FR2915233A1 - Autonomous lubricating system for motor vehicle, has lubricant circuit between top and bottom point of cylinder head, and channeling system above cam shaft for realizing lubrication of mechanical parts of cylinder head with descending flow - Google Patents

Abstract

The system has a lubricant circuit extending between a top point (12) and a bottom point (11) of a cylinder head. The top point supplies a channeling system with lubricant for realizing lubrication. Guiding units (42) guide the oil in ascending manner from an inlet zone (E), and a movable part in a shape of a toothed wheel (4) is driven in rotation by driving units to bring the oil on the periphery of the wheel and along the units (42). A channeling system is placed above a cam shaft and realizes lubrication to mechanical parts of the cylinder head with descending flow.

Description

Autonomous lubrication system for mechanical parts of a cylinder head

  TECHNICAL FIELD OF THE INVENTION The present invention relates to the mechanism of lubricating mechanisms in thermal engines, especially motor vehicles. The invention more particularly relates to an autonomous lubrication system for mechanical members of an engine cylinder head and a cylinder head having an autonomous lubrication. The invention also relates to a use of a toothed or paddle wheel in a cylinder head to engine. BACKGROUND OF THE INVENTION It is known to use pressurized oil from the crankcase lubrication circuit to lubricate metal members of a cylinder head of an engine. A disadvantage of this type of lubrication is the need for the oil pump to be climed together, with more oil to be shipped for the purpose of the cylinder head. In addition, the oil is charged with carbonaceous material in contact with the combustion gases that pass through the segmentation, and thus becomes less efficient for the contacts of the distribution in the cylinder head. This oil ages and all oil must be replaced at each oil change. This type of solution is therefore expensive without achieving the best lubrication performance. It is also known, from document FR 2 775 020, to integrate in the cylinder head an oil reservoir independent of the cylinder block, permitting lubrication of the internal elements of the cylinder head by bubbling. The oil reserve, located in the bottom of the cylinder head, however does not allow to properly distribute the lubrication as desired. This solution requires more oil (and therefore a greater volume of oil to be replaced during emptying) and does not allow selective lubrication of the elements of the distribution.

  GENERAL DESCRIPTION OF THE INVENTION The present invention aims to overcome one or more disadvantages of the prior art by proposing a cylinder head lubrication system which is self-contained and makes it possible to effectively lubricate internal elements of the cylinder head (bearings of the cylinder head). camshaft and valve shanks and distributor rollers). This object is achieved by an autonomous lubrication system for mechanical members of an engine cylinder head, characterized in that it comprises a lubricant circuit (also called an oil circuit) extending between a high point and a low point of the cylinder head, the high point lubricating a piping system for carrying out the lubrication, and transport means for circulating the lubricant from said low point to the high point of the circuit, the piping system feeding the lubricant to at least one point in height above the organs to be lubricated. Thus, autonomous lubrication can be achieved with gravity oil flow, specifically in the areas to be lubricated. The high point can be used to feed a downstream network of pipes to distribute oil directly to the heating zones. This is a lubrication of the cylinder head which is completely independent of that provided for the crankcase. Since the volume of oil required for the cylinder head does not need to be pressurized, no pumping is required at the cylinder head. This allows a sizing of the smaller oil pump (just needed for the low engine). In addition, since the oil of the cylinder head is not in contact with the combustion gases, it ~ s can be kept longer or even life according to its initial qualities. In what follows, the lubricant is called oil, these two terms being interchangeable as may be appreciated by those skilled in the art. According to another particularity, the means of transport comprise: guiding means for guiding oil upwardly from an oil arrival zone located at the low point; and a movable part generally having a gear shape and driven in rotation by drive means for conveying the oil on its periphery and along the guide means to oil receiving means flush with the moving part and constituting said the high point. According to another feature, the movable part is a toothed or paddle wheel, driven in rotation via a camshaft introduced into the cylinder head. According to another feature, the circuit comprises an oil collector including a slope channel formed in the cylinder head, this channel opening on an upstream side below the camshaft and a downstream side in the space where is housed the wheel. In another feature, the oil receiving means comprises an upstream end of a chute contiguous to a surface of a cover of the cylinder head (ceiling surface). According to another feature, the chute extends along a longitudinal axis of the cylinder head and feeds via branches a plurality of local lubrication zones. In another feature, the chute distributes oil in channels of different section and / or inclination conveying the oil, the oil flow being adjusted by a sizing of the section and the inclination of each In another feature, the pipeline system for performing the lubrication is down-flow and is located above the bearings of a camshaft and valve shanks and distributor rolls. According to another feature, the oil circuit is devoid of oil pump and at least the pipe system comprises sloped pipes to facilitate a flow of the oil. Thus, the system plans to route the oil to a high point of the cylinder head, the oil can then flow in pipes with a slight slope and thus be distributed in the lubrication zones.

  According to another feature, the system comprises an oil reserve volume communicating with the oil circuit at said low point. In another feature, the oil circuit splits in two in the cylinder head as follows: a downstream circuit portion; and an oil climbing compartment enclosing the means of transport. A further object of the present invention is to provide an engine cylinder head to reduce the volume of oil required for the lubrication of the mechanical members of the cylinder head, and to minimize the displacement of the engine associated oil pump. For this purpose, the invention relates to a cylinder head having an autonomous lubrication, characterized in that it comprises an oil circuit 15 which is divided in two in the cylinder head as follows: a descending circuit part; and an oil climbing compartment, enclosing transport means including a wheel rotated. Thus, the yoke according to the invention is advantageously lubricated autonomously and efficiently with a minimum volume of oil. According to another feature, the downward circuit portion comprises a pipe system mounted or integrated on the underside of a cover of the cylinder head to route and drop oil on mechanical members in the cylinder head. According to another feature, the cylinder head includes a system according to the invention. A further object of the present invention is to provide a use of oil conveying means in an engine cylinder head, enabling the realization of an independent lubrication circuit with a lubricant circulation. For this purpose, the invention relates to a use of a conveyor wheel in an engine cylinder head, characterized in that the rotational drive of the wheel serves in an oil circuit to mount oil from a point bottom of the circuit to a high point of the circuit, whereby the oil can flow from said high point by gravity to lubrication areas of mechanical organs present in the cylinder head.

  According to another particularity, the conveyor wheel is of toothed or paddle wheel type, placed at one end of a camshaft. Other features and advantages of the present invention will appear more clearly on reading the description below, made with reference to the accompanying drawings, in which: FIG. 1 represents an end compartment of a cylinder head; motor according to the invention, including an oil conveyor wheel; Figure 2 shows a side view of the lower portion of the compartment of Figure 1 to illustrate the flow of oil to the low point of the lubrication circuit; Figure 3 is a top view of the cylinder head of Figure 1 along the section plane B-B, illustrating the distribution of oil via a pipe system; Figure 4 is a view along the sectional plane C-C of the cylinder head of Figure 1, illustrating the return of oil to the compartment housing the conveyor wheel; - Figure 5 is a sectional view parallel to the view of Figure 1, illustrating the distribution of oil dropwise on elements that need to be lubricated in the cylinder head. DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION The system according to the invention allows autonomous lubrication of mechanical members of a motor cylinder head (1) with a reduced lubricant volume. With reference to FIG. 3, the system comprises in the cylinder head (1) a lubrication circuit provided with a device for raising oil (lubricant) and a pipe system (5) discharging from the high point of the circuit the oil to the lubrication areas. Thus, the cylinder head can be lubricated at the necessary points. This oil then descends into at least one manifold which brings the oil to a lower level of the lift device.

  In the preferred embodiment of the invention, a wheel (4) conveyor, for example toothed or paddle, is rotated to raise the oil. In known manner, the startup of the motor is accompanied by a rotation of the camshaft (3). The system provides for example that the camshaft rotates, directly or indirectly, the wheel (4) which, by the centrifugal effect, sends the oil into a receiving zone (50) of a chute ( BOY WUT). This chute (G) may be slightly inclined to promote the circulation of the oil. The chute (G) channels the oil that feeds, drip, the various elements that need to be lubricated in the cylinder head (1). Referring to Figure 3, the longitudinal chute (G) constitutes an inlet manifold of the pipeline system (5). The latter makes it possible to distribute the flow specifically in the areas to be lubricated. In the example of FIGS. 2 and 4, the oil can advantageously be redirected towards the wheel (4) by means of at least one slope in the cylinder head (1) to land, through an opening in the cylinder head ( 1) in an arrival zone (E) at the bottom of the conveyor wheel (4). The cylinder head (1) is provided with a specific lubricant that ages less rapidly because the closed circuit is independent of the cylinder block. The oil circuit is disposed between a high point (12) and a low point (11), as illustrated in FIG. 1. The high point (12) is the receiving zone (50) of the distributor chute and the low point (11) is located in the oil arrival zone (E) at the bottom of the ascent device. It is during the descent journey that lubrication takes place. The circuit is thus divided into two parts: the downstream circuit part, including the pipe system (5) for carrying out the lubrication; and - the compartment (30) of ascension where is housed the device of ascent.

  The recovery device provides a circuit without pump and independent. This circuit generally forms a loop which is enclosed within the yoke (the compartment (30) being preferably disposed at one end of the yoke (1) as illustrated in FIG. 3). Referring to FIG. 1, the raising device comprises guiding means (42) for guiding the oil upwardly from the arrival zone (E) and a moving part generally having a toothed wheel shape ( 4). This moving part is rotated by drive means to route the oil on the periphery of the wheel (4) ~ o and along the guide means (42). The oil thus rises along a curved wall of the guide means (42) to be projected by the conveyor wheel (4) to the receiving zone (50) flush with the movable portion (4). This receiving zone (50) can be formed at the upstream (in this case the highest) end of the chute (G). In the example of Figures 1 and 5 5, the chute (G) is contiguous to a surface forrnant ceiling, a cover of the cylinder head (1) With reference to Figure 3, the chute (G) extends along a longitudinal axis of the yoke (1) and feeds via branches a plurality of local lubrication areas. The piping system (5) can be mounted or integrated on the underside of the cylinder head cover. The pipeline system (5) for lubricating is preferably down-flow and is located above the camshaft (3). The free ends of the channels and orifices of this system (5) make it possible to drop oil precisely on certain mechanical components present in the cylinder head (1), in zones to be lubricated. In one embodiment of the invention, the chute (G) dispenses oil in channels of different section and / or inclination and the oil flow is thus adjusted by a dimension of the section and the inclination of each channel. More generally, each oil path can be calibrated as needed to regulate flow. Lubrication is carried out from above, on the mechanical parts to be lubricated in the cylinder head (1).

  Once the oil is poured on these mechanical members, it flows towards the bottom of the housing for the camshaft (3), for example at the base of a bearing (32) of the camshaft (3). ). At this location, as shown in Figure 4, the circuit may include an oil manifold including a sloping channel (ch) formed in the cylinder head (1) to allow a return of the oil to the lift device. This channel (ch) opens on an upstream side below the camshaft (3) and a downstream side in the space where the wheel (4) is housed. With reference to FIG. 2, the channel (ch) has its downstream end adjacent to the wheel. The low point (11) can be supplied with oil on the one hand via a first oil inlet communicating with the sloped channel (ch), and secondly via a second oil inlet communicating with a reservoir of oil. oil (2). The second arrival may correspond to a horizontal pipe, formed by a bore (20) in a wall of the tank (2). The first arrival is by lowering the oil via an inlet opposite to the bore (20). In the example of Figures 1 and 3, the conveyor wheel (4) is gear type (gear type) or paddle and is placed at one end of the camshaft (3). The guide means (42) form an inclined half-circle oriented towards the receiving zone (50) of the chute (G). An entry space in the wheel, at the low point (11) separates the guide means (42) of a circular wall which allows to reduce the residual quantities of oil having made a complete turn at this space input. The chute (G) descends to the edge of the teeth or 25 vanes (41) of the wheel (4) and is open laterally to collect a maximum of oil sprayed under the effect of centrifugal force by the wheel (4) . The semicircle of the guide means (42) stops before the chute (G), so as to let the oil escape on an angular sector of the order of 40-80 at the top of the lift device. This angular sector is 3a bounded on one side by the bottom of the chute (G) and on the other side by the upper end of the semicircle of the guide means (42). A ceiling formed for example by the cover of the cylinder head supplements the semicircle for guiding the oil to the receiving zone (50) of the chute (G). Other known dating devices can be envisaged, for example with slightly different wheel shapes (with buckets ..), as can be appreciated by those skilled in the art. The oil channeled into the receiving zone (50) is located at the high point (12) of the circuit and can then flow by gravity to the low point (11), by taking the dedicated paths in the cylinder head (1). The dead volumes are almost eliminated in the system lubrication system according to i.o the invention. As indicated by the arrow at the bottom of FIG. 1, the oil coming from the tank (2) or recirculated via the sloping channel (ch) is displaced by the conveyor wheel (4). The path (t1) illustrated in FIG. 1 shows the projection of the oil under the effect of the centrifugal force in the receiving zone (50) of the chute (G). Referring to Figure 3, the oil then takes a path (t2) in longitudinal chute (G) and can be distributed in branched channels (51, 52) connected to the chute (G). Some of these channels (51) extend into the cylinder head (1) above the camshaft (3) and stop to pour oil onto the bearings (32) of the shaft at least two times. cams. Other of these channels (52) extend over a longer distance and thus pour oil in particular on the camshaft rockers (3). Drip lubrication thus allows channels (52) to lubricate valve tails and rocker rolls locally.

As illustrated in FIGS. 3 and 4, the oil drop (s) (t3) can be made vertically on the local areas to be lubricated. Orifices (55) of the chute (G) may be provided to allow lubrication of areas placed under the chute (G). It is thus understood that the amount of oil required for lubrication is reduced and that the oil supply 3o is made in the relevant places. One of the advantages of the invention is that it makes it possible to provide the right amount of oil at each point of the distribution in the cylinder head. The cylinder head can be lubricated by means of an oil circuit that is completely separate from the high pressure oil line in the cylinder block and without the need for a specific oil pump. It therefore benefits for the cylinder head of a specific oil that ages less quickly since it is not polluted (no contact with the combustion gases that pass through the segmentation). One advantage of the invention is a reduction in the displacement of the oil pump, due to the decrease in the volume of oil under pressure. This makes it possible to feed only the low engine elements, in order to warm the oil of the lower engine more quickly. It should be obvious to those skilled in the art that the present invention permits embodiments in many other specific forms without departing from the scope of the invention as claimed.

Claims (16)

  A self-lubricating system for mechanical members of an engine cylinder head (1), characterized in that it comprises a lubricant circuit extending between a high point (12) and a low point (11) of the engine cylinder head, the high point (12) supplying lubrication to a piping system (5) for carrying out the lubrication, and conveying means (4, 42) for circulating the lubricant from said low point (11) to the high point ( 12) of the circuit, the pipe system (5) bringing the lubricant to at least one point in height above the organs to be lubricated.   2. System according to claim 1, wherein the means (4, 42) of transport comprise: guide means (42) for guiding lubricant upwards from a lubricant inlet zone (E) located at the low point (11); and - a movable part (4) having generally a gear shape and driven in rotation by drive means for conveying the lubricant on its periphery and along the guide means (42), to means (50) of receiving lubricant flush with the movable portion (4) and constituting said the high point (12).   3. System according to claim 2 or 3, wherein the movable part (4) is a toothed or paddle wheel, driven in rotation via a camshaft (3) introduced into the cylinder head (1).   4. System according to claim 3, wherein the circuit comprises a lubricant collector including a sloping channel (ch) formed in the cylinder head (1), this channel (ch) opening on an upstream side below the shaft cams (3) and a downstream side in the space where the wheel is housed.   5. System according to one of claims 2 to 4, wherein the means (50) for receiving lubricant comprises an upstream end of a chute (G) contiguous to a ceiling surface of a cover of the cylinder head.   6. System according to claim 5, wherein the chute (G) extends along a longitudinal axis of the yoke (1) and feeds via branches a plurality of local lubrication areas.   7. System according to claim 5 or 6, wherein the chute (G) distributes lubricant in channels of different section and / or inclination conveying lubricant, the lubricant flow being adjusted by sizing the section and the inclination of each channel.   8. System according to one of claims 1 to 7, wherein the pipe system (5) for performing the lubrication is downflow and is placed above the bearings of a camshaft (3) and valve shanks. and dispensing rollers.   9. System according to one of claims 1 to 8, wherein the lubricant circuit is devoid of lubricant pump and at least the pipe system (5) comprises sloping pipes to facilitate a flow of the lubricant.   10. System according to one of claims 1 to 9, comprising a lubricant reserve volume (2) communicating with the lubricant circuit at said low point (11).   11. System according to one of claims 1 to 10, wherein the lubricant circuit is divided in two in the cylinder head (1) as follows: a descending circuit part; and a lubricant ascending compartment (30) enclosing the transport means (4, 42).   12. Use of a conveyor wheel (4) in an engine cylinder head (1), characterized in that the rotational drive of the wheel (4) serves in a lubricant circuit to mount lubricant from a low point. (11) of the circuit to a high point (12) of the circuit, whereby the lubricant can flow from said high point (12) by gravity to lubrication areas of mechanical organs present in the cylinder head (1).   13. Use according to claim 12, wherein the conveyor wheel (4) is of the toothed or paddle type, placed at one end of a camshaft (3).   14. Cylinder head having an autonomous lubrication, characterized in that it comprises a lubricant circuit which is divided in two in the cylinder head (1) as follows: a descending circuit part; and lo - a lubricant ascending compartment (30) enclosing transport means (4, 42) including a rotatably driven wheel (4).   A cylinder head according to claim 14, wherein the downward circuit portion has a piping system (5) mounted or integrated on the underside of a cylinder head cover for feeding and dropping lubricant onto mechanical members present in the cylinder head. the breech (1).   The cylinder head according to claim 14 or 15, comprising a system according to one of claims 1 to 11.