JP3771046B2 - Load cell type weighing device and load cell - Google Patents

Load cell type weighing device and load cell Download PDF

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JP3771046B2
JP3771046B2 JP11282598A JP11282598A JP3771046B2 JP 3771046 B2 JP3771046 B2 JP 3771046B2 JP 11282598 A JP11282598 A JP 11282598A JP 11282598 A JP11282598 A JP 11282598A JP 3771046 B2 JP3771046 B2 JP 3771046B2
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load cell
fixed
bolt
movable
protruding
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JPH11295162A (en
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道人 宇都宮
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Ishida Co Ltd
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Ishida Co Ltd
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Description

【０００１】
【発明の属する技術分野】
本発明はロードセルの取付構造に関するものである。
【０００２】
【従来の技術】
従来のロードセルの一般的な取付構造を図６に示す。
図７において、ロードセル式計量装置１は中央に中空部２０を有するロードセル（起歪体）２の４つの起歪部２３の表面に、歪ゲージのような検出素子３が貼着されてなる。前記ロードセル２は、たとえばアルミ合金製で上下の一対のビーム２４と、該一対のビーム２４の両端を上下に連結する固定部２１および可動部２２とが一体に形成されてなる。前記固定部２１および可動部２２には、各々一対の雌ネジ２００が形成されており、これらの雌ネジ２００に第１および第２ボルト４１，４２がねじ込まれて、前記固定部２１および可動部２２が、それぞれ、第１取付部材５および第２取付部材６にビーム２４の長手方向に締結されている。なお、各ボルト４１，４２の軸線は、それぞれ、ビーム２４の長手方向（軸線方向）に設定されている。また、第２取付部材６の遊端部６０には、被計量物を載置する皿などが取り付けられている。
【０００３】
前記ロードセル式計量装置１は、荷重が負荷されると起歪部２３が変形して、該起歪部２３の表面の歪みを４つの検出素子３の電気抵抗の変化によって検出することで、被計量物の重量が測定される。かかるロードセル式計量装置１においては、前記各ボルト４１，４２の締結力（軸力）によりロードセル２の内部に応力が発生し、該応力が起歪部２３に伝達される。そのため、重量の測定に際し、ロードセル２から検出素子３への歪伝達にヒステリシスなどの悪影響が生じ、計量精度が低下することは、既に知られている（実開昭５４−１８０７６９号、特許第２６３８４５９号）。
【０００４】
そこで、かかるボルト４１，４２の締結力による悪影響を減少させる手段として、図８に示すロードセル式計量装置１の取付構造が知られている。図８のロードセル２には、ボルト４１，４２とビーム２４との間に溝２０１が設けられており、ボルト４１，４２の締結力により発生した応力が起歪部２３に伝わるのを、前記溝２０１によって遮断している。
【０００５】
【発明が解決しようとする課題】
しかし、この従来技術では、固定部２１および可動部２２に溝２０１を刻設しているので、ロードセル２が左右に大型化するのは避けられない。一方、近年、ロードセルを組み込む計量機器は小型化される傾向にあり、また、モータ、配線基板などの電気部品やリンクなどの機械要素をロードセル２と共に筐体内に組み込む場合が多く、ロードセル２を小型化することは重要である。
【０００６】
したがって、本発明の目的は、ボルトの締結力による計量精度の低下を防止し得ると共に、ロードセルの小型化を図ることである。
【０００７】
【課題を解決するための手段】
前記目的を達成するために、本第１発明のロードセル式計量装置は、一対の平行なビームの両端を互いに固定部および可動部で上下に一体に連ねると共に、固定部または可動部の少なくとも一方を取付部材に対してビームの長手方向にボルトで締結してなるロードセル式計量装置において、固定部または可動部の少なくとも一方からロードセルの中空部に向って突出する突出部または突出部材を設け、該突出部または突出部材を固定部または可動部の少なくとも一方を介して取付部材に固定したことを特徴とする。
【０００８】
本第１発明によれば、突出部または突出部材を固定部または可動部を介して取付部材に固定しているから、固定部または可動部に雌ネジ部を設けないので、ビームの起歪部に雌ネジ部からの応力が伝達されにくくなる。
【０００９】
一方、本第２発明のロードセル式計量装置は、一対の平行なビームの両端を互いに固定部および可動部で上下に一体に連ねると共に、固定部または可動部の少なくとも一方を取付部材に対してビームの長手方向にボルトで締結してなるロードセル式計量装置において、固定部または可動部の少なくとも一方からロードセルの中空部に向って突出する突出部または突出部材を設け、該突出部または突出部材に形成した雌ネジ部にボルトをねじ込んで固定部または可動部の少なくとも一方を取付部材に締結したことを特徴とする。
【００１０】
本第２発明によれば、ボルトの締結力を生み出す雌ネジ部が、固定部または可動部から中空部に向って突出しており、つまり、締結力を発揮する雌ネジ部が固定部または可動部よりも一対のビームの内側に入り込んでいるから、雌ネジ部とビームとの間に中空部が介在するので、雌ネジ部から前記ビームの起歪部に応力が伝達されにくくなる。
【００１１】
本第３発明のロードセルは、一対の平行なビームの両端を互いに固定部および可動部で上下に一体に連ねたロードセルであって、固定部または可動部の少なくとも一方におけるビームの外側には、固定部または可動部の少なくとも一方を取付部材に対してビームの長手方向に締結するボルトを挿通可能とするボルト挿通孔が形成され、該ボルト挿通孔におけるビームの外側の部分には雌ネジが形成されていないことを特徴とする。
【００１２】
本発明において、ビームの起歪部に伝達される応力は、ボルトに螺合する雌ネジ部から発生する。したがって、本第３発明のロードセルのように、ビームの外側の部分に雌ネジを形成しなければ、ビームの起歪部に応力が伝達されにくくなる。
【００１３】
【発明の実施の形態】
以下、本発明の実施形態を図面にしたがって説明する。
以下の実施形態のロードセル式計量装置１の基本的な構造等は、前記図６の従来例と同様であり、主に、相違する部分について説明する。
【００１４】
図１は第１実施形態を示す。
この第１実施形態では、中空部２０を略Ｈ字状に形成して、固定部２１および可動部２２から、一対のビーム２４の内側の中空部２０に向って突出する突出部２１ａ，２２ａを設けると共に、該突出部２１ａ，２２ａを固定部２１および可動部２２に一体に形成している。該固定部２１および可動部２２は、一対のビーム２４の外側に位置しており、該固定部２１および可動部２２には、ボルト４１，４２の雄ネジ部よりも径大なボルト挿通孔２５が形成されている。一方、前記ビーム２４の内側に設けられた突出部２１ａ，２２ａには、各ボルト４１，４２がねじ込まれる雌ネジ部２６が形成されており、該雌ネジ部２６にボルト４１，４２がねじ込まれることにより、前記固定部２１および可動部２２が第１および第２取付部材５，６に締結されている。
【００１５】
前記構成においては、雌ネジ部２６が中空部２０に突出した突出部２１ａ，２２ａに形成されているから、つまり、雌ネジ部２６を一対のビーム２４の内側に配設したから、ロードセル２を左右に小型化しても、雌ネジ部２６から起歪部２３までの応力伝達の経路を十分に長くとることができる。したがって、雌ネジ部２６から発生する内部応力が起歪部２３に伝達されるのを抑制し得ると共に、ロードセル２の小型化を図り得る。
【００１６】
ここで、本明細書において、「一対のビーム２４の内側」とは、２本のビーム２４，２４によって挟まれた空間をいい、一方、「一対のビーム２４の外側」とは、前記内側よりもロードセル２の外方寄りの部分をいう。また、「雌ネジ部２６を内側に設け、ボルト挿通孔２５を外側に設ける」とは、前記雌ネジ部２６とボルト挿通孔２５との境界が、ビーム２４の内側と外側との境界線Ｌ上または境界線の近傍にある場合の他に、前記ボルト挿通孔２５が突出部２１ａ，２２ａに入り込んで、境界線Ｌよりも内側までボルト挿通孔２５が存在する場合も含む。また、「ボルト４１，４２の雄ネジ部よりも径大なボルト挿通孔２５」とは、ボルト４１，４２が挿通すると共に螺合（係合）しない孔であることを意味する。
【００１７】
図２は第２実施形態を示す。
前記図１の実施形態では、ビーム２４の両端部に薄肉の起歪部２３が形成されていたが、図２の第２実施形態ではビーム２４の両端部よりも若干内方に寄った位置に起歪部２３が形成されている。換言すれば、図６の従来のロードセル２の中空部２０からボルト４１，４２の軸線に沿って一対の各ボルト４１，４１（ボルト４２，４２）と起歪部２３との間に、図２の溝２０ａを延設すると共に、ボルト挿通孔２５を設けたものである。
【００１８】
図３は第３実施形態を示す。
図３において、この実施形態では、突出部２１ａ，２２ａと固定部２１および可動部２２にボルト挿通孔２５が形成されている。前記突出部２１ａ，２２ａから突出した各ボルト４１，４２の先端部には、突出部材７に形成した雌ネジ部２６が螺合している。該突出部材７は、固定部２１または可動部２２の一方からロードセル２の中空部２０に向って突出していると共に、前記固定部２１および可動部２２とは別体に形成されている。なお、本実施形態では、各突出部材７に一対の雌ネジ部２６が形成されている。その他の構成は図１の第１実施形態と同様であり、同一部分または相当部分に同一符号を付して、その説明を省略する。
【００１９】
図４は第４実施形態を示す。
この実施形態は、図３の実施形態の突出部２１ａ，２２ａを設けずに、前記突出部材７と同じ構造の突出部材７を一対のビーム２４の内側の中空部２０に突出して設けたものである。
【００２０】
図５は第５実施形態を示す。
図５の実施形態は、図４の突出部材７に代えて、図５の固定部２１および可動部２２のボルト挿通孔２５に合致するボルト挿通孔２５を有する挟付部材（突出部材を構成する）７Ｂを設けると共に、各ボルト４１，４２の先端部に螺合するナット（突出部材）４１ａ，４２ａを設けている。
【００２１】
なお、図４の突出部材７および図５の挟付部材７Ｂとしては、ロードセル２を構成する材料よりもヤング率の大きい素材（たとえばステンレス鋼）を用いるのが好ましい。このように、ヤング率の大きい素材を用いることにより、ボルト４１，４２の軸力による突出部材７または挟付部材７Ｂの変形が小さくなるので、検出素子３にボルト４１，４２の締結力が影響したとしても、一対のビーム２４の上下において均等に作用するからである。
【００２２】
図６（ａ）は第６実施形態を示す。
図６（ａ）の実施形態は、ボルト４１，４２を中空部２０から挟持部材７Ｂを介して固定部２１または可動部２２のボルト挿通孔２５に挿入して、該ボルト４１，４２の締結力を発揮する雄ネジ部４１ｂ，４２ｂを第１または第２取付部材５，６まで突出している。前記ボルト４１，４２の頭部４１ｃ，４２ｃおよび前記挟持部材７Ｂは、本発明の突出部材を構成しており、該ボルト４１，４２の雄ネジ部４１ｂ，４２ｂはナット４１ａ，４２ａに螺合している。
なお、前記ナット４１ａ，４２ａに代えて、図６（ｂ）のように、第１または第２取付部材５，６に雌ネジ部５ａ，６ａを形成して、該雌ネジ部５ａ，６ａにボルト４１，４２をねじ込んで、ボルト４１，４２を第１および第２取付部材５，６に固定してもよい。
【００２３】
また、前記実施形態では、固定部２１および可動部２２の双方をボルト４１，４２によりビーム２４の長手方向に固定したが、本発明では固定部２１または可動部２２の少なくとも一方をボルト４１，４２によりビーム２４の長手方向に固定すればよく、他方はビーム２４の長手方向に直交する方向に固定してもよい（たとえば、特許第２６３８４５９号参照）。また、本発明では、ビーム２４に起歪部２３を形成せずにビーム２４に検出素子３を設けてもよい。
【００２４】
【発明の効果】
以上説明したように、本第１発明によれば、突出部または突出部材を固定部または可動部を介して取付部材に固定しているから、固定部または可動部に雌ネジ部を設けないので、ロードセルをビームの長手方向に小型化しても、前記雌ネジ部から検出素子までの応力の伝達経路を十分に長くとることができる。したがって、雌ネジ部で発生した応力が検出素子に伝達されるのを抑制して、計量精度の向上を図り得ると共に、ロードセルの小型化を図り得る。
【００２５】
また、本第２発明によれば、ボルトの締結力を受ける雌ネジ部が固定部または可動部から中空部に突出した突出部または突出部材に形成されているから、締結力を発揮する雌ネジ部が一対のビームの内側に入り込んでいるので、ロードセルをビームの長手方向に小型化しても、前記雌ネジ部から検出素子までの応力の伝達経路を十分に長くとることができる。したがって、雌ネジ部で発生した応力が検出素子に伝達されるのを抑制して、計量精度の向上を図り得ると共に、ロードセルの小型化を図り得る。
【図面の簡単な説明】
【図１】本発明の第１実施形態にかかるロードセルの取付構造を示す断面図である。
【図２】第２実施形態にかかるロードセルの取付構造を示す断面図である。
【図３】第３実施形態にかかるロードセルの取付構造を示す断面図である。
【図４】第４実施形態にかかるロードセルの取付構造を示す断面図である。
【図５】第５実施形態にかかるロードセルの取付構造を示す断面図である。
【図６】第６実施形態にかかるロードセルの取付構造を示す断面図である。
【図７】従来の一般的なロードセルの取付構造を示す断面図である。
【図８】他のロードセルの取付構造を示す断面図である。
【符号の説明】
１：ロードセル式計量装置
２：ロードセル
２０：中空部
２１：固定部
２２：可動部
２１ａ，２２ａ：突出部
４１ｃ，４２ｃ：突出部材
２４：ビーム
２５：ボルト挿通孔
２６：雌ネジ部
４１：ボルト
４２：ボルト
５：第１取付部材
６：第２取付部材
７：突出部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a load cell mounting structure.
[0002]
[Prior art]
A general mounting structure of a conventional load cell is shown in FIG.
In FIG. 7, the load cell type measuring device 1 has a detection element 3 such as a strain gauge attached to the surface of four strain generating portions 23 of a load cell (strain generating body) 2 having a hollow portion 20 in the center. The load cell 2 is made of, for example, an aluminum alloy, and is formed by integrally forming a pair of upper and lower beams 24 and a fixed portion 21 and a movable portion 22 that vertically connect both ends of the pair of beams 24. The fixed portion 21 and the movable portion 22 are each formed with a pair of female screws 200, and first and second bolts 41 and 42 are screwed into the female screws 200, and the fixed portion 21 and the movable portion 22 22 are fastened to the first mounting member 5 and the second mounting member 6 in the longitudinal direction of the beam 24, respectively. The axial lines of the bolts 41 and 42 are set in the longitudinal direction (axial direction) of the beam 24, respectively. In addition, a plate or the like for placing an object to be weighed is attached to the free end portion 60 of the second attachment member 6.
[0003]
The load cell type measuring device 1 deforms the strain generating portion 23 when a load is applied, and detects the strain on the surface of the strain generating portion 23 by the change in the electric resistance of the four detection elements 3, thereby The weight of the weighing object is measured. In the load cell type measuring device 1, stress is generated inside the load cell 2 by the fastening force (axial force) of the bolts 41 and 42, and the stress is transmitted to the strain generating portion 23. For this reason, it is already known that when measuring the weight, the strain transmission from the load cell 2 to the detection element 3 has an adverse effect such as hysteresis, and the measurement accuracy is reduced (Japanese Utility Model Publication No. 54-180769, Japanese Patent No. 2638459). issue).
[0004]
Therefore, as a means for reducing the adverse effect due to the fastening force of the bolts 41 and 42, a mounting structure of the load cell type measuring device 1 shown in FIG. 8 is known. In the load cell 2 of FIG. 8, a groove 201 is provided between the bolts 41 and 42 and the beam 24, and the stress generated by the fastening force of the bolts 41 and 42 is transmitted to the strain generating portion 23. It is blocked by 201.
[0005]
[Problems to be solved by the invention]
However, in this prior art, since the groove 201 is engraved in the fixed portion 21 and the movable portion 22, it is inevitable that the load cell 2 increases in size from side to side. On the other hand, in recent years, weighing devices incorporating a load cell tend to be miniaturized, and electrical components such as motors and wiring boards and mechanical elements such as links are often incorporated in a housing together with the load cell 2, and the load cell 2 is small. Is important.
[0006]
Accordingly, an object of the present invention is to prevent a reduction in measurement accuracy due to a fastening force of a bolt and to reduce the size of a load cell.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the load cell type weighing device according to the first aspect of the present invention is configured such that both ends of a pair of parallel beams are integrally connected to each other by a fixed portion and a movable portion, and at least one of the fixed portion and the movable portion is connected. In a load cell type weighing device that is fastened to a mounting member with a bolt in the longitudinal direction of a beam, a protruding portion or a protruding member that protrudes from at least one of a fixed portion or a movable portion toward a hollow portion of the load cell is provided. The portion or the protruding member is fixed to the mounting member via at least one of the fixed portion or the movable portion.
[0008]
According to the first aspect of the present invention, since the protruding portion or the protruding member is fixed to the mounting member via the fixed portion or the movable portion, the female screw portion is not provided in the fixed portion or the movable portion, so that the beam straining portion It is difficult for stress from the female screw portion to be transmitted.
[0009]
On the other hand, the load cell type measuring device according to the second aspect of the present invention connects both ends of a pair of parallel beams integrally with each other vertically by a fixed portion and a movable portion, and at least one of the fixed portion or the movable portion with respect to the mounting member. In the load cell type weighing device, which is fastened with bolts in the longitudinal direction, a protruding portion or a protruding member protruding from at least one of the fixed portion or the movable portion toward the hollow portion of the load cell is provided, and formed on the protruding portion or the protruding member A bolt is screwed into the female screw portion, and at least one of the fixed portion and the movable portion is fastened to the mounting member.
[0010]
According to the second aspect of the invention, the female screw portion that generates the fastening force of the bolt protrudes from the fixed portion or the movable portion toward the hollow portion, that is, the female screw portion that exhibits the fastening force is the fixed portion or the movable portion. Since the hollow portion is interposed between the female screw portion and the beam, stress is hardly transmitted from the female screw portion to the strain generating portion of the beam.
[0011]
The load cell according to the third aspect of the invention is a load cell in which both ends of a pair of parallel beams are integrally connected to each other vertically by a fixed portion and a movable portion, and is fixed to the outside of the beam in at least one of the fixed portion and the movable portion. A bolt insertion hole is formed through which a bolt for fastening at least one of the movable portion and the movable portion to the mounting member in the longitudinal direction of the beam can be inserted, and a female screw is formed in an outer portion of the beam in the bolt insertion hole. It is characterized by not.
[0012]
In the present invention, the stress transmitted to the strain generating portion of the beam is generated from the female screw portion screwed into the bolt. Therefore, unless a female screw is formed on the outer portion of the beam as in the load cell of the third aspect of the invention, stress is not easily transmitted to the strained portion of the beam.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The basic structure and the like of the load cell type weighing device 1 of the following embodiment are the same as those of the conventional example of FIG. 6, and different parts will be mainly described.
[0014]
FIG. 1 shows a first embodiment.
In the first embodiment, the hollow portion 20 is formed in a substantially H shape, and the protruding portions 21 a and 22 a that protrude from the fixed portion 21 and the movable portion 22 toward the hollow portion 20 inside the pair of beams 24 are provided. The protrusions 21 a and 22 a are formed integrally with the fixed portion 21 and the movable portion 22. The fixed portion 21 and the movable portion 22 are located outside the pair of beams 24, and the fixed portion 21 and the movable portion 22 have a bolt insertion hole 25 having a diameter larger than the male screw portions of the bolts 41 and 42. Is formed. On the other hand, the protruding portions 21a and 22a provided inside the beam 24 are formed with female screw portions 26 into which the bolts 41 and 42 are screwed, and the bolts 41 and 42 are screwed into the female screw portion 26. Thus, the fixed portion 21 and the movable portion 22 are fastened to the first and second attachment members 5 and 6.
[0015]
In the above configuration, since the female screw portion 26 is formed in the protruding portions 21a and 22a protruding from the hollow portion 20, that is, since the female screw portion 26 is disposed inside the pair of beams 24, the load cell 2 is provided. Even if the size is reduced to the left and right, the stress transmission path from the female screw portion 26 to the strain generating portion 23 can be made sufficiently long. Therefore, the internal stress generated from the female screw portion 26 can be suppressed from being transmitted to the strain generating portion 23, and the load cell 2 can be downsized.
[0016]
In this specification, “inside of the pair of beams 24” means a space sandwiched between the two beams 24, 24, while “outside of the pair of beams 24” means from the inside. Also refers to the outward portion of the load cell 2. Further, “providing the female screw part 26 on the inner side and the bolt insertion hole 25 on the outer side” means that the boundary between the female screw part 26 and the bolt insertion hole 25 is a boundary line L between the inner side and the outer side of the beam 24. In addition to the case where it is above or in the vicinity of the boundary line, the case where the bolt insertion hole 25 enters the protruding portions 21a, 22a and the bolt insertion hole 25 exists inside the boundary line L is included. Further, “the bolt insertion hole 25 having a diameter larger than that of the male screw portion of the bolts 41 and 42” means that the bolts 41 and 42 are inserted and are not screwed (engaged).
[0017]
FIG. 2 shows a second embodiment.
In the embodiment of FIG. 1, the thin strain-generating portions 23 are formed at both ends of the beam 24. However, in the second embodiment of FIG. 2, the beam 24 is slightly inward from both ends of the beam 24. A strain generating portion 23 is formed. In other words, between the pair of bolts 41 and 41 (bolts 42 and 42) and the strain generating portion 23 along the axis of the bolts 41 and 42 from the hollow portion 20 of the conventional load cell 2 of FIG. The groove 20a is extended and a bolt insertion hole 25 is provided.
[0018]
FIG. 3 shows a third embodiment.
In FIG. 3, in this embodiment, bolt insertion holes 25 are formed in the protruding portions 21 a and 22 a, the fixed portion 21, and the movable portion 22. A female thread portion 26 formed on the projecting member 7 is screwed to the tip of each bolt 41, 42 projecting from the projecting portion 21a, 22a. The protruding member 7 protrudes from one of the fixed portion 21 and the movable portion 22 toward the hollow portion 20 of the load cell 2 and is formed separately from the fixed portion 21 and the movable portion 22. In the present embodiment, a pair of female screw portions 26 is formed on each protruding member 7. Other configurations are the same as those of the first embodiment of FIG. 1, and the same reference numerals are given to the same or corresponding parts, and the description thereof is omitted.
[0019]
FIG. 4 shows a fourth embodiment.
In this embodiment, the projecting members 7 having the same structure as the projecting member 7 are provided to project into the hollow portions 20 inside the pair of beams 24 without providing the projecting portions 21a and 22a of the embodiment of FIG. is there.
[0020]
FIG. 5 shows a fifth embodiment.
In the embodiment of FIG. 5, instead of the projecting member 7 of FIG. 4, a clamping member (a projecting member) having a bolt insertion hole 25 that matches the bolt insertion hole 25 of the fixed portion 21 and the movable portion 22 of FIG. 5. ) 7B and nuts (protruding members) 41a and 42a that are screwed into the tip ends of the bolts 41 and 42, respectively.
[0021]
In addition, it is preferable to use the raw material (for example, stainless steel) with a larger Young's modulus than the material which comprises the load cell 2 as the protrusion member 7 of FIG. 4, and the clamping member 7B of FIG. In this way, by using a material having a large Young's modulus, deformation of the protruding member 7 or the clamping member 7B due to the axial force of the bolts 41 and 42 is reduced, so that the fastening force of the bolts 41 and 42 affects the detection element 3. Even if it does, it is because it acts on the upper and lower sides of a pair of beam 24 equally.
[0022]
FIG. 6A shows a sixth embodiment.
In the embodiment of FIG. 6A, the bolts 41 and 42 are inserted into the bolt insertion holes 25 of the fixed portion 21 or the movable portion 22 from the hollow portion 20 via the sandwiching member 7B, and the fastening force of the bolts 41 and 42 is as follows. The male screw portions 41b and 42b exhibiting the above are projected to the first or second mounting members 5 and 6. The heads 41c, 42c of the bolts 41, 42 and the clamping member 7B constitute a protruding member of the present invention, and the male screw portions 41b, 42b of the bolts 41, 42 are screwed into the nuts 41a, 42a. ing.
Instead of the nuts 41a and 42a, female screw portions 5a and 6a are formed on the first or second mounting members 5 and 6 as shown in FIG. 6B, and the female screw portions 5a and 6a are formed. The bolts 41 and 42 may be screwed to fix the bolts 41 and 42 to the first and second mounting members 5 and 6.
[0023]
In the above embodiment, both the fixed portion 21 and the movable portion 22 are fixed in the longitudinal direction of the beam 24 by the bolts 41 and 42. However, in the present invention, at least one of the fixed portion 21 or the movable portion 22 is fixed to the bolts 41 and 42. May be fixed in the longitudinal direction of the beam 24, and the other may be fixed in a direction perpendicular to the longitudinal direction of the beam 24 (see, for example, Japanese Patent No. 263859). In the present invention, the detection element 3 may be provided in the beam 24 without forming the strain generating portion 23 in the beam 24.
[0024]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the protruding portion or the protruding member is fixed to the attachment member via the fixed portion or the movable portion, the female screw portion is not provided on the fixed portion or the movable portion. Even if the load cell is downsized in the longitudinal direction of the beam, the stress transmission path from the female screw portion to the detection element can be made sufficiently long. Therefore, it is possible to suppress the stress generated in the female screw portion from being transmitted to the detection element, thereby improving the measurement accuracy and reducing the size of the load cell.
[0025]
Further, according to the second invention, the female screw portion that receives the fastening force of the bolt is formed on the protruding portion or the protruding member that protrudes from the fixed portion or the movable portion to the hollow portion. Since the portion enters the inside of the pair of beams, even if the load cell is downsized in the longitudinal direction of the beam, the stress transmission path from the female screw portion to the detection element can be made sufficiently long. Therefore, it is possible to suppress the stress generated in the female screw portion from being transmitted to the detection element, thereby improving the measurement accuracy and reducing the size of the load cell.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a load cell mounting structure according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a load cell mounting structure according to a second embodiment.
FIG. 3 is a cross-sectional view showing a load cell mounting structure according to a third embodiment.
FIG. 4 is a cross-sectional view showing a load cell mounting structure according to a fourth embodiment.
FIG. 5 is a cross-sectional view showing a load cell mounting structure according to a fifth embodiment.
FIG. 6 is a cross-sectional view showing a load cell mounting structure according to a sixth embodiment.
FIG. 7 is a cross-sectional view showing a conventional general load cell mounting structure.
FIG. 8 is a cross-sectional view showing another load cell mounting structure.
[Explanation of symbols]
1: Load cell type measuring device 2: Load cell 20: Hollow part 21: Fixed part 22: Movable part 21a, 22a: Protruding part 41c, 42c: Protruding member 24: Beam 25: Bolt insertion hole 26: Female thread part 41: Bolt 42 : Bolt 5: First mounting member 6: Second mounting member 7: Projection member

Claims (6)

一対の平行なビームの両端を互いに固定部および可動部で上下に一体に連ねると共に、前記固定部または可動部の少なくとも一方を取付部材に対して前記ビームの長手方向にボルトで締結してなるロードセル式計量装置において、
前記固定部または可動部の少なくとも一方からロードセルの中空部に向って突出する突出部または突出部材を設け、
該突出部または突出部材を前記固定部または可動部の少なくとも一方を介して前記取付部材に固定したことを特徴とするロードセル式計量装置。A load cell in which both ends of a pair of parallel beams are integrally connected to each other vertically by a fixed portion and a movable portion, and at least one of the fixed portion or the movable portion is fastened to a mounting member with a bolt in the longitudinal direction of the beam. In the type weighing device,
Providing a projecting part or projecting member projecting from at least one of the fixed part or the movable part toward the hollow part of the load cell,
The load cell type measuring device, wherein the protruding portion or the protruding member is fixed to the mounting member via at least one of the fixed portion or the movable portion. 一対の平行なビームの両端を互いに固定部および可動部で上下に一体に連ねると共に、前記固定部または可動部の少なくとも一方を取付部材に対して前記ビームの長手方向にボルトで締結してなるロードセル式計量装置において、
前記固定部または可動部の少なくとも一方からロードセルの中空部に向って突出する突出部または突出部材を設け、
該突出部または突出部材に形成した雌ネジ部に前記ボルトをねじ込んで、前記固定部または可動部の少なくとも一方を前記取付部材に締結したことを特徴とするロードセル式計量装置。A load cell in which both ends of a pair of parallel beams are integrally connected to each other vertically by a fixed portion and a movable portion, and at least one of the fixed portion or the movable portion is fastened to a mounting member with a bolt in the longitudinal direction of the beam. In the type weighing device,
Providing a projecting part or projecting member projecting from at least one of the fixed part or the movable part toward the hollow part of the load cell,
A load cell type measuring device, wherein the bolt is screwed into a female screw portion formed on the protruding portion or the protruding member, and at least one of the fixed portion or the movable portion is fastened to the mounting member. 一対の平行なビームの両端を互いに固定部および可動部で上下に一体に連ねると共に、前記固定部または可動部の少なくとも一方を取付部材に対して前記ビームの長手方向にボルトで締結してなるロードセル式計量装置において、
前記固定部または可動部の少なくとも一方からロードセルの中空部に向って突出する突出部または突出部材を設け、
該突出部または突出部材に形成した雌ネジ部に前記ボルトをねじ込んで、前記突出部または突出部材を前記固定部または可動部の少なくとも一方を介して前記取付部材に固定したことを特徴とするロードセル式計量装置。A load cell in which both ends of a pair of parallel beams are integrally connected to each other vertically by a fixed portion and a movable portion, and at least one of the fixed portion or the movable portion is fastened to a mounting member with a bolt in the longitudinal direction of the beam. In the type weighing device,
Providing a projecting part or projecting member projecting from at least one of the fixed part or the movable part toward the hollow part of the load cell,
The load cell, wherein the bolt is screwed into a female screw portion formed on the protruding portion or the protruding member, and the protruding portion or the protruding member is fixed to the mounting member via at least one of the fixed portion or the movable portion. Type weighing device. 請求項１，２もしくは３において、
前記突出部または突出部材を設けた前記固定部または可動部における前記ビームの外側には、前記ボルトが挿通されると共に前記ボルトの雄ネジ部が係合しないボルト挿通孔が形成されているロードセル式計量装置。In claim 1, 2 or 3,
A load cell type in which a bolt insertion hole through which the bolt is inserted and the male screw portion of the bolt is not engaged is formed outside the beam in the fixed portion or the movable portion provided with the protruding portion or the protruding member. Weighing device. 請求項１において、
前記突出部材が前記ボルトの頭部で形成されていると共に、該ボルトの締結力を発揮する雄ネジ部が前記固定部または可動部に挿通されて取付部材まで突出しているロードセル式計量装置。In claim 1,
The load cell type measuring device, wherein the protruding member is formed by a head portion of the bolt, and a male screw portion that exerts a fastening force of the bolt is inserted through the fixed portion or the movable portion and protrudes to the mounting member. 一対の平行なビームの両端を互いに固定部および可動部で上下に一体に連ねたロードセルであって、
前記固定部または可動部の少なくとも一方における前記ビームの外側には、前記固定部または可動部の少なくとも一方を取付部材に対して前記ビームの長手方向に締結するボルトを挿通可能とするボルト挿通孔が形成され、
該ボルト挿通孔における前記ビームの外側の部分には雌ネジが形成されていないことを特徴とするロードセル。A load cell in which both ends of a pair of parallel beams are joined together vertically in a fixed part and a movable part,
A bolt insertion hole through which a bolt that fastens at least one of the fixed portion or the movable portion in the longitudinal direction of the beam with respect to an attachment member can be inserted outside the beam in at least one of the fixed portion or the movable portion. Formed,
A load cell, wherein a female screw is not formed in a portion of the bolt insertion hole outside the beam.
JP11282598A 1998-04-07 1998-04-07 Load cell type weighing device and load cell Expired - Fee Related JP3771046B2 (en)

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JP3818242B2 (en) 2002-08-26 2006-09-06 松下電器産業株式会社 Mounting device for weight measuring device
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JP4152403B2 (en) 2005-06-30 2008-09-17 本田技研工業株式会社 Seat weight sensor
JP2013170994A (en) * 2012-02-22 2013-09-02 Nissan Motor Co Ltd Magnetostrictive ring type torque sensor, and method of manufacturing magnetostrictive ring type torque sensor
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