JP7155198B2

JP7155198B2 - torque limiter

Info

Publication number: JP7155198B2
Application number: JP2020105548A
Authority: JP
Inventors: 洋裕小林
Original assignee: Origin Co Ltd
Current assignee: Origin Co Ltd
Priority date: 2020-06-18
Filing date: 2020-06-18
Publication date: 2022-10-18
Anticipated expiration: 2040-06-18
Also published as: JP2021196046A

Description

本発明は、相対的に回転可能な外輪部材及び内輪部材と、両者の間に装着されるばね部材とを備え、外輪部材と内輪部材とを相対的に回転させる回転トルクが所定値より大きいと、ばね部材による摩擦力に打ち勝って外輪部材と内輪部材とが相対的に回転するトルクリミッタに関するものである。 The present invention comprises an outer ring member and an inner ring member that are relatively rotatable, and a spring member mounted therebetween, and when the rotational torque for relatively rotating the outer ring member and the inner ring member is greater than a predetermined value. and a torque limiter in which an outer ring member and an inner ring member rotate relative to each other overcoming the frictional force of a spring member.

下記特許文献１には、断面円形の内周面を備えた外輪部材と、外輪部材の内周面に接触して装着されるばね部材と、内輪部材とを具備したトルクリミッタが開示されている。外輪部材と内輪部材とは共通の中心軸を有している。ばね部材は、その全体が円弧状であって自由状態における外径は外輪部材の内周面の径よりも大きい。内輪部材は、ばね部材の内側に配設される内輪と、内輪の径方向外側において軸方向に延出する係合片とを備えている。そして、外輪部材と内輪部材とを相対的に回転させる共通の中心軸周りの回転トルクが付加されると、上記回転トルクが所定値より大きい場合には、ばね部材の外周面と外輪部材の上記内周面との間の摩擦力に打ち勝って外輪部材と内輪部材とが相対的に回転する。 Patent Literature 1 below discloses a torque limiter including an outer ring member having an inner peripheral surface with a circular cross section, a spring member mounted in contact with the inner peripheral surface of the outer ring member, and an inner ring member. . The outer ring member and the inner ring member have a common central axis. The spring member has an arcuate shape as a whole and has an outer diameter larger than the diameter of the inner peripheral surface of the outer ring member in a free state. The inner ring member includes an inner ring arranged inside the spring member and an engaging piece extending axially outside the inner ring in the radial direction. Then, when a rotational torque around the common central axis for relatively rotating the outer ring member and the inner ring member is applied, if the rotational torque is greater than a predetermined value, the outer peripheral surface of the spring member and the outer ring member are rotated. The outer ring member and the inner ring member rotate relative to each other overcoming the frictional force between them.

特開２００４－１９０７３１号公報Japanese Patent Application Laid-Open No. 2004-190731

特許文献１に開示されているトルクリミッタにあっては、外輪部材と内輪部材とを相対的に回転させる共通の中心軸周りの回転トルクが付加されたときに、係合片はばね部材を構成する線材の周方向端面と当接してこれを周方向に押すことから、ばね部材の外周面は外輪部材の内周面と強固に密接した状態のまま摺動することとなり、ばね部材の外周面及び外輪の内周面は著しく摩耗し、トルクリミッタの使用寿命が短くなる。 In the torque limiter disclosed in Patent Document 1, the engagement piece constitutes a spring member when rotational torque about a common central axis that relatively rotates the outer ring member and the inner ring member is applied. Since the outer peripheral surface of the spring member contacts with the circumferential end surface of the wire rod and pushes it in the circumferential direction, the outer peripheral surface of the spring member slides while firmly in close contact with the inner peripheral surface of the outer ring member. In addition, the inner peripheral surface of the outer ring is significantly worn, shortening the service life of the torque limiter.

本発明は上記事実に鑑みてなされたものであり、その主たる技術的課題は、外輪部材と内輪部材とが相対回転することで生じる、ばね部材の外周面及び外輪部材の内周面の摩耗を軽減させて、使用寿命の長い新規且つ改良されたトルクリミッタを提供することである。 The present invention has been made in view of the above facts, and its main technical problem is to prevent the wear of the outer peripheral surface of the spring member and the inner peripheral surface of the outer ring member caused by the relative rotation of the outer ring member and the inner ring member. To provide a new and improved torque limiter which reduces torque and has a long service life.

本発明者は、鋭意検討の結果、ばね部材の作用部の周方向両端に内輪部材の係合片と当接可能なフック部を接続し、係合片がフック部と当接してこれを周方向に押すことで、係合片によって押されたフック部の基端が径方向内側に変位せしめられるようにすることで、上記主たる技術的課題が解決されることを見出した。 As a result of intensive studies, the present inventors have discovered that hook portions that can abut against the engaging pieces of the inner ring member are connected to both circumferential ends of the action portion of the spring member, and the engaging pieces come into contact with the hook portions and rotate around the hook portions. It has been found that the above main technical problem can be solved by displacing the proximal end of the hook portion pushed by the engaging piece radially inward by pushing in the direction.

即ち、本発明によれば、上記主たる技術的課題を解決するトルクリミッタとして、断面円形の内周面を備えた外輪部材、前記外輪部材の前記内周面に接触して装着されるばね部材、及び前記外輪部材と共通の中心軸を有する内輪部材を具備し、
前記ばね部材は円弧状の作用部を備え、自由状態における前記作用部の外径は前記外輪部材の前記内周面の径よりも大きく、
前記内輪部材は、前記ばね部材の内側に配設される内輪と、前記内輪の径方向外側において軸方向に延出する係合片とを備え、
前記外輪部材と前記内輪部材とを相対的に回転させる前記共通の中心軸周りの回転トルクが付加されると前記係合片が前記ばね部材に作用し、前記回転トルクが所定値より大きい場合には、前記ばね部材の外周面と前記外輪部材の前記内周面との間の摩擦力に打ち勝って前記外輪部材と前記内輪部材とが相対的に回転するトルクリミッタにおいて、
前記ばね部材の前記作用部の周方向両端には夫々径方向内側に湾曲して延びるフック部が接続されており、前記回転トルクが付加されると、前記フック部が前記係合片によって周方向に押されて前記フック部の基端は径方向内側に変位する、ことを特徴とするトルクリミッタが提供される。 That is, according to the present invention, as a torque limiter for solving the above main technical problems, there is provided an outer ring member having an inner peripheral surface with a circular cross section, and a spring portion mounted in contact with the inner peripheral surface of the outer ring member. and an inner ring member having a common central axis with the outer ring member ,
The spring member has an arc-shaped working portion, and the outer diameter of the working portion in a free state is larger than the diameter of the inner peripheral surface of the outer ring member,
The inner ring member includes an inner ring arranged inside the spring member and an engaging piece extending axially outside the inner ring in a radial direction,
When rotational torque around the common central axis for relatively rotating the outer ring member and the inner ring member is applied, the engaging piece acts on the spring member, and when the rotational torque is greater than a predetermined value, the engagement piece acts on the spring member . is a torque limiter in which the outer ring member and the inner ring member rotate relative to each other by overcoming the frictional force between the outer peripheral surface of the spring member and the inner peripheral surface of the outer ring member,
Hook portions extending inwardly in the radial direction are connected to both ends of the acting portion of the spring member in the circumferential direction. The torque limiter is characterized in that the proximal end of the hook portion is displaced radially inwardly by being pushed by the force.

好ましくは、前記フック部は、前記基端を一端として径方向内側に向かって湾曲して延出する遷移領域と、前記遷移領域の他端に接続される主要領域とを有している。この場合には、前記主要領域の少なくとも基端部分は、前記基端における前記作用部の接線方向に対し、前記作用部の内周面に接近する方向に見て０乃至９０度の角度で傾斜しているのがよい。前記内輪部材は、前記内輪が形成された内側体と、前記係合片が形成された外側体とを相対回転不能な状態で組み合わせて構成されるのが好適である。前記内輪は転がり軸受であるのがよい。 Preferably, the hook portion has a transition region curved radially inwardly extending from the proximal end, and a main region connected to the other end of the transition region. In this case, at least the base end portion of the main region is inclined at an angle of 0 to 90 degrees with respect to the tangential direction of the action portion at the base end when viewed in a direction approaching the inner peripheral surface of the action portion. It is good to have The inner ring member is preferably configured by combining an inner body having the inner ring and an outer body having the engaging pieces in a non-rotatable manner. The inner ring is preferably a rolling bearing.

本発明のトルクリミッタにあっては、係合片がフック部と当接してこれを周方向に押すと、係合片によって押されたフック部の基端が径方向内側に変位せしめられる。これにより、かかる基端に接続されたばね部材の作用部の周方向端部は外輪部材の内周面から離隔し、ばね部材の外周面と外輪部材の内周面との間の摩擦力は緩和される。それ故に、外輪部材と内輪部材とが相対的に回転する際には、ばね部材の外周面及び外輪部材の内周面の摩耗が軽減され、トルクリミッタの使用寿命が長くなる。 In the torque limiter of the present invention, when the engaging piece contacts the hook portion and pushes it in the circumferential direction, the proximal end of the hook portion pushed by the engaging piece is displaced radially inward. As a result, the circumferential end of the acting portion of the spring member connected to the proximal end is separated from the inner peripheral surface of the outer ring member, and the frictional force between the outer peripheral surface of the spring member and the inner peripheral surface of the outer ring member is reduced. be done. Therefore, when the outer ring member and the inner ring member rotate relative to each other, wear of the outer peripheral surface of the spring member and the inner peripheral surface of the outer ring member is reduced, and the service life of the torque limiter is extended.

本発明に従って構成されたトルクリミッタの好適実施形態の全体構成を示す図。1 is a diagram showing the overall configuration of a preferred embodiment of a torque limiter constructed according to the present invention; FIG. 図１に示すトルクリミッタのＢ－Ｂ断面図。BB sectional view of the torque limiter shown in FIG. 図１に示すトルクリミッタの外輪部材を単体で示す図。FIG. 2 is a view showing an outer ring member alone of the torque limiter shown in FIG. 1; 図１に示すトルクリミッタのばね部材を単体で示す図。FIG. 2 is a view showing a single spring member of the torque limiter shown in FIG. 1; 図１に示すトルクリミッタの内輪部材の内側体を単体で示す図。FIG. 2 is a view showing alone an inner body of an inner ring member of the torque limiter shown in FIG. 1; 図１に示すトルクリミッタの内輪部材の外側体を単体で示す図。FIG. 2 is a view showing alone an outer body of an inner ring member of the torque limiter shown in FIG. 1; 図１に示すトルクリミッタのシールド板を単体で示す図。FIG. 2 is a view showing a single shield plate of the torque limiter shown in FIG. 1; 図１に示すトルクリミッタにおいて、外輪部材と内輪部材とが相対回転しているときのＢ－Ｂ断面図。FIG. 2 is a cross-sectional view along line BB of the torque limiter shown in FIG. 1 when the outer ring member and the inner ring member are relatively rotating; 図４に示すばね部材の変形例を単体で示す図。The figure which shows the modification of the spring member shown in FIG. 4 alone.

以下、添付図面を参照して、本発明に従って構成されるトルクリミッタの好適実施形態について、更に詳述する。 Preferred embodiments of the torque limiter constructed according to the present invention will now be described in further detail with reference to the accompanying drawings.

図１及び図２を参照して説明すると、全体が番号２で示される本発明に従って構成されたトルクリミッタは、外輪部材４と、ばね部材６と、内輪部材８とを備えており、外輪部材４と内輪部材８とは共通の中心軸ｏを有している。 1 and 2, a torque limiter constructed in accordance with the present invention, indicated generally by the numeral 2, comprises an outer ring member 4, a spring member 6, an inner ring member 8, and an outer ring member 4 and the inner ring member 8 have a common central axis o.

図１及び図２と共に図３を参照して説明すると、外輪部材４は金属製であって、円筒形状の支持壁１０を備えており、支持壁１０には断面円形の内周面１２が規定されている。支持壁１０の軸方向片端部（図１及び図３のＡ－Ａ断面において右側端部）には、径方向外側に延出した円環形状の接続壁１４が形成されており、支持壁１０は接続壁１４を介して筒状の外輪外歯歯車１６の内周面に接続されている。外輪外歯歯車１６は、図示しない駆動部材及び従動部材のいずれか一方に接続される。外輪部材４は、内周面１２の径よりも大きな径を有し且つ中心軸が上記共通の中心軸ｏと共通である断面円形の空間部１８を備えている。空間部１８は外輪外歯歯車１６の内側に規定されており、内周面１２と軸方向に隣接して配置されている。空間部１８には後述するシールド板が配置される。 3 together with FIGS. 1 and 2, the outer ring member 4 is made of metal and has a cylindrical support wall 10. The support wall 10 defines an inner peripheral surface 12 having a circular cross section. It is An annular connection wall 14 extending radially outward is formed at one end in the axial direction of the support wall 10 (the right end in the AA section of FIGS. 1 and 3). is connected to the inner peripheral surface of the cylindrical outer ring external tooth gear 16 via the connection wall 14 . The outer ring external gear 16 is connected to either a driving member or a driven member (not shown). The outer ring member 4 has a space portion 18 having a circular cross-section having a diameter larger than that of the inner peripheral surface 12 and having a central axis common to the common central axis o. The space 18 is defined inside the outer ring externally toothed gear 16 and arranged adjacent to the inner peripheral surface 12 in the axial direction. A shield plate, which will be described later, is arranged in the space portion 18 .

図２を参照して説明すると、ばね部材６は外輪部材４の内周面１２に接触して装着されている。図４も参照して説明すると、ばね部材６は断面が略正方形である金属製の線材を塑性変形させることで形成され、円弧状の作用部２０を備えている。自由状態における作用部２０の外径は外輪部材４の内周面１２の径よりも大きい。このことから、ばね部材６は、作用部２０が縮径せしめられた状態でその外周面が外輪部材４の内周面１２と対向するようにして外輪部材４の内側に配置され、その後に上記縮径を解除することで外輪部材４の内周面１２に接触して装着される。これにより、ばね部材６が外輪部材４の内周面１２に装着された状態にあっては、ばね部材６の作用部２０の外周面は外輪部材４の内周面１２に密接する。ばね部材６の少なくとも作用部２０にはグリスの如き潤滑剤が塗布されているのが好ましい。ばね部材６の作用部２０の周方向両端には、後述する係合片と当接可能なフック部２２が接続されている。フック部２２は、その基端２４を一端として径方向内側に向かって湾曲して延出する遷移領域２２ａと、遷移領域２２ａの他端に接続される主要領域２２ｂとを有している。そして、主要領域２２ｂの少なくとも基端部分は、基端２４における作用部２０の接線Ｌに対し、作用部２０の内周面に接近する方向に見て０乃至９０度の角度θで傾斜している。図示の実施形態においては、主要領域２２ｂはその全体が実質上直線であり、上記角度θは４０度である。 Referring to FIG. 2, the spring member 6 is mounted in contact with the inner peripheral surface 12 of the outer ring member 4 . Referring also to FIG. 4 , the spring member 6 is formed by plastically deforming a metal wire having a substantially square cross section, and has an arc-shaped working portion 20 . The outer diameter of the acting portion 20 in the free state is larger than the diameter of the inner peripheral surface 12 of the outer ring member 4 . For this reason, the spring member 6 is arranged inside the outer ring member 4 so that the outer peripheral surface of the spring member 6 faces the inner peripheral surface 12 of the outer ring member 4 in a state where the action portion 20 is reduced in diameter. By canceling the diameter reduction, it is mounted in contact with the inner peripheral surface 12 of the outer ring member 4 . Accordingly, when the spring member 6 is attached to the inner peripheral surface 12 of the outer ring member 4 , the outer peripheral surface of the acting portion 20 of the spring member 6 is in close contact with the inner peripheral surface 12 of the outer ring member 4 . Preferably, at least the acting portion 20 of the spring member 6 is coated with a lubricant such as grease. Hook portions 22 are connected to both ends of the action portion 20 of the spring member 6 in the circumferential direction so as to be capable of coming into contact with engagement pieces described later. The hook portion 22 has a transition region 22a curved radially inwardly extending from its base end 24, and a main region 22b connected to the other end of the transition region 22a. At least the base end portion of the main region 22b is inclined at an angle θ of 0 to 90 degrees with respect to the tangential line L of the action portion 20 at the base end 24 when viewed in a direction approaching the inner peripheral surface of the action portion 20. there is In the illustrated embodiment, the major region 22b is substantially straight throughout and the angle θ is 40 degrees.

図１及び図２を参照して説明すると、内輪部材８は、ばね部材６の内側に配設される内輪２６と、内輪２６の径方向外側において軸方向に延出する係合片２８とを備えている。図示の実施形態においては、内輪部材８は、内輪２６が形成された金属製の内側体３０と、係合片２８が形成された金属製の外側体３２とを相対回転不能な状態で組み合わせて構成されている。所望ならば、内側体３０と外側体３２とを一体で形成してもよいが、別体で形成して相互に組み合わせた方が動作時の異音や振動を軽減させることができ好ましい。 1 and 2, the inner ring member 8 includes an inner ring 26 disposed inside the spring member 6 and an engaging piece 28 extending axially outside the inner ring 26 in the radial direction. I have. In the illustrated embodiment, the inner ring member 8 is formed by combining a metal inner body 30 formed with an inner ring 26 and a metal outer body 32 formed with engaging pieces 28 in a non-rotatable state. It is configured. If desired, the inner body 30 and the outer body 32 may be integrally formed, but it is preferable to form them separately and combine them with each other because noise and vibration during operation can be reduced.

内側体３０について図５も参照して説明すると、図示の実施形態においては、内輪２６は転がり軸受であり、二重の円筒壁３４と、かかる二重の円筒壁３４の内部に配設された複数個のコロ３６とを備えている。かような転がり軸受の構造は周知であるため、その詳細な説明については省略する。二重の円筒壁３４の内側には図１のＡ－Ａ断面において二点鎖線で示されるシャフトが挿通され、かかるシャフトによってトルクリミッタ２全体が支持される。二重の円筒壁３４の軸方向他端部（図１及び図５のＡ－Ａ断面において左側端部）の外周面には径方向外側に向かって延出する略円環状のフランジ３８が形成されている。フランジ３８には直径方向に対向して一対の切欠き４０が形成されている。 Referring also to FIG. 5 for the inner body 30, in the illustrated embodiment the inner ring 26 is a rolling bearing and has a double cylindrical wall 34 and a A plurality of rollers 36 are provided. Since the structure of such a rolling bearing is well known, a detailed description thereof will be omitted. A shaft indicated by a chain double-dashed line in the AA cross section of FIG. 1 is inserted through the inside of the double cylindrical wall 34, and the torque limiter 2 as a whole is supported by this shaft. A substantially annular flange 38 extending radially outward is formed on the outer peripheral surface of the other axial end of the double cylindrical wall 34 (the left end in the AA section of FIGS. 1 and 5). It is A pair of notches 40 are formed in the flange 38 diametrically opposed to each other.

続いて、外側体３２について図６も参照して説明すると、外側体３２は、中央に円形の開口４２が形成された円板形状の基壁４４を備えている。基壁４４の軸方向片側面（図１及び図６のＡ－Ａ断面において右側側面）の中央には、開口４２の外周縁を囲繞して肉厚が局部的に低減せしめられた略円形の凹部４６が形成されている。凹部４６は内側体３０のフランジ３８と対応する形状であって、直径方向において平行であって共に直線状である一対の拡張部４８を有している。そして、凹部４６にフランジ３８が嵌り込むことで、内側体３０と外側体３２とは回転不能な状態で組み合わされる。上記係合片２８は、凹部４６の径方向外側において基壁４４から軸方向片側に延出している。係合片２８は基壁４４に対し垂直な矩形形状であって、その径方向内側面は、図６の右図において一対の拡張部４８の一方の外側縁と整合している。凹部４６の径方向外側には軸方向片側に延出した係止片５０も形成されている。係止片５０は係合片２８と同一の形状であって、その径方向内側面は図６の右図において一対の拡張部４８の他方の外側縁と整合している。このことから、係合片２８及び係止片５０の径方向内側面は直径方向に対向して相互に並行である。そして、係合片２８及び係止片５０の径方向外側面には夫々、径方向外側に突出する係止部５２が形成されている。係合片２８及び係止片５０の径方向外側には長円形の貫通穴５４が夫々形成されている。貫通穴５４は成形上の理由により設けられるものであり軸方向に貫通している。基壁４４の外周縁は筒状の内輪外歯歯車５６の内周面に接続されており、内輪外歯歯車５６は、図示しない駆動部材及び従動部材のいずれか他方に接続される。 Next, the outer body 32 will also be described with reference to FIG. 6. The outer body 32 has a disk-shaped base wall 44 with a circular opening 42 formed in the center. At the center of one axial side surface of the base wall 44 (the right side surface in the AA cross section of FIGS. 1 and 6), there is a substantially circular shape which surrounds the outer peripheral edge of the opening 42 and whose thickness is locally reduced. A recess 46 is formed. The recess 46 is shaped correspondingly to the flange 38 of the inner body 30 and has a pair of diametrically parallel extensions 48 that are both straight. By fitting the flange 38 into the recess 46, the inner body 30 and the outer body 32 are combined in a non-rotatable state. The engaging piece 28 extends to one side in the axial direction from the base wall 44 on the radially outer side of the recess 46 . The engaging piece 28 has a rectangular shape perpendicular to the base wall 44, and its radial inner surface is aligned with one outer edge of the pair of extended portions 48 in the right view of FIG. A locking piece 50 extending to one side in the axial direction is also formed on the radially outer side of the recess 46 . The locking piece 50 has the same shape as the engaging piece 28, and its radial inner surface is aligned with the other outer edge of the pair of extended portions 48 in the right view of FIG. Therefore, the radial inner surfaces of the engaging piece 28 and the locking piece 50 are diametrically opposed and parallel to each other. A locking portion 52 projecting radially outward is formed on each of the radially outer side surfaces of the engaging piece 28 and the locking piece 50 . Oval through holes 54 are formed on the radially outer sides of the engaging piece 28 and the locking piece 50, respectively. The through hole 54 is provided for molding reasons and penetrates in the axial direction. The outer peripheral edge of the base wall 44 is connected to the inner peripheral surface of a cylindrical inner ring external tooth gear 56, and the inner ring external tooth gear 56 is connected to either one of a driving member and a driven member (not shown).

図１を参照して説明すると、図示の実施形態にあっては、外輪部材４に設けられた空間部１８には番号５８で示されるシールド板が配置されている。図７も参照して説明すると、シールド板５８は金属製の薄板円形形状であり、中央領域には開口６０が形成されている。開口６０は円形の中央部６２と、中央部６２の外周縁が比較的大きく径方向外側に偏倚せしめられた大偏倚部６４と、中央部６２の外周縁が比較的小さく径方向外側に偏倚せしめられた小偏倚部６６とを備えている。大偏倚部６４及び小偏倚部６６は夫々直径方向に対向して２つずつ設けられており、大偏倚部６４と小偏倚部６６とは周方向に９０度の角度間隔を有して配置されている。２つの大偏倚部６４には夫々、シールド板５８の内周縁から径方向内側に向かって幾分延出した後に軸方向他側（図１及び図６のＡ－Ａ断面において左側）に起立するＬ字形状の被係止片６８が形成されている。２つの被係止片６８の径方向内側面は直径方向に対向し相互に並行である。図７のＡ－Ａ断面及びＣ－Ｃ断面を参照することによって理解されるとおり、被係止片６８には径方向及び軸方向に貫通するＬ字形状の貫通穴７０が形成されている。一方、２つの小偏倚部６６には夫々、シールド板５８の内周縁から径方向内側に延出した直後に軸方向他側に起立する延出片７２が形成されている。２つの延出片７２の径方向内側面は直径方向に対向し相互に並行である。 Referring to FIG. 1, in the illustrated embodiment, a shield plate indicated by numeral 58 is arranged in the space 18 provided in the outer ring member 4. As shown in FIG. Referring also to FIG. 7, the shield plate 58 is made of metal and has a circular shape, and an opening 60 is formed in the central region. The opening 60 has a circular center portion 62, a large deviation portion 64 where the outer periphery of the center portion 62 is biased radially outward to a relatively large extent, and an outer periphery of the center portion 62 which is biased radially outward relatively small. and a small deflection portion 66 which is aligned. Two large-biased portions 64 and two small-biased portions 66 are provided diametrically opposed to each other, and the large-biased portions 64 and small-biased portions 66 are arranged with an angular interval of 90 degrees in the circumferential direction. ing. Each of the two large biased portions 64 extends radially inward from the inner peripheral edge of the shield plate 58 to some extent, and then stands on the other side in the axial direction (the left side in the AA section of FIGS. 1 and 6). An L-shaped locked piece 68 is formed. The radially inner side surfaces of the two locked pieces 68 are diametrically opposed and parallel to each other. As can be understood by referring to the AA section and the CC section of FIG. 7, an L-shaped through hole 70 penetrating in the radial direction and the axial direction is formed in the locked piece 68 . On the other hand, each of the two small biased portions 66 is formed with an extending piece 72 that extends radially inward from the inner peripheral edge of the shield plate 58 and stands up on the other side in the axial direction. The radial inner surfaces of the two extension pieces 72 are diametrically opposed and parallel to each other.

上述したシールド板５８は、被係止片６８の軸方向先端が内輪部材８の外側体３２に形成された係止部５２と当接するようにして内輪部材８（及び外輪部材４）に対し整合された後に、内輪部材８に対して軸方向に強制せしめられることで外輪部材４の空間部１８に位置することとなる（図１のＡ－Ａ断面図を参照されたい）。シールド板５８が内輪部材８に対して軸方向に強制せしめられると、被係止片６８の軸方向先端が上記係止部５２を弾性的に乗り越え、被係止片６８に形成された貫通穴７０が係止部５２に係止される。つまり、貫通穴７０は係合片２８及び係止片５０の夫々に形成された係止部５２と協働する被係止部であって、係止部５２と被係止部（貫通穴７０）とが係止手段を構成する。かような係止手段の存在により、シールド板５８は内輪部材８と一体となって回転可能となると共に内輪部材８からの脱落が防止される。シールド板５８が外輪部材４の空間部１８に配置された状態にあっては、図２に示すとおり、シールド板５８に形成された延出片７２の径方向内側面が内輪２６の外周面と対向する。これにより、シールド板５８が内輪部材８と一体となって回転する際に、内輪部材８に対するシールド板５８の芯ぶれが防止される。 The shield plate 58 described above is aligned with the inner ring member 8 (and the outer ring member 4) so that the axial tip of the locked piece 68 abuts on the locking portion 52 formed on the outer body 32 of the inner ring member 8. After that, it is positioned in the space 18 of the outer ring member 4 by being axially forced against the inner ring member 8 (see the AA sectional view of FIG. 1). When the shield plate 58 is axially forced against the inner ring member 8 , the axial tip of the locked piece 68 elastically climbs over the locking portion 52 , and the through hole formed in the locked piece 68 is closed. 70 is locked to the locking portion 52 . In other words, the through hole 70 is a locked portion that cooperates with the locking portion 52 formed in each of the engaging piece 28 and the locking piece 50. The locking portion 52 and the locked portion (the through hole 70 ) constitute the locking means. Due to the presence of such locking means, the shield plate 58 can rotate integrally with the inner ring member 8 and is prevented from coming off the inner ring member 8 . When the shield plate 58 is arranged in the space 18 of the outer ring member 4, the radially inner surface of the extending piece 72 formed on the shield plate 58 is aligned with the outer peripheral surface of the inner ring 26, as shown in FIG. opposite. As a result, when the shield plate 58 rotates integrally with the inner ring member 8 , the shield plate 58 is prevented from wobbling with respect to the inner ring member 8 .

続いて、図２と共に図８を参照してトルクリミッタ２の作動について説明する。図２に示す状態から、内輪部材８が外輪部材４に対して反時計方向に回転すると、図８に示すとおり、内輪部材８の外側体３２に形成された係合片２８も反時計方向に回転し、係合片２８はばね部材６のフック部２２と当接してこれを反時計方向に押す。そして、外輪部材４と内輪部材８との間に所定値より大きい回転トルクが付加されると、ばね部材６の作用部２０の外周面が外輪部材４の内周面１２に対して滑りを生じ、ばね部材６は内輪部材８（及びシールド板５８）と一体となって外輪部材４に対して回転する。このとき、本発明のトルクリミッタ２にあっては、係合片２８がフック部２２と当接してこれを周方向に押すと、係合片２８によって押されたフック部２２の基端２４が径方向内側に変位せしめられる（図２と図８とを比較参照されたい）。これにより、かかる基端２４に接続されたばね部材６の作用部２０の周方向端部は外輪部材４の内周面１２から離隔し、ばね部材６の外周面と外輪部材４の内周面１２との間の摩擦力は緩和される。それ故に、外輪部材４と内輪部材８とが相対的に回転する際には、ばね部材６の外周面及び外輪部材４の内周面１２の摩耗が軽減され、トルクリミッタの使用寿命が長くなる。上記回転トルクが所定位置以下の場合には、外輪部材４及びばね部材６並びに内輪部材８は一体となって回転する。内輪部材８が外輪部材４に対して時計方向に回転した場合も同様である。 Next, the operation of the torque limiter 2 will be described with reference to FIG. 8 together with FIG. When the inner ring member 8 rotates counterclockwise relative to the outer ring member 4 from the state shown in FIG. 2, the engaging piece 28 formed on the outer body 32 of the inner ring member 8 also rotates counterclockwise as shown in FIG. As it rotates, the engaging piece 28 comes into contact with the hook portion 22 of the spring member 6 and pushes it counterclockwise. When a rotational torque greater than a predetermined value is applied between the outer ring member 4 and the inner ring member 8, the outer peripheral surface of the acting portion 20 of the spring member 6 slides on the inner peripheral surface 12 of the outer ring member 4. , the spring member 6 rotates with respect to the outer ring member 4 integrally with the inner ring member 8 (and the shield plate 58). At this time, in the torque limiter 2 of the present invention, when the engaging piece 28 contacts the hook portion 22 and pushes it in the circumferential direction, the base end 24 of the hook portion 22 pushed by the engaging piece 28 It is displaced radially inward (compare FIGS. 2 and 8). As a result, the circumferential end portion of the acting portion 20 of the spring member 6 connected to the base end 24 is separated from the inner peripheral surface 12 of the outer ring member 4 so that the outer peripheral surface of the spring member 6 and the inner peripheral surface 12 of the outer ring member 4 are separated from each other. The frictional force between Therefore, when the outer ring member 4 and the inner ring member 8 rotate relative to each other, wear of the outer peripheral surface of the spring member 6 and the inner peripheral surface 12 of the outer ring member 4 is reduced, and the service life of the torque limiter is extended. . When the rotational torque is equal to or lower than the predetermined position, the outer ring member 4, the spring member 6 and the inner ring member 8 rotate together. The same applies when the inner ring member 8 rotates clockwise with respect to the outer ring member 4 .

以上、添付した図面を参照して本発明のトルクリミッタについて詳述したが、本発明は上述した実施形態に限定されるものではなく、本発明の範囲から逸脱しない範囲内において種々の変形が可能である。例えば、ばね部材は図４に示す形態に替えて、図９に示すような形態であってもよい。図９に示すばね部材６´にあっては、主要領域２２ｂ´の全体がＵ字形状である。主要領域２２ｂ´の基端部分は、基端２４´における作用部２０´の接線Ｌ´と略平行であり、上記角度θは略０度である。かようなばね部材６´にあっては、内輪部材が外輪部材に対して回転した際に、係合片が主要領域２２ｂ´の内側に規定される凹所２２ｃ´に進入して主要領域２２ｂ´を周方向に押すことで、所謂てこの原理を利用して効果的にフック部２２´の基端２４´を径方向内側に変位させることができる。 Although the torque limiter of the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the scope of the present invention. is. For example, the spring member may have a form as shown in FIG. 9 instead of the form shown in FIG. In the spring member 6' shown in FIG. 9, the entire main region 22b' is U-shaped. The base end portion of the main region 22b' is substantially parallel to the tangential line L' of the action portion 20' at the base end 24', and the angle θ is substantially 0 degree. In such a spring member 6', when the inner ring member rotates with respect to the outer ring member, the engaging piece enters the recess 22c' defined inside the main region 22b' and moves toward the main region 22b'. ' can be effectively displaced inward in the radial direction using the so-called principle of leverage.

２：トルクリミッタ
４：外輪部材
６：ばね部材
８：内輪部材
１２：内周面
２０：作用部
２２：フック部
２４：（フック部の）基端
２６：内輪
２８：係合片 2: Torque limiter 4: Outer ring member 6: Spring member 8: Inner ring member 12: Inner peripheral surface 20: Acting portion 22: Hook portion 24: Base end (of hook portion) 26: Inner ring 28: Engaging piece

Claims

断面円形の内周面を備えた外輪部材、前記外輪部材の前記内周面に接触して装着されるばね部材、及び前記外輪部材と共通の中心軸を有する内輪部材を具備し、
前記ばね部材は円弧状の作用部を備え、自由状態における前記作用部の外径は前記外輪部材の前記内周面の径よりも大きく、
前記内輪部材は、前記ばね部材の内側に配設される内輪と、前記内輪の径方向外側において軸方向に延出する係合片とを備え、
前記外輪部材と前記内輪部材とを相対的に回転させる前記共通の中心軸周りの回転トルクが付加されると前記係合片が前記ばね部材に作用し、前記回転トルクが所定値より大きい場合には、前記ばね部材の外周面と前記外輪部材の前記内周面との間の摩擦力に打ち勝って前記外輪部材と前記内輪部材とが相対的に回転するトルクリミッタにおいて、
前記ばね部材の前記作用部の周方向両端には夫々径方向内側に湾曲して延びるフック部が接続されており、前記回転トルクが付加されると、前記フック部が前記係合片によって周方向に押されて前記フック部の基端は径方向内側に変位する、ことを特徴とするトルクリミッタ。 An outer ring member having an inner peripheral surface with a circular cross section, a spring member mounted in contact with the inner peripheral surface of the outer ring member , and an inner ring member having a common central axis with the outer ring member ,
The spring member has an arc-shaped working portion, and the outer diameter of the working portion in a free state is larger than the diameter of the inner peripheral surface of the outer ring member,
The inner ring member includes an inner ring arranged inside the spring member and an engaging piece extending axially outside the inner ring in a radial direction,
When rotational torque around the common central axis for relatively rotating the outer ring member and the inner ring member is applied, the engaging piece acts on the spring member, and when the rotational torque is greater than a predetermined value, the engagement piece acts on the spring member . is a torque limiter in which the outer ring member and the inner ring member rotate relative to each other by overcoming the frictional force between the outer peripheral surface of the spring member and the inner peripheral surface of the outer ring member,
Hook portions extending inwardly in the radial direction are connected to both ends of the acting portion of the spring member in the circumferential direction. A torque limiter characterized in that the base end of the hook portion is displaced radially inwardly by being pushed by the force.

前記フック部は、前記基端を一端として径方向内側に向かって湾曲して延出する遷移領域と、前記遷移領域の他端に接続される主要領域とを有している、請求項１に記載のトルクリミッタ。 2. The hook portion has a transition region curved radially inwardly extending from the base end as one end, and a main region connected to the other end of the transition region. Torque limiter as described.

前記主要領域の少なくとも基端部分は、前記基端における前記作用部の接線方向に対し、前記作用部の内周面に接近する方向に見て０乃至９０度の角度で傾斜している、請求項２に記載のトルクリミッタ。 At least the base end portion of the main region is inclined at an angle of 0 to 90 degrees with respect to the tangential direction of the action portion at the base end, when viewed in a direction approaching the inner peripheral surface of the action portion. 3. A torque limiter according to item 2.

前記内輪部材は、前記内輪が形成された内側体と、前記係合片が形成された外側体とを相対回転不能な状態で組み合わせて構成される、請求項１乃至３のいずれかに記載のトルクリミッタ。 4. The inner ring member according to any one of claims 1 to 3 , wherein the inner ring member is configured by combining an inner body formed with the inner ring and an outer body formed with the engaging piece in a non-rotatable state. torque limiter.

前記内輪は転がり軸受である、請求項１乃至４のいずれかに記載のトルクリミッタ。 5. The torque limiter according to claim 1 , wherein said inner ring is a rolling bearing.