EP0688946B1 - Cylinder head layout of an internal combustion engine - Google Patents

Description

The invention relates to a cylinder head arrangement according to the preamble of Claim 1.

DE 41 16 942 C1 is a generic cylinder head arrangement shown in which a basic housing is placed on a cylinder block and with this is screwed. The basic housing has raised outer walls which has a hood-like lid. In the through the cylinder head cover and the raised outer walls of the basic housing The interior is a tappet housing at a distance from the outer walls arranged, which is screwed to the basic housing. The Cup tappet housing is formed in several parts and has in one The basic element is the guides of the valve cups and the lower half of the bearing block for storing the camshafts. On this lower half of the pedestal separate upper bearing block halves are attached and screwed to the lower parts.

From Volvo Service Manuel No. TP 317 14/2, page 11, is for the engine type B6304 a cylinder head is known in which the mounted on the cylinder block Basic housing in one piece with bucket tappet guide and the lower parts of Camshaft bearings is formed. On this basic housing is a Cylinder head cover bearing upper parts attached.

To achieve an optimal, especially high-strength combustion chamber side Material structure, it is desirable to do this by a largely to achieve undercut-free casting process, such as with the generic state of the art is possible. Training the with the Basic housing screwed bucket tappet housing according to the prior art however, requires a lot of assembly work, due to the large number the screw connections. Furthermore, there is a high manufacturing and Repair effort due to the storage of the camshafts in Bucket tappet housings, as these bearing bores are fixed during manufacture Require relation between bucket tappet housing and basic housing.

As a result, repairs and replacements are also fixed Assignment between bucket tappet housing and basic housing required.

The invention is therefore based on the object of a generic To improve cylinder head assembly in that both a high strength Material structure in particular of the basic housing can be achieved that the entire cylinder head assembly has a high overall rigidity and is easy to manufacture and assemble.

This object is achieved with the characterizing features of Claim 1 solved.

Further advantageous embodiments of the invention result from the Subclaims and the description.

If with such a cylinder head arrangement, the storage of Camshafts between the basic housing and the cylinder head cover occur and that Bucket housing is formed in one piece and only for guiding the Serves valve cups, result in easy to manufacture, easy to assemble Components that have a high overall rigidity when assembled. The assembly of the three individual elements of the basic housing, The tappet guide and cylinder head cover can be used with a small number of screw connections. This also results in a very compact design of the cylinder head assembly, which for a cylinder head overhead camshafts and tappets have a relatively low overall height and above all has a small overall width. With such training the cylinder head assembly, the cylinder head cover and that Cup tappet housings are manufactured, for example, as die-cast components. The Basic housing of the cylinder head assembly can be advantageously in Create permanent mold, using only those necessary for the water flow Channels (with water-cooled cylinder head) through molding sand or similar cast or Molding techniques must be created. At the same time it results from this three-part design of the cylinder head arrangement only a single one to the outside separating plane to be sealed, so that an oil leak with comparatively simple Means to prevent.

The overall rigidity of the cylinder head assembly in the assembled state can be increase in an advantageous manner if the bearing blocks each with the adjacent outer walls are connected, d. H. if the top Bearing block halves with the respective adjacent outer wall of the Cylinder head cover and the lower half of the bearing block with the adjacent outer wall of the basic housing are connected.

There are essentials for the manufacture of the cylinder head arrangement Simplifications when the connection between the cylinder head cover and Basic housing lies in a parting plane and this parting plane with the Parting plane of the bearing block halves corresponds.

The assembly of the cylinder head assembly can be considerably simplified if at least the screw connection between the cylinder head cover and the basic housing in the area of the cylinder bores by screwing the Bearing block halves done. This results in a significant reduction in Screwing points. At the same time, the width of the Cylinder head arrangement is reduced, since there is no one for this outdoors Connection required screw connections are more necessary.

A cheap, high-strength screw connection between the cylinder head assembly and Cylinder block results when four cylinder bores in one per cylinder Rectangular cylinder screws are provided. It is it is advantageous if there is sufficient space between the respective Cylinders such as those found in engines in boxer configurations is, between two cheese head screws of the adjacent A bearing block is arranged in cylinder bores.

Manufacturing and assembly of the camshaft bearings are to a high degree simplified if the storage on one end of the cylinder head arrangement the respective camshaft is carried out by a single bearing block. Through this Single bearing blocks can be depressed when installing the camshafts against the action of the valve springs. Particularly beneficial for the Training and manufacturing of camshaft bearings is when through this Single bearing blocks, the camshafts are guided axially.

The arrangement of the individual bearing blocks is advantageously carried out in the area for chain boxes required to drive the camshafts. The holes of the Camshaft bearings can then from the opposite end of the Cylinder head assembly are made so that these openings in the Front side when mounting the camshafts as an engagement for one Can be used to depress the camshafts.

The connection between the tappet housing and the basic housing is made Advantageously in a parting plane, in the favor of manufacturing technology Way channels for the oil guide can be poured. With that the required drilling effort for the oil guide significantly reduced. over these cast oil channels can be lubricated with just a few holes Valve cups and the camshaft.

Both manufacture and sealing of the cylinder head arrangement can be improve if the shaft opening into the combustion chamber for receiving a Spark plug or an injector extended by a sleeve and is sealed between the tappet housing and cylinder head assembly is inserted. This sleeve can be easily and easily installed insert and seal in an annular extension in the tappet housing.

The invention is based on the following description and drawing exemplified in more detail.

Fig. 1

eine Draufsicht auf das geöffnete Grundgehäuse der Zylinderkopfanordnung,

Fig. 2

eine Draufsicht auf das Tassenstößelgehäuse,

Fig. 3

einen Querschnitt durch die Zylinderkopfanordnung durch die Brennraummitte eines Zylinders entlang der Linie III-III gemäß Fig. 1,

Fig. 4

einen weiteren Querschnitt im Bereich eines Lagerbockes entlang der Linie IV-IV nach Fig. 1,

Fig. 5

einen weiteren Querschnitt im Bereich der Ventilführung eines Zylinders entlang der Linie V-V gemäß Fig. 1,

Fig. 6

einen Längsschnitt durch einen Teil des Grundgehäuses entlang der Linie VI-VI nach Fig. 1.

Show it

Fig. 1

a plan view of the open base housing of the cylinder head assembly,

Fig. 2

a plan view of the tappet housing,

Fig. 3

2 shows a cross section through the cylinder head arrangement through the combustion chamber center of a cylinder along the line III-III according to FIG. 1,

Fig. 4

4 shows a further cross section in the area of a bearing block along the line IV-IV according to FIG. 1,

Fig. 5

2 shows a further cross section in the region of the valve guide of a cylinder along the line VV according to FIG. 1,

Fig. 6

a longitudinal section through part of the basic housing along the line VI-VI of FIG. 1st

An internal combustion engine has one placed on a cylinder block 1 Cylinder head arrangement, the housing of three housing components is composed, a basic housing 2, a tappet housing 3 and a cylinder head cover 4. The internal combustion engine is in this Embodiment in the form of a cylinder bank of a six-cylinder Boxer engine with four valves per cylinder and two overhead Camshafts shown. This internal combustion engine accordingly has Cylinder bank three cylinder bores 5, which according to the one selected in FIG. 1 Representation as left, middle and right cylinder or corresponding Cylinder bore 5 are designated. Each of these cylinder bores 5 is about four disc springs (not shown) guided in valve guides 6 (two Intake valves, two exhaust valves) and corresponding gas exchange channels 7 controlled. The gas exchange channels 7 and valve guides 6 are in one Base block 8 of the basic housing 2 integrated, on the front side a chain case 9 connects. This serves to accommodate drive means, not shown for the timing drive. Go from the basic block 8 of the basic housing 2 Outer walls 10, 11 and 12 made opposite an inner support surface 13 are pulled up to a parting plane T-T. The chain case 9 is from Enclosed outer walls 14, which also extend to the parting plane T-T and connect to the walls 10 and 12 of the base block 8.

In the basic block 8 of the basic housing 2, three shafts 15 are formed each start from the support surface 13 and into one of the three cylinder bores 5 lead. The axes of the three shafts 15 lie in a central longitudinal plane M. and are used to hold one spark plug 16. You can also, especially for self-ignition engines, to accommodate injection devices or glow plugs. Each of these shafts 15 is of an annular shape poured recess 17 surround the part of the oil guide of the Cylinder head is. The annular recess 17 in the area of the left cylinder is connected to a likewise cast-in longitudinal groove 18, which does not refer to illustrated manner is connected to the oil supply to the cylinder head assembly. This longitudinal groove 18 runs approximately parallel to the central longitudinal plane M. Die are annular depressions in the area of the middle and right cylinder connected by a further cast longitudinal groove 19, the is also connected to the oil supply to the cylinder head assembly and approximately runs parallel to the median longitudinal plane M. The annular depressions 17 and the longitudinal grooves 18 and 19 are each surrounded by a sealing web 20, whose sealing surface is part of the support surface 13. The annular depressions 17th are each within one through the passage openings of the valve guides 6 in the base 13 formed rectangle, the shorter sides parallel to the median longitudinal plane M. The valve guides 6 are each against this Inclined plane and arranged in two rows.

The basic housing 2 is screwed to the cylinder block 1 in two Rows, i.e. the screw connections are each in a plane E1 or E2 parallel to the median longitudinal plane M. The screw connections 21 between Basic housing 2 and cylinder block 1 and the following in more detail Further screw connections explained are here for the sake of a better overview only represented by their holes. There are 5 for each cylinder bore four screw connections 21 are provided, the connecting lines of which are a rectangle form, which includes the valve guides 6. That through the four screw connections 21 rectangle formed per cylinder has its shorter sides parallel to Median longitudinal plane M.

In the basic block 8 of the basic housing 2 are still each camshaft or Valve row four lower bracket halves 22 arranged. Each lie the lower half of the bearing block of the two rows of valves opposite each other. A first pair of bearing blocks 22 is arranged in the area of the chain case 9, a second pair of bearing blocks 22 is located in the area of the opposite outer or end wall 11 and two further pairs of Bearing block halves 22 are located between the left and middle cylinders or between the middle and right cylinder. These two pairs of Bearing block halves 22 are each between two adjacent ones Screws 21 of the adjacent cylinder bores 5 are arranged. In each of the lower bracket halves 22 are two holes 23 for Screw connection with the upper ones described in more detail below Bearing block halves attached. These holes 23 are arranged so that the camshaft to be inserted lies between them. Four rows or Levels of screw connections or bores 23 formed in the in Fig. 1st Alignment of the basic housing 2 shown from top to bottom with B1 to B4 are designated. Hole level B1 is above level E1 the screw connections 21 and the bore level B2 lie below this Level. Both hole levels B1 and B2 lie above the middle level M. The hole planes of the lower row of bearing block halves are B3 and B4 referred to, the bore level B3 is above and the bore level B4 below the level E2 of the screw connections 21.

Each between the screw connections 21 lying in a plane E1 or E2 Cylinder bore 5 is a further screw 24, through which Bucket housing 3 and the basic housing 2 connected to each other will. The screw connections 24 of the tappet housing 2 are in two levels T1 and T2 parallel to the central level M. The upper level T1 lies between the bore plane B1 facing the outer wall 10 and the Level E1 of the screw connections 21, the lower level T2 lies between the lower level E2 of the screw connections 21 and that of the outer wall 12 facing bore plane B4 of the bearing block halves 22. A third row of Screws 25 for the tappet housing 3 is in the Central longitudinal plane M. For better sealing of the cast oil channels additional screw connections 26 are provided in the area of the sealing webs 20.

The tappet housing 2 is on the support surface 13 of the basic housing 2 its base 27 so that the bores or Continue screw connections 24 to 26 accordingly. The tappet housing 2 includes 5 four tappet guides 28 per cylinder bore, which with the respective axes of the valve guides are aligned. The four tappet guides 28 per cylinder are interconnected. Each of this group of four Cup tappet guides 28 are connected to the adjacent group of webs 29 Bucket guides 28 connected so that the whole bucket housing is formed in one piece. Within each of the four tappet guides Cylinder bore limited space, a bore 30 is provided with the shaft 15 is aligned. Each of these holes is on the top of the Cup tappet housing 2 surrounded by an annular extension 31. In the Base area 27 of the tappet housing 3 is one for each bore 30 surrounding annular groove 32 formed together with the annular Recess 17 in the support surface 13 forms an oil channel. The annular groove 32 in The area of the left cylinder bore is connected to a longitudinal groove 33, which in a longitudinal web 34 is arranged and with the longitudinal groove 18 in the basic housing 2nd forms an oil channel. The ring grooves 32 in the middle and right Cylinder bores are also connected to one another via a longitudinal groove 34, which interacts with the corresponding longitudinal groove 19 in the basic housing 2 and is cast into a longitudinal web 36. The oil supply to the Bucket tappet guides are made via oblique bores 46 which extend into the annular groove 32 flow out.

The cylinder head arrangement is covered by a cylinder head cover 4 completed in the area of the parting plane T-T on the outer walls 10 to 12 and 14 of the base housing 2 is placed and the bucket tappet housing 3 covered. The cylinder head cover contains three pairs of top Bearing block halves 37, each with the between the left and middle Cylinders, the middle and right cylinders and those in the area of the right End and outer wall 11 arranged lower bracket halves 22nd work together. These upper bracket halves 37 each go from one Outer wall of the cylinder head cover 24 or are integral with this connected. The screw connection between basic housing 2 and Cylinder head cover 4 takes place in the area of the base block 8 through the Screw connection 23 of the bracket halves. Only in the area of the chain case 9 are additional screw connections 38 in the area of the outer walls 14 intended. In the cylinder head cover 4, three holes 39 are arranged each aligned with one of the shafts 15. In these holes 39 are sleeves 40 inserted into the annular extension 31 of the tappet housing 3 protrude and there and in the area of bore 39 each through sealing rings 41 or 42 are sealed. These sleeves 40 extend or seal the shaft 15 or the bore 30 against the interior, through the base housing 2 and Cylinder head cover 4 is formed.

The camshafts 43 are supported in the area of the chain case 9 the two lower bracket halves 22, on the separate Single bearing block upper parts 44 are placed. These separate headstock upper parts 44 are wider (viewed in the axial direction) than the corresponding lower one Bearing block half 22 and take over the axial guidance of the camshaft. Thereby only needs a separate upper bearing part for the axial guidance per camshaft to be edited. Due to the separate top bracket parts at Assembly at the same time on the chain case side, depressing the Camshafts against the action of the valve springs, not shown. On the opposite end face 11 of the basic housing or in the corresponding bores of the cylinder head cover are mounting holes 45 introduced, on the one hand for machining the bearing holes and for others to depress the camshafts during assembly or create the necessary space.

Claims (15)

1. A cylinder-head arrangement of an internal-combustion engine,

   with a base housing (2) comprising gas-exchange ducts (7) and valve guides (6) and mounted on a cylinder block (1),

   with a barrel-tappet housing (3) mounted on the base housing (2),

   with a cylinder-head cover (4) covering the camshafts (43) mounted in two-part bearing stands (22, 37, 44),

   wherein the barrel-tappet housing (3) is arranged inside a space formed by the cylinder-head cover (4) and the base housing (2),

   characterized in that the barrel-tappet housing (3) is constructed in one piece,

   the lower bearing-stand halves (22) are integrated in the base housing (2),

   and the upper bearing-stand halves (37) are formed at least in part in the cylinder-head cover (4).
2. A cylinder-head arrangement according to Claim 1, characterized in that the upper bearing-stand halves (37) are integrally joined to the outer wall of the cylinder-head cover (4), and the lower bearing-stand halves (22) are integrally joined to the outer wall (10, 12) of the base housing (2).
3. A cylinder-head arrangement according to Claim 1 or 2, characterized in that the connexion face between the base housing (2) and the cylinder-head cover (4) is situated in one plane (T-T) with the separation face of the bearing-stand halves (22, 37).
4. A cylinder-head arrangement according to one of Claims 1 to 3, characterized in that the bolt connexion between the base housing (2) and the cylinder-head cover (4) is formed by the bolt connexion (23) of the bearing-stand halves (22, 37) at least in the region of the base block (8) contain[ing] the cylinder bores (5).
5. A cylinder-head arrangement according to one of Claims 1 to 4, characterized in that the bolt connexion between the base housing (2) and the cylinder block (1) is formed by four cylinder bolts (21) per cylinder which comprise the cylinder bore (5) in a rectangular arrangement in each case.
6. A cylinder-head arrangement according to Claim 5, characterized in that a bearing stand (22, 37) is arranged in each case between the adjacent cylinder bolts (21) of the juxtaposed cylinder bores (5).
7. A cylinder-head arrangement according to one of Claims 1 to 6, characterized in that a chain case (9), in the region of which the camshafts (43) are supported by one individual bearing stand (22, 44) in each case, is mounted on the front end of the cylinder-head arrangement.
8. A cylinder-head arrangement according to Claim 7, characterized in that the underside of the individual bearing stand is formed by a lower bearing-stand half (22) which is integrated in the base housing and on which a separate upper part (44) of the bearing stand is mounted.
9. A cylinder-head arrangement according to Claim 7 or 8, characterized in that the camshaft (43) is mounted axially by the individual bearing stand (22, 44).
10. A cylinder-head arrangement according to one of Claims 7 to 9, characterized in that a bore (45) in alignment with the camshaft (43) is formed on the front end (11) of the cylinder-head arrangement opposite the chain case (9).
11. A cylinder-head arrangement according to one of Claims 1 to 10, characterized in that oil ducts (17, 18, 19, 31, 33, 35) cast in the base housing (2) and the barrel-tappet housing (3) extend in the separation plane (T-T) between the said base housing (2) and the said barrel-tappet housing (4).
12. A cylinder-head arrangement according to Claim 11, characterized in that the barrel-tappet guides (28) are supplied with lubricating oil by way of the cast oil ducts.
13. A cylinder-head arrangement according to Claim 11 or 12, characterized in that the camshaft (43) is supplied with lubricating oil by way of the cast oil ducts in the separation plane (T-T) and by way of bored oil ducts to a bearing stand (22, 37).
14. A cylinder-head arrangement according to one of Claims 1 to 13, characterized in that the valve guides (6) and the barrel-tappet guides (28) have a bore (15) opening into the cylinder bore (5), the said bore (15) is extended and sealed by a sleeve (40) which is inserted between the barrel-tappet housing (3) and the cylinder-head cover (4).
15. A cylinder-head arrangement according to Claim 14, characterized in that the barrel-tappet housing (3) has an annular extension (31) which embraces the bore (15) and into which the sleeve (40) is inserted and is held securely and sealed by a sealing ring (41).

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