JPS5929567A - Steering gear for vehicle - Google Patents

Steering gear for vehicle

Info

Publication number
JPS5929567A
JPS5929567A JP14015682A JP14015682A JPS5929567A JP S5929567 A JPS5929567 A JP S5929567A JP 14015682 A JP14015682 A JP 14015682A JP 14015682 A JP14015682 A JP 14015682A JP S5929567 A JPS5929567 A JP S5929567A
Authority
JP
Japan
Prior art keywords
tooth
rack
sector gear
neutral position
teeth
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP14015682A
Other languages
Japanese (ja)
Inventor
Ryutaro Abe
安部　隆太郎
Satoshi Sudo
数藤　聰
Katsuyuki Takeuchi
克之 竹内
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyoda Koki KK
Original Assignee
Toyoda Koki KK
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyoda Koki KK filed Critical Toyoda Koki KK
Priority to JP14015682A priority Critical patent/JPS5929567A/en
Publication of JPS5929567A publication Critical patent/JPS5929567A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D3/00—Steering gears
    • B62D3/02—Steering gears mechanical
    • B62D3/04—Steering gears mechanical of worm type
    • B62D3/06—Steering gears mechanical of worm type with screw and nut
    • B62D3/08—Steering gears mechanical of worm type with screw and nut using intermediate balls or the like

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)

Abstract

PURPOSE:To make appropriate the torque on a steering wheel at its neutral position and stabilize steering, by a method wherein tooth profile of a central rack tooth is expanded in the direction of tooth width in proximity to the parts located on the axis of symmetry of basic rack for whole depth of the tooth, and is shrinked at the top and the root of the tooth. CONSTITUTION:When a ball nut 22 is located at its neutral position, the central rack tooth 24 of a rack part 23 engaged with a sector gear 31 so formed that the tooth surface Wa is expanded, beyond the tooth surface W of a reference tooth profile indicated by an imaginary line slanted at a predetermined pressure angle theta, in the direction of the tooth width at parts located on the axis of symmetry of basic rack for whole depth of the tooth 24 and is shrinked at the tip and the root of the tooth 24. When the ball nut 22 is located at its neutral position, the central rack tooth 24 does not interface with the roots of the sector teeth 32, 32 at its tip, and the rack teeth 24-26 are engaged with the tooth surfaces V of the sector teeth 32, 32 at its expanded tooth surfaces Wa over the entire length thereof, so that the preload becomes maximum.

Description

【発明の詳細な説明】 本発明は、車輌用舵取装置、特に操舵軸の操作に応答し
て軸方向に作動するポールナツトを内蔵したケーシング
の軸線に直交して出力軸を配設し、該出力軸と一体的に
設けたセクタギヤを前記ボールナンドに形成したラック
部に噛合させてなるポールナツト型舵取装置に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION The present invention provides a steering device for a vehicle, in particular an output shaft disposed perpendicular to the axis of a casing containing a pole nut that operates in the axial direction in response to operation of a steering shaft. The present invention relates to a pole nut type steering device in which a sector gear provided integrally with an output shaft is engaged with a rack portion formed in the ball nut.

従来、この種型式の動力舵取装置は、例えば第１図及び
第２図にて示したように、操舵軸１１の回転に応じて作
動するサーボ弁１２によって圧力流体の給排が制御され
るパワーシリンダ２０と、該パワーシリンダ２０の軸線
に直交して軸支した出力軸（クロスシャフト）３０を備
えていて、パワーシリンダ２０のピストン２１と一体的
に形成したポールナツト２２のランク部２３に出力軸３
０の一端に一体的に設けたセクタギヤ３１を噛合させて
、ピストン２１の軸動により出力軸３０が回転するよう
に構成されている。かかる構成において、セクタギヤ３
１は基準ラックとして創成したポールナツト２２のラッ
ク部２３と噛合する転位歯車の形態にあって、このセク
タギヤ３１とラノり部２３の噛合線Ｘは第３図に示した
ように出力軸３０の中心軸線３０ａに対して角度δだけ
１頃斜している。また、ラック部２３がその中立位置に
あるとき、セクタギヤ３１の大径端側Ａにおいては、第
４図に示したように、ランク部２３の中央ラック歯２４
がセクタギヤ３１を構成している一対のセクタ歯３２．
３２間の歯溝内に位置していて両、セクタ歯３２．３２
の各歯面Ｖ、■が前後のラック歯２５，２６の各歯面Ｗ
、Ｗにそれぞれ所定の圧力角θにて噛合している。この
場合、この種のセクタギヤ３１においてはその小径、Ｍ
旧…＋ｌＢから大径端側Ａに向けてのテーパ角付だけ転
位量が増加しているため、中央ラック歯２４の歯先が両
セクタ歯３’２．３２の歯元から離れている。一方、セ
クタギヤ３１の小径端側Ｂにおいては、第５図に示した
ように、中央ラック歯２４の歯先が両セクタ歯３２．３
２の歯元に噛合しかつ両セクタ歯３２．３２の各歯面Ｖ
、Ｖが前後のラック歯２，５゜２６の各歯面Ｗ、Ｗに所
定の圧力角θにて噛合している。このため、ピストン２
１が中立位置にあ置にあるときセクタギヤ３１０大１番
端側ＡでばＰｌ、Ｐ２の２点で噛合するので中央ランク
歯２４に作用するプリロードが低下した状態にあるが、
ピストン２１の軸動によってラック部２３が図示左方に
移動するとき、セクタギヤ３１の大径端側Ａにては噛合
点Ｐ３でも噛合するようになり、その結果ランク部２３
とセクタギヤ３１の噛合点が二点から三点に移行する。Conventionally, in this type of power steering device, the supply and discharge of pressure fluid is controlled by a servo valve 12 that operates in accordance with the rotation of a steering shaft 11, as shown in FIGS. 1 and 2, for example. It is equipped with a power cylinder 20 and an output shaft (cross shaft) 30 supported perpendicularly to the axis of the power cylinder 20, and outputs to the rank part 23 of a pole nut 22 formed integrally with the piston 21 of the power cylinder 20. Axis 3
A sector gear 31 integrally provided at one end of the piston 21 is engaged with the output shaft 30 so that the output shaft 30 is rotated by the axial movement of the piston 21. In such a configuration, sector gear 3
1 is in the form of a shifted gear that meshes with the rack portion 23 of the pole nut 22 created as a reference rack, and the meshing line It is inclined by an angle δ of about 1 with respect to the axis 30a. Further, when the rack portion 23 is in its neutral position, the center rack tooth 24 of the rank portion 23 is located at the large diameter end side A of the sector gear 31, as shown in FIG.
A pair of sector teeth 32 . constitute the sector gear 31 .
Located in the tooth groove between 32 and 32, both sector teeth 32.32
Each tooth surface V, ■ represents each tooth surface W of the front and rear rack teeth 25, 26
, W at a predetermined pressure angle θ. In this case, in this type of sector gear 31, its small diameter, M
Since the amount of dislocation increases by the taper angle from the old... +1B toward the large diameter end A, the tooth tip of the central rack tooth 24 is separated from the root of both sector teeth 3'2.32. On the other hand, on the small diameter end side B of the sector gear 31, as shown in FIG.
2 and each tooth surface V of both sector teeth 32 and 32.
, V mesh with the respective tooth surfaces W, W of the front and rear rack teeth 2, 5° 26 at a predetermined pressure angle θ. For this reason, piston 2
1 is in the neutral position, the large end A of the sector gear 310 meshes at two points, Pl and P2, so the preload acting on the center rank tooth 24 is in a reduced state.
When the rack portion 23 moves to the left in the drawing due to the axial movement of the piston 21, the large diameter end side A of the sector gear 31 comes to mesh with the meshing point P3, and as a result, the rank portion 23
The meshing points of the sector gear 31 shift from two points to three points.

この噛合点の変化はランク部２３が在方へ移動するとき
も同じである。This change in the engagement point is the same when the rank portion 23 moves in the same direction.

このような噛合点の変化によって第８図＜ａ＞にて示し
たように操舵軸１工に連゛結した操舵ハンドルに作用す
るプリロードが操舵角の変化に伴って増大し、いわゆる
ハンドルトルクの二重現象が生じ、これが直進走行時に
おけるハンドルのふらつき原因の一つとなっている。Due to such changes in the engagement point, the preload acting on the steering handle connected to the steering shaft 1 increases as the steering angle changes, as shown in Fig. 8 <a>, and the so-called steering torque increases. A double phenomenon occurs, and this is one of the causes of the steering wheel wobbling when driving straight.

また、上記した問題に対処するため、ランク部２３０基
準ピンチ線とセクタギヤ３１の軸心間の間隔を縮小して
セクタギヤ３１の大径端側Ａにおける中央ラック歯２４
の歯先を中立位置にて両セクタ歯３２．３２の歯元に噛
合させた場合には、その噛合による干渉のため中央ラッ
ク歯２４の歯先が早期に摩耗し、中立状態におけるプリ
ロードがなくなってしまい、操舵者に違和感を与える。In addition, in order to deal with the above-mentioned problem, the distance between the rank part 230 reference pinch line and the axis of the sector gear 31 is reduced, and the central rack tooth 24 at the large diameter end side A of the sector gear 31 is
When the tooth tips of the central rack teeth 24 are meshed with the roots of both sector teeth 32 and 32 in the neutral position, the teeth tips of the central rack teeth 24 will wear out early due to the interference caused by the meshing, and the preload in the neutral state will be lost. This gives the driver a sense of discomfort.

本発明は、上記したハンドルトルクの二重現象をなくし
てハンドルの中立位置におけるプリロードを適確に得よ
うとするもので、以下にその実施態様を第６図及び第７
図を参照して説明する。The present invention aims to eliminate the double phenomenon of handle torque described above and obtain an appropriate preload at the neutral position of the handle.
This will be explained with reference to the figures.

第６図は、第１図に示したようにボールナツト２２がそ
の中立位置にあるときセクタギヤ３１に噛合するラック
部２３の中央ランク歯２４に本発明を適用した例を示し
ている。この適用例において、中央ランク歯２４は、そ
の歯面ｗａ　＋　Ｗ　ａを所定の圧力角θで伸斜する仮
想線にて示した基準歯形の歯面ｗ１ｗよりも同ラック歯
２４の金歯たけの基準ピッチ線ａ上に対応する部分にて
歯厚方向に膨出させるとともに歯先と歯元にてくぼませ
て形成したことに構成上の特徴がある。FIG. 6 shows an example in which the present invention is applied to the center rank tooth 24 of the rack portion 23 that meshes with the sector gear 31 when the ball nut 22 is in its neutral position as shown in FIG. In this application example, the center rank tooth 24 has a tooth surface wa + W a that is higher than the tooth surface w1w of the standard tooth profile, which is indicated by an imaginary line extending at a predetermined pressure angle θ. The structural feature is that the portion corresponding to the pitch line a is bulged in the tooth thickness direction, and the tooth tip and root are recessed.

かかる構成により、ボールナツト２２がその中立位置に
あるとき、中央ラック歯２４はその歯先にて両セクタ歯
３２．３２の歯元と干渉することなくその膨出歯面Ｗａ
、Ｗａにてセクタ歯３２゜３２の各歯面■と噛合し、そ
の結果セクタギヤ３１の両セクタ歯３２’、３２の全長
にわたってラック歯２４，２５．２６が四点にて噛合し
、この噛合状態にて操舵ハンドルに作用するプリロード
が最大（！：　する〔第８図（ｂ）参照〕。また、ボー
ルナツト２２の軸動によってラック部２３がその中立位
置から図示左方又は右方に所定量移動するときには、中
央ラック歯２４の膨出歯面Ｗａ、Ｗａと両セクタ歯３２
．３２の各歯面■との噛合点が基準ピッチ線上がら各セ
クタ歯３２の歯先又は歯元に向けて移動し、一方ランク
部２３が所定量移動すると中央ラック歯２４の前後に位
置するラック歯２５あるいは２６とセクタギヤ３１との
噛合が終了する。すなわち、かがる作動時にはラック部
２３とセクタギヤ３１の噛合点が四点から三点に移行す
るため、第８図（ｂ）にて示したように、操舵ハンドル
に作用するプリロードが操舵角の増大に伴って減少し、
従来問題となっていたハンドルトルクの二重現象を確実
になくすことができる。With this configuration, when the ball nut 22 is in its neutral position, the center rack tooth 24 does not interfere with the tooth root of both sector teeth 32, 32 at its tooth tip, and the bulging tooth surface Wa.
, Wa mesh with each tooth surface () of the sector teeth 32, 32, and as a result, the rack teeth 24, 25, 26 mesh at four points over the entire length of both sector teeth 32', 32 of the sector gear 31, and this meshing occurs. In this state, the preload acting on the steering wheel is at its maximum (!) [see Fig. 8 (b)]. Also, due to the axial movement of the ball nut 22, the rack portion 23 moves from its neutral position to the left or right in the figure by a predetermined amount. When moving, the bulging tooth surfaces Wa, Wa of the central rack tooth 24 and both sector teeth 32
．． The meshing point with each tooth surface (■) of 32 moves up the reference pitch line toward the tip or root of each sector tooth 32, and on the other hand, when the rank portion 23 moves a predetermined amount, the rack is located before and behind the center rack tooth 24. The meshing between the tooth 25 or 26 and the sector gear 31 is completed. That is, during the overturning operation, the meshing points between the rack part 23 and the sector gear 31 shift from four to three, so the preload acting on the steering wheel changes as the steering angle changes, as shown in FIG. 8(b). decreases as it increases,
The dual phenomenon of steering wheel torque, which has been a problem in the past, can be reliably eliminated.

また、上記作動時にはセクタギヤ３１と頻繁に噛合する
中央ラック歯２４がその歯先にてセクタ歯３２の歯元に
噛合しないため、ランク部２３の耐摩耗性を向上させる
ことができる。さらに、中央ラック歯２４の歯厚は第７
図に示したようにセクタギヤ３１の大ｔ’ｌｒ　ｍＭ側
Ａから小径端側Ｂに向って角度αだけテーパ状に小さく
したことも構成の特徴で、ある。この膨出歯面Ｗａ、Ｗ
ａの長手方向の１項斜角αはセクタギヤ３１の転位量を
考慮して定めたもので、この傾斜角αを変化させること
によって、ラック部２３とセクタギヤ３１の噛合線δの
傾斜角を変化させることができる。Further, during the above operation, the center rack tooth 24, which frequently meshes with the sector gear 31, does not mesh with the root of the sector tooth 32 at its tooth tip, so that the wear resistance of the rank portion 23 can be improved. Furthermore, the tooth thickness of the central rack tooth 24 is 7th.
As shown in the figure, another feature of the configuration is that the sector gear 31 is tapered by an angle α from the large t'lr mm side A toward the small diameter end B. These bulging tooth surfaces Wa, W
The first-term bevel angle α in the longitudinal direction a is determined by taking into consideration the amount of displacement of the sector gear 31, and by changing this inclination angle α, the inclination angle of the meshing line δ between the rack portion 23 and the sector gear 31 can be changed. can be done.

以上詳述したとおり、本発明は、ボールナツト型舵取装
置において、ボールナンドが中立位置にあるときセクタ
ギヤに噛合するランク部の中央ラック歯の歯形形状を、
所定の圧力角で傾斜する基準歯形の歯面よりもその全歯
たけの基準ピンチ線上に対応する部分の近傍にて歯厚方
向に膨出しその歯先と歯元にてくぼんだ形状にしたこと
にその構成上の特徴があり、これによって中立位置にお
けるハンドルトルクを適確に高めて操舵ハンドルのふら
つき現象をなくすことができるとともにラック部の耐摩
耗性を向上させることができる。さらに本発明は、中央
ラック歯の歯厚をセクタギヤの大径端側から小径端側に
向ってテーパ状に形成したものであるため、このテーパ
領斜角を任意に設定することで噛合線の傾斜角を変える
ことができる利点を有する。As detailed above, the present invention provides a ball nut type steering device in which the tooth profile shape of the central rack tooth of the rank portion that meshes with the sector gear when the ball nut is in the neutral position is
The tooth surface of the standard tooth profile inclined at a predetermined pressure angle is bulged in the tooth thickness direction near the part corresponding to the standard pinch line of the entire tooth depth, and the tooth tip and root are concave. Due to this structural feature, it is possible to appropriately increase the steering wheel torque at the neutral position, eliminate the wobbling phenomenon of the steering wheel, and improve the wear resistance of the rack portion. Furthermore, in the present invention, since the tooth thickness of the center rack teeth is tapered from the large diameter end to the small diameter end of the sector gear, the meshing line can be adjusted by arbitrarily setting the taper oblique angle. It has the advantage of being able to change the angle of inclination.

なお、本発明の実施にあたっては、上述した中央ラック
歯の歯面を直線的に膨出させてもよく、その形状によっ
ては中立位置のプリロードをフラットにすることもでき
る〔第８図（ｂ）参照〕。In carrying out the present invention, the tooth surface of the above-mentioned central rack tooth may be linearly bulged, and depending on its shape, the preload at the neutral position may be made flat [Fig. 8(b)] reference〕.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の適用対象であるボールナンド型動力舵
取装置の側断面図、第２図は同舵取装置の横断面図、第
３図は第２図の部分拡大図、第４図は第３図に示したセ
クタギヤの大径端側におけるランク部との噛合状態を示
す説明図、第５図は同セクタギヤの小径端側におけるラ
ンク部との噛合状態を示す説明図、第６図は本発明を適
用したラック部の中央ラック歯のセクタギヤとの噛合状
態を示す説明図、第７図は第６図に示した中央ラック歯
のテーパ角を示す説明図、第８図（ａ）は従来装置にお
ける操舵角とハンドルトルクの関係を示すグラフ、同図
（ｂ）は本発明装置における操舵角とハンドルトルクの
関係を示すグラフである。 符号の説明 ２２・・・ボールナツト、２３・・・ラック部、２４・
・・中央ラック歯、３１・・・セクタギヤ、３２・・・
セクタ歯、Ｗａ・・・膨出歯面。 出願人　豊田工機株式会社 代理人　弁理士　長　谷　照　− （ほか１名） 第３図 ＪＵａ 第６図 第７図 第８図 （ａ） （ｂ） ＴＭ　いンドルトルク）FIG. 1 is a side sectional view of a Bornand type power steering device to which the present invention is applied, FIG. 2 is a cross-sectional view of the same steering device, FIG. 3 is a partially enlarged view of FIG. 2, and FIG. The figure is an explanatory view showing the state of meshing with the rank portion on the large diameter end side of the sector gear shown in FIG. 3, FIG. 5 is an explanatory view showing the state of meshing with the rank portion on the small diameter end side of the sector gear, and FIG. The figures are explanatory diagrams showing the meshing state of the center rack teeth with the sector gear of the rack section to which the present invention is applied, FIG. 7 is an explanatory diagram showing the taper angle of the central rack teeth shown in FIG. 6, and FIG. ) is a graph showing the relationship between the steering angle and the steering wheel torque in the conventional device, and FIG. 3(b) is a graph showing the relationship between the steering angle and the steering wheel torque in the device of the present invention. Explanation of symbols 22...Ball nut, 23...Rack part, 24...
...Central rack tooth, 31...Sector gear, 32...
Sector tooth, Wa... bulging tooth surface. Applicant Toyoda Machine Tool Co., Ltd. Agent Patent Attorney Teru Hase - (1 other person) Figure 3 JUa Figure 6 Figure 7 Figure 8 (a) (b) TM Indle Torque)

Claims (2)

【特許請求の範囲】[Claims] （１）操舵軸の操作に応答して軸方向に作動するポール
ナツトを内蔵したケーシングの軸線に直交して出力軸を
配設し、該出力軸と一体的に設けたセクタギヤを前記ポ
ールナツトに形成したランク部に噛合させてなる舵取装
置において、前記ポールナツトが中立位置にあるとき前
記セクタギヤに噛合する前記ランク部の中央ラック歯の
歯形形状を、所定の圧力角で傾斜する基準歯形の歯面よ
りもその全歯たけの基準ピンチ線上に対応する部分の近
傍にて歯厚方向に膨出しその歯先と歯元にてくぼんだ形
状にしたことを特徴とする車輌用舵取装置。(1) An output shaft is disposed perpendicular to the axis of a casing containing a pole nut that operates in the axial direction in response to the operation of the steering shaft, and a sector gear provided integrally with the output shaft is formed on the pole nut. In a steering device that meshes with a rank part, the tooth profile of the central rack tooth of the rank part that meshes with the sector gear when the pole nut is in a neutral position is determined from the tooth surface of a reference tooth profile that is inclined at a predetermined pressure angle. A steering device for a vehicle, characterized in that the steering device has a shape that bulges in the tooth thickness direction near a portion corresponding to a reference pinch line of the total tooth depth and is concave at the tooth tip and tooth base. （２）前記中央ランク歯の歯厚を前記セクタギヤの大径
端側から小径端側に向かって次第にテーバ状に小さくし
たことを特徴とする特許請求の範囲第１項記載の車輛用
舵取装置。(2) The steering device for a vehicle according to claim 1, wherein the tooth thickness of the central rank tooth is gradually tapered from the large-diameter end to the small-diameter end of the sector gear. .
JP14015682A 1982-08-12 1982-08-12 Steering gear for vehicle Pending JPS5929567A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14015682A JPS5929567A (en) 1982-08-12 1982-08-12 Steering gear for vehicle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14015682A JPS5929567A (en) 1982-08-12 1982-08-12 Steering gear for vehicle

Publications (1)

Publication Number Publication Date
JPS5929567A true JPS5929567A (en) 1984-02-16

Family

ID=15262167

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14015682A Pending JPS5929567A (en) 1982-08-12 1982-08-12 Steering gear for vehicle

Country Status (1)

Country Link
JP (1) JPS5929567A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61102380A (en) * 1984-10-22 1986-05-21 Jidosha Kiki Co Ltd Steering gear unit of constant gear ratio
JPH0238379U (en) * 1988-09-07 1990-03-14

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61102380A (en) * 1984-10-22 1986-05-21 Jidosha Kiki Co Ltd Steering gear unit of constant gear ratio
JPH0238379U (en) * 1988-09-07 1990-03-14

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