JP2004021115A

JP2004021115A - Lens barrel device

Info

Publication number: JP2004021115A
Application number: JP2002178965A
Authority: JP
Inventors: Kazuyuki Iwasa; 岩佐　和行
Original assignee: Olympus Corp
Current assignee: Olympus Corp
Priority date: 2002-06-19
Filing date: 2002-06-19
Publication date: 2004-01-22
Anticipated expiration: 2022-06-19
Also published as: JP3939206B2

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the disengagement of a cam follower with a simple constitution. <P>SOLUTION: A first wall surface 123 on which the taper 13c of a cam follower 13 sliding contacts is formed on a first frame member 10, and a cam groove 12 having a second wall surface 123 nearly parallel with a die removal direction is formed continuously to the first wall surface 122. The taper of the cam follower 13 of the second frame member 11 is engaged with the groove 12 so that the taper of the cam follower 13 sliding contacts on the cam groove 12. Thus the first and the second frame members 10 and 11 are combined and arranged to move relatively. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、例えば直線移動自在な枠部材を備える鏡筒装置に関する。
【０００２】
【従来の技術】
この種の鏡筒装置には、円筒状の枠部材の直線移動を制御する手段として、光軸と斜行するカム溝を枠部材に形成し、このカム溝に対してカムフォロワを摺動自在に係合配置することにより、枠部材の直線移動するように構成される。このカム溝を用いた鏡筒装置においては、その枠部材を成形型を用いてモールド成形することにより、コスト的に安価な製造が可能となる。
【０００３】
ところで、こような鏡筒装置にあっては、枠部材のカム溝を形成する際、成形型の突部を、枠部材のカム溝から抜き取る型抜き取り作業を考慮し、枠部材のカム溝の開口側を、アンダーにならないように所定の角度だけ傾斜させて形成することにより、製品からの型抜きが可能なように構成される。
【０００４】
このため、枠部材のカム溝に対してカムフォロワを摺動自在に挿着した組立て状態において、衝撃や落下等の不用意（不用）な外力が付与されたりすると、カムフォロワが、カム溝から抜けてしまうという不具合を有する。
【０００５】
【発明が解決しようとする課題】
以上述べたように、従来の鏡筒装置では、カムフォロワがカム溝から抜ける虞があるという問題を有する。
【０００６】
この発明は上記の事情に鑑みてなされたもので、簡易な構成で、カムフォロワの抜け防止を図り得るようにした鏡筒装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
この発明は、所定幅の底部を有し、互いに向き合い上記底部から周表面に向かって、その幅を広げるようにそれぞれ勾配を有した一対の第１の斜面と、この一対の第１の斜面の一方の面より連続して形成され、上記幅の内方向に向かって勾配を有する第２の斜面とからなるカム溝画設けられた枠部材を備えて鏡筒装置を構成した。
【０００８】
上記構成によれば、枠部材は、そのカム溝の第１の斜面に対して略円錐台形状のカムフォロワのテーパ面が摺接して移動され、不用な外力が付与されると、該カムフォロワの大径部が第２の斜面に規制されて抜けが阻止される。これにより、不用な外力に対するカムフォロワの抜けが効果的に防止される。
【０００９】
また、この発明は、所定幅の底部を有し、互いに向き合い、上記底部から周表面に向かって、その幅を広げるようにそれぞれ勾配を有した一対の第１の斜面と、この一対の第１の斜面の一方の面より連続して形成され、上記幅の内方向に向かって勾配を有する第２の斜面とからなるカム溝が設けられた第１の枠部材と、最大径が上記カム溝中に位置し、第１の斜面と係合し、摺接するテーパを有するカムフォロワが設けられた第２の枠部材とを備えて鏡筒装置を構成した。
【００１０】
上記構成によれば、第１の枠部材のカム溝の第１の斜面に対して、第２の枠部材のカムフォロワのテーパ面が摺接して移動されると、第１の枠部材と第２の枠部材は、相互間が相対的に移動する。そして、不用な外力が付与されると、該カムフォロワの大径部が第２の斜面に規制されて抜けが阻止される。これにより、不用な外力に対するカムフォロワの抜けが効果的に防止される。
【００１１】
また、この発明は、所定幅を有した底部を有し、互いに向き合いこの底部から周表面に向かって、その幅を広げるようにそれぞれ勾配を有した一対の第１の斜面と、この一対の第１の斜面の一方の面より連続して形成され、上記第１の斜面と異なる勾配を有した第２の斜面とからなるカム溝が設けられた枠部材を備えて鏡筒装置を構成した。
【００１２】
上記構成によれば、枠部材は、そのカム溝の第１の斜面に対して、略円錐台形状のカムフォロワのテーパ面が摺接して移動され、不用な外力が付与されると、該カムフォロワの大径部が第２の斜面に規制されて抜けが阻止される。これにより、不用な外力に対するカムフォロワの抜けが効果的に防止される。
【００１３】
【発明の実施の形態】
以下、この発明の実施の形態について、図面を参照して詳細に説明する。
【００１４】
図１は、この発明の一実施の形態に係る鏡筒装置を示すもので、第１及び第２の枠部材１０、１１は、例えばレンズ鏡筒を構成し、相互間が矢印Ａ、Ｂ方向（光軸方向）に直線移動自在に組付けられる。即ち、第１の枠部材１０の外周面には、この発明の特徴とするカム溝１２が３箇所、円周方向で１２０度等分で設けられる（図２参照）。そして、第２の枠部材１１の内周面には、円錐台形状のカムフォロワ１３が３個、上記カム溝１２に対応して１２０度等分で圧入されて配され、この第２の枠部材１１のカムフォロワ１３は、図２に示すように上記第１の枠部材１０のカム溝１１に挿入される。
【００１５】
上記カムフォロワ１３は、第２の枠部材１１に固定するための軸部１３ａと、カムフォロワ１３の第２の枠部材に対するスラスト方向（軸方向）の位置決めを行うための段部を設けるため、上記軸部１３ａと同軸に該軸部１３ａの直径よりやや径を大きくした直径を有した段軸部（基端部）１３ｂと、カムフォロワ先端部には、上記カム溝１２に係合、摺接する円錐台形状（テーパ）の部分１３ｃと、この円錐台形状（テーパ）の部分１３ｃの大径部１３ｄから径を減少するように上記段軸部１３ｂに向かって形成された円錐台形状（テーパ）の部分１３ｅとを有している。したがって、上記円錐台形状（テーパ）の部分１３ｅは、上記円錐台形状（テーパ）の部分１３ｃのテーパ角に対して逆テーパ角をなしている。なお、カムフォロワ１３の中心軸（中心線）は、カム溝１２の底部（カム底面）に対して垂線となっている。
【００１６】
上記構成により、例えば第１の枠１０が図示しない駆動機構によって回転されると、その回転に伴って、第２の枠部材１１のカムフォロワ１３が、第１の枠部材１０のカム溝１２に沿って摺動案内される。これにより、第２の枠部材１１は、第１の枠部材１０に対して光軸方向に直線移動される。
【００１７】
先ず、この発明の特徴とするカム溝１２を備える第１の枠部材１０の構成を説明するに先立ち、その成形方法について説明する。即ち、上記第１の枠部材１０は、例えばその１２０度の部分を成形する図３に示すスライド型１４が３組、リング状に組み合わされてモールド成形（射出成形）により、カム溝１２を含む外周面が成形される。
【００１８】
スライド型１４には、第１の枠部材１０の外周面に対応した凹状に湾曲した壁面１４１に突状のカム部１５が、上記カム溝１２に対応して設けられると共に、図示しないガイド部分や駆動部分等が設けられる。この３組のスライド型１４は、一つで第１の枠部材１０の１２０度の部分を形成し、３組で協働して第１の枠部材１０の外周全体を成形する。そして、この３組のスライド型１４は、その一つの型抜き方向が図２のＢＢ′を結ぶ方向とすると、他の二つの型抜き方向が上記ＢＢ′方向と１２０度の間隔を採った方向となる。
【００１９】
ここで、上記スライド型１４を３組用いて成形されるこの発明の特徴とする第１の枠部材１０のカム溝１２の構成について説明する。
【００２０】
即ち、第１の枠部材１０は、その外周面に３個のカム溝１２は、円周方向で略１２０度の間隔を有して設けられる。この３個のカム溝１２は、略同様に所定幅の底部（カム底面）１２１が、第２の枠部材１１の移動距離に応じた長さ寸法だけ形成され、この底部１２１の両側壁には、カムフォロワ１３の円錐台周壁のテーパの摺接される底部１２１から周表面（外周面）に向かって、その幅を広げるように勾配を有する一対の第１の斜面である第１の壁面１２２が設けられる。そして、この第１の壁面１２２の開口側には、連続して上記型抜き方向に略平行な第２の斜面である第２の壁面１２３が設けられる。なお、図４は、図１の第１の枠部材１０を上方より観た図を示し、図４中において、１０１は、スライド型１４同士の型合わせから生じるパーティングラインである。
【００２１】
上記第１の枠部材１０のカム溝１２の底部１２１、第１及び第２の壁面１２２、１２３は、上記スライド型１４に設けられる突状のカム部１５のカム先端面１５１、第１及び第２のカム面１５２、１５３により形成される。このうち、第２の壁面１２３は、その角度が、大きい方が型が抜きやすくなるが本発明の機能としては小さい方が効果が大きいので、型抜き方向に略平行な方向に対して抜き勾配を考慮して設定される。この抜き勾配としては、カムフォロワ１３の抜け防止を考慮しておおむね片側１度以上１０度以下に設定することが望ましい。
【００２２】
ここで、上記第１の枠部材１０のカム溝１２と第２の枠部材１１のカムフォロワ１３との詳細な配置構成について、図５及び図６を参照して説明する。この図５及び図６は、その図５が、上記図２の光軸とカムフォロワ１３の中心線を含む平面における付近の断面を示し、図６が、図５と同じカムフォロワ１３の位置でカムフォロワ１３の中心線を通りカム溝１２の中心線（カム溝の道筋）に垂直な断面を示す。
【００２３】
即ち、図５（ａ）（ｂ）（ｃ）は、それぞれ図２中におけるＡＡ′、ＢＢ′、ＣＣ′にカムフォロワ１３があるときの状態を示し、図６（ａ）（ｂ）（ｃ）それぞれは、カムフォロワ１３が図５（ａ）（ｂ）（ｃ）の同一位置にあるときのカムフォロワ１３の中心線を通りカム溝１２の中心線（カム道筋）に垂直な断面を示す。この図６（ａ）（ｂ）（ｃ）から明らかなように第１の壁面１２２は、カムフォロワ１３のテーパと略同じ開き角（テーパ角）θに設定され、第２の壁面１２３は、全長に亘って型抜き方向に対して所定の抜き勾配を有して略平行に設定される。
【００２４】
従って、カムフォロワ１３の中心線を通る断面の図６においては、スライド型１４の抜き方向とカムフォロワ１３の中心線とが一致した図６（ｂ）の断面では、第２の壁面１２３の両側の面が同じ抜き勾配程度の僅かな開き角になっているが、図６（ｂ）から離れるに従って一方の面が開きもう一方の面が閉じるように変化する。この例では図６（ｃ）の方が図６（ａ）よりも図６（ｂ）より離れているので変化も大きく、第２の壁面１２３の一方の面が第１の壁面１２２と略同じになり、第２の壁面１２３のもう一方の面が第１の壁面１２２よりもカム溝１２の内側に、つまりカムフォロワ１３の側に、その断面においてカムフォロワ１３の中心線に対し角度φだけ入り込む形になっている。
【００２５】
言い換えると、この第２の壁面１２３は、図６（ｃ）の位置に置いて、その一方側がカムフォロワ１３の基端部に対してカム溝１２の幅の内方向に向かって第１の壁面１２２とは異なる所定の勾配を有し、その他方側が幅の外方向に向かってわずかに第１の壁面とは異なる勾配を有する部分が存在する。このため、カムフォロワ１３は、第２の壁面１２３が内側に入り込んでいる部分を逃げるように基端側１３ｂがある。
【００２６】
このように第１の枠部材１０のカム溝１２は、その第２の壁面１２３の開き角がほとんどの部分において第１の壁面１２２の開き角よりも小さく設定されている。例えば、図５（ａ）（ｂ）、図６（ａ）（ｂ）で示す部分である。そのため、カムフォロワ１３は、レンズ鏡筒に対する不用な外力がかかってもカムフォロワ１３の大径部１３ｄとこの第２の壁面１２３のひっかかりあるため、この第２の壁面１２３のない場合よりも、カム溝１２から外れにくくなっている。そして、カムフォロワ１３と摺接するのが第１の壁面１２２のみであるため第２の壁面１２３の開き角が第１の壁面１２２と異なっても通常の作動に影響を及ぼさない。
【００２７】
このように、上記鏡筒装置は、第１の枠部材１０にカムフォロワ１３のテーパ１３ｃの摺接される第１の壁面１２２を形成し、この第１の壁面１２２に連続して型抜き方向と略平行な第２の壁面１２３を形成したカム溝１２を設けて、このカム溝１２に対して第２の枠部材１１のカムフォロワ１３のテーパが摺接するように係合させることにより、これら第１及び第２の枠部材１０、１１の相対移動を可能に組み合わせ配置するように構成した。これによれば、不用な外力が付与されても、カムフォロワ１３の大径部１３ｄが、カム溝１２の第２の壁面１２３に規制されて抜けが防止される。特に、カムフォロワ１３がカム溝１２の端部に近づけば近づくほど大径部１３ｄとカムフォロワ１３の中心線方向に対するいわゆるアンダーカット部分としての第２の壁面１２３のかかりは大きくなり抜け防止の効果は大きくなる。
【００２８】
また、この発明は、上記実施の形態に限ることなく、例えば図７乃至図１４に示すように第１の枠部材２０の内周面にカム溝２１を設けて、第２の枠部材２２の外周面にカムフォロワ２３を設け、第１の枠部材２０と第２の枠部材２２が相対移動する鏡筒構造においても適用可能で、同様の効果が期待される。
【００２９】
ここで、図７は、光軸方向から鏡筒装置を眺め、その破断した一部を示し、図８は、第１の枠部材２０を成形するのに用いるスライド型２４の斜視図を示し、図９は、光軸方向から眺めたスライド型２４の閉じた状態、即ち、成形部品（製品）を射出成形する状態を示し、図１０は、光軸方向から眺めたスライド型２４の開いた状態、即ち、成形部品（製品）の射出成形が完了し、成形型より成形部品を取り出すときの状態を示し、図１１は、第１の枠部材２０をスライド型２４の大スライド型２５の型抜き方向から見た状態を示し、図１２は、第１の枠部材２０をスライド型２４の小スライド型２６の型抜き方向から見た状態を示し、図１３は、光軸を含む平面で、かつ、この光軸中心に回転した平面の異なる位置でカム溝２１とカムフォロワ２３の断面の状態を示し、図１４は、カム溝２１に垂直な面の異なる位置で断面した状態を示す。
【００３０】
即ち、第１の枠部材２０の内周面には、この発明の特徴とするカム溝２１が３箇所、円周方向に１２０度等分で設けられる（図７参照）。そして、第２の枠部材２２の外周面には、円錐台形状の前述までのカムフォロワ１３と同形状のカムフォロワ２３が３個、上記カム溝２１に対応して円周方向に１２０度等分の位置で圧入されて配され、この第２の枠部材２２のカムフォロワ２３は、上記第１の枠部材２０のカム溝２１に挿入、係合する。これにより、例えば第１の枠部材２０が図示しない駆動機構によって回転されると、その回転に伴って、第２の枠部材２２のカムフォロワ２３が、第１の枠部材２０のカム溝２１に沿って摺接案内され、光軸方向に直線移動される。
【００３１】
上記カムフォロワ２３は、第２の枠部材２２に固定するための軸部２３ａと、このカムフォロワ２３の第２の枠部材２２に対するスラスト方向（軸方向）の位置決めを行うための段部を受けるため、この軸部２３ａの直径よりやや径を大きくした直径を有した段軸部（基端部）２３ｂと、このカムフォロワ先端部には、上記カム溝２３に係合、摺接する円錐台形状（テーパ）の部分２３ｃと、この円錐台形状（テーパ）の部分２３ｃの大径部２３ｄから径を減少するように上記軸部２３ａに向かって形成された円錐台形状（テーパ）の部分２３ｅとを有している。したがって、上記円錐台形状（テーパ）の部分２３ｅは、上記円錐台形状（テーパ）に部分２３ｃのテーパ角に対して逆テーパ角をなしている。なお、カムフォロワ２３の中心軸（中心線）は、カム溝２１の底部（カム底面）に対し、垂線となっている。
【００３２】
先ず、この発明の特徴とするカム溝２１を備える第１の枠部材２０の構成を説明するに先立ち、その成形方法について説明する。即ち、上記第１の枠部材２０は、例えばその外周の１２０度の部分に対応されるスライド型２４が３組、リング状に組み合わされてモールド成形（射出成形）により、この発明の特徴とする３個のカム溝２１を含む内周面が成形される。
【００３３】
このスライド型２４は、図８乃至図１０に示すようにそれぞれ３個の大スライド型２５と小スライド型２６で形成され、これら大及び小スライド型２５、２６の外周面には、第１の枠部材１０の内周面に対応した凸状に湾曲した壁面２５１、２６１及び突状のカム部２７、２８が設けられる。これら大及び小スライド型２５、２６の各壁面２５１、２６１及びカム部２７、２８は、協働して上記第１の枠部材２０の一つのカム溝２１を成形する。
【００３４】
そして、このスライド型２４は、３組が図８に示すように筒状に組み合わされて使用され、図９に示すように大及び小スライド型２５、２６がそれぞれ閉じられて第１の枠部材２０のモールド成形に供される。また、第１の枠部材２０の成形後、３組のスライド型２４は、図１０に示すように大及び小スライド型２５、２６の型抜きが順に行われ、即ち、小スライド型２６が初めに光軸中心（型中心）に向けて移動した後、大スライド型２５が光軸中心（型中心）に向けて移動して開かれて第１の枠部材２０は、これら大及び小スライド型２５、２６より取り外される。
【００３５】
即ち、上記スライド型２４には、図示しないガイド部分や駆動部分等が設けられ、その大及び小スライド型２５、２６が独立に放射方向（型抜き方向）に移動可能に設けられる。そして、筒状に組合わせられた３組のスライド型２４は、その一つの大スライド型２５の型抜き方向が、図７のＧＧ′を結ぶ方向とすると、その小スライド型２６の型抜き方向が、図７のＤＤ′を結ぶ方向となる。この場合、他の２組のスライド型２４の型抜き方向は、上記一つのスライド型２４の大スライド型２５、小スライド型２６の型抜き方向に対して第１の枠部材２０の円周方向にそれぞれ１２０度の方向となる。
【００３６】
ここで、上記スライド型２４を３組用いて成形されるこの発明の特徴とする第１の枠部材２０のカム構造（形状）について説明する。
【００３７】
即ち、第１の枠部材２０は、スライド型２４の大スライド型２５の型抜き方向（図１１参照）と、その小スライド型２６の型抜き方向（図１２参照）が異なる。そこで、カム溝２１は、３個とも同様に所定幅の底部（カム底面）２１１が、第２の枠部材２２の移動距離に応じた長さ寸法だけ形成される。このカム溝２１は、その底部（カム底面）２１１の両側壁にカムフォロワ２３のテーパ２３ｃの摺接される、底部から周表面（円周面２５１、２６１）に向かって、その幅を広げがるように勾配を有する一対の第１の斜面である第１の壁面２１２、２１４が設けられる。そして、この第１の壁面２１２、２１３には、大及び小スライド型２５、２６の型抜き方向に略平行な第２の斜面である第２の壁面２１３、２１５が設けられる。なお、図１１、図１２中において、２０１は、大及び小スライド型２５、２６との組み合わせから生ずるパーティングラインである。
【００３８】
上記第１の枠部材２０のカム溝２１の底部２１１、第１及び第２の壁面２１２、２１４及び２１３、２１５は、上記スライド型２４の大及び小スライド型２５、２６の各突状のカム部２７、２８のカム先端面２７１、２８１、第１及び第２のカム面２７２及び２８２、２７３及び２８３により形成される。このうち、第２の壁面２１３、２１５は、スライド型２５、２６の抜き勾配及びカムフォロワ２３の抜け防止を考慮して型抜き方向に対して、そのおおむね片側１度以上１０度以下と略平行に形成され、第３の壁面２１６を介して連続される。この第３の壁面２１６は、例えば小スライド型２６で形成されるが、大スライド型２５の移動軌跡の中に入っているために、その移動軌跡に対して抜き勾配を持って逃げる形状に形成され、第２のカム面２７３と連続した面となっている。
【００３９】
即ち、第１の枠部材２０のカム溝２１は、大スライド型２５のカム部２７の第１及び第２のカム面２７２、２７３で形成される第１及び第２の壁面２１２、２１３と小スライド型２６のカム部２８の第１及び第２のカム面２８２、２８３で形成される第１及び第２の壁面２１４、２１５で形成される。
【００４０】
上記カム溝２１の第１の壁面２１２、２１４は、カムフォロワ２３の先端の円錐面（テーパ面）と摺接する面であって、カムフォロワ２３の先端の円錐部（テーパ）が移動することによって作られる軌跡と略一致する面である。第２の壁面２１３、第３の壁部２１６は、大スライド型２５の型抜き方向に対して常に略一定の角度を持つ面であり、第２の壁面２１５は、小スライド型２６の型抜き方向に対して常に略一定の角度を持つ面である。この角度は、大きい方が型が抜きやすくなるが本発明の機能としては小さい方が効果が大きいので、抜き方向に略平行な方向に、おおむね片側１度以上１０度以下の抜き勾配に設定することが望ましい。
【００４１】
ここで、上記第１の枠部材２０のカム溝２１と第２の枠部材２２のカムフォロワ２３との詳細な配置構成について、図１３及び図１４を参照して説明する。この図１３及び図１４は、その図１３が、上記図７の光軸とカムフォロワ２３の中心線を含む平面における付近の断面を示し、図１４が、図１３と同じカムフォロワ２３の位置でカムフォロワ２３の中心線を通りカム溝２１の中心線に垂直な断面を示す。
【００４２】
図１３（ａ）（ｂ）（ｃ）（ｄ）（ｅ）は、それぞれ図７中におけるＤＤ′、ＥＥ′、ＦＦ′、ＧＧ′、ＨＨ′にカムフォロワ２３があるときの状態を示し、図１４（ａ）（ｂ）（ｃ）（ｄ）（ｅ）それぞれは、カムフロワ２３が図１３（ａ）（ｂ）（ｃ）（ｄ）（ｅ）の同一位置にあるときのカムフォロワ２３の中心線を通りカムの中心線（カム道筋）に垂直な断面を示す。ここで、Ｄの位置が前述したように小スライド型２６の型抜き方向、Ｇの位置が大スライド型２５の型抜き方向である。Ｅの位置が大スライド型２５と小スライド型２６のパーティングライン２０１付近であり、Ｆ及びＨの位置が大スライド型２５で形成されるカム溝２１の両端付近である。
【００４３】
この図１４（ａ）（ｂ）（ｃ）（ｄ）（ｅ）から明らかなようにカム溝２１の第１の壁面２１２、２１４は、カムフォロワ２３の先端のテーパと常に略同じ開き角に設定される。第２の壁面２１３は、大スライド型２５の型抜き方向に対して常に略一定の角度に設定されているため、カムフォロワ２３の中心線を通る図１４の断面では大スライド型２５の型抜き方向と一致した図１４（ｄ）の断面では両側の面が同じ開き角になっているが、図１４（ｄ）から離れるに従って一方の面が開きもう一方の面が閉じるように変化する。この例では図１４（ｃ）および図１４（ｅ）で第２の壁面２１３の一方の面の開き角は、第１の壁面２１２の開き角に近くなり、第２の壁面２１３の他方の面は第１の壁面２１２よりも内側にカムフォロワ２３の中心線方向に対するアンダーカット部分として入り込む形になっている。また、図１３（ｃ）（ｅ）についても同様である。
【００４４】
また、カム溝２１の第２の壁面２１５は、小スライド型２６の抜き方向に対して常に略一定の角度になっているため、カムフォロワ２３の中心線を通る図１４の断面において、小スライド型２６の型抜き方向と一致した図１４（ａ）で、両側の面が同じ開き角になっているが、図１４（ａ）から離れるに従って一方の面が開きもう一方の面が閉じるように変化する。小スライド型２６で形成している部分は、少ないため第２の壁面２１５の開き角の変化も大きくないが、パーティングライン２０１付近の図１４（ｂ）で、前述したように片側の面が大スライド型２５の移動軌跡を逃げるような第３の壁面２１６になっているため一方のカム面の開き角が第１の壁面２１４の開き角と略等しくなっている。なお、カムフォロワ２３は、第２の壁面２１５が内側に入り込んでいる部分を逃げるように基端側２３ｂがある。
【００４５】
このようにカム溝２１は、第２の壁面２１３、２１５、第３の壁面２１６の開き角がほとんどの部分において、第１の壁面２１２、２１４の開き角よりも小さくなっている。そのため、カムフォロワ２３は、レンズ鏡筒に対する不用意（不用）な外力がかかってもカムフォロワ２３の大径部２３ｄとこの第２の壁面２１３、２１５とのひっかかりがあるため、この第２の壁面２１３、２１５がない場合よりも、カム溝２１から外れにくくなっている。また、このカム溝２１は、カムフォロワ２３と摺接している部分が第１の壁面２１２、２１４のみであるため、第２の壁面２１３、２１５、第３の壁面２１６の開き角が第１の壁面２１２、２１４と異なっても通常の作動に影響を及ぼすことなく、同様に良好なカム駆動が実現される。
【００４６】
なお、上記各実施の形態では、第１の枠部材１０、２０を回転駆動して、第２の枠部材１１、２２を光軸方向に直線移動させる鏡筒構造に適用した場合で説明したが、これに限ることなく、第２の枠部材１１、２２を回転駆動して第１の枠部材１０、２０を直線移動させるように構成することも可能である。そして、鏡筒構造としては、その他、二段鏡筒構造に限ることなく、各種の構成のものにおいても適用可能である。
【００４７】
また、上記各実施の形態においては、成形方法として、スライド型の型抜き方向に対して一定の角度を持つ面を両側とも同じ角度としたが、必ずしも同じ角度にする必要はない。また、上記実施の形態例では、組み立て時のみに使い実使用では使わない部分やカム溝の終端についても二つの壁面で構成したが、それらは他の形状でもかまわないことは、勿論のことである。
【００４８】
さらに、上記実施の形態では、カム溝を１２０度等分で設けるようにした枠部材を用いるように構成した場合で説明したが、これに限ることなく、カム溝の本数は３本でなくてもよいし、等間隔でなてもよい。また、一つのスライド型で複数のカム溝を形成するように構成することも可能である。
【００４９】
よって、この発明は、上記各実施の形態に限ることなく、その他、実施段階ではその要旨を逸脱しない範囲で種々の変形を実施し得ることが可能である。さらに、上記各実施形態には、種々の段階の発明が含まれており、開示される複数の構成要件における適宜な組合せにより種々の発明が抽出され得る。
【００５０】
例えば各実施形態に示される全構成要件から幾つかの構成要件が削除されても、発明が解決しようとする課題の欄で述べた課題が解決でき、発明の効果で述べられている効果が得られる場合には、この構成要件が削除された構成が発明として抽出され得る。
【００５１】
また、上述した実施の形態に基づいて
（１）　カム底面より、幅を広げる方向に傾斜した一対の第１の壁面と、この一対の第１の壁面より型抜き方向と略平行に延出される第２の壁面とが設けられたカム溝を形成した枠部材
を具備することを特徴とする鏡筒装置を提供することができる。
【００５２】
（２）　カム底面より、幅を広げる方向に傾斜した一対の第１の壁面と、この一対の第１の壁面より型抜き方向と略平行に延出される第２の壁面とが設けられたカム溝を形成した第１の枠部材と、
上記第１の壁面に係合して摺接されるテーパを上記カム溝に対向して設けられた第２の枠部材と
を具備することを特徴とする鏡筒装置を提供することができる。
【００５３】
【発明の効果】
以上詳述したように、この発明によれば、簡易な構成で、レンズ鏡筒に不用な外力がかかってもカムフォロワの抜け防止を図り得るようにした鏡筒装置を提供することができる。
【図面の簡単な説明】
【図１】この発明の一実施の形態に係る鏡筒装置の構成を示した分解斜視図である。
【図２】図１の第１及び第２の枠部材を光軸方向に直線移動自在に組付けた状態を示した正面図である。
【図３】図１の第１の枠部材を成形するのに用いる複数のスライド型の１つを取り出した斜視図である。
【図４】図１の第１の枠部材をスライド型の型抜き方向から示した平面図である。
【図５】図２を光軸を通る異なる面で断面した状態のカムフォロワとカム溝の関係を示した断面図である。
【図６】図５の各断面位置であって、カムフォロワの中心線と通り、且つカム溝の中心線に垂直に断面した状態を示した断面図である。
【図７】この発明の他の実施の形態に係る鏡筒装置の一部を破断した状態を示した正面図である。
【図８】図７の第１の枠部材を成形するのに用いられるスライド型を示した斜視図である。
【図９】図８のスライド型の閉じた状態を正面から示した平面図である。
【図１０】図９のスライド型の開いた状態を正面から示した平面図である。
【図１１】図７の第１の枠部材をスライド型の大スライド型の型抜き方向から示した一部断面図である。
【図１２】図７の第１の枠部材をスライド型の小スライド型の型抜き方向から示した一部断面図である。
【図１３】図７を光軸を通る異なる面で断面した状態のカムフォロワとカム溝の関係を示した断面図である。
【図１４】図１３の各断面位置であって、カムフォロワの中心線と通り、且つカム溝の中心線に垂直に断面した状態を示した断面図である。
【符号の説明】
１０　…　第１の枠部材
１０１　…　パーティングライン
１１　…　第２の枠部材
１２　…　カム溝
１２１　…　底部
１２２　…　第１の壁面
１２３　…　第２の壁面
１３　…　カムフォロワ
１４　…　スライド型
１４１　…　壁面
１５　…　カム部
１５１　…　カム先端面
１５２　…　第１のカム面
１５３　…　第２のカム面
２０　…　第１の枠部材
２０１　…　パーティングライン
２１　…　カム溝
２１１　…　底部
２１２、２１４　…　第１の壁部
２１３、２１５　…　第２の壁面
２１６　…　第３の壁面
２２　…　第２の枠部材
２３　…　カムフォロワ
２４　…　スライド型
２５　…　大スライド型
２５１　…　壁面
２６　…　小スライド型
２６１　…　壁面
２７　…　第１のカム部
２７１　…　カム先端面
２７２　…　第１のカム面
２７３　…　第２のカム面
２８　…　第２のカム部
２８１　…　カム先端面
２８２　…　第１のカム面
２８３　…　第２のカム面[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lens barrel device having a frame member that can move linearly, for example.
[0002]
[Prior art]
In this type of lens barrel device, as a means for controlling the linear movement of the cylindrical frame member, a cam groove oblique to the optical axis is formed in the frame member, and a cam follower is slidable with respect to this cam groove. By engaging and disposing, the frame member is configured to move linearly. In a lens barrel device using this cam groove, the frame member is molded using a molding die, thereby making it possible to manufacture the lens at low cost.
[0003]
By the way, in such a lens barrel device, when forming the cam groove of the frame member, taking into account the die extraction work of extracting the projection of the molding die from the cam groove of the frame member, By forming the opening side to be inclined by a predetermined angle so as not to be under, the die can be cut from the product.
[0004]
For this reason, in an assembled state in which the cam follower is slidably inserted into the cam groove of the frame member, if an inadvertent (unnecessary) external force such as impact or drop is applied, the cam follower comes out of the cam groove. There is a problem that it is lost.
[0005]
[Problems to be solved by the invention]
As described above, the conventional lens barrel device has a problem that the cam follower may fall out of the cam groove.
[0006]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a lens barrel device having a simple configuration and capable of preventing a cam follower from coming off.
[0007]
[Means for Solving the Problems]
The present invention has a pair of first slopes each having a bottom having a predetermined width, facing each other, and extending from the bottom toward the peripheral surface, and having a slope so as to increase the width, and a pair of first slopes. The lens barrel device was provided with a frame member provided with a cam groove defined by a second slope that is formed continuously from one surface and has a slope inward of the width.
[0008]
According to the above configuration, the frame member is moved by the tapered surface of the substantially frustoconical cam follower slidably in contact with the first slope of the cam groove, and when an unnecessary external force is applied, the size of the cam follower increases. The diameter is restricted by the second slope to prevent the falling off. This effectively prevents the cam follower from coming off due to unnecessary external force.
[0009]
In addition, the present invention has a pair of first slopes having bottoms having a predetermined width, facing each other, and each having a slope so as to increase the width from the bottom to the peripheral surface, and a pair of the first slopes. A first frame member provided with a cam groove which is formed continuously from one of the slopes and has a second slope having a slope inward of the width, and a cam groove having a maximum diameter of the cam groove. A second frame member provided with a cam follower having a tapered cam follower which is positioned inside and is in engagement with the first inclined surface and slidably comes into contact therewith.
[0010]
According to the above configuration, when the tapered surface of the cam follower of the second frame member slides against the first inclined surface of the cam groove of the first frame member and moves, the first frame member and the second frame member are moved. Are relatively moved between each other. When an unnecessary external force is applied, the large-diameter portion of the cam follower is restricted by the second inclined surface, and the cam follower is prevented from coming off. This effectively prevents the cam follower from coming off due to unnecessary external force.
[0011]
Further, the present invention has a pair of first slopes having bottoms having a predetermined width, facing each other, and extending from the bottom toward the peripheral surface, and having a slope so as to increase the width, and a pair of first slopes. The lens barrel device is provided with a frame member provided with a cam groove formed continuously from one surface of the first slope and a second slope having a different slope from the first slope.
[0012]
According to the above configuration, the frame member is moved by the tapered surface of the substantially frustoconical cam follower slidably contacting the first slope of the cam groove, and when an unnecessary external force is applied, the cam follower is moved. The large-diameter portion is restricted by the second slope to prevent the large diameter portion from coming off. This effectively prevents the cam follower from coming off due to unnecessary external force.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
FIG. 1 shows a lens barrel device according to an embodiment of the present invention, in which first and second frame members 10 and 11 constitute, for example, a lens barrel, and the distance between the first and second frame members 10 and 11 is in the directions of arrows A and B. It is assembled so that it can move linearly (in the direction of the optical axis). That is, on the outer peripheral surface of the first frame member 10, three cam grooves 12, which are features of the present invention, are provided at equal intervals of 120 degrees in the circumferential direction (see FIG. 2). On the inner peripheral surface of the second frame member 11, three frustum-shaped cam followers 13 are press-fitted at equal intervals of 120 degrees corresponding to the cam grooves 12, and are arranged. The cam follower 11 is inserted into the cam groove 11 of the first frame member 10 as shown in FIG.
[0015]
The cam follower 13 has a shaft portion 13a for fixing the cam follower 13 to the second frame member 11 and a step portion for positioning the cam follower 13 in the thrust direction (axial direction) with respect to the second frame member. A stepped shaft portion (base end portion) 13b having a diameter slightly larger than the diameter of the shaft portion 13a coaxially with the portion 13a, and a truncated cone that engages with and slides on the cam groove 12 at a tip portion of the cam follower. A portion 13c having a shape (taper) and a portion having a truncated cone (taper) formed toward the stepped shaft portion 13b so as to decrease in diameter from the large diameter portion 13d of the portion 13c having the truncated cone shape (taper). 13e. Therefore, the truncated cone-shaped (tapered) portion 13e forms an inverse taper angle with respect to the taper angle of the truncated-cone-shaped (tapered) portion 13c. The center axis (center line) of the cam follower 13 is perpendicular to the bottom of the cam groove 12 (cam bottom surface).
[0016]
With the above configuration, for example, when the first frame 10 is rotated by a driving mechanism (not shown), the cam follower 13 of the second frame member 11 moves along the cam groove 12 of the first frame member 10 with the rotation. Sliding guide. Thereby, the second frame member 11 is linearly moved in the optical axis direction with respect to the first frame member 10.
[0017]
First, prior to describing the configuration of the first frame member 10 having the cam groove 12 which is a feature of the present invention, a molding method thereof will be described. That is, the first frame member 10 includes the cam grooves 12 by molding (injection molding) by combining three sets of the slide dies 14 shown in FIG. An outer peripheral surface is formed.
[0018]
The slide die 14 is provided with a cam portion 15 protruding from a concavely curved wall surface 141 corresponding to the outer peripheral surface of the first frame member 10 in correspondence with the cam groove 12. A driving part and the like are provided. The three sets of slide dies 14 form a 120-degree portion of the first frame member 10 together, and the three sets cooperate to form the entire outer periphery of the first frame member 10. The three sets of slide dies 14 are arranged such that one die-cutting direction is a direction connecting BB 'in FIG. 2 and the other two die-cutting directions are spaced at 120 degrees from the BB' direction. It becomes.
[0019]
Here, the configuration of the cam groove 12 of the first frame member 10 which is a feature of the present invention formed by using three sets of the slide dies 14 will be described.
[0020]
That is, in the first frame member 10, three cam grooves 12 are provided on the outer peripheral surface thereof at intervals of about 120 degrees in the circumferential direction. Each of the three cam grooves 12 has a bottom portion (cam bottom surface) 121 having a predetermined width substantially the same length as the moving distance of the second frame member 11. A first wall surface 122, which is a pair of first slopes, having a gradient so as to increase its width from the bottom 121 of the cam follower 13, which is in sliding contact with the taper of the peripheral wall of the truncated cone, toward the peripheral surface (outer peripheral surface). Provided. On the opening side of the first wall surface 122, a second wall surface 123 which is a second inclined surface substantially parallel to the die-cutting direction is provided continuously. FIG. 4 is a view of the first frame member 10 of FIG. 1 as viewed from above. In FIG. 4, reference numeral 101 denotes a parting line resulting from the matching of the slide dies 14.
[0021]
The bottom 121, the first and second wall surfaces 122, 123 of the cam groove 12 of the first frame member 10 are the cam tip surface 151, the first, and the second of the projecting cam portion 15 provided on the slide die 14. The two cam surfaces 152 and 153 are formed. Among them, the larger the angle of the second wall surface 123 is, the easier it is to remove the mold, but the smaller the angle, the greater the effect of the present invention. It is set in consideration of. It is desirable that the draft is set to be approximately 1 degree or more and 10 degrees or less on one side in consideration of prevention of the cam follower 13 from coming off.
[0022]
Here, a detailed arrangement of the cam groove 12 of the first frame member 10 and the cam follower 13 of the second frame member 11 will be described with reference to FIGS. 5 and 6 show a cross section near a plane including the optical axis of FIG. 2 and the center line of the cam follower 13, and FIG. 6 shows the cam follower 13 at the same position of the cam follower 13 as in FIG. 3 shows a cross section passing through the center line of FIG. 5 and perpendicular to the center line of the cam groove 12 (path of the cam groove).
[0023]
That is, FIGS. 5A, 5B, and 5C show the states when the cam followers 13 are provided at AA ', BB', and CC 'in FIG. 2, respectively, and FIGS. 6A, 6B, and 6C. Each shows a cross section perpendicular to the center line (cam path) of the cam groove 12 passing through the center line of the cam follower 13 when the cam follower 13 is at the same position in FIGS. 5 (a), 5 (b) and 5 (c). As is clear from FIGS. 6A, 6B, and 6C, the first wall surface 122 has an opening angle (taper angle) θ substantially equal to the taper of the cam follower 13, and the second wall surface 123 has a total length. Are set substantially parallel to each other with a predetermined draft angle with respect to the die removing direction.
[0024]
Accordingly, in FIG. 6 of a cross section passing through the center line of the cam follower 13, in the cross section of FIG. 6B in which the pulling direction of the slide die 14 and the center line of the cam follower 13 match, both surfaces of the second wall surface 123 are provided. Has a slight opening angle of the same draft angle, but changes so that one surface opens and the other surface closes as the distance from FIG. 6B increases. In this example, FIG. 6 (c) is farther away from FIG. 6 (b) than FIG. 6 (b), so that the change is large, and one surface of the second wall surface 123 is substantially the same as the first wall surface 122. And the other surface of the second wall surface 123 is inserted into the cam groove 12 more than the first wall surface 122, that is, on the side of the cam follower 13 by an angle φ with respect to the center line of the cam follower 13 in the cross section. It has become.
[0025]
In other words, the second wall surface 123 is placed at the position shown in FIG. 6C, and one side of the second wall surface 123 faces the base end of the cam follower 13 toward the inside of the width of the cam groove 12. There is a portion having a predetermined slope different from that of the first wall surface, and the other side has a slope slightly different from the first wall surface toward the outside of the width. For this reason, the cam follower 13 has a base end side 13b so as to escape a portion where the second wall surface 123 enters inside.
[0026]
As described above, in the cam groove 12 of the first frame member 10, the opening angle of the second wall surface 123 is set to be smaller than the opening angle of the first wall surface 122 in most portions. For example, the portions shown in FIGS. 5A and 5B and FIGS. 6A and 6B. Therefore, even if an unnecessary external force is applied to the lens barrel, the cam follower 13 is caught by the large diameter portion 13d of the cam follower 13 and the second wall surface 123. 12 is hard to come off. Since only the first wall surface 122 is in sliding contact with the cam follower 13, even if the opening angle of the second wall surface 123 is different from that of the first wall surface 122, normal operation is not affected.
[0027]
As described above, the lens barrel device forms the first wall surface 122 on which the taper 13c of the cam follower 13 is slidably contacted with the first frame member 10, and the first wall surface 122 is continuously connected to the die removing direction. A cam groove 12 having a substantially parallel second wall surface 123 is provided, and the cam groove 12 is engaged with the cam groove 12 such that the taper of the cam follower 13 of the second frame member 11 comes into sliding contact with the cam groove 12. And the second frame members 10 and 11 are arranged so as to be capable of relative movement. According to this, even if an unnecessary external force is applied, the large-diameter portion 13 d of the cam follower 13 is restricted by the second wall surface 123 of the cam groove 12 and is prevented from coming off. In particular, the closer the cam follower 13 is to the end of the cam groove 12, the greater the engagement between the large diameter portion 13 d and the second wall surface 123 as a so-called undercut portion with respect to the center line direction of the cam follower 13. Become.
[0028]
In addition, the present invention is not limited to the above-described embodiment. For example, as shown in FIGS. 7 to 14, the cam groove 21 is provided on the inner peripheral surface of the first frame member 20 so that the second frame member 22 A cam follower 23 is provided on the outer peripheral surface, and the present invention can be applied to a lens barrel structure in which the first frame member 20 and the second frame member 22 relatively move, and similar effects are expected.
[0029]
Here, FIG. 7 is a view of the lens barrel device viewed from the optical axis direction, and shows a broken part thereof. FIG. 8 is a perspective view of a slide mold 24 used to mold the first frame member 20, FIG. 9 shows the closed state of the slide mold 24 as viewed from the optical axis direction, that is, the state of injection molding of a molded part (product). FIG. 10 shows the opened state of the slide mold 24 as viewed from the optical axis direction. That is, FIG. 11 shows a state in which the injection molding of the molded part (product) is completed and the molded part is taken out from the molding die. FIG. 12 shows a state in which the first frame member 20 is viewed from a direction in which the small slide die 26 of the slide die 24 is removed, and FIG. 13 shows a state including the optical axis, and FIG. And the cam groove 21 and the cam groove at different positions on the plane rotated about the optical axis. Shows the state of the cross-section of the follower 23, Figure 14 shows a state in which the cross-section at different locations a plane perpendicular to the cam groove 21.
[0030]
That is, the cam groove 21 which is a feature of the present invention is provided on the inner peripheral surface of the first frame member 20 at three places at equal intervals in the circumferential direction at 120 degrees (see FIG. 7). On the outer peripheral surface of the second frame member 22, there are three cam followers 23 having the same shape as the above-described cam followers 13 having a truncated cone shape and corresponding to the above-mentioned cam grooves 21 in the circumferential direction at equal intervals of 120 degrees. The cam follower 23 of the second frame member 22 is inserted into and engaged with the cam groove 21 of the first frame member 20. Accordingly, for example, when the first frame member 20 is rotated by a drive mechanism (not shown), the cam follower 23 of the second frame member 22 moves along the cam groove 21 of the first frame member 20 with the rotation. And is linearly moved in the optical axis direction.
[0031]
The cam follower 23 receives a shaft portion 23a for fixing to the second frame member 22 and a step portion for positioning the cam follower 23 in the thrust direction (axial direction) with respect to the second frame member 22. A stepped shaft portion (base end portion) 23b having a diameter slightly larger than the diameter of the shaft portion 23a and a front end portion of the cam follower have a truncated cone shape (taper) which engages with and slides on the cam groove 23. And a frustoconical (tapered) portion 23e formed toward the shaft portion 23a so as to decrease in diameter from the large diameter portion 23d of the frustoconical (tapered) portion 23c. ing. Therefore, the frusto-conical shape (taper) 23e has an inverse taper angle with respect to the taper angle of the portion 23c in the frusto-conical shape (taper). The center axis (center line) of the cam follower 23 is perpendicular to the bottom of the cam groove 21 (cam bottom surface).
[0032]
First, prior to describing the configuration of the first frame member 20 including the cam groove 21 which is a feature of the present invention, a molding method thereof will be described. That is, the first frame member 20 is a feature of the present invention by, for example, molding (injection molding) three sets of slide dies 24 corresponding to a 120-degree portion on the outer periphery thereof, which are combined in a ring shape. An inner peripheral surface including the three cam grooves 21 is formed.
[0033]
The slide mold 24 is formed of three large slide molds 25 and three small slide molds 26 as shown in FIGS. 8 to 10, respectively. The convexly curved wall surfaces 251 and 261 corresponding to the inner peripheral surface of the frame member 10 and the protruding cam portions 27 and 28 are provided. The wall surfaces 251 and 261 and the cam portions 27 and 28 of the large and small slide dies 25 and 26 cooperate to form one cam groove 21 of the first frame member 20.
[0034]
As shown in FIG. 8, three sets of the slide dies 24 are used in a cylindrical shape, and the large and small slide dies 25 and 26 are closed as shown in FIG. 20. After the first frame member 20 has been formed, the three sets of slide dies 24 are sequentially die-cut from the large and small slide dies 25 and 26 as shown in FIG. After moving toward the center of the optical axis (center of the mold), the large slide mold 25 moves toward the center of the optical axis (center of the mold) and is opened, so that the first frame member 20 is opened by the large and small slide molds. Removed from 25 and 26.
[0035]
That is, the slide die 24 is provided with a guide portion, a drive portion, and the like (not shown), and the large and small slide dies 25 and 26 are provided so as to be independently movable in the radial direction (die-cutting direction). The three sets of slide dies 24 combined in a cylindrical shape are different from each other in that the direction in which one of the large slide dies 25 is removed is the direction connecting GG 'in FIG. Is the direction connecting DD ′ in FIG. In this case, the other two sets of slide dies 24 are removed in the circumferential direction of the first frame member 20 with respect to the large slide dies 25 and the small slide dies 26 of the one slide mold 24. , Respectively.
[0036]
Here, a description will be given of the cam structure (shape) of the first frame member 20, which is a feature of the present invention, formed by using three sets of the slide dies 24.
[0037]
That is, in the first frame member 20, the direction in which the large slide die 25 of the slide die 24 is released (see FIG. 11) and the direction in which the small slide die 26 is released (see FIG. 12) are different. Therefore, the bottoms (cam bottoms) 211 of the predetermined width are formed in the three cam grooves 21 by the length dimension corresponding to the moving distance of the second frame member 22. The cam groove 21 is slidably contacted with the taper 23c of the cam follower 23 on both side walls of the bottom portion (cam bottom surface) 211. The width of the cam groove 21 increases from the bottom portion to the peripheral surface (circumferential surfaces 251 and 261). The first wall surfaces 212 and 214, which are a pair of first inclined surfaces having a gradient as described above, are provided. The first wall surfaces 212 and 213 are provided with second wall surfaces 213 and 215, which are second inclined surfaces substantially parallel to the direction in which the large and small slide dies 25 and 26 are removed. In FIGS. 11 and 12, reference numeral 201 denotes a parting line generated by a combination with the large and small slide dies 25 and 26.
[0038]
The bottom portion 211 of the cam groove 21 and the first and second wall surfaces 212, 214 and 213, 215 of the first frame member 20 are respectively formed by the projecting cams of the large and small slide molds 25, 26 of the slide mold 24. The first and second cam surfaces 272, 282, 273 and 283 are formed by the cam tip surfaces 271 and 281 of the portions 27 and 28. Of these, the second wall surfaces 213 and 215 are substantially parallel to the die-cutting direction at approximately 1 degree or more and 10 degrees or less with respect to the die-cutting direction in consideration of the draft angle of the slide dies 25 and 26 and prevention of the cam follower 23 from coming off. It is formed and is continued through the third wall surface 216. The third wall surface 216 is formed by, for example, a small slide mold 26, but is formed in a shape that escapes with a draft with respect to the movement locus because it is included in the movement locus of the large slide mold 25. The second cam surface 273 is continuous.
[0039]
That is, the cam groove 21 of the first frame member 20 is smaller than the first and second wall surfaces 212 and 213 formed by the first and second cam surfaces 272 and 273 of the cam portion 27 of the large slide die 25. The slide portion 26 is formed by first and second wall surfaces 214 and 215 formed by the first and second cam surfaces 282 and 283 of the cam portion 28.
[0040]
The first wall surfaces 212 and 214 of the cam groove 21 are surfaces that are in sliding contact with the conical surface (taper surface) at the tip of the cam follower 23, and are formed by the movement of the conical portion (taper) at the tip of the cam follower 23. This is a surface that substantially matches the trajectory. The second wall surface 213 and the third wall portion 216 are surfaces having a substantially constant angle with respect to the direction in which the large slide die 25 is released. The surface always has a substantially constant angle with respect to the direction. The larger the angle, the easier the mold is to be removed, but the smaller the function of the present invention, the greater the effect. Therefore, the draft is set in a direction substantially parallel to the drawing direction, with a draft of 1 degree or more and 10 degrees or less on one side. It is desirable.
[0041]
Here, the detailed arrangement of the cam groove 21 of the first frame member 20 and the cam follower 23 of the second frame member 22 will be described with reference to FIGS. 13 and FIG. 14 show a cross section near a plane including the optical axis of FIG. 7 and the center line of the cam follower 23, and FIG. 14 shows the cam follower 23 at the same position of the cam follower 23 as in FIG. 3 shows a cross section passing through the center line of FIG.
[0042]
FIGS. 13 (a), (b), (c), (d), and (e) show states when the cam follower 23 is located at DD ', EE', FF ', GG', and HH 'in FIG. 7, respectively. 14 (a), (b), (c), (d), and (e) indicate the center of the cam follower 23 when the cam follower 23 is located at the same position in FIGS. 13 (a), (b), (c), (d), and (e). A cross-section through the line and perpendicular to the cam center line (cam path) is shown. Here, the position of D is the direction in which the small slide die 26 is released as described above, and the position of G is the direction in which the large slide die 25 is released. The position E is near the parting line 201 of the large slide mold 25 and the small slide mold 26, and the positions F and H are near both ends of the cam groove 21 formed by the large slide mold 25.
[0043]
14 (a), (b), (c), (d), and (e), the first wall surfaces 212 and 214 of the cam groove 21 are always set to have substantially the same opening angle as the taper at the tip of the cam follower 23. Is done. Since the second wall surface 213 is always set at a substantially constant angle with respect to the direction in which the large slide die 25 is released, the direction in which the large slide die 25 is released in the cross section of FIG. 14 passing through the center line of the cam follower 23. In the cross section of FIG. 14 (d) which coincides with FIG. 14 (d), both sides have the same opening angle, but as the distance from FIG. 14 (d) increases, one side opens and the other side closes. In this example, the opening angle of one surface of the second wall surface 213 in FIGS. 14C and 14E is close to the opening angle of the first wall surface 212, and the other surface of the second wall surface 213 Is formed inside the first wall surface 212 as an undercut portion with respect to the center line direction of the cam follower 23. The same applies to FIGS. 13C and 13E.
[0044]
Further, since the second wall surface 215 of the cam groove 21 is always at a substantially constant angle with respect to the pulling-out direction of the small slide die 26, the small slide die 215 in the cross section of FIG. In FIG. 14 (a), which coincides with the die-cutting direction of 26, both sides have the same opening angle, but as the distance from FIG. 14 (a) increases, one side opens and the other side closes. I do. Since the portion formed by the small slide mold 26 is small, the change in the opening angle of the second wall surface 215 is not large, but as shown in FIG. Since the third wall 216 escapes the locus of movement of the large slide die 25, the opening angle of one cam surface is substantially equal to the opening angle of the first wall 214. The cam follower 23 has a proximal end 23b so as to escape a portion where the second wall surface 215 has entered.
[0045]
As described above, in the cam groove 21, the opening angles of the second wall surfaces 213 and 215 and the third wall surface 216 are almost smaller than the opening angles of the first wall surfaces 212 and 214. Therefore, the cam follower 23 is caught between the large-diameter portion 23d of the cam follower 23 and the second wall surfaces 213 and 215 even if careless (unnecessary) external force is applied to the lens barrel. , 215 are less likely to come off from the cam groove 21 than when no cam groove 21 is provided. Since the cam groove 21 has only the first wall surfaces 212 and 214 in sliding contact with the cam follower 23, the opening angles of the second wall surfaces 213 and 215 and the third wall surface 216 are the first wall surfaces. Even better than 212 and 214, normal cam operation is not affected and a similarly good cam drive is achieved.
[0046]
In each of the above embodiments, the case where the first frame members 10 and 20 are driven to rotate and the second frame members 11 and 22 are linearly moved in the optical axis direction is applied to a lens barrel structure. However, the present invention is not limited to this, and the first frame members 10 and 20 may be configured to linearly move by rotating the second frame members 11 and 22. The lens barrel structure is not limited to the two-stage lens barrel structure, and can be applied to various structures.
[0047]
Further, in each of the above-described embodiments, as a molding method, the surfaces having a certain angle with respect to the direction in which the slide die is removed have the same angle on both sides, but it is not always necessary to make the same angle. Further, in the above-described embodiment, the two wall surfaces are also used for the part that is used only during the assembling and is not used for actual use or the end of the cam groove, but they may be of other shapes. is there.
[0048]
Further, in the above-described embodiment, the case has been described in which the frame member is provided so that the cam grooves are provided at equal intervals of 120 degrees. However, the present invention is not limited to this, and the number of the cam grooves is not three. Or at regular intervals. Further, it is also possible to configure so that a plurality of cam grooves are formed by one slide type.
[0049]
Therefore, the present invention is not limited to the above embodiments, and various other modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.
[0050]
For example, even if some components are deleted from all the components shown in each embodiment, the problem described in the section of the problem to be solved by the invention can be solved, and the effects described in the effects of the invention can be obtained. In this case, a configuration from which this configuration requirement is deleted can be extracted as an invention.
[0051]
Also, based on the above-described embodiment,
(1) A cam provided with a pair of first wall surfaces that are inclined from the cam bottom surface in a direction of increasing the width, and a second wall surface that extends from the pair of first wall surfaces substantially in parallel with the die-cutting direction. Frame member with groove
Can be provided.
[0052]
(2) A cam provided with a pair of first wall surfaces that are inclined from the cam bottom surface in a direction of increasing the width, and a second wall surface that extends from the pair of first wall surfaces substantially in parallel with the die-cutting direction. A first frame member having a groove,
A second frame member provided with a taper which is slidably engaged with the first wall surface and opposed to the cam groove;
Can be provided.
[0053]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a lens barrel device that can prevent the cam follower from coming off even when an unnecessary external force is applied to the lens barrel with a simple configuration.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a configuration of a lens barrel device according to an embodiment of the present invention.
FIG. 2 is a front view showing a state where the first and second frame members of FIG. 1 are assembled so as to be linearly movable in an optical axis direction.
FIG. 3 is a perspective view of one of a plurality of slide dies used to mold the first frame member of FIG. 1;
FIG. 4 is a plan view showing the first frame member of FIG. 1 as viewed from a direction in which a slide die is removed.
FIG. 5 is a cross-sectional view showing a relationship between a cam follower and a cam groove in a state where FIG. 2 is cross-sectionally taken along different planes passing through the optical axis.
FIG. 6 is a cross-sectional view showing a cross-section at each cross-sectional position in FIG. 5 and passing through the center line of the cam follower and perpendicular to the center line of the cam groove.
FIG. 7 is a front view showing a state where a part of a lens barrel device according to another embodiment of the present invention is broken.
FIG. 8 is a perspective view showing a slide mold used to mold the first frame member of FIG. 7;
9 is a plan view showing the closed state of the slide type shown in FIG. 8 from the front.
FIG. 10 is a plan view showing the opened state of the slide type of FIG. 9 from the front.
FIG. 11 is a partial cross-sectional view showing the first frame member of FIG. 7 in a slide type large slide type from a die-cutting direction.
FIG. 12 is a partial cross-sectional view showing the first frame member of FIG. 7 as viewed from the direction in which the slide type small slide die is removed;
FIG. 13 is a cross-sectional view showing the relationship between the cam follower and the cam groove in a state where FIG. 7 is cross-sectionally taken along different planes passing through the optical axis.
14 is a cross-sectional view showing each cross-sectional position of FIG. 13, which crosses the center line of the cam follower and is perpendicular to the center line of the cam groove.
[Explanation of symbols]
10 First frame member
101 ... parting line
11 Second frame member
12… cam groove
121… bottom
122 ... First wall
123… Second wall
13 ... Cam Follower
14… slide type
141… wall
15… cam part
151… Cam tip surface
152... First cam surface
153: second cam surface
20... First frame member
201… parting line
21… cam groove
211… bottom
212, 214 ... 1st wall part
213, 215 ... second wall surface
216… Third wall
22... Second frame member
23… Cam Follower
24… slide type
25… large slide type
251… wall
26… small slide type
261… wall
27 ... first cam part
271… Cam tip surface
272: first cam surface
273: second cam surface
28 ... second cam part
281… Cam tip surface
282: first cam surface
283: second cam surface

Claims

A pair of first slopes each having a bottom having a predetermined width, facing each other, and extending from the bottom toward the peripheral surface, and having a slope so as to increase the width, and one of the pair of first slopes A lens barrel device comprising: a frame member provided with a cam groove which is formed continuously and has a second slope having a slope inward of the width.

2. The lens barrel device according to claim 1, wherein the second slope is provided substantially parallel to a direction in which a die for forming the cam groove is removed.

3. The lens barrel device according to claim 1, wherein the frame member is provided with a cam groove on an outer peripheral surface.

3. The lens barrel device according to claim 1, wherein a cam groove is provided on an inner peripheral surface of the frame member.

A pair of first slopes having bottoms of a predetermined width, facing each other, and each having a gradient from the bottom to the peripheral surface so as to increase the width, and one of the pair of first slopes A first frame member provided with a cam groove formed of a second slope that is formed more continuously and has a slope toward an inward direction of the width;
A lens barrel device comprising: a second frame member having a cam follower having a maximum diameter located in the cam groove, engaging with the first slope, and slidingly contacting the cam follower.

7. The lens barrel device according to claim 5, wherein the first frame member is provided with a cam groove on an outer peripheral surface.

7. The lens barrel device according to claim 5, wherein the first frame member is provided with a cam groove on an inner peripheral surface.

A pair of first slopes, each having a bottom having a predetermined width, facing each other and extending from the bottom toward the peripheral surface, and having a slope so as to increase the width, and one of the pair of first slopes A lens barrel device comprising a frame member formed continuously from the surface and provided with a cam groove formed by the first slope and a second slope having a different slope.

10. The lens barrel device according to claim 9, wherein the slope of the second slope has an angle smaller than an angle formed by a perpendicular to the bottom and the first slope.