or proximity. Good. For example, when the flapper 12 moves to the first end 22 side, the axial regulation surface 24D of the second end 24 is set on the central shaft 16 before the side surface 22A of the first end 22 comes into contact with the pressing plate 28. When in contact with the tip surface 16B in the axial direction, the side surface 22A of the first end portion 22 does not have to have a rounded shape that is convex toward the pressing plate 28.

また、本実施形態において、中心軸部１６の先端面１６Ｂは第２端部２４の軸方向規制面２４Ｄに向かって凸である丸みを帯びた形状であるが、先端面１６Ｂは平坦で、軸方向規制面２４Ｄが先端面１６Ｂに向かって凸である丸みを帯びた形状であってもよい。また、先端面１６Ｂ及び軸方向規制面２４Ｄの両方が相手側に向かって凸である丸みを帯びた形状であってもよい。また、例えば、フラッパ１２が第１端部２２側に移動する際に軸方向規制面２４Ｄが先端面１６Ｂに接触する前に第１端部２２の側面２２Ａが押え板２８に接触する場合、先端面１６Ｂ及び軸方向規制面２４Ｄの両方が平坦であってもよい。また例えば、フラッパ１２の第１端部２２及び第２端部２４と、押え板２８、ケーシング３０または中心軸部１６との軸方向の接触による摺動抵抗が問題とならない場合には、中心軸部１６の先端面１６Ｂ、第２端部２４の軸方向規制面２４Ｄ、第１端部２２の側面２２Ａ及び第２端部２４の側面２４Ｅの全部または一部が丸みを帯びた形状でなくてもよい。 Further, in the present embodiment, the tip surface 16B of the central shaft portion 16 has a rounded shape that is convex toward the axial regulation surface 24D of the second end portion 24, but the tip surface 16B is flat and has a shaft. The direction control surface 24D may have a rounded shape that is convex toward the tip surface 16B. Further, both the tip surface 16B and the axial regulation surface 24D may have a rounded shape that is convex toward the mating side. Further, for example, when the side surface 22A of the first end portion 22 contacts the pressing plate 28 before the axial regulation surface 24D contacts the tip surface 16B when the flapper 12 moves to the first end portion 22 side, the tip end. Both the surface 16B and the axial regulation surface 24D may be flat. Further, for example, when the sliding resistance due to the axial contact between the first end portion 22 and the second end portion 24 of the flapper 12 and the pressing plate 28, the casing 30, or the central shaft portion 16 does not matter, the central shaft The tip surface 16B of the portion 16, the axial regulation surface 24D of the second end portion 24, the side surface 22A of the first end portion 22, and the side surface 24E of the second end portion 24 are not all or part of a rounded shape. May be good.

また、本実施形態において、中心軸部１６の先端部の外周面１６Ａ（第２端部２４との摺動面）は、第２端部２４の凹部２４Ｂの内周面（中心軸部１６との摺動面）に向かって凸である丸みを帯びた形状であるが、第２端部２４の凹部２４Ｂの内周面が中心軸部１６の先端部の外周面１６Ａに向かって凸である丸みを帯びた形状であり、中心軸部１６の先端部の外周面１６Ａは円筒面であってもよい。また、第２端部２４の凹部２４Ｂの内周面及び中心軸部１６の先端部の外周面１６Ａの両方が相手に向かって凸である丸みを帯びた形状であってもよい。また例えば、第２端部２４の凹部２４Ｂの内周面と中心軸部１６の先端部の外周面１６Ａとの摺動抵抗が問題とならない場合には、第２端部２４の凹部２４Ｂの内周面及び中心軸部１６の先端部の外周面１６Ａの両方が円筒面であってもよい。 Further, in the present embodiment, the outer peripheral surface 16A (sliding surface with the second end portion 24) of the tip portion of the central shaft portion 16 is the inner peripheral surface (with the central shaft portion 16) of the recess 24B of the second end portion 24. It has a rounded shape that is convex toward the sliding surface), but the inner peripheral surface of the recess 24B of the second end 24 is convex toward the outer peripheral surface 16A of the tip of the central shaft portion 16. It has a rounded shape, and the outer peripheral surface 16A of the tip end portion of the central shaft portion 16 may be a cylindrical surface. Further, both the inner peripheral surface of the concave portion 24B of the second end portion 24 and the outer peripheral surface 16A of the tip end portion of the central shaft portion 16 may have a rounded shape that is convex toward the other party. Further, for example, when the sliding resistance between the inner peripheral surface of the recess 24B of the second end 24 and the outer peripheral surface 16A of the tip of the central shaft 16 does not matter, the inside of the recess 24B of the second end 24 Both the peripheral surface and the outer peripheral surface 16A of the tip end portion of the central shaft portion 16 may be cylindrical surfaces.

また、本実施形態において、中心軸部１６が第２端部２４も径方向内側から摺動可能に支持する構成であるが、フラッパ１２の径方向の振れを抑制できれば、中心軸部１６は第１端部２２のみを径方向内側から摺動可能に支持する構成であってもよい。 Further, in the present embodiment, the central shaft portion 16 is configured to slidably support the second end portion 24 from the inside in the radial direction, but if the radial runout of the flapper 12 can be suppressed, the central shaft portion 16 will be the first. Only one end 22 may be slidably supported from the inside in the radial direction.

また、本実施形態において、第２端部２４を径方向外側から回転可能に保持する第２端部外側保持部３４が備えられているが、フラッパ１２の径方向の振れを抑制できれば、第２端部外側保持部３４を備えない構成としてもよい。 Further, in the present embodiment, the second end portion outer holding portion 34 for rotatably holding the second end portion 24 from the radial outer side is provided, but if the radial runout of the flapper 12 can be suppressed, the second end portion 24 is provided. The configuration may not include the end outer holding portion 34.

また、本実施形態において、中心軸部１６は押え板２８と一体で形成され、押え板２８を介して片持ち状態で実質的にケーシング３０に支持されているが、中心軸部は押え板と別体で形成されて押え板に結合され、押え板を介して片持ち状態で実質的にケーシングに支持される構成でもよい。また、中心軸部は押え板とは別の部材と一体または別体で形成され、この部材を介して片持ち状態で実質的にケーシングに支持される構成でもよい。また、中心軸部は、片持ち状態でケーシングに直接支持される構成でもよい。 Further, in the present embodiment, the central shaft portion 16 is formed integrally with the pressing plate 28 and is substantially supported by the casing 30 in a cantilevered state via the pressing plate 28, but the central shaft portion is formed with the pressing plate 28. It may be formed as a separate body, coupled to a pressing plate, and substantially supported by the casing in a cantilevered state via the pressing plate. Further, the central shaft portion may be formed integrally or separately from a member different from the holding plate, and may be substantially supported by the casing in a cantilevered state via this member. Further, the central shaft portion may be configured to be directly supported by the casing in a cantilevered state.

また、本実施形態において、センサ２０は、マグネット１８の回転角の変化をリニアに検出することができるが、センサ２０は、マグネット１８の回転角が所定の閾値に達したことを検出するスイッチタイプのものであってもよい。 Further, in the present embodiment, the sensor 20 can linearly detect the change in the rotation angle of the magnet 18, but the sensor 20 is a switch type that detects that the rotation angle of the magnet 18 has reached a predetermined threshold value. It may be.

本発明は、設備や機械において空気や水等の流体の流量を検出するために利用できる。 The present invention can be used to detect the flow rate of a fluid such as air or water in equipment or machinery.

１０フラッパ式流量検出器
１２フラッパ
１２Ａ基端部
１４回転中心
１６中心軸部
１６Ａ外周面（第２端部との摺動面）
１６Ｂ先端面
１８マグネット
２０センサ
２２第１端部
２２Ａ側面（端面）
２４第２端部
２４Ｄ軸方向規制面
２４Ｅ側面（端面）
２６中間部
２８押え板
３０ケーシング
３２透視窓
３４第２端部外側保持部10 Flapper type flow rate detector 12 Flapper 12A Base end 14 Rotation center 16 Central shaft 16A Outer peripheral surface (sliding surface with the second end)
16B Tip surface 18 Magnet 20 Sensor 22 First end 22A Side surface (end face)
24 2nd end 24D Axial regulation surface 24E Side surface (end surface)
26 Intermediate part 28 Pressing plate 30 Casing 32 Perspective window 34 Second end outer holding part

Claims

A flapper installed so that the rotation angle changes according to the flow rate of the fluid to be measured,
A central shaft portion that slidably supports the base end portion on the rotation center side of the flapper from the inside in the radial direction,
A magnet installed at a position coaxial with the center of rotation of the flapper so that it rotates integrally with the flapper.
A sensor for detecting the rotation angle of the magnet is provided.
A flapper type flow rate detector, wherein the central shaft portion, the magnet, and the sensor are arranged in this order in the axial direction and are separated from each other in the axial direction.

In claim 1,
Of the first end on one side and the second end on the other side in the axial direction at the base end of the flapper, the diameter of the second end is in contact with or close to the outer peripheral surface of the second end. Further provided with a second end outer holding portion that rotatably holds from the outside in the direction,
The central shaft portion slidably supports at least the first end portion of the first end portion and the second end portion from the inside in the radial direction, and is cantilevered in the vicinity of the first end portion. Substantially supported by the casing,
The magnet is a flapper type flow rate detector, characterized in that it is installed at the second end portion.

In claim 2,
The central shaft portion also slidably supports the second end portion from the inside in the radial direction.
One of the sliding surface with the second end portion of the central shaft portion and the sliding surface with the central shaft portion at the second end portion has a shape in a cross section including the rotation center convex toward the other. A flapper type flow rate detector characterized by having a certain rounded shape.

In claim 2 or 3,
The central shaft portion also slidably supports the second end portion from the inside in the radial direction.
The second end portion comprises an axial regulation surface that is in contact with or close to the axial tip surface of the central shaft portion.
A flapper type flow rate detector, characterized in that one of the tip surface of the central shaft portion and the axial regulation surface of the second end portion has a rounded shape that is convex toward the other.

In any of claims 1 to 4,
The flapper is restricted from moving in the axial direction in contact with or in close proximity to other members on both end faces of the base end portion in the axial direction.
The end face of the base end portion on at least one side in the axial direction is an annular shape coaxial with the rotation center, and the shape in the cross section including the rotation center is convex toward the contacting or adjacent other member. A flapper type flow rate detector characterized by having a certain rounded shape.