JP4270494B2

JP4270494B2 - Driving mechanism of moving body

Info

Publication number: JP4270494B2
Application number: JP2003135974A
Authority: JP
Inventors: 文雄土岡; 貞章高木
Original assignee: Unitac Co Ltd
Current assignee: Unitac Co Ltd
Priority date: 2003-05-14
Filing date: 2003-05-14
Publication date: 2009-06-03
Anticipated expiration: 2023-05-14
Also published as: JP2004340212A

Description

【０００１】
【発明の属する技術分野】
本発明は移動体の駆動機構に関し、詳しくは、ガイドの案内によって直進方向に移動体を移動させるための駆動機構に関する。
【０００２】
【従来の技術】
これらの駆動機構として、移動体に固定した雌螺子に螺合させた雄螺子を回転させることにより移動体を移動させる如く構成したものが種々提案されている（例えば、特許文献１乃至特許文献３参照）。
【０００３】
上記特許文献１に記載された発明は位置決め装置に関するもので、モータと、このモータを制御する制御部と、モータにより回転する雄螺子と、レールにスライド移動可能に嵌合させた被載置体を載せる載置台と、この載置台に取り付けられ、雄螺子に螺合する雌螺子とを備えており、駆動機構として、上記雄螺子を回動させることにより螺合する雌螺子部分を移動させ、以て載置台を移動させる如く構成している。
【０００４】
また、上記特許文献２に記載された発明はマイクロマニピュレータに関するもので、このマイクロマニピュレータは、直進方向に移動自在な移動体と、この移動体に取り付けられた圧電・電歪素子と、この圧電・電歪素子の先端部に取り付けられたマイクロマニピュレータ用微小器具とを備え、また、駆動機構としてボール螺子を用いた機構を採用している。
【０００５】
更に上記特許文献３に記載された発明はテーブルの位置決め機構に関するもので、この位置決め装置は、ガイドレール上に第１の移動部材及び第２の移動部材を移動可能に設け、これら第１移動部材及び第２移動部材に、一対の支持腕の一端部を回動自在に取り付けるとともに、他端部に於いてテーブルを回動自在に支持する構成とし、第１移動部材及び第２移動部材をガイドレール上に於いて移動させることで支持腕を連動変位させ、ガイドレールの軸方向及び軸方向に直行する方向にテーブルの支持位置を移動調節する如く構成している。ここに於ける各移動部材の駆動機構として、ガイドレールと同軸方向に螺子シャフトを配設し、各螺子シャフトを移動部材に固定した雌螺子に螺合させて移動可能に構成している。
【０００６】
【特許文献１】
特開２００３−９０８９１号公報（第２−３頁，図２）
【特許文献２】
特開２００３−１５７４号公報（第２−３頁，図２）
【特許文献３】
特開平６−２９４７１１号公報（第２−３頁，図１）
【０００７】
【発明が解決しようとする課題】
上記した従来のこの種の駆動機構は、例えば特許文献１及び特許文献３に記載された如く移動体に雌螺子を有する雌螺子部材を固定して雄螺子としての螺子シャフトを単純に螺合させている。この様な構造では雌螺子の移動方向とガイドの案内方向とに微細な誤差が生じた場合に移動体の進退に少なからぬ影響があり、甚だしい場合には部分的に移動不能となる不都合が生じる場合がある。その原因として、例えば、螺子シャフトを移動する雌螺子の移動方向とガイド機構の移動方向の並行性に成形上の誤差が生じる等が挙げられる。従来は成形精度を上げる等によりこれらの不都合に対処しているが、その製造上の煩雑さ、コスト等に問題が生じる。
【０００８】
この様な状況に対応するために特許文献２に記載された如きボール螺子を用いた駆動機構を採用することが行われている。このボール螺子は、従来の雌螺子に代えて、雄螺子の螺子山間に一部を嵌合させた多数のボールを、螺旋状に且つ回動可能に多数配置した雌螺子部材を備え、この多数の螺旋状ボール群の存在により雌螺子部材に直進方向以外の微細な変位を可能な状況を与えるものであり、上記不都合を解消できるものである。
【０００９】
しかしながら、この様な構造ではボールの大きさに対応させた螺子のピッチを必要とするため螺子のピッチ，リードに多大な制限が加えられる不都合がある。この種の駆動機構を採用する装置には、その単位回転当たりの移動距離が小さければ小さい程好ましい微細移動の可能なものが要求されており、例えば０．２５mm／回転という微細リードを要求される場合があり、その様な場合にはボールの微小成形が比較的困難な状況を考慮すると従来のボール螺子には限界があった。
【００１０】
本発明は上記した点に鑑みてなされたもので、単位回転当たりの移動距離が極微小に行えるとともに、円滑な移動体の移動が可能であって進退が重くなったり、移動不能になったりする不都合を生じることがなく、しかも構造は特別複雑でなく容易に製造が可能な移動体の駆動機構を提案するものである。
【００１１】
【課題を解決するための手段】
第１の手段として、以下の通り構成した。即ち、移動体に固定した雌螺子と、該雌螺子に螺合させた雄螺子とを備え、雄螺子の回転により上記移動体を案内機構に従って直進方向へ移動させる駆動機構であって、上記移動体が備えた円筒状装着面内周に環状に遊嵌配置した多数のボールを介し且つ上記移動体側より延設した板バネにより支持して三次元的変位が可能に且つ軸心周囲の回転を防止して装着した筒体を設け、該筒体内周面に上記雌螺子を刻設したことを特徴とする移動体の駆動機構。
【００１２】
第２の手段として、以下の通り構成した。即ち、前記第１の手段に於いて、上記筒体が、内筒及び外筒よりなる二重筒間に上記多数のボールを環状に遊嵌配置した筒部材の内筒であり、上記装着面が、ブラケットを介して移動体に固定した上記外筒の内周面である。
【００１３】
第３の手段として、以下の通り構成した。即ち、前記第１の手段に於いて、上記筒体が、ボールベアリングの内筒と、該内筒内面に嵌合するとともに、内周面に上記雌螺子を刻設した雌螺子筒とで構成した筒体であり、上記装着面が、ブラケットを介して移動体に固定したボールベアリングの外筒内周面である。
【００１４】
第４の手段として、以下の通り構成した。即ち、前記第１の手段乃至第３の手段のいずれかの手段に於いて、上記雌螺子と雄螺子とのリードが０．１ｍｍ／回転〜０．５ｍｍ／回転である。
【００１５】
第５の手段として、以下の通り構成した。即ち、前記第１の手段乃至第３の手段のいずれかの手段に於いて、上記板バネが、上記筒体端面側方の上記移動体側に基端部を固定した並行する一対のアーチ状をなすとともに、各先端部を上記筒体端面の対向位置に嵌着固定した板バネである。
【００１６】
【発明の実施の形態】
以下、本発明の実施例の形態を図面を参照して説明する。
【００１７】
図１は本発明駆動機構を備えた位置決め装置の一例を示す概略図であり、本発明の移動体の駆動機構は、図示例の如く、移動体２を案内機構３に従って直進方向へ移動させるためのものであり、移動体２に固定した雌螺子４と、該雌螺子４に螺合させた雄螺子５とを備え、雄螺子５の回転により移動体２の上記移動を行うものである。
【００１８】
移動体２の形態は種々のものが採用でき、観察用の載置物を載置するための載置台を備えたもの、或いはマイクロマニピュレータ用微小器具を備えたものなど、特に限定はない。但し、螺子のリードが例えば０．１mm／回転〜０．５mm／回転というような単位回転当たりの進行幅の極めて小さい移動に好適に使用できる。
【００１９】
また、移動体２を誘導する案内機構も種々の形態のものを採用でき、例えば、一般的なガイドレールに移動体をスライド可能に嵌合させたものや、移動体から突設した嵌合突起を凹溝にスライド可能に嵌合させることにより直進方向へ移動が可能に構成したもの等が挙げられ、その具体的形態は種々選択できる。
【００２０】
図１に於いて移動体２は支持基板６上に敷設した案内機構としてのガイドレール3aに下面部をスライド可能に嵌合させた移動基板７を有し、この移動基板７上に載置台８を固定する。雌螺子４は移動基板７の下面より垂設したブラケット９内に設けている。また、雄螺子５は上記ガイドレール3aと並行に設けられたシャフト10外周に刻設されたもので、このシャフト10をモーター11で回転させることにより螺合する雌螺子４が移動し、ひいては移動体２が移動する如く構成している。具体的には、支持基板６前縁より立設した支持壁12に回動可能に軸支したシャフト10を上記ガイドレール3aと並行に後方へ突設し、その外周の雄螺子５を上記雌螺子４と螺合させている。シャフト10の一端は支持基板６上に固定したモーター11とベルト13を介して連動させている。
【００２１】
本発明では、上記雌螺子４を筒体14の内周面に刻設している。この筒体14は、上記移動体２に備えた円筒状装着面ａ内周に環状に遊嵌配置した多数のボール15を介し且つ上記移動体側より延設した板バネ16により支持して三次元変位が可能に且つ軸心周囲の回転を防止して装着している。上記円筒状装着面ａは、上記移動体２に一体に形成しても良く、或いは円筒状装着面を備えた別部材を移動体に固定しても良い。
【００２２】
上記装着面ａへの筒体14の装着形態として具体的な一例を挙げれば、図２に示す如く、円筒状装着面ａに断面円弧状をなす第１凹溝17を周設するとともに、円筒状の筒体14の外周面に断面円弧状をなす第２凹溝18を周設し、第１凹溝17及び第２凹溝18を対向させてその両溝間に多数のボール15を隙間をもって環状に遊嵌配置することにより装着している。
【００２３】
上記各ボール15は、図３(a)に示す如き軸心であるｘ軸に対するｙ軸及びｚ軸方向の変位を補正するラジアル隙間δ_R［図２(a) ］と、ｘ軸の誤差及び図３(b) に示す如きθｙ軸（ピッチ角）とθｚ軸（ヨー角）の変位を補正するアキシャル隙間δ_A1，δ_A2［図２(b) ，(c) ］とを備えており、ラジアル隙間とアキシャル隙間とで装着面ａと筒体14とに発生する変位（雄螺子の一回転内での回転角に対する雌螺子の軸方向の進め量の差）を吸収し、ひいては雄螺子５と移動体２とに発生する変位を吸収する。
【００２４】
また、上記板バネ16は、上記各ボールに起因する上記装着面ａに対する筒体14の三次元的変位を許容し、且つ、軸心周囲の回転を阻止するものであり、その形態は種々採用できる。具体的一例として、筒体14端面側方の移動体に基端部を固定した並行する一対のアーチ状をなすとともに、各先端部を上記筒体端面の対向位置に嵌着固定したものが挙げられる。
【００２５】
図４はこの位置決め装置に採用される駆動機構の一例を示し、本実施例では、上記筒体14が、ボールベアリングＡの内筒20と、該内筒20内面に嵌合するとともに、内周面に上記雌螺子４を刻設した雌螺子筒21とで構成した筒体14であり、上記装着面ａが、ブラケット９を介して上記移動体２に固定したボールベアリングＡの外筒22内周面として構成している。
【００２６】
更に具体的には、このボールベアリングＡは内筒20の外周に上記した如き多数のボール15を介して外筒22を嵌合したものが使用でき、図示例では外筒22外周一端部より外方へフランジ23を突設している。また、雌螺子筒21は先端部外周にフランジ状突部24を突設しており、この突部24をボールベアリング内筒20端面に当接係止させて嵌着している。更に、上記内筒20より突出した部分の雌螺子筒21外周にはナット25を螺着させている。また、この雌螺子筒21を装着したボールベアリングＡを移動体２とは別体のブラケット９の貫通孔に、外筒22のフランジ23をその端面に当接係止させて嵌合している。また、ブラケット９の一端面側にはリング板状の押え部材26をボルト27で固定して上記フランジ23をブラケット９との間に挟持固定している。また、上記ボルト27により押え部材26の表面に基端部28を固定したバネ部材29を設けている。このバネ部材29は、基端部28より一対の円弧板状をなす上記板バネ16を延設し、各板バネ16の先端部を筒体14の端面（具体的には雌螺子筒21の端面）上下に凹設した嵌合溝内にそれぞれ嵌着固定しいる。
【００２７】
図６は図１の位置決め装置に採用される駆動機構の他の一例を示すものであり、上記装着面ａは、移動体２の移動基板７下面より垂設したブラケット９を貫通して形成されている。また、筒体14は円弧状装着面ａの径より所定幅小さい円筒状をなしており、その内周面に雌螺子４を刻設している。また、上記実施例と同様のバネ部材29により支持されるとともに、上記図２で説明した如き構成を介して装着面ａに嵌合させている。上記バネ部材29は、ブラケット９の端面に基端部28をボルト27により固定し、この基端部より延設した一対の円弧板状をなす板バネ16の先端部を筒体14の端面上下にそれぞれ同様に嵌着固定している。
【００２８】
図７は図１の位置決め装置に採用される駆動機構の更に他の一例を示すものであり、上記装着面ａ及び雌螺子４を、ブラケット９を介して移動体に固定した二重筒状の筒部材Ｂに形成した例を示すもので、上記筒体14が、内筒20a 及び外筒22a よりなる二重筒間に上記多数のボール15を環状に遊嵌配置した筒部材Ｂの内筒20a であり、上記装着面ａが、ブラケット９を介して移動体２に固定した上記外筒22a の内周面である如く構成している。
【００２９】
具体的には、筒部材Ｂは、円筒状の内筒20a と円筒状の外筒22a との間に上記多数のボール15を環状に遊嵌配置しており、外筒22a の外周先端より外方へフランジ23a を突設している。そして、筒体14である内筒20a の内周面に上記雌螺子４を刻設している。また、この筒部材Ｂをブラケット９の貫通孔内に嵌合し、上記図４の実施例と同様に押え部材26により挟持固定している。更に、上記実施例と同様形態のバネ部材29を、その板バネ16の先端が内筒20a 端面の上下に同様に嵌着固定している。
【００３０】
上記の如く構成した位置決め装置は、制御装置からの信号で作動するモーター11の回転をベルト13を介してシャフト10伝達し、このシャフト10の回転により螺合している雌螺子４が可動してガイドレール3aに沿って移動体２が移動する。この際ガイドレール3aと移動基板７下面との嵌合による移動体２の進行方向と、シャフト10軸心との並行性に微細なズレが生じても、筒体14が装着面ａと相対的に適正方向に傾き或いは変位し、円滑な螺動運動が進行する。
【００３１】
【発明の効果】
以上説明した如く本発明の駆動機構は、既述構成としたことにより、円滑な移動体の移動が可能であって、進退が重くなったり移動不能となったりする不都合を生じることがなく、しかも、回転単位当たりの移動距離が極めて微小に行えるものである。
【００３２】
また、第２の手段では、上記効果に加えて組み付け操作が容器である利点を兼ね備えている。
【００３３】
また、第３の手段では、上記効果に加えて既存のボールベアリングを使用できるため、ボール嵌合部分の複雑な組み付けを省略することかでき、製造時間の短縮等を図れるものである。
【００３４】
また、第４の手段では、従来この種の駆動機構では不可能であった領域の微小進退動が可能である。
【００３５】
また、第５の手段では、板バネの構造が簡単で、その装着も容易に行える利点を兼ね備えている。
【図面の簡単な説明】
【図１】本発明の駆動機構を備えた移動装置の一例を示す概略図である。
【図２】本発明の装着表面と筒材との連繋を説明する説明図である。
【図３】本発明に於ける作用を説明するための説明補助図である。
【図４】本発明の駆動機構の一例を示す横断面図である。
【図５】同実施例の板バネ部分からの正面図である。
【図６】本発明の駆動機構の他の一例を示す横断面図である。
【図７】本発明の駆動機構の更に他の一例を示す横断面図である。
【符号の説明】
２…移動体，３…案内機構，3a…ガイドレール，４…雌螺子，５…雄螺子，
６…支持基板，７…移動基板，８…載置台，９…ブラケット，10…シャフト，
11…モーター，12…支持壁，13…ベルト，14…筒体，15…ボール，
16…板バネ，17…第１凹溝，18…第２凹溝，20，20a …内筒，21…雌螺子筒，
22，22a …外筒，23…フランジ，24…フランジ状突部，25…ナット，
26…押え部材，27…ボルト，28…基端部，29…バネ部材，ａ…円筒状装着面，
Ａ…ボールベアリング，Ｂ…筒部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving mechanism for a moving body, and more particularly to a driving mechanism for moving a moving body in a straight traveling direction by guiding a guide.
[0002]
[Prior art]
As these drive mechanisms, various configurations have been proposed in which the moving body is moved by rotating a male screw screwed into a female screw fixed to the moving body (for example, Patent Documents 1 to 3). reference).
[0003]
The invention described in Patent Document 1 relates to a positioning device, and includes a motor, a control unit that controls the motor, a male screw that is rotated by the motor, and a mounting body that is slidably fitted to a rail. And a female screw attached to the mounting table and screwed into the male screw, and as a drive mechanism, the female screw part to be screwed is moved by rotating the male screw, Thus, the mounting table is configured to move.
[0004]
The invention described in Patent Document 2 relates to a micromanipulator. The micromanipulator includes a movable body that is movable in a straight direction, a piezoelectric / electrostrictive element attached to the movable body, and a piezoelectric / electrostrictive element. A micromanipulator micro-tool attached to the tip of the electrostrictive element, and a mechanism using a ball screw as the drive mechanism.
[0005]
Further, the invention described in Patent Document 3 relates to a table positioning mechanism. This positioning device is provided with a first moving member and a second moving member movably provided on a guide rail, and these first moving members are provided. And one end of a pair of support arms is rotatably attached to the second moving member, and the table is rotatably supported at the other end, and the first moving member and the second moving member are guided. By moving on the rail, the support arm is displaced in an interlocking manner, and the support position of the table is moved and adjusted in the axial direction of the guide rail and the direction orthogonal to the axial direction. As a driving mechanism of each moving member here, a screw shaft is arranged in the same direction as the guide rail, and each screw shaft is screwed into a female screw fixed to the moving member so as to be movable.
[0006]
[Patent Document 1]
JP 2003-90891 A (page 2-3, FIG. 2)
[Patent Document 2]
JP 2003-1574 A (page 2-3, FIG. 2)
[Patent Document 3]
JP-A-6-294711 (page 2-3, FIG. 1)
[0007]
[Problems to be solved by the invention]
In the conventional drive mechanism of the above-described type, for example, as described in Patent Document 1 and Patent Document 3, a female screw member having a female screw is fixed to a moving body, and a screw shaft as a male screw is simply screwed together. ing. In such a structure, if a minute error occurs between the moving direction of the female screw and the guiding direction of the guide, there is a considerable influence on the advancement and retraction of the moving body, and in a severe case, there is a disadvantage that the moving part is partially unmovable. There is a case. As the cause, for example, an error in molding occurs in the parallelism of the moving direction of the female screw that moves the screw shaft and the moving direction of the guide mechanism. Conventionally, these inconveniences have been dealt with by increasing molding accuracy, but there are problems in the complexity and cost of manufacturing.
[0008]
In order to cope with such a situation, a drive mechanism using a ball screw as described in Patent Document 2 is employed. This ball screw is provided with a female screw member in which a large number of balls, each of which is partially fitted between screw threads of a male screw, are arranged in a spiral and rotatable manner instead of the conventional female screw. The presence of the spiral ball group gives the female screw member a situation in which a fine displacement other than the straight traveling direction is possible, and the above inconvenience can be solved.
[0009]
However, such a structure requires a pitch of the screw corresponding to the size of the ball, and thus has a disadvantage that a great restriction is imposed on the pitch and lead of the screw. An apparatus that employs this type of driving mechanism is required to have a fine movement that is preferable as the movement distance per unit rotation is smaller. For example, a fine lead of 0.25 mm / rotation is required. In such a case, the conventional ball screw has a limit in consideration of a situation in which it is relatively difficult to form a ball.
[0010]
The present invention has been made in view of the above points, and the moving distance per unit rotation can be made extremely small, and the moving body can be moved smoothly, making it difficult to move forward and backward. The present invention proposes a drive mechanism for a moving body that does not cause inconvenience and that can be easily manufactured without any special complexity.
[0011]
[Means for Solving the Problems]
The first means is configured as follows. That is, a drive mechanism that includes a female screw fixed to a moving body and a male screw screwed into the female screw, and that moves the moving body in a straight direction according to a guide mechanism by the rotation of the male screw. It is supported by a plate spring extended from the movable body side via a large number of balls that are loosely arranged annularly on the inner periphery of the cylindrical mounting surface provided in the body, and can be displaced three-dimensionally and can rotate around the axis. preventing provided with a cylindrical body mounted, driving Organization of the moving body, characterized in that engraved the female thread in the cylindrical body periphery.
[0012]
The second means is configured as follows. That is, in the first means, the cylindrical body is an inner cylinder of a cylindrical member in which the plurality of balls are loosely arranged in an annular manner between double cylinders composed of an inner cylinder and an outer cylinder, and the mounting surface but Ru inner periphery der of fixed the outer tube to the mobile via the bracket.
[0013]
The third means was configured as follows. That is, in the first means, the cylindrical body is constituted by an inner cylinder of a ball bearing and a female screw cylinder that is fitted to the inner surface of the inner cylinder and in which the female screw is engraved on the inner peripheral surface. The mounting surface is the inner peripheral surface of the outer cylinder of the ball bearing fixed to the moving body via the bracket.
[0014]
The fourth means is configured as follows. That is, at any means of said first means to the third means, the lead of the female screw and the male screw is Ru 0.1 mm / rotation to 0.5 mm / rotation der.
[0015]
The fifth means is configured as follows. That is, in any one of the first to third means, the leaf spring has a pair of parallel arch shapes in which a base end portion is fixed to the movable body side on the side of the cylindrical body end face. with eggplant, Ru Oh each tip of a plate spring which is fitted and fixed to the opposing position of the cylinder end face.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a schematic view showing an example of a positioning device provided with a drive mechanism of the present invention. The drive mechanism of a moving body of the present invention moves a moving body 2 in a straight direction according to a guide mechanism 3 as shown in the drawing. This includes a female screw 4 fixed to the moving body 2 and a male screw 5 screwed to the female screw 4, and the moving body 2 is moved by the rotation of the male screw 5.
[0018]
Various forms of the moving body 2 can be adopted, and there are no particular limitations such as those provided with a mounting table for mounting an observation mounting object or those equipped with a micromanipulator micro instrument. However, the lead of the screw can be suitably used for movement with a very small travel width per unit rotation such as 0.1 mm / rotation to 0.5 mm / rotation.
[0019]
Also, various types of guide mechanisms for guiding the mobile body 2 can be employed, for example, a general guide rail that is slidably fitted to the guide body, or a fitting protrusion that protrudes from the mobile body And the like can be slidably fitted in the concave groove so as to be movable in the straight direction, and the specific form thereof can be variously selected.
[0020]
In FIG. 1, the moving body 2 has a moving substrate 7 in which a lower surface portion is slidably fitted to a guide rail 3 a as a guide mechanism laid on a supporting substrate 6, and a mounting table 8 is placed on the moving substrate 7. To fix. The female screw 4 is provided in a bracket 9 that is suspended from the lower surface of the moving substrate 7. The male screw 5 is engraved on the outer periphery of the shaft 10 provided in parallel with the guide rail 3a. When the shaft 10 is rotated by the motor 11, the female screw 4 to be screwed moves, and thus moves. The body 2 is configured to move. Specifically, a shaft 10 pivotally supported on a support wall 12 erected from the front edge of the support substrate 6 is protruded rearward in parallel with the guide rail 3a, and the male screw 5 on the outer periphery thereof is connected to the female screw. Screwed into the screw 4. One end of the shaft 10 is interlocked with a motor 11 fixed on the support substrate 6 via a belt 13.
[0021]
In the present invention, the female screw 4 is engraved on the inner peripheral surface of the cylindrical body 14. The cylindrical body 14 is supported by a plate spring 16 extending from the movable body side through a large number of balls 15 that are loosely arranged in an annular shape on the inner circumference of the cylindrical mounting surface a provided in the movable body 2 and is three-dimensionally supported. Mounted so that displacement is possible and rotation around the axis is prevented. The cylindrical mounting surface a may be formed integrally with the moving body 2 or another member having the cylindrical mounting surface may be fixed to the moving body.
[0022]
As a specific example of the mounting form of the cylindrical body 14 on the mounting surface a, as shown in FIG. 2, the cylindrical mounting surface a is provided with a first concave groove 17 having a circular arc cross section, and a cylindrical shape. A second concave groove 18 having an arc shape in cross section is provided on the outer peripheral surface of the cylindrical tube 14, and the first concave groove 17 and the second concave groove 18 are opposed to each other, and a large number of balls 15 are formed between the two grooves. It is mounted by placing it in a ring.
[0023]
Each of the balls 15 has a radial gap δ _R [FIG. 2 (a)] that corrects displacement in the y-axis and z-axis directions with respect to the x-axis, which is the axis as shown in FIG. As shown in FIG. 3 (b), the axial gaps δ _A1 and δ _A2 [FIGS. 2 (b) and (c)] for correcting the displacement of the θy axis (pitch angle) and the θz axis (yaw angle) are provided. The radial gap and the axial gap absorb the displacement (difference in the amount of advance of the female screw in the axial direction with respect to the rotation angle within one rotation of the male screw) generated on the mounting surface a and the cylindrical body 14, and consequently the male screw 5 And the displacement generated in the moving body 2 is absorbed.
[0024]
Further, the leaf spring 16 allows three-dimensional displacement of the cylindrical body 14 with respect to the mounting surface a caused by the balls and prevents rotation around the axis, and various forms thereof are adopted. it can. As a specific example, there is a pair of parallel arches in which a base end is fixed to a moving body on the side of the end face of the cylinder 14, and each tip is fitted and fixed at a position opposite to the end face of the cylinder. It is done.
[0025]
FIG. 4 shows an example of a drive mechanism employed in this positioning device. In this embodiment, the cylinder 14 is fitted to the inner cylinder 20 of the ball bearing A and the inner surface of the inner cylinder 20, and the inner circumference A cylindrical body 14 composed of a female screw cylinder 21 having the female screw 4 engraved on its surface, and the mounting surface a is inside the outer cylinder 22 of the ball bearing A fixed to the movable body 2 via a bracket 9. It is configured as a peripheral surface.
[0026]
More specifically, the ball bearing A can be used in which the outer cylinder 22 is fitted to the outer periphery of the inner cylinder 20 via the numerous balls 15 as described above. A flange 23 protrudes in the direction. Further, the female screw cylinder 21 has a flange-like protrusion 24 projecting from the outer periphery of the tip, and this protrusion 24 is abutted and locked to the end face of the ball bearing inner cylinder 20. Further, a nut 25 is screwed onto the outer periphery of the female screw cylinder 21 at a portion protruding from the inner cylinder 20. Further, the ball bearing A fitted with the female screw cylinder 21 is fitted into the through hole of the bracket 9 separate from the moving body 2 by abutting and locking the flange 23 of the outer cylinder 22 to the end face thereof. . A ring plate-like pressing member 26 is fixed to one end surface side of the bracket 9 with a bolt 27, and the flange 23 is sandwiched and fixed between the bracket 9 and the bracket 9. Further, a spring member 29 having a base end portion 28 fixed to the surface of the pressing member 26 by the bolt 27 is provided. The spring member 29 extends from the base end portion 28 with a pair of arc plate-like plate springs 16, and the distal end portion of each plate spring 16 is connected to the end surface of the cylinder body 14 (specifically, the female screw cylinder 21. End surfaces are fixedly fitted in fitting grooves recessed vertically.
[0027]
FIG. 6 shows another example of the drive mechanism employed in the positioning device of FIG. 1, and the mounting surface a is formed through a bracket 9 that is suspended from the lower surface of the moving substrate 7 of the moving body 2. ing. The cylindrical body 14 has a cylindrical shape having a predetermined width smaller than the diameter of the arcuate mounting surface a, and the female screw 4 is engraved on the inner peripheral surface thereof. Further, it is supported by a spring member 29 similar to that in the above embodiment, and is fitted to the mounting surface a through the configuration described in FIG. The spring member 29 has a base end portion 28 fixed to the end face of the bracket 9 with a bolt 27, and a tip end portion of a pair of circular plate springs 16 extending from the base end portion is connected to the upper and lower ends of the cylinder body 14. Are fixed in the same manner.
[0028]
FIG. 7 shows still another example of the drive mechanism employed in the positioning device of FIG. 1, and is a double cylindrical shape in which the mounting surface a and the female screw 4 are fixed to a moving body via a bracket 9. An example in which the cylindrical member B is formed in the cylindrical member B is an inner cylinder of the cylindrical member B in which the plurality of balls 15 are loosely and annularly arranged between the double cylinders including the inner cylinder 20a and the outer cylinder 22a. 20a, and the mounting surface a is configured to be the inner peripheral surface of the outer cylinder 22a fixed to the moving body 2 via the bracket 9.
[0029]
Specifically, the cylindrical member B has a large number of the balls 15 that are loosely fitted in an annular shape between a cylindrical inner cylinder 20a and a cylindrical outer cylinder 22a. A flange 23a is projected in the direction. The female screw 4 is engraved on the inner peripheral surface of the inner cylinder 20a which is the cylinder body 14. Further, the cylindrical member B is fitted into the through hole of the bracket 9 and is clamped and fixed by the pressing member 26 as in the embodiment of FIG. Further, the spring member 29 having the same form as in the above-described embodiment is similarly fitted and fixed to the top and bottom of the end surface of the inner cylinder 20a at the tip of the leaf spring 16.
[0030]
The positioning device configured as described above transmits the rotation of the motor 11 operated by a signal from the control device via the belt 13 to the shaft 10, and the female screw 4 screwed by the rotation of the shaft 10 moves. The moving body 2 moves along the guide rail 3a. At this time, even if a slight deviation occurs in the parallelism between the traveling direction of the moving body 2 due to the fitting of the guide rail 3a and the lower surface of the moving substrate 7 and the axis of the shaft 10, the cylindrical body 14 is relative to the mounting surface a. Inclined or displaced in an appropriate direction, and a smooth screw motion proceeds.
[0031]
【The invention's effect】
As described above, the drive mechanism of the present invention is configured as described above, so that the moving body can be moved smoothly, and there is no inconvenience that the advancement / retraction becomes heavy or the movement becomes impossible. The moving distance per rotation unit can be made extremely small.
[0032]
Further, the second means has the advantage that the assembling operation is a container in addition to the above effects.
[0033]
In addition, in the third means, in addition to the above effects, an existing ball bearing can be used, so that complicated assembly of the ball fitting portion can be omitted, and the manufacturing time can be shortened.
[0034]
In addition, the fourth means allows a minute advance / retreat of a region that has been impossible with this type of drive mechanism.
[0035]
Further, the fifth means has the advantage that the structure of the leaf spring is simple and can be easily mounted.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a moving device provided with a drive mechanism of the present invention.
FIG. 2 is an explanatory view for explaining the connection between the mounting surface and the tubular member of the present invention.
FIG. 3 is an explanatory auxiliary diagram for explaining the operation in the present invention.
FIG. 4 is a transverse sectional view showing an example of a drive mechanism of the present invention.
FIG. 5 is a front view from the leaf spring portion of the embodiment.
FIG. 6 is a cross-sectional view showing another example of the drive mechanism of the present invention.
FIG. 7 is a cross-sectional view showing still another example of the drive mechanism of the present invention.
[Explanation of symbols]
2 ... moving body, 3 ... guide mechanism, 3a ... guide rail, 4 ... female screw, 5 ... male screw,
6 ... support substrate, 7 ... moving substrate, 8 ... mounting table, 9 ... bracket, 10 ... shaft,
11 ... motor, 12 ... support wall, 13 ... belt, 14 ... cylinder, 15 ... ball,
16 ... leaf spring, 17 ... first groove, 18 ... second groove, 20, 20a ... inner tube, 21 ... female screw tube,
22, 22a ... outer cylinder, 23 ... flange, 24 ... flange-like projection, 25 ... nut,
26 ... Presser member, 27 ... Bolt, 28 ... Base end, 29 ... Spring member, a ... Cylindrical mounting surface,
A ... Ball bearing, B ... Cylinder member

Claims

A drive mechanism comprising a female screw fixed to a moving body and a male screw screwed into the female screw, wherein the moving body moves in the straight direction according to a guide mechanism by the rotation of the male screw. It is supported by a leaf spring extended from the movable body side through a large number of balls that are loosely arranged annularly on the inner periphery of the cylindrical mounting surface provided, and can be displaced three-dimensionally and prevents rotation around the axis. And the female screw is engraved on the peripheral surface of the cylindrical body, and the cylindrical body loosely fits the plurality of balls in a circular manner between the double cylinders composed of the inner cylinder and the outer cylinder. A driving mechanism for a moving body, wherein the moving body is an inner cylinder of the arranged cylindrical member, and the mounting surface is an inner peripheral surface of the outer cylinder fixed to the moving body via a bracket.

A drive mechanism comprising a female screw fixed to a moving body and a male screw screwed into the female screw, wherein the moving body moves in the straight direction according to a guide mechanism by the rotation of the male screw. It is supported by a leaf spring extended from the movable body side through a large number of balls that are loosely arranged annularly on the inner periphery of the cylindrical mounting surface provided, and can be displaced three-dimensionally and prevents rotation around the axis. The internal thread is provided on the peripheral surface of the cylindrical body, and the cylindrical body is fitted to the inner cylinder of the ball bearing and the inner surface of the inner cylinder. A moving body comprising: a female screw cylinder in which the female screw is engraved, wherein the mounting surface is an inner peripheral surface of an outer cylinder of a ball bearing fixed to the moving body via a bracket. Drive mechanism.

The moving body drive mechanism according to claim 1, wherein the lead of the female screw and the male screw is 0.1 mm / rotation to 0.5 mm / rotation.

The leaf spring has a pair of parallel arches in which the base end portion is fixed to the movable body side on the side of the cylindrical body end surface, and each distal end portion is fitted and fixed at a position opposite to the cylindrical body end surface. The driving mechanism for a moving body according to claim 1, wherein the driving mechanism is a moving body.