JPH0728050Y2 - Power steering device - Google Patents
Power steering deviceInfo
- Publication number
- JPH0728050Y2 JPH0728050Y2 JP1985116442U JP11644285U JPH0728050Y2 JP H0728050 Y2 JPH0728050 Y2 JP H0728050Y2 JP 1985116442 U JP1985116442 U JP 1985116442U JP 11644285 U JP11644285 U JP 11644285U JP H0728050 Y2 JPH0728050 Y2 JP H0728050Y2
- Authority
- JP
- Japan
- Prior art keywords
- oil passage
- pressure
- control valve
- oil
- valve
- 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.)
- Expired - Lifetime
Links
Description
【考案の詳細な説明】 (産業上の利用分野) 本考案は自動車のパワーステアリング装置に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a power steering device for an automobile.
(従来の技術) 従来,ステアリングホイールに連結された入力軸と,同
入力軸の回転を出力軸に伝えるトーシヨンバーと,同出
力軸に連結されたパワーシリンダと,上記入力軸と上記
出力軸との回転角度差に応じて上記パワーシリンダへの
油路を切換える油路切換弁と,オイルポンプから吐出さ
れる作動油を上記油路切換弁を介して上記パワーシリン
ダへ供給する高圧油路と,同高圧油路の途中に設けられ
た主オリフイスと,上記パワーシリンダから上記油路切
換弁を介してオイルタンクへ作動油を戻す低圧油路と,
上記入力軸と上記出力軸との間で規制力を付与して同各
軸の回転角度差を制限する反力ピストンと,上記高圧油
路の途中から上記反力ピストンへ延びた制御油路と,上
記反力ピストンへ延びた上記制御油路の油圧を所定の最
高圧以下に制御する圧力制御バルブと,同圧力制御バル
ブと上記反力ピストンとの間の上記制御油路の途中から
分かれた一対の並列油路と,同各並列油路の一方に設け
られた第2のオリフイスと,同各並列油路の何れかを選
択してそこを流れる作動油の流量を車速に応じた流量に
制御する流量制御バルブと,同流量制御バルブの下流側
油路に作動油の流量に対応したパイロット圧を発生させ
る第1のオリフイスと,同パイロット圧を上記圧力制御
バルブに供給するパイロット油路と,上記主オリフイス
の上流側高圧油路と下流側高圧油路とをバイパスするバ
イパス通路と,上記圧力制御バルブ下流側の油圧が所定
の最低圧以下になったときだけに同バイパス通路を閉じ
て制御油路全体の油圧を増大させるチエンジ・オーバー
・バルブとを具えている自動車のパワーステアリング装
置は,公知である(必要ならば特願昭58-86598号明細書
(特開昭59-213564号公報)を参照されたい)。(Prior Art) Conventionally, an input shaft connected to a steering wheel, a torsion bar for transmitting the rotation of the input shaft to an output shaft, a power cylinder connected to the output shaft, the input shaft and the output shaft An oil passage switching valve that switches the oil passage to the power cylinder according to the rotation angle difference, and a high-pressure oil passage that supplies the working oil discharged from the oil pump to the power cylinder via the oil passage switching valve. A main orifice provided in the middle of the high-pressure oil passage, a low-pressure oil passage for returning hydraulic oil from the power cylinder to the oil tank via the oil passage switching valve,
A reaction force piston that applies a restriction force between the input shaft and the output shaft to limit the rotational angle difference between the shafts, and a control oil passage that extends from the middle of the high pressure oil passage to the reaction piston. , A pressure control valve for controlling the hydraulic pressure of the control oil passage extending to the reaction force piston to a predetermined maximum pressure or less, and the control oil passage between the pressure control valve and the reaction force piston. A pair of parallel oil passages, a second orifice provided on one of the parallel oil passages, and one of the parallel oil passages are selected and the flow rate of the hydraulic oil flowing therethrough is set to a flow rate according to the vehicle speed. A flow control valve to be controlled, a first orifice for generating a pilot pressure corresponding to the flow rate of hydraulic oil in a downstream oil passage of the flow control valve, and a pilot oil passage for supplying the pilot pressure to the pressure control valve. , High pressure oil passage upstream of the main orifice A bypass passage that bypasses the high-pressure oil passage on the downstream side and a chimney that increases the oil pressure on the entire control oil passage by closing the bypass passage only when the oil pressure on the downstream side of the pressure control valve falls below a predetermined minimum pressure. An automobile power steering device having an over valve is known (see Japanese Patent Application No. 58-86598 (Japanese Patent Laid-Open No. 59-213564) if necessary).
(考案が解決しようとする問題点) 前記自動車のパワーステアリング装置は,反力ピストン
へ延びた制御油路の油圧を所定の最高圧以下に制御する
圧力制御バルブ,並列油路の何れかを選択してそこを流
れる作動油の流量を車速に応じた流量に制御する流量制
御バルブ,圧力制御バルブ下流側の油圧が所定の最低圧
以下になったときだけに同バイパス通路を閉じて制御油
路全体の油圧を増大させるチエンジ・オーバー・バルブ
等の高精度の部品を多く必要として,製作コストを高め
ていた。それに対して本考案は,高精度の部品が圧力制
御バルブとソレノイドだけになるので,製作コストを低
減できるものである。(Problems to be solved by the invention) The power steering device of the automobile selects one of a pressure control valve and a parallel oil passage for controlling the hydraulic pressure of the control oil passage extending to the reaction piston below a predetermined maximum pressure. The flow control valve that controls the flow rate of the hydraulic oil flowing therethrough to a flow rate according to the vehicle speed, the pressure control valve The bypass passage is closed only when the hydraulic pressure on the downstream side falls below a specified minimum pressure. Many high-precision parts such as changeover valves that increase the overall hydraulic pressure were required, which increased the manufacturing cost. On the other hand, the present invention can reduce the manufacturing cost because the only high-precision parts are the pressure control valve and the solenoid.
しかしながら、本考案のように両端に面したバルブハウ
ジング内にチャンバーが形成された圧力制御バルブを使
用するとき、各チャンバーを互いに連通するドレン油路
や圧力制御バルブの外周に形成され圧力制御バルブの変
位に応じて作動油の流入量を制御する制御溝と圧力制御
バルブの外周面に形成され反力ピストンに作用する油圧
に応じた差圧を発生し圧力制御バルブを変位させる力を
発生する差圧部とを互いに連通する油路をバルブハイジ
ング内に設けた場合には、(I)多くの孔をハルブハウ
ジング内に穿設しなければならず,バリ取りも必要で,
工数が増加する。(II)また作動油に混入している空気
がバルブハウジングの外面に開口されるドレン油路の開
口部をシールするメクラボール直下のドレン油路内等に
溜まって,制御上に不都合を生じるという問題がある。However, when using a pressure control valve in which chambers are formed in the valve housing facing both ends as in the present invention, the pressure control valve formed on the outer periphery of the drain oil passage or the pressure control valve that communicates each chamber with each other is used. The difference between the control groove that controls the inflow of hydraulic oil according to the displacement and the pressure difference that is generated on the outer peripheral surface of the pressure control valve and that generates the pressure difference that corresponds to the hydraulic pressure acting on the reaction force piston and that displaces the pressure control valve. When an oil passage communicating with the pressure section is provided in the valve housing, (I) many holes must be bored in the hull housing, and deburring is necessary.
The man-hour increases. (II) In addition, the air mixed in the hydraulic oil accumulates in the drain oil passage directly below the blind ball that seals the opening of the drain oil passage that is opened to the outer surface of the valve housing, which causes a problem in control. There's a problem.
(問題点を解決するための手段) 本考案は前記の問題点に対処するもので,ステアリング
ホイールに連結された入力軸と,同入力軸の回転を出力
軸に伝えるトーシヨンバーと,同出力軸に連結されたパ
ワーシリンダと,上記入力軸と上記出力軸との回転角度
差に応じて上記パワーシリンダへの油路を切換える油路
切換弁と,オイルポンプから吐出される作動油を上記油
路切換弁を介して上記パワーシリンダへ供給する高圧油
路と,上記パワーシリンダから上記油路切換弁を介して
オイルタンクへ作動油を戻す低圧油路と,上記入力軸と
上記出力軸との間で規制力を付与して同各軸の回転角度
差を制限する反力ピストンと,上記高圧油路の途中から
上記反力ピストンへ延びた制御油路と、両端に面したバ
ルブハウジング内にチャンバーが形成され上記反力ピス
トンへ延びた上記制御油路に介装され上記反力ピストン
に作用する油圧の上昇と共に圧力制御用ばねの付勢力に
抗して変位し上記油圧を所定の最高圧以下に制御する圧
力制御バルブと,同圧力制御バルブと上記反力ピストン
との間の上記制御油路を上記低圧油路に連通させるリタ
ーン側オリフィスと,車速に応じて変わり且つ車速毎に
略一定の軸力を発生するプランジャを介して上記ばねに
対抗して上記圧力制御バルブを作動させるソレノイドと
を具えているパワーステアリング装置において,上記各
チャンバーの一方を上記低圧油路に連通し、同各チャン
バーを互いに連通するドレン油路を上記圧力制御バルブ
内に設けると共に、上記圧力制御バルブの外周面に形成
され上記圧力制御バルブの変位に応じて作動油の流入量
を制御する環状の制御溝と上記圧力制御バルブの外周面
に形成され上記反力ピストンに作用する油圧に応じた差
圧を発生し上記制御バルブを変位させる力を発生する差
圧部とを互いに連通する油路を上記ドレン油路と連通し
ないように上記圧力制御バルブ内に設けたことを特徴と
するパワーステアリング装置である。(Means for Solving Problems) The present invention addresses the above-mentioned problems, and includes an input shaft connected to a steering wheel, a torsion bar for transmitting the rotation of the input shaft to the output shaft, and an output shaft. A connected power cylinder, an oil passage switching valve that switches an oil passage to the power cylinder according to a rotation angle difference between the input shaft and the output shaft, and operating oil discharged from an oil pump to change the oil passage. Between the high pressure oil passage for supplying the power cylinder via the valve, the low pressure oil passage for returning the working oil from the power cylinder to the oil tank through the oil passage switching valve, and the input shaft and the output shaft. A reaction force piston that applies a restriction force to limit the rotational angle difference between the shafts, a control oil passage that extends from the middle of the high pressure oil passage to the reaction force piston, and a chamber inside the valve housing facing both ends are provided. Formed The control oil passage interposed in the control oil passage extending to the reaction force piston is displaced against the biasing force of the pressure control spring as the hydraulic pressure acting on the reaction force piston rises, and the hydraulic pressure is controlled to be equal to or lower than a predetermined maximum pressure. Pressure control valve, a return-side orifice that connects the control oil passage between the pressure control valve and the reaction piston to the low-pressure oil passage, and an axial force that changes according to the vehicle speed and is substantially constant for each vehicle speed. In a power steering device comprising a solenoid for actuating the pressure control valve against the spring via a plunger that generates a pressure, one of the chambers is connected to the low pressure oil passage, and the chambers are connected to each other. A communicating drain oil passage is provided in the pressure control valve, and the inflow amount of the hydraulic oil is formed on the outer peripheral surface of the pressure control valve according to the displacement of the pressure control valve. The annular control groove for controlling and the differential pressure portion formed on the outer peripheral surface of the pressure control valve for generating a pressure difference corresponding to the hydraulic pressure acting on the reaction force piston and generating a force for displacing the control valve are communicated with each other. Is provided in the pressure control valve so as not to communicate the oil passage with the drain oil passage.
(作用) 本考案は、入力軸と出力軸との間で規制力を付与して各
軸の回転速度差を制限する反力ピストンの作動が、高圧
油路の途中から反力ピストンへ延びた制御油路を介して
供給される油圧に応じて制御されステアリングホイール
の操舵力が制御されるものである。(Operation) In the present invention, the operation of the reaction force piston that applies the restriction force between the input shaft and the output shaft to limit the rotational speed difference between the shafts extends from the middle of the high pressure oil passage to the reaction force piston. The steering force of the steering wheel is controlled in accordance with the hydraulic pressure supplied through the control oil passage.
そして、圧力制御バルブと反力ピストンとの間の制御油
路に低圧油路に連通させるリターン側オリフィスを設け
ていることから、反力ピストンに供給される油圧は、圧
力制御バルブと反力ピストンとの間の制御油路に供給さ
れる作動油の流量により変化する。また、反力ピストン
へ延びた制御油路に反力ピストンに作用する油圧を圧力
制御用ばねの付勢力に抗して所定の最高圧以下に制御す
る圧力制御バルブが介装されているため、圧力制御バル
ブと反力ピストンとの間の制御油路に供給される作動油
の流量が増大して反力ピストンに作用する油圧が上昇す
ると、圧力制御バルブが反力制御用ばねの付勢力を抗し
て変位して反力ピストンに作用する油圧を所定の最高圧
以下に制御されることとなり、ステアリングホイールの
操舵力が必要以上に増大することを防止することができ
るものである。Further, since the return-side orifice that communicates with the low-pressure oil passage is provided in the control oil passage between the pressure control valve and the reaction piston, the hydraulic pressure supplied to the reaction piston is equal to the pressure control valve and the reaction piston. It changes depending on the flow rate of the hydraulic oil supplied to the control oil passage between and. Further, a control oil passage extending to the reaction force piston is provided with a pressure control valve that controls the hydraulic pressure acting on the reaction force piston to a predetermined maximum pressure or less against the biasing force of the pressure control spring. When the flow rate of the hydraulic oil supplied to the control oil passage between the pressure control valve and the reaction force piston increases and the hydraulic pressure acting on the reaction force piston rises, the pressure control valve applies the urging force of the reaction force control spring. The hydraulic pressure acting on the reaction force piston due to the displacement is controlled to a predetermined maximum pressure or less, and it is possible to prevent the steering force of the steering wheel from increasing more than necessary.
更に、車速に応じて変わり且つ車速毎に略一定の軸力を
発生するプランジャを介して圧力制御用ばねに対抗して
圧力制御バルブを変位させるソレノイドを設けているの
で、圧力制御バルブに付与される付勢力が車速に応じて
変化することとなり、このことから、上記の所定の最高
圧が車速に応じて変化して、ステアリングホイールの操
舵力が車速に応じて制御されるものである。Further, since a solenoid that displaces the pressure control valve against the pressure control spring is provided via a plunger that changes according to the vehicle speed and generates a substantially constant axial force for each vehicle speed, it is provided to the pressure control valve. The urging force of the steering wheel changes according to the vehicle speed. From this, the predetermined maximum pressure changes according to the vehicle speed, and the steering force of the steering wheel is controlled according to the vehicle speed.
このように、油圧の上昇に伴い圧力制御用ばねに付勢力
を抗して変位する圧力制御バルブと、圧力制御用ばねに
対抗して圧力制御バルブを変位させるソレノイドとを使
用することにより、比較的簡素な構成で確実にステアリ
ングホイールの操舵力を車速に応じて制御できるもので
ある。Thus, by using the pressure control valve that displaces the pressure control spring against the biasing force as the hydraulic pressure increases and the solenoid that displaces the pressure control valve against the pressure control spring, The steering force of the steering wheel can be reliably controlled according to the vehicle speed with a simple structure.
更に、圧力制御バルブの両端に面しバルブハウジング内
に形成される各チャンバーの一方を上記低圧油路に連通
し、同各チャンバーを互いに連通するドレン油路を圧力
制御バルブ内に設けると共に、圧力制御バルブの外周面
に形成され圧力制御バルブの変位に応じて作動油の流入
量を制御する環状の制御溝と圧力制御バルブの外周面に
形成され反力ピストンに作用する油圧に応じた差圧を発
生し上記制御バルブを変位させる力を発生する差圧部と
を互いに連通する油路をドレン油路と連通しないように
圧力制御バルブ内に設けたことにより、バルブハウジン
グ内に穿設する油路が少なくなり、工数が低減し、しか
も作動油に購入している空気の溜まりを形成しないの
で、同空気がメクラボール直下の油路等に溜まって生じ
ていた制御上の不都合も解消されるものである。Further, one of the chambers formed in the valve housing facing both ends of the pressure control valve is connected to the low pressure oil passage, and a drain oil passage for connecting the chambers to each other is provided in the pressure control valve. An annular control groove formed on the outer peripheral surface of the control valve to control the inflow of hydraulic oil according to the displacement of the pressure control valve, and a differential pressure corresponding to the hydraulic pressure acting on the reaction force piston formed on the outer peripheral surface of the pressure control valve. Is provided in the pressure control valve so as not to communicate with the drain oil passage, the oil passage communicating with the pressure difference generating portion that generates the force for displacing the control valve. The number of passages is reduced, the number of man-hours is reduced, and the pool of air purchased for hydraulic oil is not formed. But also it is eliminated.
(実施例) 次に本考案のパワーステアリング装置を第1図乃至第15
図に示す各実施例により説明する。まず第1図によりそ
の概略を説明すると,(1)がエンジン(図示せず)に
より駆動されるオイルポンプで,同オイルポンプ(1)
は,流量が一定(7l/min程度)の,また吐出圧が可変
(0kg/cm2〜80kg/cm2)のオイルポンプである。また
(2)が四方向油路切換弁(ロータリバルブ),(2a)
が同油路切換弁(2)を操作するステアリングホイー
ル,(3)が操舵用パワーシリンダ,(4)がオイルタ
ンク,(5)が複数個の反力ピストン,(6)が同各反
力ピストン(5)の背後に形成したチヤンバー,(7a)
が上記オイルポンプ(1)から上記油路切換弁(2)へ
延びた高圧油路,(8a)が同油路切換弁(2)から上記
オイルタンク(4)へ延びた低圧油路,(9a)(10a)
が上記油路切換弁(2)から上記パワーシリンダ(3)
へ延びた油路,(7b)(7c)(7d)(7e)が上記高圧油
路(7a)から分岐した制御油路で,同制御油路(7b)
(7c)(7d)(7e)が上記各反力ピストン(5)背後の
チヤンバー(6)へ延びている。また(11)が上記制御
油路(7b)(7c)の間に介装した圧力制御バルブで,同
圧力制御バルブ(11)が上記反力ピストン(5)背後の
チヤンバー(6)へ延びた上記制御油路(7c)(7d)
(7e)の油圧を所定の最高圧以下に制御するようになっ
ている。また(12)がソレノイド,(14)が車速セン
サ,(15)が制御装置(コントローラ),(16)がイグ
ニシヨンスイツチ,(17)がイグニシヨンコイル,(1
8)が上記制御装置(15)から上記ソレノイド(12)へ
延びた配線で,上記車速センサ(14)が車速を検出し,
そのとき得られるパルス信号(車速に応じたパルス信
号)が制御装置(15)へ送られ,同制御装置(15)が同
パルス信号に対応した電流(電流値が零になる所定の高
速時から電流値が最大になる停車時までの車速に対応し
た電流)が配線(18)を介してソレノイド(12)の電磁
コイル(図示せず)へ送られる。このとき,同ソレノイ
ド(12)のプランジヤには,車速に応じて変わり且つ車
速毎に略一定の軸力が発生し,この軸力が上記圧力制御
バルブ(11)に伝えられて,同圧力制御バルブ(11)が
圧力制御用ばね(19)(以下、ばね(19)と称する。)
に抗して変位するようなっている。また(13)が上記圧
力制御バルブ(11)と上記反力ピストン(5)との間の
上記制御油路(7c)(7d)(7e)を低圧油路(8b)に連
通させて同低圧油路(8b)上流側の同制御油路(7c)
(7d)(7e)に制御油圧を発生させるリターン側オリフ
イス,(7c1)が圧力制御バルブ(11)に設けた後記受
圧部(43)に発生するパイロット圧である。(Embodiment) Next, a power steering device of the present invention will be described with reference to FIGS.
Description will be made with reference to each embodiment shown in the drawings. First, referring to FIG. 1, an outline thereof will be described. (1) is an oil pump driven by an engine (not shown).
Is an oil pump with a constant flow rate (about 7 l / min) and variable discharge pressure (0 kg / cm 2 to 80 kg / cm 2 ). (2) is a four-way oil passage switching valve (rotary valve), (2a)
Is a steering wheel for operating the oil passage switching valve (2), (3) is a power cylinder for steering, (4) is an oil tank, (5) is a plurality of reaction force pistons, and (6) is each reaction force. Chamber formed behind the piston (5), (7a)
Is a high-pressure oil passage extending from the oil pump (1) to the oil passage switching valve (2), and (8a) is a low-pressure oil passage extending from the oil passage switching valve (2) to the oil tank (4), ( 9a) (10a)
From the oil passage switching valve (2) to the power cylinder (3)
(7b) (7c) (7d) (7e) is a control oil passage branched from the above high pressure oil passage (7a), and the control oil passage (7b)
(7c), (7d) and (7e) extend to the chamber (6) behind each reaction force piston (5). Further, (11) is a pressure control valve interposed between the control oil passages (7b) and (7c), and the pressure control valve (11) extends to a chamber (6) behind the reaction force piston (5). Control oil passage (7c) (7d)
The hydraulic pressure of (7e) is controlled below a predetermined maximum pressure. Further, (12) is a solenoid, (14) is a vehicle speed sensor, (15) is a controller (controller), (16) is an ignition switch, (17) is an ignition coil, (1
8) is a wiring extending from the control device (15) to the solenoid (12), and the vehicle speed sensor (14) detects the vehicle speed,
The pulse signal (pulse signal corresponding to the vehicle speed) obtained at that time is sent to the control device (15), and the control device (15) outputs a current corresponding to the pulse signal (from a predetermined high speed when the current value becomes zero). A current corresponding to the vehicle speed until the vehicle stops, when the current value becomes maximum, is sent to the electromagnetic coil (not shown) of the solenoid (12) via the wiring (18). At this time, in the plunger of the solenoid (12), an axial force that changes according to the vehicle speed and is approximately constant for each vehicle speed is generated, and this axial force is transmitted to the pressure control valve (11) to control the pressure. The valve (11) includes a pressure control spring (19) (hereinafter referred to as a spring (19)).
It is designed to be displaced against. Further, (13) communicates the control oil passages (7c) (7d) (7e) between the pressure control valve (11) and the reaction force piston (5) with the low pressure oil passage (8b) to bring the same low pressure. Oil passage (8b) Control oil passage (7c) on the upstream side
(7d) return side orifice for generating a control hydraulic pressure (7e), a pilot pressure generated in the later pressure receiving portion (7c 1) is provided in the pressure control valve (11) (43).
次に前記油路切換弁(2)を第2図乃至第5図により具
体的に説明すると,ハウジングが鋳鉄等の硬金属製バル
ブハウジング(20a)と同質材製ピニオンハウジング(2
0b)とに分割され,同ピニオンハウジング(20b)がス
テアリングギヤ&リンケージ(図示せず)に一体的に取
付けられ,上記バルブハウジング(20a)が同ピニオン
ハウジング(20b)に後述するように着脱自在に取付け
られている。また(21)がステアリングホイール(第1
図の(2a)参照)により操作される入力軸,(23)がニ
ードルベアリング(36)により上記バルブハウジング
(20a)内に回転可能に支持されたシリンダブロツク,
(22)が上記入力軸(21)内に挿入されたトーシヨンバ
ーで,同トーシヨンバー(22)の上部が上記入力軸(2
1)の上部に圧入ピン(22a)を介して固定され,同トー
シヨンバー(22)の下部が上記シリンダブロツク(23)
の内孔にスプライン係合されている。また(21a)が上
記入力軸(21)の下部外周面等間隔位置に設けた複数個
(本実施例では4個)の縦溝で,上記シリンダブロツク
(23)には,同各縦溝(21a)に対向して複数個(本実
施例では4個)のシリンダが横向きに設けられ,同各シ
リンダに反力ピストン(5)が嵌挿され,同各反力ピス
トン(5)の背後に相当するシリンダブロツク(23)と
バルブハウジング(20a)との間には,環状のチヤンバ
ー(6)が形成されている。また(23a)が上記シリン
ダブロツク(23)に一体のピニオンで,同ピニオン(23
a)が上記ピニオンハウジング(20b)内に垂下状態に突
出している。また(24a)が同ピニオン(23a)に噛合し
たラツク(出力軸),(24)が同ラツク(24a)の背後
に位置するラツクサポート,(26)が上記ピニオンハウ
ジング(20b)に固定したキヤツプ,(25)が同キヤツ
プ(26)と上記ラツクサポート(24)との間に介装した
ばね,(27)が上記バルブハウジング(20a)と上記入
力軸(21)との間に介装した油路切換弁(2)のバルブ
ボデイで,同バルブボデイ(27)もバルブハウジング
(20a)と同様に鋳鉄等の硬金属により作られており,
同バルブボデイ(27)がバルブハウジング(20a)の孔
に直接摺動可能に嵌挿されている。また(23b)が同バ
ルブボデイ(27)の下端部と上記シリンダブロツク(2
3)の上端部とを回転方向に係合するピン,(27a)(27
b)(27c)が上記バルブボデイ(27)の外周面に設けた
環状油路で,ステアリングホイール(2a)が中立位置に
あるときには,第1図の高圧油路(7a)がバルブボデイ
(27)の環状油路(27a)→入力軸(21)とバルブボデ
イ(27)に形成された油路(図示せず)→チヤンバー
(29)→低圧油路(8a)に連通して,オイルポンプ
(1)からの作動油が高圧油路(7a)→環状油路(27
a)→入力軸(21)とバルブボデイ(27)に形成された
油路→チヤンバー(29)→低圧油路(8a)→オイルタン
ク(4)→オイルポンプ(1)に循環するようになって
いる。またステアリングホイール(2a)を右に切って,
入力軸(21)をバルブボデイ(27)に対して右方向に相
対回転すると,高圧油路(7a)がバルブボデイ(27)の
環状油路(27a)(27b)を介してパワーシリンダ(3)
の油路(9a)に,パワーシリンダ(3)の油路(10a)
がバルブボデイ(27)の環状油路(27c)とチヤンバー
(29)とを介して低圧油路(8a)に,それぞれ連通し
て,オイルポンプ(1)からの作動油が高圧油路(7a)
→環状油路(27a)→油路(9a)→パワーシリンダ
(3)の左室へ送られる一方,パワーシリンダ(3)の
右室の作動油が油路(10a)→環状油路(27c)→チヤン
バー(29)→入力軸(21)を横方向に貫通した油路(4
7)→低圧油路(8a)→オイルタンク(4)へ戻され,
パワーシリンダ(3)のピストンロツドが右へ移動し
て,右方向への操舵が行われるようになっている。また
ステアリングホイール(2a)を左に切って,入力軸(2
1)をバルブボデイ(27)に対して左方向に相対回転す
ると,高圧油路(7a)がバルブボデイ(27)の環状油路
(27a)(27b)を介してパワーシリンダ(3)の油路
(10a)に,パワーシリンダ(3)の油路(9a)がバル
ブボデイ(27)の環状油路(27b)とチヤンバー(29)
とを介して低圧油路(8a)に,それぞれ連通して,オイ
ルポンプ(1)からの作動油が高圧油路(7a)→環状油
路(27c)→油路(10a)→パワーシリンダ(3)の右室
へ送られる一方,パワーシリンダ(3)の左室の作動油
が油路(9a)→環状油路(27b)→チヤンバー(29)→
入力軸(21)を横方向に貫通した油路(47)→低圧油路
(8a)→オイルタンク(4)へ戻され,パワーシリンダ
(3)のピストンロツドが左へ移動して,左方向への操
舵が行われるようになっている。また(30)が0リン
グ,(31)(35)がオイルシール,(32)(38)がボー
ルベアリング,(33)(34)がシール,(37)がブツシ
ユ,(39)がナツト,(40)がキヤツプ,第5図の(20
c)(20c)が上記ハルブハウジング(20a)と上記ピニ
オンハウジング(20b)とを着脱自在に固定するボルト
で,ハルブハウジング(20a)がピニオンハウジング(2
0b)から分離した状態ときに,圧力制御バルブ(11)等
に対する入出力特性のチエツクが行われ,またハルブハ
ウジング(20a)側の圧力制御バルブ(11)等に対する
入出力特性のチエツクが終わったときに,バルブハウジ
ング(20a)をピニオンハウジング(20b)上にセツト
し,同バルブハウジング(20a)側のピニオン(23a)を
ピニオンハウジング(20b)内に突出して,ピニオンハ
ウジング(20b)側のラツク(24a)に噛み合わせ,ナツ
ト(39)を螺合し,キヤツプ(40)を締め付け,さらに
ボルト(20c)を締め付けて,本装置の全体を組み付け
る。また上記組み付け後の点検時等に,バルブハウジン
グ(20a)をピニオンハウジング(20b)から取り外して
も,入力軸(21)とバルブハウジング(20a)との間に
オイルシール(31)があり,シリンダブロツク(23)と
バルブハウジング(20a)との間にオイルシール(35)
があり,キヤツプ(49)とバルブハウジング(20a)と
の間及びキヤツプ(49)とばね支持部材(50)との間に
シール用0リング(53)があり,さらにソレノイド(1
2)とバルブハウジング(20a)との間にシール用0リン
グ(58)があるので,作動油の漏洩がない。Next, the oil passage switching valve (2) will be described in detail with reference to FIGS. 2 to 5. The housing is a hard metal valve housing (20a) made of cast iron or the like and a pinion housing (2) made of the same material.
0b), the pinion housing (20b) is integrally attached to a steering gear & linkage (not shown), and the valve housing (20a) is detachable from the pinion housing (20b) as described later. Installed on. In addition, (21) is the steering wheel (first
A cylinder block in which an input shaft (23) is rotatably supported in the valve housing (20a) by a needle bearing (36);
(22) is a torsion bar inserted into the input shaft (21), and the upper part of the torsion bar (22) is the input shaft (2
It is fixed to the upper part of 1) via a press-fit pin (22a), and the lower part of the same torsion bar (22) is above the cylinder block (23).
Is spline-engaged with the inner hole. Further, (21a) is a plurality of (4 in this embodiment) vertical grooves provided at equal intervals on the lower outer peripheral surface of the input shaft (21), and the vertical grooves (4) in the cylinder block (23). 21a) is provided with a plurality of (four in this embodiment) cylinders in a lateral direction, and the reaction force pistons (5) are fitted and inserted in the respective cylinders, and behind each reaction force piston (5). An annular chamber (6) is formed between the corresponding cylinder block (23) and the valve housing (20a). Further, (23a) is a pinion integrated with the cylinder block (23), and the pinion (23a)
a) projects downward in the pinion housing (20b). Further, (24a) is a rack (output shaft) meshing with the pinion (23a), (24) is a rack support located behind the rack (24a), and (26) is a cap fixed to the pinion housing (20b). , (25) is a spring interposed between the cap (26) and the rack support (24), and (27) is interposed between the valve housing (20a) and the input shaft (21). The valve body of the oil passage switching valve (2), which is also made of hard metal such as cast iron as the valve housing (20a).
The valve body (27) is slidably inserted into the hole of the valve housing (20a). Also, (23b) is the lower end of the valve body (27) and the cylinder block (2
Pins (27a) (27) that engage the upper end of 3) in the rotational direction.
b) (27c) is an annular oil passage provided on the outer peripheral surface of the valve body (27), and when the steering wheel (2a) is in the neutral position, the high pressure oil passage (7a) in FIG. The oil pump (1) communicates with the annular oil passage (27a) → the oil passage (not shown) formed in the input shaft (21) and the valve body (27) → the chamber (29) → the low pressure oil passage (8a). Hydraulic oil from the high pressure oil passage (7a) → annular oil passage (27
a) → Oil passage formed in the input shaft (21) and valve body (27) → Chamber (29) → Low pressure oil passage (8a) → Oil tank (4) → Oil pump (1) There is. Turn the steering wheel (2a) to the right,
When the input shaft (21) is rotated to the right relative to the valve body (27), the high pressure oil passage (7a) passes through the annular oil passages (27a) (27b) of the valve body (27) and the power cylinder (3).
Oil passage (9a) of the power cylinder (3) oil passage (10a)
Communicate with the low pressure oil passage (8a) via the annular oil passage (27c) and the chamber (29) of the valve body (27), respectively, and the working oil from the oil pump (1) is supplied to the high pressure oil passage (7a).
→ Annular oil passage (27a) → Oil passage (9a) → While being sent to the left chamber of the power cylinder (3), hydraulic oil in the right chamber of the power cylinder (3) is oil passage (10a) → Annular oil passage (27c) ) → Chamber (29) → Oil passage (4
7) → low pressure oil passage (8a) → returned to the oil tank (4),
The piston rod of the power cylinder (3) moves to the right to steer to the right. Turn the steering wheel (2a) to the left and
When 1) is rotated leftward relative to the valve body (27), the high pressure oil passage (7a) passes through the annular oil passages (27a) (27b) of the valve body (27) and the oil passage (3) of the power cylinder (3). 10a), the oil passage (9a) of the power cylinder (3) is connected to the annular oil passage (27b) of the valve body (27) and the chamber (29).
The hydraulic oil from the oil pump (1) communicates with the low-pressure oil passage (8a) via and, respectively, and the high-pressure oil passage (7a) → annular oil passage (27c) → oil passage (10a) → power cylinder ( While being sent to the right chamber of 3), the hydraulic oil in the left chamber of the power cylinder (3) is oil passage (9a) → annular oil passage (27b) → chamber (29) →
The oil passage (47) laterally penetrating the input shaft (21) → the low pressure oil passage (8a) → is returned to the oil tank (4), the piston rod of the power cylinder (3) moves to the left, and to the left. The steering is done. In addition, (30) is an O-ring, (31) (35) is an oil seal, (32) (38) is a ball bearing, (33) (34) is a seal, (37) is a bush, (39) is a nut, ( 40 is the cap, (20 in Fig. 5
c) and (20c) are bolts that detachably fix the hull housing (20a) and the pinion housing (20b), and the hull housing (20a) is the pinion housing (2c).
Checking the input / output characteristics for the pressure control valve (11), etc. when separated from 0b), and ending the input / output characteristics for the pressure control valve (11), etc. on the hull housing (20a) side. At this time, the valve housing (20a) is set on the pinion housing (20b), the pinion (23a) on the valve housing (20a) side is projected into the pinion housing (20b), and the rack on the pinion housing (20b) side is projected. Engage with (24a), screw nut (39), tighten cap (40), and further tighten bolt (20c) to assemble this device as a whole. Even when the valve housing (20a) is removed from the pinion housing (20b) for inspection after the above-mentioned assembly, there is an oil seal (31) between the input shaft (21) and the valve housing (20a), Oil seal (35) between block (23) and valve housing (20a)
There is a sealing O-ring (53) between the cap (49) and the valve housing (20a) and between the cap (49) and the spring support member (50).
Since there is a sealing O-ring (58) between 2) and the valve housing (20a), there is no leakage of hydraulic oil.
次に前記圧力制御バルブ(11)を第2図乃至第5図によ
り具体的に説明すると,同圧力制御バルブ(11)は,前
記ハウジング(20a)(20b)と同様に耐摩耗性材例えば
鋳鉄等の硬金属で作られており,同圧力制御バルブ(1
1)がバルブハウジング(20a)の孔に直接摺動可能に嵌
挿されている。なお前記従来のパワーステアリング装置
では,ハウジングと各バルブのバルブボデイとを軟金属
材で作っているので,ハウジングと各バルブボデイとの
間に硬金属製スリーブを介装する必要があったが,本パ
ワーステアリング装置では,圧力制御バルブ(11)とバ
ルブハウジング(20a)とを硬金属で作っているので,
硬金属製スリーブを介装する必要がなくて,圧力制御バ
ルブ(11)をバルブハウジング(20a)の孔に直接摺動
可能に嵌挿している。この点は,前記油路切換弁(2)
のバルブボデイ(27)も同様である。また(41)が同圧
力制御バルブ(11)の上部外周面に設けた制御ランドの
環状制御溝,(41′)が同制御溝(41)よりも下方の同
圧力制御バルブ(11)の外周面に設けた環状バランス溝
で,同バランス溝(41′)が圧力制御バルブ(11)の右
側及び左側に設けた同一軸線上の制御油路(7b)(7b)
に連通し,これら左右の制御油路(7b)(7b)のうち,
左側(外側)の制御油路(7b)の端部がメクラボール
(59)によりシールされている。なお制御油路(7b)が
右側だけの場合,同制御油路(7b)の作動油が圧力制御
バルブ(11)を左方へ押し,圧力制御バルブ(11)のバ
ルブハウジング(20a)に対する摩擦抵抗が増大して,
圧力制御バルブ(11)が円滑に作動しなくなるが,本パ
ワーステアリング装置では,圧力制御バルブ(11)の左
右両側に制御油路(7b)(7b)があり,これらの制御油
路(7b)(7b)が圧力制御バルブ(11)の外周面に設け
た環状のバランス溝(41′)で連通されており,上記の
不都合を生じない。また(43)が同圧力制御バルブ(1
1)の下部外周面に設けた差圧部(環状溝)で,同差圧
部(43)の上部受圧面と下部受圧面とを比較すると,上
部受圧面の方が下部受圧面よりも受圧面積が大きい。そ
のため,ここに圧油が供給されると,圧力制御バルブ
(11)が上方へ押し上げられることになる。なお第1図
の(7c1)は上記受圧面積の差により生ずる上向きのパ
イロツト圧を示している。また(42)が同圧力制御バル
ブ(11)内を斜めに貫通した油路(インポート側オリフ
イス)で,同油路(42)が上記制御溝(41)と上記差圧
部(43)とを連通し,同差圧部(43)が第1,3,4,5図に
示す制御油路(7a)(7b)(7c)を介して反力ピストン
(5)背後のチヤンバー(6)に連通している。またシ
リンダブロツク(23)の内周面と入力軸(21)の下部外
周面との間には,油路(45)が形成され,同油路(45)
が入力軸(21)を横方向に貫通した油路(46)を介して
前記低圧油路(8b)側のチヤンバー(29)に連通してい
る。また第1図に示すリターン側オリフイス(13)がシ
リンダブロツク(23)内に設けられ,同リターン側オリ
フイス(13)と上記油路(45)との間に油路(44)が設
けられ,上記制御油路(7a)(7b)(7c)が同リターン
側オリフイス(13)→上記油路(44)(45)(46)→チ
ヤンバー(29)を介して低圧油路(8b)に連通してい
る。また(49)がキヤツプで,同キヤツプ(49)が上記
圧力制御バルブ(11)の上方のバルブハンジング(20
a)上部に設けたねじ部に螺合している。また(50)が
同ねじ部内に上下方向への移動を可能に嵌挿したばね支
持部材,(51)が上記開口部に螺合したアジヤストスク
リユウ,(19)(第1,3,4,5図参照)が上記ばね支持部
材(50)と圧力制御バルブ(11)との間に介装した圧力
制御バルブ用ばねで,同ばね(19)が圧力制御バルブ
(11)を下方に付勢している。また(53)が0リング,
(54)が上記ばね支持部材(50)の周りに形成されたチ
ヤンバー,(48)が上記バルブハンジング(20a)に設
けた油路で,上記チヤンバー(54)が上記油路(48)を
介して前記低圧油路(8b)に連通している。また(55)
が圧力制御バルブ(11)を上下方向に貫通したドレン油
路,(56)がソレノイド(12)内のプランジヤ(57)部
に連通したチヤンバーで,上記ドレン油路(55)が圧力
制御バルブ(11)の下方に形成した上記チヤンバー(5
6)と圧力制御バルブ(11)の上方に形成した上記上記
チヤンバー(54)とを連通している。前記リターン側オ
リフイス(13)は第13図に示すように制御溝(41)とド
レン油路(55)との間(または差圧部(43)とドレン油
路(55)との間)に設けてもよい。また上記各チヤンバ
ー(56)(54)を連通するドレン油路(55)を圧力制御
バルブ(11)に設けずに,バルブハウジング(20a)に
設けた場合には,圧力制御バルブ(11)と油路切換弁
(2)との間のバルブハウジング(20a)部分の上端面
から同バルブハウジング(20a)内に向かい縦方向のド
レン油路を穿設し,同縦方向のドレン油路の上部とチヤ
ンバー(54)とを横方向のドレン油路により,同縦方向
のドレン油路の下部とチヤンバー(56)とを横方向のド
レン油路により,それぞれ連通し,さらに同縦方向のド
レン油路の上端部をメクラボールによりシールする必要
があり,(I)多くの孔をバルブハウジング(20a)内
に穿設しなければならず,バリ取りも必要で,工数が増
加する。(II)また作動油に混入している空気が上記メ
クラボール直下の縦方向ドレン油路内上部に溜まって,
制御上に不都合を生じるが,本パワーズテアリング装置
では,上記2つのチヤンバー(56)(54)を圧力制御バ
ルブ(11)内を上下方向に貫通するドレン油路(55)に
より連通しており,上記の不都合を生じない。また第4
図の左上方に示すように,キヤツプ(49)の上端縁部の
一部がアジヤストスクリユウ(51)のねじ溝内に折り曲
げられて,ばね(19)のばね力を調整した後の同アジヤ
ストスクリユウ(51)が上記キヤツプ(49)に固定され
るようになっている。Next, the pressure control valve (11) will be described in detail with reference to FIGS. 2 to 5. The pressure control valve (11) is the same as the housings (20a) and (20b) and is made of wear resistant material such as cast iron. Made of hard metal such as
1) is directly slidably fitted in the hole of the valve housing (20a). In the above conventional power steering device, since the housing and the valve body of each valve are made of a soft metal material, it is necessary to interpose a hard metal sleeve between the housing and each valve body. In the steering device, the pressure control valve (11) and the valve housing (20a) are made of hard metal, so
The pressure control valve (11) is slidably fitted directly into the hole of the valve housing (20a) without the need for a hard metal sleeve. This point is that the oil passage switching valve (2)
The same applies to the valve body (27). Further, (41) is an annular control groove of a control land provided on the upper outer peripheral surface of the pressure control valve (11), and (41 ') is an outer periphery of the pressure control valve (11) below the control groove (41). Control oil passages (7b) (7b) on the same axis provided on the right and left sides of the pressure control valve (11), with annular balance grooves provided on the surface.
Of the left and right control oil passages (7b) (7b)
The end of the left (outer) control oil passage (7b) is sealed by a blind ball (59). When the control oil passage (7b) is on the right side only, the hydraulic oil in the control oil passage (7b) pushes the pressure control valve (11) to the left, causing friction of the pressure control valve (11) with respect to the valve housing (20a). Resistance increased,
Although the pressure control valve (11) does not operate smoothly, this power steering device has control oil passages (7b) and (7b) on the left and right sides of the pressure control valve (11). Since the (7b) is communicated with the annular balance groove (41 ') provided on the outer peripheral surface of the pressure control valve (11), the above inconvenience does not occur. In addition, (43) is the same pressure control valve (1
When comparing the upper pressure receiving surface and the lower pressure receiving surface of the same pressure difference portion (43) with the differential pressure portion (annular groove) provided on the lower outer peripheral surface of 1), the upper pressure receiving surface receives more pressure than the lower pressure receiving surface. The area is large. Therefore, when pressure oil is supplied here, the pressure control valve (11) is pushed upward. Note that (7c 1 ) in FIG. 1 shows the upward pilot pressure generated by the difference in the pressure receiving area. Further, (42) is an oil passage (import side orifice) that obliquely penetrates through the pressure control valve (11), and the oil passage (42) connects the control groove (41) and the differential pressure portion (43). In communication, the differential pressure section (43) is connected to the chamber (6) behind the reaction piston (5) via the control oil passages (7a) (7b) (7c) shown in Figs. It is in communication. An oil passage (45) is formed between the inner peripheral surface of the cylinder block (23) and the lower outer peripheral surface of the input shaft (21).
Is communicated with the chamber (29) on the side of the low pressure oil passage (8b) through an oil passage (46) that laterally penetrates the input shaft (21). The return-side orifice (13) shown in FIG. 1 is provided in the cylinder block (23), and the oil passage (44) is provided between the return-side orifice (13) and the oil passage (45). The control oil passages (7a) (7b) (7c) communicate with the low pressure oil passage (8b) via the return side orifice (13) → the oil passages (44) (45) (46) → the chamber (29). is doing. Further, (49) is a cap, and the cap (49) is a valve housing (20) above the pressure control valve (11).
a) It is screwed into the screw part provided on the upper part. Further, (50) is a spring support member fitted in the same threaded portion so as to be movable in the vertical direction, (51) is an adjust screw screwed into the opening, (19) (first, third, fourth, fifth, fifth) Is a pressure control valve spring interposed between the spring support member (50) and the pressure control valve (11). The spring (19) urges the pressure control valve (11) downward. ing. Also, (53) is the 0 ring,
(54) is a chamber formed around the spring support member (50), (48) is an oil passage provided in the valve housing (20a), and the chamber (54) forms the oil passage (48). Through the low pressure oil passage (8b). See also (55)
Is a drain oil passage vertically passing through the pressure control valve (11), (56) is a chamber communicating with the plunger (57) in the solenoid (12), and the drain oil passage (55) is a pressure control valve (55). 11) The lower chamber (5) formed below
6) communicates with the above-mentioned chamber (54) formed above the pressure control valve (11). As shown in FIG. 13, the return-side orifice (13) is placed between the control groove (41) and the drain oil passage (55) (or between the differential pressure section (43) and the drain oil passage (55)). It may be provided. Further, when the drain oil passage (55) communicating with the chambers (56) (54) is not provided in the pressure control valve (11) but in the valve housing (20a), the pressure control valve (11) and A vertical drain oil passage is bored from the upper end surface of the valve housing (20a) portion between the oil passage switching valve (2) and the upper part of the vertical drain oil passage. And the chamber (54) are connected by a horizontal drain oil passage, and the lower part of the vertical drain oil passage and the chamber (56) are connected by a horizontal drain oil passage. It is necessary to seal the upper end of the passage with a blind ball, and (I) many holes must be bored in the valve housing (20a), deburring is required, and the number of steps is increased. (II) Also, the air mixed in the hydraulic oil accumulates in the upper part of the vertical drain oil passage just below the blind ball,
In the power steering system, the two chambers (56) and (54) are connected to each other by a drain oil passage (55) that passes through the pressure control valve (11) in the vertical direction. The above inconvenience does not occur. Also the fourth
As shown in the upper left of the figure, part of the upper edge of the cap (49) is bent into the thread groove of the adjust screw (51) to adjust the spring force of the spring (19). The storage unit (51) is fixed to the cap (49).
次にソレノイド(12)を第3,4図により具体的に説明す
ると,同ソレノイド(12)の上部が上記圧力制御バルブ
(11)の直下の前記バルブハウジング(20a)にねじ込
まれている。なお(58)はシール用0リングである。ま
た同ソレノイド(12)内には,電磁コイル(図示せず)
とプランジヤ(57)とがあり,既に述べたように,車速
センサ(14)により得られるパルス信号(車速に応じた
パルス信号)が制御装置(15)へ送され,同制御装置
(15)が同パルス信号に対応した電流(電流値が零にな
る所定の高速時から電流値が最大になる停車時までの車
速に対応した電流)が配線(18)を介しソレノイド(1
2)の電磁コイルへ送られる。このとき,同ソレノイド
(12)のプランジヤ(57)には,車速に応じて変わり且
つ車速毎に略一定の軸力が発生し,この軸力が上記圧力
制御バルブ(11)に伝えられて,同圧力制御バルブ(1
1)がばね(19)に抗して作動するようなっている。第1
9図は,同プランジヤ(57)の軸力(g)とストローク
l(mm)との関係を示している。同第19図から明らかな
ように,ソレノイド(12)のプランジヤ(57)には,車
速(電流値)に応じて変わり且つ車速(電流値)毎に略
一定の軸力が発生する。同第19図の(a)から左側が通
常の使用範囲である。なお制御油路(7b)から制御溝
(41)→油路(インポート側オリフイス)(42)を経て
差圧部(43)に加わる油圧を(A),同差圧部(43)の
上部受圧面と下部受圧面との受圧面積差を(B),プラ
ンジヤ(57)の車速に応じて変わり且つ車速毎に略一定
の軸力を(C),ばね(19)の反力を(D)とすると,A
×B+C=Dの関係にあり,圧力制御バルブ(11)は,
上記関係式の成立する位置にバランスを保って保持され
ている。Next, the solenoid (12) will be described in detail with reference to FIGS. 3 and 4. The upper part of the solenoid (12) is screwed into the valve housing (20a) immediately below the pressure control valve (11). Note that (58) is a sealing O-ring. Further, an electromagnetic coil (not shown) is provided in the solenoid (12).
As described above, the pulse signal (pulse signal corresponding to the vehicle speed) obtained by the vehicle speed sensor (14) is sent to the control device (15), and the control device (15) The current corresponding to the pulse signal (current corresponding to the vehicle speed from a predetermined high speed when the current value becomes zero to the stop time when the current value becomes maximum) is passed through the wiring (18) to the solenoid (1
It is sent to the electromagnetic coil of 2). At this time, in the plunger (57) of the solenoid (12), an axial force that changes according to the vehicle speed and is approximately constant for each vehicle speed is generated, and this axial force is transmitted to the pressure control valve (11). Same pressure control valve (1
1) works against the spring (19). First
Figure 9 shows the relationship between the axial force (g) of the plunger (57) and the stroke l (mm). As is clear from FIG. 19, the plunger (57) of the solenoid (12) generates an axial force that varies depending on the vehicle speed (current value) and is substantially constant for each vehicle speed (current value). The left side of FIG. 19 (a) is the normal use range. The hydraulic pressure applied to the differential pressure section (43) from the control oil path (7b) through the control groove (41) to the oil path (import side orifice) (42) is received by the upper part of the differential pressure section (43). The pressure receiving area difference between the surface and the lower pressure receiving surface (B) changes according to the vehicle speed of the plunger (57), and a substantially constant axial force (C) for each vehicle speed, and the reaction force of the spring (19) (D). Then, A
There is a relationship of × B + C = D, and the pressure control valve (11) is
The balance is maintained at a position where the above relational expression holds.
次にインポートフイルタ(60)を第2,5〜8図により具
体的に説明する。オイルポンプ(1)から高圧油路(7
a)が延び,また同高圧油路(7a)から制御油路(7b)
〜(7e)が分かれている。同高圧油路(7a)は,通路の
径が太く,流量も多いため,仮に油路切換弁(2)の部
分にごみ等が侵入しても,同油路切換弁(2)が動かな
くなる虞れはないが,上記制御油路(7b)〜(7e)は,
通路の径が細く,流量も少なくて,ごみ等が侵入する
と,ごみ等が同制御油路(7b)〜(7e)の途中の狭隘な
部分,例えば圧力制御バルブ(11)の部分に溜り,同圧
力制御バルブ(11)がソレノイド(12)の力では動かな
くなる虞れがある。このため,高圧油路(7a)から制御
油路(7b)〜(7e)への分岐部に,インポートフイルタ
(60)を設けて,制御油路(7b)〜(7e)へのごみ等の
侵入を防止するようにしている。同インポートフイルタ
(60)は,配管(高圧油路(7a))と略同じ径の環状体
(61)(61)と同各環状体(61)を連結する複数本の連
結片(62)と同各環状体(61)と同各連結片(62)との
内面に添設した円筒状網(63)とにより構成されてい
る。同インポートフイルタ(60)は,配管(高圧油路
(7a)と略同じ径で,組み付けるときには,バルブハウ
ジング(20a)に設けた作動油の入口に嵌挿され,次い
で配管(高圧油路(7a))の先端部が同入口に嵌挿され
て,ナツト(64)が同入口にねじ込まれ,同配管の先端
部が同入口に固定されて,抜け出さないように且つ交換
可能に保持されている。この状態では,同インポートフ
イルタ(60)の円筒状網(63)が高圧油路(7a)と制御
油路(7b)〜(7e)との間に介在して,ごみ等の制御油
路(7b)〜(7e)への侵入を防止する。一方,円筒状網
(63)の両端部は開口しており、円筒状網(63)の内部
は,高圧油路(7a)の一部を形成することになる。なお
配管(高圧油路(7a))とインポートフイルタ(60)と
は直接接触していても,接触していなくてもよい。また
インポートフイルタ(60)を交換する場合には,ナツト
(64)を取り外して,配管(高圧油路(7a))を抜き出
せばよい。Next, the import filter (60) will be described in detail with reference to FIGS. From the oil pump (1) to the high pressure oil passage (7
a) extends, and the high-pressure oil passage (7a) to the control oil passage (7b)
~ (7e) is divided. Since the high-pressure oil passage (7a) has a large passage diameter and a large flow rate, even if dust or the like enters the oil passage switching valve (2), the oil passage switching valve (2) does not move. Although not afraid, the control oil passages (7b) to (7e) are
If the diameter of the passage is small, the flow rate is small, and dust enters, it collects in a narrow part in the middle of the control oil passages (7b) to (7e), such as the pressure control valve (11). The pressure control valve (11) may be stopped by the force of the solenoid (12). For this reason, an import filter (60) is provided at the branch portion from the high-pressure oil passage (7a) to the control oil passages (7b) to (7e) to prevent dust from entering the control oil passages (7b) to (7e). I try to prevent intrusion. The import filter (60) includes an annular body (61) (61) having substantially the same diameter as the pipe (high pressure oil passage (7a)) and a plurality of connecting pieces (62) connecting the annular bodies (61). It is composed of a cylindrical net (63) attached to the inner surfaces of the annular bodies (61) and the connecting pieces (62). The import filter (60) has substantially the same diameter as the pipe (high pressure oil passage (7a), and when assembled, is fitted into the hydraulic oil inlet provided in the valve housing (20a), and then the pipe (high pressure oil passage (7a) )) Is inserted into the same inlet, the nut (64) is screwed into the same inlet, and the tip of the pipe is fixed to the same inlet and held so as not to come out and replaceable. In this state, the cylindrical mesh (63) of the import filter (60) is interposed between the high-pressure oil passage (7a) and the control oil passages (7b) to (7e), and the control oil passages such as dust are (7b) to (7e) are prevented from entering.On the other hand, both ends of the cylindrical net (63) are open, and the inside of the cylindrical net (63) is part of the high pressure oil passage (7a). The piping (high pressure oil passage (7a)) and the import filter (60) may or may not be in direct contact with each other. And may be. In the case of exchanging the import filter (60), remove the nut (64), it may be Nukidase piping (high-pressure oil passage (7a)).
次に前記圧力制御バルブ(11)の振動防止対策について
説明する。Next, measures for preventing vibration of the pressure control valve (11) will be described.
まず圧力制御バルブ(11)の振動を第9図に示すように
上記制御ランドの制御溝(41)とバランス溝(41′)と
の間に角度θをもつチヤンフア(41a)を設けて防止す
る場合を説明する。制御ランドに(41a′)の外径をも
つチヤンフア(41a)がないと,圧力制御バルブ(11)
が第3図の停車位置から第4図の走行位置に移動して,
制御油路(7b)と制御溝(41)とが連通したときに,作
動油が制御油路(7b)から制御溝(41)へ急激に流入し
て,圧力制御バルブ(11)が振動するが,本パワーステ
アリング装置では,制御溝(41)とバランス溝(41′)
との間に角度(θ)をもつチヤンフア(41a)が設けら
れており,作動油が制御油路(7b)から制御溝(41)へ
緩やかに流入して,圧力制御バルブ(11)の振動が抑制
される。第16図の(θ1)はチヤンフア(41a)の角度
(θ)が小さい場合の,(θ2)はチヤンフア(41a)の
角度(θ)が(θ1)よりも大きい場合の,(θ3)はチ
ヤンフア(41a)の角度(θ)が(θ2)よりも大きい場
合の,〔ステアリングホイール入力トルク〕−〔油路
(7a)の油圧〕の特性変化の様相を示しており,チヤン
フア(41a)の角度(θ)は,制御油路(7b)の孔径と
の関係で同第16図に示す曲線の変曲点のカーブが緩やか
になるように選定されている。First, vibration of the pressure control valve (11) is prevented by providing a changer (41a) having an angle θ between the control groove (41) and the balance groove (41 ') of the control land as shown in FIG. The case will be described. If the control land does not have a changer (41a) with an outer diameter of (41a '), the pressure control valve (11)
Moves from the stop position in FIG. 3 to the running position in FIG.
When the control oil passage (7b) and the control groove (41) communicate with each other, hydraulic oil suddenly flows into the control groove (41) from the control oil passage (7b) and the pressure control valve (11) vibrates. However, in this power steering device, the control groove (41) and the balance groove (41 ')
A chamfer (41a) having an angle (θ) is provided between the pressure control valve (11) and the control oil passage (7b) to slowly flow into the control groove (41). Is suppressed. In Fig. 16, (θ 1 ) is when the angle (θ) of the channel (41a) is small, and (θ 2 ) is (θ 1 ) when the angle (θ) of the channel (41a) is larger than (θ 1 ). 3) Chiyanfua angle (theta) is larger than (theta 2) of (41a), [steering wheel input torque] - shows the appearance of a characteristic change of [oil pressure of the oil passage (7a)], Chiyanfua The angle (θ) of (41a) is selected so that the curve at the inflection point of the curve shown in FIG. 16 becomes gentle in relation to the hole diameter of the control oil passage (7b).
次に圧力制御バルブ(11)の上流側にインポート側オリ
フイスを設けて,圧力制御バルブ(11)の振動を防止す
る場合を説明する。ソレノイド(12)のプランジヤ(5
7)が昇降すると,前記関係式の成立する位置にバラン
スを保って保持されている圧力制御バルブ(11)が同プ
ランジヤ(57)の動きに追従して昇降する。このとき,
制御溝(41)の制御油路(7b)に対する開口量が変わっ
て,制御ランド(41)→油路(42)→差圧部(43)→制
御油路(7d)の系統の油圧が上記開口量に対応して変動
する。このとき,制御溝(41)前後の圧力差が大きい
と,圧力制御バルブ(11)が同圧力差に基づいて軸方向
に振動する場合がある。この対策としては,(I)第10
図に示すようにインポートフイルター(60)の部分にイ
ンポート側オリフイス(42′)を設けるか,(II)第11
図に示すようにインポートフイルター(60)と圧力制御
バルブ(11)との間の制御油路(7b)にインポート側オ
リフイス(42″)を設けるかして,高圧油路(7a)から
制御油路(7b)への作動油の流量を絞り,制御溝(41)
前後の圧力差を小さくして,圧力制御バルブ(11)の振
動を抑制する。第17図の(a)はインポート側オリフイ
スがない場合の油圧−入力特性〔油路(7b)のポンプ吐
出圧−ステアリングホイールの入力トルク〕特性を示
し,(b)は孔径の大きいインポート側オリフイスを使
用した場合の上記油圧−入力トルク特性を示し,(c)
は孔径の小さいインポート側オリフイスを使用した場合
の上記油圧−入力トルク特性を示しており,同油圧−入
力トルク特性がインポート側オリフイスの孔径により変
化する。特に第10図に示すインポート側オリフイス(4
2′)を使用する場合には,交換が可能で,自動車の仕
様に応じて上記油圧−入力トルク特性を任意に変えるこ
とができる。また第3,4図に示すように圧力制御バルブ
(11)の制御溝(41)と差圧部(43)との間の油路(4
2)の全体またはその一部をインポート側オリフイスに
してもよい。この場合には,制御溝(41)から差圧部
(43)への作動油の流量が絞られ,差圧部(43)に対す
る感度が鈍くなって,圧力制御バルブ(11)の振動が抑
制される。なお上記のようにインポート側オリフイスが
ある場合には,差圧部に作用する油圧が絞られるので,
反力ピストン(5)に作用する油圧も小さくなり,結果
的に小さなトルクで同一のポンプ吐出圧(油路(7a)の
圧力)を得ることができる。Next, a case where an import-side orifice is provided upstream of the pressure control valve (11) to prevent vibration of the pressure control valve (11) will be described. Plunger (5) for solenoid (12)
When 7) moves up and down, the pressure control valve (11) held in balance at the position where the relational expression holds holds moves up and down following the movement of the plunger (57). At this time,
The opening amount of the control groove (41) with respect to the control oil passage (7b) is changed so that the hydraulic pressure of the system of the control land (41) → oil passage (42) → differential pressure section (43) → control oil passage (7d) becomes the above. It changes according to the opening amount. At this time, if the pressure difference before and after the control groove (41) is large, the pressure control valve (11) may vibrate in the axial direction based on the pressure difference. As measures against this, (I) No. 10
As shown in the figure, install an import side orifice (42 ') in the import filter (60) or (II) No. 11
As shown in the figure, the control oil passage (7b) between the import filter (60) and the pressure control valve (11) is provided with an import side orifice (42 ″) or the control oil passage from the high pressure oil passage (7a). Reduce the flow rate of hydraulic oil to the channel (7b), and control groove (41)
The pressure difference between the front and back is reduced to suppress the vibration of the pressure control valve (11). Figure 17 (a) shows the hydraulic-input characteristics [pump discharge pressure of oil passage (7b) -steering wheel input torque] characteristics when there is no import-side orifice, and (b) shows the import-side orifice with a large hole diameter. Shows the above-mentioned hydraulic pressure-input torque characteristics when using
Shows the oil pressure-input torque characteristics when an import-side orifice with a small hole diameter is used. The oil pressure-input torque characteristics vary depending on the hole diameter of the import-side orifice. In particular, the import side orifice (4
When 2 ') is used, it can be replaced and the above hydraulic pressure-input torque characteristics can be arbitrarily changed according to the specifications of the vehicle. Further, as shown in FIGS. 3 and 4, the oil passage (4) between the control groove (41) of the pressure control valve (11) and the differential pressure portion (43).
The whole or part of 2) may be used as the import side orifice. In this case, the flow rate of the hydraulic oil from the control groove (41) to the differential pressure section (43) is reduced, the sensitivity to the differential pressure section (43) is reduced, and vibration of the pressure control valve (11) is suppressed. To be done. If there is an import side orifice as described above, the hydraulic pressure acting on the differential pressure section will be throttled.
The hydraulic pressure acting on the reaction force piston (5) is also reduced, and as a result, the same pump discharge pressure (pressure in the oil passage (7a)) can be obtained with a small torque.
次に制御油路(7d)での油圧の立ち上がり位相遅れを防
止することにより圧力制御バルブ(11)の振動を防止す
る場合を説明する。既に述べたように,ソレノイド(1
2)のプランジヤ(57)が昇降すると,前記関係式の成
立する位置にバランスを保って保持されている圧力制御
バルブ(11)が同プランジヤ(57)の動きに追従して昇
降する。このとき,制御溝(41)の制御油路(7b)に対
する開口量が変わって,制御溝(41)→油路(42)→差
圧部(42)→制御油路(7d)の系統の油圧が上記開口量
に対応して変動する。この際,リターン側オリフイス
(13)が圧力制御バルブ(11)の近くにあればある程,
差圧部(43)及び制御油路(7d)での油圧の立ち方が遅
くなる。そのため,ソレノイド(12)のプランジヤ(5
7)が下降するとき,本来なら差圧部(43)の油圧によ
り,その下降が抑制されて,バランスが保たれるはずな
のに,前述のように差圧部(43)及び制御油路(7d)の
油圧の立ち上がり方が遅くなるので(制御溝(41))と
差圧部(43)との圧力の立ち上がりに位相遅れを生ずる
ので),圧力制御バルブ(11)が必要以上に下降してし
まう。そのため,制御溝(41)の制御油路(7b)に対す
る開口量が大きくなり過ぎ,油路(42)及び差圧部(4
3)の圧力が急激に高くなって,今度は逆に圧力制御バ
ルブ(11)が上昇を始める。このように圧力制御バルブ
(11)の動きと差圧部(43)の油圧とに位相遅れを生じ
て,圧力制御バルブ(11)が軸方向に振動する。この振
動を防止するためには,(I)第12図に示すようにリタ
ーン側オリフイス(13)をシリンダブロツク(23)に設
けるか,(II)同第12図に破線で示すように反力ピスト
ン(5)背後のチヤンバー(6)と圧力制御バルブ(1
1)下方のチヤンバー(56)との間にリターン側オリフ
イスを設けるか,(III)同第12図に破線で示すように
制御油路(7d)と上記チヤンバー(56)との間にリター
ン側オリフイスを設けるかして,つまりリターン側オリ
フイスを圧力制御バルブ(11)の下流側に設けて,差圧
部(43)及び制御油路(7d)での油圧の立ち上がりの遅
れを防止するのが有効である。Next, a case will be described in which the vibration of the pressure control valve (11) is prevented by preventing the rising phase delay of the hydraulic pressure in the control oil passage (7d). As already mentioned, the solenoid (1
When the plunger (57) of 2) moves up and down, the pressure control valve (11) held in balance at the position where the above relational expression is satisfied moves up and down following the movement of the plunger (57). At this time, the opening amount of the control groove (41) with respect to the control oil passage (7b) changes, and the control groove (41) → oil passage (42) → differential pressure section (42) → control oil passage (7d) system The hydraulic pressure fluctuates corresponding to the opening amount. At this time, the closer the return-side orifice (13) is to the pressure control valve (11),
How the hydraulic pressure rises in the differential pressure section (43) and the control oil passage (7d) is delayed. Therefore, the solenoid (12) plunger (5
When 7) descends, the hydraulic pressure of the differential pressure section (43) would normally have to suppress the downward pressure and maintain balance, but as mentioned above, the differential pressure section (43) and the control oil passage (7d ), The rise of the oil pressure is delayed (because there is a phase delay in the rise of the pressure between the control groove (41)) and the differential pressure section (43), and the pressure control valve (11) is lowered more than necessary. I will end up. Therefore, the opening amount of the control groove (41) with respect to the control oil passage (7b) becomes too large, and the oil passage (42) and the differential pressure section (4).
The pressure in 3) rises sharply, and this time the pressure control valve (11) starts to rise. In this way, a phase delay occurs between the movement of the pressure control valve (11) and the hydraulic pressure of the differential pressure section (43), and the pressure control valve (11) vibrates in the axial direction. To prevent this vibration, (I) provide a return-side orifice (13) on the cylinder block (23) as shown in FIG. 12, or (II) reaction force as shown by the broken line in FIG. The chamber (6) behind the piston (5) and the pressure control valve (1
1) Provide a return-side orifice with the lower chamber (56), or (III) Return side between the control oil passage (7d) and the above-mentioned chamber (56) as indicated by the broken line in FIG. By providing an orifice, that is, by providing a return orifice on the downstream side of the pressure control valve (11), it is possible to prevent a delay in the rise of hydraulic pressure in the differential pressure section (43) and the control oil passage (7d). It is valid.
次に圧力制御バルブ(11)の差圧部(43)を制御ランド
の位置に設けて,圧力制御バルブ(11)の振動を防止す
る場合を説明する。ソレノイド(12)のプランジヤ(5
7)が昇降すると,圧力制御バルブ(11)も同プランジ
ヤ(57)の昇降に追従して昇降する。このとき,制御油
路(7b)の油圧が制御溝(41)→油路(インポート側オ
リフイス)(42)を介して差圧部(43)に伝えられる
と,圧力制御バルブ(11)に前述のように応答遅れを生
じるが,第14図のように制御ランドの部分に差圧部(4
3)を設けると,同差圧部(43)がインポートに近くな
り、圧力フイードバツクのレスポンスが向上して,応答
遅れが防止され,それに伴い圧力制御バルブ(11)の振
動が抑制される。Next, a case where the differential pressure portion (43) of the pressure control valve (11) is provided at the position of the control land to prevent vibration of the pressure control valve (11) will be described. Plunger (5) for solenoid (12)
When 7) goes up and down, the pressure control valve (11) also goes up and down following the up and down movement of the plunger (57). At this time, when the hydraulic pressure of the control oil passage (7b) is transmitted to the differential pressure section (43) via the control groove (41) → the oil passage (import side orifice) (42), the pressure control valve (11) is described above. However, as shown in Fig. 14, the differential pressure part (4
By providing 3), the differential pressure section (43) becomes closer to the import, the response of the pressure feedback is improved, the response delay is prevented, and the vibration of the pressure control valve (11) is suppressed accordingly.
次に前記制御装置(コントローラ)を第15図により具体
的に説明すると,(16)がイグニシヨンスイツチ,(6
0)が車速センサ(14)からの車速信号入力部,(61)
がソレノイド(12)の通電チエツク機能を有するソレノ
イド通電テストスイツチである。なお本パワーステアリ
ング装置は,アイドリング停車時にソレノイド(12)に
最大値の電流が流れており,同パワーステアリング装置
を最も軽い力で操舵できるが,この状態でダイアグノシ
ステスタを使用すると,ソレノイド(12)に流れる電流
を最大値の略半分以下にすることができ,停車状態で中
・高速走行時の操舵特性を確認できる。同ソレノイド通
電テストスイツチ(61)は,そのために設けられてい
る。また(62)が特性切換えスイツチ,(63)がエンジ
ンの点火信号(イクニシヨンコイル−端子)により感知
するエンジン回転数信号,(64)が電源回路,(65)が
周波数→電圧変換回路,(66)が特性切換回路で,同特
性切換回路(66)は,上記特性切換えスイツチ(62)の
切換え操作により,第11図に示すように車速に応じたソ
レノイド電流を選択できるようになっている。また(6
7)が誤差増幅器,(68)が機械的なヒステリシスを減
少させるために低周波振動を加えるデイザ用発信器,
(69)が磁気的なヒステリシスを減少させるために低周
波振動を加えるPWM用発信器,(70)が誤差デユーテイ
変換回路,(71)がソレノイド駆動回路,(72)がフイ
ルタ回路,(73)が増幅回路,(74)が過電圧検出回路
で,同過電圧検出回路(74)は,上記電源回路(64)の
故障等により同電源回路(64)の各部に過電圧がかかっ
たときに,制御装置(15)のリレーをONにするようにな
っている。また(75)が帰還異常検出回路で,同帰還異
常検出回路(75)は,ソレノイド(12)の電磁コイルや
車体ハーネス等の故障によりソレノイド電流制御特性に
異常が発生したときに,制御装置(15)のリレーをONに
するようになっている。また(76)が過電流検出回路
で,同過電流検出回路(76)は,上記ソレノイド駆動回
路(71)の故障等によりソレノイド(12)への電流が異
常に増加したときに,制御装置(15)のリレーをONにす
るようになっている。また(77)が周波数→電圧変換回
路,(78)がエンジン回転数検出回路,(79)がタイマ
ー回路で,同タイマー回路(79)は,高速走行時に車速
信号が所定時間以上入力しないと,車速センサ(14)ま
たはハーネスに異常が発生したと判断して,イグニシヨ
ンスイツチ(16)がOFFになるまでリレーをONにするよ
うになっている。以上の各機器により構成された制御装
置(15)は,(I)車速センサ(14)からのパルス信号
により,ソレノイド(12)に流れる電流を車速に反比例
して減少させる車速感応機能と,(II)電気系統に故障
が発生しても,制御装置(15)内のリレーをONにして,
ソレノイド(12)への出力電流を遮断し,イグニシヨン
スイツチ(16)をOFF(ACCまたはLOCK位置)にするま
で,その状態を保持するというフエイルセーフ機能と,
(III)ソレノイド(12)の通電チエツク機能と,(I
V)車速に応じたソレノイド電流特性の選択機能とを有
している。なお上記(II)のフエイルセーフ機能が働い
たときの操舵特性は,中・高走行時の特性になっている
ため,正常なときと同じ安全な走行になる。Next, the control device (controller) will be described in detail with reference to FIG. 15. (16) is an ignition switch, and (6)
0) is the vehicle speed signal input from the vehicle speed sensor (14), (61)
Is a solenoid energization test switch having a solenoid (12) energization check function. In this power steering system, the maximum current flows through the solenoid (12) when the vehicle is idling, and the power steering system can be steered with the lightest force. However, if the diagnostic system tester is used in this state, the solenoid (12) It is possible to reduce the current that flows to approximately half of the maximum value, and to confirm the steering characteristics during medium and high speed running when the vehicle is stopped. The solenoid energization test switch (61) is provided for that purpose. Further, (62) is a characteristic switching switch, (63) is an engine speed signal sensed by an engine ignition signal (ignition coil-terminal), (64) is a power supply circuit, (65) is a frequency → voltage conversion circuit, ( 66) is a characteristic switching circuit, and the characteristic switching circuit (66) can select a solenoid current according to the vehicle speed as shown in FIG. 11 by switching the characteristic switching switch (62). . Also (6
7) is an error amplifier, (68) is a dither oscillator that applies low-frequency vibration to reduce mechanical hysteresis,
(69) PWM oscillator that applies low-frequency vibration to reduce magnetic hysteresis, (70) error duty conversion circuit, (71) solenoid drive circuit, (72) filter circuit, (73) Is an amplifier circuit, and (74) is an overvoltage detection circuit. The overvoltage detection circuit (74) is a control device when an overvoltage is applied to each part of the power supply circuit (64) due to a failure of the power supply circuit (64). It is designed to turn on the relay of (15). Further, (75) is a feedback abnormality detection circuit. The feedback abnormality detection circuit (75) controls the controller (when the abnormality in the solenoid current control characteristic occurs due to a failure of the solenoid coil of the solenoid (12), the vehicle body harness, or the like. It turns on the relay of 15). Further, (76) is an overcurrent detection circuit, and when the current to the solenoid (12) abnormally increases due to a failure of the solenoid drive circuit (71) or the like, the overcurrent detection circuit (76) controls the controller ( It turns on the relay of 15). Further, (77) is a frequency-to-voltage conversion circuit, (78) is an engine speed detection circuit, and (79) is a timer circuit. The timer circuit (79) has to input a vehicle speed signal for a predetermined time or more during high-speed traveling. It judges that an abnormality has occurred in the vehicle speed sensor (14) or harness and turns on the relay until the ignition switch (16) turns off. The control device (15) composed of the above devices has (I) a vehicle speed responsive function of reducing the current flowing through the solenoid (12) in inverse proportion to the vehicle speed by a pulse signal from the vehicle speed sensor (14), II) Even if a failure occurs in the electrical system, turn on the relay in the control device (15),
A fail-safe function that keeps that state until the output current to the solenoid (12) is cut off and the ignition switch (16) is turned off (ACC or LOCK position).
(III) Energizing check function of solenoid (12)
V) It has the function of selecting the solenoid current characteristics according to the vehicle speed. Note that the steering characteristics when the fail-safe function of (II) above is activated are the characteristics for medium and high running, so the driving is as safe as normal.
次に前記パワーステアリング装置の作用を具体的に説明
する。油路切換弁(2)の出力油圧(オイルポンプ
(1)の吐出圧)はPpは,ステアリングホイール(2a)
を中立位置から右または左に切って,入力軸(21)のバ
ルブボデイ(27)に対応する相対回転角度が大きくなれ
ば,第21図に示すように2次曲線を描いて上昇する。こ
のオイルポンプ(1)の吐出圧Ppの影響は,高圧油路
(7a)や制御油路(7b)にそのまま表れて,同制御油路
(7b)の油圧が同様に上昇する。このとき,自動車が停
止していれば,制御装置(15)は,車速センサ(14)か
らのパルス信号がないので,所定の最大電流をソレノイ
ド(12)へ送り,プランジヤ(57)を第3図の位置まで
上昇させる。このとき,圧力制御バルブ(11)も同プラ
ンジヤ(57)の上昇に追従して同第3図の位置までばね
(19)に抗し上昇して,制御油路(7b)(7c)の連通が
同圧力制御バルブ(11)により遮断される。そのため,
同圧力制御バルブ(11)よりも下流側の制御油路(7c)
(7d)(7e)の油圧は,最も低くて,反力ピストン
(5)の背後のチヤンバー(6)の油圧も最も低くな
る。この状態は,それからも同じで,ステアリングホイ
ール(2a)をさらに右または左に切って,高圧油路(7
a)や制御油路(7b)の油路Ppがさらに上昇しても,圧
力制御バルブ(11)は,制御油路(7b)を制御油路(7
c)(7d)(7e)の油圧を最も低い状態に保持する。こ
のときの制御油路(7b)と制御油路(7d)との圧力関係
は,第18図の停車時の通りになる。従って前記相対回転
角度を大きくして,大きな出力油圧Ppを得るときに,反
力ピストン(5)背後のチヤンバー(6)の油圧とトー
シヨンバー(22)の捩れ角度とで決まるステアリングホ
イール(2a)のトルクTが大きくならない。Next, the operation of the power steering device will be specifically described. The output hydraulic pressure of the oil passage switching valve (2) (the discharge pressure of the oil pump (1)) is Pp, which is the steering wheel (2a).
If the relative rotation angle corresponding to the valve body (27) of the input shaft (21) is increased by turning from the neutral position to the right or left, it rises by drawing a quadratic curve as shown in FIG. The influence of the discharge pressure Pp of the oil pump (1) appears in the high pressure oil passage (7a) and the control oil passage (7b) as it is, and the oil pressure of the control oil passage (7b) similarly rises. At this time, if there is no pulse signal from the vehicle speed sensor (14) if the vehicle is stopped, the control device (15) sends a predetermined maximum current to the solenoid (12) and causes the plunger (57) to move to the third position. Raise to the position shown. At this time, the pressure control valve (11) also follows the rise of the plunger (57) and rises up to the position shown in FIG. 3 against the spring (19), thereby communicating the control oil passages (7b) (7c). Is shut off by the pressure control valve (11). for that reason,
Control oil passage (7c) downstream of the pressure control valve (11)
The hydraulic pressures of (7d) and (7e) are the lowest, and the hydraulic pressure of the chamber (6) behind the reaction force piston (5) is also the lowest. This state is the same from then on, by turning the steering wheel (2a) further to the right or left, and
Even if a) or the oil passage Pp of the control oil passage (7b) further rises, the pressure control valve (11) moves the control oil passage (7b) to the control oil passage (7b).
c) Keep the hydraulic pressures of (7d) and (7e) at the lowest level. The pressure relationship between the control oil passage (7b) and the control oil passage (7d) at this time is as shown in FIG. 18 when the vehicle is stopped. Therefore, when the relative rotation angle is increased to obtain a large output hydraulic pressure Pp, the steering wheel (2a) is determined by the hydraulic pressure of the chamber (6) behind the reaction force piston (5) and the torsion angle of the torsion bar (22). Torque T does not increase.
また自動車が低速走行状態に入れば,制御装置(15)
は,車速センサ(14)からのパルス信号を受けて,その
ときの車速に対応した電流をソレノイド(12)へ送り,
プランジヤ(57)を同電流値に対応する量だけ下降させ
る。このとき,第4図に示すように圧力制御バルブ(1
1)は,ばね(19)によりプランジヤ(57)の下降量だ
け下降して,制御溝(41)の一部が制御油路(7b)に連
通し,同制御溝(41)と油路(42)と制御油路(7c)
(7d)(7e)と反力ピストン(5)背後のチヤンバー
(6)とに圧力が立って,同チヤンバー(6)の油圧が
上記停車時よりも高くなる。以上の低速時にステアリン
グホイール(2a)を右または左に切ると,高圧油路(7
a)や制御油路(7b)の油路Ppが上昇するが,上記制御
油路(7c)(7d)(7e)及び反力ピストン(5)背後の
チヤンバー(6)に作用する油圧は,プランジヤ(57)
の軸出力の低下量に応じて停車時よりも高い一定レベル
に制御される。このときの制御油路(7b)と制御油路
(7d)との圧力関係は,第18図の低速時の通りになる。
従って前記相対回転角度を大きくして,大きな出力Pp
を得るときには,ステアリングホイール(2a)のトルク
Tが前記停車時よりは大きくなるが,後記高速走行時の
ようには大きくならない。このとき,上記チヤンバー
(6)内に供給された作動油は,リターン側オリフイス
(13)→油路(45)→油路(46)→チヤンバー(29)→
低圧油路(8b)→低圧油路(8a)を経てオイルタンク
(4)へ戻って,オイルポンプ(1)により再び吸引さ
れる。In addition, if the car enters a low speed running state, the control device (15)
Receives a pulse signal from the vehicle speed sensor (14), sends a current corresponding to the vehicle speed at that time to the solenoid (12),
The plunger (57) is lowered by an amount corresponding to the same current value. At this time, as shown in Fig. 4, the pressure control valve (1
1) is lowered by the lowering amount of the plunger (57) by the spring (19), a part of the control groove (41) communicates with the control oil passage (7b), and the control groove (41) and the oil passage ( 42) and control oil passage (7c)
(7d) and (7e) and pressure on the chamber (6) behind the reaction force piston (5) raise the pressure of the chamber (6) higher than that when the vehicle is stopped. When the steering wheel (2a) is turned to the right or left at the above low speed, the high pressure oil passage (7
a) and the oil passage Pp of the control oil passage (7b) rise, but the oil pressure acting on the control oil passages (7c) (7d) (7e) and the chamber (6) behind the reaction force piston (5) is Plungeers (57)
Is controlled to a constant level higher than that when the vehicle is stopped according to the amount of reduction in the shaft output of. The pressure relationship between the control oil passage (7b) and the control oil passage (7d) at this time is as shown in FIG.
Therefore, by increasing the relative rotation angle, a large output P p
In order to obtain, the torque T of the steering wheel (2a) becomes larger than that when the vehicle is stopped, but does not become so large as when the vehicle runs at a high speed, which will be described later. At this time, the hydraulic oil supplied into the chamber (6) is the return side orifice (13) → oil passage (45) → oil passage (46) → chamber (29) →
It returns to the oil tank (4) through the low pressure oil passage (8b)-> low pressure oil passage (8a), and is sucked again by the oil pump (1).
また自動車が所定の高速走行状態に入れば,制御装置
(15)が車速センサ(14)からのパルス信号を受けて,
ソレノイド(12)への電流を略零にして,プランジヤ
(57)を下限位置まで下降させる。このとき,圧力制御
バルブ(11)は,ばね(19)によりプランジヤ(57)の
下降量だけ下降して,制御溝(41)の殆どが制御油路
(7b)に連通する。以上の高速走行時に,ステアリング
ホイール(2a)を右または左に切ると,高圧油路(7a)
や制御油路(7b)の油路Ppが上昇するが,上記制御油路
(7c)(7d)(7e)及び反力ピストン(5)背後のチヤ
ンバー(6)に作用する油圧は,プランジヤ(57)の軸
力が略零になるので,低速走行時よりも高い一定レベル
に制御される。このときの制御油路(7b)と制御油路
(7d)との圧力関係は,第18図の高速時の通りになる。
従って前記相対回転角度を大きくして,大きな出力Pp
を得るときには,ステアリングホイール(2a)のトルク
Tが前記低速走行時よりもさらに大きくなる。このとき
にも,上記チヤンバー(6)内に供給された作動油は,
オリフイス(13)→油路(45)→油路(46)→チヤンバ
ー(29)→低圧油路(8b)→低圧油路(8a)を経てオイ
ルタンク(4)へ戻って,オイルポンプ(1)に再び吸
引される。When the vehicle enters a predetermined high speed running state, the control device (15) receives a pulse signal from the vehicle speed sensor (14),
The current to the solenoid (12) is made almost zero and the plunger (57) is lowered to the lower limit position. At this time, the pressure control valve (11) is lowered by the lowering amount of the plunger (57) by the spring (19), and most of the control groove (41) communicates with the control oil passage (7b). When driving the steering wheel (2a) to the right or left during the above high-speed running, the high-pressure oil passage (7a)
And the oil passage Pp of the control oil passage (7b) rises, but the hydraulic pressure acting on the control oil passages (7c) (7d) (7e) and the chamber (6) behind the reaction force piston (5) is increased by the plunger ( Since the axial force of 57) becomes almost zero, it is controlled to a constant level higher than that during low speed running. The pressure relationship between the control oil passage (7b) and the control oil passage (7d) at this time is as shown in FIG. 18 at high speed.
Therefore, by increasing the relative rotation angle, a large output P p
In order to obtain, the torque T of the steering wheel (2a) becomes larger than that at the time of low speed running. Also at this time, the hydraulic oil supplied to the chamber (6) is
The oil pump (1) returns to the oil tank (4) via the orifice (13) → oil passage (45) → oil passage (46) → chamber (29) → low pressure oil passage (8b) → low pressure oil passage (8a). ) Is sucked again.
第21図の各曲線は,停車時から高速走行時までの各車速
に対応したステアリングホイール(2a)の入力トルクと
オイルポンプ吐出圧との特性変化の様相を示している。The curves in Fig. 21 show the changes in the characteristics of the input torque of the steering wheel (2a) and the oil pump discharge pressure corresponding to each vehicle speed from when the vehicle is stopped to when the vehicle runs at high speed.
(考案の効果) 本考案は前記のように圧力制御バルブ(11)の両端に面
したバルブハウジング(20a)内のチヤンバー(54)(5
6)を形成して,同各チヤンバー(54)(56)の一方(5
4)を低圧油路(8b)に連通するとともに,同各チヤン
バー(54)(56)を同圧力制御バルブ(11)内に設けた
ドレン油路(55)により連通し,同圧力制御バルブ(1
1)の外周面に環状の制御溝(41)及び差圧部(43)を
設けるとともに,同各制御溝(41)及び差圧部(43)を
同圧力制御バルブ(11)内に設けた油路(42)により連
通しており,圧力制御バルブの両端部に面したチヤンバ
ーを連通するドレン油路や制御溝及び差圧部を連通する
油路をバルブハウジング内に設けたり,バルブハウジン
グの外面に開口する開口部をメクラボールによりシール
必要がなくて,工数を低減できる。また上記各油路が圧
力制御バルブ(11)内に設けられて,作動油に混入して
いる空気の溜りを形成しないので,同空気がメクラボー
ル直下の油路等に溜まって生じていた制御上の不都合を
解消できる効果がある。(Effect of the Invention) As described above, the present invention is provided with the chamber (54) (5) in the valve housing (20a) facing both ends of the pressure control valve (11).
6) to form one of the chambers (54) (56) (5)
4) is connected to the low pressure oil passage (8b), and the respective chambers (54) and (56) are connected to each other via the drain oil passage (55) provided in the same pressure control valve (11). 1
An annular control groove (41) and a differential pressure portion (43) are provided on the outer peripheral surface of 1), and each control groove (41) and differential pressure portion (43) are provided in the same pressure control valve (11). A drain oil passage communicating with the chamber facing both ends of the pressure control valve and an oil passage communicating with the control groove and the differential pressure portion are provided in the valve housing, or communicate with each other through the oil passage (42). Since it is not necessary to seal the opening that opens to the outside with a blind ball, the number of steps can be reduced. In addition, since each of the oil passages is provided in the pressure control valve (11) and does not form a pool of air mixed in with the hydraulic oil, the air is accumulated in the oil passage immediately below the blind ball, etc. There is an effect that the above inconvenience can be eliminated.
第1図は本考案に係わるパワーステアリング装置の一実
施例の油圧回路図,第2図は油路切換弁及び圧力制御バ
ルブ部分の縦断一側面図,第3図は同油路切換弁及び圧
力制御バルブ部分の停車時における縦断他側面図,第4
図は同油路切換弁及び圧力制御バルブ部分の走行時にお
ける縦断他側面図,第5図は同圧力制御バルブ及び反力
ピストン部分の横断平面図,第6図はインポートフイル
タの第7図矢視VI-VI線に沿う横断平面図,第7図は同
インポートフイルタの側面図,第8図は同インポートフ
イルタの拡大斜視図,第9図は制御ランドに設けたチヤ
ンフアの縦断側面図,第10図はインポート側オリフイス
の一例を示す横断平面図,第11図は同インポート側オリ
フイスの他の例を示す横断平面図,第12図はリターン側
オリフイスの各例を示す縦断側面図,第13図は同リター
ン側オリフイスのさらに他の例を示す縦断側面図,第14
図は圧力制御バルブの差圧部の他の例を示す縦断側面
図,第15図は制御装置の系統図,第16図は制御ランドに
設けたチヤンフアの角度により変わる油圧−入力特性説
明図,第17図はインポートオリフイスの孔径により変わ
る油圧−入力特性説明図,第18図は圧力制御バルブ上流
側制御油路の油圧と圧力制御バルブ下流側制御油路の油
圧との関係を示す説明図,第19図はソレノイドのプラン
ジヤのストロークと軸力との関係を示す説明図,第20図
は車速とソレノイド電流との関係を示す説明図,第21図
は入力トルク−オイルポンプ吐出圧特性を示す説明図で
ある。 (1)……オイルポンプ,(2)……油路切換弁,(2
a)……ステアリングホイール,(3)……パワーシリ
ンダ,(4)……オイルタンク,(5)……反力ピスト
ン,(7a)……高圧油路、(7b)(7c)(7d)(7e)…
…制御油路,(8a)(8b)……低圧油路,(11)……圧
力制御バルブ,(12)……ソレノイド,(13)……オリ
フイス,(20a)……ハルブハウジング,(21)……入
力軸,(22)……トーシヨンバー,(24a)……出力
軸,(41)……制御溝,(42)……油路,(43)……差
圧部,(54)……チヤンバー,(55)……ドレン油路。FIG. 1 is a hydraulic circuit diagram of an embodiment of a power steering device according to the present invention, FIG. 2 is a side view of an oil passage switching valve and a pressure control valve, and FIG. Side view of a vertical section of the control valve when the vehicle is stopped, No. 4
The figure shows a side view of the oil passage switching valve and the pressure control valve section during running, etc., Fig. 5 is a cross-sectional plan view of the pressure control valve and reaction piston section, and Fig. 6 is the import filter Fig. 7 arrow. VI-VI line of view, FIG. 7 is a side view of the import filter, FIG. 8 is an enlarged perspective view of the import filter, and FIG. 9 is a vertical side view of the chain fan provided on the control land. Fig. 10 is a cross-sectional plan view showing an example of the import-side orifice, Fig. 11 is a cross-sectional plan view showing another example of the import-side orifice, and Fig. 12 is a vertical side view showing each example of the return-side orifice. The figure is a vertical sectional side view showing another example of the return side orifice, 14th
Figure is a vertical sectional side view showing another example of the differential pressure section of the pressure control valve, Figure 15 is a system diagram of the control device, and Figure 16 is a hydraulic-input characteristic explanatory diagram that changes depending on the angle of the changer provided on the control land. FIG. 17 is an explanatory diagram of the hydraulic pressure-input characteristic that changes depending on the hole diameter of the import orifice, and FIG. 18 is an explanatory diagram showing the relationship between the hydraulic pressure of the control oil passage on the upstream side of the pressure control valve and the hydraulic pressure of the control oil passage on the downstream side of the pressure control valve. FIG. 19 is an explanatory view showing the relationship between the stroke of the plunger of the solenoid and the axial force, FIG. 20 is an explanatory view showing the relationship between the vehicle speed and the solenoid current, and FIG. 21 shows the input torque-oil pump discharge pressure characteristic. FIG. (1) …… Oil pump, (2) …… Oil passage switching valve, (2
a) ... Steering wheel, (3) ... Power cylinder, (4) ... Oil tank, (5) ... Reaction force piston, (7a) ... High pressure oil passage, (7b) (7c) (7d) (7e) ...
… Control oil passage, (8a) (8b) …… Low pressure oil passage, (11) …… Pressure control valve, (12) …… Solenoid, (13) …… Orifice, (20a) …… Halve housing, (21 ) …… Input shaft, (22) …… Torsion bar, (24a) …… Output shaft, (41) …… Control groove, (42) …… Oil passage, (43) …… Differential pressure section, (54)… … Chamber, (55) …… Drain oil passage.
フロントページの続き (56)参考文献 特開 昭53−109334(JP,A) 実開 昭59−83666(JP,U) 実公 昭51−25072(JP,Y2)Continuation of the front page (56) Reference JP-A-53-109334 (JP, A) Actual development S59-83666 (JP, U) Actual public S51-25072 (JP, Y2)
Claims (1)
と、同入力軸の回転を出力軸に伝えるトーションバー
と、同出力軸に連結されたパワーシリンダと、上記入力
軸と上記出力軸との回転角度差に応じて上記パワーシリ
ンダへの油路を切換える油路切換弁と、オイルポンプか
ら吐出される作動油を上記油路切換弁を介して上記パワ
ーシリンダへ供給する高圧油路と、上記パワーシリンダ
から上記油路切換弁を介してオイルタンクへ作動油を戻
す低圧油路と、上記入力軸と上記出力軸との間で規制力
を付与して同各軸の回転角度差を制限する反力ピストン
と、上記高圧油路の途中から上記反力ピストンへ延びた
制御油路と、両端に面したバルブハウジング内にチャン
バーが形成され上記反力ピストンへ延びた上記制御油路
に介装され上記反力ピストンに作用する油圧の上昇と共
に圧力制御用ばねの付勢力に抗して変位し上記油圧を所
定の最高圧以下に制御する圧力制御バルブと、同圧力制
御バルブと上記反力ピストンとの間の上記制御油路を上
記低圧油路に連通させるリターン側オリフィスと、車速
に応じて変わり且つ車速毎に略一定の軸力を発生するプ
ランジャを介して上記ばねに対抗して上記圧力制御バル
ブを変位させるソレノイドとを具えているパワーステア
リング装置において、上記各チャンバーの一方を上記低
圧油路に連通し、同各チャンバーを互いに連通するドレ
ン油路を上記圧力制御バルブ内に設けると共に、上記圧
力制御バルブの外周面に形成され上記圧力制御バルブの
変位に応じて作動油の流量を制御する環状の制御溝と上
記圧力制御バルブの外周面に形成され上記反力ピストン
に作用する油圧に応じた差圧を発生し上記圧力制御バル
ブを変位させる力を発生する差圧部とを互いに連通する
油路を上記ドレン油路と連通しないように上記圧力制御
バルブ内に設けたことを特徴とするパワーステアリング
装置。1. An input shaft connected to a steering wheel, a torsion bar for transmitting rotation of the input shaft to an output shaft, a power cylinder connected to the output shaft, and rotation of the input shaft and the output shaft. An oil passage switching valve that switches the oil passage to the power cylinder according to the angle difference, a high-pressure oil passage that supplies hydraulic oil discharged from an oil pump to the power cylinder via the oil passage switching valve, and the power A low-pressure oil passage that returns hydraulic oil from a cylinder to the oil tank via the oil passage switching valve, and a restriction force between the input shaft and the output shaft to limit the rotational angle difference between the shafts. A force piston, a control oil passage extending from the middle of the high pressure oil passage to the reaction force piston, and a chamber formed in a valve housing facing both ends, and a control oil passage extending to the reaction force piston. Above reaction force Between the pressure control valve that displaces against the biasing force of the pressure control spring and controls the hydraulic pressure below a predetermined maximum pressure as the hydraulic pressure acting on the stone increases, and between the pressure control valve and the reaction force piston. The pressure control valve is displaced against the spring through a return-side orifice that communicates the control oil passage with the low-pressure oil passage and a plunger that changes according to the vehicle speed and generates a substantially constant axial force for each vehicle speed. In the power steering device including a solenoid for controlling the pressure control valve, one of the chambers is connected to the low pressure oil passage, and a drain oil passage for communicating the chambers with each other is provided in the pressure control valve. Is formed on the outer peripheral surface of the pressure control valve and an annular control groove that controls the flow rate of hydraulic oil according to the displacement of the pressure control valve. The pressure control is performed so that the oil passage that communicates with a differential pressure portion that generates a pressure difference corresponding to the hydraulic pressure acting on the reaction force piston and generates a force that displaces the pressure control valve does not communicate with the drain oil passage. A power steering device characterized by being provided in a valve.
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1985116442U JPH0728050Y2 (en) | 1985-07-31 | 1985-07-31 | Power steering device |
GB08617473A GB2179900B (en) | 1985-07-31 | 1986-07-17 | Power steering system |
US06/888,436 US4787469A (en) | 1985-07-31 | 1986-07-23 | Power steering system |
FR8610881A FR2585660B1 (en) | 1985-07-31 | 1986-07-28 | POWER STEERING SYSTEM FOR MOTOR VEHICLE |
DE19863625600 DE3625600A1 (en) | 1985-07-31 | 1986-07-29 | SERVOLINE SYSTEM |
KR1019860006299A KR920002738B1 (en) | 1985-07-31 | 1986-07-31 | Power steering system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1985116442U JPH0728050Y2 (en) | 1985-07-31 | 1985-07-31 | Power steering device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6225264U JPS6225264U (en) | 1987-02-16 |
JPH0728050Y2 true JPH0728050Y2 (en) | 1995-06-28 |
Family
ID=31001033
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1985116442U Expired - Lifetime JPH0728050Y2 (en) | 1985-07-31 | 1985-07-31 | Power steering device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0728050Y2 (en) |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5125072U (en) * | 1974-08-12 | 1976-02-24 | ||
JPS5983666U (en) * | 1982-11-30 | 1984-06-06 | 三菱自動車工業株式会社 | power steering device |
-
1985
- 1985-07-31 JP JP1985116442U patent/JPH0728050Y2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPS6225264U (en) | 1987-02-16 |
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