JPH01262257A - Hydraulic control valve - Google Patents
Hydraulic control valveInfo
- Publication number
- JPH01262257A JPH01262257A JP9003588A JP9003588A JPH01262257A JP H01262257 A JPH01262257 A JP H01262257A JP 9003588 A JP9003588 A JP 9003588A JP 9003588 A JP9003588 A JP 9003588A JP H01262257 A JPH01262257 A JP H01262257A
- Authority
- JP
- Japan
- Prior art keywords
- circumferential surface
- casing
- notch
- oil
- valve body
- 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.)
- Granted
Links
- 239000003921 oil Substances 0.000 claims description 51
- 230000008859 change Effects 0.000 claims description 15
- 238000006073 displacement reaction Methods 0.000 description 22
- 230000002093 peripheral effect Effects 0.000 description 11
- 230000007423 decrease Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000007246 mechanism Effects 0.000 description 6
- 230000004044 response Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 230000035807 sensation Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000010720 hydraulic oil Substances 0.000 description 1
Landscapes
- Power Steering Mechanism (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は回転式の油圧制御弁に関し、特に油圧式の動力
舵取装置（パワーステアリング）に適用するのに好適な
油圧制御弁に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary hydraulic control valve, and particularly to a hydraulic control valve suitable for application to a hydraulic power steering device (power steering).
油圧式の動力舵取装置は、舵輪操作に要する力を、舵取
機構中に配設した油圧シリンダが発生する油圧力により
補助するものであり、舵輪に連なり、舵輪操作に伴って
軸心回りに回動する入力軸と、舵取機構に連なり、その
軸心回りの回動に応じて舵取りがなされるようにした出
力軸とを、トーションバーを介して同軸上に連結し、舵
輪に操舵トルクが加えられた場合に、前記人力軸と出力
軸との間に、トーションバーの捩れに伴う相対角変位を
生せしめる一方、両輪の連結部分に回転式の油圧制御弁
を構成し、該油圧制御弁の動作により、前記相対角変位
の方向、即ち舵輪に加えられる操舵トルクの方向に応じ
て、前記油圧シリンダへの圧油の送給方向を切換え、該
油圧シリンダに操舵補助力を発生させるものである。A hydraulic power steering device uses hydraulic pressure generated by a hydraulic cylinder installed in the steering mechanism to assist the force required to operate the steering wheel. An input shaft that rotates around the steering mechanism and an output shaft that is connected to the steering mechanism and that performs steering according to the rotation around its axis are coaxially connected via a torsion bar, and the steering mechanism is connected to the steering wheel. When torque is applied, a relative angular displacement occurs between the human power shaft and the output shaft due to twisting of the torsion bar. By operating a control valve, the direction of supplying pressure oil to the hydraulic cylinder is changed according to the direction of the relative angular displacement, that is, the direction of the steering torque applied to the steering wheel, and a steering assist force is generated in the hydraulic cylinder. It is something.
この油圧制御弁は、前記入力軸又は出力軸のいずれか一
方の連結側端部近傍を弁体となし、その外周面に、軸長
方向に延びる長溝を周方向に等配をなして複数本形成す
ると共に、その内周面に、前記長溝と同数の軸長方向の
長溝を周方向に等配をなして形成してなる円筒状のケー
シングを、他方の連結側端部に同軸的に固設し、該ケー
シングに前記弁体を内嵌せしめ、夫々の長溝が千鳥配置
され、各長溝の幅方向両側に、相隣する長溝との等面積
の連通部が生じるように相互に位置決めし、更に、弁体
側の複数の長溝を、高圧源たる油圧ポンプと低圧源たる
油タンクとに交互に接続し、またケーシング側の複数の
長溝を、前記油圧シリンダの両袖室に交互に接続した構
成となっている。This hydraulic control valve has a valve body near the connecting end of either the input shaft or the output shaft, and has a plurality of long grooves equally spaced in the circumferential direction extending in the axial direction on the outer peripheral surface of the valve body. At the same time, a cylindrical casing having the same number of long grooves in the axial direction as the long grooves and equidistributed in the circumferential direction is formed on the inner circumferential surface thereof, and is coaxially fixed to the other connecting end. and the valve body is fitted into the casing, and the respective long grooves are arranged in a staggered manner, and mutually positioned so that communication portions of equal area with adjacent long grooves are formed on both sides in the width direction of each long groove, Furthermore, a plurality of long grooves on the valve body side are alternately connected to a hydraulic pump as a high pressure source and an oil tank as a low pressure source, and a plurality of long grooves on the casing side are alternately connected to both arm chambers of the hydraulic cylinder. It becomes.
この油圧制御弁の動作は、次のように行われる。The operation of this hydraulic control valve is performed as follows.
舵輪に操舵トルクが加えられた場合、前述した如く、入
力軸と出力軸の間、即ち油圧制御弁の弁体とケーシング
との間に、前記操舵トルクの方向への相対角変位が生じ
、油圧ポンプに接続された弁体の長溝両側の連通部の面
積は、一方が増大し他方が減少する。従って、連通面積
が増大する側に該長溝に相隣するケーシングの長溝内の
油圧が、同じく減少する側に相隣するケーシングの長溝
内の油圧よりも大となり、これらに夫々接続された前記
油圧シリンダの両袖室間に圧力差が生じ、該油圧シリン
ダが、前記操舵トルクの方向に対応する方向への操舵補
助力を発生するのである。When a steering torque is applied to the steering wheel, as described above, a relative angular displacement occurs between the input shaft and the output shaft, that is, between the valve body and the casing of the hydraulic control valve, in the direction of the steering torque, and the hydraulic pressure increases. The area of the communication portion on both sides of the long groove of the valve body connected to the pump increases on one side and decreases on the other side. Therefore, the hydraulic pressure in the long groove of the casing adjacent to the long groove on the side where the communication area increases becomes larger than the hydraulic pressure in the long groove of the casing adjacent to the long groove on the side where the communication area decreases, and the hydraulic pressure connected to these respective long grooves becomes larger. A pressure difference is generated between both arm chambers of the cylinder, and the hydraulic cylinder generates a steering assist force in a direction corresponding to the direction of the steering torque.
油圧式の動力舵取装置はこのような構成となっており、
操舵補助力の大きさは、前記油圧シリンダの両袖室間に
生じる圧力差に対応し、この圧力差は、油圧制御弁の前
記連通部における面積の大小に対応する。従って、舵輪
に加えられる操舵トルクの増加に対する操舵補助力の増
加態様は、油圧制御弁における弁体とケーシングとの間
の相対角変位の増大に対する前記連通部における面積の
変化態様に対応する。The hydraulic power steering device has this structure,
The magnitude of the steering assist force corresponds to the pressure difference generated between both arm chambers of the hydraulic cylinder, and this pressure difference corresponds to the size of the area of the communication portion of the hydraulic control valve. Therefore, the manner in which the steering assist force increases with respect to an increase in the steering torque applied to the steering wheel corresponds to the manner in which the area of the communication portion changes in response to an increase in the relative angular displacement between the valve body and the casing in the hydraulic control valve.
さて動力舵取装置においては、直進走行時における走行
安定性の向上のため、舵輪に適度の剛性を与えることが
要求され、逆に、停止時及び低速走行時においては、舵
輪操作に要する力を可及的に低減するため、大きい操舵
補助力の発生が要求される。従って、前記油圧シリンダ
が発生する操舵補助力は、操舵トルクの増加に応じて−
様な増加態様を示すのではなく、操舵トルクが小さい場
合には略Ｏに保たれ、所定量を超える操舵トルクに対し
てはこれの増加に応じて漸増し、更に大きい操舵トルク
に対してはこれの増加に応じて急増するような増加態様
を示すことが望ましく、このような増加態様は、油圧制
御弁の前記連通部における面積が、弁体とケーシングと
の間の相対角変位が所定値に達するまでは変化せず、そ
の後は相対角変位の増大に応じて略比例的に緩やかに変
化し、更に相対角変位が増大し、他の所定値に達した後
においては、これの増大に応じて急変するような変化態
様を示すことにより実現される。Now, in a power steering system, in order to improve running stability when driving straight, it is required to provide the steering wheel with an appropriate amount of rigidity, and conversely, when stopping or driving at low speed, the force required to operate the steering wheel is required to be given to the steering wheel. In order to reduce this as much as possible, it is required to generate a large steering assist force. Therefore, the steering assist force generated by the hydraulic cylinder changes as the steering torque increases.
Rather than showing a similar increasing pattern, when the steering torque is small, it is maintained at approximately O, and when the steering torque exceeds a predetermined amount, it gradually increases as the steering torque increases, and when the steering torque is even larger, the It is desirable that the area of the communication portion of the hydraulic control valve increases rapidly in response to an increase in this value. It does not change until it reaches , and after that it changes gradually in proportion to the increase in relative angular displacement, and after the relative angular displacement increases further and reaches another predetermined value, This is achieved by showing a sudden change in response to the change.
そこで、前記長溝の側壁と、ケーシングの内周面又は弁
体の外周面との間の角部に切欠部を形成して、前述の如
き連通面積の変化状態を実現した油圧制御弁がある。第
５図は、この油圧制御弁の一部を拡大して示す軸断面図
である。Therefore, there is a hydraulic control valve in which a notch is formed at the corner between the side wall of the long groove and the inner circumferential surface of the casing or the outer circumferential surface of the valve body to achieve the above-mentioned change in communication area. FIG. 5 is an enlarged axial sectional view of a part of this hydraulic control valve.
図において１はケーシング、２は弁体であり、ケーシン
グｌには、矩形断面をなし、軸長方向に延びる長溝５が
、また弁体２には、同様の長溝６が夫々形成してあり、
ケーシング１と弁体２とは、両者間に相対角変位が生じ
ていない場合に、前記長溝５，６が、夫々の幅方向両側
の等面積の連通部８，８を介して、相互に連通されるよ
うに周方向に位置決めされおり、図示しない舵輪に操舵
トルクが加えられ、両者間に相対角変位が生じた場合、
前記連通部８．８の面積が、一方は増大し他方が減少す
るようになっている。In the figure, 1 is a casing, 2 is a valve body, and the casing l has a long groove 5 that has a rectangular cross section and extends in the axial direction, and the valve body 2 has a similar long groove 6,
When there is no relative angular displacement between the casing 1 and the valve body 2, the long grooves 5 and 6 communicate with each other via communication portions 8 and 8 having equal areas on both sides in the width direction. When a steering torque is applied to a steering wheel (not shown) and a relative angular displacement occurs between the two,
The areas of the communicating portions 8.8 are increased on one side and decreased on the other side.
ケーシング１の内周面と前記長溝５の側壁との間の角部
には、前記連通部８．８の面積が、相対角変位の増大に
対して前述の如き変化態様を示すように、ケーシング１
の内周面に平行的な円弧又は直線であり、長溝５の側壁
に交わる第１の部分５０ａと、ケーシング１の内周面に
対し直角に近い角度を有して前記側壁側に傾斜する直線
であり、ケーシングｌの内周面に交わる第２の部分５０
ｂとからなる切欠部５０が形成されている。At the corner between the inner circumferential surface of the casing 1 and the side wall of the long groove 5, a casing is provided so that the area of the communicating portion 8.8 changes as described above with respect to an increase in relative angular displacement. 1
A first portion 50a that is a circular arc or a straight line parallel to the inner circumferential surface of the long groove 5 and intersects with the side wall of the long groove 5, and a straight line that is inclined toward the side wall at an angle close to a right angle to the inner circumferential surface of the casing 1. and a second portion 50 that intersects with the inner circumferential surface of the casing l
A notch 50 consisting of b is formed.
第６図は、この切欠部５０の作用の説明図である。FIG. 6 is an explanatory diagram of the function of this notch 50.
切欠部５０を形成してなる油圧制御弁においては、ケー
シングＩと弁体２との間に生しる相対角変位により、本
図に破線にて示す如く、弁体２の外周面と長溝６の側壁
との間の角部が、前記長溝５の側壁と周方向に一致する
までの間においては、連通部８の面積は変化せず、その
後、前記角部が、同じく一点鎖線にて示す位置に達する
までの間においては、連通部８０面積は、第１の部分５
０ａにおける半径方向の深さ寸法すに支配され、該部分
５０ａが弁体２の外周面に平行的であることから、相対
角変位の増大に応じて漸減し、更に大きい相対角変位が
生じた場合、連通部８の面積は、第２の部分５０ｂのケ
ーシング１の内周面との交叉部と、前記角部との間にお
ける周方向の離隔距離Ｓに支配されるから、相対角変位
の増大に応じて急減し、連通面積の所望の変化状態が実
現される。In the hydraulic control valve formed with the notch 50, due to the relative angular displacement that occurs between the casing I and the valve body 2, the outer peripheral surface of the valve body 2 and the long groove 6 are separated from each other, as shown by the broken line in this figure. The area of the communicating portion 8 does not change until the corner between the long groove 5 and the side wall of the long groove 5 coincides with the side wall of the long groove 5 in the circumferential direction. Until reaching the position, the area of the communication portion 80 is equal to that of the first portion 5.
Since the portion 50a is parallel to the outer peripheral surface of the valve body 2, it gradually decreases as the relative angular displacement increases, and an even larger relative angular displacement occurs. In this case, the area of the communication portion 8 is governed by the circumferential separation distance S between the intersection of the second portion 50b with the inner circumferential surface of the casing 1 and the corner, so that the relative angular displacement is It rapidly decreases as it increases, and the desired state of change in communication area is achieved.
さて、ケーシング１と弁体２との間に生じている相対角
変位が大きく、前記第１の部分５０ａと弁体２の外周面
との重なり部分の長さｌが長い場合、切欠部５０を通過
し、例えば長溝６がら長溝５に向かう圧油の流れは、第
６図に矢符にて示す如く生じ、圧油は、互いに略平行を
なして対向する切欠部５０の第１の部分５０ａと弁体２
の外周面との間を流れるから、切欠部５０における圧油
の通流ＩＱ（ｃｍ’ ／ｓｅｃ ）は、平行２面間を流
れる非圧縮性流体の流量を示す公知の次式にて近偵的に
求めることができる。Now, when the relative angular displacement occurring between the casing 1 and the valve body 2 is large and the length l of the overlapping portion between the first portion 50a and the outer circumferential surface of the valve body 2 is long, the cutout portion 50 is A flow of pressure oil from the long groove 6 toward the long groove 5 occurs as shown by arrows in FIG. and valve body 2
Since the pressure oil flows between the outer peripheral surface of It can be found exactly.
１２・ν・Ｔ−β
但し、式中の各符号は、
Ｐｌ ；長溝６内の圧力（ｋｇ／ｃｍ２）Ｐｚ ；長溝
５内の圧力（ｋｇ／ｃｍ２）ｂ ；切欠部５０の深さ寸
法（ｃｍ）
Ｗ ；ケーシング１の軸長方向における切欠部５０の形
成長さ（ｃｍ）
ｇ ；重力の加速度（ｃｍ／ ５ｅｃ２）ν ：油の動
粘性係数（ｃｍ” ／ｓｅｅ ）γ ；油の比重量Ｃｋ
ｇ／ｃｍ３）
ｌ ；重なり部分の長さ（ｃｍ）
を夫々示す。12・ν・T−β However, each symbol in the formula is as follows: Pl; Pressure in the long groove 6 (kg/cm2) Pz; Pressure in the long groove 5 (kg/cm2) b; Depth dimension of the notch 50 ( cm) W: Shape growth of the notch 50 in the axial direction of the casing 1 (cm) g: Acceleration of gravity (cm/5ec2) ν: Kinematic viscosity coefficient of the oil (cm”/see) γ: Specific weight of the oil Ck
g/cm3) l: Indicates the length (cm) of the overlapping portion.
この式には、温度に応じて大きく変動する値である動粘
性係数νが含まれているために、該弐により求められる
圧油の通流ｉＱは、油温の高低に応じて異なる。従って
、該切欠部５０を備えた油圧制御弁を用いてなる従来の
動力舵取装置においては、操舵トルクの増加に対する操
舵補助力の増加特性が、油温の高低に応じて異なること
になり、油温の高低による操舵感覚の差異が生じるとい
う難点があり、例えば、運転開始直後等、油温か低い時
点における操舵感覚と、所定時間の運転を行い油温が十
分に上昇した後における操舵感覚との間に差異が生じる
結果、運転者に違和感を与えるという難点があった。Since this equation includes the kinematic viscosity coefficient ν, which is a value that fluctuates greatly depending on the temperature, the pressure oil flow iQ determined by this equation differs depending on the oil temperature. Therefore, in the conventional power steering system using a hydraulic control valve equipped with the notch 50, the increase characteristic of the steering assist force with respect to the increase in the steering torque differs depending on the oil temperature. There is a problem in that the steering sensation differs depending on the oil temperature.For example, the steering sensation when the oil temperature is low, such as immediately after the start of operation, and the steering sensation after the oil temperature has risen sufficiently after driving for a predetermined period of time are different. As a result of the difference between the two, there was a problem in that it gave the driver a sense of discomfort.
本発明は斯かる事情に鑑みてなされたものであり、油温
の影響を受けることなく、常時一定の操舵感覚が得られ
、しかも、前述の如き操舵補助力の増加特性を損なうこ
とのない油圧制御弁を提供することを目的とする。The present invention has been made in view of the above circumstances, and provides a hydraulic pressure that allows a constant steering feeling to be obtained at all times without being affected by oil temperature, and that does not impair the above-mentioned characteristic of increasing steering assist force. The purpose is to provide a control valve.
本発明に係る油圧制御弁は、高圧源と低圧源とに交互に
連通す為複数本の長溝をその外周面に等配してある円筒
状の弁体を、相異なる圧油の送給先に交互に連通し、前
記長溝と同数の長溝をその内周面に等配してある筒状の
ケーシングに、相対回動自在に内嵌してなり、この相対
回動に伴って前記両長溝間に生じる連通面積の変化に応
じて、前記送給先への送給油圧を制御する油圧制御弁に
おいて、前記長溝の側壁と、前記ケーシングの内周面又
は弁体の外周面との間の角部に、前記内周面又は外周面
に平行的であり、前記側壁に連なる第１の部分、及び前
記内周面又は外周面からの半径方向の深さ寸法が、前記
第１の部分のそれよりも大なる部分を含み、前記内周面
又は外周面に直角に近い角度をなして連なる第２の部分
とを備えた切欠部が形成してあり、前記第１の部分の周
方向長さが、該部分における前記深さ寸法、及び前記両
長溝間に生じる圧力差に関連して定まる所定長さ以下と
してあることを特徴とする。The hydraulic control valve according to the present invention has a cylindrical valve body having a plurality of long grooves evenly distributed on its outer circumferential surface in order to alternately communicate with a high pressure source and a low pressure source. It is fitted into a cylindrical casing in which the same number of long grooves as the long grooves are equally distributed on the inner circumferential surface of the casing so as to be relatively rotatable, and with this relative rotation, both the long grooves In the hydraulic control valve that controls the hydraulic pressure supplied to the destination according to a change in the communication area occurring between the side wall of the long groove and the inner circumferential surface of the casing or the outer circumferential surface of the valve body. a first portion that is parallel to the inner circumferential surface or the outer circumferential surface and continuous to the side wall; and a radial depth dimension from the inner circumferential surface or the outer circumferential surface of the first portion; A notch is formed that includes a second portion that is larger than the second portion and is continuous at an angle close to a right angle to the inner circumferential surface or the outer circumferential surface, and the circumferential length of the first portion is The groove is characterized in that the length is equal to or less than a predetermined length determined in relation to the depth dimension in the portion and the pressure difference generated between the two long grooves.
本発明においては、前記第１の部分の周方向長さを、前
記所定長さ以下とし、該部分と、弁体の外周面又はケー
シングの内周面との間に、前記所定長さを超える平行的
な重なり部分が生じないようにして、切欠部における圧
油の通流量に、油温により生じる影響を緩和する。In the present invention, the circumferential length of the first portion is equal to or less than the predetermined length, and the distance between the first portion and the outer circumferential surface of the valve body or the inner circumferential surface of the casing exceeds the predetermined length. By preventing parallel overlapping portions from occurring, the influence of oil temperature on the flow rate of pressure oil in the notch is alleviated.
以下本発明をその実施例を示す図面に基づいて詳述する
。第１図は動力舵取装置の油圧回路図と共に示す本発明
に係る油圧制御弁の正面断面図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is a front sectional view of a hydraulic control valve according to the present invention, shown together with a hydraulic circuit diagram of a power steering device.
本発明に係る油圧制御弁は、円筒状をなすケーシング１
と、これの内径に略等しい外径を有し、ケーシング１に
同軸回動自在に内嵌された円筒状の弁体２とを備えてお
り、動力舵取装置に適用する場合、その上端部に同軸的
に固設された舵輪の回動操作に伴って軸心回りに回動す
る図示しない入力軸の下部に弁体２を構成する一方、そ
の下端部を舵取機構に連結され、その回転により舵取機
構を動作させるべくなした出力軸の上端部にケーシング
１を同軸的に固設し、前記入力軸と出力軸とをトーショ
ンバー４を介して同軸的に連結すると共に、この連結部
においてケーシングｌに弁体２を内嵌せしめ、該ケーシ
ングｌの外周を、車体の適宜位置に固定され、前記両輪
の外側を囲繞する筒形のハウジング３内に回動自在に支
承せしめて構成される。而して、前記トーションバー４
は、図示の如く弁体２の軸心上に位置し、舵輪の回動操
作に伴って該トーションバー４に生じる捩れに応じて、
ケーシング１と弁体２との間に相対角変位が生じるよう
になっている。The hydraulic control valve according to the present invention has a cylindrical casing 1
and a cylindrical valve body 2 which has an outer diameter approximately equal to the inner diameter of the valve body 2 and is coaxially rotatably fitted into the casing 1. When applied to a power steering device, the upper end portion The valve body 2 is constructed at the lower part of an input shaft (not shown) that rotates about its axis in response to the rotation operation of a steering wheel coaxially fixed to the steering wheel. A casing 1 is coaxially fixed to the upper end of an output shaft which operates a steering mechanism by rotation, and the input shaft and output shaft are coaxially connected via a torsion bar 4, and this connection is A valve body 2 is fitted into a casing l at a portion, and the outer periphery of the casing l is rotatably supported within a cylindrical housing 3 which is fixed at an appropriate position on the vehicle body and surrounds the outsides of the two wheels. be done. Therefore, the torsion bar 4
is located on the axis of the valve body 2 as shown in the figure, and according to the twisting that occurs in the torsion bar 4 as the steering wheel rotates,
A relative angular displacement occurs between the casing 1 and the valve body 2.
ケーシング１の内周面及び弁体２の外周面には、軸長方
向を長平方向とし、矩形断面を有する８木の長溝５，５
・・・、及び同じく８本の長溝６，６・・・が、周方向
に等配をなして夫々形成してあり、ケーシング１と弁体
２とは、トーションバー４に捩りが生じていない状態（
中立状態）において、第１図に示す如く、長溝５，５・
・・と長溝６，６・・・とが千鳥配置され、これらが幅
方向両側の等面積の連通部８．８ （第２図参照）を介
して相互に連通ずるように、周方向に位置決めされてい
る。The inner peripheral surface of the casing 1 and the outer peripheral surface of the valve body 2 are provided with eight long grooves 5, 5 having a rectangular cross section, with the axial direction being the elongated direction.
. . . and eight long grooves 6, 6 . situation(
(neutral state), as shown in FIG.
... and long grooves 6, 6... are arranged in a staggered manner, and are positioned in the circumferential direction so that they communicate with each other via communication portions 8.8 (see Fig. 2) with equal areas on both sides in the width direction. has been done.
弁体２の長溝６，６・・・は、これらの幅に等しい幅と
適宜の外径とを有し、弁体２の軸心に直交する軸回りに
回転する回転砥石を用い、これを弁体２の外周に当接せ
しめた後、該回転砥石に弁体２の軸心に向かう方向への
送りを与えることにより、軸長方向に適宜の長手寸法を
有して形成され、また、ケーシング１の長溝５，５・・
・は、ケーシング１の仕上げ内径に等しい円形の外周に
長溝５の形状に対応する８個所の凸部を有するブローチ
を用い、これをケーシング１の内部に挿通せしめること
により、ケーシング１の内面仕上と同時的に形成される
。The long grooves 6, 6... of the valve body 2 have a width equal to these widths and an appropriate outer diameter, and are polished using a rotary grindstone that rotates around an axis perpendicular to the axis of the valve body 2. After being brought into contact with the outer periphery of the valve body 2, the rotary grindstone is fed in a direction toward the axis of the valve body 2, so that it is formed with an appropriate longitudinal dimension in the axial direction, and Long grooves 5, 5 of casing 1...
- By using a broach that has eight convex portions corresponding to the shape of the long groove 5 on the circular outer circumference that is equal to the finished inner diameter of the casing 1, and inserting this broach into the inside of the casing 1, the inner surface finish of the casing 1 can be improved. formed simultaneously.
ケーシング１の外周面には、これの全周に亘る３本の環
状溝７，７．７ （、中央の一部のみ図示）が、軸長方
向に相互に適長離隔させて形成してあり、中央の環状溝
７は、油圧ポンプＰに接続され、両側の環状溝７，７は
、舵取機構の一部に構成された操舵補助用の油圧シリン
ダＳの両袖室Ｓｌ＋Ｓ！に夫々接続してある。そして、
ケーシング１の長溝５，５・・・の内、１つ置きに位置
する４本の長溝５，５・・・は、゛ケーシング１を半径
方向に貫通する態様にて形成された第１の油導出孔１１
．１１・・・により、両側に位置する環状溝７，７の一
方に、また他の４本の長溝５，５・・・は、同様に形成
された第２の油導出孔１２．１２・・・により、前記環
状溝７゜７の他方に夫々連通させである。更に弁体２の
長溝６．６・・・の内、１つ置きに位置する４木の長溝
６．６・・・は、ケーシング１を半径方向に貫通する態
様にて形成され、これら夫々の外側に開口する油導入孔
１０．１０・・・により、中央の環状溝７に連通させて
あり、また他の４本の長溝６．６・・・は、弁体２を半
径方向に貫通する戻り油孔１３により、弁体２の中抜き
部２０に連通させである。この中抜き部２０は、戻り油
路としての作用をなすものであり、低圧状態に維持され
た油タンクＴに接続されている。On the outer peripheral surface of the casing 1, three annular grooves 7, 7.7 (only a part of the center part is shown) are formed along the entire circumference of the casing 1 and are spaced apart from each other by an appropriate length in the axial direction. , the annular groove 7 in the center is connected to the hydraulic pump P, and the annular grooves 7, 7 on both sides are the arm chambers Sl+S! of a hydraulic cylinder S for steering assistance, which is configured as a part of the steering mechanism. are connected to each. and,
Among the long grooves 5, 5... of the casing 1, the four long grooves 5, 5... located at every other place are used for the first oil grooves formed in a manner that penetrates the casing 1 in the radial direction. Outlet hole 11
．． 11..., one of the annular grooves 7, 7 located on both sides, and the other four long grooves 5, 5... are similarly formed second oil outlet holes 12, 12...・They are connected to the other of the annular grooves 7 and 7, respectively. Further, among the long grooves 6.6 of the valve body 2, the four long grooves 6.6 located at every other place are formed in such a manner that they penetrate the casing 1 in the radial direction. The oil introduction holes 10, 10, . The return oil hole 13 communicates with the hollow portion 20 of the valve body 2 . This hollow portion 20 functions as a return oil path and is connected to an oil tank T maintained at a low pressure state.
即ち、ケーシング１の長？ｖＦ５，５・・・は、油導出
孔１１及び環状溝７、又は油導出孔１２及び環状溝７を
夫々介して、油圧ポンプＰが発生する圧油あ相異なる送
給先である前記油室Ｓｌ、又は同Ｓ２に交互に連通され
ており、また弁体２の長溝６，６・・・は、油導入孔１
０及び環状溝７、又は戻り油孔１３及び中抜き部２０を
介して、高圧源たる油圧ポンプＰ又は低圧源たる油タン
クＴに交互に連通されている。従って、油ポンプＰが発
生する圧油は、中央の環状溝７及び油導入孔１０を介し
て弁体２の長？Ｒ６に導入され、該長溝６の幅方向両側
の連通部８．８を通過して、これの両側に相隣するケー
シングの長溝５，５内に導入され、次いで、これらの長
溝５，５における前記長溝６と反対側の連通部８を通過
して、油タンクＴに接続された長溝６゜６内に導入され
、戻り油孔１３及び中抜き部２０を介して油タンクＴに
還流する。長溝６両側の連通部８．８の面積が等しい場
合、即ち、舵輪に操舵トルクが加えられておらず、ケー
シング１と弁体２との位置関係が前記中立状態にある場
合、前記長溝６の両側に相隣する長溝５，５間には圧力
差が発生せず、これらに油導出孔１１．１２を介して夫
々連通する油圧シリンダＳの両袖室Ｓ、、Ｓ、内の圧力
は等しく、該油圧シリンダＳは操舵補助力を発生しない
一方ミ舵輪に操舵トルクが加えられ、ケーシング１と弁
体２との間に相対角変位が生じた場合、前記連通部８，
８の面積は一方が増加し他方が減少する結果、前者を介
して前記長溝６に連通する長溝５内部の圧力が、後者を
介して前記長溝６に連通する長溝５内部の圧力よりも大
となり、これらに夫々連通する油室Ｓｌ、ＳＺ間に、両
長溝５，５間に生じる圧力差、即ち、前記操舵トルクの
方向及び大きさに対応する圧力差が生じ、油圧シリンダ
Ｓは、この圧力差に相当する操舵補助力を発生する。That is, the length of casing 1? vF5, 5... are the oil chambers, which are different destinations, of the pressure oil generated by the hydraulic pump P via the oil outlet hole 11 and the annular groove 7, or the oil outlet hole 12 and the annular groove 7, respectively. The long grooves 6, 6, . . . of the valve body 2 are alternately connected to the oil introduction hole 1.
0 and the annular groove 7, or the return oil hole 13 and the hollow part 20, they are alternately communicated with a hydraulic pump P, which is a high pressure source, or an oil tank T, which is a low pressure source. Therefore, the pressure oil generated by the oil pump P flows through the central annular groove 7 and the oil introduction hole 10 through the length of the valve body 2. R6, passes through the communication portions 8.8 on both sides of the long groove 6 in the width direction, and is introduced into the long grooves 5, 5 of the casing adjacent to each other on both sides of this, and then in these long grooves 5, 5. The oil passes through the communication portion 8 on the opposite side of the long groove 6, is introduced into the long groove 6°6 connected to the oil tank T, and returns to the oil tank T via the return oil hole 13 and the hollow portion 20. When the areas of the communication portions 8.8 on both sides of the long groove 6 are equal, that is, when no steering torque is applied to the steering wheel and the positional relationship between the casing 1 and the valve body 2 is in the neutral state, the long groove 6 has the same area. No pressure difference occurs between the long grooves 5, 5 adjacent to each other on both sides, and the pressures in both sleeve chambers S, S, of the hydraulic cylinder S, which communicate with these through the oil outlet holes 11 and 12, are equal. , the hydraulic cylinder S does not generate a steering assist force, but when a steering torque is applied to the steered wheels and a relative angular displacement occurs between the casing 1 and the valve body 2, the communication portion 8,
As a result, the pressure inside the long groove 5 communicating with the long groove 6 through the former is greater than the pressure inside the long groove 5 communicating with the long groove 6 through the latter. , and between the oil chambers Sl and SZ communicating with these, there is a pressure difference between both the long grooves 5, 5, that is, a pressure difference corresponding to the direction and magnitude of the steering torque, and the hydraulic cylinder S A steering assist force corresponding to the difference is generated.
動力舵取装置において、油圧シリンダＳが発生する操舵
補助力の操舵トルクの増加に対する望ましい増加特性は
、前述した如く、操舵トルクが小さい場合には、操舵補
助力は略Ｏに保たれ、その後は、操舵トルクの増加に対
して比例的に漸増する操舵補助力が得られ、更に前記所
定値よりも大きい他の所定値を超えた後には、操舵トル
クの増加に対して急増する操舵補助力が得られるもので
あり、このような特性は、前記連通部８．８・・・にお
ける連通面積が、ケーシングｌと弁体２との相対角変位
が小さい間には、該相対角変位の増大に対して緩やかに
夏化し、相対角変位が所定値を超えた後に急激に変化す
ることにより実現される。In the power steering system, the desirable increase characteristic of the steering assist force generated by the hydraulic cylinder S with respect to the increase in steering torque is that, as described above, when the steering torque is small, the steering assist force is maintained at approximately O; , a steering assist force that gradually increases in proportion to an increase in steering torque is obtained, and furthermore, after another predetermined value greater than the predetermined value is exceeded, a steering assist force that rapidly increases in response to an increase in steering torque is obtained. These characteristics are such that, while the relative angular displacement between the casing l and the valve body 2 is small, the communication area in the communicating portions 8, 8, . . . On the other hand, this is realized by gradual summerization and a sudden change after the relative angular displacement exceeds a predetermined value.
本発明に係る油圧制御弁においては、ケーシング１の内
周面と、長溝５の側壁との間の角部、又は弁体２の外周
面と長溝６の側壁との間の角部に第２図に示す如き切欠
部９を形成することにより、連通部８．８における前述
の如き面積の変化状態を実現し、しかも操舵補助力の増
加特性に温度変化が与える影響を解消又は緩和する。In the hydraulic control valve according to the present invention, a second By forming the notch 9 as shown in the figure, the above-mentioned area change state in the communication portion 8.8 is realized, and the influence of temperature change on the increase characteristic of the steering assist force is eliminated or alleviated.
第２図及び第３図は、切欠部９の形成態様を示す第１図
の一部拡大図であり、第４図は、第２図に示す切欠部９
の作用の説明図である。これらの図においては、ケーシ
ングｌの内周面と長溝５の側壁との間の角部に切欠部９
が形成されているが、弁体２の外周面と長溝６の側壁と
の間の角部に形成してもよいことは言うまでもない。ま
た、第１図に示すように、前記角部は、夫々の長溝５又
は長溝６の両側に各２個、合計１６個存在するが、切欠
部９は、これ゛らの全てに形成してもよく、一部のみに
形成してもよい。2 and 3 are partially enlarged views of FIG. 1 showing how the notch 9 is formed, and FIG. 4 is a partially enlarged view of the notch 9 shown in FIG.
FIG. In these figures, there is a notch 9 at the corner between the inner peripheral surface of the casing l and the side wall of the long groove 5.
, but it goes without saying that it may be formed at the corner between the outer circumferential surface of the valve body 2 and the side wall of the long groove 6. Further, as shown in FIG. 1, there are 16 corners in total, two on each side of each long groove 5 or 6, but the notch 9 is formed in all of these corners. It may also be formed only in part.
切欠部９は、ケーシング１の内周面に平行的な直線又は
円弧であり、長溝５の側壁の中途部に連なり、周方向に
所定の長さしを有すると共に、半径方向にｂなる深さを
有する第１の部分９ａと、半径方向に前記すよりも大き
い深さＢを有する部分を含み、ケーシング１の内周面に
、直角に近い交叉角を有して連なる第２の部分９ｂとを
備えたものである。The notch 9 is a straight line or an arc parallel to the inner circumferential surface of the casing 1, is continuous to the middle part of the side wall of the long groove 5, has a predetermined length in the circumferential direction, and has a depth b in the radial direction. a first portion 9a having a depth B in the radial direction, and a second portion 9b that includes a portion having a depth B greater than the above in the radial direction and is continuous with the inner circumferential surface of the casing 1 at an intersecting angle close to a right angle. It is equipped with the following.
第２図に示す第２の部分９ｂは、２個の円弧の組合せに
より構成されており、第３図に示す第２の部分は、３本
の直線の組合せにより構成されているが、第２の部分９
ｂは、例えば、−個の円弧、円弧及び直線の組合せ、又
は適宜の曲線の組合せ等、いかなる構成であってもよい
。The second portion 9b shown in FIG. 2 is made up of a combination of two circular arcs, and the second portion 9b shown in FIG. 3 is made up of a combination of three straight lines. Part 9
b may have any configuration, such as - circular arcs, a combination of circular arcs and straight lines, or a combination of appropriate curves.
この切欠部９の作用について第４図に基づいて説明する
。舵輪に加えられる操舵トルクにより、トーションバー
４に捩れが生じ、ケーシング１と弁体２との間に相対角
変位が生じた場合、弁体２の外周面と長溝６の側壁との
間の角部は、ケーシング１に対して周方向に相対移動す
る。この相対移動により、前艷角部が、図中に破線にて
示す位置に達し、長溝５の側壁と周方向に一致した後、
図中に一点鎖線にて示す位置に達し、切欠部９における
第２の部分９ｂとケーシング１の内周面との交叉部と、
前記角部との間の周方向の離隔距ｉｔ ｓが、第１の部
分９ａの深さ寸法すに略等しくなるまでの間においては
、連通部８の面積は前記深さ寸法すに支配され、第１の
部分９ａがケーシング１の外周面に平行的であるから、
連通部８の面積は、前記相対移動量の増加、即ちケーシ
ング１と弁体２との間の相対角変位の増加に応じて漸減
し、−方、前記角部の相対移動が一点鎖線にて示す位置
を超えて生じた場合、連通部８の面積は、前記離隔距離
Ｓの変化状態に対応する変化状態を示し、ケーシング１
と弁体２の相対角変位の増加に応じて急減し、連通面積
の所望の変化状態が実現される。The function of this notch 9 will be explained based on FIG. 4. When the torsion bar 4 is twisted by the steering torque applied to the steering wheel and a relative angular displacement occurs between the casing 1 and the valve body 2, the angle between the outer peripheral surface of the valve body 2 and the side wall of the long groove 6 The portion moves relative to the casing 1 in the circumferential direction. Due to this relative movement, the forebrake corner reaches the position shown by the broken line in the figure and coincides with the side wall of the long groove 5 in the circumferential direction.
Reaching the position indicated by the dashed line in the figure, the intersection of the second portion 9b of the notch 9 and the inner circumferential surface of the casing 1;
Until the circumferential distance it s from the corner becomes substantially equal to the depth of the first portion 9a, the area of the communication portion 8 is dominated by the depth. , since the first portion 9a is parallel to the outer peripheral surface of the casing 1,
The area of the communication portion 8 gradually decreases as the relative movement increases, that is, as the relative angular displacement between the casing 1 and the valve body 2 increases. If the area of the communication portion 8 occurs beyond the indicated position, the area of the communication portion 8 shows a change state corresponding to the change state of the separation distance S, and the casing 1
and decreases rapidly as the relative angular displacement of the valve body 2 increases, and a desired state of change in the communication area is achieved.
また、前記切欠部９においては、これと弁体２の外周面
との重なり部分の周方向の長さは、前記相対角変位が大
きい場合においても、前記第１の部分９ａの周方向長さ
しを超えることはない。例えば、長溝６から長溝５へ向
かう圧油は、第４図に矢符にて示すように、まず第２の
部分９ｂ内に流入し、第１の部分９ａと弁体２の外周面
との間を通過して長溝５に流入する。即ち第１の部分９
ａは、長さしの絞り部として作用し、Ｌを十分小さくし
た場合、切欠部９における圧油の通流量Ｑ （ｃｍ’
／ｓｅｃ ）は、絞り部を通過する非圧縮性流体の流量
を示す公知の次式にて求められる。Further, in the notch 9, the circumferential length of the overlapping portion with the outer peripheral surface of the valve body 2 is the same as the circumferential length of the first portion 9a even when the relative angular displacement is large. It will never exceed. For example, the pressure oil flowing from the long groove 6 to the long groove 5 first flows into the second portion 9b, as shown by the arrow in FIG. It passes through the gap and flows into the long groove 5. i.e. the first part 9
a acts as a length constriction, and if L is made sufficiently small, the flow rate of pressure oil in the notch 9 Q (cm'
/sec) is determined by the following well-known formula that indicates the flow rate of the incompressible fluid passing through the constriction section.
Ｑ＝α・Ｆ・ ２ｇ−Ｐ＋ −Ｐｚ γ ・・・（
２）但し、αは絞り部における流量係数であり、また、
Ｆは絞り部の面積（ｃｍ” ）であって、他の符号は（
１１式におけるものと同様である。切欠部９における流
れにおいては、絞り部の面積Ｆが次式にて算出できるこ
とは明らかである。Q=α・F・2g−P+ −Pz γ ...(
2) However, α is the flow coefficient at the throttle part, and
F is the area of the aperture (cm”), and the other symbols are (
This is the same as in formula 11. It is clear that for the flow in the notch 9, the area F of the constriction can be calculated using the following equation.
Ｆ＝ｂ−ｗ ・・・（３）
但し、Ｗはケーシング１の軸長方向への切欠部９の形成
長さ（ｃｍ）である。F=b-w (3) where W is the shape growth (cm) of the notch 9 in the axial direction of the casing 1.
前記周方向長さしが大きい場合、前記通流量Ｑは、前述
した（１１式のｌをＬにて置換して得られる次式にて求
め６れる。When the circumferential length is large, the flow rate Q can be calculated using the following equation (obtained by replacing l in equation 11 with L) as described above.
１２・ ν ・ Ｔ ・ Ｌ
（２）式により求められるＱと、（４）式により求めら
れるＱとを等しいとして得られるＬをＬ ｍａｘとする
と、
ｈ！
となる。12・ν・T・L If Q obtained by equation (2) and Q obtained by equation (4) are equal and L obtained is L max, then h! becomes.
但し、ΔＰ−（Ｐ＋ Ｐｚ）である。However, ΔP-(P+Pz).
従って、切欠部９の第１の部分９ａの周方向長さＬを、
（５）式にて算出されるＬｍａｘ以下とすることにより
、切欠部９における圧油の通流量Ｑは、温度に応じて大
きく変動する動粘性係数νを含まない前記（２）式にて
求められることになり、油温の高低が切欠部９における
通流量に与える影響は小さく、本発明に係る油圧制御弁
においては、操舵補助力の増加特性が、油温の高低に影
響されることはない。Therefore, the circumferential length L of the first portion 9a of the notch 9 is
By setting Lmax to be equal to or less than Lmax calculated using equation (5), the flow rate Q of pressure oil in the notch 9 can be calculated using equation (2) above, which does not include the kinematic viscosity coefficient ν, which varies greatly depending on the temperature. Therefore, the influence of the oil temperature on the flow rate in the notch 9 is small, and in the hydraulic control valve according to the present invention, the increase characteristic of the steering assist force is not affected by the oil temperature. do not have.
動力舵取装置における作動油の温度は、通常６０℃程度
まで上昇する。従って、６０℃における油の動粘性係数
νに０．１０ （ｃｍ” ／ｓｅｃ ） 、同じ（油の
比重ｉ１ ｒ ｙ８．６７ｘｌｏ−’ （ｋｇ／ｃｍ”
） 、及び流量係数α＝０．７の各値を（５）式に代
入すると、Ｌｍａｘ Ｑｌｌ ９．０Ｘ１０” ・ｂ
２・Ｆ■丁−＜６］となり、例えば、第１の部分９ａの
深さ寸法すが０．００５ ｃｍであり、長溝５．６間に
生じる圧力差ΔＰが、最大２０ｋｇ／ｃｍ”である場合
、これらを（６）式に代入すると、Ｌｍａｘ ｋｏ、１
０１ ｃｍとなり、第１の部分９ａの周方向長さしを０
．１０１ ｃｍ以下とすることにより、油温の高低が操
舵補助力の増加特性に与える影響を、緩和することがで
きる。The temperature of the hydraulic oil in the power steering device usually rises to about 60°C. Therefore, the kinematic viscosity coefficient ν of oil at 60°C is 0.10 (cm"/sec), which is the same (specific gravity of oil i1 ry8.67xlo-'(kg/cm"
) and flow rate coefficient α=0.7 into equation (5), Lmax Qll 9.0X10”・b
For example, the depth dimension of the first portion 9a is 0.005 cm, and the pressure difference ΔP occurring between the long grooves 5.6 is 20 kg/cm at maximum. , by substituting these into equation (6), Lmax ko, 1
01 cm, and the circumferential length of the first portion 9a is 0.
．． By setting it to 101 cm or less, it is possible to alleviate the influence of oil temperature on the increase characteristic of the steering assist force.
以上詳述した如く、本発明に係る油圧制御弁においては
、切欠部における圧油の通流量が、油温の影響を受けて
変化することがないから、これを動力舵取装置に適用し
た場合、操舵トルクの増加に対する操舵補助力の増加特
性が油温の高低に影響されることがな（、常時一定の操
舵感覚が得られる上、前記増加特性を、動力舵取装置に
要求される所望の特性とすることが可能である等、本発
明は優れた効果を奏する。As detailed above, in the hydraulic control valve according to the present invention, the flow rate of pressure oil in the notch does not change due to the influence of oil temperature, so when this is applied to a power steering device In addition, the increasing characteristic of the steering assist force with respect to the increase in steering torque is not affected by the oil temperature. The present invention has excellent effects, such as being able to achieve the following characteristics.
第１図は動力舵取装置の油圧回路図と共に示す本発明に
係る油圧制御弁の正面断面図、第２図及び第３図は切欠
部の形成状態を示す第１図の一部拡大図、第４図は切欠
部の作用を説明するための図、第５図は従来の油圧制御
弁における切欠部の形成状態を示す図、第６図は従来の
切欠部の作用を説明するための図である。
■・・・ケーシング ２・・・弁体 ４・・・トー
ションバー ５，６・・・長溝 ９・・・切欠部９
ａ・・・第１の部分 ９ｂ・・・第２の部分 １０
・・・油導入孔 ｌＬ１２・・・油導出孔 Ｐ・・・
油圧ポンプＳ・・・油圧シリンダ
特 許 出願人 光洋精工株式会社
代理人 弁理士 河 野 登 夫
第２図
第４図
第３図
簗６図FIG. 1 is a front cross-sectional view of a hydraulic control valve according to the present invention shown together with a hydraulic circuit diagram of a power steering device; FIGS. 2 and 3 are partially enlarged views of FIG. 1 showing how the notch is formed; Fig. 4 is a diagram for explaining the action of the notch, Fig. 5 is a diagram showing how the notch is formed in a conventional hydraulic control valve, and Fig. 6 is a diagram for explaining the action of the conventional notch. It is. ■...Casing 2...Valve body 4...Torsion bar 5, 6...Long groove 9...Notch 9
a...First part 9b...Second part 10
...Oil introduction hole lL12...Oil outlet hole P...
Hydraulic pump S...Hydraulic cylinder patent Applicant Koyo Seiko Co., Ltd. Representative Patent attorney Noboru Kono Figure 2 Figure 4 Figure 3 Figure 6
Claims (1)
その外周面に等配してある円筒状の弁体を、相異なる圧
油の送給先に交互に連通し、前記長溝と同数の長溝をそ
の内周面に等配してある筒状のケーシングに、相対回動
自在に内嵌してなり、この相対回動に伴って前記両長溝
間に生じる連通面積の変化に応じて、前記送給先への送
給油圧を制御する油圧制御弁において、 前記長溝の側壁と、前記ケーシングの内周面又は弁体の
外周面との間の角部に、前記内周面又は外周面に平行的
であり、前記側壁に連なる第１の部分、及び前記内周面
又は外周面からの半径方向の深さ寸法が、前記第１の部
分のそれよりも大なる部分を含み、前記内周面又は外周
面に直角に近い交叉角をなして連なる第２の部分とを備
えた切欠部が形成してあり、 前記第１の部分の周方向長さが、該部分における前記深
さ寸法、及び前記両長溝間に生じる圧力差に関連して定
まる所定長さ以下としてあることを特徴とする油圧制御
弁。[Scope of Claims] 1. A cylindrical valve body having a plurality of long grooves evenly distributed on its outer circumferential surface that alternately communicates with a high pressure source and a low pressure source is used to alternately supply different pressure oils to different destinations. It is fitted into a cylindrical casing in which the same number of long grooves as the long grooves are equally distributed on the inner circumferential surface of the casing so as to be relatively rotatable. In a hydraulic control valve that controls the hydraulic pressure supplied to the destination according to a change in the communication area that occurs, the corner between the side wall of the long groove and the inner circumferential surface of the casing or the outer circumferential surface of the valve body. a first portion that is parallel to the inner circumferential surface or the outer circumferential surface and continues to the side wall; and a depth dimension in the radial direction from the inner circumferential surface or the outer circumferential surface is greater than that of the first portion. A notch is formed, the cutout portion having a second portion that includes a portion that is larger than the inner circumferential surface or the outer circumferential surface, and a second portion that is continuous at an intersecting angle that is nearly perpendicular to the inner circumferential surface or the outer circumferential surface, and the circumferential length of the first portion is is less than or equal to a predetermined length determined in relation to the depth dimension in the portion and the pressure difference generated between the long grooves.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9003588A JP2623289B2 (en) | 1988-04-12 | 1988-04-12 | Hydraulic control valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9003588A JP2623289B2 (en) | 1988-04-12 | 1988-04-12 | Hydraulic control valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01262257A true JPH01262257A (en) | 1989-10-19 |
| JP2623289B2 JP2623289B2 (en) | 1997-06-25 |
Family
ID=13987402
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9003588A Expired - Fee Related JP2623289B2 (en) | 1988-04-12 | 1988-04-12 | Hydraulic control valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2623289B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02100877U (en) * | 1989-01-30 | 1990-08-10 | ||
| EP0585107A1 (en) * | 1992-08-27 | 1994-03-02 | Trw Inc. | Steering control valve with contoured control surfaces |
-
1988
- 1988-04-12 JP JP9003588A patent/JP2623289B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02100877U (en) * | 1989-01-30 | 1990-08-10 | ||
| EP0585107A1 (en) * | 1992-08-27 | 1994-03-02 | Trw Inc. | Steering control valve with contoured control surfaces |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2623289B2 (en) | 1997-06-25 |
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