WO2018168745A1 - Hydraulic auto-tensioner - Google Patents

Hydraulic auto-tensioner Download PDF

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Publication number
WO2018168745A1
WO2018168745A1 PCT/JP2018/009437 JP2018009437W WO2018168745A1 WO 2018168745 A1 WO2018168745 A1 WO 2018168745A1 JP 2018009437 W JP2018009437 W JP 2018009437W WO 2018168745 A1 WO2018168745 A1 WO 2018168745A1
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oil
hydraulic
cylinder
rod
auto tensioner
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PCT/JP2018/009437
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French (fr)
Japanese (ja)
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直人 本多
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Ntn株式会社
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H7/00—Gearings for conveying rotary motion by endless flexible members
    • F16H7/08—Means for varying tension of belts, ropes, or chains
    • F16H7/10—Means for varying tension of belts, ropes, or chains by adjusting the axis of a pulley
    • F16H7/12—Means for varying tension of belts, ropes, or chains by adjusting the axis of a pulley of an idle pulley

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  • This invention relates to a hydraulic auto tensioner that generates a damping force using hydraulic oil.
  • Automobile accessories such as alternators, car air conditioners, and water pumps, are connected to the engine crankshaft by an accessory belt and driven through the accessory belt.
  • a pulley arm provided so as to be swingable about a fulcrum shaft, a tension pulley rotatably attached to the pulley arm, and the tension pulley as an auxiliary belt.
  • a tension adjusting device including an auto tensioner that urges the pulley arm in the pressing direction is used.
  • this hydraulic auto tensioner has a hydraulic damper mechanism that buffers the downward force applied to the rod from the accessory belt with the hydraulic oil inside the cylinder.
  • a hydraulic damper mechanism that buffers the downward force applied to the rod from the accessory belt with the hydraulic oil inside the cylinder.
  • an annular oil seal is attached to the inner periphery of the upper end opening of the cylinder so as to come into sliding contact with the movement of the rod.
  • the above hydraulic auto tensioner seals the hydraulic oil in the cylinder with an oil seal attached to the inner periphery of the upper end opening of the cylinder.
  • a hydraulic auto tensioner is used for a long period of time, a small amount of hydraulic oil leaks from the hydraulic auto tensioner, and the hydraulic leak may continue to adhere to the auxiliary belt and peripheral parts. It turned out to be. If the hydraulic oil adheres to the auxiliary belt and peripheral parts, it causes slippage of the auxiliary belt and malfunction of the peripheral parts.
  • the inventors of the present application investigated the cause of a small amount of hydraulic oil spilling and leaking from the hydraulic auto tensioner, and when the rod moves up and down according to the tension fluctuation of the auxiliary belt of the automobile, it accompanies the movement of the rod. It has been found that there is a phenomenon in which hydraulic oil is scraped out at the sliding contact portion of the oil seal, and the hydraulic oil oozes out from the hydraulic auto tensioner due to the scraping action.
  • the problem to be solved by the present invention is to provide a hydraulic auto tensioner that is unlikely to cause a phenomenon in which hydraulic oil oozes and leaks from the tensioner.
  • the present invention provides a hydraulic auto tensioner having the following configuration.
  • a cylinder with an open top and a closed bottom;
  • a rod inserted into the cylinder to be movable up and down;
  • a return spring for urging the rod upward;
  • a hydraulic damper mechanism for buffering downward force applied to the rod with hydraulic oil inside the cylinder;
  • a hydraulic auto tensioner provided with an annular oil seal attached to the inner periphery of the upper end opening of the cylinder so as to come into sliding contact with the movement of the rod,
  • a hydraulic auto tensioner wherein an oil absorber that absorbs hydraulic oil that oozes upward from the inside of the cylinder through the sliding contact portion of the oil seal is provided above the oil seal.
  • the oil absorber is an annular body arranged on the upper side of the annular oil seal.
  • the oil absorber is annular, the hydraulic oil that oozes out from any circumferential position of the sliding contact portion of the annular oil seal can be reliably absorbed. Therefore, even if the hydraulic auto tensioner is attached in any orientation, the leakage of hydraulic oil from the hydraulic auto tensioner can be prevented.
  • the oil absorber may be composed of a large number of fibers.
  • the oil absorber is preferably fixed on the upper side of the oil seal with an adhesive.
  • the hydraulic auto tensioner according to the present invention is an operation that oozes upward from the inside of the cylinder through the sliding contact portion of the oil seal when a working oil scraping action occurs at the sliding contact portion of the oil seal as the rod moves. Oil is absorbed by the oil absorber on the upper side of the oil seal. Therefore, even when the hydraulic auto tensioner is used for a long period of time, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner.
  • FIG. 2 The front view which shows the tension adjusting device incorporating the hydraulic auto tensioner of 1st Embodiment of this invention
  • Sectional view along the line II-II in FIG. 2 is an enlarged cross-sectional view near the oil seal of FIG.
  • FIG. 3 is an enlarged cross-sectional view showing a part of FIG.
  • Front view showing a tension adjusting apparatus incorporating a hydraulic auto tensioner according to a second embodiment of the present invention.
  • FIG. 1 shows a tension adjusting device incorporating a hydraulic auto tensioner 1 according to a first embodiment of the present invention.
  • the tension adjusting device includes a tension pulley 3 that contacts the belt 2, a pulley arm 4 that supports the tension pulley 3, and a hydraulic auto tensioner 1 that biases the pulley arm 4 in a direction to press the tension pulley 3 against the belt 2.
  • the belt 2 is an accessory belt that transmits rotation of a crankshaft (not shown) to an accessory such as an alternator or a water pump.
  • the lower connecting piece 5 of the hydraulic auto tensioner 1 is rotatably connected to an engine block 7 (see FIG. 2) via a lower connecting shaft 6.
  • the upper connecting piece 8 of the hydraulic auto tensioner 1 is rotatably connected to the pulley arm 4 via the upper connecting shaft 9.
  • the pulley arm 4 is supported so as to be swingable about a fulcrum shaft 10 fixed to the engine block 7.
  • the hydraulic auto tensioner 1 includes a cylinder 11, a rod 12 inserted in the cylinder 11 so as to be movable up and down, a spring seat 13 fixed to the upper end of the rod 12, and a spring seat 13.
  • a return spring 14 for urging the rod 12 upward a hydraulic damper mechanism 15 for buffering the downward force applied to the rod 12 with hydraulic oil inside the cylinder 11, and an inner periphery of the upper end opening of the cylinder 11.
  • the cylinder 11 is formed in a cylindrical shape with an upper end opened and a lower end closed.
  • a lower connecting piece 5 is integrally provided at the lower end of the cylinder 11.
  • the lower connecting piece 5 incorporates a bearing 17 that rotatably supports the lower connecting shaft 6.
  • a flange portion 18 that supports the lower end of the return spring 14 is integrally provided on the outer periphery of the cylinder 11.
  • the cylinder 11 is made of an aluminum alloy.
  • the hydraulic damper mechanism 15 includes a steel sleeve 19 fitted in the cylinder 11, a plunger 20 that is slidably inserted into the sleeve 19, and a pressure chamber 21 that is formed below the plunger 20.
  • the reservoir chamber 22 formed on the upper side of the plunger 20, the oil passage 23 communicating between the pressure chamber 21 and the reservoir chamber 22, and the flow of hydraulic oil from the reservoir chamber 22 side to the pressure chamber 21 side of the oil passage 23 Only a check valve 24 that permits only a leak, and a leak gap 25 formed between the sliding surfaces of the plunger 20 and the sleeve 19.
  • the pressure chamber 21 is filled with hydraulic oil, and the reservoir chamber 22 contains air and hydraulic oil in upper and lower layers.
  • the oil passage 23 is formed so as to penetrate the plunger 20 vertically.
  • the check valve 24 is disposed at the end of the oil passage 23 on the pressure chamber 21 side.
  • the size of the leak gap 25 is very small, and is set in a range of 0.015 to 0.080 mm as a difference in radius between the outer peripheral cylindrical surface of the plunger 20 and the inner peripheral cylindrical surface of the sleeve 19.
  • the plunger 20 is biased upward by a plunger spring 26 incorporated in the pressure chamber 21.
  • the plunger 20 supports the lower end of the rod 12, and when the rod 12 moves up and down, the plunger 20 moves up and down integrally with the rod 12.
  • a wear ring 27 is attached to the outer periphery of the insertion portion of the rod 12 into the cylinder 11.
  • the wear ring 27 is guided on the inner periphery of the cylinder 11 so that the position of the rod 12 does not deviate from the center of the cylinder 11.
  • the wear ring 27 is provided with a through hole 28 through which hydraulic oil passes.
  • the spring seat 13 includes an upper connecting piece 8 and a flange portion 29 formed on the outer periphery of the lower end of the upper connecting piece 8, and the flange portion 29 receives the upper end of the return spring 14.
  • the upper connecting piece 8 incorporates a bearing 30 that rotatably supports the upper connecting shaft 9.
  • the spring seat 13 has an outer cylindrical portion 31 extending downward from the flange portion 29 so as to face the outer diameter side of the cylinder 11.
  • the return spring 14 is a cylindrical coil spring having an inner diameter larger than the outer diameter of the cylinder 11, and is disposed coaxially on the outer diameter side of the cylinder 11.
  • a cylindrical seal fitting surface 32 having an inner diameter larger than the surface fitted to the sleeve 19 is formed on the inner periphery of the upper end opening of the cylinder 11.
  • the oil seal 16 is fitted with a tightening margin.
  • the oil seal 16 has a well-known configuration having a rubber lip that slidably contacts the outer periphery of the rod 12 as the rod 12 moves, and an annular metal core that supports the lip.
  • the oil seal 16 is restricted from moving upward by a retaining ring 33 attached to the inner periphery of the upper end opening of the cylinder 11.
  • An oil absorber 34 is fixed on the upper surface of the retaining ring 33.
  • the oil absorber 34 is an annular seat disposed above the annular oil seal 16.
  • the oil absorber 34 is composed of a large number of fibers. Recycled fibers (rayon, acetate, etc.) and natural fibers (cotton, silk, hemp, wool, etc.) can be used as the fibers, but synthetic resin fibers are preferably used. Examples of synthetic resin fibers include polyamide resins such as nylon, aromatic polyamide resins, polyethylene terephthalate, polyethylene naphthalate, polyethylene succinate, and polybutylene terephthalate. When synthetic resin fibers are used, the fibers can be prevented from swelling and dissolving with hydraulic oil, and the cost is low.
  • the oil absorber 34 is fixed to the upper surface of the retaining ring 33 with an adhesive 35.
  • the inner diameter side end of the oil absorber 34 protrudes more toward the inner diameter side than the inner diameter side end of the retaining ring 33.
  • the hydraulic auto tensioner 1 described above seals the hydraulic oil in the cylinder 11 with an oil seal 16 attached to the inner periphery of the upper end opening of the cylinder 11.
  • the hydraulic oil is scraped out at the sliding contact portion (the contact portion between the oil seal 16 and the rod 12) of the oil seal 16 as the rod 12 moves. May occur.
  • the tension of the belt 2 tends to be set low.
  • the load on the auxiliary machine driven by the belt 2 tends to increase.
  • the amplitude of the belt 2 tends to increase, and the expansion / contraction stroke of the hydraulic auto tensioner 1 tends to increase, so that the working oil is easily scraped out at the sliding contact portion of the oil seal 16.
  • the hydraulic auto tensioner 1 is used over a long period of time, the hydraulic oil scraped out at the sliding contact portion of the oil seal 16 leaks from the hydraulic auto tensioner 1 and continues to leak. May adhere to the belt 2 and peripheral parts.
  • the hydraulic oil adheres to the belt 2 and peripheral parts it causes slippage of the belt 2 and malfunction of peripheral parts.
  • the hydraulic auto tensioner 1 has a sliding contact portion of the oil seal 16 from the inside of the cylinder 11 when a hydraulic oil scraping action occurs in the sliding contact portion of the oil seal 16 as the rod 12 moves.
  • the hydraulic oil that oozes upward through the oil is absorbed by the oil absorber 34 on the upper side of the oil seal 16. Therefore, even when the hydraulic auto tensioner 1 is used over a long period of time, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner 1.
  • the hydraulic auto tensioner 1 employs the annular oil absorber 34, the hydraulic oil that oozes out from any circumferential position of the sliding contact portion of the annular oil seal 16 can be reliably absorbed. it can. For this reason, even if the hydraulic auto tensioner 1 is mounted in a posture inclined in any direction, it is possible to prevent leakage of hydraulic oil from the hydraulic auto tensioner 1.
  • the hydraulic auto tensioner 1 employs a structure composed of a large number of fibers, the amount of oil that can be absorbed by the oil absorber 34 is large. Therefore, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner 1 over a long period of time.
  • the oil absorber 34 is fixed with the adhesive 35, the oil absorber 34 is effectively prevented from falling off due to vibration applied to the hydraulic auto tensioner 1 from the outside. It is possible.
  • FIG. 5 and 6 show a hydraulic auto tensioner 1 according to a second embodiment of the present invention. Portions corresponding to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
  • the hydraulic damper mechanism 15 includes a steel sleeve 40 fixed in the cylinder 11 so as to be in sliding contact with the outer periphery of the rod 12, a pressure chamber 21 formed inside the sleeve 40, and a sleeve.
  • the size of the leak gap 25 is very small, and is set in a range of 0.015 to 0.080 mm as a radial difference between the cylindrical surface on the outer periphery of the rod 12 and the cylindrical surface on the inner periphery of the sleeve 40.
  • the sleeve 40 is coaxially inserted into the cylinder 11, and the lower outer periphery of the sleeve 40 is press-fitted into a sleeve fitting recess 42 formed on the inner bottom surface 41 of the cylinder 11.
  • the oil passage 23 is formed between the fitting surface of the sleeve fitting recess 42 and the sleeve 40.
  • the check valve 24 is press-fitted into the lower end of the sleeve 40.
  • the return spring 14 is a cylindrical coil spring having an outer diameter smaller than the inner diameter of the cylinder 11 and is coaxially disposed on the inner diameter side of the cylinder 11.
  • the lower end of the return spring 14 is supported by the inner bottom surface 41 of the cylinder 11, and the upper end of the return spring 14 presses the spring seat 13 upward.
  • the spring seat 13 includes an end plate 43 that receives the upper end of the return spring 14, an upper connecting piece 8 provided so as to protrude upward from the end plate 43, and an end plate 43 that faces the inner diameter side of the cylinder 11. It has an inner cylindrical portion 44 that extends downward, and an outer cylindrical portion 45 that extends downward from the end plate 43 so as to face the outer diameter side of the cylinder 11.
  • An oil seal 16 is fitted with an allowance on the inner periphery of the upper end opening of the cylinder 11.
  • the oil seal 16 has a known configuration including a rubber lip that is slidably contacted with the outer periphery of the inner cylindrical portion 44 as the rod 12 moves, and an annular metal core that supports the lip.
  • An annular oil absorber 34 is fixed to the upper surface of the oil seal 16.
  • the oil absorber 34 is composed of a large number of fibers. Recycled fibers (rayon, acetate, etc.) and natural fibers (cotton, silk, hemp, wool, etc.) can be used as the fibers, but synthetic resin fibers are preferably used.
  • the oil absorber 34 is fixed to the upper surface of the oil seal 16 with an adhesive 35.
  • the hydraulic auto tensioner 1 also slides the oil seal 16 from the inside of the cylinder 11 when a working oil scraping action occurs at the sliding contact portion of the oil seal 16 as the rod 12 moves.
  • the hydraulic oil that oozes upward through the contact portion (the contact portion between the oil seal 16 and the inner cylindrical portion 44) is absorbed by the oil absorber 34 on the upper side of the oil seal 16. Therefore, even when the hydraulic auto tensioner 1 is used over a long period of time, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner 1.
  • Other effects are the same as those of the first embodiment.

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  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
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Abstract

A hydraulic auto-tensioner (1) comprising a rod (12) inserted through a cylinder (11) so as to be capable of moving vertically, a return spring (14) that urges the rod (12) upward, a hydraulic damper mechanism (15) that uses hydraulic fluid inside the cylinder (11) to buffer downward force loaded onto the rod (12), and a ring-shaped oil seal (16) attached to the inner periphery of an upper-end opening in the cylinder (11) so as to slide against the inner periphery along with the movement of the rod (12), wherein the upper side of the oil seal (16) is provided with an oil absorber (34) for absorbing hydraulic fluid that has oozed upward out of the inside of the cylinder (11) through the sliding portion of the oil seal (16).

Description

油圧式オートテンショナHydraulic auto tensioner
　この発明は、作動油を用いて減衰力を発生する油圧式オートテンショナに関する。 This invention relates to a hydraulic auto tensioner that generates a damping force using hydraulic oil.
　自動車の補機、たとえばオルタネータやカーエアコンやウォータポンプなどは、その回転軸がエンジンのクランクシャフトに補機ベルトで連結され、その補機ベルトを介して駆動される。この補機ベルトの張力を適正範囲に保つために、一般に、支点軸を中心として揺動可能に設けたプーリアームと、そのプーリアームに回転可能に取り付けたテンションプーリと、そのテンションプーリを補機ベルトに押さえ付ける方向にプーリアームを付勢するオートテンショナとからなる張力調整装置が使用される。 Automobile accessories, such as alternators, car air conditioners, and water pumps, are connected to the engine crankshaft by an accessory belt and driven through the accessory belt. In order to keep the tension of the auxiliary belt within an appropriate range, generally, a pulley arm provided so as to be swingable about a fulcrum shaft, a tension pulley rotatably attached to the pulley arm, and the tension pulley as an auxiliary belt. A tension adjusting device including an auto tensioner that urges the pulley arm in the pressing direction is used.
　この張力調整装置に組み込まれる油圧式オートテンショナとして、例えば、下記特許文献１，２に記載のものが知られている。これらの油圧式オートテンショナは、上端が開口し、下端が閉塞したシリンダと、そのシリンダに上下に移動可能に挿入されたロッドと、そのロッドを上方に付勢するリターンスプリングとを有し、補機ベルトの張力が変動すると、その補機ベルトの張力とリターンスプリングの付勢力がつりあう位置までロッドが移動して補機ベルトの張力変動を吸収する。 As a hydraulic auto tensioner incorporated in this tension adjusting device, for example, those described in Patent Documents 1 and 2 below are known. These hydraulic auto tensioners have a cylinder with an open upper end and a closed lower end, a rod inserted into the cylinder so as to be movable up and down, and a return spring that urges the rod upward. When the tension of the machine belt fluctuates, the rod moves to a position where the tension of the auxiliary machine belt and the biasing force of the return spring balance, and absorbs the fluctuation of the tension of the machine belt.
　また、この油圧式オートテンショナは、補機ベルトからロッドに負荷される下向きの力を、シリンダの内部の作動油で緩衝する油圧ダンパ機構を有する。また、油圧ダンパ機構の作動油をシリンダ内に密封するため、シリンダの上端開口の内周には、ロッドの移動に伴って摺接する環状のオイルシールが取り付けられている。 Also, this hydraulic auto tensioner has a hydraulic damper mechanism that buffers the downward force applied to the rod from the accessory belt with the hydraulic oil inside the cylinder. In addition, in order to seal the hydraulic oil of the hydraulic damper mechanism in the cylinder, an annular oil seal is attached to the inner periphery of the upper end opening of the cylinder so as to come into sliding contact with the movement of the rod.
特許第５５７４２２９号公報Japanese Patent No. 5574229 特開２０１２－２２５４４７号公報JP 2012-225447 A
　上記の油圧式オートテンショナは、シリンダの上端開口の内周に取り付けたオイルシールで、シリンダ内の作動油を密封している。ところが、長期にわたって油圧式オートテンショナを使用したときに、油圧式オートテンショナから微量の作動油がにじみ漏れ、そのにじみ漏れが継続することで、作動油が補機ベルトや周辺部品に付着する場合があることが判明した。作動油が補機ベルトや周辺部品に付着すると、補機ベルトの滑りや周辺部品の動作不良の原因となる。 The above hydraulic auto tensioner seals the hydraulic oil in the cylinder with an oil seal attached to the inner periphery of the upper end opening of the cylinder. However, when a hydraulic auto tensioner is used for a long period of time, a small amount of hydraulic oil leaks from the hydraulic auto tensioner, and the hydraulic leak may continue to adhere to the auxiliary belt and peripheral parts. It turned out to be. If the hydraulic oil adheres to the auxiliary belt and peripheral parts, it causes slippage of the auxiliary belt and malfunction of the peripheral parts.
　そこで、本願の発明者が、油圧式オートテンショナから微量の作動油がにじみ漏れる原因を調査したところ、自動車の補機ベルトの張力変動に応じてロッドが上下に移動するとき、ロッドの移動に伴うオイルシールの摺接部分で作動油の掻き出し作用が生じ、その掻き出し作用によって作動油が油圧式オートテンショナからにじみ漏れる現象が起きていることを見出した。 Therefore, the inventors of the present application investigated the cause of a small amount of hydraulic oil spilling and leaking from the hydraulic auto tensioner, and when the rod moves up and down according to the tension fluctuation of the auxiliary belt of the automobile, it accompanies the movement of the rod. It has been found that there is a phenomenon in which hydraulic oil is scraped out at the sliding contact portion of the oil seal, and the hydraulic oil oozes out from the hydraulic auto tensioner due to the scraping action.
　特に、近年、車両の低燃費化を図るため、補機ベルトの低フリクション化が求められており、これに伴い、補機ベルトの張力も低く設定される傾向にある。その一方で、補機ベルトで駆動される補機の負荷は、増加する傾向にある。そのため、補機ベルトの振幅が大きくなりやすく、油圧式オートテンショナの伸縮ストロークも大きくなる傾向にあり、オイルシールの摺接部分で作動油の掻き出し作用が生じやすくなっている。 In particular, in recent years, in order to reduce the fuel consumption of vehicles, there has been a demand for lower friction of auxiliary belts, and accordingly, the tension of auxiliary belts tends to be set low. On the other hand, the load on the auxiliary machine driven by the auxiliary machine belt tends to increase. For this reason, the amplitude of the auxiliary machine belt tends to increase, and the expansion / contraction stroke of the hydraulic auto tensioner tends to increase, so that the working oil is easily scraped out at the sliding contact portion of the oil seal.
　この発明が解決しようとする課題は、テンショナから作動油がにじみ漏れる現象が生じにくい油圧式オートテンショナを提供することである。 The problem to be solved by the present invention is to provide a hydraulic auto tensioner that is unlikely to cause a phenomenon in which hydraulic oil oozes and leaks from the tensioner.
　上記課題を解決するため、この発明では、以下の構成の油圧式オートテンショナを提供する。
　上端が開口し、下端が閉塞したシリンダと、
　前記シリンダに上下に移動可能に挿入されたロッドと、
　前記ロッドを上方に付勢するリターンスプリングと、
　前記ロッドに負荷される下向きの力を前記シリンダの内部の作動油で緩衝する油圧ダンパ機構と、
　前記ロッドの移動に伴って摺接するように前記シリンダの上端開口の内周に取り付けられた環状のオイルシールと、を備える油圧式オートテンショナにおいて、
　前記シリンダの内部から前記オイルシールの摺接部分を通って上方ににじみ出た作動油を吸収するオイル吸収体を前記オイルシールの上側に設けたことを特徴とする油圧式オートテンショナ。 In order to solve the above problems, the present invention provides a hydraulic auto tensioner having the following configuration.
A cylinder with an open top and a closed bottom;
A rod inserted into the cylinder to be movable up and down;
A return spring for urging the rod upward;
A hydraulic damper mechanism for buffering downward force applied to the rod with hydraulic oil inside the cylinder;
In a hydraulic auto tensioner provided with an annular oil seal attached to the inner periphery of the upper end opening of the cylinder so as to come into sliding contact with the movement of the rod,
A hydraulic auto tensioner, wherein an oil absorber that absorbs hydraulic oil that oozes upward from the inside of the cylinder through the sliding contact portion of the oil seal is provided above the oil seal.
　このようにすると、ロッドの移動に伴うオイルシールの摺接部分で作動油の掻き出し作用が生じたときに、シリンダの内部からオイルシールの摺接部分を通って上方ににじみ出た作動油は、オイルシールの上側のオイル吸収体で吸収される。そのため、長期にわたって油圧式オートテンショナを使用したときにも、油圧式オートテンショナからの作動油のにじみ漏れを防止することができる。 In this way, when the hydraulic oil scraping action occurs at the sliding contact portion of the oil seal due to the movement of the rod, the hydraulic oil that oozes out from the inside of the cylinder through the sliding contact portion of the oil seal It is absorbed by the oil absorber on the upper side of the seal. Therefore, even when the hydraulic auto tensioner is used for a long period of time, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner.
　前記オイル吸収体は、環状の前記オイルシールの上側に配置された環状体を採用すると好ましい。 It is preferable that the oil absorber is an annular body arranged on the upper side of the annular oil seal.
　このようにすると、オイル吸収体が環状なので、環状のオイルシールの摺接部分のいずれの周方向位置からにじみ出た作動油も確実に吸収することができる。そのため、油圧式オートテンショナをいずれの方向に傾けた姿勢で取り付けても、油圧式オートテンショナからの作動油のにじみ漏れを防止することができる。 In this case, since the oil absorber is annular, the hydraulic oil that oozes out from any circumferential position of the sliding contact portion of the annular oil seal can be reliably absorbed. Therefore, even if the hydraulic auto tensioner is attached in any orientation, the leakage of hydraulic oil from the hydraulic auto tensioner can be prevented.
　前記オイル吸収体は、多数の繊維で構成されたものを採用することができる。 The oil absorber may be composed of a large number of fibers.
　このようにすると、オイル吸収体で吸収可能なオイルの量が多いため、長期にわたり、油圧式オートテンショナからの作動油のにじみ漏れを防止することができる。 In this case, since the amount of oil that can be absorbed by the oil absorber is large, it is possible to prevent leakage of hydraulic oil from the hydraulic auto tensioner over a long period of time.
　前記繊維として、合成樹脂繊維を用いると好ましい。 It is preferable to use a synthetic resin fiber as the fiber.
　このようにすると、作動油による繊維の膨潤や溶解を防止することができる。 In this way, the swelling and dissolution of the fiber due to the hydraulic oil can be prevented.
　前記オイル吸収体は、前記オイルシールの上側に接着剤で固定すると好ましい。 The oil absorber is preferably fixed on the upper side of the oil seal with an adhesive.
　このようにすると、外部から油圧式オートテンショナに加わる振動によってオイル吸収体が脱落するのを効果的に防止することが可能となる。 This makes it possible to effectively prevent the oil absorber from falling off due to vibration applied to the hydraulic auto tensioner from the outside.
　この発明の油圧式オートテンショナは、ロッドの移動に伴うオイルシールの摺接部分で作動油の掻き出し作用が生じたときに、シリンダの内部からオイルシールの摺接部分を通って上方ににじみ出た作動油を、オイルシールの上側のオイル吸収体で吸収する。そのため、長期にわたって油圧式オートテンショナを使用したときにも、油圧式オートテンショナからの作動油のにじみ漏れを防止することができる。 The hydraulic auto tensioner according to the present invention is an operation that oozes upward from the inside of the cylinder through the sliding contact portion of the oil seal when a working oil scraping action occurs at the sliding contact portion of the oil seal as the rod moves. Oil is absorbed by the oil absorber on the upper side of the oil seal. Therefore, even when the hydraulic auto tensioner is used for a long period of time, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner.
この発明の第１実施形態の油圧式オートテンショナを組み込んだ張力調整装置を示す正面図The front view which shows the tension adjusting device incorporating the hydraulic auto tensioner of 1st Embodiment of this invention 図１のII－II線に沿った断面図Sectional view along the line II-II in FIG. 図２のオイルシール近傍の拡大断面図2 is an enlarged cross-sectional view near the oil seal of FIG. 図３の一部をさらに拡大して示す拡大断面図FIG. 3 is an enlarged cross-sectional view showing a part of FIG. この発明の第２実施形態の油圧式オートテンショナを組み込んだ張力調整装置を示す正面図Front view showing a tension adjusting apparatus incorporating a hydraulic auto tensioner according to a second embodiment of the present invention. 図５のVI－VI線に沿った断面図Sectional view along line VI-VI in FIG.
　図１に、この発明の第１実施形態の油圧式オートテンショナ１を組み込んだ張力調整装置を示す。この張力調整装置は、ベルト２に接触するテンションプーリ３と、テンションプーリ３を支持するプーリアーム４と、テンションプーリ３をベルト２に押さえ付ける方向にプーリアーム４を付勢する油圧式オートテンショナ１とを有する。ベルト２は、図示しないクランクシャフトの回転をオルタネータやウォータポンプ等の補機に伝達する補機ベルトである。 FIG. 1 shows a tension adjusting device incorporating a hydraulic auto tensioner 1 according to a first embodiment of the present invention. The tension adjusting device includes a tension pulley 3 that contacts the belt 2, a pulley arm 4 that supports the tension pulley 3, and a hydraulic auto tensioner 1 that biases the pulley arm 4 in a direction to press the tension pulley 3 against the belt 2. Have. The belt 2 is an accessory belt that transmits rotation of a crankshaft (not shown) to an accessory such as an alternator or a water pump.
　油圧式オートテンショナ１の下部連結片５は下部連結軸６を介してエンジンブロック７（図２参照）に回動可能に連結されている。油圧式オートテンショナ１の上部連結片８は上部連結軸９を介してプーリアーム４に回動可能に連結されている。プーリアーム４は、エンジンブロック７に固定された支点軸１０を中心に揺動可能に支持されている。 The lower connecting piece 5 of the hydraulic auto tensioner 1 is rotatably connected to an engine block 7 (see FIG. 2) via a lower connecting shaft 6. The upper connecting piece 8 of the hydraulic auto tensioner 1 is rotatably connected to the pulley arm 4 via the upper connecting shaft 9. The pulley arm 4 is supported so as to be swingable about a fulcrum shaft 10 fixed to the engine block 7.
　図２に示すように、油圧式オートテンショナ１は、シリンダ１１と、シリンダ１１に上下に移動可能に挿入されたロッド１２と、ロッド１２の上端に固定されたばね座１３と、ばね座１３を介してロッド１２を上方に付勢するリターンスプリング１４と、ロッド１２に負荷される下向きの力をシリンダ１１の内部の作動油で緩衝する油圧ダンパ機構１５と、シリンダ１１の上端開口の内周に取り付けられた環状のオイルシール１６とを有する。 As shown in FIG. 2, the hydraulic auto tensioner 1 includes a cylinder 11, a rod 12 inserted in the cylinder 11 so as to be movable up and down, a spring seat 13 fixed to the upper end of the rod 12, and a spring seat 13. A return spring 14 for urging the rod 12 upward, a hydraulic damper mechanism 15 for buffering the downward force applied to the rod 12 with hydraulic oil inside the cylinder 11, and an inner periphery of the upper end opening of the cylinder 11. And an annular oil seal 16.
　シリンダ１１は、上端が開口し、下端が閉塞した筒状に形成されている。シリンダ１１の下端には、下部連結片５が一体に設けられている。下部連結片５には、下部連結軸６を回動可能に支持する軸受１７が組み込まれている。シリンダ１１の外周には、リターンスプリング１４の下端を支持するフランジ部１８が一体に設けられている。シリンダ１１は、アルミ合金で形成されている。 The cylinder 11 is formed in a cylindrical shape with an upper end opened and a lower end closed. A lower connecting piece 5 is integrally provided at the lower end of the cylinder 11. The lower connecting piece 5 incorporates a bearing 17 that rotatably supports the lower connecting shaft 6. A flange portion 18 that supports the lower end of the return spring 14 is integrally provided on the outer periphery of the cylinder 11. The cylinder 11 is made of an aluminum alloy.
　油圧ダンパ機構１５は、シリンダ１１内に嵌め込まれた鋼製のスリーブ１９と、スリーブ１９内に上下に摺動可能に挿入されたプランジャ２０と、プランジャ２０の下側に形成された圧力室２１と、プランジャ２０の上側に形成されたリザーバ室２２と、圧力室２１とリザーバ室２２の間を連通する油通路２３と、油通路２３のリザーバ室２２側から圧力室２１側への作動油の流れのみを許容するチェックバルブ２４と、プランジャ２０とスリーブ１９の摺動面間に形成されたリーク隙間２５とからなる。 The hydraulic damper mechanism 15 includes a steel sleeve 19 fitted in the cylinder 11, a plunger 20 that is slidably inserted into the sleeve 19, and a pressure chamber 21 that is formed below the plunger 20. The reservoir chamber 22 formed on the upper side of the plunger 20, the oil passage 23 communicating between the pressure chamber 21 and the reservoir chamber 22, and the flow of hydraulic oil from the reservoir chamber 22 side to the pressure chamber 21 side of the oil passage 23 Only a check valve 24 that permits only a leak, and a leak gap 25 formed between the sliding surfaces of the plunger 20 and the sleeve 19.
　圧力室２１は、作動油で満たされ、リザーバ室２２には、空気と作動油が上下二層に収容されている。油通路２３は、プランジャ２０の内部を上下に貫通して形成されている。チェックバルブ２４は、油通路２３の圧力室２１側の端部に配置されている。リーク隙間２５の大きさは微小であり、プランジャ２０の外周の円筒面とスリーブ１９の内周の円筒面の半径差で０．０１５～０．０８０ｍｍの範囲に設定されている。プランジャ２０は、圧力室２１に組み込まれたプランジャスプリング２６で上方に付勢されている。プランジャ２０はロッド１２の下端を支持しており、ロッド１２が上下に移動するとき、そのロッド１２と一体にプランジャ２０が上下に移動するようになっている。 The pressure chamber 21 is filled with hydraulic oil, and the reservoir chamber 22 contains air and hydraulic oil in upper and lower layers. The oil passage 23 is formed so as to penetrate the plunger 20 vertically. The check valve 24 is disposed at the end of the oil passage 23 on the pressure chamber 21 side. The size of the leak gap 25 is very small, and is set in a range of 0.015 to 0.080 mm as a difference in radius between the outer peripheral cylindrical surface of the plunger 20 and the inner peripheral cylindrical surface of the sleeve 19. The plunger 20 is biased upward by a plunger spring 26 incorporated in the pressure chamber 21. The plunger 20 supports the lower end of the rod 12, and when the rod 12 moves up and down, the plunger 20 moves up and down integrally with the rod 12.
　ロッド１２のシリンダ１１内への挿入部分の外周には、ウェアリング２７が取り付けられている。ウェアリング２７は、ロッド１２の位置がシリンダ１１の中心からずれないようにシリンダ１１の内周で案内されている。ウェアリング２７には、作動油を通過させる貫通孔２８が設けられている。 A wear ring 27 is attached to the outer periphery of the insertion portion of the rod 12 into the cylinder 11. The wear ring 27 is guided on the inner periphery of the cylinder 11 so that the position of the rod 12 does not deviate from the center of the cylinder 11. The wear ring 27 is provided with a through hole 28 through which hydraulic oil passes.
　ばね座１３は、上部連結片８と、上部連結片８の下端外周に形成されたフランジ部２９とを有し、そのフランジ部２９でリターンスプリング１４の上端を受けている。上部連結片８には、上部連結軸９を回動可能に支持する軸受３０が組み込まれている。また、ばね座１３には、シリンダ１１の外径側に対向するようにフランジ部２９から下方に延びる外側円筒部３１を有する。リターンスプリング１４は、シリンダ１１の外径よりも大きい内径をもつ円筒コイルばねであり、シリンダ１１の外径側に同軸に配置されている。 The spring seat 13 includes an upper connecting piece 8 and a flange portion 29 formed on the outer periphery of the lower end of the upper connecting piece 8, and the flange portion 29 receives the upper end of the return spring 14. The upper connecting piece 8 incorporates a bearing 30 that rotatably supports the upper connecting shaft 9. Further, the spring seat 13 has an outer cylindrical portion 31 extending downward from the flange portion 29 so as to face the outer diameter side of the cylinder 11. The return spring 14 is a cylindrical coil spring having an inner diameter larger than the outer diameter of the cylinder 11, and is disposed coaxially on the outer diameter side of the cylinder 11.
　図３に示すように、シリンダ１１の上端開口の内周には、スリーブ１９と嵌合する面よりも大きい内径を有する円筒状のシール嵌合面３２が形成され、そのシール嵌合面３２にオイルシール１６が締め代をもって嵌合している。オイルシール１６は、ロッド１２の移動に伴ってロッド１２の外周に摺接するゴム製のリップと、そのリップを支持する環状の芯金とを有する周知の構成のものである。オイルシール１６は、シリンダ１１の上端開口の内周に装着した止め輪３３で上方への移動が規制されている。 As shown in FIG. 3, a cylindrical seal fitting surface 32 having an inner diameter larger than the surface fitted to the sleeve 19 is formed on the inner periphery of the upper end opening of the cylinder 11. The oil seal 16 is fitted with a tightening margin. The oil seal 16 has a well-known configuration having a rubber lip that slidably contacts the outer periphery of the rod 12 as the rod 12 moves, and an annular metal core that supports the lip. The oil seal 16 is restricted from moving upward by a retaining ring 33 attached to the inner periphery of the upper end opening of the cylinder 11.
　止め輪３３の上面には、オイル吸収体３４が固定されている。オイル吸収体３４は、環状のオイルシール１６の上側に配置された環状のシートである。オイル吸収体３４は、多数の繊維で構成されている。繊維は、再生繊維（レーヨン、アセテートなど）や天然繊維（綿、絹、麻、羊毛など）を用いることができるが、合成樹脂繊維を用いると好ましい。合成樹脂繊維としては、ナイロンなどのポリアミド樹脂、芳香族ポリアミド樹脂、ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリエチレンサクシネート、ポリブチレンテレフタレートなどのポリエステル樹脂が挙げられる。合成樹脂繊維を用いると、作動油による繊維の膨潤や溶解を防止することができ、かつ低コストである。 An oil absorber 34 is fixed on the upper surface of the retaining ring 33. The oil absorber 34 is an annular seat disposed above the annular oil seal 16. The oil absorber 34 is composed of a large number of fibers. Recycled fibers (rayon, acetate, etc.) and natural fibers (cotton, silk, hemp, wool, etc.) can be used as the fibers, but synthetic resin fibers are preferably used. Examples of synthetic resin fibers include polyamide resins such as nylon, aromatic polyamide resins, polyethylene terephthalate, polyethylene naphthalate, polyethylene succinate, and polybutylene terephthalate. When synthetic resin fibers are used, the fibers can be prevented from swelling and dissolving with hydraulic oil, and the cost is low.
　図４に示すように、オイル吸収体３４は、止め輪３３の上面に接着剤３５で固定されている。オイル吸収体３４の内径側端部は、止め輪３３の内径側端部よりも内径側に突出している。 As shown in FIG. 4, the oil absorber 34 is fixed to the upper surface of the retaining ring 33 with an adhesive 35. The inner diameter side end of the oil absorber 34 protrudes more toward the inner diameter side than the inner diameter side end of the retaining ring 33.
　次に、この油圧式オートテンショナ１の動作例を説明する。 Next, an operation example of the hydraulic auto tensioner 1 will be described.
　図１に示すベルト２の張力が小さくなると、リターンスプリング１４の付勢力によって、ロッド１２がスリーブ１９から突出する方向にロッド１２が移動し、ベルト２の弛みを吸収する。このとき、図２に示す圧力室２１の容積が拡大するので、チェックバルブ２４が開き、リザーバ室２２内の作動油が油通路２３を通って圧力室２１に流入する。 When the tension of the belt 2 shown in FIG. 1 decreases, the rod 12 moves in a direction in which the rod 12 protrudes from the sleeve 19 due to the urging force of the return spring 14, and the slack of the belt 2 is absorbed. At this time, since the volume of the pressure chamber 21 shown in FIG. 2 is enlarged, the check valve 24 is opened, and the hydraulic oil in the reservoir chamber 22 flows into the pressure chamber 21 through the oil passage 23.
　一方、図１に示すベルト２の張力が大きくなると、そのベルト２の張力によって、ロッド１２がスリーブ１９内に押し込まれる方向にロッド１２が移動し、ベルト２の緊張を吸収する。このとき、図２に示す圧力室２１の容積が縮小するので、チェックバルブ２４が閉じ、圧力室２１内の作動油がリーク隙間２５を通って流出し、その作動油の粘性抵抗によってダンパ作用を生じる。 On the other hand, when the tension of the belt 2 shown in FIG. 1 increases, the rod 12 moves in the direction in which the rod 12 is pushed into the sleeve 19 due to the tension of the belt 2, and the tension of the belt 2 is absorbed. At this time, since the volume of the pressure chamber 21 shown in FIG. 2 is reduced, the check valve 24 is closed, the hydraulic oil in the pressure chamber 21 flows out through the leak gap 25, and the damper action is performed by the viscous resistance of the hydraulic oil. Arise.
　ところで、上記の油圧式オートテンショナ１は、シリンダ１１の上端開口の内周に取り付けたオイルシール１６で、シリンダ１１内の作動油を密封している。ここで、ベルト２の張力変動に応じてロッド１２が上下に移動するとき、ロッド１２の移動に伴うオイルシール１６の摺接部分（オイルシール１６とロッド１２の接触部分）で作動油の掻き出し作用が生じることがある。特に、近年、車両の低燃費化を図るため、ベルト２の低フリクション化が求められており、これに伴い、ベルト２の張力も低く設定される傾向にある。その一方で、ベルト２で駆動される補機の負荷は、増加する傾向にある。そのため、ベルト２の振幅が大きくなりやすく、油圧式オートテンショナ１の伸縮ストロークも大きくなる傾向にあり、オイルシール１６の摺接部分で作動油の掻き出し作用が生じやすくなっている。そして、長期にわたって油圧式オートテンショナ１を使用したときに、オイルシール１６の摺接部分で掻き出された作動油が油圧式オートテンショナ１からにじみ漏れ、そのにじみ漏れが継続することで、作動油がベルト２や周辺部品に付着する可能性がある。作動油がベルト２や周辺部品に付着すると、ベルト２の滑りや周辺部品の動作不良の原因となる。 By the way, the hydraulic auto tensioner 1 described above seals the hydraulic oil in the cylinder 11 with an oil seal 16 attached to the inner periphery of the upper end opening of the cylinder 11. Here, when the rod 12 moves up and down according to the tension fluctuation of the belt 2, the hydraulic oil is scraped out at the sliding contact portion (the contact portion between the oil seal 16 and the rod 12) of the oil seal 16 as the rod 12 moves. May occur. In particular, in recent years, there has been a demand for low friction of the belt 2 in order to reduce the fuel consumption of the vehicle, and accordingly, the tension of the belt 2 tends to be set low. On the other hand, the load on the auxiliary machine driven by the belt 2 tends to increase. Therefore, the amplitude of the belt 2 tends to increase, and the expansion / contraction stroke of the hydraulic auto tensioner 1 tends to increase, so that the working oil is easily scraped out at the sliding contact portion of the oil seal 16. When the hydraulic auto tensioner 1 is used over a long period of time, the hydraulic oil scraped out at the sliding contact portion of the oil seal 16 leaks from the hydraulic auto tensioner 1 and continues to leak. May adhere to the belt 2 and peripheral parts. When the hydraulic oil adheres to the belt 2 and peripheral parts, it causes slippage of the belt 2 and malfunction of peripheral parts.
　この問題に対し、この油圧式オートテンショナ１は、ロッド１２の移動に伴うオイルシール１６の摺接部分で作動油の掻き出し作用が生じたときに、シリンダ１１の内部からオイルシール１６の摺接部分を通って上方ににじみ出た作動油を、オイルシール１６の上側のオイル吸収体３４で吸収する。そのため、長期にわたって油圧式オートテンショナ１を使用したときにも、油圧式オートテンショナ１からの作動油のにじみ漏れを防止することができる。 In response to this problem, the hydraulic auto tensioner 1 has a sliding contact portion of the oil seal 16 from the inside of the cylinder 11 when a hydraulic oil scraping action occurs in the sliding contact portion of the oil seal 16 as the rod 12 moves. The hydraulic oil that oozes upward through the oil is absorbed by the oil absorber 34 on the upper side of the oil seal 16. Therefore, even when the hydraulic auto tensioner 1 is used over a long period of time, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner 1.
　また、この油圧式オートテンショナ１は、環状のオイル吸収体３４を採用しているので、環状のオイルシール１６の摺接部分のいずれの周方向位置からにじみ出た作動油も確実に吸収することができる。そのため、油圧式オートテンショナ１をいずれの方向に傾けた姿勢で取り付けても、油圧式オートテンショナ１からの作動油のにじみ漏れを防止することができる。 In addition, since the hydraulic auto tensioner 1 employs the annular oil absorber 34, the hydraulic oil that oozes out from any circumferential position of the sliding contact portion of the annular oil seal 16 can be reliably absorbed. it can. For this reason, even if the hydraulic auto tensioner 1 is mounted in a posture inclined in any direction, it is possible to prevent leakage of hydraulic oil from the hydraulic auto tensioner 1.
　また、この油圧式オートテンショナ１は、多数の繊維で構成されたものを採用しているので、オイル吸収体３４で吸収可能なオイルの量が多い。そのため、長期にわたり、油圧式オートテンショナ１からの作動油のにじみ漏れを防止することができる。 Further, since the hydraulic auto tensioner 1 employs a structure composed of a large number of fibers, the amount of oil that can be absorbed by the oil absorber 34 is large. Therefore, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner 1 over a long period of time.
　また、この油圧式オートテンショナ１は、オイル吸収体３４を接着剤３５で固定しているので、外部から油圧式オートテンショナ１に加わる振動によってオイル吸収体３４が脱落するのを効果的に防止することが可能となっている。 Further, in the hydraulic auto tensioner 1, since the oil absorber 34 is fixed with the adhesive 35, the oil absorber 34 is effectively prevented from falling off due to vibration applied to the hydraulic auto tensioner 1 from the outside. It is possible.
　図５、図６に、この発明の第２実施形態の油圧式オートテンショナ１を示す。第１実施形態に対応する部分は同一の符号を付して説明を省略する。 5 and 6 show a hydraulic auto tensioner 1 according to a second embodiment of the present invention. Portions corresponding to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
　図６に示すように、油圧ダンパ機構１５は、ロッド１２の外周に摺接するようにシリンダ１１内に固定された鋼製のスリーブ４０と、スリーブ４０の内側に形成された圧力室２１と、スリーブ４０とシリンダ１１の間に形成されたリザーバ室２２と、圧力室２１とリザーバ室２２の間を連通する油通路２３と、油通路２３のリザーバ室２２側から圧力室２１側への作動油の流れのみを許容するチェックバルブ２４と、ロッド１２とスリーブ４０の摺動面間に形成されたリーク隙間２５とからなる。リーク隙間２５の大きさは微小であり、ロッド１２の外周の円筒面とスリーブ４０の内周の円筒面の半径差で０．０１５～０．０８０ｍｍの範囲に設定されている。 As shown in FIG. 6, the hydraulic damper mechanism 15 includes a steel sleeve 40 fixed in the cylinder 11 so as to be in sliding contact with the outer periphery of the rod 12, a pressure chamber 21 formed inside the sleeve 40, and a sleeve. The reservoir chamber 22 formed between the cylinder 40 and the cylinder 11, the oil passage 23 communicating between the pressure chamber 21 and the reservoir chamber 22, and the hydraulic oil from the reservoir chamber 22 side of the oil passage 23 to the pressure chamber 21 side. It consists of a check valve 24 that allows only flow and a leak gap 25 formed between the sliding surfaces of the rod 12 and the sleeve 40. The size of the leak gap 25 is very small, and is set in a range of 0.015 to 0.080 mm as a radial difference between the cylindrical surface on the outer periphery of the rod 12 and the cylindrical surface on the inner periphery of the sleeve 40.
　スリーブ４０はシリンダ１１内に同軸に挿入され、そのスリーブ４０の下部外周が、シリンダ１１の内底面４１に形成されたスリーブ嵌合凹部４２に圧入されている。油通路２３は、スリーブ嵌合凹部４２とスリーブ４０の嵌合面間に形成されている。チェックバルブ２４は、スリーブ４０の下端に圧入されている。 The sleeve 40 is coaxially inserted into the cylinder 11, and the lower outer periphery of the sleeve 40 is press-fitted into a sleeve fitting recess 42 formed on the inner bottom surface 41 of the cylinder 11. The oil passage 23 is formed between the fitting surface of the sleeve fitting recess 42 and the sleeve 40. The check valve 24 is press-fitted into the lower end of the sleeve 40.
　リターンスプリング１４は、シリンダ１１の内径よりも小さい外径をもつ円筒コイルばねであり、シリンダ１１の内径側に同軸に配置されている。リターンスプリング１４の下端はシリンダ１１の内底面４１で支持され、リターンスプリング１４の上端はばね座１３を上方に押圧している。 The return spring 14 is a cylindrical coil spring having an outer diameter smaller than the inner diameter of the cylinder 11 and is coaxially disposed on the inner diameter side of the cylinder 11. The lower end of the return spring 14 is supported by the inner bottom surface 41 of the cylinder 11, and the upper end of the return spring 14 presses the spring seat 13 upward.
　ばね座１３は、リターンスプリング１４の上端を受ける端板４３と、端板４３から上方に突出するように設けられた上部連結片８と、シリンダ１１の内径側に対向するように端板４３から下方に延びる内側円筒部４４と、シリンダ１１の外径側に対向するように端板４３から下方に延びる外側円筒部４５とを有する。 The spring seat 13 includes an end plate 43 that receives the upper end of the return spring 14, an upper connecting piece 8 provided so as to protrude upward from the end plate 43, and an end plate 43 that faces the inner diameter side of the cylinder 11. It has an inner cylindrical portion 44 that extends downward, and an outer cylindrical portion 45 that extends downward from the end plate 43 so as to face the outer diameter side of the cylinder 11.
　シリンダ１１の上端開口の内周には、オイルシール１６が締め代をもって嵌合している。オイルシール１６は、ロッド１２の移動に伴って内側円筒部４４の外周に摺接するゴム製のリップと、そのリップを支持する環状の芯金とを有する周知の構成のものである。 ∙ An oil seal 16 is fitted with an allowance on the inner periphery of the upper end opening of the cylinder 11. The oil seal 16 has a known configuration including a rubber lip that is slidably contacted with the outer periphery of the inner cylindrical portion 44 as the rod 12 moves, and an annular metal core that supports the lip.
　オイルシール１６の上面には、環状のオイル吸収体３４が固定されている。オイル吸収体３４は、多数の繊維で構成されている。繊維は、再生繊維（レーヨン、アセテートなど）や天然繊維（綿、絹、麻、羊毛など）を用いることができるが、合成樹脂繊維を用いると好ましい。オイル吸収体３４は、オイルシール１６の上面に接着剤３５で固定されている。 An annular oil absorber 34 is fixed to the upper surface of the oil seal 16. The oil absorber 34 is composed of a large number of fibers. Recycled fibers (rayon, acetate, etc.) and natural fibers (cotton, silk, hemp, wool, etc.) can be used as the fibers, but synthetic resin fibers are preferably used. The oil absorber 34 is fixed to the upper surface of the oil seal 16 with an adhesive 35.
　この油圧式オートテンショナ１も、第１実施形態と同様、ロッド１２の移動に伴うオイルシール１６の摺接部分で作動油の掻き出し作用が生じたときに、シリンダ１１の内部からオイルシール１６の摺接部分（オイルシール１６と内側円筒部４４の接触部分）を通って上方ににじみ出た作動油を、オイルシール１６の上側のオイル吸収体３４で吸収する。そのため、長期にわたって油圧式オートテンショナ１を使用したときにも、油圧式オートテンショナ１からの作動油のにじみ漏れを防止することができる。その他も作用効果も第１実施形態と同様である。 Similarly to the first embodiment, the hydraulic auto tensioner 1 also slides the oil seal 16 from the inside of the cylinder 11 when a working oil scraping action occurs at the sliding contact portion of the oil seal 16 as the rod 12 moves. The hydraulic oil that oozes upward through the contact portion (the contact portion between the oil seal 16 and the inner cylindrical portion 44) is absorbed by the oil absorber 34 on the upper side of the oil seal 16. Therefore, even when the hydraulic auto tensioner 1 is used over a long period of time, it is possible to prevent the leakage of hydraulic oil from the hydraulic auto tensioner 1. Other effects are the same as those of the first embodiment.
　今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
１　　　　油圧式オートテンショナ
１１　　　シリンダ
１２　　　ロッド
１４　　　リターンスプリング
１５　　　油圧ダンパ機構
１６　　　オイルシール
３５　　　接着剤
３４　　　オイル吸収体 1 Hydraulic Auto Tensioner 11 Cylinder 12 Rod 14 Return Spring 15 Hydraulic Damper Mechanism 16 Oil Seal 35 Adhesive 34 Oil Absorber

Claims (5)

  1. 　上端が開口し、下端が閉塞したシリンダ（１１）と、
    　前記シリンダ（１１）に上下に移動可能に挿入されたロッド（１２）と、
    　前記ロッド（１２）を上方に付勢するリターンスプリング（１４）と、
    　前記ロッド（１２）に負荷される下向きの力を前記シリンダ（１１）の内部の作動油で緩衝する油圧ダンパ機構（１５）と、
    　前記ロッド（１２）の移動に伴って摺接するように前記シリンダ（１１）の上端開口の内周に取り付けられた環状のオイルシール（１６）と、を備える油圧式オートテンショナにおいて、
    　前記シリンダ（１１）の内部から前記オイルシール（１６）の摺接部分を通って上方ににじみ出た作動油を吸収するオイル吸収体（３４）を前記オイルシール（１６）の上側に設けたことを特徴とする油圧式オートテンショナ。     A cylinder (11) whose upper end is open and whose lower end is closed;
    A rod (12) inserted into the cylinder (11) so as to be movable up and down;
    A return spring (14) for urging the rod (12) upward;
    A hydraulic damper mechanism (15) for buffering downward force applied to the rod (12) with hydraulic oil inside the cylinder (11);
    In a hydraulic auto tensioner comprising an annular oil seal (16) attached to the inner periphery of the upper end opening of the cylinder (11) so as to come into sliding contact with the movement of the rod (12),
    An oil absorber (34) that absorbs hydraulic oil that oozes upward from the inside of the cylinder (11) through the sliding contact portion of the oil seal (16) is provided above the oil seal (16). Features a hydraulic auto tensioner.
  2. 　前記オイル吸収体（３４）は、環状の前記オイルシール（１６）の上側に配置された環状体である請求項１に記載の油圧式オートテンショナ。 The hydraulic auto tensioner according to claim 1, wherein the oil absorber (34) is an annular body disposed above the annular oil seal (16).
  3. 　前記オイル吸収体（３４）は、多数の繊維で構成されている請求項１または２に記載の油圧式オートテンショナ。 The hydraulic auto tensioner according to claim 1 or 2, wherein the oil absorber (34) is composed of a large number of fibers.
  4. 　前記繊維として、合成樹脂繊維が用いられている請求項３に記載の油圧式オートテンショナ。 The hydraulic auto tensioner according to claim 3, wherein a synthetic resin fiber is used as the fiber.
  5. 　前記オイル吸収体（３４）は、前記オイルシール（１６）の上側に接着剤（３５）で固定されている請求項１から４のいずれかに記載の油圧式オートテンショナ。 The hydraulic auto tensioner according to any one of claims 1 to 4, wherein the oil absorber (34) is fixed to the upper side of the oil seal (16) with an adhesive (35).
PCT/JP2018/009437 2017-03-17 2018-03-12 Hydraulic auto-tensioner WO2018168745A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109185408A (en) * 2018-10-18 2019-01-11 盖茨优霓塔传动***（上海）有限公司 A kind of hydraulic stem and the hydraulic tensioner with the hydraulic stem

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59168051U (en) * 1983-04-26 1984-11-10 株式会社椿本チエイン Tensioner for toothed belts
JPH0182371U (en) * 1987-11-25 1989-06-01
JPH0852832A (en) * 1994-08-12 1996-02-27 Mitsubishi Paper Mills Ltd Oil absorbing material
JP2009222215A (en) * 2008-03-19 2009-10-01 Sugatsune Ind Co Ltd Fluid damper

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59168051U (en) * 1983-04-26 1984-11-10 株式会社椿本チエイン Tensioner for toothed belts
JPH0182371U (en) * 1987-11-25 1989-06-01
JPH0852832A (en) * 1994-08-12 1996-02-27 Mitsubishi Paper Mills Ltd Oil absorbing material
JP2009222215A (en) * 2008-03-19 2009-10-01 Sugatsune Ind Co Ltd Fluid damper

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109185408A (en) * 2018-10-18 2019-01-11 盖茨优霓塔传动***（上海）有限公司 A kind of hydraulic stem and the hydraulic tensioner with the hydraulic stem
CN109185408B (en) * 2018-10-18 2023-09-29 盖茨优霓塔传动***（上海）有限公司 Hydraulic rod and hydraulic tensioner with same

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