EP2881316A1 - Heat engine and vehicle provided with such an engine - Google Patents

Abstract

The invention relates to a heat engine, of the type comprising a camshaft (12), a cylinder provided with a cylinder head (1), at least one valve (4, 5) movable through an opening of the cylinder head and controlled by the rotation of the camshaft via a linkage (14, 16, 22), and elastic return means (9) of the valve to a closed position in which the valve head (5) is applied on a seat (7) of the cylinder head, characterized in that it comprises: - a support (24) integral with the cylinder head (1); - a pusher (26) movable relative to the support between a rest position, in which the pusher is moved away from the linkage (14, 16, 22) when the valve (4, 5) is in its closed position, and an active position in which the pusher pushes the valve a predetermined distance against said biasing means (9) causing the valve head (5) to be raised relative to the seat (7); and - Slow turning means (28 to 30, 13) for driving at least a very slow speed the engine (102) over at least one complete revolution. Application to propulsion diesel engines of submarines.

Description

The present invention relates to a heat engine of the type comprising a camshaft, a cylinder provided with a cylinder head, at least one valve movable through an opening of the cylinder head and controlled by the rotation of the camshaft via a linkage, and elastic return means of the valve to a closed position in which the valve head is applied to a seat of the cylinder head.

The invention is particularly applicable to diesel engines used for propulsion or power generation aboard submarines, and will be described later in this application.

When a thermal engine submarine is diving at shallow depth (using the Schnorchel) with its engine off, there is a risk of seawater entering the engine cylinders.

Such a water intrusion presents a significant risk if the engine is started, because the compression of a body of water can damage certain essential parts of the engine.

Some manufacturers have, for this reason, proposed to add to each cylinder an additional valve dedicated to the evacuation of water. When water is detected in a cylinder, this additional valve is opened, and the engine is driven into a "slow turn" at a sufficient angle of rotation to ensure the expulsion of the water, before the engine is started. This angle of rotation is at least one turn.

This solution is expensive, however, because it uses a specific engine.

The invention aims to provide an economically adaptable solution to any existing heat engine.

• un support solidaire de la culasse ;
• un poussoir mobile par rapport à ce support entre une position de repos, dans laquelle le poussoir est éloigné de la tringlerie lorsque la soupape se trouve dans sa position de fermeture, et une position active dans laquelle le poussoir repousse la soupape sur une distance prédéterminée à l'encontre desdits moyens de rappel en provoquant le soulèvement de la tête de la soupape par rapport au siège ; et
• des moyens de virage lent pour entrainer à au moins une vitesse très lente le moteur thermique sur au moins un tour complet.

For this purpose, the subject of the invention is a heat engine of the aforementioned type, characterized in that it comprises:

• a support integral with the breech;
• a pusher movable relative to the support between a rest position, wherein the pusher is moved away from the linkage when the valve is in its closed position, and an active position in which the pusher pushes the valve a predetermined distance to against said biasing means by causing the head of the valve to raise relative to the seat; and
• slow turning means for driving at least a very slow speed the engine over at least one complete revolution.

• le poussoir en position active, coopère avec un organe de réglage du jeu de la soupape, cet organe de réglage étant prévu sur la tringlerie ;
• le poussoir est une tige filetée vissée dans un écrou fixé dans une ouverture dudit support, la tige filetée étant munie d'une tête d'entrainement en rotation située à l'extérieur du support ;
• les moyens de virage lent sont adaptés pour entrainer le moteur thermique sur au moins un tour complet à l'une ou l'autre de deux vitesses très lentes ;
• les moyens de virage lent comprennent des moyens d'entrainement manuel en rotation du moteur thermique ;
• les moyens de virage lent comprennent un moteur électrique ou pneumatique d'entrainement en rotation du moteur thermique ;
• un moteur thermique tel que décrit ci-dessus, en ce qu'il comprend des moyens de mesure d'une grandeur représentative de la présence d'eau dans le cylindre pendant une première opération de virage lent du moteur thermique ;
• lesdits moyens de mesure sont adaptés pour déclencher une seconde opération du virage lent du moteur thermique ;
• le moteur thermique est un moteur diesel.

According to other features of the invention:

• the pusher in the active position cooperates with a valve play adjustment member, this adjusting member being provided on the linkage;
• the pusher is a threaded rod screwed into a nut fixed in an opening of said support, the threaded rod being provided with a rotating drive head located outside the support;
• the slow turning means are adapted to drive the engine over at least one complete revolution at one or the other of two very slow speeds;
• the slow turning means comprise means for manually rotating the heat engine;
• the slow turning means comprise an electric or pneumatic motor for rotating the heat engine;
• a heat engine as described above, in that it comprises means for measuring a magnitude representative of the presence of water in the cylinder during a first slow turning operation of the heat engine;
• said measuring means are adapted to trigger a second operation of the slow turning of the heat engine;
• the engine is a diesel engine.

The invention also relates to a vehicle, in particular a submarine, equipped with at least one heat engine as defined above.

• la figure 1 représente schématiquement, en coupe, une partie d'un moteur thermique classique auquel s'applique l'invention ;
• la figure 2 est une vue analogue du moteur de la figure 1, modifié conformément à l'invention ; et
• la figure 3 est une vue analogue qui illustre le fonctionnement du moteur de la figure 2.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

• the figure 1 schematically represents, in section, a part of a conventional thermal engine to which the invention applies;
• the figure 2 is a similar view of the engine of the figure 1 modified according to the invention; and
• the figure 3 is a similar view that illustrates the operation of the engine of the figure 2 .

We have shown on the figure 1 a part of the cylinder head 1 of a diesel engine 2 for the propulsion of a submarine. The engine comprises several cylinders in each of which moves a piston 3.

In the cylinder head 1 slide several valve rods for each cylinder, including the two rods 4 of the two cylinder exhaust valves. We also see on the figure 1 the exhaust manifold 6 of the cylinder head, which opens on two exhaust ports. Around each exhaust port is defined a seat 7 for the head 5 of the associated exhaust valve. In the drawings, the rods 4 are shown vertical, as well as the axis XX of the cylinder.

Each rod 4 carries at its upper end, outside the cylinder head, a plate or cup 8. A helical return spring 9 is compressed between this plate and the upper face 10 of the cylinder head, in order to return the valve to a valve. closing position in which the head 5 is applied on its seat 7.

• le vilebrequin 11 du moteur, lequel entraîne de façon synchronisée l'arbre à cames 12 et le piston 3 ;
• le démarreur électrique (ou, en variante, pneumatique) 13 du moteur, adapté pour entrainer en rotation le vilebrequin ;
• une tige de culbuteur 14 dont l'extrémité inférieure est en appui sur la came associée 15 de l'arbre à cames ;
• un basculeur 16 monté oscillant sur un arbre 17 solidaire de la culasse. Un bras 18 du basculeur est au contact de l'extrémité supérieure de la tige 14, tandis que son autre bras 19 comporte un perçage taraudé 20 dans lequel est vissée une vis de réglage 21 ; et
• un pontet 22 dont les extrémités sont en appui sur les extrémités supérieures des tiges de soupape 4, respectivement, et dont la région médiane porte un bossage supérieur 23 maintenu au contact de la vis 21 par les ressorts de rappel 9.

We have again very schematically represented on the figure 1 :

• the crankshaft 11 of the engine, which synchronously drives the camshaft 12 and the piston 3;
• the electric starter (or, alternatively, pneumatic) 13 of the engine, adapted to drive in rotation the crankshaft;
• a rocker rod 14 whose lower end bears on the associated cam 15 of the camshaft;
• a rocker 16 mounted oscillating on a shaft 17 integral with the cylinder head. An arm 18 of the rocker is in contact with the upper end of the rod 14, while its other arm 19 has a threaded hole 20 in which is screwed a set screw 21; and
• a bridge 22 whose ends are supported on the upper ends of the valve rods 4, respectively, and whose middle region carries an upper boss 23 held in contact with the screw 21 by the return springs 9.

The figure 2 schematically shows how the engine 2 is modified to solve the problem of possible water ingestion by one or more cylinders, in this case the cylinder shown. The modified engine has the reference 102.

The engine 102 has a cylinder head cover 24 secured to the cylinder head and traversed by a threaded sleeve 25 integral with the cylinder head cover. In this sleeve is screwed a needle screw 26 whose lower end, inside the cylinder head cover, is opposite the upper head of the adjusting screw 21. The upper end of the screw-needle 26, external to the cylinder head cover, carries a rotational drive head, in this example a radial rod 27 manually operated.

The motor 102 is completed by a sensor 28 of the speed of rotation of the camshaft according to its angular phase, and by a device 29 for driving the starter 13 in "slow bend" mode, that is to say -Training of the crankshaft at a very slow speed. A very slow speed is understood to mean a speed of rotation which is much lower than the minimum operating speed of the motor 102, for example between 0.5 and 5 revolutions per minute. In the example described here, the device 29 is adapted to drive the crankshaft to one or the other of two slow speeds, the first of the order of 1 turn per second. minute for the detection of water, the second of the order of 5 revolutions per minute for the evacuation of water from the cylinder, as will be described later.

The device 29 can be controlled independently of the sensor 28, for example manually as shown schematically by an actuating button 30.

The motor 102 operates as follows.

In normal operating condition, the needle screw 26 is unscrewed so as to be spaced from the adjusting screw 21 whatever the position of the rocker 16 ( figure 2 ). The sensor 28 and the control device 29 are deactivated.

1. (a) On active le capteur 28,
2. (b) Au moyen du bouton 30, on actionne manuellement le dispositif 29, lequel provoque le fonctionnement du démarreur 13 en mode « virage lent » sur au moins un tour du vilebrequin, à la première vitesse lente précitée.
3. (c) Pendant ce virage lent, le capteur 28 mesure la vitesse de rotation de l'arbre à cames (ou en variante, du vilebrequin) en fonction de la phase angulaire de celui-ci, et compare cette vitesse de rotation à une valeur normale.
4. (d) Si, pour une phase donnée, correspondant à une position du piston 3 voisine de son point mort haut, la vitesse de rotation diminue substantiellement par rapport à la valeur normale, ceci est l'indice d'un « point dur » qui peut être dû à la présence d'eau dans le cylindre, au-dessus du piston, cette eau ayant pénétré par le collecteur d'échappement 6.
5. (e) Le capteur 28 déclenche alors une alarme, et l'opérateur effectue les deux opérations suivantes, illustrées sur la figure 3.
6. (f) Il fait tourner le levier 27 sur un angle prédéterminé (flèche F de la figure 3). Ceci amène l'extrémité inférieure de la vis 26 au contact de la tête de la vis 21, puis repousse celle-ci vers le bas. Cet effort se transmet au bossage 23 du pontet 22, lequel repousse vers le bas les deux soupapes d'échappement. Les têtes 5 des deux soupapes se décollent ainsi de leurs sièges 7, avec un écartement suffisamment faible pour ne pas interférer avec le piston 3 lorsque celui-ci se trouve à son point mort haut (jeu i de la figure 3).
7. (g) Puis l'opérateur, au moyen du bouton 30, actionne le dispositif 29, lequel, provoque le fonctionnement du démarreur 13 en mode « virage lent » sur au moins un tour du vilebrequin, à la seconde vitesse lente précitée.

When there is a condition where the risk of ingestion of water in the cylinder can occur, for example after a dive of the submarine shallow with its engine 102 stopped, the following steps are carried out:

1. (a) Activate the sensor 28,
2. (b) By means of the button 30, the device 29 is manually actuated, which causes the starter 13 to operate in "slow turn" mode on at least one revolution of the crankshaft, at the first aforementioned slow speed.
3. (c) During this slow turn, the sensor 28 measures the rotational speed of the camshaft (or alternatively, the crankshaft) according to the angular phase thereof, and compares this rotation speed with a value normal.
4. (d) If, for a given phase, corresponding to a position of the piston 3 close to its top dead center, the speed of rotation decreases substantially with respect to the normal value, this is the index of a "hard point" which may be due to the presence of water in the cylinder, above the piston, this water having entered through the exhaust manifold 6.
5. (e) The sensor 28 then triggers an alarm, and the operator performs the following two operations, illustrated on the figure 3 .
6. (f) It turns the lever 27 to a predetermined angle (arrow F of the figure 3 ). This brings the lower end of the screw 26 into contact with the head of the screw 21, then pushes the latter downwards. This force is transmitted to the boss 23 of the bridge 22, which pushes down the two exhaust valves. The heads 5 of the two valves are thus detached from their seats 7, with a spacing sufficiently small not to interfere with the piston 3 when it is at its top dead center (clearance i of the figure 3 ).
7. (g) Then the operator, by means of the button 30, actuates the device 29, which causes the operation of the starter 13 in "slow turn" mode on at least one revolution of the crankshaft, at the second slow speed mentioned above.

At the end of this slow turn, it is ensured that enough water has been driven from the cylinder, via the exhaust manifold 6 (arrows f of the figure 3 ) so that, subsequently, no volume of water is compressed by the rise of the piston.

1. (1) Le moteur 102 peut être équipé d'un moteur électrique ou pneumatique spécifique, différent du démarreur 13, pour provoquer le virage lent expliqué ci-dessus.
2. (2) Le dispositif 29 peut être commandé par le capteur 28 pour déclencher automatiquement le virage lent lorsqu'un « point dur » est détecté. Il peut également être actionné par un automate programmé.
3. (3) Le virage lent peut être réalisé de façon manuelle, grâce par exemple à un système à clé à cliquet prévu sur le moteur 102, schématisé en 31 sur la figure 3.
4. (4) Le système 24 à 27 d'ouverture forcée des soupapes peut être disposé sur au moins une soupape quelconque existante du moteur thermique 102, par exemple sur une ou deux soupapes d'admission.
5. (5) La détection de la présence d'eau dans le cylindre peut s'effectuer de façon manuelle en constatant la présence d'eau sur la purge du collecteur d'échappement.
6. (6) Le poussoir manuel 25 à 27 peut être remplacé par un vérin automatisé commandé par un actionneur électrique.

Several variants can be envisaged:

1. (1) The motor 102 may be equipped with a specific electric or pneumatic motor, different from the starter 13, to cause the slow turn explained above.
2. (2) The device 29 may be controlled by the sensor 28 to automatically trigger the slow turn when a "hard point" is detected. It can also be operated by a PLC.
3. (3) The slow turn can be achieved manually, for example by means of a ratchet system provided on the engine 102, diagrammed at 31 on the figure 3 .
4. (4) The system 24 to 27 forced opening of the valves may be disposed on at least one existing valve of the engine 102, for example on one or two intake valves.
5. (5) The detection of the presence of water in the cylinder can be done manually by noting the presence of water on the purge of the exhaust manifold.
6. (6) The manual pusher 25 to 27 can be replaced by an automated cylinder controlled by an electric actuator.

Claims (9)

A thermal engine, of the type comprising a camshaft (12), a cylinder provided with a cylinder head (1), at least one valve (4, 5) movable through an opening of the cylinder head and controlled by the rotation of the cylinder camshaft via a linkage (14, 16, 22), and resilient return means (9) of the valve to a closed position in which the valve head (5) is applied to a seat (7) of the breech, characterized in that it comprises: - a support (24) integral with the cylinder head (1); - a pusher (26) movable relative to the support between a rest position, in which the pusher is moved away from the linkage (14, 16, 22) when the valve (4, 5) is in its closed position, and an active position in which the pusher pushes the valve a predetermined distance against said biasing means (9) causing the valve head (5) to raise relative to the seat (7); and - Slow turning means (28 to 30, 13) for driving at least a very slow speed the engine (102) over at least one complete revolution; - Means (28) for measuring a magnitude representative of the presence of water in the cylinder during a first slow turning operation of the engine (102). Thermal engine according to claim 1, characterized in that the pusher (26), in the active position, cooperates with a member (21) for adjusting the clearance of the valve (4, 5), this adjustment member being provided on the linkage (14, 16, 22). Heat engine according to claim 1 or 2, characterized in that the pusher (26) is a threaded rod screwed into a nut (25) fixed in an opening of said support (24), the threaded rod (26) being provided with a head (27) rotational drive located outside the support (24). Thermal engine according to Claim 3, characterized in that the slow turning means (28 to 30, 13) are adapted to drive the heat engine (102) over at least one complete revolution at one or the other of two speeds. very slow. Thermal engine according to any one of the preceding claims, characterized in that the slow turning means comprise means (31) for manually rotating the heat engine (102). Thermal engine according to any one of the preceding claims, characterized in that the slow turning means comprise an electric or pneumatic motor (13) for rotating the heat engine (102). Thermal engine according to any one of the preceding claims, characterized in that the measuring means (28) of a magnitude representative of the presence of water in the cylinder are adapted to trigger a second operation of the slow turning of the heat engine ( 102). Thermal engine according to any one of the preceding claims, characterized in that the heat engine (102) is a diesel engine. Vehicle, in particular a submarine, characterized in that it comprises at least one heat engine (102) according to any one of the preceding claims.

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