JP2008296626A - Bush bearing and rack pinion type hydraulic power steering device for automobile using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bush bearing in which a rack shaft can be supported for a long period with appropriate interference to provide good moving characteristics in an axial direction with low sliding friction resistance with respect to the rack shaft without generating a clearance, and generation of abnormal noise caused by vibration is prevented, and machining man-hours and assembly man-hours are decreased to reduce cost, and to provide a rack pinion type power hydraulic steering device for an automobile using the same. <P>SOLUTION: The rack pinion type power hydraulic steering device 1 for an automobile comprises: an outer cylinder 4 in which the rack shaft 3 is inserted to the inside 2 thereof; the bush bearing 13 fitted to an inner circumferential surface 9 of an outer cylinder; a small-diameter seal ring 15 received by a bush groove 14; a large-diameter seal ring 17 received by an inner cylinder groove 16; and an inside seal ring 23 brought into slide-contact with an outer circumferential surface 18 of the rack shaft 3 in an A direction, and is brought into contact with a large diameter inner circumferential surface 22 of an inner cylinder. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、ブッシュ軸受、特に自動車のラックピニオン式油圧パワーステアリング装置におけるラック軸を移動自在に支持するために用いて好適なブッシュ軸受に関する。   The present invention relates to a bush bearing, and more particularly to a bush bearing suitable for use in movably supporting a rack shaft in a rack and pinion type hydraulic power steering apparatus of an automobile.

実開平１−１７１７７５号公報Japanese Utility Model Publication 1-17-1775 実開平５−４９５６６号公報Japanese Utility Model Publication No. 5-49566 実用新案登録第２５７６１９２号公報Utility Model Registration No. 2576192 特開平１１−１１５７７３号公報JP 11-115773 A 特開２００１−１０５１１号公報JP 2001-10511 A

特許文献１から５に記載されているように、ラックピニオン式ステアリング装置、特にラックピニオン式油圧パワーステアリング装置において、ピニオンの歯に噛み合うラック歯を有したラック軸は、内部に油液を収容した外筒（ハウジング）の一端部でブッシュ軸受を介して移動自在に支持される。ブッシュ軸受としては、外筒の一端部の内周面に嵌着される金属製又は樹脂製の内筒と、この内筒の内周面に装着されると共に内周面でラック軸の外周面に摺動自在に接触する合成樹脂製のブッシュとを具備したものが種々提案されている。   As described in Patent Documents 1 to 5, in a rack and pinion type steering device, in particular, a rack and pinion type hydraulic power steering device, a rack shaft having rack teeth that mesh with the teeth of the pinion houses oil. It is movably supported at one end of the outer cylinder (housing) via a bush bearing. As a bush bearing, an inner cylinder made of metal or resin that is fitted to the inner peripheral surface of one end of the outer cylinder, and an outer peripheral surface of the rack shaft that is mounted on the inner peripheral surface of the inner cylinder and is the inner peripheral surface There have been proposed various types including a synthetic resin bush that is slidably in contact with the bush.

斯かるブッシュ軸受において、ブッシュの内周面とラック軸の外周面との間に隙間があると、自動車の走行時にブッシュとラック軸との衝突音（異音）が生じて乗員に不快感を与える虞があり、隙間が生じないないようにラック軸をブッシュでもって大きな代締めをもってきつく締め付けるようにすると、軸方向の摺動摩擦抵抗が大きくなって、ラック軸を良好な移動特性をもって支持できなくなる一方、支持するラック軸に対して小さな締め代をもって緩く締め付けるようにすると、ラック軸に対して低い摺動摩擦抵抗をもった軸方向の良好な移動特性は期待できるが、ラック軸に大きな心ずれやラック軸との間に隙間等が生じ易くなって、径方向の剛性的支持が低下して衝突音発生の原因ともなる。   In such a bushing bearing, if there is a gap between the inner peripheral surface of the bush and the outer peripheral surface of the rack shaft, a collision sound (abnormal noise) between the bush and the rack shaft is generated when the vehicle is running, and the passengers feel uncomfortable. If the rack shaft is tightly tightened with a bush with a large margin so that there is no gap, the sliding frictional resistance in the axial direction will increase and the rack shaft cannot be supported with good movement characteristics. On the other hand, if the rack shaft to be supported is tightened loosely with a small tightening margin, good movement characteristics in the axial direction with low sliding friction resistance can be expected, but the rack shaft has a large misalignment and A gap or the like is likely to be generated between the rack shaft and the radial support is lowered, which may cause a collision sound.

加えて、ブッシュを内筒の内周面とラック軸の外周面と間に介在させる場合は、内筒を介して合成樹脂製のブッシュを適度の締め代をもってラック軸の外周面に締め付けるのであるが、長期の使用でブッシュにクリープ変形、へたり等が生じると、斯かるブッシュによっては初期の締め代をもってラック軸の外周面に締め付けることが困難となり、ブッシュとラック軸の外周面との間に隙間が生じ易くなって、これまた振動によってラック軸のブッシュへの衝突で異音が生じる虞がある。   In addition, when the bush is interposed between the inner peripheral surface of the inner cylinder and the outer peripheral surface of the rack shaft, the synthetic resin bush is tightened to the outer peripheral surface of the rack shaft with an appropriate tightening margin through the inner cylinder. However, when creep deformation, sag, etc. occur in the bush over a long period of use, it becomes difficult to tighten the outer periphery of the rack shaft with the initial allowance depending on the bush, and there is a problem between the bush and the outer peripheral surface of the rack shaft. There is a possibility that a gap is easily formed in the rack, and abnormal noise may be generated due to the collision of the rack shaft with the bush due to vibration.

一方、ラック軸は、通常、ピニオンに隣接した側とピニオンから離れた側との二つの部位でブッシュ軸受により移動自在に支持されるが、特に、ラックピニオン式油圧パワーステアリング装置においてピニオンから離れた側のラック軸の部位、言い換えると、内部に油液を収容した外筒の開口側の一端部では、ブッシュ軸受によるラック軸の移動自在な支持に加えて外筒の内部から外部への油液の漏出防止がシールリングをもって行われるが、斯かる漏出防止用のシールリングとブッシュ軸受とを個別に外筒の内部へ装着しなければならないようにすると、煩雑な作業となり、これによって価格上昇を招来することになる虞がある。   On the other hand, the rack shaft is normally movably supported by the bush bearings at two portions, the side adjacent to the pinion and the side away from the pinion. In particular, the rack shaft is separated from the pinion in the rack and pinion type hydraulic power steering device. In addition to the movable support of the rack shaft by the bush bearing, the oil liquid from the inside of the outer cylinder to the outside is provided at one end of the opening side of the outer cylinder in which the oil liquid is accommodated. The leakage prevention is performed with a seal ring. However, if such a leakage prevention seal ring and bushing bearing must be individually installed inside the outer cylinder, it becomes a complicated operation, which increases the price. There is a risk of being invited.

本発明は、前記諸点に鑑みてなされたものであって、その目的とするところは、隙間を生じさせることなしにラック軸に対して低い摺動摩擦抵抗をもって軸方向の良好な移動特性を得ることができるように適度な締め代をもってラック軸を長期に亘って支持することができて、振動による異音発生をなくし得、しかも、加工工数及び組立工数を低減できて価格低下を図り得るブッシュ軸受及びそれを用いた自動車のラックピニオン式油圧パワーステアリング装置を提供することにある。   The present invention has been made in view of the above-described points, and an object of the present invention is to obtain a good axial movement characteristic with a low sliding frictional resistance with respect to the rack shaft without causing a gap. Bush bearings that can support the rack shaft over a long period of time with an appropriate tightening allowance, eliminate the generation of abnormal noise due to vibration, and reduce the number of processing and assembly steps, thereby reducing the price. Another object of the present invention is to provide an automotive rack and pinion type hydraulic power steering apparatus using the same.

本発明のブッシュ軸受は、内部にラック軸が挿通される外筒の一端部の外筒小径内周面に嵌装されると共に外筒の内部に挿通されたラック軸の一端部が貫通される縮径自在な合成樹脂製のブッシュと、外筒の内部に挿通されたラック軸の一端部が貫通されると共にブッシュの軸方向の一端に連接されて外筒の一端部の外筒大径内周面に嵌装される内筒と、ブッシュ及び内筒を互いに連結する連結手段とを具備しており、ブッシュは、軸方向のブッシュ一端面から軸方向のブッシュ他端面まで伸びたスリットと、ラック軸の外周面に摺動自在に接触する円筒状のブッシュ内周面と、外筒小径内周面に対面する円筒状のブッシュ小径外周面と、外筒小径内周面に弾性的に押圧接触する外側の小径シールリングを受容するようにブッシュ小径外周面に形成されている環状のブッシュ溝と、ブッシュ小径外周面に環状のブッシュ傾斜外周面を介して軸方向において連接されていると共に外筒大径内周面に対面する円筒状のブッシュ大径外周面と、ブッシュ他端面からブッシュ一端面に向かって夫々軸方向に伸びていると共に軸心周りの方向において配列された複数個のブッシュ凹所とを具備しており、内筒は、ブッシュ他端面に接触する軸方向の内筒一端面と、外筒大径内周面に嵌着される内筒外周面と、外筒大径内周面に弾性的に押圧接触する外側の大径シールリングを受容するように内筒外周面に形成された環状の内筒溝と、ラック軸の外周面に摺動自在に接触する円筒状の内筒内周面と、内筒一端面及び内筒内周面の間に配されていると共に内筒内周面よりも大径であって、ラック軸の外周面に内周面で摺動自在に接触する内側シールリングの外周面が接触する内筒大径内周面とを具備している。   The bush bearing of the present invention is fitted to the inner peripheral surface of the outer cylinder with a small diameter at one end of the outer cylinder through which the rack shaft is inserted, and is also penetrated through one end of the rack shaft inserted into the outer cylinder. A bush made of synthetic resin that can be reduced in diameter, and one end of a rack shaft inserted through the inside of the outer cylinder are penetrated and connected to one end of the bush in the axial direction, and the inner diameter of the outer cylinder at one end of the outer cylinder is increased. An inner cylinder fitted to the peripheral surface, and a connecting means for connecting the bush and the inner cylinder to each other, the bush extending from one end surface of the axial bush to the other end surface of the axial bush; A cylindrical bush inner peripheral surface that is slidably in contact with the outer peripheral surface of the rack shaft, a cylindrical bush small outer peripheral surface facing the outer peripheral small diameter inner peripheral surface, and an outer cylindrical small inner peripheral surface that is elastically pressed Bush small diameter outer surface to accept the outer small diameter seal ring in contact An annular bush groove formed and a cylindrical bush large-diameter outer surface connected to the bush small-diameter outer peripheral surface in the axial direction via an annular bushing inclined outer peripheral surface and facing the outer cylindrical large-diameter inner peripheral surface A plurality of bush recesses extending in the axial direction from the other end surface of the bush toward the one end surface of the bush and arranged in a direction around the axis, and the inner cylinder is disposed on the other end surface of the bush. An axial end of the inner cylinder that comes into contact, an outer peripheral surface of the inner cylinder that is fitted to the inner peripheral surface of the outer diameter of the outer cylinder, and an outer large-diameter seal ring that elastically presses and contacts the inner peripheral surface of the outer cylinder. An annular inner cylindrical groove formed on the outer peripheral surface of the inner cylinder to receive, a cylindrical inner cylinder inner peripheral surface that slidably contacts the outer peripheral surface of the rack shaft, one end surface of the inner cylinder, and an inner cylinder inner periphery The rack shaft is arranged between the surfaces and has a larger diameter than the inner peripheral surface of the inner cylinder. The outer peripheral surface of the inner seal ring slidably contacts the inner circumferential surface on the outer peripheral surface is provided with an inner cylindrical large diameter inner peripheral surface in contact.

本発明のブッシュ軸受によれば、ブッシュと内筒とが軸方向に連接されて外筒の一端部の外筒小径内周面及び外筒大径内周面を有した外筒内周面に嵌装されている上に、ブッシュがスリット及び複数個のブッシュ凹所を具備するために、ブッシュのクリープ変形、へたり等を好ましく回避できて、初期の締め代をもって長期に亘ってラック軸の外周面をブッシュによって締め付けることができ、而して、隙間を生じさせることなしにラック軸に対して低い摺動摩擦抵抗をもって軸方向の良好な移動特性を得ることができるようにラック軸を長期に亘って支持することができて、振動による異音発生をなくし得、しかも、内筒が、内筒一端面及び円筒内周面の間に配されている内筒大径内周面を具備しているために、斯かる内筒大径内周面に予め内側シールリングを装着できるために、加工工数及び組立工数を低減できて価格低下を図り得る。   According to the bush bearing of the present invention, the bush and the inner cylinder are connected in the axial direction, and the outer cylinder inner peripheral surface having the outer cylinder small-diameter inner peripheral surface and the outer cylinder large-diameter inner peripheral surface at one end portion of the outer cylinder is provided. In addition, since the bush has a slit and a plurality of bush recesses, creep deformation of the bush, sag, etc. can be preferably avoided, and the rack shaft can be extended for a long time with an initial tightening allowance. The outer peripheral surface can be tightened by a bush, and thus the rack shaft can be extended for a long time so that good movement characteristics in the axial direction can be obtained with low sliding friction resistance against the rack shaft without generating a gap. The inner cylinder has an inner cylinder large-diameter inner circumferential surface arranged between one end surface of the inner cylinder and the inner circumferential surface of the cylinder. For this reason, the inner diameter of the inner cylinder In order to be able to mount the inner sealing ring, may work to lower prices and reduces the number of processing steps and assembling steps.

内筒は、アルミ、鉄等の金属材料でも、またこれらに代えて所定の剛性をもった合成樹脂材料で形成してもよく、ブッシュの形成材料としての合成樹脂は、耐摩耗性に優れて低摩擦特性を有し、しかも、所定の撓み性と剛性とを有すると共に熱伸縮の少ないものが好ましく、具体的には、ポリアセタール樹脂、ポリアミド樹脂、ポリオレフィン樹脂及びフッ素樹脂のうちの少なくとも一つを含む合成樹脂等を挙げることができる。   The inner cylinder may be formed of a metal material such as aluminum or iron, or alternatively may be formed of a synthetic resin material having a predetermined rigidity, and the synthetic resin as a material for forming the bush has excellent wear resistance. A material having low friction characteristics and having a predetermined flexibility and rigidity and low thermal expansion and contraction is preferable. Specifically, at least one of a polyacetal resin, a polyamide resin, a polyolefin resin, and a fluorine resin is used. Examples thereof include synthetic resins.

好ましい例では、内筒は、内筒一端面において開口する一端から軸方向に伸びていると共に軸心周りの方向において角度間隔をもって配列された複数の内筒凹所を有しており、また他の好ましい例では、内筒は、内筒内周面の径よりも大径の円筒状の他の内筒大径内周面と、この他の内筒大径内周面の軸方向の一端に外周縁で連接された環状の内筒中間端面と、内筒中間端面において開口する一端から軸方向に夫々伸びていると共に軸心周りの方向に等角度間隔をもって配列されている複数の他の内筒凹所を有しており、内筒がこれら内筒凹所を有していると、ブッシュ軸受を外筒の一端部の外筒内周面に嵌着する場合に、外筒内周面の寸法精度が多少悪くても、内筒凹所によってこれを吸収できるために、内筒内周面により偏って過度にラック軸の外周面が押し付けられたり、内筒内周面とラック軸の外周面との間に必要以上の隙間（軸受隙間）が生じたりすることを防止できる。   In a preferred example, the inner cylinder has a plurality of inner cylinder recesses extending in the axial direction from one end opened at one end surface of the inner cylinder and arranged at angular intervals in the direction around the axis. In a preferred example of the above, the inner cylinder has another cylindrical inner diameter larger inner circumferential surface having a larger diameter than the inner circumferential surface of the inner cylinder, and one axial end of the other inner cylinder larger inner diameter surface. And a plurality of other inner cylinder intermediate end faces that are connected to each other at the outer peripheral edge, and extending in the axial direction from one end opened at the inner cylinder intermediate end face and arranged at equiangular intervals in the direction around the axis. If the inner cylinder has these inner cylinder recesses, when the bush bearing is fitted to the inner cylinder inner peripheral surface of one end of the outer cylinder, the inner cylinder inner circumference Even if the dimensional accuracy of the surface is somewhat poor, this can be absorbed by the inner cylinder recess, and therefore the bias is excessively biased by the inner peripheral surface of the inner cylinder. Or the outer peripheral surface of the click-axis is pressed, that the required minimum clearance between the inner cylinder peripheral surface and the rack shaft outer peripheral surface of the (bearing clearance) is or cause can be prevented.

スリットは、軸方向と平行に伸びていても、これに代えて、軸方向に対して傾斜して伸びていてもよく、更には、軸方向と平行に伸びたものと、軸方向に対して傾斜して伸びたものとが混在していてもよい。   The slit may extend in parallel to the axial direction, or alternatively, may be inclined and extended with respect to the axial direction. It may be mixed with slanted and elongated ones.

本発明による自動車のラックピニオン式油圧パワーステアリング装置は、油液が充填された内部にラック軸が挿通される外筒と、外筒の内部に挿通されたラック軸の一端部を摺動自在に支持するべく、外筒小径内周面及び外筒大径内周面に嵌装された上記のいずれかの態様のブッシュ軸受と、ブッシュ溝に受容された小径シールリングと、内筒溝に受容された大径シールリングと、ラック軸の外周面に内周面で摺動自在に接触すると共に外周面が内筒大径内周面に接触する内側シールリングとを有している。   A rack and pinion type hydraulic power steering device for an automobile according to the present invention is slidable between an outer cylinder through which a rack shaft is inserted into an oil-filled interior and one end portion of the rack shaft inserted into the outer cylinder. In order to support, the bushing bearing of any one of the above-described aspects is fitted to the outer peripheral small diameter inner peripheral surface and the outer peripheral large diameter inner peripheral surface, the small diameter seal ring received in the bush groove, and received in the inner cylindrical groove A large-diameter seal ring, and an inner seal ring that is slidably in contact with the outer peripheral surface of the rack shaft on the inner peripheral surface and whose outer peripheral surface is in contact with the inner peripheral surface of the inner cylinder.

小径シールリング及び大径シールリングは、一般に使用されているＯリングを好ましく用いることができ、内側シールリングは、断面において円形、楕円形、矩形又は扁平状の長円形を有していても、これに代えて、断面Ｘ字形状、断面Ｕ字形状又は断面台形状等の他の形状であってもよく、また、好ましくは、天然ゴム製又は合成ゴム製であるが、その他の弾性を有する熱可塑性合成樹脂製、例えばポリエステルエラストマー製であってもよい。   As the small-diameter seal ring and the large-diameter seal ring, a generally used O-ring can be preferably used, and the inner seal ring may have an oval shape that is circular, elliptical, rectangular or flat in cross section. Alternatively, other shapes such as an X-shaped cross-section, a U-shaped cross-section or a trapezoidal cross-section may be used. Preferably, the shape is made of natural rubber or synthetic rubber, but has other elasticity. It may be made of a thermoplastic synthetic resin, for example, a polyester elastomer.

本発明によれば、隙間を生じさせることなしにラック軸に対して低い摺動摩擦抵抗をもって軸方向の良好な移動特性を得ることができるように適度な締め代をもってラック軸を長期に亘って支持することができて、振動による異音発生をなくし得、しかも、加工工数及び組立工数を低減できて価格低下を図り得るブッシュ軸受及びそれを用いた自動車のラックピニオン式油圧パワーステアリング装置を提供することができる。   According to the present invention, the rack shaft is supported over a long period of time with a moderate tightening margin so that a good moving characteristic in the axial direction can be obtained with a low sliding friction resistance with respect to the rack shaft without generating a gap. Provided is a bush bearing that can eliminate abnormal noise due to vibration and that can reduce the processing man-hours and assembly man-hours and can reduce the price, and a rack and pinion type hydraulic power steering device for an automobile using the same. be able to.

次に本発明を、図に示す好ましい実施の形態の例を参照して更に詳細に説明する。なお、本発明はこれらの例に何等限定されないのである。   The invention will now be described in more detail with reference to the preferred embodiment examples shown in the drawings. The present invention is not limited to these examples.

図１から図９において、本例の自動車のラックピニオン式油圧パワーステアリング装置１は、油液が充填された内部２にラック軸３が挿通される外筒（ハウジング）４と、外筒４の内部２に挿通されたラック軸３の一端部５を軸方向であるＡ方向に摺動自在に支持するべく、外筒４の一端部６の円筒状の外筒小径内周面７及び外筒大径内周面８を有した外筒内周面９に嵌装されていると共にブッシュ１１及び内筒１２を有したブッシュ軸受１３と、ブッシュ１１の円環状のブッシュ溝１４に受容された小径シールリング１５と、内筒１２の円環状の内筒溝１６に受容された大径シールリング１７と、ラック軸３の円筒状の外周面１８に円筒状の内周面１９でＡ方向に摺動自在に接触すると共に円筒状の外周面２１が内筒１２の円筒状の内筒大径内周面２２に接触する内側シールリング２３と、内筒１２の円筒状の内筒大径外周面２４に締付リング２５により一端部２６が固着された泥水及び塵埃侵入防止用の蛇腹状の伸縮カバー２７とを有している。   1 to 9, a rack and pinion type hydraulic power steering device 1 for an automobile according to the present embodiment includes an outer cylinder (housing) 4 through which a rack shaft 3 is inserted into an interior 2 filled with oil, and an outer cylinder 4 In order to slidably support one end portion 5 of the rack shaft 3 inserted through the inside 2 in the A direction which is the axial direction, the cylindrical outer tube small-diameter inner peripheral surface 7 and the outer tube of the one end portion 6 of the outer tube 4 A small-diameter received in a bush bearing 13 having a bush 11 and an inner cylinder 12 and an annular bush groove 14 of the bush 11 while being fitted to an outer cylinder inner peripheral surface 9 having a large-diameter inner peripheral surface 8. The seal ring 15, the large-diameter seal ring 17 received in the annular inner cylindrical groove 16 of the inner cylinder 12, and the cylindrical inner peripheral surface 19 are slid in the A direction on the cylindrical outer peripheral surface 18 of the rack shaft 3. The cylindrical outer cylinder 21 of the inner cylinder 12 is in contact with the movable body and the cylindrical outer peripheral surface 21 is large An inner seal ring 23 that contacts the inner peripheral surface 22 and a bellows-like shape for preventing intrusion of muddy water and dust, in which one end portion 26 is fixed to the cylindrical inner cylinder outer peripheral surface 24 of the inner cylinder 12 by a tightening ring 25. An elastic cover 27 is provided.

ラック軸３の他端部側でのステアリングホイール（操舵輪）の回転で回転されるピニオンとの噛合い機構、外筒４の内部２への油液の供給機構、ラック軸３の一端部５側でのラック軸３のＡ方向の移動を車軸へ伝達するタイロッド等との連結機構は、公知であるので詳細な説明を省く。   A meshing mechanism with a pinion rotated by rotation of a steering wheel (steering wheel) on the other end side of the rack shaft 3, a mechanism for supplying oil to the inside 2 of the outer cylinder 4, and one end portion 5 of the rack shaft 3 Since a connecting mechanism with a tie rod or the like for transmitting the movement of the rack shaft 3 in the A direction on the side to the axle is well known, detailed description thereof will be omitted.

外筒４の一端部６は、円筒状の外筒外周面３１と、内部２を規定する外筒小径内周面７と、円環状の嵌合凹所３２が形成されていると共に外筒小径内周面７の径よりも大径の外筒大径内周面８と、Ａ方向の一端では外筒小径内周面７に、Ａ方向の他端では外筒大径内周面８に夫々連接した截頭円錐状の外筒傾斜内周面３３と、径方向の外周端では外筒外周面３１に、径方向の内周端では外筒大径内周面８に夫々直交して連接した円環状の外筒端面３４とを具備している。   One end portion 6 of the outer cylinder 4 is formed with a cylindrical outer cylinder outer peripheral surface 31, an outer cylinder small-diameter inner peripheral surface 7 defining the inside 2, and an annular fitting recess 32 and an outer cylinder small-diameter An outer cylinder large-diameter inner peripheral surface 8 larger in diameter than the inner peripheral surface 7, an outer cylinder small-diameter inner peripheral surface 7 at one end in the A direction, and an outer cylinder large-diameter inner peripheral surface 8 at the other end in the A direction. The outer cone inclined inner peripheral surface 33 having a truncated conical shape connected to each other, and the outer cylinder outer peripheral surface 31 at the outer peripheral end in the radial direction and the outer cylinder large diameter inner peripheral surface 8 at the inner peripheral end in the radial direction are orthogonal to each other. And an annular outer cylinder end surface 34 connected to each other.

ブッシュ軸受１３は、内部２にラック軸３が挿通される外筒４の一端部６の外筒小径内周面７に嵌装されると共に外筒４の内部２に挿通されたラック軸３の一端部５が貫通される縮径自在な合成樹脂製のブッシュ１１と、外筒４の内部２に挿通されたラック軸３の一端部５が貫通されると共にブッシュ１１のＡ方向の一端に連接されて外筒４の一端部６の外筒大径内周面８に嵌装される内筒１２と、ブッシュ１１及び内筒１２を互いに連結する連結手段３５とを具備している。   The bush bearing 13 is fitted to the inner peripheral surface 7 of the outer cylinder with a small diameter at one end 6 of the outer cylinder 4 through which the rack shaft 3 is inserted, and the bush shaft 13 is inserted into the inner 2 of the outer cylinder 4. A bush 11 made of a synthetic resin that can be freely reduced in diameter through which the one end 5 passes, and one end 5 of the rack shaft 3 inserted through the inside 2 of the outer cylinder 4 are penetrated and connected to one end of the bush 11 in the A direction. The inner cylinder 12 fitted to the outer cylinder large-diameter inner peripheral surface 8 of the one end portion 6 of the outer cylinder 4 and the connecting means 35 for connecting the bush 11 and the inner cylinder 12 to each other are provided.

内側円筒状部３６と、外側円筒状部３７と、内側円筒状部３６及び外側円筒状部３７をＡ方向の一端部で互いに連結した円環状部３８とを一体的に有したブッシュ１１は、Ａ方向の円環状のブッシュ一端面４１からＡ方向の円環状のブッシュ他端面４２にまで伸びたスリット４３と、ラック軸３の外周面１８にＡ方向に摺動自在に締め代をもって接触する内側円筒状部３６の円筒状のブッシュ内周面４４と、外筒４の外筒小径内周面７に対面する外側円筒状部３７の円筒状のブッシュ小径外周面４５と、外筒小径内周面７に外周面で弾性的に押圧接触する外側の小径シールリング１５を受容するようにブッシュ小径外周面４５に形成されている円環状のブッシュ溝１４と、ブッシュ小径外周面４５に円環状であって截頭円錐面状のブッシュ傾斜外周面４６を介してＡ方向において連接されていると共に外筒大径内周面８に対面する円筒状のブッシュ大径外周面４７と、ブッシュ他端面４２からブッシュ一端面４１に向かって夫々Ａ方向に伸びていると共に軸心周りの方向であるＲ方向において配列された複数個の有底のブッシュ凹所４８とを具備している。   The bush 11 integrally having an inner cylindrical portion 36, an outer cylindrical portion 37, and an annular portion 38 in which the inner cylindrical portion 36 and the outer cylindrical portion 37 are connected to each other at one end in the A direction, A slit 43 extending from one end face 41 of the annular bushing in the A direction to the other end face 42 of the annular bushing in the A direction, and an inner side contacting the outer peripheral surface 18 of the rack shaft 3 slidably in the A direction with a tightening margin. The cylindrical bush inner peripheral surface 44 of the cylindrical portion 36, the cylindrical bush small diameter outer peripheral surface 45 of the outer cylindrical portion 37 facing the outer cylindrical small diameter inner peripheral surface 7 of the outer cylinder 4, and the outer cylinder small diameter inner periphery An annular bush groove 14 formed in the bush small-diameter outer peripheral surface 45 so as to receive the outer small-diameter seal ring 15 that elastically presses and contacts the surface 7 on the outer peripheral surface, and an annular shape on the bush small-diameter outer peripheral surface 45. There is a truncated cone-shaped bush tilt A cylindrical bush large-diameter outer peripheral surface 47 that is connected in the A direction via the outer peripheral surface 46 and faces the outer cylindrical large-diameter inner peripheral surface 8, and the bush other end surface 42 toward the bush one end surface 41 respectively. A plurality of bottomed bush recesses 48 extending in the direction and arranged in the R direction, which is a direction around the axis.

スリット４３は、ブッシュ一端面４１で開口すると共にブッシュ一端面４１からＡ方向に平行に伸びた平行スリット５１と、ブッシュ他端面４２で開口すると共にブッシュ他端面４２からＡ方向に平行に伸びた平行スリット５２と、一方では平行スリット５１に、他方では平行スリット５２に連通されてＡ方向に対して傾斜して伸びた傾斜スリット５３とを有しており、ブッシュ１１は、斯かるスリット４３により径方向の縮径が容易になされるようになっている。   The slit 43 opens at one end surface 41 of the bush and extends parallel to the A direction from the one end surface 41 of the bush, and parallel extends from the other end surface 42 of the bush and parallel to the A direction from the other end surface 42 of the bush. The slit 52 has, on the one hand, a parallel slit 51 and, on the other hand, an inclined slit 53 which is communicated with the parallel slit 52 and extends with an inclination with respect to the A direction. The direction of the diameter is easily reduced.

ブッシュ内周面４４は、ラック軸３の一端部５が貫通する貫通孔５４を規定しており、ブッシュ傾斜外周面４６は、外筒傾斜内周面３３に接触しており、斯かる接触によりブッシュ１１の外筒４の一端部６への更なる挿入が阻止されている。   The bush inner peripheral surface 44 defines a through hole 54 through which one end portion 5 of the rack shaft 3 passes, and the bush inclined outer peripheral surface 46 is in contact with the outer cylinder inclined inner peripheral surface 33, Further insertion of the bush 11 into the one end 6 of the outer cylinder 4 is prevented.

内側円筒部５６と、外側円筒部５７と、内側円筒部５６及び外側円筒部５７をＡ方向の中間部で互いに連結する円環状部５８とを一体的に有する内筒１２は、外筒４の一端部６の外部に位置した円筒状の内筒大径外周面２４と、ブッシュ他端面４２に接触するＡ方向の円環状の内筒一端面６１と、外筒大径内周面８に嵌着される円筒状の内筒外周面６２と、外筒大径内周面８に外周面で弾性的に押圧接触する外側の大径シールリング１７を受容するように内筒外周面６２に形成された円環状の内筒溝１６と、ラック軸３の外周面１８に軸受隙間をもってＡ方向に摺動自在に接触する円筒状の内筒内周面６３と、Ａ方向において内筒一端面６１及び内筒内周面６３の間に配されていると共に内筒内周面６３の径よりも大径であって、ラック軸３の外周面１８に内周面１９でＡ方向に摺動自在に接触する内側シールリング２３の外周面２１が接触する内筒大径内周面６４と、内筒大径内周面６４及び内筒内周面６３の径よりも大径の円筒状の他の内筒大径内周面６５と、内筒大径内周面６５のＡ方向の一端に外周縁で直交して連接された円環状の内筒中間端面６６と、内筒内周面６３の径よりも大径であって、内筒大径内周面６４の径よりも小径であると共にＡ方向の一端で内筒中間端面６６の内周縁に直交して連接された内筒中間内周面６７と、内筒一端面６１において開口する一端からＡ方向に夫々伸びていると共にＲ方向において等角度間隔をもって配列された有底の複数の内筒凹所６８と、内筒中間端面６６において開口する一端からＡ方向に夫々伸びていると共にＲ方向に等角度間隔をもって配列されている有底の複数の内筒凹所６９と、内筒大径内周面６５のＡ方向の他端に内周縁で直交して連接された円環状の内筒他端面７１と、内周縁で内筒外周面６２に、外周縁で内筒大径外周面２４に夫々直交して連接されていると共に外筒端面３４に接触した円環状の内筒外側段部端面７２と、内周縁で内筒内周面６３に、外周縁で内筒大径内周面６４に夫々直交して連接されている内筒内側段部端面７３とを有している。   The inner cylinder 12 integrally including an inner cylindrical portion 56, an outer cylindrical portion 57, and an annular portion 58 that connects the inner cylindrical portion 56 and the outer cylindrical portion 57 at an intermediate portion in the A direction is the A cylindrical inner cylinder large-diameter outer peripheral surface 24 located outside the one end 6, an A-shaped annular inner cylinder one end surface 61 contacting the bushing other end surface 42, and an outer cylinder large-diameter inner peripheral surface 8. Formed on the outer peripheral surface 62 of the inner cylinder so as to receive the outer peripheral surface 62 of the cylindrical inner cylinder to be worn and the outer large-diameter seal ring 17 that elastically presses and contacts the outer peripheral large-diameter inner peripheral surface 8 with the outer peripheral surface. An annular inner cylindrical groove 16 formed in the cylindrical shaft, a cylindrical inner cylinder inner peripheral surface 63 that is slidably in contact with the outer peripheral surface 18 of the rack shaft 3 in the A direction with a bearing gap, and an inner cylinder one end surface 61 in the A direction. And the inner diameter of the inner cylinder 63 is larger than the diameter of the inner circumference 63 of the inner cylinder, and the rack shaft 3 An inner cylinder large-diameter inner peripheral surface 64 in contact with the outer peripheral surface 21 of the inner seal ring 23 that is slidably in contact with the outer peripheral surface 18 in the A direction on the inner peripheral surface 19, and an inner cylinder large-diameter inner peripheral surface 64 and an inner cylinder The other cylindrical inner diameter inner circumferential surface 65 having a larger diameter than the inner circumferential surface 63 and a circle connected to one end in the A direction of the inner cylindrical larger diameter inner circumferential surface 65 at an outer peripheral edge. The inner cylinder intermediate end face 66 is larger than the diameter of the annular inner cylinder intermediate end face 66 and the inner cylinder inner peripheral face 63 and smaller than the diameter of the inner cylinder larger inner peripheral face 64 and at one end in the A direction. An inner cylinder intermediate inner peripheral surface 67 connected perpendicularly to the inner peripheral edge of 66, and a bottomed structure extending in the A direction from one end opened at the inner cylinder one end surface 61 and arranged at equal angular intervals in the R direction. A plurality of inner cylinder recesses 68 and one end opened at the inner cylinder intermediate end surface 66 extend in the A direction and in the R direction, etc. A plurality of bottomed inner cylinder recesses 69 arranged at intervals, and the other end surface of the annular inner cylinder connected perpendicularly at the inner periphery to the other end in the A direction of the inner diameter inner surface 65 of the inner cylinder 71, an annular inner cylinder outer stepped end surface 72 which is connected to the inner cylinder outer peripheral surface 62 at the inner peripheral edge and orthogonally connected to the inner cylindrical outer peripheral surface 24 at the outer peripheral edge and in contact with the outer cylinder end surface 34. And an inner cylinder inner stepped end surface 73 connected to the inner cylinder inner peripheral surface 63 at the inner peripheral edge and orthogonally connected to the inner cylinder large diameter inner peripheral surface 64 at the outer peripheral edge.

内筒内周面６３、内筒大径内周面６４、内筒大径内周面６５及び内筒中間内周面６７は、ラック軸３の一端部５が貫通する貫通孔７４を規定している。   The inner cylinder inner peripheral surface 63, the inner cylinder large diameter inner peripheral surface 64, the inner cylinder large diameter inner peripheral surface 65, and the inner cylinder intermediate inner peripheral surface 67 define a through hole 74 through which one end portion 5 of the rack shaft 3 passes. ing.

内筒外周面６２には、嵌合凹所３２に嵌合されると共に内筒外周面６２から径方向に一体的に突出した円筒状の嵌合突起部７５が形成されており、斯かる嵌合突起部７５の嵌合凹所３２への嵌合でもって、円筒状の内筒外周面６２は、外筒４の外筒大径内周面８に嵌着されており、而して、内筒１２は、嵌合突起部７５の嵌合凹所３２への嵌合により、外筒４の一端部６に対してＡ方向に関して位置決めされている。   The inner cylinder outer peripheral surface 62 is formed with a cylindrical fitting protrusion 75 that is fitted in the fitting recess 32 and protrudes integrally from the inner cylinder outer peripheral surface 62 in the radial direction. By fitting the mating protrusion 75 into the fitting recess 32, the cylindrical inner cylinder outer peripheral surface 62 is fitted to the outer cylinder large diameter inner peripheral surface 8 of the outer cylinder 4, and thus, The inner cylinder 12 is positioned in the A direction with respect to the one end 6 of the outer cylinder 4 by fitting the fitting protrusion 75 into the fitting recess 32.

内筒１２の内筒大径外周面２４には、円環状の溝７７と、Ａ方向において溝７７に連接されていると共に溝７７よりも深い円環状の溝７８とが形成されている。   An annular groove 77 and an annular groove 78 connected to the groove 77 in the A direction and deeper than the groove 77 are formed in the inner cylinder large-diameter outer peripheral surface 24 of the inner cylinder 12.

伸縮カバー２７は、一端部２６が溝７７及び７８に嵌合されて当該一端部２６で内筒１２の内筒大径外周面２４に締付リング２５により固着されている。   One end portion 26 of the extendable cover 27 is fitted in the grooves 77 and 78, and the one end portion 26 is fixed to the inner cylinder large-diameter outer peripheral surface 24 of the inner cylinder 12 by a fastening ring 25.

連結手段３５は、ブッシュ他端面４２においてブッシュ１１に軸対称に一体的に形成されていると共にブッシュ他端面４２からＡ方向に突出した一対の鈎部材８１と、鈎部材８１の先端鈎部８２が嵌入される共に内筒１２の内筒外周面６２に形成された円環状の溝８３と、鈎部材８１の本体部８４が嵌入されていると共に内筒外周面６２に軸対称に形成された切り欠き８５とを具備している。   The connecting means 35 is formed integrally with the bush 11 at the bush other end surface 42 in an axially symmetrical manner and has a pair of flange members 81 projecting from the bush other end surface 42 in the A direction, and a tip flange 82 of the flange member 81. An annular groove 83 formed on the outer peripheral surface 62 of the inner cylinder 12 of the inner cylinder 12 and a main body 84 of the flange member 81 are inserted, and a cut formed symmetrically on the outer peripheral surface 62 of the inner cylinder. And a notch 85.

ブッシュ１１及び内筒１２は、先端鈎部８２の溝８３でのブッシュ１１への係合と、本体部８４の切り欠き８５でのブッシュ１１への係合とにより互いに連結されていると共にＲ方向に相対的に回転しないようになっている。   The bush 11 and the inner cylinder 12 are connected to each other by engagement with the bush 11 in the groove 83 of the distal end flange portion 82 and engagement with the bush 11 in the notch 85 of the main body portion 84 and in the R direction. It is designed not to rotate relative to.

内周面１９でラック軸３の外周面１８にＡ方向に摺動自在に接触する一方、外周面２１で内筒大径内周面６４に接触する内側シールリング２３は、Ａ方向の一方の環状端面９１でブッシュ他端面４２に、Ａ方向の他方の環状端面９２で内筒内側段部端面７３に夫々接触して、これらブッシュ他端面４２及び内筒内側段部端面７３で挟圧されている。   While the inner peripheral surface 19 contacts the outer peripheral surface 18 of the rack shaft 3 slidably in the A direction, the inner seal ring 23 that contacts the inner cylinder large diameter inner peripheral surface 64 at the outer peripheral surface 21 has one side in the A direction. The annular end surface 91 is in contact with the bush other end surface 42 and the other annular end surface 92 in the A direction is in contact with the inner cylinder inner stepped end surface 73, and is pressed between the bush other end surface 42 and the inner cylinder inner stepped end surface 73. Yes.

以上のブッシュ軸受１３を具備したラックピニオン式油圧パワーステアリング装置１では、ブッシュ１１と内筒１２とがＡ方向に連接されて外筒４の一端部６の外筒内周面９に嵌装されている上に、ブッシュ１１がスリット４３及び複数個のブッシュ凹所４８を具備するために、ブッシュ１１のクリープ変形、へたり等を好ましく回避できて、初期の締め代をもって長期に亘ってラック軸３の外周面１８をブッシュ１１によって締め付けることができ、而して、隙間を生じさせることなしにラック軸３に対して低い摺動摩擦抵抗をもってＡ方向の良好な移動特性を得ることができるようにラック軸３を長期に亘って支持することができて、振動による異音発生をなくし得、しかも、内筒１２が、Ａ方向において内筒一端面６１及び円筒状の内筒内周面６３の間に配されている内筒大径内周面６４を具備しているために、斯かる内筒大径内周面６４に予め内側シールリング２３を装着できるために、加工工数及び組立工数を低減できて価格低下を図り得る。   In the rack and pinion type hydraulic power steering apparatus 1 having the bush bearing 13 described above, the bush 11 and the inner cylinder 12 are connected in the A direction and fitted to the inner cylinder inner peripheral surface 9 of the one end portion 6 of the outer cylinder 4. In addition, since the bush 11 includes the slit 43 and the plurality of bush recesses 48, it is possible to preferably avoid creep deformation, sag, etc. of the bush 11, and to extend the rack shaft over a long period with an initial tightening allowance. 3 can be fastened by the bush 11, so that a good moving characteristic in the A direction can be obtained with a low sliding friction resistance with respect to the rack shaft 3 without generating a gap. The rack shaft 3 can be supported over a long period of time, and noise generation due to vibration can be eliminated. In addition, the inner cylinder 12 has an inner cylinder end surface 61 and a cylindrical inner end in the A direction. Since the inner cylinder large-diameter inner peripheral surface 64 arranged between the inner peripheral surfaces 63 is provided, the inner seal ring 23 can be attached to the inner cylinder large-diameter inner peripheral surface 64 in advance. The number of man-hours and assembly man-hours can be reduced and the price can be reduced.

本発明の好ましい実施の形態の一例の断面説明図である。It is sectional explanatory drawing of an example of preferable embodiment of this invention. 図１に示す例のブッシュ及びシールリングの拡大断面説明図である。It is an expanded sectional explanatory view of the bush and seal ring of the example shown in FIG. 図２に示すブッシュの左側面図である。FIG. 3 is a left side view of the bush shown in FIG. 2. 図２に示すブッシュの右側面図である。It is a right view of the bush shown in FIG. 図２に示すブッシュの正面図である。It is a front view of the bush shown in FIG. 図１に示す例の内筒及びシールリングの拡大断面説明図である。It is an expanded sectional explanatory view of the inner cylinder and seal ring of the example shown in FIG. 図６に示す内筒の左側面図である。It is a left view of the inner cylinder shown in FIG. 図６に示す内筒の右側面図である。It is a right view of the inner cylinder shown in FIG. 図６に示す内筒の正面図である。It is a front view of the inner cylinder shown in FIG.

符号の説明Explanation of symbols

１ ラックピニオン式油圧パワーステアリング装置
２ 内部
３ ラック軸
４ 外筒
５、６ 一端部
７ 外筒小径内周面
８ 外筒大径内周面
９ 外筒内周面
１１ ブッシュ
１２ 内筒
１３ ブッシュ軸受
１４ ブッシュ溝
１５ 小径シールリング
１６ 内筒溝
１７ 大径シールリング
１８ 外周面
１９ 内周面
２１ 外周面
２２ 内筒大径内周面
２３ 内側シールリング
３５ 連結手段
４１ ブッシュ一端面
４２ ブッシュ他端面
４３ スリット
４４ ブッシュ内周面
４５ ブッシュ小径外周面
４６ ブッシュ傾斜外周面
４７ ブッシュ大径外周面
４８ ブッシュ凹所
６１ 内筒一端面
６２ 内筒外周面
６３ 内筒内周面
６４ 内筒大径内周面
６５ 内筒大径内周面
６６ 内筒中間端面
６７ 内筒中間内周面
６８、６９ 内筒凹所
７１ 内筒他端面
７２ 内筒外側段部端面
７３ 内筒内側段部端面 DESCRIPTION OF SYMBOLS 1 Rack and pinion type hydraulic power steering device 2 Inside 3 Rack shaft 4 Outer cylinder 5, 6 One end part 7 Outer cylinder small diameter inner peripheral surface 8 Outer cylinder large diameter inner peripheral surface 9 Outer cylinder inner peripheral surface 11 Bush 12 Inner cylinder 13 Bush bearing 14 Bush groove 15 Small diameter seal ring 16 Inner cylinder groove 17 Large diameter seal ring 18 Outer peripheral surface 19 Inner peripheral surface 21 Outer peripheral surface 22 Inner cylinder large diameter inner peripheral surface 23 Inner seal ring 35 Connecting means 41 Bush one end surface 42 Bush other end surface 43 Slit 44 Bush inner peripheral surface 45 Bush small diameter outer peripheral surface 46 Bush inclined outer peripheral surface 47 Bush large outer peripheral surface 48 Bush recess 61 Inner cylinder one end surface 62 Inner cylinder outer peripheral surface 63 Inner cylinder inner peripheral surface 64 Inner cylinder larger diameter inner peripheral surface 65 Inner cylinder large-diameter inner peripheral surface 66 Inner cylinder intermediate end surface 67 Inner cylinder intermediate inner peripheral surface 68, 69 Inner cylinder recess 71 Inner cylinder other end surface 72 Inner cylinder outer stepped end surface 3 inner cylinder inner stepped end face

Claims (4)

内部にラック軸が挿通される外筒の一端部の外筒小径内周面に嵌装されると共に外筒の内部に挿通されたラック軸の一端部が貫通される縮径自在な合成樹脂製のブッシュと、外筒の内部に挿通されたラック軸の一端部が貫通されると共にブッシュの軸方向の一端に連接されて外筒の一端部の外筒大径内周面に嵌装される内筒と、ブッシュ及び内筒を互いに連結する連結手段とを具備しており、ブッシュは、軸方向のブッシュ一端面から軸方向のブッシュ他端面まで伸びたスリットと、ラック軸の外周面に摺動自在に接触する円筒状のブッシュ内周面と、外筒小径内周面に対面する円筒状のブッシュ小径外周面と、外筒小径内周面に弾性的に押圧接触する外側の小径シールリングを受容するようにブッシュ小径外周面に形成されている環状のブッシュ溝と、ブッシュ小径外周面に環状のブッシュ傾斜外周面を介して軸方向において連接されていると共に外筒大径内周面に対面する円筒状のブッシュ大径外周面と、ブッシュ他端面からブッシュ一端面に向かって夫々軸方向に伸びていると共に軸心周りの方向において配列された複数個のブッシュ凹所とを具備しており、内筒は、ブッシュ他端面に接触する軸方向の内筒一端面と、外筒大径内周面に嵌着される内筒外周面と、外筒大径内周面に弾性的に押圧接触する外側の大径シールリングを受容するように内筒外周面に形成された環状の内筒溝と、ラック軸の外周面に摺動自在に接触する円筒状の内筒内周面と、内筒一端面及び内筒内周面の間に配されていると共に内筒内周面よりも大径であって、ラック軸の外周面に内周面で摺動自在に接触する内側シールリングの外周面が接触する内筒大径内周面とを具備しているブッシュ軸受。   Made of a synthetic resin that can be reduced in diameter and is fitted on the inner peripheral surface of the small outer diameter of the outer cylinder of one end of the outer cylinder through which the rack shaft is inserted, and through which one end of the rack shaft is inserted through the outer cylinder. And one end of the rack shaft inserted through the inside of the outer cylinder are penetrated and connected to one end of the bush in the axial direction and are fitted to the outer cylinder large-diameter inner peripheral surface of one end of the outer cylinder. An inner cylinder, and a bush and a coupling means for coupling the inner cylinder to each other. The bush is slid onto the outer peripheral surface of the rack shaft and a slit extending from one axial end of the bush to the other axial end of the bush. Cylindrical bush inner peripheral surface that contacts freely, cylindrical bush small-diameter outer peripheral surface facing outer cylindrical small-diameter inner peripheral surface, and outer small-diameter seal ring that elastically presses and contacts outer cylindrical small-diameter inner peripheral surface An annular bush formed on the outer peripheral surface of the bush A cylindrical bush large-diameter outer surface that is axially connected to the small-diameter outer surface of the bush via an annular inclined outer peripheral surface of the bush and faces the large-diameter inner peripheral surface of the outer cylinder, and the other end surface of the bush A plurality of bush recesses extending in the axial direction toward the one end surface of the bush and arranged in the direction around the shaft center are provided, and the inner cylinder is in the axial direction in contact with the other end surface of the bush. One end surface of the cylinder, an outer peripheral surface of the inner cylinder that is fitted on the inner peripheral surface of the outer cylinder, and an inner cylinder that receives the outer large-diameter seal ring that is elastically pressed into contact with the outer diameter of the outer cylinder. An annular inner cylinder groove formed on the outer circumferential surface, a cylindrical inner cylinder inner circumferential surface that slidably contacts the outer circumferential surface of the rack shaft, and an inner cylinder one end surface and an inner cylinder inner circumferential surface. In addition, it has a diameter larger than the inner peripheral surface of the inner cylinder, and slides on the outer peripheral surface of the rack shaft on the inner peripheral surface. Bush bearing outer circumferential surface of the inner sealing ring is provided with an inner cylindrical large-diameter inner peripheral surface in contact in contact with. 内筒は、内筒一端面において開口する一端から軸方向に伸びていると共に軸心周りの方向において角度間隔をもって配列された複数の内筒凹所を有している請求項１に記載のブッシュ軸受。   2. The bush according to claim 1, wherein the inner cylinder has a plurality of inner cylinder recesses extending in an axial direction from one end opened at one end surface of the inner cylinder and arranged at angular intervals in a direction around the axis. bearing. 内筒は、内筒内周面の径よりも大径の円筒状の他の内筒大径内周面と、この他の内筒大径内周面の軸方向の一端に外周縁で連接された環状の内筒中間端面と、内筒中間端面において開口する一端から軸方向に夫々伸びていると共に軸心周りの方向に等角度間隔をもって配列されている複数の他の内筒凹所を有している請求項１又は２に記載のブッシュ軸受。   The inner cylinder is connected at the outer peripheral edge to the other inner cylinder large-diameter inner peripheral surface having a larger diameter than the inner peripheral surface of the inner cylinder and one axial end of the other inner-large-diameter inner peripheral surface. And a plurality of other inner cylinder recesses extending in the axial direction from one end opened at the inner cylinder intermediate end face and arranged at equal angular intervals in the direction around the axis. The bushing bearing according to claim 1 or 2 having. 油液が充填された内部にラック軸が挿通される外筒と、外筒の内部に挿通されたラック軸の一端部を摺動自在に支持するべく、外筒小径内周面及び外筒大径内周面に嵌装された請求項１から３のいずれか一項に記載のブッシュ軸受と、ブッシュ溝に受容された小径シールリングと、内筒溝に受容された大径シールリングと、ラック軸の外周面に内周面で摺動自在に接触すると共に外周面が内筒大径内周面に接触する内側シールリングとを有した自動車のラックピニオン式油圧パワーステアリング装置。   An outer cylinder through which the rack shaft is inserted into the oil-filled interior, and an outer cylinder small-diameter inner peripheral surface and an outer cylinder large in order to slidably support one end of the rack shaft inserted into the outer cylinder. The bush bearing according to any one of claims 1 to 3, fitted on a radially inner peripheral surface, a small-diameter seal ring received in the bush groove, a large-diameter seal ring received in the inner cylindrical groove, A rack and pinion type hydraulic power steering apparatus for an automobile having an inner seal ring that slidably contacts an outer peripheral surface of a rack shaft on an inner peripheral surface and an outer peripheral surface contacts an inner peripheral surface of a large-diameter inner cylinder.

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