JP5369989B2

JP5369989B2 - Drip-proof bayonet structure of lens barrel

Info

Publication number: JP5369989B2
Application number: JP2009188406A
Authority: JP
Inventors: 悠司小暮
Original assignee: Ricoh Imaging Co Ltd
Current assignee: Ricoh Imaging Co Ltd
Priority date: 2009-08-17
Filing date: 2009-08-17
Publication date: 2013-12-18
Anticipated expiration: 2029-08-17
Also published as: JP2011039384A

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel capable of performing a smooth relative rotation operation, while having a drip-proof structure, in the lens barrel in which a circumferential groove is formed by a pair of groove forming flanges in one of two relatively rotating cylindrical members, a bayonet pawl fitted into the circumferential groove is formed in the other one of the two relatively rotating cylindrical members, and a cutout for guiding the bayonet pawl into the inside of the circumferential groove is formed in a specific rotation angle position in a pair of groove forming flanges and the bayonet pawl. SOLUTION: In the drip-proof bayonet structure of the lens barrel, one of the inner circumferential edge and outer circumferential edge of a seal ring is fixed to the cylindrical member on a side having the circumferential groove and a pair of groove forming flanges, and an elastic annular lip comprising the other one of the inner circumferential edge and outer circumferential edge of the seal ring is brought into elastic contact with the cylindrical member on the side having the bayonet pawl so that the bayonet pawl comes into contact with the groove forming flange not having the cutout of a pair of groove forming flanges. COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、レンズ鏡筒の防滴バヨネット構造に関する。 The present invention relates to a drip-proof bayonet structure for a lens barrel.

レンズ鏡筒には、２つの円筒部材をバヨネット結合させて、特定回転角度だけ相対回転可能とする機構が多く採用されている。具体例を挙げると、２つの円筒部材の一方はカメラボディに固定される固定鏡筒であり、他方は、この固定鏡筒に回転可能に支持されるフォーカスリングやズームリングである。バヨネット構造は、２つの円筒部材の一方には、一対の溝形成フランジによって円周溝を形成するとともに、他方にこの円周溝に嵌まるバヨネット爪を形成し、一対の溝形成フランジとバヨネット爪に、特定の回転角度位置において、バヨネット爪を円周溝内に導く切欠を形成して構成されている。 Many lens barrels employ a mechanism in which two cylindrical members are bayonet-coupled so as to be relatively rotatable by a specific rotation angle. As a specific example, one of the two cylindrical members is a fixed barrel fixed to the camera body, and the other is a focus ring or zoom ring that is rotatably supported by the fixed barrel. In the bayonet structure, a circumferential groove is formed in one of the two cylindrical members by a pair of groove forming flanges, and a bayonet claw that fits in the circumferential groove is formed in the other, and the pair of groove forming flange and the bayonet claw In addition, a notch for guiding the bayonet claw into the circumferential groove is formed at a specific rotational angle position.

特開平１１-１１９０７５号公報Japanese Patent Laid-Open No. 11-119075

このようなバヨネット結合された２つの円筒部材を持つレンズ鏡筒においては、バヨネット爪と溝形成フランジの切欠が相互に干渉して滑らかな回転を阻害することが生じる可能性がある。一方、このようなバヨネット構造を持つレンズ鏡筒において、防滴構造を実現する際、そのシールリング（シール部材）は、バヨネット構造とは無関係に設けられており、両者を構成上関連付けるという着眼は存在しなかった。 In such a lens barrel having two cylindrical members connected with a bayonet, the notches of the bayonet claw and the groove-forming flange may interfere with each other and inhibit smooth rotation. On the other hand, in a lens barrel having such a bayonet structure, when realizing a drip-proof structure, the seal ring (seal member) is provided regardless of the bayonet structure, and the focus is to link the two structurally. Did not exist.

本発明は、防滴のために用いるシールリングを、バヨネット爪と溝形成フランジの切欠の相互干渉を防ぐための付勢部材として同時に用いれば、構成が簡単な防滴バヨネット構造が得られるとの着眼に基づいて完成されたものである。 According to the present invention, a drip-proof bayonet structure with a simple structure can be obtained if a seal ring used for drip-proof is simultaneously used as an urging member for preventing mutual interference between notches of a bayonet claw and a groove forming flange. It was completed based on the eyes.

すなわち、本発明によるレンズ鏡筒の防滴バヨネット構造は、相対回転する第１及び第２の円筒部材を有し、第１の円筒部材に、一対の溝形成フランジによって円周溝を形成するとともに、第２の円筒部材にこの円周溝に嵌まるバヨネット爪を形成し、一対の溝形成フランジのいずれか一方に、特定の回転角度位置において、バヨネット爪を円周溝内に導く切欠を形成したレンズ鏡筒において、上記第１の円筒部材に、シールリングの内周端部と外周端部のいずれか一方を固定し、上記シールリングの内周端部と外周端部の他方からなる弾性環状リップを、上記バヨネット爪が上記一対の溝形成フランジのうち上記切欠を持たない溝形成フランジに当接し、かつ上記切欠を持つ溝形成フランジとバヨネット爪との間にクリアランスが生じるように、上記第２の円筒部材に弾接させたことを特徴としている。 That is, the drip-proof bayonet structure of the lens barrel according to the present invention has first and second cylindrical members that rotate relative to each other, and a circumferential groove is formed in the first cylindrical member by a pair of groove forming flanges. The bayonet claw that fits into the circumferential groove is formed in the second cylindrical member, and a notch that guides the bayonet claw into the circumferential groove is formed in one of the pair of groove forming flanges at a specific rotational angle position. In the above lens barrel, one of the inner peripheral end and the outer peripheral end of the seal ring is fixed to the first cylindrical member, and the elastic formed by the other of the inner peripheral end and the outer peripheral end of the seal ring. the annular lip clearance is formed between the groove forming the flange and the bayonet claws which the bayonet claws come into contact with the groove forming a flange not having the notch of the pair of grooves formed flanges, and with the notch To is characterized in that is elastically contacted to the second cylindrical member.

本発明は、２つの円筒部材の内外関係を問わずに適用することができるが、その一態様では、一対の溝形成フランジと円周溝を有する第１の円筒部材を、バヨネット爪を有する第２の円筒部材の内側に位置させることができる。 The present invention can be applied regardless of the internal / external relationship between the two cylindrical members. In one embodiment, the first cylindrical member having a pair of groove forming flanges and a circumferential groove is used as the first cylindrical member having a bayonet claw. It can be located inside the two cylindrical members.

この内外関係では、第１の円筒部材の外周面に、シールリングの内周端部を固定し、第２の円筒部材の軸線直交端面に、シールリングの弾性環状リップを弾接させることができる。 In this internal / external relationship, the inner peripheral end of the seal ring can be fixed to the outer peripheral surface of the first cylindrical member, and the elastic annular lip of the seal ring can be elastically contacted to the axial orthogonal end surface of the second cylindrical member. .

あるいは、第１の円筒部材の軸線直交面に、シールリングの内周端部を固定し、第２の円筒部材の端面に、シールリングの弾性環状リップを弾接させる構成としてもよい。 Or it is good also as a structure which fixes the inner peripheral end part of a seal ring to the axis orthogonal surface of a 1st cylindrical member, and elastically contacts the elastic annular lip of a seal ring with the end surface of a 2nd cylindrical member.

本発明は、相対回転する２つの円筒部材の一方（第１の円筒部材）に、一対の溝形成フランジによって円周溝を形成するとともに、他方（第２の円筒部材）にこの円周溝に嵌まるバヨネット爪を形成し、一対の溝形成フランジの一方に、特定の回転角度位置において、バヨネット爪を円周溝内に導く切欠を形成したレンズ鏡筒において、円周溝及び一対の溝形成フランジを有する側の円筒部材に、シールリングの内周端部と外周端部のいずれか一方を固定し、シールリングの内周端部と外周端部の他方からなる弾性環状リップを、バヨネット爪が一対の溝形成フランジのうち切欠を持たない溝形成フランジに当接するように、バヨネット爪を有する側の円筒部材に弾接させたものであって、防滴のために用いるシールリングを、バヨネット爪と溝形成フランジの切欠の相互干渉を防ぐための付勢部材として同時に用いたので、構成が簡単な防滴バヨネット構造を得ることができる。 According to the present invention, a circumferential groove is formed in one of the two cylindrical members (first cylindrical member) that rotates relative to each other by a pair of groove forming flanges, and the other (second cylindrical member) is formed in the circumferential groove. In a lens barrel in which a bayonet claw to be fitted is formed and a notch for guiding the bayonet claw into the circumferential groove is formed on one of the pair of groove forming flanges at a specific rotational angle position, the circumferential groove and the pair of grooves are formed. One of the inner peripheral end and the outer peripheral end of the seal ring is fixed to the cylindrical member on the side having the flange, and an elastic annular lip comprising the other of the inner peripheral end and the outer peripheral end of the seal ring is attached to the bayonet claw. Of the pair of groove forming flanges is elastically contacted with the cylindrical member on the side having the bayonet claws so as to contact the groove forming flange having no notch, and a seal ring used for drip-proofing is used as the bayonet. claw Since it used simultaneously as urging member for preventing the mutual interference of the cutout of the groove forming the flange can be configured to obtain a simple drip-proof bayonet structure.

本発明によるレンズ鏡筒の防滴バヨネット構造の一実施形態を示す上半断面図である。It is an upper half sectional view showing one embodiment of a drip-proof bayonet structure of a lens barrel according to the present invention. 図１、図４のII-II線に沿う断面図であって、（Ａ）、（Ｂ）はそれぞれ相対回転する２つの円筒部材の異なる相対回転位置を示している。It is sectional drawing which follows the II-II line | wire of FIG. 1, FIG. 4, (A), (B) has shown the different relative rotational position of the two cylindrical members which each rotate relatively. 部材間隔を誇張して示す図１、図４のIII部拡大断面図である。FIG. 5 is an enlarged sectional view of a portion III in FIGS. 1 and 4 exaggeratingly showing a member interval. 本発明によるレンズ鏡筒の防滴バヨネット構造の別の実施形態を示す上半断面図である。It is an upper half sectional view showing another embodiment of a drip-proof bayonet structure of a lens barrel according to the present invention.

図１ないし図３は、本発明によるレンズ鏡筒の防滴バヨネット構造の一実施形態を示している。本実施形態は、共通の軸線Ｏを持つ第１の円筒部材１０と第２の円筒部材２０とを有するレンズ鏡筒に本発明を適用したものである。以下、内側に位置する第１の円筒部材１０を内側円筒部材、外側に位置する第２の円筒部材２０を外側円筒部材と呼ぶ。内側円筒部材１０は例えばカメラボディに固定される固定鏡筒に一体結合された円筒部材であり、この内側円筒部材１０には、その外周に軸線Ｏと直交する互いに平行な一対の（第１、第２の）溝形成フランジ（外方フランジ）１１と１２、及びこの一対の溝形成フランジ１１と１２の間に位置する円周溝１３が形成されている。図１、図３の右方の溝形成フランジ１２の外径は、溝形成フランジ１１の外径より小さい。また、図１、図３の右方の溝形成フランジ１２の高さは、溝形成フランジ１１の高さより小さくなっているが、両フランジ１１、１２の高さは限定されない。外側円筒部材２０は、内側円筒部材１０に一定角度の相対回転を自在に支持されるもので、例えばフォーカスリングまたはズームリングに一体結合された円筒部材である。この外側円筒部材２０には、その内周に、軸線Ｏと直交するバヨネット爪（内方フランジ）２１が形成されている。バヨネット爪２１の軸方向の幅ｗは、図３に誇張して示すように、円周溝１３の軸方向の幅Ｗ（一対の溝形成フランジ１１と１２の間隔）より若干小さい。内側円筒部材１０は、円周溝を有する筒状部材であり、外側円筒部材２０はバヨネット爪を有する筒状部材である。 1 to 3 show an embodiment of a drip-proof bayonet structure of a lens barrel according to the present invention. In the present embodiment, the present invention is applied to a lens barrel having a first cylindrical member 10 and a second cylindrical member 20 having a common axis O. Hereinafter, the first cylindrical member 10 positioned on the inner side is referred to as an inner cylindrical member, and the second cylindrical member 20 positioned on the outer side is referred to as an outer cylindrical member. The inner cylindrical member 10 is, for example, a cylindrical member integrally coupled to a fixed barrel fixed to the camera body. The inner cylindrical member 10 has a pair of parallel (first, first, Second groove forming flanges (outer flanges) 11 and 12 and a circumferential groove 13 positioned between the pair of groove forming flanges 11 and 12 are formed. The outer diameter of the right groove-forming flange 12 in FIGS. 1 and 3 is smaller than the outer diameter of the groove-forming flange 11. Moreover, although the height of the groove forming flange 12 on the right side in FIGS. 1 and 3 is smaller than the height of the groove forming flange 11, the heights of both flanges 11 and 12 are not limited. The outer cylindrical member 20 is supported by the inner cylindrical member 10 so as to be able to freely rotate at a predetermined angle. For example, the outer cylindrical member 20 is a cylindrical member integrally coupled to a focus ring or a zoom ring. The outer cylindrical member 20 is formed with a bayonet claw (inner flange) 21 orthogonal to the axis O on its inner periphery. The axial width w of the bayonet claw 21 is slightly smaller than the axial width W of the circumferential groove 13 (interval between the pair of groove forming flanges 11 and 12), as exaggerated in FIG. The inner cylindrical member 10 is a cylindrical member having a circumferential groove, and the outer cylindrical member 20 is a cylindrical member having a bayonet claw.

バヨネット爪２１は、図示例では、円周方向に間隔をおいて形成した不等幅の３個のバヨネット爪２１Ａ、２１Ｂ、２１Ｃからなっている。別言すると、このバヨネット爪２１Ａ、２１Ｂ、２１Ｃは、内方フランジ２１に周方向に所定間隔をおいて切欠２２を形成することで形成されている。一方、内側円筒部材１０の一方の溝形成フランジ１２には、バヨネット爪２１Ａ、２１Ｂ、２１Ｃを円周溝１３に嵌めるための円周方向に間隔をおいて形成した、不等幅の切欠１４Ａ、１４Ｂ、１４Ｃが形成されている。溝形成フランジ１１には切欠は形成されておらず、円周溝１３側の軸線直交面は平滑面である。 In the illustrated example, the bayonet claw 21 is composed of three unequal width bayonet claws 21A, 21B, and 21C formed at intervals in the circumferential direction. In other words, the bayonet claws 21 A, 21 B, 21 C are formed by forming notches 22 in the inner flange 21 at predetermined intervals in the circumferential direction. On the other hand, in one groove forming flange 12 of the inner cylindrical member 10, unequal width notches 14 A formed at intervals in the circumferential direction for fitting the bayonet claws 21 A, 21 B, 21 C into the circumferential groove 13. 14B and 14C are formed. The groove forming flange 11 is not formed with a notch, and the axis orthogonal surface on the circumferential groove 13 side is a smooth surface.

バヨネット爪２１Ａ、２１Ｂ、２１Ｃは、内側円筒部材１０と外側円筒部材２０の特定回転位相で切欠１４Ａ、１４Ｂ、１４Ｃに嵌まる。バヨネット爪２１Ａ、２１Ｂ、２１Ｃの位置を切欠１４Ａ、１４Ｂ、１４Ｃの位置に合致させて、円周溝１３に嵌めた後、内側円筒部材１０と外側円筒部材２０を相対回転させると、バヨネット爪２１Ａ、２１Ｂ、２１Ｃと一対の溝形成フランジ１１と１２の軸線方向の係合により、内側円筒部材１０と外側円筒部材２０の軸線方向の相対移動は規制され、回転のみが可能となる。バヨネット爪２１と円周溝１３との嵌合部分には、円滑な相対回動を可能にするためグリースが塗布されている。しかし、この内側円筒部材１０と外側円筒部材２０の相対回転に際し、バヨネット爪２１Ａ、２１Ｂ、２１Ｃ（切欠２２）のエッジが切欠１４Ａ、１４Ｂ、１４Ｃのエッジと干渉して、円滑な回転を妨げるおそれがある。 The bayonet claws 21A, 21B, and 21C are fitted into the notches 14A, 14B, and 14C at a specific rotational phase of the inner cylindrical member 10 and the outer cylindrical member 20. After the bayonet claws 21A, 21B, and 21C are aligned with the positions of the cutouts 14A, 14B, and 14C and fitted into the circumferential groove 13, the inner cylindrical member 10 and the outer cylindrical member 20 are rotated relative to each other, and the bayonet claws 21A , 21B, 21C and the pair of groove-forming flanges 11 and 12 in the axial direction, the relative movement in the axial direction of the inner cylindrical member 10 and the outer cylindrical member 20 is restricted, and only rotation is possible. Grease is applied to the fitting portion between the bayonet claw 21 and the circumferential groove 13 to enable smooth relative rotation. However, when the inner cylindrical member 10 and the outer cylindrical member 20 are relatively rotated, the edges of the bayonet claws 21A, 21B, and 21C (notches 22) may interfere with the edges of the notches 14A, 14B, and 14C, thereby preventing smooth rotation. There is.

本実施形態は、このバヨネット爪２１Ａ、２１Ｂ、２１Ｃ（切欠２２）のエッジと切欠１４Ａ、１４Ｂ、１４Ｃのエッジとの干渉現象の防止と、バヨネット爪２１と円周溝１３のバヨネット部分の防滴構造とを単一のシールリング３０で行うものである。ゴム、合成樹脂等の弾性材料からなるシールリング３０は、軸線Ｏを中心とする回転対称形状を有するもので、内側円筒部材１０の外周面に溝形成フランジ１２に隣接させて形成した環状溝１５に嵌まる筒状固定部（内周端部）３１と、この筒状固定部３１から径方向外方に延びて外側円筒部材２０の軸線と直交する端面２３に当接する弾性環状リップ（弾性縁、外周端部）３２を有している。弾性環状リップ３２は、軸線直交端面２３に当接して、外側円筒部材２０を図１の左方、つまりバヨネット爪２１が溝形成フランジ１１に当接する方向に移動付勢する。外側円筒部材２０が左方に押されると、図３に誇張して示すように、内側円筒部材１０の溝形成フランジ１２と、外側円筒部材２０のバヨネット爪２１との間には、クリアランスｃが生じる。このため、内側円筒部材１０と外側円筒部材２０を相対回転させても、外側円筒部材２０のバヨネット爪２１Ａ、２１Ｂ、２１Ｃ（切欠２２）のエッジと内側円筒部材１０の切欠１４Ａ、１４Ｂ、１４Ｃのエッジとの干渉が生じることがない。 In the present embodiment, the interference phenomenon between the edges of the bayonet claws 21A, 21B, 21C (notches 22) and the edges of the notches 14A, 14B, 14C is prevented, and the bayonet portions of the bayonet claws 21 and the circumferential groove 13 are drip-proof. The structure is performed by a single seal ring 30. The seal ring 30 made of an elastic material such as rubber or synthetic resin has a rotationally symmetric shape with the axis O as the center, and the annular groove 15 formed on the outer peripheral surface of the inner cylindrical member 10 adjacent to the groove forming flange 12. A cylindrical fixing portion (inner peripheral end portion) 31 that fits into the cylindrical fixing portion 31, and an elastic annular lip (elastic edge) that extends radially outward from the cylindrical fixing portion 31 and contacts an end surface 23 that is orthogonal to the axis of the outer cylindrical member 20 , Outer peripheral end) 32. The elastic annular lip 32 abuts on the axial orthogonal end surface 23 and urges the outer cylindrical member 20 to move to the left in FIG. 1, that is, in a direction in which the bayonet claw 21 abuts the groove forming flange 11. When the outer cylindrical member 20 is pushed to the left, a clearance c is formed between the groove forming flange 12 of the inner cylindrical member 10 and the bayonet claw 21 of the outer cylindrical member 20, as exaggeratedly shown in FIG. Arise. Therefore, even if the inner cylindrical member 10 and the outer cylindrical member 20 are relatively rotated, the edges of the bayonet claws 21A, 21B, 21C (notches 22) of the outer cylindrical member 20 and the notches 14A, 14B, 14C of the inner cylindrical member 10 There is no interference with the edge.

加えて、本実施形態によると、内側円筒部材１と外側円筒部材２０の間の隙間をシールするシールリング３０によって、バヨネット爪２１と円周溝１３のバヨネット部分に対する防滴構造が実現される。シールリング３０による防滴構造は、図１（図３）の左方から右方への雨水の浸入防止機能を利用する態様と、同右方から左方への雨水の浸入防止機構を利用する態様が可能であり、そのいずれを利用するかは、周辺構造によって定める。また、バヨネット爪２１と円周溝１３との嵌合部分に塗布されたグリースは回転操作性を向上させるだけでなく、防滴効果も高める作用がある。 In addition, according to the present embodiment, a drip-proof structure for the bayonet claw 21 and the bayonet portion of the circumferential groove 13 is realized by the seal ring 30 that seals the gap between the inner cylindrical member 1 and the outer cylindrical member 20. The drip-proof structure by the seal ring 30 is an aspect that uses a rainwater intrusion prevention function from the left to the right in FIG. 1 (FIG. 3) and an aspect that uses a rainwater intrusion prevention mechanism from the right to the left. Which one is to be used is determined by the surrounding structure. Further, the grease applied to the fitting portion between the bayonet claw 21 and the circumferential groove 13 not only improves the rotational operability but also has an effect of improving the drip-proof effect.

図４は、本発明によるレンズ鏡筒の防滴バヨネット構造の別の実施形態を示している。この実施形態は、内側円筒部材１０の軸線直交面に環状溝１６を形成し、シールリング３０の内周端部には、この環状溝１６に嵌まる軸線直交固定リップ３３を形成し、シールリング３０の外周端部には、外側円筒部材２０の軸線直交端面２３に弾接する弾性環状リップ３２を形成した実施形態である。 FIG. 4 shows another embodiment of the drip-proof bayonet structure of the lens barrel according to the present invention. In this embodiment, an annular groove 16 is formed on the axially orthogonal surface of the inner cylindrical member 10, and an axially orthogonal fixing lip 33 that fits into the annular groove 16 is formed on the inner peripheral end of the seal ring 30, and the seal ring In this embodiment, an elastic annular lip 32 that elastically contacts the axially orthogonal end surface 23 of the outer cylindrical member 20 is formed at the outer peripheral end portion of the outer cylindrical member 30.

以上の実施形態では、内側円筒部材１０側に溝形成フランジ（外方フランジ）１１、１２と円周溝１３を形成し、外側円筒部材２０側に内方バヨネット爪（内方フランジ）２１を形成したが、この関係は逆にすることも可能である。すなわち、外側円筒部材２０側に一対の内方溝形成フランジ（内方フランジ）と円周溝を形成し、内側円筒部材１０側に円周溝に嵌まる外方バヨネット爪（外方フランジ）を形成してもよい。また、シールリング３０は、図示例では、内側端部を内側円筒部材１０に固定し、外側端を外側円筒部材２０に弾接させたが、外側端部を外側円筒部材２０に固定し内側端部を内側円筒部材１０の一部に弾接させてもよい。 In the above embodiment, the groove forming flanges (outer flanges) 11 and 12 and the circumferential groove 13 are formed on the inner cylindrical member 10 side, and the inner bayonet claw (inner flange) 21 is formed on the outer cylindrical member 20 side. However, this relationship can be reversed. That is, a pair of inner groove forming flanges (inner flanges) and circumferential grooves are formed on the outer cylindrical member 20 side, and outer bayonet claws (outer flanges) that fit into the circumferential grooves are formed on the inner cylindrical member 10 side. It may be formed. In the illustrated example, the seal ring 30 has an inner end fixed to the inner cylindrical member 10 and an outer end elastically contacted to the outer cylindrical member 20. However, the outer end is fixed to the outer cylindrical member 20 and the inner end is fixed. The portion may be elastically contacted with a part of the inner cylindrical member 10.

Ｏ軸線
１０内側円筒部材
１１１２溝形成フランジ
１３円周溝
１４１４Ａ、１４Ｂ１４Ｃ切欠
２０外側円筒部材
２１２１Ａ２１Ｂ２１Ｃバヨネット爪
２２切欠
２３軸線直交端面
３０シールリング
３１筒状固定部（内周端部）
３２弾性環状リップ（外周端部）
３３軸線直交固定リップ（内周端部） O Axis 10 Inner cylindrical member 11 12 Groove forming flange 13 Circumferential groove 14 14A, 14B 14C Notch 20 Outer cylindrical member 21 21A 21B 21C Bayonet claw 22 Notch 23 Axis orthogonal end face 30 Seal ring 31 Cylindrical fixing part (inner peripheral end) )
32 Elastic annular lip (outer edge)
33 Axis orthogonal fixing lip (inner end)

Claims

A bayonet having first and second cylindrical members that rotate relative to each other, a circumferential groove formed in the first cylindrical member by a pair of groove-forming flanges, and the second cylindrical member fitting into the circumferential groove In a lens barrel in which a claw is formed and a notch that guides a bayonet claw into a circumferential groove is formed in one of a pair of groove forming flanges at a specific rotation angle position.
Either one of the inner peripheral end and the outer peripheral end of the seal ring is fixed to the first cylindrical member;
An elastic annular lip made of other of the inner peripheral end and outer peripheral end of the seal ring, the bayonet claws are abutted on the groove forming flanges without the notch of the pair of grooves formed flange, and the cutout A drip-proof bayonet structure for a lens barrel, wherein the lens barrel is elastically contacted with the second cylindrical member so that a clearance is generated between the groove-forming flange and the bayonet claw .

2. The drip-proof bayonet structure for a lens barrel according to claim 1, wherein the first cylindrical member is a drip-proof bayonet structure for a lens barrel located inside the second cylindrical member.

In the drip-proof bayonet structure of the lens barrel according to claim 2, the inner peripheral end of the seal ring is fixed to the outer peripheral surface of the first cylindrical member, and the axial orthogonal end surface of the second cylindrical member is A drip-proof bayonet structure of the lens barrel in which the elastic annular lip of the seal ring is in elastic contact.

3. The drip-proof bayonet structure of the lens barrel according to claim 2, wherein an inner peripheral end of the seal ring is fixed to an axis orthogonal plane of the first cylindrical member, and the end surface of the second cylindrical member is Drip-proof bayonet structure of lens barrel with elastic ring lip of seal ring elastically contacting.