EP0185570B1 - Single rocker arrangement for driving two valves - Google Patents

Single rocker arrangement for driving two valves Download PDF

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Publication number
EP0185570B1
EP0185570B1 EP19850402230 EP85402230A EP0185570B1 EP 0185570 B1 EP0185570 B1 EP 0185570B1 EP 19850402230 EP19850402230 EP 19850402230 EP 85402230 A EP85402230 A EP 85402230A EP 0185570 B1 EP0185570 B1 EP 0185570B1
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EP
European Patent Office
Prior art keywords
rocker
valves
rods
boss
cam
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19850402230
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German (de)
French (fr)
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EP0185570A1 (en
Inventor
Roger Lombard
Original Assignee
Automobiles Peugeot SA
Automobiles Citroen SA
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Publication of EP0185570A1 publication Critical patent/EP0185570A1/en
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Publication of EP0185570B1 publication Critical patent/EP0185570B1/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/181—Centre pivot rocking arms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
    • F01L1/262—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder with valve stems disposed radially from a centre which is substantially the centre of curvature of the upper wall surface of a combustion chamber
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/24—Cylinder heads
    • F02F1/42—Shape or arrangement of intake or exhaust channels in cylinder heads
    • F02F1/4214—Shape or arrangement of intake or exhaust channels in cylinder heads specially adapted for four or more valves per cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/24—Cylinder heads
    • F02F2001/244—Arrangement of valve stems in cylinder heads
    • F02F2001/245—Arrangement of valve stems in cylinder heads the valve stems being orientated at an angle with the cylinder axis
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87265—Dividing into parallel flow paths with recombining
    • Y10T137/8741—With common operator
    • Y10T137/87491—Mechanical movement between actuator and non-rotary valve

Definitions

  • the invention relates to devices used in certain internal combustion engines for simultaneously actuating two stem valves by means of a single rocker arm.
  • the rocker arm pivots about an axis roughly orthogonal to the two rods and is supported on the end face of each of them by two bosses located respectively at the end of two juxtaposed arms of the rocker arm. So that the support of each boss on the associated rod takes place properly when the rocker rocker oscillates, said end face being flat and perpendicular to the axis of the rod, the cooperating face of the boss is curved, generally in the form of a spherical cap. .
  • Each valve is pushed towards the corresponding boss by a spring which tends to apply the head of the valve on a seat delimiting an intake or exhaust duct, and the rocker arm oscillates under the action of a rotary cam whose contour , fitted with a circular portion and a lobe, acts on the rocker arm directly or via a sliding plunger.
  • a backlash device is provided between the rocker arm and the cam or in line with the axis of the rocker arm, but then, due to the manufacturing tolerances of the rocker arm, the valves and the parts which support them, unless carry out an expensive matching of parts or an adjustment by shim, the operating clearance is eliminated only for one of the valves; this results, for the other valve, in a loss of lift stroke and an increase in noise and wear.
  • the object of the invention is to produce, by simple and light means, a device suitable for actuating with equal or even zero operating clearances, two stem valves associated with a single rocker arm.
  • the invention therefore relates to an actuating device for two stem valves, comprising a rocker arm which is mounted oscillating on an axis and comprises on one side, an arm cooperating with a cam and, on the other side, two arms terminated by bosses in abutment, respectively, against the end of associated valve stems, characterized in that the rocker arm is slidably mounted on its axis, the transmission between the rocker arm and the cam authorizing this running, and in that at right of each boss one of the two contacting surfaces, of the boss or of the end of the rod, is curved in the shape of a substantially spherical cap, the other surface being planar or cylindrical, the two planar or cylindrical surfaces being inclined and arranged approximately symmetrically with respect to a plane perpendicular to the axis of the rocker arm.
  • rocker arm 1 which is mounted oscillating on an axis 2 carried by two bearings 3, 3a and which cooperates on one side with a cam 4 via a pusher 5 and on the other side with two valves 6, 7 with stem 8, 9.
  • the assembly is carried in the usual way by a cylinder head 10 of an internal combustion engine, the cam 4 being integral with a camshaft 11 parallel to the axis 2, and the pusher 5 sliding in a guide perpendicular to the shaft 11.
  • springs exert respectively on each of the valves a permanent axial thrust tending to place them in their closed position, position which they reach when the pusher 5 cooperates with a circular portion 4a of the cam, while that they move away from their seats by opening the associated conduits 12, 13 when the pusher 5 cooperates with a lobe 4b of the cam.
  • the rocker arm 1 is slidably mounted on the shaft 2 and a substantial space E1, E2 separates it from each bearing 3, 3a in the axial direction. It has on the side opposite to the cam 4 two arms 19, 20 at the end of each of which is formed a boss 21, 22 (FIG. 3) or 23, 24 (FIG. 4) cooperating with the end face 25a, 26a of each. rods ( Figure 4) or with a face 27a, 28a of a tip 27, 28 attached to the end 25, 26 of the corresponding rod ( Figure 3).
  • the end face 25a, 26a of the stems is curved in the shape of a spherical cap or roughly spherical, and the bosses 23, 24 cooperate with them respectively by two plane faces 23a, 24a symmetrically inclined with respect to the abovementioned plane PP.
  • these two faces 23a, 24a can alternatively be formed of cylinder portions having their respective generatrices symmetrical with respect to the plane PP.
  • the pusher 5 comprises a known device, not shown here, for taking up play tending to lengthen it when it is not subjected to a significant axial force, in particular when there appears an operating clearance between the rocker arm and the cooperating parts when the valves rest on their respective seats.
  • the take-up device can, in known manner, be interposed between the axis 2 and the cylinder head 10.
  • the pusher does not have a play take-up device but cooperates with the rocker arm by means of conventional clearance adjustment means.
  • This single adjustment means is sufficient to ensure equal operating clearances for the two valves since if these two games differed, the boss corresponding to the weakest of these games would come before the other boss in contact with the associated rod, causing as indicated above the self-centering of the rocker arm by sliding on its axis until the another boss reaches the cooperating side.
  • This arrangement has less inertia and is less expensive than those which include a means of adjustment to the right of each of the two bosses, and it ensures equality of the two operating clearances even after possible different wear of the cooperating faces since the correction by The rocker arm is always self-centering while the engine is running.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Description

L'invention est relative aux dispositifs utilisés dans certains moteurs à combustion interne pour actionner simultanément deux soupapes à tige au moyen d'un seul culbuteur.The invention relates to devices used in certain internal combustion engines for simultaneously actuating two stem valves by means of a single rocker arm.

Dans un tel agencement, décrit dans le document US-A-3 428 032, les deux tiges étant parallèles entre elles ou peu inclinées l'une par rapport à l'autre, le culbuteur pivote autour d'un axe à peu près orthogonal aux deux tiges et prend appui sur la face extrême de chacune d'elles par deux bossages situés respectivement à l'extrémité de deux bras juxtaposés du culbuteur. Pour que l'appui de chaque bossage sur la tige associée s'effectue convenablement quand le culbuteur oscille, ladite face extrême étant plate et perpendiculaire à l'axe de la tige, la face coopérante du bossage est bombée, généralement en forme de calotte sphérique.In such an arrangement, described in document US-A-3 428 032, the two rods being parallel to each other or slightly inclined with respect to each other, the rocker arm pivots about an axis roughly orthogonal to the two rods and is supported on the end face of each of them by two bosses located respectively at the end of two juxtaposed arms of the rocker arm. So that the support of each boss on the associated rod takes place properly when the rocker rocker oscillates, said end face being flat and perpendicular to the axis of the rod, the cooperating face of the boss is curved, generally in the form of a spherical cap. .

Chaque soupape est poussée vers le bossage correspondant par un ressort qui tend à appliquer la tête de la soupape sur un siège délimitant un conduit d'admission ou d'échappement, et le culbuteur oscille sous l'action d'une came rotative dont le contour, muni d'une portion circulaire et d'un lobe, agit sur le culbuteur directement ou par l'intermédiaire d'un poussoir coulissant.Each valve is pushed towards the corresponding boss by a spring which tends to apply the head of the valve on a seat delimiting an intake or exhaust duct, and the rocker arm oscillates under the action of a rotary cam whose contour , fitted with a circular portion and a lobe, acts on the rocker arm directly or via a sliding plunger.

Quand le culbuteur est en contact avec le lobe de la came, ses deux bossages poussent les deux tiges à l'encontre des ressorts, provoquant la levée des deux soupapes sur leurs sièges respectifs, donc l'ouverture des conduits correspondants. Quand le culbuteur ou le poussoir coopère avec la portion circulaire de la came, chaque soupape repose sur son siège, fermant le conduit correspondant. Pour que le contact de chaque soupape avec son siège soit bien assuré, il est prévu le plus souvent un jeu de fonctionnement réglé généralement par un moyen fileté agencé au droit de chacun des deux bossages, ce qui est relativement coûteux, encombrant et présente une inertie nuisible au fonctionnement du moteur ; en variante un dispositif de rattrapage de jeu est prévu entre le culbuteur et la came ou au droit de l'axe du culbuteur, mais alors, du fait des tolérances de fabrication du culbuteur, des soupapes et des pièces qui les supportent, à moins de procéder à un coûteux appariement de pièces ou à un ajustage par cale d'épaisseur, le jeu de fonctionnement est supprimé seulement pour l'une des soupapes; il en résulte, pour l'autre soupape, une perte de course de levée et un surcroît de bruit et d'usure.When the rocker arm is in contact with the lobe of the cam, its two bosses push the two rods against the springs, causing the lifting of the two valves on their respective seats, therefore the opening of the corresponding conduits. When the rocker or the pusher cooperates with the circular portion of the cam, each valve rests on its seat, closing the corresponding conduit. So that the contact of each valve with its seat is well ensured, an operating clearance is generally provided, generally adjusted by a threaded means arranged in line with each of the two bosses, which is relatively expensive, bulky and has inertia. detrimental to engine operation; alternatively a backlash device is provided between the rocker arm and the cam or in line with the axis of the rocker arm, but then, due to the manufacturing tolerances of the rocker arm, the valves and the parts which support them, unless carry out an expensive matching of parts or an adjustment by shim, the operating clearance is eliminated only for one of the valves; this results, for the other valve, in a loss of lift stroke and an increase in noise and wear.

L'invention a pour but de réaliser, par des moyens simples et légers, un dispositif propre à actionner avec des jeux de fonctionnement égaux, voire nuls, deux soupapes à tige associées à un seul culbuteur.The object of the invention is to produce, by simple and light means, a device suitable for actuating with equal or even zero operating clearances, two stem valves associated with a single rocker arm.

L'invention a donc pour objet un dispositif d'actionnement pour deux soupapes à tige, comprenant un culbuteur qui est monté oscillant sur un axe et comporte d'un côte, un bras coopérant avec une came et, de l'autre côte, deux bras terminés par des bossages en appui, respectivement, contre l'extrémité de tiges de soupapes associées, caractérisé en ce que le culbuteur est monté coulissant sur son axe, la transmission entre le culbuteur et la came autorisant ce courissement, et en ce que au droit de chaque bossage l'une des deux surfaces en contact, du bossage ou de l'extrémité de la tige, est bombée en forme de calotte sensiblement sphérique, l'autre surface étant plane ou cylindrique, les deux surfaces planes ou cylindriques étant inclinées et disposées de façon à peu près symétrique par rapport à un plan perpendiculaire à l'axe du culbuteur.The invention therefore relates to an actuating device for two stem valves, comprising a rocker arm which is mounted oscillating on an axis and comprises on one side, an arm cooperating with a cam and, on the other side, two arms terminated by bosses in abutment, respectively, against the end of associated valve stems, characterized in that the rocker arm is slidably mounted on its axis, the transmission between the rocker arm and the cam authorizing this running, and in that at right of each boss one of the two contacting surfaces, of the boss or of the end of the rod, is curved in the shape of a substantially spherical cap, the other surface being planar or cylindrical, the two planar or cylindrical surfaces being inclined and arranged approximately symmetrically with respect to a plane perpendicular to the axis of the rocker arm.

Suivant d'autres dispositions avantageuses de l'invention:

  • - les tiges des soupapes étant inclinées symétriquement par rapport à un plan perpendiculaire à l'axe du culbuteur, et leur surface d'extrémité (ou celle d'un embout rapporté) étant perpendiculaire à leur axe, la surface du bossage est bombée en forme de calotte sensiblement sphérique;
  • - les tiges des soupapes étant à peu près parallèles entre elles et orthogonales à l'axe du culbuteur, leur surface d'extrémité est bombée en forme de calotte sensiblement sphérique, et les surfaces respectives des deux bossages sont planes ou cylindriques;
  • - le dispositif est muni d'un seul moyen de réglage ou de rattrapage automatique du jeu de fonctionnement, par exemple associé à un poussoir interposé entre le culbuteur et la came.
According to other advantageous provisions of the invention:
  • - the valve stems being inclined symmetrically with respect to a plane perpendicular to the axis of the rocker arm, and their end surface (or that of an attached nozzle) being perpendicular to their axis, the surface of the boss is curved in shape substantially spherical cap;
  • - the valve stems being roughly parallel to each other and orthogonal to the axis of the rocker arm, their end surface is curved in the shape of a substantially spherical cap, and the respective surfaces of the two bosses are planar or cylindrical;
  • - The device is provided with a single means of automatic adjustment or adjustment of the operating clearance, for example associated with a pusher interposed between the rocker and the cam.

Deux exemples de réalisation d'un dispositif de commande selon l'invention sont décrits ci-après, avec référence aux dessins annexés parmi lesquels:

  • - La figure 1 est une vue simplifiée du dispositif selon un premier mode de réalisation, avec coupes partielles par des plans perpendiculaires à l'axe des culbuteurs ;
  • - La figure 2 en est une vue de dessus ;
  • - La figure 3 est une vue en coupe suivant la ligne 3-3 de la figure 1,
  • - et la figure 4 est une vue analogue à celle de la figure 3 pour un second mode de réalisation.
Two exemplary embodiments of a control device according to the invention are described below, with reference to the appended drawings among which:
  • - Figure 1 is a simplified view of the device according to a first embodiment, with partial sections through planes perpendicular to the axis of the rockers;
  • - Figure 2 is a top view;
  • FIG. 3 is a sectional view along line 3-3 of FIG. 1,
  • - And Figure 4 is a view similar to that of Figure 3 for a second embodiment.

On voit sur les figures un culbuteur 1 qui est monté oscillant sur un axe 2 porté par deux paliers 3, 3a et qui coopère d'un côté avec une came 4 par l'intermédiaire d'un poussoir 5 et de l'autre côté avec deux soupapes 6, 7 à tige 8, 9. L'ensemble est porté de façon usuelle par une culasse 10 d'un moteur à combustion interne, la came 4 étant solidaire d'un arbre à cames 11 parallèle à l'axe 2, et le poussoir 5 coulissant dans un guide perpendiculaire à l'arbre 11. Les deux tiges 8, 9, à peu près orthogonales à l'axe 2, coulissent dans la culasse 10 et chacune des soupapes est susceptible d'obturer l'un de deux conduits 12, 13 d'admission ou d'échappement par mise en appui de leur tête évasée 14, 15 sur un siège 16, 17 par lequel le conduit correspondant débouche dans une chambre de combustion 18.We see in the figures a rocker arm 1 which is mounted oscillating on an axis 2 carried by two bearings 3, 3a and which cooperates on one side with a cam 4 via a pusher 5 and on the other side with two valves 6, 7 with stem 8, 9. The assembly is carried in the usual way by a cylinder head 10 of an internal combustion engine, the cam 4 being integral with a camshaft 11 parallel to the axis 2, and the pusher 5 sliding in a guide perpendicular to the shaft 11. The two rods 8, 9, roughly orthogonal to the axis 2, slide in the cylinder head 10 and each of the valves is capable of closing one of two intake or exhaust ducts 12, 13 by pressing their flared head 14, 15 on a seat 16, 17 by which the corresponding duct opens into a combustion chamber 18.

De manière classique, des ressorts (non représentés) exercent respectivement sur chacune des soupapes une poussée axiale permanente tendant à les placer dans leur position de fermeture, position qu'elles atteignent quand le poussoir 5 coopère avec une portion circulaire 4a de la came, tandis qu'elles s'éloignent de leurs sièges en ouvrant les conduits associés 12, 13 quand le poussoir 5 coopère avec un lobe 4b de la came.Conventionally, springs (not shown) exert respectively on each of the valves a permanent axial thrust tending to place them in their closed position, position which they reach when the pusher 5 cooperates with a circular portion 4a of the cam, while that they move away from their seats by opening the associated conduits 12, 13 when the pusher 5 cooperates with a lobe 4b of the cam.

Le culbuteur 1 est monté coulissant sur l'arbre 2 et un espace notable E1, E2 le sépare de chaque palier 3, 3a en direction axiale. Il comporte du côte opposé à la came 4 deux bras 19, 20 à l'extrémité de chacun desquels est formé un bossage 21,22 (figure 3) ou 23, 24 (figure 4) coopérant avec la face extrême 25a, 26a de chacune des tiges (figure 4) ou avec une face 27a, 28a d'un embout 27, 28 rapporté sur l'extremité 25, 26 de la tige correspondante (figure 3).The rocker arm 1 is slidably mounted on the shaft 2 and a substantial space E1, E2 separates it from each bearing 3, 3a in the axial direction. It has on the side opposite to the cam 4 two arms 19, 20 at the end of each of which is formed a boss 21, 22 (FIG. 3) or 23, 24 (FIG. 4) cooperating with the end face 25a, 26a of each. rods (Figure 4) or with a face 27a, 28a of a tip 27, 28 attached to the end 25, 26 of the corresponding rod (Figure 3).

Selon le mode de réalisation de la figure 3, où les soupapes 6 et 7 sont légèrement inclinées symétriquement par rapport à un plan PP perpendiculaire à l'axe 2, les faces 27a, 28a des embouts sont plates et perpendiculaires chacune à l'axe de la tige correspondante, et les faces correspondantes respectives des deux bossages sont bombées par exemple en forme de calotte sphérique.According to the embodiment of Figure 3, where the valves 6 and 7 are slightly inclined symmetrically with respect to a plane PP perpendicular to the axis 2, the faces 27a, 28a of the end pieces are flat and perpendicular each to the axis of the corresponding rod, and the respective corresponding faces of the two bosses are curved, for example in the form of a spherical cap.

Selon le mode de la figure 4, où les tiges 8a, 9a des soupapes sont à peu près parallèles entre elles et orthogonales à l'axe 2, la face extrême 25a, 26a des tiges est bombée en forme de calotte sphérique ou à peu près sphérique, et les bossages 23, 24 coopèrent avec celles-ci respectivement par deux faces planes 23a, 24a symétriquement inclinées par rapport au plan PP précité. Au lieu d'être planes, ces deux faces 23a, 24a peuvent en variante être formées de portions de cylindres ayant leurs génératrices respectives symétriques par rapport au plan PP.According to the mode of FIG. 4, where the stems 8a, 9a of the valves are roughly parallel to each other and orthogonal to the axis 2, the end face 25a, 26a of the stems is curved in the shape of a spherical cap or roughly spherical, and the bosses 23, 24 cooperate with them respectively by two plane faces 23a, 24a symmetrically inclined with respect to the abovementioned plane PP. Instead of being flat, these two faces 23a, 24a can alternatively be formed of cylinder portions having their respective generatrices symmetrical with respect to the plane PP.

Le poussoir 5 comporte un dispositif connu, non représenté ici, de rattrapage de jeu tendant à l'allonger quand il n'est pas soumis à un effort axial notable, en particulier lorsqu'apparaît un jeu de fonctionnement entre le culbuteur et les pièces coopérantes quand les soupapes reposent sur leurs sièges respectifs. En variante, au lieu d'être associé au poussoir 5, le dispositif de rattrapage peut être, de façon connue, interposé entre l'axe 2 et la culasse 10.The pusher 5 comprises a known device, not shown here, for taking up play tending to lengthen it when it is not subjected to a significant axial force, in particular when there appears an operating clearance between the rocker arm and the cooperating parts when the valves rest on their respective seats. As a variant, instead of being associated with the pusher 5, the take-up device can, in known manner, be interposed between the axis 2 and the cylinder head 10.

Grâce à l'inclinaison symétrique des faces 27a, 28a ou 23a, 24a, et grâce au montage coulissant du culbuteur 1 sur son axe 2, le rattrapage de jeu s'effectue pour les deux soupapes à la fois, malgré les imperfections inévitables de fabrication de celles-ci, du culbuteur et des pièces qui les supportent. En effet, si un jeu J de fonctionnement apparaît au droit de l'un 21, 23 des bossages (culbuteur tracé en trait mixte aux figures 3 et 4), la poussée exercée par l'autre bossage 22, 24 sur la face extrême associée 28a, 26 a produit, du fait de l'inclinaison de l'une des deux faces coopérantes par rapport à l'axe 2, un glissement du culbuteur sur cet axe jusqu' à ce que le bossage 21, 23 entre en contact avec la face associée 27a, 25a. Il se produit ainsi un auto- centrage du culbuteur par rapport aux soupapesThanks to the symmetrical inclination of the faces 27a, 28a or 23a, 24a, and thanks to the sliding mounting of the rocker arm 1 on its axis 2, the backlash is effected for the two valves at the same time, despite the inevitable manufacturing imperfections of these, the rocker arm and the parts that support them. Indeed, if an operating clearance J appears at the right of one of the bosses 21, 23 (rocker arm drawn in dashed lines in FIGS. 3 and 4), the thrust exerted by the other boss 22, 24 on the associated end face 28a, 26 produced, due to the inclination of one of the two cooperating faces with respect to the axis 2, a sliding of the rocker arm on this axis until the boss 21, 23 comes into contact with the associated face 27a, 25a. This results in self-centering of the rocker arm with respect to the valves

En variante, le poussoir ne comporte pas de dispositif de rattrapage de jeu mais coopère avec le culbuteur par l'intermédiaire de moyens classiques de réglage de jeu. Ce seul moyen de réglage suffit pour assurer des jeux de fonctionnement égaux pour les deux soupapes puisque si ces deux jeux différaient, le bossage correspondant au plus faible de ces jeux entrerait avant l'autre bossage en contact de la tige associée, provoquant comme indiqué ci-dessus l'autocentrage du culbuteur par glissement sur son axe jusqu'à ce que l'autre bossage atteigne la face coopérante. Cette disposition présente moins d'inertie et est moins onéreuse que celles qui comportent un moyen de réglage au droit de chacun des deux bossages, et elle assure une égalité des deux jeux de fonctionnement même après une éventuelle usure différente des faces coopérantes puisque la correction par auto- centrage du culbuteur s'effectue en permanence pendant le fonctionnement du moteur.As a variant, the pusher does not have a play take-up device but cooperates with the rocker arm by means of conventional clearance adjustment means. This single adjustment means is sufficient to ensure equal operating clearances for the two valves since if these two games differed, the boss corresponding to the weakest of these games would come before the other boss in contact with the associated rod, causing as indicated above the self-centering of the rocker arm by sliding on its axis until the another boss reaches the cooperating side. This arrangement has less inertia and is less expensive than those which include a means of adjustment to the right of each of the two bosses, and it ensures equality of the two operating clearances even after possible different wear of the cooperating faces since the correction by The rocker arm is always self-centering while the engine is running.

Claims (5)

1. Device for actuating two valves (6,7) having a rod (8, 9 - 8a, 9a) comprising a rocker (1) which is pivotally mounted on a shaft (2) and comprises on one side an arm cooperating with a cam (4) and on the other side two arms (19, 20) terminating in bosses (21, 22; 23, 24) which respectively bear against the end (25, 26; 25a, 26a) of associated valve rods, characterized in that the rocker (1) is slidably mounted on its shaft (2), the transmission between the rocker and the cam (4) allowing said sliding and, to the right of each boss, one of the two contacting surfaces of the boss or the end of the rod is curved in the shape of a substantially spherical dome, the other surface being planar or cylindrical, the two planar or cylindrical surfaces being inclined and disposed roughly symmetrically relative to a plane (PP) perpendicular to the shaft of the rocker.
2. Device according to claim 1, wherein the valve rods (8, 9) are inclined roughly symmetrically relative to a plane (PP) perpendicular to the shaft (2) of the rocker (1), characterized in that the end faces (27a, 28a) of the rods in contact with the bosses (21, 22) are perpendicular to the axes of the rods and the surface of each boss (21, 22) is curved roughly in the shape of a spherical dome.
3. Device according to claim 1, wherein the rods (8a, 9a) of the valves are roughly parallel to each other and orthogonal to the shaft (2) of the rocker (1), characterized in that the end surface (25a, 26a) of each rod (8a, 9a) is curved roughly in the shape of a spherical dome and the respective surfaces (23a, 24a) of the bosses (23, 24) are planar or cylindrical.
4. Device according to any one of the claims 1 to 3, characterized in that the rods of the valves carry end members (27, 28).
5. Device according to any one of the claims 1 to 4, characterized in that it comprises a single means for automatically adjusting or taking up the operating clearance associated, for example, with a pushrod (5) interposed between the rocker and the cam (4).
EP19850402230 1984-11-19 1985-11-18 Single rocker arrangement for driving two valves Expired EP0185570B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8417615A FR2573478B1 (en) 1984-11-19 1984-11-19 SINGLE ROCKER DEVICE FOR ACTUATING TWO VALVES
FR8417615 1984-11-19

Publications (2)

Publication Number Publication Date
EP0185570A1 EP0185570A1 (en) 1986-06-25
EP0185570B1 true EP0185570B1 (en) 1988-06-08

Family

ID=9309729

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19850402230 Expired EP0185570B1 (en) 1984-11-19 1985-11-18 Single rocker arrangement for driving two valves

Country Status (5)

Country Link
US (1) US4635679A (en)
EP (1) EP0185570B1 (en)
JP (1) JPS61167108A (en)
DE (1) DE3563237D1 (en)
FR (1) FR2573478B1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4212263A1 (en) * 1992-04-11 1993-10-14 Bayerische Motoren Werke Ag Actuating gear for lifting valves in IC engine - has valve lifter shaft, which is longitudinally displaced to couple neighbouring valve lifters via switching elements
DE102006031031A1 (en) * 2006-07-05 2008-01-10 Schaeffler Kg Lever-like cam follower of a valve train of an internal combustion engine

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1693832A (en) * 1922-04-18 1928-12-04 Packard Motor Car Co Internal-combustion engine
US2024334A (en) * 1933-03-17 1935-12-17 Gen Motors Corp Valve mechanism for internal combustion engines
US2610617A (en) * 1948-10-12 1952-09-16 Pielstick Gustav Combustion engine valve operating means
US2963010A (en) * 1958-05-30 1960-12-06 Austin Motor Co Ltd Overhead valve internal combustion engines
FR1390661A (en) * 1964-04-03 1965-02-26 Saurer Ag Adolph Installation for controlling two valves working in parallel
DE1242045B (en) * 1966-08-20 1967-06-08 Daimler Benz Ag Valve control for a piston internal combustion engine
AT274477B (en) * 1966-10-12 1969-09-25 H C Hans Dipl Ing Dr Dr List Valve control for internal combustion engines
FR2129059A5 (en) * 1971-03-12 1972-10-27 Chrysler France
US3967601A (en) * 1974-09-07 1976-07-06 Motoren- Und Turbinen-Union Friedrichshafen Gmbh Valve control
US4561391A (en) * 1985-04-04 1985-12-31 Ford Motor Company Four valve for cylinder engine with single overhead camshaft

Also Published As

Publication number Publication date
EP0185570A1 (en) 1986-06-25
FR2573478B1 (en) 1987-02-06
US4635679A (en) 1987-01-13
FR2573478A1 (en) 1986-05-23
DE3563237D1 (en) 1988-07-14
JPS61167108A (en) 1986-07-28

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