JP5856945B2

JP5856945B2 - Tool chuck device

Info

Publication number: JP5856945B2
Application number: JP2012269316A
Authority: JP
Inventors: 田中　仁; 仁田中
Original assignee: J Morita Manufaturing Corp
Current assignee: J Morita Manufaturing Corp
Priority date: 2012-12-10
Filing date: 2012-12-10
Publication date: 2016-02-10
Anticipated expiration: 2032-12-10
Also published as: JP2014113301A

Description

本発明は、工具チャック装置に関し、具体的には、医科歯科用ハンドピースの先端ヘッド部に設けられ、歯牙等の患部の切削等に用いられる切削回転工具を着脱自在に装着し得る工具チャック装置の改良に関するものである。 TECHNICAL FIELD The present invention relates to a tool chuck device, and more specifically, a tool chuck device that is provided at a distal end head portion of a medical / dental handpiece and can be detachably mounted with a cutting rotary tool used for cutting an affected part such as a tooth. It is about improvement.

前記のような医科歯科用ハンドピースには、その先端ヘッド部に、前記切削回転工具を着脱自在に装着し得る工具チャック装置が組み込まれている。医科歯科の診療においては、術者は、患部の状態に応じて、それに適正な切削回転工具をヘッド部に適宜交換装着して診療に用いる。そのため、切削回転工具を着脱自在に装着し得るチャック装置がヘッド部に組み込まれる。そして、このような工具チャック装置には、診療の効率化の観点から、切削回転工具の着脱操作が簡易に行え、且つ、回転中に切削回転工具が抜け出さないよう確実に切削回転工具を保持し得る機構が求められる。このような工具チャック装置の一例として、特許文献１に記載されたものを挙げることができる。 The medical and dental handpiece as described above incorporates a tool chuck device capable of detachably mounting the cutting rotary tool at the tip head portion thereof. In medical / dental practice, an operator uses an appropriate cutting and rotating tool on the head part for use in medical treatment according to the condition of the affected part. Therefore, a chuck device that can detachably mount the cutting rotary tool is incorporated in the head portion. Such a tool chuck device can easily attach and detach the cutting rotary tool from the viewpoint of improving medical efficiency, and securely holds the cutting rotary tool so that the cutting rotary tool does not come out during rotation. A mechanism to obtain is required. As an example of such a tool chuck device, one described in Patent Document 1 can be cited.

特許文献１に開示された工具チャック装置では、ヘッド部に軸回転可能に内装されるバーチューブ（工具保持部材）にコントラバー（切削回転工具）が挿通可能とされ、該バーチユーブの基端部に挿通されたコントラバーを係合保持するバー係合保持部材が設けられている。このバー係合保持部材は、これ自体が拡開弾性変形する弾性リング部材からなり、押圧部材からなるコントラバー解除部材によって、前記弾性リング部材を拡開させて、コントラバーの保持を解除させるように構成されている。 In the tool chuck device disclosed in Patent Document 1, a contrabar (cutting rotary tool) can be inserted into a bar tube (tool holding member) that is rotatably mounted in the head portion, and is attached to the base end portion of the birch tube. A bar engagement holding member for engaging and holding the inserted contrabar is provided. The bar engagement holding member itself is formed of an elastic ring member that expands and deforms elastically, and the elastic ring member is expanded by a contra bar release member formed of a pressing member so that the holding of the contra bar is released. It is configured.

実開平７−７６０９号公報Japanese Utility Model Publication No. 7-7609

ところで、特許文献１に開示された工具チャック装置の場合、開環状の弾性リング部材からなるバー係合保持部材は、コントラバーの基端部に形成された周溝にコントラバーを抱持するよう嵌り込んで、コントラバーが抜け落ちないように係合保持するものである。そのため、この弾性リング部材による係合保持を解除する場合、当該弾性リング部材を、コントラバーの外径より大きく、前記周溝より完全に脱出し得るように拡開する必要がある。従って、弾性リング部材の拡開に要する大きなスペースをバーチューブ更にはヘッド部内に確保する必要があり、これによって、バーチューブ更にはヘッド部の外径を大きくせざるを得ず、狭い口腔内で使用される歯科用ハンドピースの場合には、その適正が損なわれる可能性がある。一方、拡開変形量を少なくして係合保持させようとすると、係合保持量が少なくなり、それだけ回転中のコントラバーの抜け落ちの危険性が高まることにもなる。 By the way, in the case of the tool chuck device disclosed in Patent Document 1, the bar engagement holding member made of an open ring-shaped elastic ring member holds the contra bar in the circumferential groove formed in the base end portion of the contra bar. It is engaged and held so that the contrabar does not fall out. Therefore, when releasing the engagement and holding by the elastic ring member, it is necessary to expand the elastic ring member so that it is larger than the outer diameter of the contrabar and can completely escape from the circumferential groove. Therefore, it is necessary to secure a large space required for the expansion of the elastic ring member in the bur tube and further in the head portion. As a result, it is necessary to increase the outer diameter of the bur tube and further in the head portion. In the case of the dental handpiece used, its suitability may be impaired. On the other hand, if the expansion deformation amount is reduced and the engagement is held, the engagement holding amount is reduced, and the risk of falling off of the rotating contrabar is increased accordingly.

本発明は、このような実情に鑑みなされたもので、コンパクトで、且つ、切削回転工具の保持が確実になされ、切削回転工具の着脱も簡易になし得る医科歯科用ハンドピースの工具チャック装置を提供することを目的とする。 The present invention has been made in view of such circumstances, and a tool chuck device for a medical / dental handpiece that is compact, securely holds a cutting rotary tool, and can be easily attached and detached. The purpose is to provide.

本発明に係る工具チャック装置は、医科歯科用ハンドピースの先端ヘッド部に設けられ、切削回転工具を着脱自在に装着し得る工具チャック装置であって、前記先端ヘッド部に軸回転可能に内装され、前記切削回転工具を同心的に挿通し得る内筒部を備えた中空円筒状の工具保持部材と、前記工具保持部材の基端部側の胴部に内外に連通するよう形成された開口部に、前記内筒部に一部が臨んで、挿通された前記切削回転工具の基端部を係止するよう、該工具保持部材の軸心に直交する方向にスライド自在に支持される係止用爪部材と、前記係止用爪部材を前記工具保持部材の軸心側に弾力付勢する係止用弾性部材と、前記係止用爪部材を前記係止用弾性部材の付勢力に抗して前記工具保持部材の遠心側に変位させて前記切削回転工具に対する係止を解除させる係止解除部材と、を備え、前記工具保持部材における前記係止用爪部材の支持部には、遠心方向に張出す平坦面を備えたフランジ部が形成され、前記係止用爪部材は当該フランジ部の平坦面に沿ってスライド可能に支持されており、前記フランジ部の平坦面上には、前記係止用爪部材と前記工具保持部材との前記軸心回りの相対回転を不能とする規制手段として、前記係止用爪部材の前記軸心の回りの両端部に当接するよう形成された２個の突起が設けられており、前記係止用爪部材の外周部には、周溝と周溝を分断する区画壁部とが形成され、前記係止用弾性部材は、前記周溝に嵌め入れられ、かつ開環端部が前記区画壁部を隔てて互いに対峙するように位置付けられる開環リング状に形成され、前記工具保持部材の周面には、前記係止用弾性部材に求心方向に向くように形成された屈曲部が嵌り込む凹所が形成されていることを特徴とする。 A tool chuck device according to the present invention is a tool chuck device which is provided at a distal end head portion of a medical / dental handpiece and can detachably mount a cutting rotary tool, and is internally mounted on the distal end head portion so as to be capable of rotating an axis. A hollow cylindrical tool holding member having an inner cylindrical portion through which the cutting rotary tool can be inserted concentrically, and an opening formed to communicate with the body on the base end side of the tool holding member In addition, the latch is supported so as to be slidable in a direction perpendicular to the axis of the tool holding member so that a part thereof faces the inner cylinder portion and the proximal end portion of the inserted cutting rotary tool is locked. A locking claw member, a locking elastic member that elastically biases the locking claw member toward the axial center of the tool holding member, and the locking claw member that resists the biasing force of the locking elastic member. Then, it is displaced to the centrifugal side of the tool holding member to face the cutting rotary tool. A locking release member for releasing the locking, and a support portion of the locking claw member in the tool holding member is formed with a flange portion having a flat surface extending in a centrifugal direction, and the locking The claw member is supported so as to be slidable along the flat surface of the flange portion, and the locking claw member and the tool holding member are disposed on the flat surface of the flange portion. As the restricting means that disables rotation, two protrusions formed so as to come into contact with both end portions around the axis of the locking claw member are provided, and an outer peripheral portion of the locking claw member Are formed with a circumferential groove and a partition wall portion that divides the circumferential groove, the locking elastic member is fitted into the circumferential groove, and the ring-opening end faces the partition wall portion to face each other. Formed in the shape of an open ring that is positioned to To is characterized in that the recess bend formed to face the centripetal direction in the elastic member for the engagement is fitted is formed.

また、本発明の工具チャック装置において、前記先端ヘッド部はヘッドハウジングを備え、前記工具保持部材は、当該ヘッドハウジングに、前記係止用爪部材の支持部より先側部分に設けられる軸受を介して軸回転可能に内装されているものとしても良い。この場合、前記軸受は、前記工具保持部材の長手方向に沿って２個設けられ、前記ヘッドハウジングは、前記基端部側に相当する部分に開口部を有し、前記２個の軸受は、当該開口部側から前記ヘッドハウジング内に前記先側部分に向け組み付けられているものとしても良い。更に、前記係止解除部材は、前記ヘッドハウジングの開口部に、工具保持部材の軸心方向に沿って変位可能且つ当該開口部を塞ぐように設けられるプッシュキャップと、該プッシュキャップを前記軸心方向に沿ってヘッドハウジングの外側に向け付勢する解除用弾性部材とを含み、前記プッシュキャップは、その内面に筒状の作用突部を備え、前記解除用弾性部材の付勢力に抗して押圧操作された際、前記作用突部が前記係止用爪部材に作用して、当該係止用爪部材を前記係止用弾性部材の付勢力に抗して遠心側に変位させるよう構成されているものとしても良い。そして、前記解除用弾性部材が、金属性の板状ばね部材を打抜き加工した環状体からなり、当該環状体の外径部の形状が円形で且つ内径部の形状が前記作用突部を遊挿し得る楕円形であり、該楕円形の短径を正中として湾曲形成されたものであっても良い。 In the tool chuck device of the present invention, the tip head portion includes a head housing, and the tool holding member is provided on the head housing via a bearing provided at a portion on the front side of the support portion of the locking claw member. It is good also as what is equipped so that shaft rotation is possible. In this case, two bearings are provided along the longitudinal direction of the tool holding member, the head housing has an opening in a portion corresponding to the base end side, and the two bearings are It is good also as what is assembled | attached toward the said front side part in the said head housing from the said opening part side. Further, the locking release member includes a push cap provided at the opening of the head housing so as to be displaceable along the axial direction of the tool holding member and to close the opening, and the push cap is attached to the axial center. An elastic member for release that urges the head housing toward the outside of the head housing along the direction, and the push cap has a cylindrical action protrusion on its inner surface, and resists the urging force of the elastic member for release. When the pressing operation is performed, the operating protrusion acts on the locking claw member, and the locking claw member is displaced to the centrifugal side against the urging force of the locking elastic member. It may be good. The release elastic member is formed of an annular body obtained by punching a metal plate spring member, and the outer diameter portion of the annular body is circular and the shape of the inner diameter portion loosely inserts the action protrusion. It may be an elliptical shape that is obtained and curved with the minor axis of the elliptical shape being the median.

本発明によれば、医科歯科用ハンドピースの先端ヘッド部に設けられる工具チャック装置に切削回転工具を装着することによって、当該医科歯科用ハンドピースを、患部の医科歯科診療に用いることができる。そして、前記切削回転工具は、前記先端ヘッド部に軸回転可能に内装される工具保持部材に挿通され、係止用爪部材によって工具保持部材に係止保持される。従って、工具保持部材の軸回転が前記切削回転工具の軸回転に伝達され、切削回転工具の軸回転によって患部の切削診療等が実施可能とされる。また、切削回転工具は工具保持部材に着脱自在に装着されるから、患部の状態に応じた切削回転工具を選択装着することによって、その適正な切削診療を実施することができる。 ADVANTAGE OF THE INVENTION According to this invention, the said medical dental handpiece can be used for the medical dentistry of an affected part by mounting | wearing the cutting rotary tool with the tool chuck apparatus provided in the front-end | tip head part of a medical / dental handpiece. Then, the cutting rotary tool is inserted into a tool holding member that is built in the tip head portion so as to be axially rotatable, and is held and held on the tool holding member by a locking claw member. Accordingly, the axial rotation of the tool holding member is transmitted to the axial rotation of the cutting rotary tool, and cutting medical treatment of the affected part can be performed by the axial rotation of the cutting rotary tool. In addition, since the cutting rotary tool is detachably attached to the tool holding member, appropriate cutting medical care can be performed by selectively attaching the cutting rotary tool according to the state of the affected part.

前記切削回転工具は、前記工具保持部材の基端部側の胴部に内外に連通するよう形成された開口部に、前記内筒部に一部が臨み、この内筒部に臨む一部によって、挿通された前記切削回転工具の基端部が係止されて工具保持部材からの抜けが防止される。該係止用爪部材は、工具保持部材の軸心に直交する方向にスライド自在に支持され、係止用弾性部材によって前記工具保持部材の軸心側に弾力付勢されるから、この弾力付勢によって、前記切削回転工具の前記係止状態が維持される。そして、係止解除部材によって、前記係止用爪部材を前記係止用弾性部材の付勢力に抗して前記工具保持部材の遠心側に変位させることによって、前記切削回転工具に対する係止を解除させ、切削回転工具を取出すことができる。係止用爪部材は、係止用弾性部材の弾力付勢を伴い、前記軸心に直交する方向にスライド自在に設けられているから、前記特許文献１に示されるよう拡開弾性変形するもののように、その変位に大きなスペースを必要としない。従って、当該係止用爪部材が工具保持部材と共に内装されるハンドピースのヘッド部の外径が大きくなる懸念がない。 The cutting rotary tool has a part facing the inner cylinder part in an opening formed to communicate with the body part on the base end part side of the tool holding member, and a part facing the inner cylinder part. The base end portion of the inserted cutting rotary tool is locked, and the removal from the tool holding member is prevented. The locking claw member is slidably supported in a direction perpendicular to the axis of the tool holding member, and is elastically biased toward the axis of the tool holding member by the locking elastic member. The locked state of the cutting rotary tool is maintained by the force. Then, the locking release member disengages the cutting rotary tool by displacing the locking claw member to the distal side of the tool holding member against the biasing force of the locking elastic member. The cutting rotary tool can be taken out. The locking claw member is provided so as to be slidable in a direction perpendicular to the axis with the elastic biasing of the locking elastic member. As such, the displacement does not require a large space. Therefore, there is no concern that the outer diameter of the head portion of the handpiece in which the locking claw member is installed together with the tool holding member will be increased.

更に、前記係止用爪部材は、その支持部に設けられた規制手段によって、前記係止用爪部材の前記軸心に直交する方向へのスライド変位は許容されながらも、前記工具保持部材との前記軸心回りの相対回転を不能とされている。これによって、回転中に不意に係止解除操作がなされても、相対回転に伴い、当該係止用爪部材がその周辺部材に対してくさびのように食い込んで戻らなくなるような不測の事態を生じる懸念がない。 Further, the locking claw member is allowed to slide with the tool holding member while being allowed to slide in a direction perpendicular to the axis of the locking claw member by a restricting means provided at a support portion thereof. The relative rotation around the axis is impossible. As a result, even if the unlocking operation is unexpectedly performed during the rotation, an unexpected situation occurs in which the locking claw member bites into the peripheral member like a wedge and does not return with the relative rotation. There is no concern.

また、前記工具保持部材における前記係止用爪部材の支持部に、遠心方向に張出す平坦面を備えたフランジ部が形成されたものとすれば、前記係止用爪部材は、当該フランジ部によって安定的に支持されると共に、当該フランジ部の平坦面に沿ったスライド変位が円滑になされる。 Moreover, if the flange part provided with the flat surface which protrudes in a centrifugal direction is formed in the support part of the said nail | claw member for a locking in the said tool holding member, the said nail | claw member for a latch will be the said flange part. Is stably supported, and the slide displacement along the flat surface of the flange portion is smoothly performed.

また、前記規制手段が、前記のように２個の突起からなるものとすれば、該突起が前記係止用爪部材の前記軸心の回りの両端部に当接することによって、係止用爪部材と工具保持部材との前記軸心回りの相対回転が確実に防止される。そして、この突起は、工具保持部材の切削加工時に、前記支持部に***するよう形成することが可能であるから、突起に相当するものを別部品として準備する必要がなく、部品点数の増加を抑えることができる。 Further, if the restricting means is composed of two protrusions as described above, the protrusions come into contact with both end portions around the axis of the locking claw member, so that the locking claw The relative rotation of the member and the tool holding member around the axis is reliably prevented. And since this protrusion can be formed so as to be raised on the support portion when cutting the tool holding member, it is not necessary to prepare a part corresponding to the protrusion as a separate part, and the number of parts can be increased. Can be suppressed.

また、前記工具保持部材が、前記ヘッドハウジングに、前記係止用爪部材の支持部より先側部分に設けられる軸受を介して軸回転可能に内装されているものとした場合、支持部と軸受とが前記軸心に直交する方向に重ならず、この部分が径大化する懸念がない。この場合、前記軸受を、前記工具保持部材の長手方向に沿って２個設けるようにすれば、工具保持部材が２個の軸受によって安定した軸回転可能状態で支持がなされる。そして、前記ヘッドハウジングは、前記基部側に相当する部分に開口部を有しているので、前記２個の軸受は、当該開口部側から前記ヘッドハウジング内に前記先側部分に向け容易に組み付けることができる。 Further, when the tool holding member is incorporated in the head housing so as to be axially rotatable through a bearing provided at a portion ahead of the support portion of the locking claw member, the support portion and the bearing And do not overlap in the direction perpendicular to the axis, and there is no concern that the diameter of this portion will increase. In this case, if two bearings are provided along the longitudinal direction of the tool holding member, the tool holding member is supported by the two bearings in a stable shaft rotatable state. Since the head housing has an opening in a portion corresponding to the base side, the two bearings are easily assembled from the opening side into the head housing toward the front portion. be able to.

更に、前記係止解除部材を、前記ヘッドハウジングの開口部に、前記のように設けられるプッシュキャップと、該プッシュキャップを前記軸心方向に沿ってヘッドハウジングの外側に向け付勢する解除用弾性部材とを含むものとすれば、プッシュキャップの押圧操作によって後記する係止解除が簡易になされる。また、このプッシュキャップによって前記開口部が塞がれるから、外部からヘッドハウジング内への塵埃等の侵入が防止される。このプッシュキャップが、その内面に前記のような筒状の作用突部を備えているものとすれば、前記解除用弾性部材の付勢力に抗して押圧操作した際、前記作用突部が前記係止用爪部材に作用して、当該係止用爪部材を前記係止用弾性部材の付勢力に抗して遠心側に変位させることができる。これによって、係止用爪部材による切削回転工具の係止解除操作が、簡易且つ的確になされる。 Further, the locking release member is provided at the opening of the head housing with the push cap provided as described above, and the release elastic for urging the push cap toward the outside of the head housing along the axial direction. If it includes a member, the lock release described later is easily performed by pressing the push cap. Further, since the opening is closed by the push cap, entry of dust or the like into the head housing from the outside is prevented. If this push cap is provided with a cylindrical working projection as described above on its inner surface, when the push operation is performed against the urging force of the release elastic member, the working projection By acting on the locking claw member, the locking claw member can be displaced to the centrifugal side against the urging force of the locking elastic member. As a result, the unlocking operation of the cutting rotary tool by the locking claw member can be performed easily and accurately.

そして、前記解除用弾性部材を、金属性の板状ばね部材を打抜き加工した環状体を湾曲形成したものとすれば、その作成が簡易且つ安価になされる。この場合、前記環状体の外径部の形状が円形で且つ内径部の形状が前記作用突部を遊挿し得る楕円形であり、該楕円形の短径を正中として湾曲形成するようにすれば、湾曲によって環状体の内径部が前記作用突部に干渉することを防止することができる。これによって、ヘッドハウジングの小径化に伴い、当該解除用弾性部材の収納スペースが狭くなる場合でも、充分なバネ力を得ることができる。 If the release elastic member is formed by bending an annular body obtained by punching a metal plate-like spring member, the creation thereof is simple and inexpensive. In this case, if the shape of the outer diameter portion of the annular body is circular and the shape of the inner diameter portion is an ellipse in which the action protrusion can be loosely inserted, and the ellipse has a minor axis as a midline, Further, it is possible to prevent the inner diameter portion of the annular body from interfering with the action protrusion due to the bending. As a result, a sufficient spring force can be obtained even when the storage space for the release elastic member becomes narrow as the diameter of the head housing is reduced.

本発明に係る一実施形態の工具チャック装置を備えた歯科用ハンドピースの全体構成を示す断面図である。It is sectional drawing which shows the whole structure of the dental handpiece provided with the tool chuck apparatus of one Embodiment which concerns on this invention. 図１におけるＸ部の拡大断面図である。It is an expanded sectional view of the X section in FIG. （ａ）（ｂ）（ｃ）（ｄ）は同実施形態の工具チャック装置の分解斜視図であり、歯科用ハンドピースの先端ヘッド部に組み込む過程を示している。(A), (b), (c), and (d) are exploded perspective views of the tool chuck device of the same embodiment, showing a process of assembling into the distal end head portion of the dental handpiece. 図３（ｃ）におけるＹ−Ｙ線矢視拡大断面図である。FIG. 4 is an enlarged cross-sectional view taken along line YY in FIG. 本実施形態に用いられる工具保持部材の正面図である。It is a front view of the tool holding member used for this embodiment. 本実施形態に用いられる係止用爪部材の斜視図である。It is a perspective view of the nail | claw member for latch used for this embodiment. （ａ）は本実施形態に用いられる解除用弾性部材の作成過程を説明する図であり、（ｂ）（ｃ）は参考例における同様図である。(A) is a figure explaining the creation process of the elastic member for cancellation | release used for this embodiment, (b) (c) is the same figure in a reference example.

以下、本発明の工具チャック装置の実施の形態について図面に基づき説明する。先ず、本発明に係る工具チャック装置が組み込まれた歯科用（医科歯科用）ハンドピースの一例について図１及び図２を参照して説明する。図１及び図２において、歯科用ハンドピース１は、先端ヘッド部２と、該先端ヘッド部２に連接される細径のネック部３と、該ネック部３に連接され手指によって把持される把持部４とを備えている。そして、前記把持部４の基部には、先端ヘッド部２に装着される切削回転工具５を回転駆動させるためのモータユニット６が着脱自在に接続される。ハンドピース１にモータユニット６が連結された状態で歯科用インスツルメント７が構成される。このモータユニット６には、該モータユニット６に内蔵されるマイクロモータ８への電源供給用リード線８１、図示を省略する患部照射用ランプの電源供給用リード線、患部に噴霧注水させるための水管路及びエア管路等を内装するホース６１が連結されている。 Hereinafter, embodiments of a tool chuck device of the present invention will be described with reference to the drawings. First, an example of a dental (medical / dental) handpiece in which the tool chuck device according to the present invention is incorporated will be described with reference to FIGS. 1 and 2. 1 and 2, a dental handpiece 1 includes a tip head portion 2, a narrow neck portion 3 connected to the tip head portion 2, and a grip connected to the neck portion 3 and gripped by fingers. Part 4. A motor unit 6 for rotationally driving a cutting rotary tool 5 attached to the tip head portion 2 is detachably connected to the base portion of the grip portion 4. A dental instrument 7 is configured with the motor unit 6 connected to the handpiece 1. The motor unit 6 includes a power supply lead 81 for the micromotor 8 built in the motor unit 6, a power supply lead for an unillustrated affected part irradiation lamp, and a water pipe for spraying water to the affected part. The hose 61 which connects a path | route, an air pipe line, etc. is connected.

歯科用ハンドピース１は、把持部ハウジング４ａにネック部３を介してヘッドハウジング２０が連なってコントラアングル形に形成されている。把持部ハウジング４ａ内には、把持部４の基部にモータユニット６が接続されたときに、マイクロモータ８の出力軸８２にカップリング部９ａを介して連結される第１駆動伝達軸９が軸回転可能に内装されている。第１駆動伝達軸９の先端には第１減速ギヤ機構１０を介して第２駆動伝達軸１１が軸回転可能に連接され、更に、ネック部３に至る部分には、屈折部分の第２減速ギヤ機構１２を介して第３駆動伝達軸１３が軸回転可能に連接されている。前記第３駆動伝達軸１３は、把持部ハウジング４ａ内に軸受１４を介して軸回転可能に支持され、その先端部にはベベルギヤ１５が固設されている。把持部ハウジング４ａには、前記モータユニット６に設けられた不図示の照明用ランプ（例えば、ＬＥＤ）が発する照明光を前記ネック部３にまで導光する導光体（例えば、光ファイバ）１６が内装されている。この導光体１６によって導光された照明光は、その出光端１６ａから前記切削回転工具５の先端部に向け出射される。 The dental handpiece 1 is formed in a contra-angle shape with a head housing 20 connected to a grip part housing 4a via a neck part 3. In the gripping part housing 4a, when the motor unit 6 is connected to the base part of the gripping part 4, the first drive transmission shaft 9 connected to the output shaft 82 of the micromotor 8 via the coupling part 9a is provided. The interior is rotatable. A second drive transmission shaft 11 is connected to the tip of the first drive transmission shaft 9 via a first reduction gear mechanism 10 so as to be capable of rotating the shaft. A third drive transmission shaft 13 is connected via a gear mechanism 12 so as to be rotatable. The third drive transmission shaft 13 is supported in the gripping portion housing 4a through a bearing 14 so as to be rotatable. A bevel gear 15 is fixed to the tip of the third drive transmission shaft 13. A light guide (for example, an optical fiber) 16 that guides illumination light emitted from an unillustrated illumination lamp (for example, LED) provided in the motor unit 6 to the neck portion 3 is provided in the grip portion housing 4a. Is decorated. The illumination light guided by the light guide 16 is emitted from the light output end 16a toward the tip of the cutting rotary tool 5.

先端ヘッド部２のヘッドハウジング２０には、本実施形態の工具チャック装置１７が組み込まれている。この工具チャック装置１７について、図３〜図７をも参照して詳細に説明する。該工具チャック装置１７は、前記先端ヘッド部２のヘッドハウジング２０に軸回転可能に内装される工具保持部材１８と、係止用爪部材１９と、係止用弾性部材２１と、係止解除部材２２とを備える。前記工具保持部材１８は、前記切削回転工具５を同心的に挿通し得る内筒部１８ａを備えた中空円筒状とされ、その基端部１８ｂ側の胴部に内外に連通する開口部１８ｃが形成されている。更に、当該工具保持部材１８の長手方向の略中央部には、前記ベベルギヤ１５に噛み合う被伝達ベベルギヤ２３が一体に設けられている。前記係止用爪部材１９は、前記工具保持部材１８の開口部１８ｃに、前記内筒部１８ａに一部（以下、係止爪部１９１と言う）が臨んで、挿通された前記切削回転工具５の基端部５ａを係止するよう、該工具保持部材５の軸心Ｌに直交する方向にスライド自在に支持されている。前記係止用弾性部材２１は、前記係止用爪部材１９を前記工具保持部材１８の軸心Ｌ側に弾力付勢し、常時は前記係止爪部１９１が前記開口部１８ｃより前記内筒部１８ａ内に臨んだ状態に維持するよう機能する。そして、前記係止解除部材２２は、前記係止用爪部材１９を前記係止用弾性部材２１の付勢力に抗して前記工具保持部材１８の遠心側に変位させて前記切削回転工具５に対する係止を解除させるよう構成されている。 The tool chuck device 17 of this embodiment is incorporated in the head housing 20 of the distal end head portion 2. The tool chuck device 17 will be described in detail with reference to FIGS. The tool chuck device 17 includes a tool holding member 18, a locking claw member 19, a locking elastic member 21, and a locking release member that are rotatably mounted in the head housing 20 of the tip head portion 2. 22. The tool holding member 18 has a hollow cylindrical shape having an inner cylindrical portion 18a through which the cutting rotary tool 5 can be inserted concentrically, and an opening portion 18c communicating with the body portion on the base end portion 18b side is provided inside and outside. Is formed. Further, a transmitted bevel gear 23 that meshes with the bevel gear 15 is integrally provided at a substantially central portion in the longitudinal direction of the tool holding member 18. The cutting claw member 19 is inserted through the opening 18c of the tool holding member 18 with a part (hereinafter referred to as a locking claw portion 191) facing the inner cylinder portion 18a. 5 is supported so as to be slidable in a direction perpendicular to the axis L of the tool holding member 5 so that the base end portion 5a of the tool 5 is locked. The locking elastic member 21 elastically urges the locking claw member 19 toward the axis L side of the tool holding member 18, and the locking claw portion 191 is normally connected to the inner cylinder from the opening 18c. It functions to maintain the state facing the part 18a. Then, the locking release member 22 displaces the locking claw member 19 against the urging force of the locking elastic member 21 toward the distal side of the tool holding member 18 to the cutting rotary tool 5. It is comprised so that latching may be cancelled | released.

前記工具保持部材１８における前記係止用爪部材１９の支持部には、遠心方向に張出すフランジ部１８ｄが形成され、その上面は平坦面１８ｅとされ、該平坦面１８ｅは前記開口部１８ｃの開口下縁部と連続するように形成されている。なお、本明細書において、下なる用語は、先端ヘッド部２に対して切削回転工具５が装着される側を、また、上なる用語は、切削回転工具５が装着される側の反対側、即ち、工具保持部材１８の基端部１８ｂ側を、それぞれ意味する。前記フランジ部１８ｄの平坦面１８ｅ上であって、前記開口部１８ｃの両側縁部の近傍に２個の突起１８ｆ，１８ｆが***形成されている。この突起１８ｆ，１８ｆは、前記係止用爪部材１９が、前記フランジ部１８ｄ上で、前記工具保持部材１８に対して、前記軸心Ｌ回りに相対回転するのを防止するものである。また、前記工具保持部材１８における前記開口部１８ｃとは反対側の胴部であって、前記フランジ部１８ｄの下部近傍には、工具保持部材１８の内外に通じる第２の開口部１８ｇが形成されている。この第２の開口部１８ｇには、平面視して半月形状のキー部材２４が前記内筒部１８ａ内に臨むよう嵌め込まれる。該キー部材２４は、前記内筒部１８ａに臨む部分が、工具保持部材１８の内筒部１８ａに挿通される切削回転工具５の切欠部５ｂと整合し、そのキー的作用によって、工具保持部材１８と切削回転工具５とが、前記軸心Ｌ回りに一体回転するようになされている。前記キー部材２４の外周円弧形状部の径が、前記工具保持部材１８の外径と略同じかやや小とされ、これによって、キー部材２４が前記開口部１８ｇに嵌め込まれた状態では、該キー部材２４の外周面と、工具保持部材１８の外周面とが同じ面をなす。 A flange portion 18d projecting in the centrifugal direction is formed on a support portion of the locking claw member 19 in the tool holding member 18, and an upper surface thereof is a flat surface 18e, and the flat surface 18e is formed on the opening portion 18c. It is formed to be continuous with the lower edge of the opening. In the present specification, the lower term is the side on which the cutting rotary tool 5 is attached to the tip head portion 2, and the upper term is the opposite side of the side on which the cutting rotary tool 5 is attached, That is, the base end 18b side of the tool holding member 18 is meant. On the flat surface 18e of the flange portion 18d, two protrusions 18f and 18f are formed so as to protrude in the vicinity of both side edges of the opening portion 18c. The protrusions 18f and 18f prevent the locking claw member 19 from rotating relative to the tool holding member 18 around the axis L on the flange portion 18d. In addition, a second opening 18g that communicates with the inside and outside of the tool holding member 18 is formed in a body portion of the tool holding member 18 opposite to the opening 18c and in the vicinity of the lower portion of the flange portion 18d. ing. A half-moon shaped key member 24 is fitted into the second opening 18g so as to face the inner cylinder 18a in plan view. The key member 24 has a portion facing the inner cylinder portion 18a aligned with the notch portion 5b of the cutting rotary tool 5 inserted through the inner cylinder portion 18a of the tool holding member 18, and the key action causes the tool holding member. 18 and the cutting rotary tool 5 are configured to rotate integrally around the axis L. In the state in which the diameter of the outer peripheral arc-shaped portion of the key member 24 is substantially the same as or slightly smaller than the outer diameter of the tool holding member 18, the key member 24 is fitted in the opening 18 g. The outer peripheral surface of the member 24 and the outer peripheral surface of the tool holding member 18 are the same surface.

前記係止用爪部材１９は、平面視して円弧（扇形）形状をなし、本体部１９０と、該本体部１９０から内径側に向け延出される前記係止爪部１９１とよりなり、縦断面形状が略Ｌ字形に形成され、その下面は平坦面とされている。本体部１９０における内径側の上向角部には、斜面１９０ａが面取状に形成されている。また、前記係止爪部１９１は、前記工具保持部材１８の開口部１８ｃより内筒部１８内に侵入し得る形状とされ、その内径側の下向角部には、斜面１９１ａが面取状に形成されている。この斜面１９１ａを含む係止爪部１９１の内径側部分が前記工具保持部材１８の内筒部１８内に臨むようになされている。本体部１９０の外周部には、周溝１９０ｂが形成され、その周溝１９０ｂの周方向中央部には、該周溝１９０ｂを左右に分断する区画壁部１９０ｃが形成されている。 The locking claw member 19 has a circular arc (fan-shaped) shape in plan view, and includes a main body portion 190 and the locking claw portion 191 extending from the main body portion 190 toward the inner diameter side. The shape is substantially L-shaped, and the lower surface is a flat surface. An inclined surface 190a is formed in a chamfered shape at an upward corner portion on the inner diameter side of the main body 190. Further, the locking claw 191 has a shape that can enter the inner cylindrical portion 18 through the opening 18c of the tool holding member 18, and an inclined surface 191a is chamfered at a downward angle portion on the inner diameter side thereof. Is formed. An inner diameter side portion of the locking claw portion 191 including the inclined surface 191 a faces the inner cylinder portion 18 of the tool holding member 18. A circumferential groove 190b is formed on the outer peripheral portion of the main body 190, and a partition wall portion 190c that divides the circumferential groove 190b into left and right is formed at the circumferential center of the circumferential groove 190b.

前記係止用弾性部材２１は、バネ性ワイヤを開環リング状に形成したリングバネからなる。このリングバネ（係止用弾性部材）２１は、前記工具保持部材１８における基端部１８ｂの前記開口部１８ｃとは反対側から、前記係止爪部１９１が開口部１８ｃに連続する前記フランジ部１８ｄ上に置かれた係止用爪部材１９を抱え込むように装着される。このとき、リングバネ２１は、前記本体部１９０の周溝１９０ｂに嵌め入れられ、その開環端部２１ａ，２１ａは、前記区画壁部１９０ｃを隔てて互いに対峙するよう位置付けられる。当該リングバネ２１の開環端部２１ａ，２１ａとは反対側の中央部には、求心方向に向く屈曲部２１ｂが形成され、一方、前記基端部１８ｂの周面には、該屈曲部２１ｂが嵌り得る凹所１８ｈが形成されている。前記開環端部２１ａ，２１ａの前記区画壁部１９０ｃを隔てた対峙と、前記屈曲部２１ｂの凹所１８ｈへの嵌り込みとにより、リングバネ２１の前記基端部１８ｂの回りの位置変位が防止される。そして、このリングバネ２１が、前記工具保持部材１８に対して係止用爪部材１９を抱え込むように装着された状態では、前記係止用爪部材１９が、前記工具保持部材１８の軸心Ｌ方向に弾力付勢され、その係止爪部１９１が内筒部１８ａ内に臨んだ状態に維持される。 The locking elastic member 21 is a ring spring in which a spring wire is formed in a ring-opening ring shape. The ring spring (locking elastic member) 21 is formed on the flange 18d where the locking claw 191 is continuous with the opening 18c from the side of the base end 18b of the tool holding member 18 opposite to the opening 18c. It is mounted so as to hold the locking claw member 19 placed thereon. At this time, the ring spring 21 is fitted into the circumferential groove 190b of the main body 190, and the ring-opening end portions 21a and 21a are positioned so as to face each other across the partition wall portion 190c. A bent portion 21b facing in the centripetal direction is formed at the center of the ring spring 21 opposite to the ring-opening end portions 21a and 21a, while the bent portion 21b is formed on the peripheral surface of the base end portion 18b. A recess 18h that can be fitted is formed. Positional displacement of the ring spring 21 around the base end portion 18b is prevented by facing the ring-opening end portions 21a and 21a across the partition wall portion 190c and fitting the bent portion 21b into the recess 18h. Is done. When the ring spring 21 is mounted so as to hold the locking claw member 19 with respect to the tool holding member 18, the locking claw member 19 is in the direction of the axis L of the tool holding member 18. The latching claw portion 191 is maintained in a state of facing the inner cylinder portion 18a.

前記工具保持部材１８は、ヘッドハウジング２０内で上下の軸受２５，２６によって軸回転（軸心Ｌ回りの回転）可能に内装されている。前記ヘッドハウジング２０の上端部は開口し、この開口部２００の内面には雌ねじ部２０１が形成されている。そして、当該開口部２００に雄ねじ部２７ａを有する支持リング２７が、雄ねじ部２７ａ及び雌ねじ部２０１螺合によって一体に取付けられている。この支持リング２７の下部は、上側（開口部側）の前記軸受２５の外径面に外嵌されると共に軸受２５の上面の一部に当止している。また、支持リング２７の上部には、開環状のキャップリング２８が取付けられている。このキャップリング２８は、開環状態であることにより、求心方向に弾性変形（縮径）可能とされ、弾性変形させた状態で支持リング２７内に挿入される。挿入後、この弾性変形を解除すると弾性復元し、前記支持リング２７の内周に設けられた周溝２７ｂに、キャップリング２８の下端外周に設けられた外向鍔部２８１が没入係止される。これによって、該キャップリング２８が支持リング２７からの抜出不可に一体化される。 The tool holding member 18 is housed in the head housing 20 so as to be capable of axial rotation (rotation about the axis L) by upper and lower bearings 25 and 26. An upper end portion of the head housing 20 is opened, and a female screw portion 201 is formed on the inner surface of the opening portion 200. And the support ring 27 which has the external thread part 27a in the said opening part 200 is integrally attached by the external thread part 27a and the internal thread part 201 screwing together. The lower portion of the support ring 27 is fitted on the outer diameter surface of the bearing 25 on the upper side (opening side) and is in contact with a part of the upper surface of the bearing 25. An open ring cap ring 28 is attached to the upper portion of the support ring 27. Since the cap ring 28 is in the ring-opened state, it can be elastically deformed (reduced diameter) in the centripetal direction, and is inserted into the support ring 27 in an elastically deformed state. After the insertion, the elastic deformation is restored when the elastic deformation is released, and the outward flange 281 provided on the outer periphery of the lower end of the cap ring 28 is immersed and locked in the circumferential groove 27b provided on the inner periphery of the support ring 27. As a result, the cap ring 28 is integrated so that it cannot be removed from the support ring 27.

前記キャップリング２８には、円筒部２９０と、該円筒部２９０の一端（上端）開口部を塞ぐ蓋部２９１と、蓋部２９１の内面に下向きに突設された筒状の作用突部２９２とからなるプッシュキャップ２９が上方への抜出しが不能の状態で取付けられている。即ち、前記円筒部２９０の下端部には、内向の係止鍔部２９３が連設され、該係止鍔部２９３の内径側下向角部にテーパー面２９３ａが形成されている。また、前記キャップリング２８の上端外周に外向の係止鍔部２８２が連設され、該係止鍔部２８２の外径側上向角部にテーパー面２８２ａが形成されている。前記プッシュキャップ２９の円筒部２９０を前記支持リング２７内に挿入し、前記テーパー面２９３ａを前記キャップリング２８の前記テーパー面２８２ａに宛がい、円筒部２９０を強く押し下げる。これに伴い、テーパー面２９３ａ，２８２ａ同士のカム作用によって、前記キャップリング２８が縮径するように弾性変形し、プッシュキャップ２９の内向の係止鍔部２９３と前記キャップリング２８の外向の係止鍔部２８２とが噛み合うように係止し合う。これによって、プッシュキャップ２９がキャップリング２８に対して、上下の変位が許容された状態で、上方への抜出しが不能の状態で取付けられる。このように、プッシュキャップ２９のキャップリング２８に対する取付は、キャップリング２８の縮径によってなされるから、プッシュキャップ２９の外径側には、弾性変形による拡径を許容する為のスペースを確保する必要がない。従って、ヘッドハウジング２０の径大化を抑え、先端ヘッド部２をコンパクトに構成することができる。そして、前記プッシュキャップ２９とキャップリング２８との間に、前記解除用弾性部材としてのウェーブワッシャ３０がその環内に作用突部２９２を遊挿した状態で弾装され、プッシュキャップ２９は、このウェーブワッシャ３０によって常時上方に弾力付勢されている。 The cap ring 28 includes a cylindrical portion 290, a lid portion 291 that closes an opening at one end (upper end) of the cylindrical portion 290, and a cylindrical action projection portion 292 that projects downward from the inner surface of the lid portion 291. A push cap 29 is attached in a state in which it cannot be pulled out upward. That is, an inward locking collar portion 293 is connected to the lower end portion of the cylindrical portion 290, and a tapered surface 293a is formed on the inner diameter side downward corner portion of the locking collar portion 293. Further, an outward locking collar portion 282 is continuously provided on the outer periphery of the upper end of the cap ring 28, and a tapered surface 282 a is formed at the outer diameter side upward corner portion of the locking collar portion 282. The cylindrical portion 290 of the push cap 29 is inserted into the support ring 27, the tapered surface 293a is directed to the tapered surface 282a of the cap ring 28, and the cylindrical portion 290 is strongly pressed down. Along with this, the cap ring 28 is elastically deformed so that its diameter is reduced by the cam action between the tapered surfaces 293a and 282a, and the inward locking collar portion 293 of the push cap 29 and the outward locking of the cap ring 28 are performed. The hooks 282 are engaged with each other so as to mesh with each other. As a result, the push cap 29 is attached to the cap ring 28 in a state in which the push cap 29 is allowed to be displaced up and down and cannot be pulled out upward. As described above, the push cap 29 is attached to the cap ring 28 by reducing the diameter of the cap ring 28. Therefore, a space for allowing the diameter to be expanded by elastic deformation is secured on the outer diameter side of the push cap 29. There is no need. Therefore, the diameter increase of the head housing 20 can be suppressed and the tip head portion 2 can be configured compactly. A wave washer 30 as the release elastic member is elastically mounted between the push cap 29 and the cap ring 28 with the action protrusion 292 loosely inserted in the ring. The wave washer 30 is always elastically biased upward.

前記プッシュキャップ２９における作用筒部２９２の下端部の外径側角部はテーパー面２９２ａとされ、該プッシュキャップ２９を前記ウェーブワッシャ３０の付勢力に抗して押下げ操作すると、当該テーパー面２９２ａが前記係止用爪部材１９の斜面１９０ａに当接する。更に押下げ操作を継続すると、テーパー面２９２ａの斜面１９０ａに対するカム作用によって、前記係止用爪部材１９が前記リングバネ２１の付勢力に抗して、前記フランジ部１８ｄの平坦面１８ｅ上を遠心側にスライド変位する。これによって、後記するように、工具保持部材１８に挿入され切削回転工具５の係止用爪部材１９による係止保持が解除される。即ち、支持リング２７、キャップリング２８、プッシュキャップ２９及びウェーブワッシャ３０により係止解除部材２２が構成される。 A corner portion on the outer diameter side of the lower end portion of the working cylinder portion 292 in the push cap 29 is a tapered surface 292a. When the push cap 29 is pushed down against the urging force of the wave washer 30, the tapered surface 292a. Comes into contact with the inclined surface 190 a of the locking claw member 19. When the pressing operation is further continued, the locking claw member 19 resists the urging force of the ring spring 21 due to the cam action on the inclined surface 190a of the tapered surface 292a, so that the flat surface 18e of the flange portion 18d moves on the centrifugal side. Displace to slide. Thereby, as will be described later, the locking holding by the locking claw member 19 of the cutting rotary tool 5 inserted into the tool holding member 18 is released. That is, the locking release member 22 is configured by the support ring 27, the cap ring 28, the push cap 29, and the wave washer 30.

前記のように構成される工具チャック装置１７のヘッドハウジング２０に対する組付け要領について、図３（ａ）（ｂ）（ｃ）（ｄ）を参照して説明する。図３（ａ）（ｂ）において、先ず、工具保持部材１８の前記第２の開口部１８ｇにキー部材２４を外側より嵌め込み、更に、上側の軸受２５を工具保持部材１８の下端より嵌装してフランジ部１８ｄの下面に当接させる。この状態で、前記キー部材２４は、前記上側の軸受２５と第２の開口部１８ｇの開口縁部とによって挟まれるように保持されるから、その脱落が阻止される。次いで、間座３１を工具保持部材１８の下端より嵌装して前記軸受２５の内径側に当接させ、更に、前記被伝達ベベルギヤ２３を、圧嵌め若しくはキー結合によって、工具保持部材１８に相対回転不能の状態で嵌装する。そして、下側の軸受２６を工具保持部材１８に嵌装して前記工具保持部材１８に当接させ、工具保持部材１８の下端部に止めリング３２を圧嵌めによって一体に嵌装する。この状態では、止めリング３２によって、それより上に嵌装された前記各部品の抜け落ちが防止される。一方、前記支持リング２７に、前記の要領でキャップリング２８を嵌め込み、このキャップリング２８に、ウェーブワッシャ３０を圧縮状態で介在させて前記プッシュキャップ２９を前記要領で取付け、係止解除部材２２を組み立てておく。 A procedure for assembling the tool chuck device 17 configured as described above with respect to the head housing 20 will be described with reference to FIGS. 3 (a), (b), (c), and (d). 3A and 3B, first, the key member 24 is fitted into the second opening 18g of the tool holding member 18 from the outside, and the upper bearing 25 is fitted from the lower end of the tool holding member 18. To contact the lower surface of the flange portion 18d. In this state, the key member 24 is held so as to be sandwiched between the upper bearing 25 and the opening edge of the second opening 18g, so that the drop-off is prevented. Next, the spacer 31 is fitted from the lower end of the tool holding member 18 and is brought into contact with the inner diameter side of the bearing 25. Further, the transmitted bevel gear 23 is moved relative to the tool holding member 18 by press fitting or key coupling. Fit in a non-rotatable state. Then, the lower bearing 26 is fitted to the tool holding member 18 and brought into contact with the tool holding member 18, and the stop ring 32 is fitted to the lower end portion of the tool holding member 18 by press fitting. In this state, the retaining ring 32 prevents the parts fitted above it from falling off. On the other hand, the cap ring 28 is fitted to the support ring 27 as described above, and the push cap 29 is attached to the cap ring 28 with the wave washer 30 interposed in the compressed state, and the unlocking member 22 is attached. Assemble.

図３（ｃ）において、前記係止用爪部材１９を、前記工具保持部材１８における前記フランジ部１８ｄの上に載せ、この状態で前記開口部１８ｃ側にスライドさせ、その係止爪部１９１が工具保持部材１８の内筒部１８ａ内に臨むように、前記開口部１８ｃに嵌め込む。更に、前記リングバネ２１を、前記工具保持部材１８の前記基端部１８ｂ及び当該係止用爪部材１９を合わせて、これらを抱きかかえるように弾性的に嵌め合せる。このリングバネ２１の縮径弾力により、係止用爪部材１９は、前記係止爪部１９１が工具保持部材１８の内筒部１８ａ内に臨み、前記フランジ部１８ｄ上で前記工具保持部材１８の前記基端部１８ｂに拘束された状態に維持される。このように前記各部品が組付けられた工具保持部材１８を、その先端よりヘッドハウジング２０内に挿入し、次いで、既に組み立てられた係止解除部材２２を、前記支持リング２７の雄ねじ部２７ａをヘッドハウジング２０における前記開口部２００の雌ねじ部２０１に螺合することによって、ヘッドハウジング２０に取付ける。これによって、ヘッドハウジング２０の開口部２００が閉塞され、図３（ｄ）及び図２に示すように先端ヘッド部２に対する工具チャック装置１７の組付けが完了する。 In FIG. 3C, the locking claw member 19 is placed on the flange portion 18d of the tool holding member 18 and is slid to the opening 18c side in this state. The opening 18c is fitted into the inner cylinder 18a of the tool holding member 18. Further, the ring spring 21 is elastically fitted so as to hold the base end portion 18b of the tool holding member 18 and the locking claw member 19 together. Due to the reduced diameter elasticity of the ring spring 21, the locking claw member 19 has the locking claw portion 191 facing the inner cylinder portion 18 a of the tool holding member 18, and the flange holding portion 18 d above the tool holding member 18. It is maintained in a state restrained by the base end portion 18b. The tool holding member 18 assembled with the components as described above is inserted into the head housing 20 from the tip, and then the already-engaged locking release member 22 is inserted into the male threaded portion 27a of the support ring 27. The head housing 20 is attached to the head housing 20 by being screwed into the female screw portion 201 of the opening 200. As a result, the opening 200 of the head housing 20 is closed, and the assembly of the tool chuck device 17 to the tip head portion 2 is completed as shown in FIGS.

前記のように工具チャック装置１７の組付けが完了した先端ヘッド部２は、ネック部３を介して前記歯科用ハンドピース１の前記把持部４の先端に連接される。この連接状態で、前記把持部４内に装備されるベベルギヤ１５が、前記被伝達ベベルギヤ２３に噛み合う。これによって、前記マイクロモータ８から駆動伝達された前記第３駆動伝達軸１３の軸回転は、ベベルギヤ１５及び被伝達ベベルギヤ２３の噛み合い部を介し第３駆動伝達軸１３の軸に直交する軸心Ｌ回りの回転に変換される。従って、前記工具保持部材１８は、上下の軸受２５，２６によって支持された状態で、前記マイクロモータ８の回転動力を受けて前記軸心Ｌ回りに回転する。このような工具チャック装置１７が組付けられた先端ヘッド部には、歯科用の前記切削回転工具５が装着される。該切削回転工具５は、コントラアングルバー、或いは、ラッチバーと称され、図１及び図２に示すように、その基端部５ａに前記係止用爪部材１９の係止爪部１９１が嵌り込み得る周溝５ｃを備えている。また、前記基端部５ａの上端から前記周溝５ｃの下方部にかけて、平面視して半月形状（前記キー部材２４の平面視形状と整合する形状）の切欠部５ｂが形成されている。更に、前記基端部５ａの上端角部にはテーパー面５ｄが面取り状に形成されている。当該切削回転工具５のシャンク部は中実円柱体でありその外径は、前記工具保持部材１８における内筒部１８ａの内径と同じ若しくは若干小とされている。 As described above, the distal end head portion 2 in which the assembly of the tool chuck device 17 is completed is connected to the distal end of the grasping portion 4 of the dental handpiece 1 through the neck portion 3. In this connected state, the bevel gear 15 provided in the grip portion 4 meshes with the transmitted bevel gear 23. As a result, the shaft rotation of the third drive transmission shaft 13 transmitted and transmitted from the micro motor 8 causes the axis L perpendicular to the axis of the third drive transmission shaft 13 via the meshing portion of the bevel gear 15 and the transmitted bevel gear 23. Converted to rotation around. Accordingly, the tool holding member 18 is rotated around the axis L by receiving the rotational power of the micromotor 8 while being supported by the upper and lower bearings 25 and 26. The dental rotary cutting tool 5 is attached to the tip head portion to which such a tool chuck device 17 is assembled. The cutting rotary tool 5 is called a contra-angle bar or a latch bar. As shown in FIGS. 1 and 2, the locking claw portion 191 of the locking claw member 19 is fitted into the base end portion 5a. A circumferential groove 5c is provided. In addition, a cutout portion 5b having a half-moon shape (a shape matching the plan view shape of the key member 24) is formed in plan view from the upper end of the base end portion 5a to the lower portion of the circumferential groove 5c. Further, a tapered surface 5d is formed in a chamfered shape at the upper end corner of the base end 5a. The shank portion of the cutting rotary tool 5 is a solid cylindrical body, and the outer diameter thereof is the same as or slightly smaller than the inner diameter of the inner cylinder portion 18a of the tool holding member 18.

前記切削回転工具５を前記先端ヘッド部２に装着するに際して、先ず、切削回転工具５を手指で持ち、前記基端部５ａを前記工具保持部材１８の内筒部１８ａに、その下端部より挿入する。該切削回転工具５を前記軸心Ｌ回りに回しながら挿入を継続し、前記切欠部５ｂが前記キー部材２３に整合する位置になったとき、切削回転工具５を強く押し込む。このとき、切削回転工具５の前記テーパー面５ｄが、前記係止用爪部材１９の前記斜面１９１ａに当接し、テーパー面５ｄの斜面１９１ａに対するカム作用によって、係止用爪部材１９が前記フランジ部１８ｄの平坦面１８ｅ上をスライドして遠心側に変位する。この変位は、前記リングバネ２１の縮径弾力に抗してなされ、図４の２点鎖線で示すように、係止用爪部材１９の係止爪部１９１が前記工具保持部材１８の内筒部１８ａから退避し、且つ、リングバネ２１が押し広げられる状態でなされる。このように、係止用爪部材１９が遠心方向に変位した状態で更に切削回転工具５を押し込むと、基端部５ａが係止用爪部材１９の支持位置を通過し、周溝５ｃがこの支持位置に達する。ここで、前記係止用爪部材１９が、前記リングバネ２１の復元弾力により求心側に変位し、係止爪部１９１が前記周溝５ｃに嵌り込み、切削回転工具５の装着が完了する。この装着状態では、係止爪部１９１が前記周溝５ｃに嵌り込むことによって切削回転工具５の抜け落ちが阻止され、また、キー部材２４の切欠部５ｂに対する整合によって、工具保持部材１８と切削回転工具５との相対回転が不可とされる。従って、前記マイクロモータ８の回転動力は、前記工具保持部材１８を介して切削回転工具５に伝達され、該切削回転工具５の前記軸心Ｌ回りの回転が安定的になされ、歯牙等の切削診療に供される。 When attaching the cutting rotary tool 5 to the distal end head portion 2, first, hold the cutting rotary tool 5 with fingers, and insert the base end portion 5 a into the inner cylinder portion 18 a of the tool holding member 18 from the lower end portion thereof. To do. Insertion is continued while turning the cutting rotary tool 5 around the axis L, and when the cutout portion 5b is aligned with the key member 23, the cutting rotary tool 5 is pushed in strongly. At this time, the tapered surface 5d of the cutting rotary tool 5 abuts on the inclined surface 191a of the locking claw member 19, and the locking claw member 19 is moved to the flange portion by a cam action on the inclined surface 191a of the tapered surface 5d. It slides on the flat surface 18e of 18d and is displaced to the centrifugal side. This displacement is made against the reduced diameter elasticity of the ring spring 21, and as shown by a two-dot chain line in FIG. 4, the locking claw portion 191 of the locking claw member 19 is connected to the inner cylinder portion of the tool holding member 18. It is made in a state where it is retracted from 18a and the ring spring 21 is pushed out. In this way, when the cutting rotary tool 5 is further pushed in with the locking claw member 19 displaced in the centrifugal direction, the base end portion 5a passes through the support position of the locking claw member 19, and the circumferential groove 5c Reach support position. Here, the locking claw member 19 is displaced to the centripetal side by the restoring elasticity of the ring spring 21, and the locking claw portion 191 is fitted into the circumferential groove 5c, whereby the mounting of the cutting rotary tool 5 is completed. In this mounted state, the locking claw portion 191 is fitted into the circumferential groove 5c to prevent the cutting rotary tool 5 from falling off, and the tool member 18 and the cutting rotation are aligned by the alignment of the key member 24 with the notch portion 5b. Relative rotation with the tool 5 is disabled. Therefore, the rotational power of the micromotor 8 is transmitted to the cutting rotary tool 5 through the tool holding member 18, and the rotation of the cutting rotary tool 5 around the axis L is stably performed, so that cutting of teeth and the like is performed. Provided for medical care.

このように、切削回転工具５の軸回転により歯牙等の切削診療を行うに際しては、前記のように先端ヘッド部２がコンパクトに構成されるから、診療時の視野が大きく確保される。また、切削回転工具５が工具保持部材１８と共に一体に軸回転するから、該切削回転工具５のシャンク部（工具保持部材１８に挿通される部分）の摩耗が少なく、切削回転工具５の耐久性が向上する。しかも、切削回転工具５が工具保持部材１８に安定的に保持されるから、安全であり、且つ、切削回転工具５の芯ぶれが少なく、患部の疼痛が緩和されると共に、破折が減少し、軸受２５，２６の耐久性も向上する。 As described above, when performing cutting medical treatment of teeth and the like by rotating the cutting rotary tool 5, the distal end head portion 2 is configured compactly as described above, so that a large visual field at the time of medical treatment is secured. In addition, since the cutting rotary tool 5 rotates together with the tool holding member 18, the shank portion of the cutting rotary tool 5 (the portion inserted through the tool holding member 18) is less worn, and the durability of the cutting rotary tool 5 is improved. Will improve. Moreover, since the cutting rotary tool 5 is stably held by the tool holding member 18, it is safe, and the cutting rotary tool 5 has less runout, the pain of the affected area is alleviated, and fractures are reduced. The durability of the bearings 25 and 26 is also improved.

前記切削回転工具５の取外しは、前記のように、前記係止解除部材２２を構成するプッシュキャップ２９を手指でヘッドハウジング２０側に強く押し込むことによってなされる。このとき、プッシュキャップ２９における作用突部２９２の作用によって、係止用爪部材１９が、遠心方向に変位して（図４の２点鎖線参照）、係止爪部１９１の切削回転工具５に対する係止が解除される。このように、切削回転工具５の装着や取外しの際における係止用爪部材１９の変位量は、図４の２点鎖線で示すようにわずかである。また、リングバネ２１の拡開量も小さく、しかも、リングバネ２１の拡開部分は、係止用爪部材１９の前記周溝１９０ｂに嵌め入れられているから、拡開しても係止用爪部材１９の周壁からの突出量が少ない。従って、これら変位量や拡開量を許容する為の大きなスペースを係止用爪部材１９の支持部の周囲に確保する必要がなく、これによって、先端ヘッド部２の径大化を抑えることができる。そして、前記係止用爪部材１９は、前記２個の突起１８ｆ、１８ｆによって、前記軸心Ｌに直交する方向へのスライド変位は許容されながらも、前記工具保持部材１８との前記軸心回りの相対回転を不能とされている．従って、回転中に不意に係止解除操作がなされても、相対回転によって、当該係止用爪部材１９がその周辺部材に対してくさびのように食い込んで戻らなくなるような不測の事態を生じる懸念がない。 As described above, the cutting rotary tool 5 is removed by strongly pushing the push cap 29 constituting the locking release member 22 toward the head housing 20 with fingers. At this time, due to the action of the action protrusion 292 in the push cap 29, the locking claw member 19 is displaced in the centrifugal direction (refer to the two-dot chain line in FIG. 4), and the locking claw 191 with respect to the cutting rotary tool 5 is displaced. The lock is released. Thus, the displacement amount of the locking claw member 19 when the cutting rotary tool 5 is mounted or removed is small as shown by the two-dot chain line in FIG. Further, the amount of expansion of the ring spring 21 is small, and the expanded portion of the ring spring 21 is fitted in the circumferential groove 190b of the locking claw member 19, so that the locking claw member can be opened even if it is expanded. There is little protrusion amount from 19 surrounding walls. Therefore, it is not necessary to secure a large space around the support portion of the locking claw member 19 to allow the displacement amount and the expansion amount, thereby suppressing an increase in the diameter of the tip head portion 2. it can. Then, the locking claw member 19 is allowed to slide around in the direction perpendicular to the axis L by the two protrusions 18f and 18f, but the axis around the tool holding member 18 is allowed. The relative rotation of is impossible. Therefore, even if the unlocking operation is unexpectedly performed during the rotation, the relative rotation may cause an unexpected situation in which the locking claw member 19 does not bite into the peripheral members like a wedge and return. There is no.

前記係止解除部材２２を構成するウェーブワッシャ３０は、金属性の板状ばね部材を打抜き加工した環状体からなる。図７（ａ）の左図に示すように、打抜かれた状態の環状体３００は、外径部３０１の形状が円形（真円形）で且つ内径部３０２の形状が前記プッシュキャップ２９の筒状の作用突部２９２を遊挿し得る楕円形とされている。そして、本実施形態のウェーブワッシャ３０は、該環状体３００を、図７（ａ）の右図に示すように、前記楕円形の短径Ｄを正中として湾曲して形成されたものである。このように、内径部３０２が楕円形で、この楕円形の短径Ｄを正中として湾曲しても、内径部３０２が前記作用突部２９２に干渉することがなく、所望のバネ応力を確保することができる。因みに、図７（ｂ）の左図に示すように、環状体３００Ａの外径部３０１Ａ及び内径部３０２Ａを共に同心の円形とし、内径部３０２Ａの径を大きくすると、湾曲させても図７（ｂ）の右図に示すように、得られたウェーブワッシャ３０Ａの内径部３０２Ａの作用突部２９２に対する干渉を防ぐことができる。しかし、外径部３０１Ａの径は周辺部品との制約で大きくできないので、環状体３００Ａの幅が小さくなり、曲げ部の応力がオーバーし、所望の荷重が得られなくなることがある。また、図７（ｃ）の左図に示すように、環状体３００Ｂの幅を確保した上で、内径部３０２Ｂを円形とすると、図７（ｃ）の右図に示すように、湾曲させた際、得られたウェーブワッシャ３０Ｂの内径部３０２Ｂが作用突部２９２に干渉する。従って、本実施形態のウェーブワッシャ３０の原形たる環状体３００としては、図７（ａ）の左図に示すような形状のものが、限られたスペース内に組み込むことができる上に、所望のバネ力を得ることができることから、最適であるということができる。 The wave washer 30 constituting the locking release member 22 is made of an annular body obtained by punching a metal plate spring member. As shown in the left figure of FIG. 7A, the punched annular body 300 has a circular outer shape (circular shape) 301 and a cylindrical shape of the inner diameter portion 302 of the push cap 29. The operating protrusion 292 is oval and can be loosely inserted. The wave washer 30 of the present embodiment is formed by bending the annular body 300 with the elliptical minor axis D as the median as shown in the right figure of FIG. Thus, even if the inner diameter portion 302 is elliptical and is curved with the elliptical short diameter D as the middle, the inner diameter portion 302 does not interfere with the action protrusion 292, and a desired spring stress is ensured. be able to. Incidentally, as shown in the left diagram of FIG. 7B, when the outer diameter portion 301A and the inner diameter portion 302A of the annular body 300A are both concentric circles and the diameter of the inner diameter portion 302A is increased, even if the inner diameter portion 302A is curved, FIG. As shown to the right figure of b), the interference with respect to the action protrusion 292 of the inner diameter portion 302A of the obtained wave washer 30A can be prevented. However, since the diameter of the outer diameter portion 301A cannot be increased due to restrictions with peripheral parts, the width of the annular body 300A is reduced, the bending portion stress is exceeded, and a desired load may not be obtained. Further, as shown in the left diagram of FIG. 7C, when the inner diameter portion 302B is made circular while securing the width of the annular body 300B, it is curved as shown in the right diagram of FIG. 7C. At this time, the inner diameter portion 302B of the obtained wave washer 30B interferes with the action protrusion 292. Therefore, as the annular body 300 which is the original shape of the wave washer 30 of the present embodiment, the shape shown in the left figure of FIG. 7A can be incorporated in a limited space, and a desired shape can be obtained. Since the spring force can be obtained, it can be said that it is optimal.

尚、前記実施形態では、切削回転工具５の回転駆動源をマイクロモータ８としたが、これに限らず、エアモータ、エアタービン等のその他の駆動手段を駆動源とすることも可能である。また、解除用弾性部材としてウェーブワッシャ３０を用いた例を示したが、圧縮コイルスプリングや板バネ等も採用可能である。更に、工具保持部材１８及びその周辺部品の構造も図例のものに限定されず、本発明の趣旨を逸脱しない限り、他の構造のものも採用可能である。また、係止用爪部材１９の相対回転を防止する規制手段として、図例のような２個の突起１８ｆを採用したがこれに限られるものではない。例えば、係止用爪部材１９の軸心Ｌに直交する方向へのスライド変位を許容し得るものであれば、フランジ部１８ｄと係止用爪部材１９との間に、凹凸の噛み合い構造を形成したり、その他のガイド構造を採用することも可能である。加えて、本発明の工具チャック装置が採用される医科歯科用ハンドピースとして、図例のような歯科用ハンドピースを例に採ったが、他の医科歯科用ハンドピースにも好ましく採用される。 In the above-described embodiment, the rotational drive source of the cutting rotary tool 5 is the micromotor 8. However, the present invention is not limited to this, and other drive means such as an air motor and an air turbine can be used as the drive source. Moreover, although the example which used the wave washer 30 as an elastic member for cancellation | release was shown, a compression coil spring, a leaf | plate spring, etc. are employable. Furthermore, the structure of the tool holding member 18 and its peripheral parts is not limited to that shown in the drawings, and other structures can be employed without departing from the spirit of the present invention. Further, as the restricting means for preventing the relative rotation of the locking claw member 19, the two protrusions 18f as shown in the figure are adopted, but the invention is not limited to this. For example, as long as the slide displacement in the direction perpendicular to the axis L of the locking claw member 19 can be allowed, an uneven engagement structure is formed between the flange portion 18d and the locking claw member 19. It is also possible to adopt other guide structures. In addition, as a medical / dental handpiece in which the tool chuck device of the present invention is employed, a dental handpiece as shown in the figure is taken as an example, but it is preferably employed in other medical / dental handpieces.

１歯科用ハンドピース
２先端ヘッド部
２０ヘッドハウジング
２００開口部
５切削回転工具
１７工具チャック装置
１８工具保持部材
１８ａ内筒部
１８ｂ基端部
１８ｃ開口部
１８ｄフランジ部
１８ｅ平坦面
１８ｆ突起（規制手段）
１９係止用爪部材
１９１係止爪部（係止用爪部材の一部）
２１リングバネ（係止用弾性部材）
２２係止解除部材
２５，２６軸受
２９プッシュキャップ
２９２作用突部
３０ウェーブワッシャ（解除用弾性部材）
３００環状体
３０１外径部
３０２内径部
Ｄ短径
Ｌ軸心 DESCRIPTION OF SYMBOLS 1 Dental handpiece 2 Tip head part 20 Head housing 200 Opening part 5 Cutting rotation tool 17 Tool chuck apparatus 18 Tool holding member 18a Inner cylinder part 18b Base end part 18c Opening part 18d Flange part 18e Flat surface 18f Protrusion (regulation means)
19 Claw member for locking 191 Locking claw part (part of claw member for locking)
21 Ring spring (elastic member for locking)
22 Unlocking member 25, 26 Bearing 29 Push cap 292 Working protrusion 30 Wave washer (elastic member for releasing )
300 annular body 301 outer diameter portion 302 inner diameter portion D minor diameter L axis

Claims

医科歯科用ハンドピースの先端ヘッド部に設けられ、切削回転工具を着脱自在に装着し得る工具チャック装置であって、
前記先端ヘッド部に軸回転可能に内装され、前記切削回転工具を同心的に挿通し得る内筒部を備えた中空円筒状の工具保持部材と、
前記工具保持部材の基端部側の胴部に内外に連通するよう形成された開口部に、前記内筒部に一部が臨んで、挿通された前記切削回転工具の基端部を係止するよう、該工具保持部材の軸心に直交する方向にスライド自在に支持される係止用爪部材と、
前記係止用爪部材を前記工具保持部材の軸心側に弾力付勢する係止用弾性部材と、
前記係止用爪部材を前記係止用弾性部材の付勢力に抗して前記工具保持部材の遠心側に変位させて前記切削回転工具に対する係止を解除させる係止解除部材と、を備え、
前記工具保持部材における前記係止用爪部材の支持部には、遠心方向に張出す平坦面を備えたフランジ部が形成され、前記係止用爪部材は当該フランジ部の平坦面に沿ってスライド可能に支持されており、
前記フランジ部の平坦面上には、前記係止用爪部材と前記工具保持部材との前記軸心回りの相対回転を不能とする規制手段として、前記係止用爪部材の前記軸心の回りの両端部に当接するよう形成された２個の突起が設けられており、
前記係止用爪部材の外周部には、周溝と周溝を分断する区画壁部とが形成され、
前記係止用弾性部材は、前記周溝に嵌め入れられ、かつ開環端部が前記区画壁部を隔てて互いに対峙するように位置付けられる開環リング状に形成され、
前記工具保持部材の周面には、前記係止用弾性部材に求心方向に向くように形成された屈曲部が嵌り込む凹所が形成されていることを特徴とする工具チャック装置。 A tool chuck device that is provided at the distal end head portion of a medical / dental handpiece and that can be detachably mounted with a cutting rotary tool,
A hollow cylindrical tool holding member provided with an inner cylinder part that is internally mounted in the tip head part so as to be axially rotatable and that can be inserted concentrically with the cutting rotary tool;
A part of the inner cylinder portion faces the opening formed to communicate with the body portion on the base end portion side of the tool holding member, and the base end portion of the inserted cutting rotary tool is locked. A locking claw member that is slidably supported in a direction perpendicular to the axis of the tool holding member,
A locking elastic member that elastically biases the locking claw member toward the axial center of the tool holding member;
A locking release member that releases the locking to the cutting rotary tool by displacing the locking claw member against the urging force of the locking elastic member to the distal side of the tool holding member,
A flange portion having a flat surface extending in the centrifugal direction is formed on a support portion of the locking claw member in the tool holding member, and the locking claw member slides along the flat surface of the flange portion. Supported as possible,
On the flat surface of the flange portion, as a restricting means for disabling relative rotation of the locking claw member and the tool holding member around the axis, the rotation of the locking claw member around the axis Two protrusions formed so as to abut on both ends of the
On the outer peripheral portion of the locking claw member, a circumferential groove and a partition wall portion that divides the circumferential groove are formed,
The locking elastic member is formed in a ring-opening ring shape that is fitted in the circumferential groove and positioned so that the ring-opening end portions face each other across the partition wall portion,
The tool chuck device according to claim 1, wherein a recess is formed in the peripheral surface of the tool holding member so that a bent portion formed so as to face the centripetal direction is fitted to the locking elastic member .

請求項１に記載の工具チャック装置において、
前記先端ヘッド部はヘッドハウジングを備え、前記工具保持部材は、当該ヘッドハウジングに、前記係止用爪部材の支持部より先側部分に設けられる軸受を介して軸回転可能に内装されていることを特徴とする工具チャック装置。 The tool chuck device according to claim 1 ,
The distal end head portion includes a head housing, and the tool holding member is provided in the head housing so as to be rotatable about a shaft via a bearing provided at a front side portion of the support portion of the locking claw member. A tool chuck device characterized by the above.

請求項２に記載の工具チャック装置において、
前記軸受は、前記工具保持部材の長手方向に沿って２個設けられ、前記ヘッドハウジングは、前記基端部側に相当する部分に開口部を有し、前記２個の軸受は、当該開口部側から前記ヘッドハウジング内の前記先側部分に向け組み付けられていることを特徴とする工具チャック装置。 The tool chuck apparatus according to claim 2 ,
Two of the bearings are provided along the longitudinal direction of the tool holding member, the head housing has an opening in a portion corresponding to the base end side, and the two bearings have the opening. A tool chuck device assembled from the side toward the front side portion in the head housing.

請求項３に記載の工具チャック装置において、
前記係止解除部材は、前記ヘッドハウジングの開口部に、前記工具保持部材の軸心方向に沿って変位可能且つ当該開口部を塞ぐように設けられるプッシュキャップと、該プッシュキャップを前記軸心方向に沿って前記ヘッドハウジングの外側に向け付勢する解除用弾性部材とを含み、前記プッシュキャップは、その内面に筒状の作用突部を備え、前記解除用弾性部材の付勢力に抗して押圧操作された際、前記作用突部が前記係止用爪部材に作用して、当該係止用爪部材を前記係止用弾性部材の付勢力に抗して遠心側に変位させるよう構成されていることを特徴とする工具チャック装置。 The tool chuck device according to claim 3 , wherein
The unlocking member includes a push cap provided at an opening of the head housing so as to be displaceable along the axial direction of the tool holding member and close the opening, and the push cap in the axial direction And a release elastic member for urging the head housing toward the outside of the head housing, and the push cap has a cylindrical action protrusion on its inner surface, and resists the urging force of the release elastic member. When the pressing operation is performed, the operating protrusion acts on the locking claw member, and the locking claw member is displaced to the centrifugal side against the urging force of the locking elastic member. A tool chuck device characterized by comprising:

請求項４に記載の工具チャック装置において、
前記解除用弾性部材が、金属性の板状ばね部材を打抜き加工した環状体からなり、当該環状体の外径部の形状が円形で且つ内径部の形状が前記作用突部を遊挿し得る楕円形であり、該楕円形の短径を正中として湾曲形成されたものであることを特徴とする工具チャック装置。 The tool chuck device according to claim 4 , wherein
The release elastic member is formed of an annular body obtained by punching a metal plate-like spring member, and the shape of the outer diameter portion of the annular body is circular, and the shape of the inner diameter portion is an ellipse that can loosely insert the action protrusion. A tool chuck device characterized by having a shape and being curved with the elliptical minor axis as the middle.