EP0771944B1 - Crank case for an internal combustion piston engine - Google Patents

Abstract

The casing has a metallic inner section (1) with cylinders (3,4). The inner section has integrally formed liners (5,6), consisting of the same material. The liners extend between an upper connection plane for the cylinder heads, and a plane, which is located between a lower connection plane and a cover plate (7). Cast stiffening bridges (17) are located in the area of the cover plate between the liners and the screw posts (8). The cover plate has a circumferential claw connection section (20), and a corresponding part of the outer casing section is cast around this.

Description

The invention relates to a housing for an internal combustion engine according to the preamble of claim 1.

A generic housing is disclosed in DE-34 36 872 C2. This housing for a single-row internal combustion engine has an inner part which is common to all cylinders and consists of gray cast iron and has a cover-like bottom. Adjacent to individual cylinders, screw pipes extend between an upper connection plane carrying a cylinder head and a lower connection plane receiving a longitudinal axis of the crankshaft.
The floor arranged between these levels is closer to the lower connection level and is surrounded in the longitudinal direction of the internal combustion engine by side webs arranged between the screw pipes and connected to it. Between two screw pipes arranged in a transverse plane of the internal combustion engine, a wall extends from this floor to the lower connection plane, which serves to support the crankshaft.
In the area of each cylinder, the floor has a circular recess, in which liners are inserted separately.
To achieve a housing that is as light as possible, this inner part is encapsulated by an outer part made of heat-resistant plastic with the formation of cooling water and oil-carrying spaces.

From EP-0 067 890 A1 it is known to provide a housing for a multi-cylinder internal combustion engine to be provided with plastic side walls. Here is that Housing essentially from a one-piece metallic frame Bushings, crankshaft bearings, a bottom and an upper, closed Deck (closed deck) and front side walls formed. This on his Structures that are open on the long sides are then formed by separately formed plastic side walls locked.

Furthermore, it is known from DE-43 06 269 A 1, the housing for a multi-cylinder Run internal combustion engine so divided that in an outer, trough-shaped Housing shell an integral part is screwed, which consists of a bottom with a circumferential flange and molded bushings as well as walls with crankshaft bearings.

CH-428 319 also includes an aluminum crankcase separately used liners known, the side walls for the purpose of reduction the noise emission caused by during the casting of the housing Metal plates are formed.

Finally, from DE-OS 17 51 919 is a one-piece cylinder block for one Internal combustion engine with cast crankshaft bearings and cast stud bolts for fastening a cylinder head known, the outer shell by attached Molded parts made of sheet metal or plastic.

The invention has for its object a generic housing for a To create reciprocating internal combustion engine with an inner and an outer part, which is largely free of distortion and as stiff as possible during operation of the internal combustion engine is. In addition, this case should be lightweight and acoustically favorable Damping properties is provided.

This object is achieved with the features of patent claim 1. Advantageous embodiments of the invention are specified in the dependent claims.

The main advantages of the invention can be seen in the fact that the inner part also integrally receives the liners, whereby additional connection points are avoided. All of the noise-causing or noise-transmitting components of the inner part are thus to be produced using the same material, for example, from a gray cast iron material which has favorable damping properties.
The essential further component of the housing, the outer part, can be made of a light metal material to reduce the weight of the entire housing, for. B. made of an aluminum or magnesium alloy, and thus has sufficient strength to absorb the forces and moments transmitted from the inner part to the outer part and vice versa, moreover, it is for the operating conditions prevailing in an internal combustion engine, in particular comparatively high temperatures and exposure to Oil or water ideally suited.
Alternatively, the outer part can be made of a lightweight plastic.

Advantageously, the screw pipes extend largely free-standing from the Bushings, so that those transferred by piston side forces to the liners Vibrations are not passed on via these screw pipes. Likewise, Vibrations originating from the crank mechanism by means of these screw pipes kept away from the bushings due to a continuous flow of power. The Bushings are therefore from the alternating forces between the cylinder head and crank mechanism transmitting power flow exempt and in this respect with little delay, which in turn z. B. has a positive effect on oil consumption, wear and blow-by gases.

In an advantageous embodiment, the screw pipes can come off the deck extend to the upper connection level, alternatively these can Screw whistles can also be carried out horizontally separately. Here is a part assigned to the inner part and extends from the deck in the direction to the upper connection level in such a length that a thread is introduced can be, the second part of the screw pipes is arranged in the outer part and is supported under direct contact with the section assigned to the inner part.

In an advantageous embodiment, irrespective of one-part or multi-part screw pipes, these can be connected to the deck and the bushings near the deck by means of stiffening bridges.
In order to achieve an optimally rigid bond between the inner and outer part, the deck has, in a further embodiment, a claw on its outer circumferential line, which is largely enclosed during the encapsulation with the material of the outer frame. For optimal absorption of longitudinal forces introduced into the housing, for example by means of a gear housing arranged at the end, this claw area can have a circumferential bead which, in a further embodiment, can be designed in a tooth-like manner in sections. In any case, this deck enables an unimpeded, even flow of force for these longitudinal forces, which in turn causes less warpage.

Furthermore, the deck can be in between the outer circumference and the liners area for the purpose of improved clawing by means of openings be penetrated by the material of the outer part.

In addition to the claws mentioned in the area of the deck, this housing can be used in other advantageous embodiment comparable claw areas on its upper or have lower end surface. For this purpose, those in the area below Connection level lying storage chairs for the crankshaft protruding further Have claw areas, which purpose in the longitudinal direction with each other Bracing can be connected.

The end faces of the one-piece screw pipes assigned to the upper connection level and / or the bushings can continue to this upper connection level have vertical toothing for improved clawing. When the inner and outer parts are joined together, these end faces become complete Poured by the material of the outer part, so that in the area of this upper connection level A cover surface of the same material is available for further processing. This is favorable for the cutting tools to be used and for the adjusting ones Chip flow and the recycling of these chips.

Basically, this housing can be designed as an open deck or closed deck become. Furthermore, the housing is in die casting, die casting or sand casting representable.

During the encapsulation of the inner part, a water jacket core can be arranged directly on the outside of the liners to produce a cooling water jacket, whereby an optimal heat transfer can be achieved.
As an alternative to this, the water jacket core can be arranged at a slight distance from the liners so that a comparatively thin layer of the outer part material is cast around them, thereby creating a self-contained, liquid-tight cooling water-conducting cavity.

Bearing caps held on the storage chairs are preferably made of the same Material, preferably gray cast iron, like the inner part. As a result, one is Cutting-edge production of the bearing lane for the crankshaft and in the operation of the internal combustion engine an extremely low bearing clearance can be achieved. Another bracing and Noise reduction can be achieved in that this bearing cap in the form of a integrally formed bearing bridge extending over the length of the housing are summarized.

Overall, the invention has the advantage that a low-warpage, rigid housing with very good running and damping properties with low weight is created. The usual effort due to the additional pressing is eliminated or pouring occasional liners or the complex processing of Cylinder running surfaces in so-called light metal engines.

In addition, it should be noted that the housing in the case of an in-line internal combustion engine or a VR engine with multiple cylinders has an inner part, while a V internal combustion engine can have its own inner part for each cylinder bank, which are then cast together by the outer part.

Figur 1 eine Draufsicht auf ein Innenteil eines Gehäuses,

Figur 2 eine Seitenansicht zu Figur 1,

Figur 3 eine Ansicht von unten auf ein Innenteil eines Gehäuses,

Figur 4 einen Schnitt entlang der Linie IV - IV gemäß Figur 1,

Figur 5 einen Schnitt entlang der Linie V - V gemäß Figur 1 durch ein Gehäuse,

Figur 6 einen Schnitt entlang der Linie VI - VI gemäß Figur 1 durch ein Gehäuse,

Figur 7 einen Schnitt entlang der Linie VII - VII gemäß Figur 1 durch ein Gehäuse,

Figur 8 einen Schnitt durch eine andere Ausführungsform ähnlich Figur 4 und

Figur 9 einen Schnitt durch die geänderte Ausführungsform ähnlich Figur 5.

Further advantages of the invention result from the exemplary embodiment explained in more detail below with reference to a drawing. Show it:

FIG. 1 shows a plan view of an inner part of a housing,

FIG. 2 shows a side view of FIG. 1,

FIG. 3 shows a view from below of an inner part of a housing,

FIG. 4 shows a section along the line IV-IV according to FIG. 1,

5 shows a section along the line V - V according to FIG. 1 through a housing,

FIG. 6 shows a section along the line VI-VI according to FIG. 1 through a housing,

7 shows a section along the line VII-VII according to FIG. 1 through a housing,

8 shows a section through another embodiment similar to Figure 4 and

9 shows a section through the modified embodiment similar to FIG. 5.

An internal combustion engine has a housing which is essentially formed from an inner part, designated overall by 1, and an outer part 2 cast around it.
The internal combustion engine has cylinders 3, 4 arranged along a longitudinal center plane L, which have bushings 5, 6.

The inner part 1 is made in one piece and of the same material from gray cast iron and consists essentially from the liners 5, 6, a deck 7, screw pipes 8 and Bearing 9 for a crankshaft, in transverse planes Q adjacent to the cylinders 3, 4 running walls 10.

According to Figure 2, the inner part 1 extends essentially between an upper Connection level A for a cylinder head, not shown, and a lower connection level B.

It should be noted that those used in connection with this invention Terms such as upper and lower refer only to the drawing figures and in particular no restriction with regard to a possible installation position of this housing mean.

The screw pipes 8 extend from the deck 7 into the area of upper connection level A, while the walls 10 are essentially from the deck 7 extend to the lower connection level B.

The sleeves 5 extend in their lower area to a level E lying between the deck 7 and the lower connection level B.
The screw pipes 8 have receptacles 11 and threads 12 for receiving screws (not shown) connecting a cylinder head to the housing.

Both sides of the bearing 9 are 10 threads 13 in each wall for fastening Crankshaft bearing caps 14 arranged, these made of the same gray cast iron material are made like the inner part 1.

Threads 13 and threads 14 can be axially aligned to improve the Force flow can be arranged, alternatively can from the bearing caps 14 to Continuous tie rods are used for the cylinder head.

An integral part of the inner frame 1 is adjacent to the deck 7 Main oil channel 15 extending in the longitudinal direction, of which, for example, transverse channels 16 to supply the bearings 9.

To achieve a rigid bond, 7 stiffening bridges 17 are cast between the screw pipes 8 and the bushings 5, 6 in the area of the deck.
In the transverse plane Q lying between the cylinders 3 and 4, the wall 10 is guided beyond the deck 7 in the direction of the upper connection plane A while leaving a cooling water passage 18.

To produce a positive locking in the transverse and longitudinal direction of the housing between the outer part 2 and the inner part 1, the deck 7 has on its outer circumferential line a claw area 20 which is largely encapsulated by the outer frame 2.
The claw area 20 has a bead 21 which extends at least in sections along the circumferential line of the deck 7 and extends to both sides of this deck 7 and which, as can be seen from FIG. 2, has a tooth-like shape 22.
In order to increase the clawing effect, the deck 7 according to FIG. 1 has openings 23 which are penetrated by the outer part 2 when the outer part 2 is cast around it.
Deviating from the design of the deck 7 shown in the figures, this can run significantly closer to the bushings 5, 6 or the screw pipes 8 and, in so far as it is less plate-like, as can be seen, for example, from FIG.

Another claw area 24 is on the bearing chairs 25 of the bearing 9 to the outside protruding in the form of struts 26 provided with an opening. This can, as shown in Figure 3, right half of the picture, by means of cast bridges 27 in Be longitudinally connected to each other.

To provide a claw in the area of the upper connection plane A, the bushings 5, 6 have a toothing 28 in the form of cast-in recesses 29 on their end face 30 facing the plane A.
An identical claw can be provided on the corresponding end faces 31 of the screw pipes 8.
These end faces 30, 31 are completely encapsulated by the outer part material according to FIGS. 5 and 6, so that a cover surface 32 of the same material as that facing the cylinder head is created.

During the encapsulation of the inner part 1, a water jacket core 35 can be arranged at a slight distance from the liners 5, 6 in such a way that they are surrounded by a comparatively thin layer 36.
Alternatively, this water jacket core 35 can also be arranged directly on the liners 5, 6.

To provide uniform cooling on the circumference of the sleeves 5, 6 can a water jacket 37 between the screw pipes 8 and the liners 5, 6th be carried out, with the screw pipes 8 for this purpose according to FIG Flattenings 38 can be provided.

A finished housing, formed from inner part 1 and outer part 2, can best be seen from FIG. 5, wherein there is a gear flange 40 formed integrally with the outer part 2 for connecting a gear unit to the housing. The claw area 20 and struts 26 are encapsulated by the outer part material, ribs 41 provided with openings in the area of the walls 10 and the bearings 9 being provided for further stiffening of the entire housing.
FIG. 5 also clearly shows the manner in which the deck 7 and the outer walls 42 of the outer part 2 delimit an oil-carrying space in the region of the crank mechanism, while above the deck 7 cooling water-carrying spaces are designed in the form of the water jacket 37.

An embodiment modified with regard to the design of the screw pipes 8 is shown in FIGS. 8 and 9. Here, the screw pipes 8 are of split design, a lower part being designed as a threaded piece 81 belonging to the inner part 1 and an upper part being formed as supports 82 having the receptacles 11 and belonging to the outer part 2.
The threads 12, in which the cylinder head screws can engage, are formed in the threaded slug 81.
The threaded slugs 81 and the supports 82 form a shoulder-like system 83, so that an unimpeded, continuous flow of force is also ensured here.
In the case of an open-deck construction, this embodiment offers improved conditions for the encapsulation of the bushings 5.
Furthermore, a further claw area 84 can be seen in these figures in the transverse planes having the storage chairs 25.

Claims (17)

1. Housing for a reciprocating internal combustion engine, having at least one metal inner part (1) which is formed in one piece, comprises at least one cylinder (3, 4) and comprises a deck (7) with screw pipes (8) which are integrally formed thereon and extend in the direction of an upper connection plane (A) for a cylinder head, wherein walls (10) which start adjacent to the cylinder (3, 4) extending in transverse planes (Q) from this deck (7) extend as far as to a lower connection plane (B) and comprise bearing blocks (25) for a crank shaft, and having an outer part (2), which is cast around the inner part (1), forms chambers carrying cooling water and oil and consists of a material which is different to the inner part (1), characterised in that bushings (5, 6) are formed in one piece with and in the same material as the inner part (1).
2. Housing according to claim 1, characterised in that the bushings (5, 6) extend between the upper connection plane (A) and a plane (E) lying between the deck (7) and the lower connection plane (B).
3. Housing according to claim 1 or 2, characterised in that cast-on stiffening bridges (17) are disposed between the screw pipes (8) and the bushings (5, 6) in the region of the deck (7).
4. Housing according to claim 1, characterised in that the deck (7) comprises on its peripheral line a clasping region (20) which has a corresponding region of the outer part (2) cast substantially around it.
5. Housing according to claim 4, characterised in that outwardly protruding, further clasping regions (24) are disposed on the bearing blocks (25).
6. Housing according to claim 4 or 5, characterised in that a peripheral bead (21) extends at least in sections along the peripheral line.
7. Housing according to any one or several of the preceding claims 4 to 6, characterised in that the peripheral line comprises at least in sections a shape (22) in the form of a toothing arrangement.
8. Housing according to any one or several of the preceding claims 4 to 7, characterised in that in the clasping region (20) the deck (7) comprises openings (23) which have the outer part material passing through them.
9. Housing according to claim 5, characterised in that the further clasping regions (24) are connected to each other in the longitudinal direction of the housing by means of cast-on bridges (27).
10. Housing according to claim 1, characterised in that end faces (30, 31), facing the upper connection plane (A), of the inner part (1) have the outer part material cast around them in such a manner as to produce a cover surface (32) in the same material and facing the cylinder head.
11. Housing according to claim 10, characterised in that at least one of the end faces (30, 31) has a toothing arrangement (28) extending in a perpendicular manner with respect to the upper connection plane (A).
12. Housing according to claim 1, characterised in that during the process of casting-around the inner part (1) a water cooling jacket core (35) is disposed directly on the bushings (5, 6).
13. Housing according to claim 1, characterised in that during the process of casting-around the inner part (1) a water cooling jacket core (35) is disposed slightly spaced apart from the bushings (5, 6).
14. Housing according to claim 1, characterised in that the bearings (9) of the crank shaft comprise bearing covers (14), of which the screw connections arranged on both sides of a longitudinal middle plane (L) of the housing are disposed in a flush manner with the screw pipes (8).
15. Housing according to claim 1 or 14, characterised in that the bearings (9) of the crank shaft comprise bearing covers (14) which are interconnected in a bridge-like manner in the direction of a longitudinal middle plane (L), wherein said bearing covers are manufactured from the same material as the inner part (1).
16. Housing according to claim 1, characterised in that the screw pipes (8) extend starting from the deck (7) as far as to the region of the upper connection plane (A).
17. Housing according to claim 1, characterised in that the screw pipes (8) are formed in a divided manner such that one part provided as the threaded slug (81) is allocated to the inner part (1) and a further part provided as the support (82) is allocated to the outer part (2).

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