ES2200570T3 - INTERNAL COMBUSTION ENGINE HEAD COOLED BY LIQUID. - Google Patents

Abstract

Cylinder head (1) for liquid-cooled internal combustion engine, comprising intake (6) and exhaust ducts (7) that flow through the walls (3) of the combustion chambers arranged on its lower face through holes ( 4, 5) cooperating with a stem valve and a circuit (10) for the cooling liquid, especially intended to cool the said walls (3) of the combustion chambers, the cooling circuit (10) comprising steps (14) , 15, 16) of water rise that extend essentially parallel and close to the housings (9) provided for the exhaust valve stems, and a collecting gallery (19) that extends transversely in the upper part of the cylinder head, characterized in that the collecting gallery (19) flows into the lateral face of the cylinder head by means of a water outlet hole (20).

Description

Cylinder head of internal combustion engine by liquid

The present invention relates to a cylinder head for internal combustion engine specially designed to equip a vehicle such as a car or motorcycle. The invention is more particularly it refers to a cooling circuit that extends through an engine head.

The cooling by circulation of a liquid, such as water, it is the most commonly used cooling mode used to cool internal combustion engines, in particular, because it allows to evacuate an important flow of calories, even in very enclosed areas such as the butts, and also because the liquid allows, by its mass, to ensure a certain sound insulation of the engine.

A motor liquid cooling circuit It has, therefore, as main functions, refrigerate the parts  hot engine by forced circulation through this last, and yield to the air the calories thus withdrawn to through a liquid / air heat exchanger too called radiator.

The circulation of the liquid inside the engine it is operated from the bottom up, first through a cavity called a water chamber that is located between the crankcase of cylinders around the cylindrical inner diameters and then through the cylinder head in an appropriate circuit that extends around the combustion chambers.

Today, the generality of the cylinder heads that they carry four valves or more per cylinder to improve performance of the engines, present some delicate problems of cooling due to having less space available to arrange the circulation of the cooling liquid around of combustion chambers, (see, for example, the document DE-A-245299).

On the other hand, no known realization ensures satisfactory cooling of the exhaust valves proper as well as their guides and their seats, or these exhaust valves may be subject to thermal stresses high that reduce the durations of their lives.

The objective of the present invention is to propose a cylinder head for internal combustion engine comprising a circuit cooling that is both efficient and simple to perform.

The cylinder head for internal combustion engine liquid cooled, according to the invention, comprises ducts of intake and exhaust that flow through the walls of the combustion chambers arranged on its lower face, in holes that cooperate with stem valves and a circuit for the cooling liquid intended especially for cooling said combustion chamber walls.

According to the invention, the cylinder head for liquid-cooled internal combustion characterized in that the cooling circuit comprises a few steps of water rise that extend parallel to the housings provided for the stems of the exhaust valves.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, the coolant circuit comprises holes water inlet on the underside of the cylinder head, a chamber of water that extends into the periphery of the chamber walls of combustion, a few steps of rising water that extend basically in parallel and in the proximity of the accommodation of the exhaust valve stems, and a collection gallery that extends transversely in the upper part of the stock to flow into the side face of the cylinder head admission by a water outlet hole.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, the water chamber arranged on the periphery of the walls of a corresponding combustion chamber extends basically parallel to the underside of the cylinder head.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, the water chamber arranged on the periphery of the walls of a corresponding combustion chamber is substantially toric

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, the water rise steps leave the water chamber surrounding partially the exhaust holes arranged through the corresponding combustion chamber walls.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, each combustion chamber that cooperates with a spark plug which is housed in a well that crosses the cylinder head vertically, all or part of the corresponding water rises, is extend in the vicinity of said guide well, especially in the bottom of the latter, to cool the environment of the spark plug electrodes.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, each combustion chamber that cooperates with two exhaust valves, the corresponding water rise steps are then in amount of three, which are, a central step that extends between the two housings provided for the passage of the stems of exhaust, and two lateral steps that extend so noticeably curved to one side and another of the sayings accommodation.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, the water rise steps associated with two combustion chambers adjacent flow into the same collection gallery that extends transversely between the two combustion chambers.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, each water chamber cooperates with a degassing step that extends to the opposite side of the water rise steps, leading the said degassing step on the side face of adjacent admission of the cylinder head.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, the two water chambers that extend on the periphery of two adjacent combustion chambers are joined together by the minus a degassing step that leads to the lower part of the side face of the cylinder head admission through an exit hole specific.

According to another characteristic of the cylinder head for engine of internal combustion cooled by liquid object of the invention, water inlet holes of adapted section lead to each water chamber basically in the vertical steps water rise

The objectives, aspects and advantages of the present invention, according to the description given to continuation of an embodiment of the invention, presented to non-limiting example title, when referring to designs attachments, in which:

Figure 1 is a perspective view of a function core for internal combustion engine cylinder head that defines a refrigeration circuit according to the invention;

Figure 2 is a view similar to Figure 1 where the ducts have been schematized around the soul of water intake and exhaust as well as the corresponding valves;

Figure 3 is a partial bottom view of a cylinder head that has been obtained using the soul of figure 1.

According to the figures, they have only represented the necessary elements for the understanding of invention. In addition, to facilitate the reading of the drawings, the equal pieces bear the same references of a figure in the other.

The cylinder head, with reference 1 in figure 3, which has been chosen to illustrate the water circuit according to the invention,  more particularly it refers to an internal combustion engine of four times and ignition triggered. The operating mode of the engine: four or two stroke, ignition triggered or ignited by compression is not in any way limiting the invention. Similarly, the motor can also be of the same type. single cylinder such as inline, V, or even multi-cylinder type flat.

Then, according to the particular mode of realization of the invention, the most particularly studied engine to equip a motorcycle is a four-cylinder in V comprising two noticeably identical stock. Therefore, it has been represented Only one of the two butts.

The cylinder head 1 represented is of the type of liquid and cross flow cooling (or "cross-flow"), that is, that the ducts of intake and exhaust respectively extend to one side and to another of the middle longitudinal plane of the cylinder head. This butt 1 made of aluminum alloy, it is classically obtained by molding The casting procedure selected in the example illustrated, is a gravity or low pressure casting combining some souls of sand and some outer metal molds. The souls of sand define the different steps that cross the cylinder head 1, such as the intake and exhaust ducts, or even the cooling circuit

The cylinder head 1 comprises, on its lower face 2 destined to go supported with interposition of a board against the cylinder housing not shown, walls 3 of shapes adapted that delimit two combustion chambers. These two cameras of combustion flow in front of the inner diameters corresponding cylindrical crankcase cylinders, are identical and extend basically along the longitudinal axis of the stock 1.

The walls 3 that delimit the chambers of combustion are perforated with two intake holes 4 and two exhaust holes 5 provided with additional seats. The holes 4 and 5 extending to one side and another of the middle plane length of the cylinder head, are extended by means of ducts 6 and 7 (represented in dotted lines in Figure 2) respectively of intake of the carbureted mixture and exhaust of the burned gases. These intake and exhaust ducts 6 and 7 they extend through the cylinder head 1 to drain, respectively, on the upper face of the cylinder head and on a side face of the latter also called face of "escape".

Holes 4 and 5 cooperate with valves  slider mounted rod with two additional guides inserted in corresponding housings of the stock. These valves are maneuvered by mechanisms of Appropriate drive not shown. In figure 2 only Accommodations 8 and 9 of the guides of valves, intake and exhaust, respectively, with traces of points.

The cylinder head 1 has, on the other hand, a few steps or wells 13 which extend basically in the axis of the cylinders and basically leading to the center of each of the walls 3 which delimit the combustion chambers to allow the passage of Spark plugs, not shown.

According to the invention, the cylinder head comprises a circuit from cast iron adapted for the circulation of cooling liquid from the crankcase.

Referring to figures 1 and 2, it can be understand more precisely the shape of the circuit cooling from the corresponding sand core.

The cooling circuit is described in the case of a cylinder head with two combustion chambers, but, obviously it can be prolonged or reduced to be used on any stock, regardless of the number of cameras combustion.

The cooling circuit is presented under the form of two basically identical elementary circuits 10 and each adapted for cooling a chamber of given combustion.

Each elementary circuit 10 is composed of a annular cavity 11, also called a water chamber, which extends on the periphery of the walls 3 of the chamber of corresponding combustion, of a few steps of said steps of water rise 14, 15 and 16, which basically extend in parallel and close to the housing of the stems of the exhaust valves and a collection gallery 19 that extends transversely at the top of the cylinder head, to drain on the side face called "admission" of the cylinder head by a water outlet hole 20.

Each water chamber 11 is fed with a cooling liquid through 12 calibrated holes that flow into the lower face of the cylinder head 1, as has been represented in figure 3. These holes, arranged opposite of corresponding holes in the upper crankcase table of cylinder, are adapted to feed the water chamber 11 according to an adapted flow of cooling liquid.

Each water chamber 11 more or less O-ring is arranged on the periphery of the walls 3 of the corresponding combustion chamber, to basically extend parallel to the underside of the cylinder head.

The steps of water rise 14, 15, 16 associated to a water chamber 11, they depart from the latter surrounding the exhaust valve seats positioned collinear with the exhaust holes 9.

These water rise steps are in quantity of three, that is, they are, a central step 15 that extends in parallel and between the two housings 9 of the stems of the exhaust valves, and two lateral passages 14 and 16 that extend basically curved around housings 9 of the exhaust valve stems.

The lateral water rises 14 and 15, which extend, on the other hand, near the well 13 of the spark plug, especially at the bottom of the latter, to refrigerate the surroundings of the spark plug electrodes.

The two elementary circuits 10 associated with two adjacent combustion chambers together lead to a same collecting gallery 19 that extends transversely between The two combustion chambers.

On the other hand, the two circuits 10 put in communication the water chambers 11 by two steps, a step 18 that extends basically on the longitudinal axis of cylinder head 1, and a step 17 which serves more particularly to degas the circuits, which runs opposite steps 14, 15, 16 up of water to drain onto the adjacent side intake side  of the cylinder head through a hole 21 other than hole 20.

To favor the circulation of the liquid of cooling in the water rise steps 14, 15, 16 and, by both, obtain efficient cooling of the guides and exhaust valves, an inlet port 12 of adapted section water, basically in the vertical of each of The steps of water rise.

Claims (11)

1. Cylinder head (1) for liquid-cooled internal combustion engine, comprising intake (6) and exhaust ducts (7) that flow through the walls (3) of the combustion chambers arranged on its lower face by holes (4, 5) cooperating with a stem valve and a circuit (10) for the cooling liquid, especially intended to cool the said walls (3) of the combustion chambers, the cooling circuit (10) comprising steps (14, 15, 16) of rising water that extend essentially parallel and near the housings (9) provided for the exhaust valve stems, and a collecting gallery (19) that extends transversely in the upper part of the cylinder head, characterized in that the collecting gallery (19) flows into the lateral face of the cylinder head by means of a water outlet hole (20). 2. Cylinder head (1) for a liquid-cooled internal combustion engine according to claim 1, characterized in that, for each combustion chamber, the cooling liquid circuit (10) comprises water inlet holes (12) that flow into the lower face (2) of the cylinder head, a water chamber (11) that extends on the periphery of the walls (3) of the combustion chamber, water rises (14, 15, 16) extending in essence in parallel and close to the housings (9) of the exhaust valve stems. 3. Cylinder head (1) for liquid-cooled internal combustion engine according to claim 2, characterized in that the water chamber (11) disposed on the periphery of the walls (3) of a corresponding combustion chamber essentially extends parallel to the underside (2) of the cylinder head (1). 4. Cylinder head (1) for liquid-cooled internal combustion engine according to claim 3, characterized in that the water chamber (11) disposed on the periphery of the walls (3) of a corresponding combustion chamber, is basically theoretical . 5. Cylinder head (1) for liquid-cooled internal combustion engine according to any one of claims 2 to 4, characterized in that the water rises (14, 15, 16) exit from the water chamber (11) partially surrounding the exhaust holes (5) arranged through the walls (3) of the corresponding combustion chamber. 6. Cylinder head (1) for liquid-cooled internal combustion engine according to any one of claims 2 to 5, characterized in that in each combustion chamber cooperating with a spark plug that is housed in a well (13) that crosses vertically the cylinder head (1), all or part of the corresponding water rises (14, 16) extend near said spark plug well (13), especially in the lower part of the latter, to cool the area near the spark plug electrodes. 7. Cylinder head (1) for liquid-cooled internal combustion engine according to any one of claims 2 to 6, characterized in that, by cooperating each combustion chamber with two exhaust valves, the corresponding water rises are then in number of three, namely, a central passage (15) that extends between the two housings (9) provided for the passage of the exhaust rods, and two lateral passages (14, 16) that extend in a basically curved way to one side and to another of these accommodations (9). 8. Cylinder head (1) for liquid-cooled internal combustion engine according to any one of claims 2 to 7, characterized in that the steps (14, 15, 16) of water rise associated with two adjacent combustion chambers, flow into a same collection gallery that extends transversely between the two combustion chambers. 9. Cylinder head (1) for liquid-cooled internal combustion engine according to any one of claims 2 to 8, characterized in that each water chamber (11) cooperates with a degassing passage (17) extending opposite the steps ( 14, 15, 16) of water rise, said degassing passage (17) flowing into the adjacent side admission face of the cylinder head (1). 10. Cylinder head (1) for a liquid-cooled internal combustion engine according to claims 8 and 9, characterized in that the two water chambers (11) extending on the periphery of two adjacent combustion chambers are joined together by the less a degassing step (17) that flows into the lower part of the side face of the cylinder head (1) through a specific outlet (21). 11. Cylinder head (1) for liquid-cooled internal combustion engine according to any one of claims 2 to 10, characterized in that water inlet holes (12) basically in the vertical of the steps (14, 15, 16) water rise.