JP2014004884A

JP2014004884A - Rack and pinion type steering device

Info

Publication number: JP2014004884A
Application number: JP2012140709A
Authority: JP
Inventors: Masahito Sasaki; 将人佐々木
Original assignee: JTEKT Corp
Current assignee: JTEKT Corp
Priority date: 2012-06-22
Filing date: 2012-06-22
Publication date: 2014-01-16

Abstract

PROBLEM TO BE SOLVED: To provide a rack and pinion type steering device which prevents hitting sounds and wear of a rack shaft support member due to the contact therewith by axial movements of the rack shaft support member and swinging of the rack shaft support member which occurs in a state where an axis line of the rack shaft support member inclines relative to an axis line of a holding hole.SOLUTION: A rack and pinion type steering device includes: a rack shaft support member which slidably supports a rack shaft; and a sealing member 35 provided at a position where the sealing member 35 closes a holding hole 31. In the rack and pinion type steering device, a flat first surface 352A, where no oil groove is formed, is provided on a line parallel with the rack shaft passing through a center axis of the rack shaft support member in at least one of end surfaces of the rack shaft support member and the sealing member 35 which face each other, and a second surface 352B, in which oil grooves are formed at parts of a flat surface, is provided on a line perpendicular to the rack shaft passing through the center axis of the rack shaft support member.

Description

本発明は、ラックアンドピニオン式ステリング装置に関する。 The present invention relates to a rack and pinion type steering device.

従来、車両の舵取りを行うステアリング装置として、操舵部材の回転操作に応じたピニオンの回転を、該ピニオンに噛合するラックを有するラック軸の軸長方向の移動に変換し、ラック軸の両端に連結された左右の前輪を押し引きして舵取りをおこなうように構成されたラックアンドピニオン式のステアリング装置が広く採用されている。このラックアンドピニオン式のステアリング装置は、一般的に、ラック軸に弾性接触し、前記噛合い部に与圧を加えるラック軸支持部材を備えている。また、前記ラック及びピニオンは、大容量の負荷伝達とすべく、噛合い率が大きいはす歯に夫々形成してある。 Conventionally, as a steering device for steering a vehicle, the rotation of a pinion according to the rotation operation of a steering member is converted into movement in the axial direction of a rack shaft having a rack meshing with the pinion and connected to both ends of the rack shaft A rack and pinion type steering device configured to push and pull the left and right front wheels to steer is widely used. This rack-and-pinion steering device generally includes a rack shaft support member that elastically contacts the rack shaft and applies pressure to the meshing portion. The rack and pinion are respectively formed on a tooth having a large meshing rate so as to transmit a large-capacity load.

このようなラックアンドピニオン式のステアリング装置においては、操舵時にラック及びピニオンの噛合いに伴ってラック軸支持部材の軸動と、ラック軸支持部材の径方向の移動が同時に発生する。
さらに、ラック軸とピニオンとの噛み合い反力が大きいとき（高負荷時）に、ラック軸支持部材の後面が、封止部材の前面に接触するようになっている。通常は、ラック軸支持部材の軸線が保持孔の軸線に対して平行な状態で、ラック軸支持部材の後面が封止部材の前面に面当たりする。 In such a rack and pinion type steering device, the axial movement of the rack shaft support member and the radial movement of the rack shaft support member occur simultaneously with the engagement of the rack and the pinion during steering.
Further, when the reaction force between the rack shaft and the pinion is large (during high load), the rear surface of the rack shaft support member comes into contact with the front surface of the sealing member. Usually, the rear surface of the rack shaft support member comes into contact with the front surface of the sealing member in a state where the axis of the rack shaft support member is parallel to the axis of the holding hole.

またラック軸とピニオンとの噛み合い反力が大きいとき（高負荷時）に急激なハンドル操作がある場合は、ラック軸支持部材の軸線が保持孔の軸線に対して傾いた状態で、ラック軸支持部材の後面の外縁の一部と封止部材の前面の一部とが互いに局部的に接触して、この接触箇所の摩擦力を上回る外力がラック軸支持部材に作用して初めて、傾いたラック軸支持部材の後面の外縁の一部が封止部材の前面に沿って摺動し、その後、ラック軸支持部材の後面が封止部材の前面に面当たり状態になる。この面当たり時に大きな打音が発生する。 Also, when there is a sudden handle operation when the meshing reaction force between the rack shaft and the pinion is large (high load), the rack shaft support is supported with the axis of the rack shaft support member tilted with respect to the axis of the holding hole. A tilted rack is only when a part of the outer edge of the rear surface of the member and a part of the front surface of the sealing member are in local contact with each other and an external force exceeding the frictional force at the contact point acts on the rack shaft support member. A part of the outer edge of the rear surface of the shaft support member slides along the front surface of the sealing member, and then the rear surface of the rack shaft support member comes into contact with the front surface of the sealing member. A loud hitting sound is generated when hitting this surface.

ラック軸支持部材の後面の外縁の一部と封止部材の前面の一部とが互いに局部的に接触する箇所の摩擦力を下げるために、上記ラック軸支持部材の後面に潤滑剤を保持する油溝を放射状に複数形成し、ラック軸支持部材の後面が封止部材の前面に面当たりする時の打音を下げている。（特許文献１） A lubricant is held on the rear surface of the rack shaft support member in order to reduce the frictional force at a portion where a part of the outer edge of the rear surface of the rack shaft support member and a part of the front surface of the sealing member are locally in contact with each other. A plurality of oil grooves are formed radially to reduce the sound of hitting when the rear surface of the rack shaft support member hits the front surface of the sealing member. (Patent Document 1)

特開２０１１−７９４３０号公報JP 2011-79430 A

ラック軸支持部材は、ラック軸の軸線と直角方向に傾くため、ラック軸支持部材の後面の中でも、ラック軸支持部材の中心軸を通りラック軸の軸線と直角方向にある面の油が押し退けられ、ラック軸支持部材の中心軸を通りラック軸の軸線方向にある面へ油が溜まる。ラック軸支持部材の中心軸を通りラック軸の軸線方向にある面に油溝があるため、なおさら油が溜まりやすくなり、ラック軸支持部材の中心軸を通りラック軸の軸線と直角方向にある油溝の油が枯渇して打音が発生しやすい問題があった。そこで本発明の目的は、ラック軸支持部材の中心軸を通りラック軸の軸線と直角方向にある油溝の油が枯渇しないようにして、打音を防ぐことができるラックアンドピニオン式ステアリング装置を提供することである。 Since the rack shaft support member is inclined in a direction perpendicular to the axis of the rack shaft, the oil on the rear surface of the rack shaft support member passing through the central axis of the rack shaft support member and perpendicular to the axis of the rack shaft is pushed away. Then, oil accumulates on the surface in the axial direction of the rack shaft through the central axis of the rack shaft support member. Since there is an oil groove on the surface in the axial direction of the rack shaft that passes through the central axis of the rack shaft support member, it is easier for oil to collect, and the oil that passes through the central axis of the rack shaft support member and is perpendicular to the axis of the rack shaft. There was a problem that the oil in the groove was depleted and a hitting sound was likely to occur. SUMMARY OF THE INVENTION An object of the present invention is to provide a rack and pinion type steering device capable of preventing sound from hitting so that oil in an oil groove passing through the central axis of the rack shaft support member and perpendicular to the axis of the rack shaft does not run out. Is to provide.

上記課題を解決するために、請求項１に記載の発明は、軸方向に進退するラック軸と、このラック軸に噛合するピニオン軸と、前記ラック軸を軸方向に進退可能に支持するとともに前記ピニオン軸を回転可能に支持し、前記ラック軸を挟んで前記ピニオン軸と反対側に保持孔を形成したハウジングと、前記保持穴に摺動可能に収容され前記ラック軸を摺動可能に支持するラック軸支持部材と、前記保持孔の閉止する位置に設けられた封止部材と、前記封止部材および前記ラック軸支持部材間に介挿され、前記ラック軸支持部材を前記ラック軸側に付勢する付勢部材とを備えたラックアンドピニオン式ステアリング装置において、前記ラック軸支持部材および前記封止部材の互いに向かい合う端面の少なくとも一方に、前記ラック軸支持部材の中心軸を通る前記ラック軸と平行な線上に油溝の無い平らな第１面を設け、前記ラック軸支持部材の中心軸を通る前記ラック軸と直角な線上に平らな面の一部に油溝を形成した第２面を設けたことを要旨としている。 In order to solve the above problem, the invention according to claim 1 is directed to a rack shaft that advances and retreats in the axial direction, a pinion shaft that meshes with the rack shaft, and supports the rack shaft so that it can advance and retreat in the axial direction. A pinion shaft is rotatably supported, a housing in which a holding hole is formed on the opposite side of the pinion shaft across the rack shaft, and a rack shaft that is slidably received in the holding hole and slidably supports the rack shaft. A rack shaft support member, a sealing member provided at a position where the holding hole is closed, and the rack shaft support member interposed between the sealing member and the rack shaft support member, and attached to the rack shaft side. In the rack and pinion type steering apparatus including a biasing member that biases, at least one of the end surfaces of the rack shaft support member and the sealing member facing each other is provided with the rack shaft support member. A flat first surface without an oil groove is provided on a line parallel to the rack axis passing through the mandrel, and oil is applied to a part of the flat surface on a line perpendicular to the rack axis passing through the central axis of the rack shaft support member. The gist is that a second surface having grooves is provided.

本発明によると、ラック軸とピニオンとの噛み合い反力が大きいときに、ラック軸支持部材の軸線が保持孔の軸線に対して傾いた状態でラック軸と直角方向でかつラック軸支持部材の径方向に大きい移動を繰り返した場合、油溝部のない平坦部への潤滑剤の移動が発生しないため、いつまでもラック軸と直角な線上の油溝部で潤滑剤の枯渇がなく、潤滑剤により、ラック軸支持部材の端部が封止部材に対してスムーズに摺動でき、長期に保持孔内で傾いたラック軸支持部材の後面の外縁の一部と封止部材の前面の一部とが局部的に接触することを防止して、打音および摩耗を防ぐことができるラックアンドピニオン式ステアリング装置を提供できる。 According to the present invention, when the meshing reaction force between the rack shaft and the pinion is large, the diameter of the rack shaft support member is perpendicular to the rack shaft and the axis of the rack shaft support member is inclined with respect to the axis of the holding hole. When a large movement in the direction is repeated, the lubricant does not move to the flat part without the oil groove part.Therefore, there is no depletion of the lubricant in the oil groove part on the line perpendicular to the rack axis. The end of the support member can slide smoothly with respect to the sealing member, and a part of the outer edge of the rear surface of the rack shaft support member inclined in the holding hole for a long time and a part of the front surface of the sealing member are localized. It is possible to provide a rack and pinion type steering apparatus that can prevent hitting and wear by preventing contact with the wheel.

請求項２に記載の発明は、油溝は、ラック軸の軸線と直角方向に延び、ラック軸の軸線方向に複数並行に配置されていることを要旨としている。そのため、ラック軸と直角方向でかつラック軸支持部材の径方向に大きい移動を繰り返した場合、必要な油溝部にのみ潤滑剤がとどまり、ラック支持部材の挙動に合わせて潤滑剤が効果的に作用するため、付勢部材の端部が封止部材に対してスムーズに摺動でき、長期に保持孔内で傾いたラック軸支持部材の後面の外縁の一部と封止部材の前面の一部とが局部的に接触することを防止して、接触による打音および摩耗を防ぐことができるラックアンドピニオン式ステアリング装置を提供できる。 The gist of the invention described in claim 2 is that the oil grooves extend in a direction perpendicular to the axis of the rack shaft and are arranged in parallel in the axial direction of the rack shaft. For this reason, when large movements in the direction perpendicular to the rack shaft and in the radial direction of the rack shaft support member are repeated, the lubricant stays only in the necessary oil grooves, and the lubricant acts effectively according to the behavior of the rack support member. Therefore, the end of the biasing member can slide smoothly with respect to the sealing member, and a part of the outer edge of the rear surface of the rack shaft support member that is inclined in the holding hole for a long period It is possible to provide a rack-and-pinion type steering device that can prevent contact with each other and prevent hitting sound and wear due to contact.

請求項３に記載の発明は、油溝は、ラック軸支持部材の外径側に向かって溝深さが浅くなる形状を有することを要旨としている。 The gist of the invention described in claim 3 is that the oil groove has a shape in which the groove depth decreases toward the outer diameter side of the rack shaft support member.

本発明によると、ラック軸の軸線と直角方向でかつラック軸支持部材の径方向に大きい移動を繰り返した場合、ラック軸支持部材の径方向の往復動により潤滑剤の油膜圧力を発生する油溝と潤滑剤を保持する油溝が円周状幅方向で潤滑剤の通路が狭くなるように形成設置されているため、潤滑剤の油膜圧力が発生して、長期に接触による打音および摩耗を防ぐことができるラックアンドピニオン式ステアリング装置を提供できる。 According to the present invention, when a large movement in the direction perpendicular to the axis of the rack shaft and in the radial direction of the rack shaft support member is repeated, the oil groove that generates the oil film pressure of the lubricant by the reciprocating motion of the rack shaft support member in the radial direction. And the oil grooves that hold the lubricant are formed and installed so that the passage of the lubricant is narrow in the circumferential width direction. A rack and pinion type steering device that can be prevented can be provided.

本発明の構造によれば、ラック軸支持部材の軸動とラック軸支持部材の軸線が保持孔の軸線に対して傾いた揺動で、ラック軸支持部材の接触による打音および摩耗を防ぐことができるラックアンドピニオン式ステアリングを提供できる。 According to the structure of the present invention, the axial movement of the rack shaft support member and the swing of the axis of the rack shaft support member tilted with respect to the axis of the holding hole can prevent hitting and wear caused by contact of the rack shaft support member. Can provide rack and pinion type steering.

本発明の第１の実施形態かかるラックアンドピニオン式ステリング装置のコラム部分を含めた概略構成図1 is a schematic configuration diagram including a column portion of a rack and pinion type stelling device according to a first embodiment of the present invention. 本発明の第１の実施形態かかるラックアンドピニオン式ステリング装置の操舵機構部分の断面図Sectional drawing of the steering mechanism part of the rack and pinion type | formula steering apparatus concerning the 1st Embodiment of this invention 本発明の第１の実施形態かかる図２の要部Ａ１の拡大図The enlarged view of the principal part A1 of FIG. 2 concerning the 1st Embodiment of this invention. 本発明の第１の実施形態かかる図２のIVＡ−IVＡ線断面図Sectional view taken along the line IVA-IVA of FIG. 2 according to the first embodiment of the present invention. 本発明の第１の実施形態かかる図４のIVＢ−IVＢ線拡大断面図The IVB-IVB line expanded sectional view of Drawing 4 concerning a 1st embodiment of the present invention. 本発明の第１の実施形態かかる図４のＣ−Ｃ線拡大断面図FIG. 4 is an enlarged sectional view taken along line CC of FIG. 4 according to the first embodiment of the present invention. 本発明の第２の実施形態かかる図２の要部Ａ１の拡大図The enlarged view of the principal part A1 of FIG. 2 concerning the 2nd Embodiment of this invention. 本発明の第２の実施形態かかる図７のＤ−Ｄ線拡大断面図The DD sectional view of FIG. 7 according to the second embodiment of the present invention.

以下では、この発明の実施の形態を、添付図面を参照して詳細に説明する。本実施形態では、ラック軸支持装置がラックアンドピニオン式ステリング装置としての電動パワーステアリング装置に用いられる場合に則して説明するが、ラック軸支持装置が、例えば、マニュアル操舵のラックアンドピニオン式ステリング装置に適用されてもよい。
図１を参照して、ラックアンドピニオン式ステリング装置１は、ステアリングホイール等の操舵部材２に連結しているステアリングシャフト３と、ステアリングシャフト３に自在継手４を介して連結された中間軸５と、中間軸５に自在継手６を介して連結されたピニオン軸７と、ピニオン軸７に設けられたピニオン８に噛み合うラック９を有して車両の左右方向に延びる転舵軸としてのラック軸１０とを有している。 Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present embodiment, the case where the rack shaft support device is used in an electric power steering device as a rack and pinion type steering device will be described. However, the rack shaft support device is, for example, a manual steering rack and pinion type steering device. It may be applied to the device.
Referring to FIG. 1, a rack and pinion type steering device 1 includes a steering shaft 3 connected to a steering member 2 such as a steering wheel, and an intermediate shaft 5 connected to the steering shaft 3 via a universal joint 4. A rack shaft 10 as a turning shaft having a pinion shaft 7 connected to the intermediate shaft 5 via a universal joint 6 and a rack 9 meshing with a pinion 8 provided on the pinion shaft 7 and extending in the left-right direction of the vehicle. And have.

ピニオン軸７およびラック軸１０によりラックアンドピニオン機構からなる操舵機構１１が構成されている。ラック軸１０は、車体１２に固定されるラックハウジング１３内に図示しない複数の軸受を介して直線往復可能に支持されている。ラック軸１０には、一対のタイロッド１４が結合されている。各タイロッド１４は対応するナックルアーム（図示せず）を介して対応する転舵輪１６に連結されている。 The pinion shaft 7 and the rack shaft 10 constitute a steering mechanism 11 composed of a rack and pinion mechanism. The rack shaft 10 is supported in a rack housing 13 fixed to the vehicle body 12 so as to be linearly reciprocable via a plurality of bearings (not shown). A pair of tie rods 14 are coupled to the rack shaft 10. Each tie rod 14 is connected to a corresponding steered wheel 16 via a corresponding knuckle arm (not shown).

操舵部材２が操作されてステアリングシャフト３が回転されると、この回転がピニオン８およびラック９によって、自動車の左右方向に沿ってのラック軸１０の直線運動（ラック軸１０の軸方向移動に相当する。）に変換される。これにより、転舵輪１６の転舵が達成される。
ステアリングシャフト３は、操舵部材２に連なる入力軸１７と、ピニオン軸７に連なる出力軸１８とに分割されている。これら入力軸１７および出力軸１８はトーションバー１９を介して同一の軸線上で互いに連結されている。入力軸１７に操舵トルクが入力されたときに、トーションバー１９が弾性ねじり変形し、これにより、入力軸１７および出力軸１８が相対回転するようになっている。 When the steering member 2 is operated and the steering shaft 3 is rotated, this rotation is caused by the pinion 8 and the rack 9 to linearly move the rack shaft 10 along the left-right direction of the automobile (corresponding to the axial movement of the rack shaft 10). Is converted to Thereby, the turning of the steered wheels 16 is achieved.
The steering shaft 3 is divided into an input shaft 17 connected to the steering member 2 and an output shaft 18 connected to the pinion shaft 7. The input shaft 17 and the output shaft 18 are connected to each other on the same axis via a torsion bar 19. When steering torque is input to the input shaft 17, the torsion bar 19 is elastically torsionally deformed, whereby the input shaft 17 and the output shaft 18 are rotated relative to each other.

ラックアンドピニオン式ステリング装置には、トーションバー１９を介して互いに連結された入力軸１７および出力軸１８の間の相対回転変位量により操舵トルクを検出するトルクセンサ２０が設けられている。また、車速を検出するための車速センサ２１が設けられている。また、制御装置としてのＥＣＵ（Electronic Control Unit ：電子制御ユニット）２２が設けられている。また、操舵補助力を発生させるための電動モータ２３と、この電動モータ２３の出力回転を減速する減速機２４とが設けられている。 The rack and pinion type steering device is provided with a torque sensor 20 that detects a steering torque based on a relative rotational displacement amount between an input shaft 17 and an output shaft 18 connected to each other via a torsion bar 19. A vehicle speed sensor 21 for detecting the vehicle speed is also provided. An ECU (Electronic Control Unit) 22 is provided as a control device. An electric motor 23 for generating a steering assist force and a speed reducer 24 for reducing the output rotation of the electric motor 23 are provided.

トルクセンサ２０および車速センサ２１からの検出信号が、ＥＣＵ２２に入力されるようになっている。ＥＣＵ２２は、トルク検出結果や車速検出結果等に基づいて、操舵補助用の電動モータ２３を制御する。電動モータ２３の出力回転が減速機２４を介して減速されてピニオン軸７に伝達され、ラック軸１０の直線運動に変換されて、操舵が補助されるようになっている。 Detection signals from the torque sensor 20 and the vehicle speed sensor 21 are input to the ECU 22. The ECU 22 controls the steering assisting electric motor 23 based on the torque detection result, the vehicle speed detection result, and the like. The output rotation of the electric motor 23 is decelerated via the speed reducer 24, transmitted to the pinion shaft 7, and converted into a linear motion of the rack shaft 10, thereby assisting in steering.

図２を参照して、ラックアンドピニオン式ステリング装置１は、ピニオン軸７を回転可能に支持する一対の軸受２６，２７と、ラック軸１０を支持するラック軸支持装置２８と、ピニオン軸７の一部および一対の軸受２６，２７を収容するピニオンハウジング２９と、ラック軸支持装置２８の少なくとも一部を収容するハウジング３０とを有している。 Referring to FIG. 2, the rack and pinion type stelling device 1 includes a pair of bearings 26 and 27 that rotatably support the pinion shaft 7, a rack shaft support device 28 that supports the rack shaft 10, and a pinion shaft 7. A pinion housing 29 that accommodates a part and a pair of bearings 26 and 27 and a housing 30 that accommodates at least a part of the rack shaft support device 28 are provided.

図１および図２を参照して、ラックハウジング１３の少なくとも一部と、ハウジング３０と、ピニオンハウジング２９とは、互いに交差状に配置され、単一材料により互いに一体に形成されている。すなわち、ピニオンハウジング２９は、筒形状をなしており、ラックハウジング１３が延びる方向（図２の紙面垂直方向に相当する。）とは交差する方向に平行に延びている。ハウジング３０は、筒状をなしており、ラック軸１０を隔ててピニオン軸７とは反対側に配置されている。ハウジング３０は、保持孔３１を有している。 Referring to FIGS. 1 and 2, at least a part of rack housing 13, housing 30, and pinion housing 29 are arranged so as to intersect each other and are integrally formed with a single material. That is, the pinion housing 29 has a cylindrical shape and extends in parallel to a direction intersecting with a direction in which the rack housing 13 extends (corresponding to a direction perpendicular to the paper surface of FIG. 2). The housing 30 has a cylindrical shape, and is disposed on the opposite side of the pinion shaft 7 with the rack shaft 10 therebetween. The housing 30 has a holding hole 31.

ハウジング３０および保持孔３１はともに、ピニオン軸７の軸方向Ｚ２およびラック軸１０の軸方向Ｚ１にともに直交する方向Ｚ３に延びている。互いに一体に形成されたラックハウジング１３の一部とピニオンハウジング２９とハウジング３０とにより、ピニオン軸７およびラック軸１０が互いに噛み合う部分が収容されている。ラック軸１０は、図２の紙面垂直方向に延びている。ラック９は、はすばラックからなる。このはすばラックが、はすば歯車からなるピニオン８と互いに噛み合っている。ラック軸１０は、断面Ｄ字形形状をなす。ラック軸１０は、ラック９とは反対側に円筒面の一部からなる背面を有している。 Both the housing 30 and the holding hole 31 extend in a direction Z3 orthogonal to both the axial direction Z2 of the pinion shaft 7 and the axial direction Z1 of the rack shaft 10. A portion where the pinion shaft 7 and the rack shaft 10 mesh with each other is accommodated by a part of the rack housing 13 formed integrally with each other, the pinion housing 29 and the housing 30. The rack shaft 10 extends in the direction perpendicular to the paper surface of FIG. The rack 9 is a helical rack. The helical rack meshes with the pinion 8 formed of a helical gear. The rack shaft 10 has a D-shaped cross section. The rack shaft 10 has a back surface formed of a part of a cylindrical surface on the side opposite to the rack 9.

図２を参照して、ラック軸支持装置２８は、ラック軸１０を摺動可能に支持する円筒状のラック軸支持部材３４を有している。ラック軸支持部材３４は、ハウジング３０に形成された保持孔３１内に保持孔３１の深さ方向（ハウジング３０が延びる方向Ｚ３に相当し、以下、深さ方向Ｚ３ともいう。）に摺動可能に収容されている。また、ラック軸支持装置２８は、保持孔３１の入口３１１に固定されておりこの入口３１１を封止する封止部材３５と、封止部材３５によって支持されラック軸支持部材３４をラック軸１０側に付勢する付勢部材３６とを有している。 Referring to FIG. 2, the rack shaft support device 28 includes a cylindrical rack shaft support member 34 that slidably supports the rack shaft 10. The rack shaft support member 34 is slidable in the holding hole 31 formed in the housing 30 in the depth direction of the holding hole 31 (corresponding to the direction Z3 in which the housing 30 extends, hereinafter also referred to as depth direction Z3). Is housed in. The rack shaft support device 28 is fixed to the inlet 311 of the holding hole 31, and the sealing member 35 that seals the inlet 311 and the rack shaft support member 34 that is supported by the sealing member 35 on the rack shaft 10 side. And an urging member 36 for urging the lens.

ハウジング３０の保持孔３１は、円孔からなる。保持孔３１は、入口３１１を有している。保持孔３１の内周は、ラック軸支持部材３４を保持する円筒面により形成された保持部３１２と、封止部材３５を螺合する雌ねじ３１３とを有している。雌ねじ３１３は、入口３１１を形成するとともに、入口３１１と保持部３１２との間に形成されている。封止部材３５は、筒形状をなしており、アルミニウム合金により形成されている。封止部材３５の外周に、雄ねじ３５１が形成されている。雄ねじ３５１は、右ねじにより形成されており、保持孔３１の雌ねじ３１３にねじ嵌合されている。また、雄ねじ３５１には、ロックナット３７がねじ嵌合されている。ロックナット３７がハウジング３０の端面に押圧されることにより、封止部材３５がハウジング３０に止定されている。封止部材３５の後面３５３には、多角形形状の孔からなる工具係合孔３５４が設けられている。 The holding hole 31 of the housing 30 is a circular hole. The holding hole 31 has an inlet 311. The inner periphery of the holding hole 31 has a holding portion 312 formed by a cylindrical surface that holds the rack shaft support member 34, and a female screw 313 that screws the sealing member 35. The female screw 313 forms the inlet 311 and is formed between the inlet 311 and the holding portion 312. The sealing member 35 has a cylindrical shape and is formed of an aluminum alloy. A male screw 351 is formed on the outer periphery of the sealing member 35. The male screw 351 is formed by a right screw, and is screwed into the female screw 313 of the holding hole 31. A lock nut 37 is screwed onto the male screw 351. The sealing member 35 is fixed to the housing 30 by the lock nut 37 being pressed against the end surface of the housing 30. On the rear surface 353 of the sealing member 35, a tool engagement hole 354 made of a polygonal hole is provided.

付勢部材３６は、例えば、圧縮コイルばねからなる。この圧縮コイルばねは、弾性圧縮変形を受けた状態で、封止部材３５とラック軸支持部材３４との間に介在している。付勢部材３６は、ラック軸支持部材３４をラック軸１０側へ弾性的に付勢している。ラック軸支持部材３４は、保持孔３１内に収容されており、この保持孔３１の深さ方向Ｚ３に進退可能に保持孔３１に保持されている。ラック軸支持部材３４は、アルミニウム合金により形成されており、略円柱形状をなしている。この略円柱形状の中心軸線が、保持孔３１の中心軸線に沿うように配置されている。 The biasing member 36 is made of a compression coil spring, for example. The compression coil spring is interposed between the sealing member 35 and the rack shaft support member 34 in a state of undergoing elastic compression deformation. The biasing member 36 elastically biases the rack shaft support member 34 toward the rack shaft 10 side. The rack shaft support member 34 is accommodated in the holding hole 31 and is held in the holding hole 31 so as to be able to advance and retreat in the depth direction Z3 of the holding hole 31. The rack shaft support member 34 is made of an aluminum alloy and has a substantially cylindrical shape. The substantially cylindrical central axis is arranged along the central axis of the holding hole 31.

ラック軸支持部材３４は、後面３４３を有している。後面３４３は、封止部材３５の前面３５２に対向して配置されている。後面３４３は、付勢部材３６を受ける領域として、付勢部材３６の少なくとも一部を収容する凹部３４５を有している。この凹部３４５の底が、付勢部材３６を受けている。
図３は、図２の要部Ａ１の拡大図であり、保持孔３１の中心線が左右に延びるように図示するとともに、保持孔３１の中心線に対して半断面表示されている。図２および図３を参照して、ラック軸支持部材３４の外周面は、円筒面により形成されており、複数（例えば２個）の周溝３４８を有している。複数の周溝３４８は、深さ方向Ｚ３に互いに離隔して配置されている。各周溝３４８には、環状の弾性部材、例えばＯリング３８が装着されている。Ｏリング３８は、保持孔３１の径方向に弾性圧縮変形した状態で、周溝３４８の底と保持孔３１の内周との間に介在している。これにより、ラック軸支持部材３４は、保持孔３１に弾性支持されている。また、ラック軸支持部材３４の外周面と保持孔３１の内周面との間の所定量の隙間に、潤滑剤（図示せず）が保持されている。 The rack shaft support member 34 has a rear surface 343. The rear surface 343 is disposed to face the front surface 352 of the sealing member 35. The rear surface 343 has a recess 345 that accommodates at least a part of the urging member 36 as a region for receiving the urging member 36. The bottom of the recess 345 receives the biasing member 36.
FIG. 3 is an enlarged view of the main part A1 of FIG. 2 and 3, the outer peripheral surface of the rack shaft support member 34 is formed of a cylindrical surface, and has a plurality of (for example, two) peripheral grooves 348. The plurality of circumferential grooves 348 are spaced apart from each other in the depth direction Z3. Each circumferential groove 348 is provided with an annular elastic member, for example, an O-ring 38. The O-ring 38 is interposed between the bottom of the circumferential groove 348 and the inner periphery of the holding hole 31 in a state of being elastically compressed and deformed in the radial direction of the holding hole 31. As a result, the rack shaft support member 34 is elastically supported by the holding hole 31. A lubricant (not shown) is held in a predetermined amount of gap between the outer peripheral surface of the rack shaft support member 34 and the inner peripheral surface of the holding hole 31.

ラック軸支持部材３４は、ラック軸１０のラック９の背面を、このラック軸１０の軸方向Ｚ１（図２の紙面垂直方向に相当する。）に移動可能に支持している。ラック軸支持部材３４は、ラック軸１０の背面に対向して配置されておりラック軸１０の背面を軸方向Ｚ１に摺動可能に受ける受け部３４１を有している。受け部３４１は、凹湾曲面により形成され、ラック軸１０の背面の形状に概ね一致しており、例えば、部分円筒面に形成されている。 The rack shaft support member 34 supports the back surface of the rack 9 of the rack shaft 10 so as to be movable in the axial direction Z1 of the rack shaft 10 (corresponding to a direction perpendicular to the paper surface of FIG. 2). The rack shaft support member 34 is disposed to face the back surface of the rack shaft 10 and has a receiving portion 341 that receives the back surface of the rack shaft 10 so as to be slidable in the axial direction Z1. The receiving portion 341 is formed by a concave curved surface and substantially matches the shape of the back surface of the rack shaft 10, and is formed, for example, on a partial cylindrical surface.

図３と図４を参照して、ラック軸支持部材３４の後面３４３は、深さ方向Ｚ３に沿って見たときに凹部３４５を取り囲む環状の領域３４６を有している。環状の領域３４６は、平面をなす。一方、封止部材３５の前面３５２は、付勢部材３６を受ける領域３５５と、この領域３５５を取り囲む環状の領域３５６とを有している。 3 and 4, the rear surface 343 of the rack shaft support member 34 has an annular region 346 that surrounds the recess 345 when viewed along the depth direction Z3. The annular region 346 forms a plane. On the other hand, the front surface 352 of the sealing member 35 includes a region 355 that receives the biasing member 36 and an annular region 356 that surrounds the region 355.

図４には、環状の領域３５６は、周方向に関して一部のみ図示している。環状の領域３５６は、外周縁５０と、内周縁５１との間の領域である。また、環状の領域３５５は、その外周縁５２と、内周縁５３との間の領域である。ラック軸支持部材３４の環状の領域３４６と、封止部材３５の前面３５２の環状の領域３５６とが、深さ方向Ｚ３に沿って互いに対向している。環状の領域３４６，３５６の間隔は、所定の距離に設定されている。環状の領域３４６，３５６が互いに当接することにより、深さ方向Ｚ３に関してラック軸支持部材３４の移動量が規制されている。 FIG. 4 shows only a part of the annular region 356 in the circumferential direction. The annular region 356 is a region between the outer peripheral edge 50 and the inner peripheral edge 51. The annular region 355 is a region between the outer peripheral edge 52 and the inner peripheral edge 53. An annular region 346 of the rack shaft support member 34 and an annular region 356 of the front surface 352 of the sealing member 35 face each other along the depth direction Z3. The interval between the annular regions 346 and 356 is set to a predetermined distance. Since the annular regions 346 and 356 are in contact with each other, the amount of movement of the rack shaft support member 34 is regulated in the depth direction Z3.

図２と図３を参照して、ピニオン８とラック９との噛み合い反力がラック軸支持部材３４に作用したときには、付勢部材３６の付勢に抗して、ラック軸１０およびラック軸支持部材３４がピニオン軸７から遠ざかる向きに移動する。そして、噛み合い反力が大きいときには、ラック軸支持部材３４の後面３４３の環状の領域３４６と封止部材３５の前面３５２の環状の領域３５６とが互いに当接する。 2 and 3, when the meshing reaction force between pinion 8 and rack 9 acts on rack shaft support member 34, rack shaft 10 and rack shaft support are resisted against the bias of biasing member 36. The member 34 moves in a direction away from the pinion shaft 7. When the meshing reaction force is large, the annular region 346 of the rear surface 343 of the rack shaft support member 34 and the annular region 356 of the front surface 352 of the sealing member 35 come into contact with each other.

通常は、ラック軸支持部材３４の中心軸線が保持孔３１の中心軸線に対して平行な状態で、ラック軸支持部材３４の後面３４３が封止部材３５の前面３５２に面当たりする。一方で、ラック軸支持部材３４の中心軸線が保持孔３１の中心軸線に対して傾いた状態で、ラック軸支持部材３４の後面３４３の外縁の一部Ｐ１と封止部材３５の前面３５２の一部Ｐ２とが互いに局部的に接触する場合がある。この場合、噛み合い反力がラック軸支持部材３４に作用することにより、傾いたラック軸支持部材３４の後面３４３の外縁の一部Ｐ１が封止部材３５の前面３５２に沿って摺動し、その結果、ラック軸支持部材３４の後面３４３が封止部材３５の前面３５２に面当たりした上述の通常の状態になる。 Normally, the rear surface 343 of the rack shaft support member 34 contacts the front surface 352 of the sealing member 35 in a state where the center axis of the rack shaft support member 34 is parallel to the center axis of the holding hole 31. On the other hand, a part P1 of the outer edge of the rear surface 343 of the rack shaft support member 34 and one of the front surfaces 352 of the sealing member 35 in a state where the center axis of the rack shaft support member 34 is inclined with respect to the center axis of the holding hole 31. The part P2 may contact each other locally. In this case, when the meshing reaction force acts on the rack shaft support member 34, a part P1 of the outer edge of the rear surface 343 of the inclined rack shaft support member 34 slides along the front surface 352 of the sealing member 35, As a result, the rear surface 343 of the rack shaft support member 34 comes into contact with the front surface 352 of the sealing member 35 as described above.

このときに、従来のラック軸支持装置では、異音が生じやすくなっていた。すなわち、傾いた状態のラック軸支持部材３４の後面の外縁の一部と封止部材３５の前面との摺動抵抗が大きいので、ラック軸支持部材３４および封止部材３５の間の大きな静止摩擦力を上回る相当大きな力が作用するまでは、ラック軸支持部材３４は動き出すことができない。換言すれば、相当大きな力を受けて、ラック軸支持部材３４が、傾きを戻すように保持孔内で勢いよく動くことになる。その結果、例えばラック軸支持部材３４の後面と封止部材３５の前面とが勢いよく衝突し、異音が生じていた。 At this time, in the conventional rack shaft support device, abnormal noise is likely to occur. That is, since the sliding resistance between a part of the outer edge of the rear surface of the rack shaft support member 34 in an inclined state and the front surface of the sealing member 35 is large, a large static friction between the rack shaft support member 34 and the sealing member 35 is obtained. The rack shaft support member 34 cannot start moving until a considerably large force exceeding the force is applied. In other words, the rack shaft support member 34 is vigorously moved in the holding hole so as to return to the inclination by receiving a considerable force. As a result, for example, the rear surface of the rack shaft support member 34 and the front surface of the sealing member 35 collided vigorously, and abnormal noise was generated.

図２と図３を参照して、これに対して本実施形態では、ラック軸支持装置２８は、ラック軸支持部材３４および封止部材３５の環状の領域３４６，３５６間の摩擦を低減するための潤滑剤３９を収容した潤滑剤収容凹部として、封止部材３５の前面３５２に形成された複数の油溝４０を有している領域の第１面３５２Ｂをラック軸支持部材３４の中心軸を通る前記ラック軸１０と平行な線上に設け、平坦部の領域の第２面３５２Ａをラック軸支持部材３４の中心軸を通る前記ラック軸１０と直角な線上に有している。 With reference to FIGS. 2 and 3, on the other hand, in this embodiment, the rack shaft support device 28 reduces the friction between the annular regions 346 and 356 of the rack shaft support member 34 and the sealing member 35. The first surface 352B of the region having a plurality of oil grooves 40 formed on the front surface 352 of the sealing member 35 is used as the lubricant containing recess containing the lubricant 39, and the central axis of the rack shaft support member 34 is used as the central axis. The second surface 352A of the flat portion region is provided on a line perpendicular to the rack shaft 10 passing through the central axis of the rack shaft support member 34.

複数の油溝４０は、ラック軸１０の軸線と直角方向に平行としている。これにより、保持孔３１の周方向および径方向の両方向に関して広範囲にわたって、潤滑剤３９を環状の領域３４６，３５６内に供給できる。また、平行であれば、ラック支持部材３４の左右の揺動時に保持孔３１内でのラック軸支持部材３４の傾きを戻すように、ラック軸支持部材３４の後面３４３と封止部材３５の前面３５２との環状の領域３４６，３５６同士がスムーズに相対摺動できる。 The plurality of oil grooves 40 are parallel to the direction perpendicular to the axis of the rack shaft 10. Accordingly, the lubricant 39 can be supplied into the annular regions 346 and 356 over a wide range in both the circumferential direction and the radial direction of the holding hole 31. If they are parallel, the rear surface 343 of the rack shaft support member 34 and the front surface of the sealing member 35 are restored so that the inclination of the rack shaft support member 34 in the holding hole 31 is restored when the rack support member 34 swings left and right. The annular regions 346 and 356 with the 352 can smoothly slide relative to each other.

また、平行の複数の油溝４０は、保持孔３１の周方向に関する封止部材３５の位置にかかわらず、潤滑剤３９を、環状の領域３４６，３５６間に供給できる。また、本実施形態では、後述するように、組立時に保持孔３１への封止部材３５のねじ込み量を調整することによりラック軸支持部材３４の移動可能量を調整するようにしている。この場合には、封止部材３５の前面３５２とラック軸支持部材３４の後面３４３との環状の領域３４６，３５６同士を互いに近接させて相対回転させることになる。このときに、放射状の複数の油溝４０は、潤滑剤３９を、環状の領域３４６，３５６内の広い範囲に供給することができる。 The plurality of parallel oil grooves 40 can supply the lubricant 39 between the annular regions 346 and 356 regardless of the position of the sealing member 35 in the circumferential direction of the holding hole 31. Further, in the present embodiment, as described later, the movable amount of the rack shaft support member 34 is adjusted by adjusting the screwing amount of the sealing member 35 into the holding hole 31 during assembly. In this case, the annular regions 346 and 356 of the front surface 352 of the sealing member 35 and the rear surface 343 of the rack shaft support member 34 are brought close to each other and relatively rotated. At this time, the plurality of radial oil grooves 40 can supply the lubricant 39 to a wide range in the annular regions 346 and 356.

この効果を得るための平行の複数の油溝４０は、ラック軸支持部材３４の後面３４３および封止部材３５の前面３５２の少なくとも一方に形成されていればよい。また、平行をなす油溝４０の数は、５つの場合を図示しているが、例えば、３以上の８以外の数であってもよい。また、平行の複数の油溝４０のそれぞれは、本実施形態で図示したように保持孔３１の径方向に沿って延びていることや、保持孔３１の径方向に対して傾斜状に延びているのが（図示せず）、上述の効果を得るのに好ましい。 The plurality of parallel oil grooves 40 for obtaining this effect may be formed on at least one of the rear surface 343 of the rack shaft support member 34 and the front surface 352 of the sealing member 35. Moreover, although the number of the oil grooves 40 which make a parallel is illustrated in the case of five, it may be a number other than 8, for example, 3 or more. Each of the plurality of parallel oil grooves 40 extends along the radial direction of the holding hole 31 as illustrated in the present embodiment, or extends in an inclined manner with respect to the radial direction of the holding hole 31. It is preferable to obtain the above-mentioned effect (not shown).

具体的には、複数の油溝４０は、封止部材３５の中心軸線に沿って見たときに、この中心軸線とラック軸の軸線に平行に設置している。各油溝４０は、封止部材３５の径方向に沿って真直に所定長で延びている。油溝４０は、保持孔３１の径方向に関して相対的に内方に配置された内端４０１と、径方向に関して相対的に外方に配置された外端４０２とを有している。 Specifically, when viewed along the central axis of the sealing member 35, the plurality of oil grooves 40 are installed in parallel to the central axis and the rack axis. Each oil groove 40 extends straight along the radial direction of the sealing member 35 by a predetermined length. The oil groove 40 has an inner end 401 disposed relatively inward in the radial direction of the holding hole 31 and an outer end 402 disposed relatively outward in the radial direction.

複数の油溝４０の内端４０１は、ラック軸１０の軸線の方向に関して均等に互いに離隔して配置されている。複数の油溝４０の外端４０２も、ラック軸１０の軸線の方向に関して均等に互いに離隔して配置されている。内端４０１は、径方向内方に向けて閉塞されている。外端４０２は、径方向外方に向けて閉塞されている。保持孔３１の径方向に関する油溝４０の内端４０１および外端４０２が閉じられることにより、重力により潤滑剤３９が下方に落下することを防止でき、その結果、潤滑不良の発生を防止できる。 Inner ends 401 of the plurality of oil grooves 40 are equally spaced from each other in the direction of the axis of the rack shaft 10. The outer ends 402 of the plurality of oil grooves 40 are also equally spaced from each other with respect to the direction of the axis of the rack shaft 10. The inner end 401 is closed inward in the radial direction. The outer end 402 is closed outward in the radial direction. By closing the inner end 401 and the outer end 402 of the oil groove 40 in the radial direction of the holding hole 31, it is possible to prevent the lubricant 39 from falling downward due to gravity, and as a result, it is possible to prevent the occurrence of poor lubrication.

外端４０２は、ラック軸支持部材３４の後面３４３の外周縁部に、保持孔３１の深さ方向Ｚ３に沿って対向している。複数の油溝４０の外端４０２の外接円の直径は、ラック軸支持部材３４の後面３４３の外径と等しい値か、この値よりも大きい値とされるのが、好ましい。これにより、環状の領域３４７，３５６が互いに局部的に接触するときに潤滑剤３９を確実に供給できる。なお、複数の油溝４０の外端４０２の外接円の直径がラック軸支持部材３４の後面３４３の外径と等しい値よりも小さい場合も考えられる。 The outer end 402 faces the outer peripheral edge portion of the rear surface 343 of the rack shaft support member 34 along the depth direction Z3 of the holding hole 31. The diameter of the circumscribed circle of the outer ends 402 of the plurality of oil grooves 40 is preferably set to a value equal to or greater than the outer diameter of the rear surface 343 of the rack shaft support member 34. Thus, the lubricant 39 can be reliably supplied when the annular regions 347 and 356 are in local contact with each other. It is also conceivable that the diameter of the circumscribed circle of the outer ends 402 of the plurality of oil grooves 40 is smaller than the same value as the outer diameter of the rear surface 343 of the rack shaft support member 34.

油溝４０は、封止部材３５の前面３５２の環状の領域３５６から、径方向内方に連続して延び出している。内端４０１が、付勢部材３６の端部３６１に、保持孔３１の深さ方向Ｚ３に沿って対向している。例えば、複数の油溝４０の内端４０１の内接円の直径が、付勢部材３６のコイルの外径と等しい値よりも小さくされており、例えば、付勢部材３６のコイルの内径と等しくされている。 The oil groove 40 continuously extends radially inward from the annular region 356 of the front surface 352 of the sealing member 35. The inner end 401 faces the end portion 361 of the biasing member 36 along the depth direction Z3 of the holding hole 31. For example, the diameter of the inscribed circle of the inner ends 401 of the plurality of oil grooves 40 is smaller than the value equal to the outer diameter of the coil of the biasing member 36, for example, equal to the inner diameter of the coil of the biasing member 36. Has been.

油溝４０の内端４０１に収容された潤滑剤３９により、付勢部材３６の端部３６１と封止部材３５との間を潤滑できる。その結果、付勢部材３６の端部３６１が封止部材３５に対してスムーズに摺動できる。従って、ラック軸支持部材３４の後面３４３と封止部材３５の前面３５２との相対摺動をスムーズにするのに寄与する。なお、油溝４０がラック軸支持部材３４に形成されている場合にも、付勢部材３６の端部３６１とラック軸支持部材３４との間を潤滑できるので、同様の効果が得られる。 The lubricant 39 accommodated in the inner end 401 of the oil groove 40 can lubricate between the end 361 of the biasing member 36 and the sealing member 35. As a result, the end 361 of the urging member 36 can slide smoothly with respect to the sealing member 35. Therefore, it contributes to smooth relative sliding between the rear surface 343 of the rack shaft support member 34 and the front surface 352 of the sealing member 35. Even when the oil groove 40 is formed in the rack shaft support member 34, since the gap between the end 361 of the biasing member 36 and the rack shaft support member 34 can be lubricated, the same effect can be obtained.

さらに、図５、図６に示すように、油溝４０の断面深さ方向で外周に向かって外径方向に傾斜しているため、潤滑剤の通り道が狭まりとなるため、潤滑剤収容凹部としての油溝４０に収容された潤滑剤３９により、油膜圧力が発生してラック軸支持部材３４および封止部材３５の環状の領域３４６，３５６間を潤滑できるので、この間の摩擦を低減することができる。例えば、環状の領域３４６，３５６間の摩擦係数を、ひいては摩擦力を小さくすることができる。 Further, as shown in FIGS. 5 and 6, since the oil groove 40 is inclined in the outer diameter direction toward the outer periphery in the cross-sectional depth direction, the passage of the lubricant is narrowed. Since the oil film pressure is generated by the lubricant 39 accommodated in the oil groove 40 and the annular regions 346 and 356 of the rack shaft support member 34 and the sealing member 35 can be lubricated, friction between them can be reduced. it can. For example, the coefficient of friction between the annular regions 346 and 356, and thus the frictional force, can be reduced.

従って、仮に、ラック９とピニオン８との噛み合い反力が大きいときに、保持孔３１内で傾いたラック軸支持部材３４の後面３４３の外縁の一部Ｐ１と封止部材３５の前面３５２の一部Ｐ２とが局部的に接触することがあるとしても、傾いた状態のラック軸支持部材３４の後面３４３の外縁の一部Ｐ１と封止部材３５の前面３５２との摺動抵抗が小さくなる。このため、傾いた状態のラック軸支持部材３４が、大きな力を受けなくても、封止部材３５に沿って、傾きを戻すようにスムーズに動くことになる。ひいては、ラック軸支持部材３４と封止部材３５との衝突による異音も生じ難くなる。 Therefore, if the reaction force between the rack 9 and the pinion 8 is large, a part P1 of the outer edge of the rear surface 343 of the rack shaft support member 34 inclined in the holding hole 31 and the front surface 352 of the sealing member 35 Even if the portion P2 may come into local contact, the sliding resistance between the part P1 of the outer edge of the rear surface 343 of the rack shaft support member 34 in the tilted state and the front surface 352 of the sealing member 35 is reduced. For this reason, even if the rack shaft support member 34 in the inclined state does not receive a large force, it moves smoothly along the sealing member 35 so as to return the inclination. As a result, abnormal noise due to the collision between the rack shaft support member 34 and the sealing member 35 is less likely to occur.

なお、後述するように、潤滑剤収容凹部は、ラック軸支持部材３４の後面３４３および封止部材３５の前面３５２の少なくとも一方の環状の領域３４６，３５６に配置されていればよい。本実施形態では、潤滑剤収容凹部が封止部材３５の前面３５２のみに形成された複数の油溝４０からなる場合に則して説明する。図３および図４を参照して、ラック軸支持部材３４の後面３４３と封止部材３５の前面３５２との環状の領域３４６，３５６においては、油溝４０以外の部分が、互いに当接可能な当接可能部として機能する。これら当接可能部同士が互いに当接することにより、ラック軸支持部材３４の移動量が規制される。 In addition, as will be described later, the lubricant accommodating recesses may be disposed in at least one annular region 346, 356 of the rear surface 343 of the rack shaft support member 34 and the front surface 352 of the sealing member 35. In the present embodiment, a description will be given in accordance with a case where the lubricant containing recess is composed of a plurality of oil grooves 40 formed only on the front surface 352 of the sealing member 35. With reference to FIGS. 3 and 4, in the annular regions 346 and 356 between the rear surface 343 of the rack shaft support member 34 and the front surface 352 of the sealing member 35, portions other than the oil groove 40 can contact each other. It functions as a contactable part. The amount of movement of the rack shaft support member 34 is restricted by the contactable portions contacting each other.

図７に本発明の第２実施形態をしめしているが、本発明では、油溝６０をラック軸１０の軸線の方向に平行に設置している。さらに図８に示すようにラック支持部材３４の同心円上に外径側に行くほど深さ方向に浅くして、径方向に移動時に潤滑剤の流路を狭くする構造である。 FIG. 7 shows a second embodiment of the present invention. In the present invention, the oil groove 60 is installed in parallel to the direction of the axis of the rack shaft 10. Further, as shown in FIG. 8, the structure is such that the outer diameter side of the rack support member 34 is concentric with the rack support member 34, and the flow path of the lubricant is narrowed when moving in the radial direction.

本実施形態では、封止部材３５の前面３５２がラック軸支持部材３４の後面６５２に当接した状態では、潤滑剤３９は、環状の領域３４６，３５６全体に押し拡げられるとともに、油溝６０内に保持されている。従って、潤滑不良が生じる虞はない。さらにラック支持部材３４の同心円上に外径側に行くほど深さ方向に浅くして、径方向に移動時に潤滑剤の流路を狭くなり、潤滑剤の油膜圧力が発生する。これに対して、従来は、封止部材の前面の環状の領域の全面とラック軸支持部材の後面の環状の領域の全面とがそれぞれ平面により形成されていたので、互いに当接したときに、潤滑剤が押し出され、潤滑不良が生じる場合があった。 In the present embodiment, in a state where the front surface 352 of the sealing member 35 is in contact with the rear surface 652 of the rack shaft support member 34, the lubricant 39 is pushed and spread over the entire annular regions 346 and 356, and in the oil groove 60. Is held in. Therefore, there is no risk of poor lubrication. Further, the outer diameter side of the rack support member 34 becomes shallower toward the outer diameter side, and the depth of the lubricant becomes narrower when moving in the radial direction, and the oil film pressure of the lubricant is generated. On the other hand, conventionally, since the entire surface of the annular region on the front surface of the sealing member and the entire surface of the annular region on the rear surface of the rack shaft support member are each formed by a flat surface, In some cases, the lubricant was pushed out, resulting in poor lubrication.

このように本実施形態のラックアンドピニオン式ステリング装置１では、潤滑剤収容凹部としての油溝６０により、ラック軸支持装置２８における異音の発生を防止でき、且つ操舵部材２の操作に伴いラック軸１０をスムーズに動作させることができる。ひいては、操舵するときの追従性を高め、ハンドル戻りをスムーズにでき、操舵感を向上させることができる。 As described above, in the rack and pinion type stelling device 1 of the present embodiment, the oil groove 60 as the lubricant accommodating recess can prevent the rack shaft support device 28 from generating abnormal noise, and the rack is accompanied by the operation of the steering member 2. The shaft 10 can be operated smoothly. As a result, it is possible to improve the following ability when steering, to smoothly return the steering wheel, and to improve the steering feeling.

７…ピニオン軸、１０，１０Ｄ…ラック軸、２８，２８Ａ，２８Ｂ，２８Ｃ，２８Ｄ…ラック軸支持装置、３０…ハウジング、３１…保持孔、３４，３４Ａ，３４Ｃ，３４Ｄ…ラック軸支持部材、３５…封止部材、３６…付勢部材、３９…潤滑剤、４０，６０…油溝（潤滑剤収容凹部）、３１１…入口、３４３，３４３Ａ，３４３Ｃ…（ラック軸支持部材の）後面、３４６，３４６Ａ，３４６Ｃ…（ラック軸支持部材の後面の）環状の領域、３５２…（封止部材の）前面、３５２Ａ…第１面、３５２Ｂ…第２面、３５６…（封止部材の前面の）環状の領域、３６１…（付勢部材の）端部、４０１…油溝の内端、Ｚ３…深さ方向。 7 ... pinion shaft, 10, 10D ... rack shaft, 28, 28A, 28B, 28C, 28D ... rack shaft support device, 30 ... housing, 31 ... holding hole, 34, 34A, 34C, 34D ... rack shaft support member, 35 ... Sealing member, 36 ... Biasing member, 39 ... Lubricant, 40, 60 ... Oil groove (lubricant containing recess), 311 ... Inlet, 343, 343A, 343C ... Rear surface (of rack shaft support member), 346 346A, 346C ... annular region (on the rear surface of the rack shaft support member), 352 ... front surface (of the sealing member), 352A ... first surface, 352B ... second surface, 356 ... (on the front surface of the sealing member) 361 ... end (of the urging member), 401 ... inner end of the oil groove, Z3 ... depth direction.

Claims

軸方向に進退するラック軸と、このラック軸に噛合するピニオン軸と、前記ラック軸を軸方向に進退可能に支持するとともに前記ピニオン軸を回転可能に支持し、前記ラック軸を挟んで前記ピニオン軸と反対側に保持孔を形成したハウジングと、前記保持穴に摺動可能に収容され前記ラック軸を摺動可能に支持するラック軸支持部材と、前記保持孔の閉止する位置に設けられた封止部材と、前記封止部材および前記ラック軸支持部材間に介挿され、前記ラック軸支持部材を前記ラック軸側に付勢する付勢部材とを備えたラックアンドピニオン式ステアリング装置において、前記ラック軸支持部材および前記封止部材の互いに向かい合う端面の少なくとも一方に、前記ラック軸支持部材の中心軸を通る前記ラック軸と平行な線上に油溝の無い平らな第１面を設け、前記ラック軸支持部材の中心軸を通る前記ラック軸と直角な線上に平らな面の一部に油溝を形成した第２面を設けたことを特徴とするラックアンドピニオン式ステアリング装置。 A rack shaft that advances and retreats in the axial direction, a pinion shaft that meshes with the rack shaft, and supports the rack shaft so that it can advance and retreat in the axial direction, and supports the pinion shaft so that it can rotate, and the pinion sandwiches the rack shaft A housing formed with a holding hole on the opposite side of the shaft, a rack shaft support member slidably received in the holding hole and slidably supporting the rack shaft, and provided at a position where the holding hole is closed In a rack and pinion type steering apparatus comprising: a sealing member; and a biasing member that is interposed between the sealing member and the rack shaft support member and biases the rack shaft support member toward the rack shaft. A flat surface having no oil groove on a line parallel to the rack shaft passing through the central axis of the rack shaft support member on at least one of the end surfaces of the rack shaft support member and the sealing member facing each other. And a second surface having an oil groove formed in a part of a flat surface on a line perpendicular to the rack shaft passing through the central axis of the rack shaft support member. Pinion type steering device.

前記油溝は、前記ラック軸の軸線と直角方向に延び、前記ラック軸の軸線方向に複数並行に配置されていることを特徴とする請求項１に記載のラックアンドピニオン式ステアリング装置。 The rack-and-pinion type steering device according to claim 1, wherein the oil groove extends in a direction perpendicular to the axis of the rack shaft, and a plurality of the oil grooves are arranged in parallel in the axial direction of the rack shaft.

前記油溝は、前記ラック軸支持部材の外径側に向かって溝深さが浅くなる形状を有することを特徴とする請求項２に記載のラックアンドピニオン式ステアリング装置。 The rack and pinion type steering device according to claim 2, wherein the oil groove has a shape in which a groove depth becomes shallower toward an outer diameter side of the rack shaft support member.