FR2849467A1 - ANTI-EMULSION PLATE FOR RIGIDIFYING THE WALLS OF A MOTOR VEHICLE OIL PAN - Google Patents

Abstract

The invention relates to an internal combustion engine of a motor vehicle, comprising: - a lower oil pan (12) in the form of a tray which comprises a base (18) from which extend substantially vertical walls (20); - an upper cylinder block (10) comprising a lower skirt (14), the lower perimeter of which is fixed to the upper edge (21) of the walls (20) of the oil pan (12); of the type which comprises an anti- substantially horizontal emulsion (30) comprising oil flow orifices (32, 38) which is fixed inside the oil pan (12), and which divides the oil pan (12) into one upper chamber (31) and a lower oil tank (33), characterized in that the anti-emulsion plate (30) is fixed to the walls (20) of the oil pan (12) and in that it is made of a rigid material.

Description

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  "Anti-emulsion plate to stiffen the walls of a motor vehicle oil pan" The invention relates to an internal combustion engine of a motor vehicle which comprises an oil pan, a block5 cylinders and a horizontal plate called "anti -emulsion".

  The invention relates more particularly to an internal combustion engine of a motor vehicle comprising a lower oil pan in the form of a tank which comprises a bottom from which extend substantially vertical walls, and 1o comprising an upper cylinder block which comprises in particular a lower skirt, the lower perimeter of which is fixed to the upper edge of the walls of the casing, of the type comprising a substantially horizontal anti-emulsion plate which comprises oil flow orifices, which is fixed inside the casing, and which divides the casing into an upper chamber between the upper edge of the walls and the anti-emulsion plate, and a lower oil reservoir included between the anti-emulsion plate and the bottom.

  The oil pan is tightly fixed under the cylinder blocks. This integral assembly is also called "low-engine". The lower skirt of the cylinder block is situated substantially in the continuity of the vertical walls of the casing.

  The operation of the engine produces vibrations which are propagated in particular by bending of the lower skirt of the cylinder blocks and of the walls of the oil sump. For certain engine operating speeds, these vibrations have an amplitude capable of creating parasitic noise in the engine.

  To reduce parasitic noise, it is known to stiffen the lower skirt of the cylinder block and / or the walls of the oil pan. It is notably known to produce the oil pan in a first lower part in the form of a tank, and in a second upper annular section forming upper vertical walls of the oil pan. The second annular section is also called "casing sole".

  This second annular section is rigid enough to prevent the propagation of vibrations of large amplitude between the cylinder block and the lower tank-shaped part of the oil pan. However, the structure of this second annular section cannot generally be dimensioned so as to obtain optimum efficiency. Indeed, problems of space and geometric interference with elements adjacent to the oil pan constrain the design of such a part.

  In addition, this part must be fixed, on the one hand, by its upper edge to the lower wall of the skirt of the cylinder block, and, on the other hand, to the lower part of the oil pan. It is therefore necessary to make a first upper seal between the cylinder blocks and the second section, and a second seal between the second section and the lower part of the oil pan. Such a design is therefore expensive.

  It is also known to insert a horizontal stiffening plate between the bottom of the cylinder block and the top of the oil pan. This type of stiffening plate prevents the bottom of the lower skirt of the cylinder blocks from vibrating during engine operation.

  However, such a stiffening plate is not effective enough to prevent the walls of the oil pan from vibrating for certain engine operating speeds.

  In addition, the stiffening plate being interposed between the cylinder blocks and the oil pan, it is necessary to carry out sealing operations between, on the one hand, the oil pan and the plate, and, on the other hand, the cylinder block and the plate. Thus, the operation of mounting such a plate is complex and expensive.

  It is also known to fix a horizontal stiffening plate at the bottom of the cylinder block, but without this plate being interposed between the oil pan and the cylinder block. Thus, only one seal is necessary between the cylinder block and the oil pan. Such a plate is also called a "windage tray".

  However, mounting such a plate does not prevent the oil pan from vibrating for the same reasons as the previous solution.

  In order to solve this problem, the invention provides an engine of the type described above, characterized in that the anti-emulsion plate is fixed to the walls of the oil pan and in that it is made of a rigid material.

  According to other characteristics of the invention - the anti-emulsion plate is a thick metal plate - the anti-emulsion plate has horizontal stiffening ribs; the anti-emulsion plate is fixed to internal bosses made integrally with the walls of the casing by means of fixing screws with a vertical axis; Other characteristics and advantages of the invention will appear during the reading of the detailed description which will follow for the understanding of which one will refer to the appended drawings among which: - Figure 1 is a cross-sectional view of a moped comprising an upper cylinder block equipped with a first stiffening plate, and comprising a lower oil pan equipped with a second anti-emulsion plate produced in accordance with the teachings of the invention; - Figure 2 is a top view of the first stiffening plate of Figure 1; - Figure 3 is a top view which shows the oil pan of Figure 1 equipped with the anti-emulsion plate.

  We will adopt in the following description, without limitation, a longitudinal, vertical and transverse orientation according to the direct trihedron L, V, T of the figures.

  FIG. 1 shows the lower part of an internal combustion engine of a motor vehicle. This lower part is also called "low-engine". The lower part of the engine mainly comprises an upper cylinder block 10 and a lower oil pan 12.

  The cylinder block 10 generally includes cylinders (not shown) in each of which a piston of the engine is slidably received. The cylinder block also has longitudinal bearings (not shown) in which the crankshaft (not shown) is rotatably mounted.

  The upper cylinder block 10 includes in particular a generally vertical lower skirt 14 which is shown in FIG. 1. The lower perimeter of the lower skirt 14 defines a peripheral horizontal edge 16 under which the oil pan 12 is fixed.

  The lower oil pan 12 generally has the form of a tank comprising a bottom 18 slightly inclined relative to the transverse direction.

  The oil pan 12 has substantially vertical walls 20 which extend from the bottom 18 upwards. In known manner, the upper edge 21 of the walls 20 of the oil pan 12 is fixed under the peripheral edge 16 of the cylinder block 20 10 for example by means of screws with vertical axis A. The bottom 18 and the walls 20 of the oil pan 12 have ribs 22 for stiffening the oil pan 12.

  The oil pan 12 is in particular intended to contain the oil necessary for the lubrication of the movable elements of the engine. This oil is pumped from the oil pan to the moving parts of the engine. The used oil then flows by gravity from the movable elements to the oil pan in which it is recovered.

  In known manner, the lower skirt 14 of the cylinder block 30 10 comprises stiffening means which here consist of a perforated plate 24 substantially horizontal. This perforated plate 24 is also called "windage tray".

  As shown in FIG. 1, the stiffening plate 24 is fixed under the peripheral edge 16 of the skirt 14 of the cylinder block 10, for example by means of screws with vertical axis B. As shown in FIG. 2, it here acts of a plate 24 of thick sheet metal having holes 26 intended to allow the flow of oil from the cylinder block 10 to the oil sump 12. Advantageously, the plate 24 extends between the walls 20 sump 12 without being pinched between the lower peripheral edge 16 of the cylinder block 10 and the upper edge 21 of the oil pan 12. Thus, the seal between the oil pan 12 and the cylinder block 10 can be ensured by sealing means located for example in a groove 28 of the upper periphery 21 of the oil pan 12.

  The oil pan 12 comprises an anti-emulsion plate 30 which extends generally parallel to the bottom 18 of the oil pan 15 substantially to the walls 20 of the oil pan 12.

  The anti-emulsion plate 30 is here generally fixed at the height of the walls 20 of the oil pan 12 so as to divide the oil pan 12 into an upper flow chamber 31 and into a lower oil tank 33.

  There is shown more precisely in Figure 3, the anti-emulsion plate 30 according to the teachings of the invention.

  The walls 20 of the oil pan 12 have vertical bosses 34 which are five in number here and which are regularly distributed over the wall 20, inside the oil pan 25. The bosses 34 are produced from material with the walls 20, and they each comprise an upper horizontal face 36 on which the anti-emulsion plate 30 bears downwards. The anti-emulsion plate 30 is fixed to each of the bosses 34 for example by means of screws with vertical axis C. According to the teachings of the invention, the anti-emulsion plate 30 is made of a rigid material, for example a thick plate of metal such as steel. Such an anti-emulsion plate 30 thus fixed on the bosses 34 stiffens the walls 20 of the oil pan 12.

  According to a variant not shown of the invention, the anti-emulsion plate 30 has horizontal ribs which are intended to increase its overall rigidity of the plate 30, and therefore to increase the rigidity of the walls 20 of the oil pan 12.

  The anti-emulsion plate 30 here has a central orifice 32 and it is positioned so that one day remains 38 between the lateral edge 39 of the plate 30 and the wall 20 of the oil pan 12. The plate comprises small gradients in order to allow a slow flow of the oil from the upper flow chamber 31 to the lower tank 33 via the central orifice 32 and the day 38.

  Used oil is received on the plate in the form of an air and oil emulsion. The flow of oil on the anti-emulsion plate must be slow enough for the emulsion to settle and for the air and oil to separate.

  During the operation of the engine, vibrations, due for example to the sliding of the pistons or to the rotation of the crankshaft, propagate in particular in the lower skirt 14 of the cylinder block 10 and in the walls 20 of the oil sump 12.

  Thanks to the combination of the stiffening plates 24 and anti-emulsion 30, the amplitude of the vibrations which pass through the walls 20 and 14 of the engine is lower, which attenuates parasitic noise.

Claims (4)

  1. Internal combustion engine of a motor vehicle, comprising: - a lower oil pan (12) in the form of a tank 5 comprising a bottom (18) from which extend substantially vertical walls (20); - An upper cylinder block (10) comprising a lower skirt (14) whose lower perimeter is fixed to the upper edge (21) of the walls (20) of the oil pan (12); - a substantially horizontal anti-emulsion plate (30) comprising orifices (32, 38) for draining the oil which is fixed inside the oil pan (12), and which divides the oil pan (12) in an upper chamber (31) between the upper edges of the walls (20) and the anti-emulsion plate (30), i5 and a lower oil tank (33) included between the anti-emulsion plate (30) and the bottom (18), characterized in that the anti-emulsion plate (30) is fixed to the walls (20) of the oil pan (12) and in that it is made of a rigid material.   2. Motor according to the preceding claim, characterized in that the anti-emulsion plate (30) is a thick metal plate. 3. Motor according to any one of the preceding claims, characterized in that the anti-emulsion plate (30) has horizontal stiffening ribs.   4. Motor according to any one of the preceding claims, characterized in that the anti-emulsion plate (30) is fixed on internal bosses (34) made integrally with the walls (20) of the casing (12) by means of vertical axis fixing screw.