JPS59162309A - Valve operation switching device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enhance reliability of operation of an arranement, in which a direction selector valve of an oil-hydraulic passage to make switching of valve operation is locked by a stopper as well as pressed in the direction of switching to the next one using oil pressure, by performing switching of a pilot valve after completion of locking. CONSTITUTION:Actuators 13, 14 are driven in accordance with the oil pressure fed from a direction selector valve 7, and the valve operation is switched by motion of locker arms 11, 12. After being switched, this direction selector valve 7 is locked by a stopper 20, and thereafter pressed in the direction of switching into the next one. Switching of the operation is made in synchronization with the rotation of cam shaft 17 and commenced by the actuation of a stopper release device 8. The pilot valve 6 is actuated after completion of locking of said stopper 20 at all times when a signal oil-hydraulic control valve 31 furnished in a signal oil-hydraulic supply passage 30 is put in service, that will ensure performance with high reliability.

Description

【発明の詳細な説明】 く技術分野〉 本発明は多気筒内燃機関の一部の気筒の燃焼を機関運転
条件により休止させる気筒数制御に際して稼働、休止の
切換えが行われる気筒の吸気弁及び排気弁の弁作動を切
換える弁作動切換装置に関する。Detailed Description of the Invention [Technical Field] The present invention relates to intake valves and exhaust valves of cylinders that are switched between operation and deactivation during cylinder number control in which combustion in some cylinders of a multi-cylinder internal combustion engine is deactivated depending on engine operating conditions. The present invention relates to a valve operation switching device that switches the operation of a valve.

〈従来技術〉 自動車等の車両が加速時、登板時のように高出力が要求
される状態で走行する場合は、機関の全ての気筒に混合
気を充填し、高出力を得るのがよいが、低負荷時でもそ
のまま全ての気筒を稼働させていると、各気筒の新気の
充填率が低下する結果、燃焼が悪化すると共にポンピン
グロスが増大する。そこで、低負荷時に一部の気筒の稼
働を停止することにより、混合気を残りの気筒に集中さ
せて燃焼を改善し、ボンピングロスを減少させて燃費を
向上させようとする気筒数制御システムが提案されてい
る。<Prior art> When a vehicle such as a car runs in a state where high output is required, such as when accelerating or climbing, it is better to fill all cylinders of the engine with air-fuel mixture to obtain high output. If all cylinders are operated as they are even under low load, the filling rate of fresh air in each cylinder will decrease, resulting in poor combustion and increased pumping loss. Therefore, by stopping the operation of some cylinders during low loads, a cylinder number control system is designed to improve combustion by concentrating the air-fuel mixture in the remaining cylinders, reducing pumping losses, and improving fuel efficiency. Proposed.

この種の装置として本願出願人により出願法の特願昭５
７−２３３５９３号に記載されたものの概要を第１図に
基づいて説明する。図においてカム１によって昇降駆動
されるオイルポンプ２によりオイルギヤラリからチェッ
ク弁３を介して吸入された油がチェック弁４を介してア
キュームレータ５の油圧室５ａ、パイロット弁６の入力
側ポートＰ　ｏ、方向切換弁７の入力側ポー）Ｐ＋及び
タイミングリフタ８の油圧室８ａに夫々供給される。As a device of this kind, the applicant filed a patent application in 1973.
The outline of what is described in No. 7-233593 will be explained based on FIG. In the figure, oil is sucked from an oil gear gallery via a check valve 3 by an oil pump 2 that is driven up and down by a cam 1, and is then transferred via the check valve 4 to a hydraulic chamber 5a of an accumulator 5, and to an input port P o of a pilot valve 6. It is supplied to the input port (P+) of the switching valve 7 and the hydraulic chamber 8a of the timing lifter 8, respectively.

今、吸気弁９．排気弁１０を備え稼働、休止が切換可能
な気筒が稼働状態にある時は方向切換弁７は図示の位置
にセントされており、入力側ポートＰから出力側ポー）
Ａ＋を介し′て同気筒の吸・排気弁駆動用ロッカアーム
１１．１２を両側から挟持する一方の油圧アクチュエー
タ１３の油圧室１３ａに油圧が導入され、他方の油圧ア
クチュエータ１４の油圧。Now intake valve 9. When the cylinder equipped with the exhaust valve 10 and capable of being switched between operation and rest is in operation, the directional control valve 7 is in the position shown in the figure, and the cylinder is moved from the input side port P to the output side port).
Hydraulic pressure is introduced into the hydraulic chamber 13a of one hydraulic actuator 13 that sandwiches the intake/exhaust valve drive rocker arms 11, 12 of the same cylinder from both sides via A+, and the hydraulic pressure of the other hydraulic actuator 14 is introduced.

室１４ａの油が出力側ポートＢ＋、戻り側ポートＲ及び
リリーフバルブ１５を介してオイルタンク１６に戻され
る。従って油圧アクチュエータ１３のプランジャが図中
左方向に突出ストロークして吸排気弁用ロッカアーム１
１．１２は夫々図示の位置にセントされる。そして、こ
の状態でこれらロッカアーム１１、１２はカムシャフト
１７に形成された稼働用カム１７ａ、１７ｂと係合して
駆動され、同気筒が稼働される。The oil in the chamber 14a is returned to the oil tank 16 via the output side port B+, the return side port R, and the relief valve 15. Therefore, the plunger of the hydraulic actuator 13 makes a protruding stroke to the left in the figure, causing the rocker arm 1 for the intake and exhaust valves to move forward.
1.12 are respectively placed at the positions shown. In this state, these rocker arms 11 and 12 are engaged with and driven by operating cams 17a and 17b formed on the camshaft 17, and the same cylinder is operated.

ここでパイロット弁６は方向切換弁７の出力側ポートＡ
！及びオリフィス１８を介して室ａｎに導かれる油圧Ｘ
の方が同じく出力側ポー）Ｂ＋及びオリフィス１９を介
して室ｂｏに導かれる油圧Ｙより大きいので、パイロッ
ト弁６は図示の如く弁体が右方向に移動した位置にセッ
トされ、これに伴い方向切換弁７の室ｂ１へ油圧を作用
させるため、方向切換弁７は図中左方向へ移動しようと
するが、この状態で方向切換弁７に形成された一対の溝
７ａ。Here, the pilot valve 6 is the output side port A of the directional control valve 7.
! and the hydraulic pressure X guided through the orifice 18 into the chamber an
is larger than the hydraulic pressure Y guided to the chamber bo via the output side port B+ and the orifice 19, so the pilot valve 6 is set to the position where the valve body moves to the right as shown in the figure, and the direction changes accordingly. In order to apply hydraulic pressure to the chamber b1 of the switching valve 7, the directional switching valve 7 tries to move to the left in the figure.

７ｂのうち図中左側の溝７ａと係合するストッパ２０に
より阻止される。ここで、ストッパ２０は支軸２１に揺
動自由に軸支され一端部が溝？ａ、？ｂと係合する方向
にスプリング（図示せず）によって付勢されると共に、
他端部が後述する伝動レバー２４に係合している。This is prevented by a stopper 20 that engages with the groove 7a on the left side in the figure of the groove 7b. Here, the stopper 20 is rotatably supported on a support shaft 21, and one end has a groove. a,? biased by a spring (not shown) in the direction of engagement with b;
The other end engages with a transmission lever 24, which will be described later.

この状態から運転条件の変化例えば負荷の減少が検出さ
れると図示しない制御回路により電磁式方向切換弁２２
が通電を断たれて図中左方向へ移動する。これにより油
圧クラッチ羽の両側の室ａ２゜ｂ２に導かれる油圧Ｘ、
Ｙが切り換えられ室ｂ２に高圧側の油圧Ｘが導かれてピ
ストン２３ａ及びこれに軸支された伝動レバー２４が図
中左方向に移動し、伝動レバーＵとタイミングリフタ８
の出力口・７ド８ａとが係合可能な状態となる。When a change in operating conditions, such as a decrease in load, is detected from this state, a control circuit (not shown) causes the electromagnetic directional control valve 22 to
is de-energized and moves to the left in the figure. As a result, the hydraulic pressure X is guided to the chambers a2 and b2 on both sides of the hydraulic clutch vane,
Y is switched and the high pressure side oil pressure X is guided to the chamber b2, and the piston 23a and the transmission lever 24 pivotally supported by the piston 23a move to the left in the figure, and the transmission lever U and the timing lifter 8
The output port 7 door 8a is in a state where it can be engaged.

一方タイミングリフタ８はオイルポンプ２の吐出側圧力
を受けてピストン８ｂ及び出力ロソド８Ｃが往復動する
。具体的にはカム１の位相の設定により稼働、休止の切
換が行われる気筒の吸気弁の通常のリフトが終了するタ
イミングにおいて、出力ロット８Ｃが突出し、伝動レバ
ー２４を介してストッパ２０を回動することによりスト
ッパ２０と溝７ａとの係合を解除する。ストッパ２０が
解除されるとバイロフト弁６からの信号油圧により方向
切換弁７が図中左方向に切換移動する。On the other hand, in the timing lifter 8, a piston 8b and an output rod 8C reciprocate in response to the pressure on the discharge side of the oil pump 2. Specifically, at the timing when the normal lift of the intake valve of the cylinder whose operation and deactivation are switched by setting the phase of the cam 1 ends, the output rod 8C protrudes and rotates the stopper 20 via the transmission lever 24. By doing so, the engagement between the stopper 20 and the groove 7a is released. When the stopper 20 is released, the signal hydraulic pressure from the biloft valve 6 causes the directional control valve 7 to switch to the left in the figure.

方向切換弁７が切り換えられると、入口側ポートＰＩと
出力側ポートＢ＋、戻り側ボートＲ＋と出力側ポートＡ
＋とが夫々連通するように切り換えるため油圧Ｙが高圧
側、油圧Ｘが低圧側となって逆転する。この結果高圧側
の油圧Ｘが油圧クラッチ羽の室ａ２に導かれるためピス
トン２３ａと共に伝動レバー２４が図中右方向に移動し
て戻され、タイミングリフタ８の出力ロット８ｃとの係
合が解除されるので、ストッパ加が切換移動後の方向切
換弁７の図中右側の溝７ｂに係合した状態でロックされ
る。When the directional switching valve 7 is switched, the inlet side port PI and the output side port B+, the return side boat R+ and the output side port A
+ are switched so that they communicate with each other, so the oil pressure Y becomes the high pressure side and the oil pressure X becomes the low pressure side, so that they are reversed. As a result, the high pressure side hydraulic pressure X is guided to the chamber a2 of the hydraulic clutch vane, so the transmission lever 24 is moved back to the right in the figure together with the piston 23a, and the engagement with the output rod 8c of the timing lifter 8 is released. Therefore, the stopper is locked in a state in which it is engaged with the groove 7b on the right side in the figure of the directional control valve 7 after the switching movement.

そして、方向切換弁７が切換ねった状態ではアキューム
レータ５の油圧室５ａからの油圧が方向切換弁７の出力
側ポートＢ＋を介して油圧アクチュエータ１４の油圧室
１４ａに供給されると共に、油圧アクチュエータ１３の
油圧室１３ａ内の油は戻り側ポートＲ１を介してオイル
タンク１６に戻される。When the directional control valve 7 is not switched, the hydraulic pressure from the hydraulic chamber 5a of the accumulator 5 is supplied to the hydraulic chamber 14a of the hydraulic actuator 14 via the output side port B+ of the directional control valve 7, and the hydraulic pressure is supplied to the hydraulic chamber 14a of the hydraulic actuator 14. The oil in the hydraulic chamber 13a is returned to the oil tank 16 via the return side port R1.

ここにおいて、吸気弁９及び排気弁１０が共にロッカア
ーム１１．１２と稼働用カム１７ａ、１７ｂとの接触面
にクリアランスがある時に、油圧室１４ａに供給された
油圧により油圧アクチュエータ１４のプランジャが図中
右方向に突出ストロークし、ロッヵア−４１１，１２を
同方向に移動させて休止用カム１７０゜１７ｄと係合さ
せこの気筒の運転を休止させまた、油圧Ｘと油圧Ｙとの
逆転により高圧側の油圧Ｙがオリフィス１９に通じてパ
イロット弁６の室ｂｏに除々に導入されるので方向切換
弁７の切換完了後弁体が図中左方向へ移動し、これによ
りパイロット弁６からの信号油圧が方向切換弁７を次回
の切換方向に付勢するように作用する。Here, when there is clearance between the contact surfaces of both the intake valve 9 and the exhaust valve 10 with the rocker arm 11.12 and the operating cams 17a and 17b, the plunger of the hydraulic actuator 14 is moved by the hydraulic pressure supplied to the hydraulic chamber 14a as shown in the figure. A projecting stroke is made to the right, moving the rocker gears 411 and 12 in the same direction and engaging the stop cams 170 and 17d to stop the operation of this cylinder. Since the hydraulic pressure Y is gradually introduced into the chamber bo of the pilot valve 6 through the orifice 19, the valve body moves to the left in the figure after the switching of the directional control valve 7 is completed, and as a result, the signal hydraulic pressure from the pilot valve 6 is It acts to bias the directional switching valve 7 in the next switching direction.

しかしながら、このような従来の弁作動切換装置にあっ
ては、稼働、休止の切換時、方向切換弁がストッパで切
換位置にロックされる前にバイロフト弁が切り換わって
油圧が逆転することを防止するためオリフィスによって
バイロフト弁の切換速度を規制しているが、オリフィス
による絞り効果は加工精度のバラツキによって変り、又
、機関低速時でも充分パイロット弁の切換時間に余裕を
もたせるべくオリフィスの通路断面積を小さくすると、
高速時においてはオイルポンプの回転速度増大によりア
キュームレータへ再度部が充填される時間が短縮するに
も拘わらず、オリフィスの絞り効果が増大してパイロッ
ト弁の相対的な切換時間遅れが大きくなるため、切換動
作を再開する時間が遅れる。However, in such a conventional valve operation switching device, when switching between operation and rest, the biloft valve is switched before the directional control valve is locked in the switching position by the stopper, which prevents the hydraulic pressure from reversing. To achieve this, the switching speed of the viroft valve is regulated by an orifice, but the throttling effect of the orifice changes depending on variations in machining accuracy, and the passage cross-sectional area of the orifice is adjusted to allow sufficient margin for the pilot valve switching time even when the engine is at low speed. If you reduce ,
At high speeds, although the time it takes for the accumulator to refill is shortened due to the increased rotational speed of the oil pump, the throttling effect of the orifice increases and the relative switching time delay of the pilot valve increases. The time to restart the switching operation is delayed.

また、逆にオリフィスの通路断面積を大きくし過ぎると
、今度はパイロット弁の切り換わりが早過ぎてストッパ
によるロックが完了する前に逆転した油圧によって方向
切換弁が逆戻りし、周期的にこれを繰り返す発振現象が
生じる。On the other hand, if the cross-sectional area of the orifice passage is made too large, the pilot valve will switch too quickly and the reversed hydraulic pressure will cause the directional control valve to return to its original position before the stopper completes locking. Repeated oscillation phenomenon occurs.

このためオリフィスの加工精度が要求され、塵埃等によ
ってオリフィスの径が実質的に小さくなるとシステムの
作動に大きな影響が出てくるという問題があった。For this reason, precision in machining the orifice is required, and there is a problem in that if the diameter of the orifice becomes substantially reduced due to dust or the like, the operation of the system will be greatly affected.

〈発明の目的〉 本発明はこのような従来の問題点に鑑みなされたもので
、方向切換弁のストッパによるロックが完了してからパ
イロット弁作動用の信号油圧供給ｊＪｌ路を開くことに
より方向切換弁の切換途中での逆戻りを確実に防止した
上で、機関高速時においても可及的にバイロフト弁の切
換速度を増大させて気筒の稼働、休止の切換動作を迅速
に再開できるようにして上記問題点を解決することを目
的とする。<Purpose of the Invention> The present invention has been made in view of the above-mentioned conventional problems.The present invention has been made in view of the above-mentioned problems in the prior art. After reliably preventing reversal during valve switching, the switching speed of the viroft valve is increased as much as possible even when the engine is at high speed, so that switching operation between cylinder operation and deactivation can be resumed quickly. The purpose is to solve problems.

〈発明の構成〉 このため、本発明ではパイロット弁を作動させる油圧連
路にオリフィスの代りにストッパの作動に応動して開閉
しストッパのロック操作が完了したことト感知して閉か
ら開に切り換えわる信号油圧制御弁を設けた構成として
上記目的を達成する。<Structure of the Invention> For this reason, in the present invention, instead of an orifice in the hydraulic communication line for operating the pilot valve, the hydraulic line opens and closes in response to the operation of the stopper, and switches from closed to open upon sensing that the locking operation of the stopper is completed. The above object is achieved by a configuration in which a signal hydraulic pressure control valve is provided.

〈実施例〉 以下に本発明の実施例を示す。一実施例の全体構成を示
す第２図において、基本的な油圧回路の構成は従来と同
様であり、第１図と同一の構成部分は同一符号を付しで
あるが、本発明ではパイロット弁６の室ａｏ、ｂｏと方
向切換弁７の出力側ボー・トＡ＋、Ｂ＋とを結ぶパイロ
ット弁６作動用の信号油圧供給通路３０の途中にストッ
パ２０の作動に応動して開閉動作する信号油圧制御弁３
１を設ける。但し、パイロット弁６の切換に先立って行
われるストッパ２０の作動に支障を与えないように、信
号油圧制御弁３１は、前記信号油圧供給通路３０の電磁
式方向切換弁２２に油圧を供給する通路との分岐点とパ
イロット弁６の一方の室（実施例では室ｂｏ）とを結ぶ
通路の途中に設ける。<Example> Examples of the present invention are shown below. In FIG. 2 showing the overall configuration of one embodiment, the basic configuration of the hydraulic circuit is the same as the conventional one, and the same components as in FIG. 1 are given the same reference numerals. A signal hydraulic pressure for opening and closing in response to the operation of the stopper 20 is installed in the middle of the signal hydraulic pressure supply passage 30 for operating the pilot valve 6 which connects the chambers ao, bo of 6 and the output boats A+, B+ of the directional control valve 7. control valve 3
1 will be provided. However, in order not to interfere with the operation of the stopper 20 that is performed prior to switching the pilot valve 6, the signal hydraulic pressure control valve 31 is connected to a passage that supplies hydraulic pressure to the electromagnetic directional control valve 22 of the signal hydraulic pressure supply passage 30. It is provided in the middle of a passage connecting the branch point with one chamber (chamber bo in the embodiment) of the pilot valve 6.

第３図は、信号油圧制御弁３１及びその周辺部の詳細な
構成を示したものである。図において、信号油圧制御弁
３１は方向切換弁７を嵌挿するシリンダ３２に方向切換
弁７の移動方向と直角方向に形成された穴３２ａに摺動
自由に嵌挿される。又、信号油圧制御弁３１は袋状に内
部がくり抜いて形成されており、シリンダ３２の穴３２
ａの端壁と信号油圧制御弁３１のくり抜き穴ａＬａ内の
端壁とに両端を係止したリターンスプリング３３により
信号油圧制御弁３〕の穴３２ａから突出する端面がスト
ッパ２０の一端部に係合し、て該ストッパ２０の他端部
を方向切換弁７の溝７ａ又は７ｂに係合する方向に付勢
している。さらにＬ字形の伝動レバー２４がストッパ２
０を挾んで信号油圧制御弁３１の反対側に取り付けられ
、油圧クラッチ詔の接続時タイミングリフタ８の出力ロ
ット８Ｃが第３図で上方にストロークすると、伝動レバ
ー２４は図中反時計回りに回動し、スレンバ２０をリタ
ーンスプリング３３の付勢力に抗して図中時計回りに回
動させて溝７ａ又は７ｂとの保合を解除させるようにな
っている。FIG. 3 shows the detailed configuration of the signal oil pressure control valve 31 and its surroundings. In the figure, the signal oil pressure control valve 31 is slidably inserted into a hole 32a formed in a cylinder 32 into which the directional switching valve 7 is inserted, in a direction perpendicular to the moving direction of the directional switching valve 7. Further, the signal hydraulic pressure control valve 31 is formed by hollowing out the inside in a bag shape, and the hole 32 of the cylinder 32 is hollowed out.
The end surface protruding from the hole 32a of the signal hydraulic control valve 3 is engaged with one end of the stopper 20 by the return spring 33 whose both ends are engaged with the end wall of a and the end wall of the hollow hole aLa of the signal hydraulic control valve 31. The other end of the stopper 20 is urged in the direction of engagement with the groove 7a or 7b of the directional control valve 7. Furthermore, the L-shaped transmission lever 24 is connected to the stopper 2.
When the output rod 8C of the timing lifter 8 strokes upward in FIG. 3 when the hydraulic clutch lever is connected, the transmission lever 24 rotates counterclockwise in the diagram. The lever 20 is rotated clockwise in the figure against the biasing force of the return spring 33 to release the engagement with the groove 7a or 7b.

そして、前記パイロット弁６の室ｂｏに至る信号油圧供
給通路３０の途中を穴３２ａに開口するボー）３２ｂ、
３２Ｃに接続し、この２つのポート３２ｂ。and a hole 32b that opens into a hole 32a in the middle of the signal oil pressure supply passage 30 leading to the chamber bo of the pilot valve 6;
32C, and these two ports 32b.

３２Ｃを信号油圧制御弁３１の外周壁に形成した環状溝
３１ｂによって連通、遮断することにより信号油圧制御
通路３０を開閉するようになっている。32C is communicated with and interrupted by an annular groove 31b formed on the outer circumferential wall of the signal oil pressure control valve 31, thereby opening and closing the signal oil pressure control passage 30.

次に作用を説明する。ストッパ２０が方向切換弁７の溝
７ａに係合している状態では、信号油圧制御弁３１の環
状溝３１ｂによりポート３２ｂ、３２Ｃ相互は連通して
おり、信号油圧供給通路３０は開かれているため油圧ア
クチュエータ１４の油室１４ａの油圧がパイロット弁６
の室ｂｏに入力されている。この状態で、電磁式方向切
換弁２２の切換作動により油圧クラッチ２３を接続に切
り換えると、タイミングリフタ８の出力ロット８ｃのス
トロークにより伝動レバー２４の回動を介してスト１．
パ加と方向切換弁７の溝７ａとの係合が解除されると同
時にストッパ２０の回動により信号油圧制御弁３１が第
３図で左方向にストロークし、環状溝３１　ｃと図中右
側のポート３２　Ｃとの連通が遮断され信号油圧供給通
路３０が閉じる。Next, the effect will be explained. When the stopper 20 is engaged with the groove 7a of the directional control valve 7, the ports 32b and 32C communicate with each other through the annular groove 31b of the signal oil pressure control valve 31, and the signal oil pressure supply passage 30 is open. Therefore, the oil pressure in the oil chamber 14a of the hydraulic actuator 14 is applied to the pilot valve 6.
It is input to room bo. In this state, when the hydraulic clutch 23 is switched to the connected state by the switching operation of the electromagnetic directional switching valve 22, the stroke of the output rod 8c of the timing lifter 8 causes the rotation of the transmission lever 24 to cause the stroke 1.
At the same time as the engagement between the brake pad and the groove 7a of the directional control valve 7 is released, the signal oil pressure control valve 31 is stroked to the left in FIG. 3 due to the rotation of the stopper 20, and the annular groove 31c and the right side The communication with the port 32C is cut off, and the signal oil pressure supply passage 30 is closed.

この間、方向切換弁７は切換前に付勢されていた油圧に
より切換方向に移動するが、ストッパ２０は切換後の溝
７ｂに係合するまでは方向切換弁７の周壁を摺接しつつ
、解除位置に保持されるので信号油圧制御弁３１も閉位
置に保持される。従って、方向切換弁７の移動終了近く
で、油圧ｘ、ｙの高低が逆転してもバイロフト弁６は依
然として切換前の位置に保持されたままである。During this time, the directional control valve 7 moves in the switching direction by the hydraulic pressure applied before switching, but the stopper 20 slides against the circumferential wall of the directional control valve 7 until it engages with the groove 7b after switching, and then is released. Since the signal oil pressure control valve 31 is held in the closed position, the signal hydraulic pressure control valve 31 is also held in the closed position. Therefore, even if the levels of the oil pressures x and y are reversed near the end of the movement of the directional switching valve 7, the biloft valve 6 is still held at the position before switching.

そして、方向切換弁７が移動を完了してストッパ２０が
切換後の溝７ｂに係合してロックされた時、始めて信号
油圧制御弁３１がリターンスプリング３３により第３図
で右方向へストロークして開位置に切り換わり信号油圧
供給通路３ｏを開通させ、逆転されている油圧によりバ
イロフト＃６を切換動作させる。Then, when the directional switching valve 7 completes its movement and the stopper 20 engages with the groove 7b after switching and is locked, the signal hydraulic pressure control valve 31 is stroked to the right in FIG. 3 by the return spring 33. The signal oil pressure supply passage 3o is switched to the open position, and the biloft #6 is operated by the reversed oil pressure.

このように、方向切換弁７が切換位置にロックサレタ後
ハイロット弁６が切換動作するため、これにより方向切
換弁７０室ａｌ＋ｂ＋の油圧が次回の切換方向に切り換
えられても方向切換弁７が逆戻りすることを確実に防止
できる。In this way, after the directional control valve 7 is locked in the switching position, the high lot valve 6 switches, so even if the oil pressure in the directional control valve 70 chambers al+b+ is switched to the next switching direction, the directional control valve 7 will not return to the reverse position. This can definitely be prevented.

そして、このように安全性を確保できるため、信号油圧
制御弁３１開時の信号油圧供給通路３ｏの通路断面積を
充分大きく採ってパイロット弁６の切換動作を可及的に
速めることができ、高速時における切換再開時間を短縮
することができる。Since safety can be ensured in this way, the cross-sectional area of the signal hydraulic pressure supply passage 3o when the signal hydraulic pressure control valve 31 is open can be made sufficiently large to speed up the switching operation of the pilot valve 6 as much as possible. The switching restart time at high speed can be shortened.

また、加工精度が要求される２つのオリフィスが不要と
なり、目詰りによる悪影響も解消できると共に、簡単な
構造の信号油圧制御弁３１を設けるだけでよいからコス
ト的にも有利である。Further, two orifices that require high processing accuracy are not required, and the adverse effects caused by clogging can be eliminated, and it is also advantageous in terms of cost because it is only necessary to provide the signal hydraulic pressure control valve 31 with a simple structure.

尚、前記したように方向切換弁７の移動終了近くで油圧
Ｘ、Ｙが逆転し、この時点で油圧クラッチ器の接続が解
除されるのでストッパ２ｏが溝７ｂに係合した後ロック
が解除されることはない。As mentioned above, the oil pressures X and Y are reversed near the end of the movement of the directional control valve 7, and at this point the hydraulic clutch is disconnected, so the lock is released after the stopper 2o engages with the groove 7b. It never happens.

（発明の効果〉 以上説明したよう、本発明によれば、方向切換弁を次回
の切換方向に付勢する油圧を導くためのパイロット弁を
作動させる信号油圧供給通路に、方向切換弁をロックす
るストッパの作動に応動し、ロック動作完了により閉か
ら開に切り換わる信号油圧制御弁を設けた構成としたた
め、パイロット弁の過早切換による方向切換弁の切換途
中の戻りを確実に防止した上でパイロット弁の切換動作
を可及的に速めることができ、もって高速時での切換再
開時間を短縮して応答性を向上できると共に、目詰りの
問題も解消されて信頼性も向上でき、しかも信号油圧制
御弁は簡単な構成で済むためコスト的にも有利である等
種々の優れた特長を備えるものである。(Effects of the Invention) As described above, according to the present invention, the directional control valve is locked in the signal hydraulic pressure supply passage that operates the pilot valve for guiding the hydraulic pressure that biases the directional control valve in the next switching direction. The structure is equipped with a signal hydraulic control valve that responds to the operation of the stopper and switches from closed to open when the locking operation is completed, which reliably prevents the directional control valve from returning during switching due to premature switching of the pilot valve. The switching operation of the pilot valve can be made as fast as possible, which shortens the switching restart time at high speeds and improves responsiveness.The problem of clogging is also eliminated, improving reliability. Hydraulic control valves have various excellent features such as being simple in construction and cost-effective.

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

第１図は従来の内燃機関の弁作動切換装置の一例を示す
油圧回路図、第２図は本発明の一実施例に係る内燃機関
の弁作動切換装置を示す油圧回路図、第３図は同上実施
例の要部拡大図である。 ６・・・パイロット弁　　７・・・方向切換弁８・・・
タイミングリフタ　　９・・・吸気弁１０・・・排気弁
　　１１・・・吸気弁開閉用ロッカアーム１２・・・排
気弁開閉用ロッカアーム　　１３．１４・・・油圧アク
チュエータ　　１７ａ、１７ｂ・・・稼働用カム１７ｃ
、１７ｄ・・・休止用カム　　２０・・・ストッパ２２
・・・電磁式方向切換弁　　２３・・・油圧クラッチ２
４・・・伝動レバー　　３０・・・信号油圧供給通路３
１・・・信号油圧制御弁 特許出願人　　日産自動車株式会社 代理人　　弁理士　笹　島　冨二雄FIG. 1 is a hydraulic circuit diagram showing an example of a conventional valve operation switching device for an internal combustion engine, FIG. 2 is a hydraulic circuit diagram showing a valve operation switching device for an internal combustion engine according to an embodiment of the present invention, and FIG. 3 is a hydraulic circuit diagram showing an example of a conventional valve operation switching device for an internal combustion engine. It is an enlarged view of the main part of the same embodiment as above. 6... Pilot valve 7... Directional switching valve 8...
Timing lifter 9...Intake valve 10...Exhaust valve 11...Rocker arm for opening and closing the intake valve 12...Rocker arm for opening and closing the exhaust valve 13.14...Hydraulic actuator 17a, 17b...Cam for operation 17c
, 17d...Stopping cam 20...Stopper 22
...Solenoid directional control valve 23...Hydraulic clutch 2
4...Transmission lever 30...Signal oil pressure supply passage 3
1...Signal hydraulic control valve patent applicant Nissan Motor Co., Ltd. agent Patent attorney Fujio Sasashima

Claims (1)

【特許請求の範囲】[Claims] 機関運転条件に応じロッカアームをロッカシャフトの軸
方向に移動させて、カムシャフトの軸方向に並設したプ
ロフィルの異なる一対のカムのいずれか一方と選択的に
係合させることにより、このロッカアームを介して駆動
される吸・排気弁の弁作動を切換えるようにした内燃機
関の弁作動切換装置において、ロッカアームを移動させ
るための油圧アクチュエータを設け、この油圧アクチュ
エータと油圧供給通路及び油圧戻し通路とを方向切換弁
を介して接続する一方、この方向切換弁を切換位置にロ
ックするストッパと、機関運転条件の変化によりカムシ
ャフトの回転に同期したタイミングで前記ストッパを解
除するストッパ解除装置と、前記方向切換弁を切換作動
後に次回の切換方向に付勢する油圧を供給するバイロフ
ト弁を設けると共に、前記ストッパの作動に応動じスト
ッパのロック動作完了時閉から開に切り換える信号油圧
制御弁をパイロット弁作動用の信号油圧供給通路に介設
したことを特徴とする内燃機関の弁作動切換装置。By moving the rocker arm in the axial direction of the rocker shaft depending on the engine operating conditions and selectively engaging one of a pair of cams with different profiles arranged in parallel in the axial direction of the camshaft, the rocker arm can be moved through the rocker arm. In a valve operation switching device for an internal combustion engine that switches the valve operation of intake and exhaust valves driven by a stopper that is connected via a switching valve and locks the directional switching valve in the switching position; a stopper release device that releases the stopper at a timing synchronized with the rotation of the camshaft due to a change in engine operating conditions; A biloft valve is provided to supply hydraulic pressure to urge the valve in the next switching direction after the valve is switched, and a signal hydraulic control valve is provided for operating the pilot valve, which responds to the operation of the stopper and switches from closed to open when the locking operation of the stopper is completed. A valve operation switching device for an internal combustion engine, characterized in that it is installed in a signal oil pressure supply passage.