JP2007120438A - Variable displacement pump - Google Patents

Variable displacement pump Download PDF

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JP2007120438A
JP2007120438A JP2005315274A JP2005315274A JP2007120438A JP 2007120438 A JP2007120438 A JP 2007120438A JP 2005315274 A JP2005315274 A JP 2005315274A JP 2005315274 A JP2005315274 A JP 2005315274A JP 2007120438 A JP2007120438 A JP 2007120438A
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pump
chamber
fluid pressure
land portion
communication path
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JP4739912B2 (en
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Norio Kikuchi
典夫 菊地
Makoto Watanabe
誠 渡邉
Tomohiro Tanaka
智洋 田中
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Showa Corp
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Showa Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To stabilize delivery flow rate at a time of load generation without excessively reducing delivery flow rate at a time of low temperature load generation in a variable displacement pump. <P>SOLUTION: In the variable displacement pump 10 in which a change over valve device 60 has a valve element 64A opening and closing to a communication path 61 connecting a pressurizing chamber 66A communicating with the upstream side of a main restrictor 58 and connected to the first fluid pressure chamber 41, the valve element 64A of the change over valve device 60 is provided with a first land part 101 opening and closing the pressurizing chamber 66A to the communication path 61, and a second land part 102 communicating with a pump suction side path, and an annular groove 103 provided over all circumference between the first land part 101 and the second land part 102. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は自動車のパワーステアリング装置等に用いられる可変容量型ポンプに関する。   The present invention relates to a variable displacement pump used for a power steering device of an automobile.

従来、自動車の油圧パワーステアリング装置で操舵力をアシストするために、特許文献１に記載の如くの可変容量型ポンプが提案されている。この従来の可変容量型ポンプは、自動車のエンジンで直接回転駆動されるものであり、ポンプケーシングに嵌装したアダプタリングに移動変位可能に嵌装されたカムリング内にロータを設け、カムリングとロータの外周部との間にポンプ室を形成している。   Conventionally, a variable displacement pump as described in Patent Document 1 has been proposed in order to assist the steering force with a hydraulic power steering device of an automobile. This conventional variable displacement pump is directly rotated by an automobile engine. A rotor is provided in a cam ring that is movably fitted to an adapter ring that is fitted to a pump casing. A pump chamber is formed between the outer periphery.

そして、この従来技術では、カムリングをアダプタリング内で移動変位可能とし、かつポンプ室の容積が最大となるような付勢力をばねによりカムリングに付与するとともに、カムリングとアダプタリングとの間に第１と第２の流体圧室を分割形成し、ポンプ吐出側通路に設けた主絞りの上、下流側の圧力差によって作動し、ポンプ室からの圧力流体の吐出流量に応じて両流体圧室への供給流体圧を制御することによりカムリングを移動させる吐出流量制御装置を有し、結果として、ポンプ室の容積を変化させてポンプ室からの吐出流量を制御する。これにより、この可変容量型ポンプでは、回転数が低い自動車の停車時や低速走行時には大きな操舵アシスト力が得られるように吐出流量を大とし、回転数の高い高速走行時には操舵アシスト力を小さくするように吐出流量を一定量以下に制御し、パワーステアリング装置に要求される操舵アシスト力を発生可能としている。
特開2000-170668 In this prior art, the cam ring is movable and displaceable in the adapter ring, and an urging force that maximizes the volume of the pump chamber is applied to the cam ring by the spring, and the first is interposed between the cam ring and the adapter ring. And the second fluid pressure chamber are divided and operated by a pressure difference between the upstream side and the downstream side of the main throttle provided in the pump discharge side passage, and to both fluid pressure chambers according to the discharge flow rate of the pressure fluid from the pump chamber A discharge flow rate control device for moving the cam ring by controlling the supply fluid pressure of the pump chamber, and as a result, the discharge flow rate from the pump chamber is controlled by changing the volume of the pump chamber. As a result, in this variable displacement pump, the discharge flow rate is increased so that a large steering assist force can be obtained when the automobile having a low rotational speed is stopped or traveling at a low speed, and the steering assist force is decreased during a high speed traveling at a high rotational speed. In this way, the discharge flow rate is controlled to be equal to or less than a predetermined amount, and the steering assist force required for the power steering device can be generated.
JP2000-170668

特許文献１の吐出流量制御装置は、主絞りの上、下流側の圧力差によって作動し、ポンプ室からの圧力流体の吐出流量に応じて第１流体圧室への供給流体圧を制御する切換弁装置を有する。切換弁装置は、主絞りの上流側に連通する加圧室を、第１流体圧室に接続された連絡路に対して開閉する弁体を有する。このとき、弁体は、加圧室を上記連絡路に対して開閉する第１ランド部と、該連絡路をポンプ吸込側通路に連通する第２ランド部とを備え、ポンプの回転数が低い初期状態では、ポンプ吐出側圧力を印加されている加圧室が第１ランド部により第１流体圧室に対し遮断されるとともに、ポンプ吸込側圧力が第２ランド部により形成される隙間通路から連絡路を介して第１流体圧室に導入され、カムリングはポンプ室の容積を最大とする側に維持され、吐出流量を増加する。他方、ポンプの回転数が増加したときには、ポンプ吐出側圧力を印加されている加圧室が第１ランド部により開かれ、ポンプ吐出側圧力が連絡路を介して第１流体圧室に導入されるとともに、連絡路に導入されたポンプ吐出側圧力の一部が第２ランド部により形成される隙間通路を介してポンプ吸込側にリークせしめられ、カムリングはポンプ室の容積を適度に小さくする側に移動され、吐出流量を一定量以下に制御する。   The discharge flow rate control device of Patent Document 1 operates by a pressure difference between the upstream side and the downstream side of the main throttle, and switches the fluid pressure supplied to the first fluid pressure chamber according to the discharge flow rate of the pressure fluid from the pump chamber Has a valve device. The switching valve device has a valve body that opens and closes a pressurizing chamber communicating with the upstream side of the main throttle with respect to a communication path connected to the first fluid pressure chamber. At this time, the valve body includes a first land portion that opens and closes the pressurizing chamber with respect to the communication path, and a second land portion that communicates the communication path with the pump suction side passage, and the rotational speed of the pump is low. In the initial state, the pressurizing chamber to which the pump discharge side pressure is applied is blocked from the first fluid pressure chamber by the first land portion, and the pump suction side pressure is from the gap passage formed by the second land portion. The cam ring is introduced to the first fluid pressure chamber through the communication path, and the cam ring is maintained on the side where the volume of the pump chamber is maximized, thereby increasing the discharge flow rate. On the other hand, when the rotation speed of the pump increases, the pressurizing chamber to which the pump discharge side pressure is applied is opened by the first land portion, and the pump discharge side pressure is introduced into the first fluid pressure chamber via the communication path. In addition, a part of the pressure on the pump discharge side introduced into the communication path is leaked to the pump suction side through the gap passage formed by the second land portion, and the cam ring is a side for appropriately reducing the volume of the pump chamber. The discharge flow rate is controlled to a certain amount or less.

しかしながら、特許文献１の吐出流量制御装置では、低温の負荷発生時にポンプの回転数が増加し、切換弁装置の弁体が移動することにより、第１ランド部が加圧室を開いたとき、加圧室から連絡路に導入された作動油の粘度が低温の故に高いこと、並びに第２ランド部により形成される隙間通路が連絡路に臨む開口が狭小であることにより、この作動油が上記隙間通路に流入しにくい。このため、加圧室から第１流体圧室への連絡路に導入されたポンプ吐出側圧力は、第２ランド部により形成される隙間通路からポンプ吸込側にリークすることなく、第１流体圧室だけに充填され、カムリングはポンプ室の容積を過度に小さくする側に移動され、吐出流量を過度に減少させ、操舵力を重くしてしまう。   However, in the discharge flow rate control device of Patent Document 1, when the low-speed load is generated, the number of rotations of the pump increases, and the valve body of the switching valve device moves, so that the first land portion opens the pressurizing chamber. The hydraulic oil introduced into the communication path from the pressurizing chamber is high because of the low temperature, and the opening of the gap passage formed by the second land portion facing the communication path is narrow, so that the hydraulic oil is Difficult to flow into gap passage. For this reason, the pump discharge side pressure introduced into the communication path from the pressurizing chamber to the first fluid pressure chamber does not leak from the gap passage formed by the second land portion to the pump suction side. Only the chamber is filled, and the cam ring is moved to the side where the volume of the pump chamber is excessively reduced, thereby excessively reducing the discharge flow rate and increasing the steering force.

また、特許文献１の吐出流量制御装置では、切換弁装置の弁体の第２ランド部により形成される、連絡路からポンプ吸込側への通路面積が、弁体の移動位置により変動（第２ランド部が連絡路に臨む長さの変動）する。このため、負荷変動時に、加圧室から第１流体圧室への連絡路に導入された作動油のうち、ポンプ吸込側にリークする流量が不安定になり、つまりは第１流体圧室へのポンプ吐出側圧力の増大、カムリングの移動による吐出流量が減少し、操舵力が不安定になる。   Further, in the discharge flow rate control device of Patent Document 1, the passage area from the communication path to the pump suction side formed by the second land portion of the valve body of the switching valve device varies depending on the movement position of the valve body (second The length of the land facing the connecting road varies). For this reason, of the hydraulic oil introduced into the communication path from the pressurizing chamber to the first fluid pressure chamber when the load fluctuates, the flow rate that leaks to the pump suction side becomes unstable, that is, to the first fluid pressure chamber. The pump discharge side pressure increases, the discharge flow rate due to the movement of the cam ring decreases, and the steering force becomes unstable.

本発明の課題は、可変容量型ポンプにおいて、低温の負荷変動時における吐出流量を過度に減少させることなく、負荷発生時の吐出流量を安定化することにある。   An object of the present invention is to stabilize a discharge flow rate when a load is generated in a variable displacement pump without excessively reducing the discharge flow rate during a low-temperature load fluctuation.

請求項１の発明は、ポンプケーシングに挿入されるポンプ軸に固定して回転駆動されるとともに、多数のベーンを溝に収容して半径方向に移動可能としてなるロータと、ポンプケーシング内の嵌装孔に嵌装され、ロータの外周部との間にポンプ室を形成するとともに、ポンプケーシング内で移動変位可能とされ、ポンプケーシングとの間に第１と第２の流体圧室を形成するカムリングと、第１流体圧室にポンプ吐出側通路に設けた主絞りの上流側の圧力を導入し、第２流体圧室に該主絞りの下流側の圧力を導入する吐出流量制御装置とを有し、吐出流量制御装置が、主絞りの上、下流側の圧力差によって作動し、ポンプ室からの圧力流体の吐出流量に応じて第１流体圧室への供給流体圧を制御する切換弁装置を有し、切換弁装置が、主絞りの上流側に連通する加圧室を、第１流体圧室に接続された連絡路に対して開閉する弁体を有してなる可変容量型ポンプにおいて、切換弁装置の弁体は、加圧室を上記連絡路に対して開閉する第１ランド部と、該連絡路をポンプ吸込側通路に連通する第２ランド部とを備え、更に第１ランド部と第２ランド部の間の全周に渡って設けられる環状溝を備えるようにしたものである。   According to the first aspect of the present invention, there is provided a rotor that is rotationally driven while being fixed to a pump shaft that is inserted into a pump casing, and that accommodates a large number of vanes in a groove and is movable in a radial direction, and a fitting in the pump casing A cam ring which is fitted in the hole and forms a pump chamber between the outer periphery of the rotor and is movable and displaceable in the pump casing, and forms first and second fluid pressure chambers between the pump casing and And a discharge flow rate control device that introduces pressure upstream of the main throttle provided in the pump discharge side passage into the first fluid pressure chamber and introduces pressure downstream of the main throttle into the second fluid pressure chamber. The switching flow rate control device is operated by a pressure difference between the upstream side and the downstream side of the main throttle, and controls the supply fluid pressure to the first fluid pressure chamber according to the discharge flow rate of the pressure fluid from the pump chamber. And the switching valve device has a main throttle In a variable displacement pump having a valve body that opens and closes a pressurizing chamber communicating with the flow side with respect to a communication path connected to the first fluid pressure chamber, the valve body of the switching valve device is a pressurizing chamber. A first land portion that opens and closes the communication path, and a second land portion that communicates the communication path with the pump suction side passage, and further on the entire circumference between the first land portion and the second land portion. An annular groove provided across is provided.

請求項２の発明は、請求項１に記載の第２ランド部が第１ランド部より小外径をなすようにしたものである。   According to a second aspect of the present invention, the second land portion according to the first aspect has a smaller outer diameter than the first land portion.

請求項３の発明は、請求項１に記載の可変容量型ポンプを用いた自動車用油圧パワーステアリング装置である。   A third aspect of the present invention is an automotive hydraulic power steering apparatus using the variable displacement pump according to the first aspect.

（請求項１、２）
(a)可変容量型ポンプにあっては、切換弁装置の弁体が、加圧室を第１流体圧室への連絡路に対して開閉する第１ランド部と、該連絡路をポンプ吸込側通路に連通する第２ランド部とを備え、更に第１ランド部と第２ランド部の間の全周に渡って設けられる環状溝を備えるものとした。従って、低温の負荷発生時に切換弁装置の弁体が移動することにより、加圧室から連絡路に導入された作動油の粘度が低温の故に高い場合にも、この作動油は連絡路に広く臨む環状溝を介してその環状溝の全周から第２ランド部により形成される隙間通路にスムースに流入する。このため、加圧室から第１流体圧室への連絡路に導入されたポンプ吐出側圧力は、第１流体圧室に導入されるとともに、連絡路に導入されたポンプ吐出側圧力の一部が環状溝を介して第２ランド部により形成される隙間通路からポンプ吸込側にリークせしめられ、カムリングはポンプ室の容積を適度に大きくする側に移動され、吐出流量を適度に増大させる。従って、低温の負荷発生時における吐出流量を過度に減少させることがない。 (Claims 1 and 2)
(a) In the variable displacement pump, the valve body of the switching valve device opens and closes the pressurizing chamber with respect to the communication path to the first fluid pressure chamber, and pumps the communication path. A second land portion communicating with the side passage, and an annular groove provided over the entire circumference between the first land portion and the second land portion. Therefore, even when the viscosity of the hydraulic oil introduced from the pressurizing chamber into the communication path is high due to the low temperature due to the movement of the valve body of the switching valve device when a low temperature load is generated, this hydraulic oil is widely distributed in the communication path. It flows smoothly into the clearance passage formed by the second land portion from the entire circumference of the annular groove through the facing annular groove. For this reason, the pump discharge side pressure introduced into the communication path from the pressurization chamber to the first fluid pressure chamber is introduced into the first fluid pressure chamber and a part of the pump discharge side pressure introduced into the communication path. Is leaked from the clearance passage formed by the second land portion to the pump suction side through the annular groove, and the cam ring is moved to the side that appropriately increases the volume of the pump chamber, thereby appropriately increasing the discharge flow rate. Therefore, the discharge flow rate when a low temperature load is generated is not excessively reduced.

(b)可変容量型ポンプにあっては、切換弁装置の弁体の第２ランド部により形成される、連絡路からポンプ吸込側への通路面積は、連絡路に広く臨む環状溝を介することにより、弁体の移動位置により変動することがない。このため、負荷発生時に、加圧室から第１流体圧室への連絡路に導入された作動油のうち、ポンプ吸込側にリークする油量が不安定になることがなく、ひいては第１流体圧室の圧力が減少し、カムリングの移動による吐出流量が増大し、操舵力が安定化する。   (b) In the variable displacement pump, the passage area from the communication path to the pump suction side formed by the second land portion of the valve body of the switching valve device is through an annular groove that faces the communication path widely. Therefore, it does not vary depending on the movement position of the valve body. For this reason, the amount of oil leaking to the pump suction side among the hydraulic oil introduced into the communication path from the pressurizing chamber to the first fluid pressure chamber at the time of load generation does not become unstable, and as a result, the first fluid The pressure in the pressure chamber decreases, the discharge flow rate due to the movement of the cam ring increases, and the steering force is stabilized.

（請求項３）
(c)上述(a)の可変容量型ポンプを自動車用油圧パワーステアリング装置に適用することにより、低温の負荷発生時における吐出流量を過度に減少させることなく操舵力を重くしない。また、負荷発生時の吐出流量を安定化し、操舵アシスト力を安定化する。 (Claim 3)
(c) By applying the variable displacement pump of (a) described above to a hydraulic power steering device for an automobile, the steering force is not increased without excessively reducing the discharge flow rate when a low temperature load is generated. Moreover, the discharge flow rate at the time of load generation is stabilized, and the steering assist force is stabilized.

図１は可変容量型ポンプを示す断面図、図２は図１のII−II線に沿う断面図、図３は切換弁を示し、（Ａ）は断面図、（Ｂ）は要部拡大図、図４は切換弁の移動状態を示し、（Ａ）は低回転時を示す断面図、（Ｂ）は高回転時を示す断面図ある。   1 is a sectional view showing a variable displacement pump, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, FIG. 3 is a switching valve, (A) is a sectional view, and (B) is an enlarged view of a main part. 4A and 4B show the moving state of the switching valve, where FIG. 4A is a cross-sectional view showing when the engine is rotating at a low speed, and FIG.

可変容量型ポンプ１０は、自動車の油圧パワーステアリング装置の油圧発生源となるベーンポンプであり、図１、図２に示す如く、ポンプケーシング１１に挿入されるポンプ軸１２にセレーションにより固定されて回転駆動されるロータ１３を有している。ポンプケーシング１１は、ポンプハウジング１１Ａとカバー１１Ｂをボルト１４で一体化して構成され、軸受１５Ａ〜１５Ｃを介してポンプ軸１２を支持している。ポンプ軸１２は、自動車のエンジンで直接回転駆動可能とされている。   The variable displacement pump 10 is a vane pump serving as a hydraulic pressure generation source of a hydraulic power steering device of an automobile. As shown in FIGS. 1 and 2, the variable displacement pump 10 is rotationally driven by being fixed to a pump shaft 12 inserted into a pump casing 11 by serrations. The rotor 13 is provided. The pump casing 11 is configured by integrating a pump housing 11A and a cover 11B with bolts 14, and supports the pump shaft 12 via bearings 15A to 15C. The pump shaft 12 can be directly rotated by an automobile engine.

ロータ１３は周方向の多数位置のそれぞれに設けた溝１６にベーン１７を収容し、各ベーン１７を溝１６に沿う半径方向に移動可能としている。   The rotor 13 accommodates vanes 17 in grooves 16 provided at a plurality of positions in the circumferential direction, and the vanes 17 can be moved in the radial direction along the grooves 16.

ポンプケーシング１１のポンプハウジング１１Ａの嵌装孔２０には、プレッシャプレート１８、アダプタリング１９が積層状態で嵌着され、これらは後述する支点ピン２１によって周方向に位置決めされた状態でカバー１１Ｂにより側方から固定保持されている。支点ピン２１の一端はカバー１１Ｂに装着固定されている。   In the fitting hole 20 of the pump housing 11A of the pump casing 11, a pressure plate 18 and an adapter ring 19 are fitted in a laminated state, and these are positioned on the side by the cover 11B while being positioned in a circumferential direction by a fulcrum pin 21 described later. It is fixed and held from one side. One end of the fulcrum pin 21 is attached and fixed to the cover 11B.

ポンプケーシング１１のポンプハウジング１１Ａに固定されている上述のアダプタリング１９にはカムリング２２が嵌装されている。カムリング２２は、ロータ１３とある偏心量をもってロータ１３を囲み、プレッシャプレート１８とカバー１１Ｂの間で、ロータ１３の外周部との間にポンプ室２３を形成する。そして、ポンプ室２３のロータ回転方向上流側の吸込領域には、カバー１１Ｂに設けた吸込ポート２４が開口し、この吸込ポート２４にはハウジング１１Ａ、カバー１１Ｂに設けた吸込通路（ドレン通路）２５Ａ、２５Ｂを介してポンプ１０の吸込口２６が連通せしめられている。他方、ポンプ室２３のロータ回転方向下流側の吐出領域には、プレッシャプレート１８に設けた吐出ポート２７が開口し、この吐出ポート２７にはハウジング１１Ａに設けた高圧力室２８Ａ、吐出通路２８Ｂを介してポンプ１０の吐出口２９が連通せしめられている。   A cam ring 22 is fitted on the adapter ring 19 fixed to the pump housing 11 </ b> A of the pump casing 11. The cam ring 22 surrounds the rotor 13 with a certain amount of eccentricity with the rotor 13, and forms a pump chamber 23 between the pressure plate 18 and the cover 11 </ b> B and the outer periphery of the rotor 13. A suction port 24 provided in the cover 11B is opened in the suction region on the upstream side in the rotor rotation direction of the pump chamber 23. The suction port 24 has a suction passage (drain passage) 25A provided in the housing 11A and the cover 11B. , 25B, the suction port 26 of the pump 10 is communicated. On the other hand, a discharge port 27 provided in the pressure plate 18 opens in a discharge region downstream of the pump chamber 23 in the rotor rotation direction. The discharge port 27 has a high pressure chamber 28A and a discharge passage 28B provided in the housing 11A. The discharge port 29 of the pump 10 is communicated with each other.

これにより、可変容量型ポンプ１０にあっては、ポンプ軸１２によってロータ１３を回転駆動し、ロータ１３のベーン１７が遠心力でカムリング２２に押し付けられて回転するとき、ポンプ室２３のロータ回転方向上流側では隣り合うベーン１７間とカムリング２２とが囲む容積を回転とともに拡大して作動流体を吸込ポート２４から吸込み、ポンプ室２３のロータ回転方向下流側では隣り合うベーン１７間とカムリング２２とが囲む容積を回転とともに減縮して作動流体を吐出ポート２７から吐出する。   Thus, in the variable displacement pump 10, when the rotor 13 is rotationally driven by the pump shaft 12 and the vane 17 of the rotor 13 is pressed against the cam ring 22 by centrifugal force and rotates, the rotor rotation direction of the pump chamber 23 On the upstream side, the volume surrounded by the adjacent vanes 17 and the cam ring 22 is enlarged as the rotation rotates, and the working fluid is sucked in from the suction port 24. On the downstream side of the pump chamber 23 in the rotor rotation direction, the adjacent vanes 17 and the cam ring 22 The working volume is discharged from the discharge port 27 by reducing the volume enclosed by the rotation.

可変容量型ポンプ１０は、図２に示す如く、吐出ポート２７のポンプ軸１２まわりにおける開口範囲αを、後述する第２流体圧室４２の側に角度βだけずらして配置している。   As shown in FIG. 2, the variable displacement pump 10 is arranged such that the opening range α around the pump shaft 12 of the discharge port 27 is shifted by an angle β toward the second fluid pressure chamber 42 described later.

しかるに、可変容量型ポンプ１０は、吐出流量制御装置４０を有している。
吐出流量制御装置４０は、ポンプケーシング１１に固定されている上述のアダプタリング１９の鉛直最下部に前述の支点ピン２１を載置し、カムリング２２の鉛直最下部をこの支点ピン２１に支持し、カムリング２２をアダプタリング１９内で揺動変位可能としている。 However, the variable displacement pump 10 has a discharge flow rate control device 40.
The discharge flow rate control device 40 places the aforementioned fulcrum pin 21 on the lowest vertical part of the aforementioned adapter ring 19 fixed to the pump casing 11, and supports the lowest vertical part of the cam ring 22 on this fulcrum pin 21. The cam ring 22 can be oscillated and displaced within the adapter ring 19.

吐出流量制御装置４０は、ポンプケーシング１１を構成するポンプハウジング１１Ａにおいて、カムリング２２を挟んで後述する第１流体圧室４１の反対側に加圧シリンダ５０を螺着しＯリングを介する密封状態で設け、加圧シリンダ５０の油室５１に吐出通路２８Ｂから分岐した分岐連通路２８Ｃを連通し、この油室５１に挿入したピストン５２を、アダプタリング１９に設けたピストン孔５３を通してカムリング２２の外面に衝接している。また、加圧シリンダ５０の油室５１に付勢手段としてのばね５４を配設し、ばね５４はピストン５２を介してカムリング２２をロータ１３の外周部との間でポンプ室２３の容積（ポンプ容量）を最大とする方向へ付勢している。ピストン５２はばね５４を収容する空洞を備えた一端閉塞円筒中空体からなる。   In the pump housing 11A constituting the pump casing 11, the discharge flow rate control device 40 is screwed in a pressure cylinder 50 on the opposite side of a first fluid pressure chamber 41 (to be described later) with the cam ring 22 interposed therebetween, in a sealed state via an O-ring. The branch communication passage 28C branched from the discharge passage 28B is communicated with the oil chamber 51 of the pressurizing cylinder 50, and the piston 52 inserted into the oil chamber 51 is passed through the piston hole 53 provided in the adapter ring 19 to the outer surface of the cam ring 22. Struck with. In addition, a spring 54 as an urging means is disposed in the oil chamber 51 of the pressurizing cylinder 50, and the spring 54 has a capacity of the pump chamber 23 (pump) between the cam ring 22 and the outer peripheral portion of the rotor 13 via the piston 52. It is energizing in the direction that maximizes (capacity). The piston 52 is formed of a cylindrical hollow body having one end closed and a cavity for accommodating the spring 54.

尚、アダプタリング１９は第１流体圧室４１を形成する内周部の一部にカムリング移動規制ストッパ１９Ａを突状形成され、後述するようにポンプ室２３の容積を最大とするカムリング２２の移動限を規制される。また、アダプタリング１９は後述する第２流体圧室４２を形成する内周部の一部にカムリング移動規制ストッパ１９Ｂを突状形成され、後述するようにポンプ室２３の容積を最小とするカムリング２２の移動限を規制される。   The adapter ring 19 is formed with a cam ring movement restricting stopper 19A in a protruding shape on a part of the inner peripheral portion forming the first fluid pressure chamber 41, and the cam ring 22 moves to maximize the volume of the pump chamber 23 as will be described later. The limit is regulated. Further, the adapter ring 19 has a cam ring movement restricting stopper 19B protruding from a part of an inner peripheral portion forming a second fluid pressure chamber 42 which will be described later, and the cam ring 22 which minimizes the volume of the pump chamber 23 as will be described later. The movement limit is regulated.

また、吐出流量制御装置４０は、カムリング２２とアダプタリング１９との間に第１と第２の流体圧室４１、４２を形成している。即ち、第１流体圧室４１と第２流体圧室４２は、カムリング２２とアダプタリング１９の間で、支点ピン２１と、その軸対称位置に設けたシール材４３とで分割される。このとき、第１と第２の流体圧室４１、４２は、カムリング２２とアダプタリング１９の間の両側方をカバー１１Ｂとプレッシャプレート１８により区画され、アダプタリング１９の前述したカムリング移動規制ストッパ１９Ａ、１９Ｂにカムリング２２が衝合したときに、ストッパ１９Ａの両側に分離される第１流体圧室４１同士を連絡する連絡溝、ストッパ１９Ｂの両側に分離される第２流体圧室４２同士を連絡する連絡溝をプレッシャプレート１８に備える。   In addition, the discharge flow rate control device 40 forms first and second fluid pressure chambers 41 and 42 between the cam ring 22 and the adapter ring 19. That is, the first fluid pressure chamber 41 and the second fluid pressure chamber 42 are divided between the cam ring 22 and the adapter ring 19 by the fulcrum pin 21 and the seal material 43 provided at the axially symmetric position. At this time, the first and second fluid pressure chambers 41 and 42 are partitioned on both sides between the cam ring 22 and the adapter ring 19 by the cover 11B and the pressure plate 18, and the above-described cam ring movement restriction stopper 19A of the adapter ring 19 is provided. , 19B, when the cam ring 22 abuts, the communication groove connecting the first fluid pressure chambers 41 separated on both sides of the stopper 19A, and the second fluid pressure chambers 42 separated on both sides of the stopper 19B are communicated. The pressure plate 18 is provided with a connecting groove.

ここで、前述の加圧シリンダ５０の油室５１はポンプ１０の吐出通路２８Ｂに連通路２８Ｃを介して連通している。これにより、ポンプ１０の吐出経路において、ポンプ室２３から吐出されてプレッシャプレート１８の吐出ポート２７、ポンプハウジング１１Ａの高圧力室２８Ａを経由して吐出通路２８Ｂに達した圧力流体は、連通路２８Ｃを介して、加圧シリンダ５０の周囲の環状溝５５Ａ、該加圧シリンダ５０の壁面に開口した通路５５Ｂから油室５１に充填される。他方、吐出通路２８Ｂにおいて、連通路２８Ｃの分岐部より下流側には主絞り５８が設けられる。   Here, the oil chamber 51 of the pressure cylinder 50 described above communicates with the discharge passage 28B of the pump 10 through the communication passage 28C. Thereby, in the discharge path of the pump 10, the pressure fluid discharged from the pump chamber 23 and reaching the discharge passage 28B via the discharge port 27 of the pressure plate 18 and the high pressure chamber 28A of the pump housing 11A is communicated with the communication passage 28C. The oil chamber 51 is filled from the annular groove 55A around the pressure cylinder 50 and the passage 55B opened in the wall surface of the pressure cylinder 50. On the other hand, in the discharge passage 28B, a main throttle 58 is provided downstream of the branch portion of the communication passage 28C.

そして、吐出流量制御装置４０は、(1)ポンプ室２３の容積を最小とする方向への移動変位をカムリング２２に与える第１流体圧室４１に、主絞り５８の上流側の圧力を後述する切換弁装置６０を介して導入し、(2)ポンプ室２３の容積を最大とする方向への移動変位をカムリング２２に与える第２流体圧室４２に、主絞り５８の下流側の圧力を吐出通路２８Ｂから分岐連通路２８Ｄ経由でアダプタリング１９のピストン孔５３を介して導入し、(3)ポンプ室２３の容積を最大とする方向への移動変位をカムリング２２に与える加圧シリンダ５０の油室５１に、主絞り５８の上流側の圧力を吐出通路２８Ｂから分岐連通路２８Ｄ経由で加圧シリンダ５０の通路５５Ａ、５５Ｂを介して導入する。第１流体圧室４１、第２流体圧室４２、加圧シリンダ５０の油室５１に作用する圧力のバランスによって、カムリング２２をばね５４の付勢力に抗して移動させ、ポンプ室２３の容積を変化させてポンプ１０の吐出流量を制御する。   Then, the discharge flow rate control device 40 (1) describes the pressure upstream of the main throttle 58 in the first fluid pressure chamber 41 that gives the cam ring 22 displacement in the direction that minimizes the volume of the pump chamber 23. Introduced via the switching valve device 60, (2) the pressure downstream of the main throttle 58 is discharged to the second fluid pressure chamber 42 that gives the cam ring 22 displacement in the direction that maximizes the volume of the pump chamber 23. The oil in the pressurizing cylinder 50 is introduced from the passage 28B via the branch communication passage 28D through the piston hole 53 of the adapter ring 19 and (3) the cam ring 22 is displaced in the direction that maximizes the volume of the pump chamber 23. The pressure on the upstream side of the main throttle 58 is introduced into the chamber 51 from the discharge passage 28B via the branch communication passage 28D through the passages 55A and 55B of the pressure cylinder 50. The cam ring 22 is moved against the urging force of the spring 54 by the balance of pressures acting on the first fluid pressure chamber 41, the second fluid pressure chamber 42, and the oil chamber 51 of the pressurizing cylinder 50. Is controlled to control the discharge flow rate of the pump 10.

ここで、吐出流量制御装置４０にあっては、主絞り５８の上、下流側の圧力差によって作動し、ポンプ室２３からの圧力流体の吐出流量に応じて第１流体圧室４１への供給流体圧を制御する切換弁装置６０を有する。具体的には、切換弁装置６０は、第１流体圧室４１に接続された連絡路６１と吐出通路２８Ｂの主絞り５８より上流側の連絡路６７との間に介装され、連絡路６１に設けた絞り６１Ａとの連携により、ポンプ１０の低回転域では第１流体圧室４１を連絡路６７に対して閉じ、高回転域では第１流体圧室４１を連絡路６７に接続する。   Here, the discharge flow rate control device 40 is operated by a pressure difference between the upstream side and the downstream side of the main throttle 58, and is supplied to the first fluid pressure chamber 41 according to the discharge flow rate of the pressure fluid from the pump chamber 23. A switching valve device 60 for controlling the fluid pressure is provided. Specifically, the switching valve device 60 is interposed between the communication path 61 connected to the first fluid pressure chamber 41 and the communication path 67 on the upstream side of the main throttle 58 of the discharge path 28B. The first fluid pressure chamber 41 is closed with respect to the communication path 67 in the low rotation range of the pump 10, and the first fluid pressure chamber 41 is connected to the communication path 67 in the high rotation range, in cooperation with the throttle 61 </ b> A provided in FIG.

尚、切換弁装置６０は、ポンプハウジング１１Ａに穿設した弁格納孔６２にスプリング６３、切換弁６４を収容し、スプリング６３で付勢される切換弁６４をポンプハウジング１１Ａに螺着したキャップ６５で担持している。切換弁６４は、弁格納孔６２に密に摺接する弁体６４Ａ、及び切換弁体６４Ｂを備え、弁体６４Ａの一端側に設けた加圧室６６Ａに吐出通路２８Ｂの主絞り５８より上流側の連絡路６７を連通し、切換弁体６４Ｂの他端側に設けたスプリング６３が格納されている背圧室６６Ｂに吐出通路２８Ｂの主絞り５８より下流側の連絡路６８を第２流体圧室４２を介して連通している。また、弁体６４Ａと切換弁体６４Ｂの間のドレン室６６Ｃには前述した吸込通路（ドレン通路）２５Ａが貫通して形成され、タンクに連絡される。弁体６４Ａは、前述の連絡路６１を開閉可能としている。即ち、ポンプ１０の吐出圧力が低い低回転域では、スプリング６３の付勢力により切換弁６４を図２に示す原位置に設定し、弁体６４Ａにより加圧室６６Ａを第１流体圧室４１への連絡路６１に対して閉じる。ポンプ１０の中高回転域では、加圧室６６Ａに加えられる連絡路６７の高圧流体により切換弁６４を移動させ、弁体６４Ａにより加圧室６６Ａを第１流体圧室４１への連絡路６１に対して開き、連絡路６７から加圧室６６Ａに加えられている高圧流体を第１流体圧室４１に導入する。尚、連絡路６７には絞り６７Ａが設けられ、主絞り５８の上流側からの脈動を吸収可能とする。   The switching valve device 60 accommodates a spring 63 and a switching valve 64 in a valve storage hole 62 formed in the pump housing 11A, and a cap 65 in which the switching valve 64 biased by the spring 63 is screwed to the pump housing 11A. It is supported by. The switching valve 64 includes a valve body 64A that is in close sliding contact with the valve storage hole 62, and a switching valve body 64B. The pressurizing chamber 66A provided on one end side of the valve body 64A is upstream of the main throttle 58 of the discharge passage 28B. The communication path 67 is connected to the back pressure chamber 66B in which the spring 63 provided on the other end of the switching valve body 64B is stored, and the communication path 68 downstream of the main throttle 58 of the discharge passage 28B is connected to the second fluid pressure. It communicates through the chamber 42. Further, the above-described suction passage (drain passage) 25A is formed through the drain chamber 66C between the valve body 64A and the switching valve body 64B and communicates with the tank. The valve body 64A is capable of opening and closing the connecting path 61 described above. That is, in the low rotation range where the discharge pressure of the pump 10 is low, the switching valve 64 is set to the original position shown in FIG. 2 by the biasing force of the spring 63, and the pressurizing chamber 66A is moved to the first fluid pressure chamber 41 by the valve body 64A. The communication path 61 is closed. In the middle and high rotation range of the pump 10, the switching valve 64 is moved by the high-pressure fluid in the communication path 67 applied to the pressurizing chamber 66A, and the pressurizing chamber 66A is connected to the first fluid pressure chamber 41 by the valve body 64A. On the other hand, the high-pressure fluid applied to the pressurizing chamber 66 </ b> A from the communication path 67 is introduced into the first fluid pressure chamber 41. The communication path 67 is provided with a throttle 67A so that pulsation from the upstream side of the main throttle 58 can be absorbed.

従って、吐出流量制御装置４０を用いたポンプ１０の吐出流量特性は以下の如くになる。
(1)ポンプ１０の回転数が低い自動車の低速走行域では、ポンプ室２３から吐出されて切換弁装置６０の加圧室６６Ａに及ぶ流体の圧力が未だ低く、切換弁６４は原位置に位置し、切換弁６４は加圧室６６Ａを第１流体圧室４１への連絡路６１に対して閉じる。このため、主絞り５８の上流側の圧力は第１流体圧室４１に供給されず、第２流体圧室４２には主絞り５８の下流側の圧力が印加され、加圧シリンダ５０の油室５１には主絞り５８の上流側の圧力が印加される。このため、カムリング２２は第１流体圧室４１と第２流体圧室４２の圧力差と加圧シリンダ５０のピストン５２の押し力とばね５４の付勢力によりポンプ室２３の容積を最大とする側に維持され、ポンプ１０の吐出流量は、回転数に比例して増加する。 Therefore, the discharge flow rate characteristic of the pump 10 using the discharge flow rate control device 40 is as follows.
(1) In a low-speed traveling region of an automobile in which the rotation speed of the pump 10 is low, the pressure of the fluid discharged from the pump chamber 23 and reaching the pressurizing chamber 66A of the switching valve device 60 is still low, and the switching valve 64 is in the original position. The switching valve 64 closes the pressurizing chamber 66A with respect to the communication path 61 to the first fluid pressure chamber 41. For this reason, the pressure on the upstream side of the main throttle 58 is not supplied to the first fluid pressure chamber 41, and the pressure on the downstream side of the main throttle 58 is applied to the second fluid pressure chamber 42. A pressure on the upstream side of the main throttle 58 is applied to 51. For this reason, the cam ring 22 is a side that maximizes the volume of the pump chamber 23 by the pressure difference between the first fluid pressure chamber 41 and the second fluid pressure chamber 42, the pushing force of the piston 52 of the pressurizing cylinder 50, and the biasing force of the spring 54. The discharge flow rate of the pump 10 increases in proportion to the rotation speed.

(2)ポンプ１０の回転数の増加により、ポンプ室２３から吐出されて切換弁装置６０の加圧室６６Ａに及ぶ流体の圧力が高くなると、切換弁装置６０はスプリング６３の付勢力に抗して切換弁６４を移動させて加圧室６６Ａを第１流体圧室４１への連絡路６１に対して開く。これにより、第１流体圧室４１の圧力が上がり、カムリング２２はポンプ室２３の容積を小さくする側に移動していく。従って、ポンプ１０の吐出流量は、回転数の増加に対し、回転数の増加による流量増加分と、ポンプ室２３の容積減縮による流量減少分とを相殺し、一定の流量を維持する。   (2) When the pressure of the fluid discharged from the pump chamber 23 and reaching the pressurizing chamber 66A of the switching valve device 60 increases due to an increase in the rotation speed of the pump 10, the switching valve device 60 resists the urging force of the spring 63. The switching valve 64 is moved to open the pressurizing chamber 66 </ b> A with respect to the communication path 61 to the first fluid pressure chamber 41. As a result, the pressure in the first fluid pressure chamber 41 increases, and the cam ring 22 moves to the side of reducing the volume of the pump chamber 23. Therefore, the discharge flow rate of the pump 10 maintains a constant flow rate by offsetting the increase in flow rate due to the increase in rotation rate and the decrease in flow rate due to the volume reduction of the pump chamber 23 with respect to the increase in rotation rate.

しかるに、ポンプ１０にあっては、切換弁装置６０の切換弁６４の弁体６４Ａが、図３、図４に示す如く、加圧室６６Ａを第１流体圧室４１への連絡路６１に対して開閉する円筒状第１ランド部１０１と、該連絡路６１を第１ランド部１０１とともにドレン室６６Ｃに対して開閉する円筒状第２ランド部１０２を備える。このとき、第１ランド部１０１は弁格納孔６２に密に摺接し、第２ランド部１０２は第１ランド部１０１より小外径をなして弁格納孔６２との間に隙間通路１０２Ａを形成する。更に、弁体６４Ａは、第１ランド部１０１と第２ランド部１０２に挟まれる間に、該弁体６４Ａの全周に渡る環状溝１０３を備える。弁体６４Ａが加圧室６６Ａを第１流体圧室４１への連絡路６１に対して開閉する行程において、ポンプ１０の無負荷持には、図４（Ａ）に示す如く、第１ランド部１０１が加圧室６６Ａを連絡路６１に対して閉じる。ポンプ１０の負荷発生時又は中回転時には図４（Ｂ）に示す如く、第１ランド部１０１が加圧室６６Ａを連絡路６１に対して開き、環状溝１０３を連絡路６１に臨むように位置付ける。ポンプ１６の高回転持には、図４（Ｃ）に示す如く、第１ランド部１０１が連絡路６１をドレン室６６Ｃに対して閉じる。   However, in the pump 10, the valve body 64 </ b> A of the switching valve 64 of the switching valve device 60 connects the pressurizing chamber 66 </ b> A to the communication path 61 to the first fluid pressure chamber 41 as shown in FIGS. 3 and 4. A cylindrical first land portion 101 that opens and closes, and a cylindrical second land portion 102 that opens and closes the communication path 61 with respect to the drain chamber 66C together with the first land portion 101. At this time, the first land portion 101 is in close sliding contact with the valve storage hole 62, and the second land portion 102 has a smaller outer diameter than the first land portion 101 and forms a clearance passage 102 </ b> A with the valve storage hole 62. To do. Furthermore, the valve body 64 </ b> A includes an annular groove 103 extending over the entire circumference of the valve body 64 </ b> A while being sandwiched between the first land portion 101 and the second land portion 102. In the stroke in which the valve body 64A opens and closes the pressurizing chamber 66A with respect to the communication path 61 to the first fluid pressure chamber 41, the first land portion is used as shown in FIG. 101 closes the pressurizing chamber 66 </ b> A with respect to the communication path 61. When the load of the pump 10 is generated or during the middle rotation, the first land portion 101 opens the pressurizing chamber 66A with respect to the communication path 61 and positions the annular groove 103 so as to face the communication path 61 as shown in FIG. . In order to keep the pump 16 rotating at a high speed, as shown in FIG. 4C, the first land portion 101 closes the communication path 61 with respect to the drain chamber 66C.

尚、弁体６４Ａは、第１ランド部１０１の加圧室６６Ａ寄り外周端を該加圧室６６Ａの側に向けて縮径するテーパ面とし、第２ランド部１０２のドレン室６６Ｃ寄り外周端を該ドレン室６６Ｃの側に向けて縮径するテーパ面とし、環状溝１０３の両側端を互いに拡開するテーパ面としている。   The valve body 64A has an outer peripheral end near the pressurizing chamber 66A of the first land portion 101 as a tapered surface whose diameter is reduced toward the pressurizing chamber 66A, and an outer peripheral end near the drain chamber 66C of the second land portion 102. Are tapered surfaces that reduce in diameter toward the drain chamber 66C, and both side ends of the annular groove 103 are tapered surfaces that expand each other.

従って、本実施例によれば以下の作用効果を奏する。
(a)可変容量型ポンプ１０にあっては、切換弁装置６０の弁体６４Ａが、加圧室６６Ａを第１流体圧室４１への連絡路６１に対して開閉する第１ランド部１０１と、該連絡路６１をドレン室６６Ｃに連通する第２ランド部１０２とを備え、更に第１ランド部１０１と第２ランド部１０２の間の全周に渡って設けられる環状溝１０３を備えるものとした。従って、低温の負荷発生時に切換弁装置６０の弁体６４Ａが移動することにより、加圧室６６Ａから連絡路６１に導入された作動油の粘度が低温の故に高い場合にも、この作動油は連絡路６１に広く臨む環状溝１０３を介してその環状溝１０３の全周から第２ランド部１０２により形成される隙間通路１０２Ａにスムースに流入する。このため、加圧室６６Ａから第１流体圧室４１への連絡路６１に導入されたポンプ吐出側圧力は、第１流体圧室４１に導入されるとともに、連絡路６１に導入されたポンプ吐出側圧力の一部が環状溝１０３を介して第２ランド部１０２により形成される隙間通路１０２Ａからポンプ吸込側にリークせしめられ、カムリング２２はポンプ室２３の容積を適度に大きくする側に移動され、吐出流量を適度に増大させる。従って、低温の負荷発生時における吐出流量を過度に減少させることがない。 Therefore, according to the present embodiment, the following operational effects can be obtained.
(a) In the variable displacement pump 10, the valve body 64 </ b> A of the switching valve device 60 includes the first land portion 101 that opens and closes the pressurizing chamber 66 </ b> A with respect to the communication path 61 to the first fluid pressure chamber 41. A second land portion 102 that communicates the communication path 61 with the drain chamber 66C, and further includes an annular groove 103 provided over the entire circumference between the first land portion 101 and the second land portion 102. did. Accordingly, even when the viscosity of the hydraulic oil introduced from the pressurizing chamber 66A into the communication path 61 is high due to the low temperature due to the movement of the valve body 64A of the switching valve device 60 when a low temperature load is generated, the hydraulic oil is It flows smoothly into the clearance passage 102 </ b> A formed by the second land portion 102 from the entire circumference of the annular groove 103 through the annular groove 103 that widely faces the communication path 61. For this reason, the pump discharge side pressure introduced into the communication path 61 from the pressurizing chamber 66A to the first fluid pressure chamber 41 is introduced into the first fluid pressure chamber 41 and the pump discharge introduced into the communication path 61. A part of the side pressure is leaked to the pump suction side from the gap passage 102A formed by the second land portion 102 via the annular groove 103, and the cam ring 22 is moved to the side for appropriately increasing the volume of the pump chamber 23. The discharge flow rate is increased moderately. Therefore, the discharge flow rate when a low temperature load is generated is not excessively reduced.

(b)可変容量型ポンプ１０にあっては、切換弁装置６０の弁体６４Ａの第２ランド部１０２により形成される、連絡路６１からポンプ吸込側への通路面積は、連絡路６１に広く臨む環状溝１０３を介することにより、弁体６４Ａの移動位置により変動することがない。このため、負荷発生時に、加圧室６６Ａから第１流体圧室４１への連絡路６１に導入された作動油のうち、ポンプ吸込側にリークする油量が不安定になることがなく、ひいては第１流体圧室４１の圧力が減少し、カムリング２２の移動により、吐出流量が増大する。   (b) In the variable displacement pump 10, the passage area from the communication path 61 to the pump suction side formed by the second land portion 102 of the valve body 64 </ b> A of the switching valve device 60 is wide in the communication path 61. By passing through the facing annular groove 103, there is no fluctuation depending on the moving position of the valve body 64A. For this reason, the amount of oil leaking to the pump suction side of the hydraulic oil introduced into the communication path 61 from the pressurizing chamber 66A to the first fluid pressure chamber 41 does not become unstable when a load is generated. The pressure in the first fluid pressure chamber 41 decreases, and the discharge flow rate increases as the cam ring 22 moves.

(c)上述(a)の可変容量型ポンプ１０を自動車用油圧パワーステアリング装置に適用することにより、低温の負荷発生時における吐出流量を過度に減少させることなく操舵力を重くしない。また、負荷発生時の吐出流量を安定化し、操舵アシスト力を安定化する。   (c) By applying the variable displacement pump 10 of (a) described above to a hydraulic power steering apparatus for automobiles, the steering force is not increased without excessively reducing the discharge flow rate when a low temperature load is generated. Moreover, the discharge flow rate at the time of load generation is stabilized, and the steering assist force is stabilized.

尚、ポンプ１０にあっては、高圧力室２８Ａと吸込通路（ドレン通路）２５Ａと、ドレン室６６Ｃの間に、ポンプ吐出側での過大流体圧をリリーフする切換弁としてのリリーフ弁７０を有している。また、ポンプ１０は、吸込通路２５Ｂからポンプ軸１２の軸受１５Ｃに向かう潤滑油供給路９１をカバー１１Ｂに穿設し、ポンプ軸１２の軸受１５Ｂまわりから吸込通路２５Ａに戻る潤滑油戻り路９２をポンプハウジング１１Ａに穿設してある。   The pump 10 has a relief valve 70 as a switching valve that relieves excessive fluid pressure on the pump discharge side between the high pressure chamber 28A, the suction passage (drain passage) 25A, and the drain chamber 66C. is doing. Further, the pump 10 pierces the cover 11B with a lubricating oil supply passage 91 from the suction passage 25B toward the bearing 15C of the pump shaft 12, and a lubricating oil return passage 92 that returns from the periphery of the bearing 15B of the pump shaft 12 to the suction passage 25A. It is drilled in the pump housing 11A.

リリーフ弁７０は、図３に示す如く、切換弁装置６０に内蔵され、切換弁６４そのものからなる主弁７１にパイロット弁を構成するボール７３を付帯させたパイロット作動型にて構成されている。そして、主弁７１は、ポンプ吐出側通路に設けた主絞り５８の上流側通路、換言すれば第１弁室（加圧室６６Ａと同じ）８１をドレン通路２５Ａ（吸込通路）に対し開閉可能とする。また、ボール７３には、ポンプ吐出側通路に設けた主絞り５８の下流側の流体圧、ひいては第２弁室（背圧室６６Ｂと同じ）８２の流体圧が印加される。   As shown in FIG. 3, the relief valve 70 is built in a switching valve device 60, and is configured as a pilot operated type in which a ball 73 constituting a pilot valve is attached to a main valve 71 including the switching valve 64 itself. The main valve 71 can open and close the upstream passage of the main throttle 58 provided in the pump discharge side passage, in other words, the first valve chamber (same as the pressurizing chamber 66A) 81 with respect to the drain passage 25A (suction passage). And Further, the fluid pressure on the downstream side of the main throttle 58 provided in the pump discharge side passage and the fluid pressure in the second valve chamber (same as the back pressure chamber 66B) 82 are applied to the ball 73.

具体的には、リリーフ弁７０は、下記(a)〜(c)の構成を備える。
(a)リリーフ弁７０は、弁格納孔６２内に摺動可能に主弁７１（切換弁６４）を設け、弁格納孔６２の主弁７１に対する一端側に定めた第１弁室８１（加圧室６６Ａ）には、ポンプ１０の吐出側通路に設けた主絞り５８の上流側の流体圧を印加する。また、弁格納孔６２の主弁７１に対する他端側に定めた第２弁室８２（背圧室６６Ｂ）には、該主絞り５８の下流側の流体圧を印加する。そして、リリーフ弁７０は、第１弁室８１をドレン室６６Ｃ経由でドレン通路２５Ａに連絡するリリーフ路８３（不図示）を弁格納孔６２に設け、主弁７１を第１弁室８１の側に付勢して主弁７１をリリーフ路８３の閉じ位置に設定するスプリング８４（スプリング６３と同じ）を備える。 Specifically, the relief valve 70 has the following configurations (a) to (c).
(a) The relief valve 70 is provided with a main valve 71 (switching valve 64) slidably in the valve storage hole 62, and a first valve chamber 81 (additional valve) defined on one end side of the valve storage hole 62 with respect to the main valve 71. A fluid pressure upstream of the main throttle 58 provided in the discharge side passage of the pump 10 is applied to the pressure chamber 66A). A fluid pressure downstream of the main throttle 58 is applied to the second valve chamber 82 (back pressure chamber 66B) defined on the other end side of the valve storage hole 62 with respect to the main valve 71. The relief valve 70 is provided with a relief passage 83 (not shown) for connecting the first valve chamber 81 to the drain passage 25A via the drain chamber 66C in the valve storage hole 62, and the main valve 71 is provided on the first valve chamber 81 side. And a spring 84 (same as the spring 63) that biases the main valve 71 to the closed position of the relief path 83.

(b)リリーフ弁７０は、流体圧をリリーフするための軸孔７１Ａが形成されるとともに該軸孔７１Ａに交差するリリーフ孔７１Ｂが形成されて弁格納孔６２に摺動可能に設けられる主弁７１と、主弁７１の軸孔７１Ａの流入側開口端に挿着されて該軸孔７１Ａの内外を連通する連通孔７２Ａを備えるとともに該連通孔７２Ａの流出側端にボール受面７２Ｂが形成された弁シート７２と、主弁７１の軸孔７１Ａに移動可能に設けられていて弁シート７２のボール受面７２Ｂに当接可能とされるボール７３と、主弁７１の軸孔７１Ａに設けられていてスプリング７５にバックアップされる状態でボール７３を弁シート７２のボール受面７２Ｂに押圧するボール押面７４Ａを備えたスプリング押え７４とを有する。尚、７１Ｃは主弁７１のスプリング７５を収容する軸孔７１Ａの側壁に設けられてスプリング押え７４の移動をスムースにするためにドレン室６６Ｃ、ドレン通路２５Ａに対向している流体圧逃し孔（リリーフ孔）である。   (b) The relief valve 70 is formed with a shaft hole 71A for relief of fluid pressure and a relief hole 71B that intersects the shaft hole 71A, and is slidably provided in the valve storage hole 62. 71 and a communication hole 72A that is inserted and attached to the inflow side opening end of the shaft hole 71A of the main valve 71 and communicates the inside and outside of the shaft hole 71A, and a ball receiving surface 72B is formed at the outflow side end of the communication hole 72A. Provided in the shaft hole 71A of the main valve 71, and a ball 73 that is movably provided in the shaft hole 71A of the main valve 71 and that can be brought into contact with the ball receiving surface 72B of the valve seat 72. And a spring retainer 74 having a ball pressing surface 74A for pressing the ball 73 against the ball receiving surface 72B of the valve seat 72 in a state of being backed up by the spring 75. 71C is provided on the side wall of the shaft hole 71A that accommodates the spring 75 of the main valve 71, and in order to make the movement of the spring retainer 74 smooth, a fluid pressure relief hole (facing the drain chamber 66C and the drain passage 25A). Relief hole).

(c)リリーフ弁７０の弁シート７２のボール受面７２Ｂを、その連通孔７２Ａの軸方向で流体が流出する方向に向けて拡開するテーパ面とする。同時に、スプリング押え７４のボール押面７４Ａの周辺端面７４Ｂを、該スプリング押え７４の軸方向で反ボール押圧方向に向けて拡開するテーパ面とする。   (c) The ball receiving surface 72B of the valve seat 72 of the relief valve 70 is a tapered surface that expands in the direction in which the fluid flows out in the axial direction of the communication hole 72A. At the same time, the peripheral end surface 74B of the ball pressing surface 74A of the spring retainer 74 is a tapered surface that expands in the axial direction of the spring retainer 74 in the anti-ball pressing direction.

リリーフ弁７０は、ポンプ１０が用いられているパワーステアリング装置による操舵の据え切り状態が持続する等により、ポンプ吐出側での流体圧が過大になり、主絞り５８の下流側の吐出通路につながっている第２弁室８２の流体圧がリリーフ設定圧に達すると、第２弁室８２の流体圧がボール７３をスプリング７５に抗して開動作せしめる。これにより、第２弁室８２の流体圧をリリーフ孔７１Ｂからドレン室６６Ｃ経由でドレン通路２５Ａへリリーフし、このリリーフによる第２弁室８２の流体圧の低減状態下で、主弁７１を第１弁室８１の流体圧によりスプリング８４に抗して開動作させ、結果として第１弁室８１の流体圧をリリーフ路８３からドレン室６６Ｃ経由でドレン通路２５Ａへリリーフ可能とする。これにより、ポンプ吐出側の過大流体圧をリリーフできるものとなる。   The relief valve 70 is connected to the discharge passage on the downstream side of the main throttle 58 because the fluid pressure on the pump discharge side becomes excessive due to the stationary state of steering by the power steering device in which the pump 10 is used. When the fluid pressure in the second valve chamber 82 reaches the relief set pressure, the fluid pressure in the second valve chamber 82 opens the ball 73 against the spring 75. As a result, the fluid pressure in the second valve chamber 82 is relieved from the relief hole 71B to the drain passage 25A via the drain chamber 66C, and the main valve 71 is moved under the reduced state of the fluid pressure in the second valve chamber 82 by this relief. As a result, the fluid pressure in the first valve chamber 81 can be relieved from the relief passage 83 to the drain passage 25A via the drain chamber 66C. Thereby, the excessive fluid pressure on the pump discharge side can be relieved.

以上、本発明の実施例を図面により詳述したが、本発明の具体的な構成はこの実施例に限られるものではなく、本発明の要旨を逸脱しない範囲の設計の変更等があっても本発明に含まれる。   The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

図１は可変容量型ポンプを示す断面図である。FIG. 1 is a sectional view showing a variable displacement pump. 図２は図１のII−II線に沿う断面図である。FIG. 2 is a sectional view taken along line II-II in FIG. 図３は切換弁を示し、（Ａ）は断面図、（Ｂ）は要部拡大図である。3A and 3B show a switching valve, in which FIG. 3A is a cross-sectional view and FIG. 図４は切換弁の移動状態を示し、（Ａ）は無負荷時を示す断面図、（Ｂ）は負荷発生時又は中回転時を示す断面図、（Ｃ）は高回転時を示す断面図ある。4A and 4B show the moving state of the switching valve, where FIG. 4A is a cross-sectional view showing no load, FIG. 4B is a cross-sectional view showing when the load is generated or during medium rotation, and FIG. is there.

符号の説明Explanation of symbols

１０ 可変容量型ポンプ
１１ ポンプケーシング
１２ ポンプ軸
１３ ロータ
１６ 溝
１７ ベーン
１９ アダプタリング
２０ 嵌装孔
２２ カムリング
２３ ポンプ室
２５Ａ 吸込通路（ポンプ吸込側通路）
２７ 吐出ポート
２８Ｂ 吐出通路（ポンプ吐出側通路）
２８Ｃ 連通路
４０ 吐出流量制御装置
４１ 第１流体圧室
４２ 第２流体圧室
５８ 主絞り
６０ 切換弁装置
６１ 連絡路
６４Ａ 弁体
６６Ａ 加圧室
６６Ｃ ドレン室
１０１ 第１ランド部
１０２ 第２ランド部
１０３ 環状溝 DESCRIPTION OF SYMBOLS 10 Variable displacement pump 11 Pump casing 12 Pump shaft 13 Rotor 16 Groove 17 Vane 19 Adapter ring 20 Fit hole 22 Cam ring 23 Pump chamber 25A Suction passage (pump suction side passage)
27 Discharge port 28B Discharge passage (pump discharge side passage)
28C Communication path 40 Discharge flow rate control device 41 First fluid pressure chamber 42 Second fluid pressure chamber 58 Main throttle 60 Switching valve device 61 Communication path 64A Valve body 66A Pressure chamber 66C Drain chamber 101 First land portion 102 Second land portion 103 annular groove

Claims (3)

ポンプケーシングに挿入されるポンプ軸に固定して回転駆動されるとともに、多数のベーンを溝に収容して半径方向に移動可能としてなるロータと、
ポンプケーシング内の嵌装孔に嵌装され、ロータの外周部との間にポンプ室を形成するとともに、ポンプケーシング内で移動変位可能とされ、ポンプケーシングとの間に第１と第２の流体圧室を形成するカムリングと、第１流体圧室にポンプ吐出側通路に設けた主絞りの上流側の圧力を導入し、第２流体圧室に該主絞りの下流側の圧力を導入する吐出流量制御装置とを有し、
吐出流量制御装置が、主絞りの上、下流側の圧力差によって作動し、ポンプ室からの圧力流体の吐出流量に応じて第１流体圧室への供給流体圧を制御する切換弁装置を有し、
切換弁装置が、主絞りの上流側に連通する加圧室を、第１流体圧室に接続された連絡路に対して開閉する弁体を有してなる可変容量型ポンプにおいて、
切換弁装置の弁体は、加圧室を上記連絡路に対して開閉する第１ランド部と、該連絡路をポンプ吸込側通路に連通する第２ランド部とを備え、更に第１ランド部と第２ランド部の間の全周に渡って設けられる環状溝を備えることを特徴とする可変容量型ポンプ。 A rotor that is fixed to a pump shaft inserted into a pump casing and is rotationally driven, and a large number of vanes are accommodated in grooves and movable in a radial direction,
It is fitted in a fitting hole in the pump casing, forms a pump chamber with the outer periphery of the rotor, and is movable and displaceable in the pump casing, and the first and second fluids between the pump casing A cam ring that forms a pressure chamber, and a discharge that introduces pressure upstream of the main throttle provided in the pump discharge side passage into the first fluid pressure chamber and introduces pressure downstream of the main throttle into the second fluid pressure chamber A flow control device,
The discharge flow rate control device is operated by a pressure difference between the upstream and downstream sides of the main throttle, and has a switching valve device that controls the supply fluid pressure to the first fluid pressure chamber according to the discharge flow rate of the pressure fluid from the pump chamber. And
In the variable displacement pump in which the switching valve device has a valve body that opens and closes the pressurizing chamber communicating with the upstream side of the main throttle with respect to the communication path connected to the first fluid pressure chamber.
The valve body of the switching valve device includes a first land portion that opens and closes the pressurizing chamber with respect to the communication path, and a second land portion that communicates the communication path with the pump suction side passage, and further includes a first land portion. A variable displacement pump comprising an annular groove provided over the entire circumference between the first land portion and the second land portion. 請求項１に記載の第２ランド部が第１ランド部より小外径をなす可変容量型ポンプ。   A variable displacement pump in which the second land portion according to claim 1 has a smaller outer diameter than the first land portion. 請求項１に記載の可変容量型ポンプを用いた自動車用油圧パワーステアリング装置。   A hydraulic power steering apparatus for an automobile using the variable displacement pump according to claim 1.
JP2005315274A 2005-10-28 2005-10-28 Variable displacement pump Expired - Fee Related JP4739912B2 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000161249A (en) * 1998-11-27 2000-06-13 Kayaba Ind Co Ltd Variable displacement type vane pump
JP2000170668A (en) * 1998-12-07 2000-06-20 Bosch Braking Systems Co Ltd Variable delivery pump
JP2000249078A (en) * 1999-02-25 2000-09-12 Kayaba Ind Co Ltd Variable displacement vane pump
JP2002098060A (en) * 2000-07-17 2002-04-05 Unisia Jkc Steering System Co Ltd Variable displacement pump
JP2005042674A (en) * 2003-07-25 2005-02-17 Unisia Jkc Steering System Co Ltd Variable displacement pump

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000161249A (en) * 1998-11-27 2000-06-13 Kayaba Ind Co Ltd Variable displacement type vane pump
JP2000170668A (en) * 1998-12-07 2000-06-20 Bosch Braking Systems Co Ltd Variable delivery pump
JP2000249078A (en) * 1999-02-25 2000-09-12 Kayaba Ind Co Ltd Variable displacement vane pump
JP2002098060A (en) * 2000-07-17 2002-04-05 Unisia Jkc Steering System Co Ltd Variable displacement pump
JP2005042674A (en) * 2003-07-25 2005-02-17 Unisia Jkc Steering System Co Ltd Variable displacement pump

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