FR2992362A1 - Cylinder casing for engine of car, has peripheral sealing sides extending approximately parallel to axis of crankshaft connected by lateral side, where one of peripheral sealing sides forms notch on longitudinal sides - Google Patents

Abstract

A cylinder block of a motor vehicle engine (1) equipped with a crankshaft (15) and comprising a lower portion delimited by a peripheral sealing edge (16-20) intended to be secured to a peripheral sealing edge of complementary shape to a peripheral sealing edge of an oil sump, said peripheral sealing edge (16-20) of the cylinder housing comprising longitudinal sides (16-19) extending substantially parallel to the crankshaft axis (15) connected by lateral sides (20), characterized in that said peripheral sealing edge has at least one indentation (21) on its longitudinal sides (16-19).

Description

The invention relates to the technical field of crankcases and oil pans associated therewith for thermal engines of motor vehicles in particular. The cylinder block, also called cylinder block, is the frame of the piston engine whose inner portion is machined to form the cylinders or the housing of shirts, if it is an engine shirts reported.

The cooling water circulates freely inside the crankcase. The upper part of the block is erected to form the joint plane for the cylinder head, which caps the cylinders The cylinder block performs various functions. It must withstand the pressure of combustion gases that tend to expand and push on the cylinder head. It must guide the piston, hence the need to reduce friction by sealing and increase wear resistance. It also guides the crankshaft by providing rigidity and alignment of the bearings, withstanding inertia and combustion forces and ensuring circularity and surface condition. Other requirements are required, such as the closing of the combustion chamber, ensure the holding of the cylinder head including the gasket cylinder and efficient evacuation of calories. The cylinder block must also support or usually incorporate different vehicle components, such as the oil pump, the water pump, the starter, the alternator, the injection pump, the air pump and the oil sump. This oil pan is disposed under the cylinder block, secured to the peripheral edge of a lower face of the latter, a peripheral seal ensuring the seal between the two housings. Different types of cylinder housings are commercially available and conventionally used. The cutting cylinder housings are distinguished at right angles to the crankshaft axis line, that is to say the so-called "cut to the axis" cylinders, where the peripheral edge of the bottom face of the crankcase is contained in a crankcase. plane containing the axis of the crankshaft and the "skirt" cylinder housings where the peripheral seal plane of the housing is offset relative to the crankshaft axis, located below the crankshaft axis.

Cylinders "cut to the axis" have the advantage of being economical in terms of cost and material used. However, in this configuration, the attachment of the gearbox on the engine must be able to be performed on a rigid zone but this causes well-known acoustic problems. To ensure increased acoustic performance, it is then required to implement a rigid oil sump, which is not in favor of improved economic requirements. Moreover, this implementation of a rigid oil sump makes it possible to guarantee a rotating seal of the crankshaft, this rotating seal being associated in part with the cylinder block and partly with the oil sump.

The skirted cylinder housings have a larger and more rigid coupling face which allows for a sufficiently rigid gearbox attachment without the need for a structural oil pan as well as a more reliable simplified rotary seal.

However, in order to constantly increase the performance and production costs and the operating costs of these crankcases, it is therefore sought to optimize the mass of the assembly and reliability. The optimization of the mass of the crankcase / oil pan assemblies is usually carried out by the use at least partially of the lowest possible density of metals and / or of suitable polymer material, especially in the manufacture of oil sump . However, the oil sump polymer material does not achieve the required acoustic performance on a cylinder block cut to the axis.

It is known that the hybrid oil sump (composed of several materials) can lighten the engine and thus improve the performance of the vehicle thus equipped. Hybrid aluminum and sheet metal oil pans are known, that is to say having a lower tray in relatively flat sheet and a complementary aluminum sole supporting the tray and fixed to the cylinder block. These housings can support vehicle components, such as the gearbox or the air conditioning compressor. Also known is a hybrid engine oil sump of a motor vehicle whose plastic tank is attached to a lightweight metal soleplate, the tray being intended to contain the engine oil in a relatively flat configuration and the sole being configured in a complementary manner in connection with the cylinder block, namely substantially parallelepiped rectangle. These housings can support vehicle components, such as the gearbox, and are lighter than the aluminum and sheet metal housings described above.

The patent application FR 10 61133 also describes the possibility of reducing the mass of crankcases by providing an engine oil sump having a soleplate and a tray. This soleplate is intended to be fixed to the cylinder block on the one hand and to the tank of the oil sump on the other hand, and is shaped to further support vehicle members. In order to overcome at least one of the disadvantages mentioned above, the invention relates to a crankcase of a motor vehicle engine equipped with a crankshaft and comprising a lower portion delimited by a peripheral sealing edge intended to be secured to a peripheral sealing edge of complementary shape of a peripheral sealing edge of an oil sump, said peripheral sealing edge of the cylinder housing comprising longitudinal sides extending substantially parallel to the axis of the crankshaft connected by lateral sides, characterized in that said peripheral sealing edge has at least one notch on its longitudinal sides. Thanks to this notch of the sealing edge positioned on the longitudinal sides parallel to the axis of the crankshaft, it is possible to reduce the mass of the crankcase to improve the production and use costs, while maintaining or by improving the acoustic performance and stiffness required in the attachment zones to the gearbox, namely the areas generally located on side faces of the cylinder block perpendicular to the crankshaft axis.

The cylinder block advantageously ensures the mechanical functions of the so-called low part, such as the docking of the gearbox and the attachment of the compressor. The crankcase is adapted to cooperate with an oil sump, said oil sump being usually placed below the cylinder block.

The cylinder block is not limited in shape and size.

According to preferred embodiments, the cylinder block is classically delimited by a plurality of outer faces, advantageously four in number, said faces preferably forming a substantially rectangular structure.

Among the plurality of faces, two faces, said side faces and extending substantially perpendicular to the crankshaft axis, respectively constitute a coupling face to the gearbox and a securing face to, in particular, a crankcase oil distribution, opposite to the coupling face.

The cylinder block has a so-called lower part and a so-called upper part, the periphery of said lower part being delimited by the sealing edge. The upper part of the cylinder block comprises on each longitudinal face typically the members or conventional elements of a drive cylinder, such as cylinders, pistons, camshaft, connecting rod chambers and the cylinder head. The lower part corresponds to a so-called lower part of the cylinder block extending substantially below the cylinder housings.

According to embodiments, the sealing edge defines at least one notch, which notch extends over at least a portion of the length of the longitudinal side of said sealing edge in a direction parallel to the axis of the crankshaft. The length of the longitudinal side of said sealing edge substantially represents the length of a longitudinal face of the cylinder block, extending from the coupling face to the gearbox to the securing face, in particular, to the housing of distribution. In order to optimize the desired effects and to simplify the production of the cylinder block, each longitudinal side of the sealing edge advantageously has a single notch extending over at least a part of the length of this longitudinal side. According to advantageous embodiments, said notch extends over at least 50% of the length of the longitudinal side of said sealing edge, preferably over at least 80% of the length, or even at least 90% to 95% of the length. the length. With this arrangement, the gain in production and operating costs by a user of a motor vehicle comprising the crankcase is increased.

Preferably, the notch of the sealing edge of the lower part may have any shape, provided that the desired effects are not altered. The indentation may define a non-planar shape, for example of the arches, circular arc, trapezoidal shape, according to slots and / or saw teeth, extending over at least a portion of the length of the edge of the edge. sealing. The notch can even define a sum of notches, called partial, disjoined them, according to the forms listed above. The sealing edge corresponding to a given lower part may thus have one or more indentations. According to advantageous embodiments, the indentation defines an inverted U-shape, said shape preferably comprising linear segments interconnected by rounded portions or forming angles at the ends of at least two segments.

In addition, the notch may define an inverted U shape, which may be flared, so that this shape preferably defines a trapezoidal shape, preferably having at the ends of the rounded portions. This particular form is that allowing to obtain the best desired effects. Advantageously, the depth of the notch of the sealing edge in a substantially vertical direction is such that the position of the bottom of the notch is at most at the same level or below the crankshaft. The cylinder block advantageously comprises a lateral coupling face to the gearbox and a lateral securing face to the timing case. Each side face has on its lower part fastening means arranged for securing the cylinder block respectively to the gearbox and the oil distribution casing, which does not exclude the securing to other conventional bodies of a motor. In order to ensure effective fastening, avoiding the movement of the integral members and while maintaining the desired effects, the fixing means may advantageously be provided with fixing points whose number is increased compared to the number of fixing points of a classic cylinder block. Therefore, additional fixing points can be arranged below the axis of the crankshaft between the crankcase and the gearbox or the crankcase and the timing case to improve the travel for example of the box of speed on the one hand and the seal between the crankcase and the crankcase on the other hand.

The number of additional fixing points between the crankcase and the gearbox allows a better joining resulting in an improvement of the reliability of the assembly including responding to frequencies of global modes of GMP depending on the engine harmonic which varies according to the number of cylinders of the engine. For a 3 cylinders for example, the harmonic to be considered is H1.5 (the frequency is of the order 168 Hz for example at the most critical maximum speed of 6000 rpm) and for a 4 cylinder the harmonic is H2 (The frequency is of the order of 200 Hz for example at the most critical maximum speed of 6000 rpm). With the additional fixing points, the natural frequency of the assembly is above the frequencies encountered during operation, which avoids resonance problems. On the side of the timing case, sealing is easier to achieve between the timing case coming to bear on the side surface of the crankcase instead of a part of the surface of the crankcase and a complementary part of the oil pan. According to particularly advantageous embodiments, the cylinder block is a skirted cylinder housing, comprising a coupling side face to a gearbox and a lateral side of attachment to an oil distribution housing, said side faces s' extending perpendicularly to the axis of the crankshaft, wherein the sealing edge extends below the axis of the crankshaft on the lateral faces of coupling and securing.

According to this embodiment, each longitudinal face of the cylinder block has at least one notch on its sealing edge, this notch being formed on the skirts of said skirted cylinder housing. The indentation is performed on the skirts which reduces the mass, so that the cylinder block has the desired effects. The depth of the notch of the sealing edge in a substantially vertical direction may be such that the position of the bottom of the notch is at most at the same level or below the crankshaft. Each end of the skirts has fastening means arranged for securing the cylinder block respectively to the gearbox and the oil distribution casing, which does not exclude securing to other conventional members of an engine.

The other parts or bodies of the crankcase are those usually encountered for this type of casing which is usually made of a metallic material and / or incorporating other materials for specific bodies.

The skirted cylinder housing of the invention comprises a lower portion delimited by a sealing edge intended to be secured to a complementary sealing edge of an oil sump. According to another aspect, the invention relates to an oil pan of a motor vehicle engine provided with a peripheral sealing edge of complementary shape of the peripheral sealing edge of a crankcase according to the invention. The oil sump is thus shaped to be positioned by its sealing edge against the sealing edge of the cylinder block defining an indentation on its longitudinal sides extending parallel to the axis of the crankshaft in a complementary manner, so that the sealing edge of the oil sump fills the surface of the notch. The oil sump is not limited in its shape and structure as they allow a reduction in its mass and that of the cylinder block to which it is intended to be secured. The oil sump can be formed of a single tank secured directly to the cylinder block, for example plastic material, in particular resistant polymer.

It is also possible to use aluminum and sheet metal hybrid oil pans, that is to say having a lower tray made of relatively flat sheet metal and a complementary aluminum base supporting the tank and fixed to the crankcase. These housings can support vehicle components, such as the gearbox or the air conditioning compressor.

It can also be a hybrid engine oil sump of a motor vehicle whose plastic tank is attached to a lightweight metal soleplate, the tray being intended to contain the engine oil in a relatively flat configuration and the soleplate being configured in a complementary manner in connection with the cylinder block, namely substantially rectangular parallelepiped. These oil pans can support vehicle components, such as the gearbox, and are lighter than the aluminum and sheet metal housings described above.

However, according to very advantageous embodiments, the tray is made of a plastic material which is very advantageously resistant polymeric material. The tray may be advantageously shaped with a plastic shell, which further lightens the tray relative to a sheet metal tray. The plastic material constituting the shell may be a conventional polyamide material but may be loaded with glass fibers, carbon fibers or the like to increase its mechanical strength. The shell is advantageously molded.

The shell may advantageously comprise at least part of the components associated with the treatment of the oil formed in one piece with the shell, such as oil circuit conduits and treatment members for circulation, decantation, filtration or the cooling of the oil, for example the oil supply line ducts with the integrated oil pump, the oil filter circuit ducts with the oil filter support member, the ducts of the oil circuit decantation of oil with settling chambers, heat exchanger circuits etc. Thus, it is not necessary to perform machining for these parts of the components as for the above known oil sump tanks.

In addition, it is easy to mold at least some of the parts of the associated components, for example the oil exchanger valve, oil level sensor, oil pump control connector, etc. The plastic shell may thus comprise, in addition to a part of the oil tank itself, extension parts in one piece with the shell, adapted to receive or at least partly constitute components associated with the treatment of the oil, for example, the oil circuit lines to the oil feed pump, the oil decantation circuit lines, the oil filter lines, the oil circuit lines to the exchanger etc., but also some of the parts of the associated components, for example the oil pump, the oil settling chambers and component support parts, while also ensuring the sealing of the various interfaces, such as by example the support member of the oil filter.

According to another aspect, the invention relates to a crankcase and oil pan assembly, characterized in that it comprises a crankcase and an oil pan, as defined above, said crankcases being assembled by their edges. respective sealing, complementary, a seal being interposed between these sealing edges. Thus, the assembly comprises a seal, for example elastomer, disposed between the cylinder block and the oil sump. Advantageously, this seal extends sealingly between the upper sealing edge of the oil sump and the lower sealing edge of the cylinder block. This seal can make it possible to seal the assembly. This seal also allows its cutting geometry in the space (not flat) to reduce the vibration of the housing device to the operation of the engine. The seal may be disposed above or below the oil level in the oil sump to maximize the use of plastic for weight gain. The invention is in no way limited by the shape of the joint profile, nor by the material or materials used. The seal may for example have a T-shaped profile, or other. The seal may be made of silicone elastomer, for example linear poly (dimethylsiloxane) or PDMS, and / or one or more other material (x). In addition, the support edges of the tray and / or the sole in contact with the elastomer seal may be left untreated, gross casting for the tray and raw casting for the sole. The plastic body of the tray body and the flexible elastomer seal absorb imperfections from the edge surfaces in contact with the seal. As a result, the machining of these surfaces, as in conventional hybrid oil sump, may be optional.

It is also proposed a motor vehicle engine comprising a crankcase assembly and oil pan, as described above. The invention will be described in more detail with reference to the figures in which: - Figure 1 is a schematic perspective view of a cylinder block according to one embodiment of the invention, on which the gearbox is visible (A ) and is not (B); (A) and (B) representing two different embodiments; - Figure 2 shows the same perspective view of Figure 1 with the incorporation of an oil sump; (A) and (B) representing two different embodiments; - Figure 3 is a perspective view of a half casing cylinders in section along the YZ plane passing through the crankshaft axis. In the present description, the terms of the cylinder block in section along the plane YZ passing through the axis of the upper crankshaft, lower, are defined with respect to the crankcase, when the axis of the crankshaft thereof extends in a horizontal plane. In an orthonormal coordinate system X, Y, Z, the Y axis extends parallel to the axis of the crankshaft of the cylinder block, the Z axis being vertical.

By substantially perpendicular or parallel means a direction / plane forming an angle of at most ± 200, preferably at most ± 100 with a direction / a plane perpendicular or parallel to another direction / another plane.

Figure 1 (A) shows a motor unit 1 comprising a cylinder block 10 and a gearbox 30. All the elements and constituent members of the engine block 1 have not been shown. The cylinder block 10 is here a cylinder block skirts insofar as the skirts that extend on the longitudinal faces 11,12, have been partially hollow, which defines the notch 21. The longitudinal face 12, opposite to the face 11, is not shown. The crankcase 10 here comprises three cylinders 12, a crankshaft 15. It is defined by four faces, two longitudinal faces 11, 12 and two lateral faces 13, 14, one of the lateral faces 13 being a coupling face to the gearbox 30, and the other side face 14 being a securing face to an oil distribution casing (not shown). The crankcase 10 has a so-called lower part, located under the cylinders 12, and a so-called upper portion located above this lower part. The periphery of the lower part being delimited by the sealing edge. This peripheral sealing edge comprises longitudinal sides extending substantially parallel to the crankshaft 15 connected by lateral sides. In the example, each longitudinal side is formed by straight segments 16, 17, 18, 19 connected by rounded corners and each lateral side is formed of a line segment 20. The longitudinal and lateral sides are connected by rounded corners.

The length of the longitudinal side of the peripheral sealing edge, corresponding to the segments 16, 17, 18, 19 extends over the entire length of the longitudinal faces 11, 12 considered. Similarly, each segment 20 of a lateral side extends over the entire width of a side face 13, 14 of the cylinder block 10. The peripheral sealing edge 18, 19 defines a notch 21 and here has a shape of U inverted, flared, trapezoidal shape of which two linear segments 19 connect the segment 18 by rounded ends. Here, the angle between the different segments 18, 19 is about 90 °. The segments 16, 17 are thus located on either side of the notch 21. The hatched area of FIG. 1 (A) represents the zone of the skirts which has been removed by defining the notch 21. The depth of the notch 21 of the peripheral sealing edge 18,19 in a substantially vertical direction is such that the position of the bottom 18 of the notch is at the crankshaft 15. The bottom portion 18 of the notch 21 corresponds to the limit the positioning of the skirts after removal thereof. The segments 16, 17 and 20 of the sealing edge extend in the same horizontal plane located under the crankshaft 15.

The notch 21 may extend over 70 to 95% of the length of the longitudinal side of the sealing edge. The remaining length of the sealing edges corresponding to the segments 16, 17. These thus extend over a length sufficient to ensure a predetermined rigidity to the lower parts of the lateral faces 13, 14, in particular with a view to the fixation of members of the motor.

In the example, the notch 21 extends 90 to 95% of the length of the longitudinal side, the segments 16, 17 extending 5 to 10% of the length of a longitudinal side. Figure 1 (B) shows another embodiment of the cylinder block 1 on which the gearbox 30 is not shown. Here, the same references have been preserved. This embodiment differs from the previous one only in that the linear segments 16-20 forming the sealing edge are connected by sharp angles.

FIG. 2 (A) shows a motor unit 1 comprising a cylinder block 10, an oil sump 40 and a gearbox 30.

All the elements and constituent members of the engine block 1 have not been represented. Here, the same references and arrangements to those of Figure 1 (A) have been retained for the crankcase 10.

The oil sump 40 shown is provided with a peripheral sealing edge formed by straight segments 16 ', 17', 18 ', 19', 20 'connected by rounded corners, of complementary shape to the edge of the seam. sealing device 16-20 of the crankcase 10. In this figure, the sealing edges 16, 16 '; 17, 17 ', 18, 18'; 19, 19 '; 20, 20 'are merged.

The peripheral sealing edge 16'-20 'of the oil sump 40 comprises longitudinal sides extending substantially parallel to the crankshaft 15 connected by lateral sides. In the example, each longitudinal side is formed by line segments 16 ', 17', 18 ', 19' connected by rounded corners and each lateral side is formed of a line segment 20 '. The longitudinal and lateral sides are connected by rounded corners. The oil sump 40 is positioned by its sealing edge 16'-20 'against the sealing edge 16-20 of the cylinder block 10 in a complementary manner, so that the oil sump fills the surface of the oil sump. 21. In this figure, the lower part of the tray 40 is not flat but extends downwards. A seal 41 is interposed between these sealing edges 16-20 and 16'-20 '. The oil sump 40 shown is formed of a plastic container, for example made by molding. Figure 2 (B) shows a motor unit 1 having a cylinder block 10 and an oil sump 40, said oil sump being arranged according to another embodiment.

Here, the same references and arrangements to those of Figures 1 (B) and 2 (A) have been retained for the crankcase. This embodiment differs from the embodiment shown in FIG. 2 (A) by the shape of the oil sump 40, which forms a flat-bottomed pan, and by the shape of the sealing edges, the 16 '-20' segments. ; 16-20 of each sealing edge being connected by sharp angles, corresponding to the embodiment of Figure 1 (B).

Figure 3 is a perspective view of a half cylinder casing 10 in section along the YZ plane passing through the crankshaft axis 15. The same references as those of Figures 1 and 2 have been retained.

The crank chamber fabric carries the reference 60 and the outer wall of the water chamber the reference 50. Each side face 13, 14 of the cylinder block comprises on its lower part 22, 23, fastening means arranged for the fastening the crankcase respectively to the gearbox and the oil distribution casing, which does not exclude securing to other conventional members of an engine. Thus, each end 22, 23 represents the ends of the skirts in the area of the longitudinal faces 11, 12.

Claims (10)

REVENDICATIONS1. Crankcase of a motor vehicle engine (1) equipped with a crankshaft (15) and comprising a lower part delimited by a peripheral edge (16-20) of the cylinder block comprising longitudinal sides (16-19) extending substantially parallel to the axis of the crankshaft (15) connected by lateral sides (20), characterized in that said peripheral sealing edge has at least one notch (21) on its longitudinal sides (16-19). The cylinder housing of claim 1, wherein each longitudinal side of the sealing edge (16-19) has a single notch (21) extending over at least a portion of the length of that longitudinal side. The cylinder housing of claim 1 or 2, wherein said notch (21) extends at least 50% of the length of the longitudinal side of said sealing edge (16-19). 4. Carter cylinders according to one of claims 1 to 3, wherein the notch (21) defines an inverted U-shape, said shape comprising linear segments (18,19) interconnected by rounded portions or forming angles at the ends of at least two segments (18,19). The cylinder housing of claim 4, wherein the inverted U shape is flared. 6. Cylinder casing according to one of claims 1 to 5, wherein the depth of the notch (21) of the sealing edge (16-19) in a substantially vertical direction is such that the position of the bottom (18) the indentation (21) is at most at the same level or below the crankshaft (15). 7. Cylinder casing according to one of claims 1 to 6, which is a casing with skirts cylinder, comprising a side face (13) of coupling with peripheral sealing (16-20) intended to be secured to an edge of complementary shaped peripheral seal (18 ', 19') of a peripheral sealing edge of an oil sump (40), said sealing edge a gearbox (30) and a side face (14) for securing to an oil distribution casing, said lateral faces (13, 14) extending perpendicular to the axis of the crankshaft (15), in which the sealing edge (20) extends under the axis crankshaft (15) on the faces (13,14) of coupling and securing. 8. Oil pan (40) of a motor vehicle engine (1) provided with a peripheral sealing edge (18 ', 19') of complementary shape to the peripheral sealing edge (18, 19) d a cylinder block (10) according to one of claims 1 to 7. 9. Crankcase assembly (10) and oil sump (40), characterized in that it comprises a crankcase (10) and an oil sump (40), as defined according to Claims 1 to 7 and 8, said housings (10,40) being joined by their respective sealing edges (16-20,16'-20 '), complementary, a seal (41) being interposed between these sealing edges (16-20, 16'-20 '). Motor vehicle engine (1) comprising a crankcase assembly (10) and oil sump (40) as defined in claim 9.