CN104373241A - Cylinder head of a combustion engine and method for constructing a cylinder head of a combustion engine - Google Patents

Abstract

The invention relates to a cylinder head of an internal combustion engine and a method for manufacturing a cylinder head of an internal combustion engine, in particular to a cylinder head of an internal combustion engine with at least one discharge channel (4) passing through a sheet metal casing ( 1) Forming, casting the cylinder head around the sheet metal casing (1). According to the invention it is provided that all exhaust ducts ( 4 ) and exhaust manifolds ( 5 ) are formed by the sheet metal housing ( 1 ) which is cast in the cylinder head. Furthermore, the invention relates to a method for producing a cylinder head of an internal combustion engine, in which method the one-piece sheet metal housing (1) or the individual housing parts (2, 3) of the sheet metal housing are initially at least partially zoned Sectionally provided with a cladding (8) and/or a certain structure, then inserted into a casting mold and finally made of casting material to surround a one-piece sheet metal casing (1) or individual casing parts (2) of a sheet metal casing ,3) The cylinder head is formed by casting.

Description

Cylinder head of an internal combustion engine and method for producing a cylinder head of an internal combustion engine

technical field

The invention relates to a cylinder head of an internal combustion engine with at least one discharge channel formed by a sheet metal casing around which the cylinder head is cast.

Furthermore, the invention relates to a method for producing a cylinder head of an internal combustion engine, in which method a single-piece sheet metal housing or individual housing parts of the sheet metal housing are integrated into the cylinder head.

Background technique

A device of the above-mentioned type is known from the publication DE 33 15 988 A1. This publication describes a cylinder head of an internal combustion engine with at least one discharge channel formed by a sheet metal casing cast into the cylinder head. An insulating layer is provided between the cast-in sheet metal casing and the cast body of the cylinder head. This thermally insulating layer can be formed by applying a ceramic material (for example by spraying) to the sheet metal casing before casting.

A method of the above-mentioned type is known from publication DD 290 705 A5. This publication describes a ceramic lining for gas-conducting channels of a cylinder head of an internal combustion engine. The ceramic lining brings about good thermal insulation of the exhaust gas flowing through the exhaust pipe. The liner is produced by being additionally inserted into the already cast cylinder head. The liner is fastened to the cast material of the cylinder head by means of a high temperature stable adhesive.

Furthermore, the use of preceramic polymers is known from publications DE 10 2009 046 003 A1 and DE 10 2007 034 609 A1 and DE 10 2006 008 010 A1. The pre-ceramic polymer is applied to the workpiece and converted to an amorphous or crystalline ceramic by heating.

An exhaust manifold is a component of the exhaust system of an internal combustion engine. Usually the exhaust manifold is connected directly to the engine, in particular to the cylinder head of the engine. The exhaust manifold acts as a header and unites the individual exhaust passages of the engine's combustion chambers into a common exhaust pipe. The intensive cooling required by the cylinder head when the exhaust manifold is integrated in the cylinder head also acts on the exhaust ducts and in particular on the exhaust manifold. Since the exhaust gas remains longer in the cylinder head when the exhaust manifold is integrated in the cylinder head, the exhaust gas is correspondingly cooled. However, high exhaust gas temperatures are advantageous for the operation of catalytic converters and/or turbochargers arranged in the exhaust line between the exhaust manifold and the exhaust system.

Contents of the invention

Against this background, the object of the present invention is to overcome the disadvantages of the prior art and to improve devices and methods of the type mentioned at the outset.

This object is solved with an arrangement according to the features of claim 1 . The dependent claims relate to particularly advantageous developments of the invention.

According to the invention, therefore, a cylinder head of an internal combustion engine is provided for which all exhaust ducts are formed at least in sections and the exhaust manifold is formed by a sheet metal casing around which the cylinder head is cast. . This makes it possible to create the exhaust gas channel formed by the exhaust gas channel and the exhaust manifold using a material that has a low thermal conductivity and is highly stable against aggressive exhaust gas.

In one embodiment of the invention, the sheet metal casing is designed such that all outlet channels are completely lined, in particular from the valve seat to the exhaust manifold, with the sheet metal casing. In an alternative, simpler and therefore preferred embodiment in terms of production technology, the sheet metal casing extends from the exhaust manifold only over a partial length section of the exhaust duct. For example, the sheet metal casing extends from the exhaust manifold only to the beginning of the sharp bend in the middle section of the exhaust duct, so that the sheet metal casing has an approximately flat geometry in its entirety.

It has proven to be advantageous if the sheet metal housing is designed in one piece. On the one hand, this enables rapid and precise loading of the casting mold, and on the other hand, the geometry of the exhaust duct can be precisely predetermined by the sheet metal housing and can be individualized independently of the casting mold. Furthermore, the one-piece sheet metal housing has only a small number of joining areas and connection interfaces, which reduces the outlay for producing the guide channel which is sealed against exhaust gas.

It has proven practical to fill the sheet metal casing with sand cores, which are only removed after casting. The processing of thin-walled and therefore sensitive sheet metal housings is thus simpler and more reliable.

However, it can also be advantageous if the sheet metal housing is assembled from a plurality of housing parts, preferably from two housing parts. This facilitates the handling of the sheet metal casing, in particular during its manufacture, during transport, storage and during further processing (for example insertion into a casting mould). Sheet metal housings can easily deform due to their small wall thickness and thus become unusable.

Casting molds usually consist of two mold halves. Since the two mold halves are also prepared independently of each other for casting, it is advantageous if one housing part is the upper half-shell of the sheet-metal housing and the other housing part is the lower half-shell of the sheet-metal housing. Each half shell is associated with the other half of the cross-section of the exhaust duct or exhaust manifold. Before the casting mold is closed, the half shells are inserted into the corresponding mold halves.

In particular, it is desirable that the sheet metal housing be oriented partially perpendicularly to the envelope curve of the exhaust duct and/or the exhaust manifold in the joint region of two adjacent housing parts. In the case of a multi-part sheet metal housing, it is thus possible to achieve a high degree of tightness against the exhaust gas. The edge sections of the two housing parts, which are oriented perpendicular to the envelope curve, bear against each other and are connected non-positively and/or materially when cast around. This is not possible for the exhaust gas, which flows behind the sheet metal casing, in particular squeezed between the sheet metal casing and the cylinder head. This serves to protect the cylinder head and also the insulating layer which may be provided between the sheet metal casing and the cylinder head.

It has been found that it is very possible for the sheet metal housing to have a coating at least in sections on the outer side facing the cylinder head and/or on the inner side facing the exhaust duct. The coating is formed from a ceramic material and/or from an enamelled material and/or from a pre-ceramic polymer, the coating being applied to the sheet metal housing before the cylinder head is cast. Applying the coating is preferably carried out by means of thermal application, spraying and/or dipping. Multiple layers of different materials are possible here. Zirconia and aluminum oxide have proven to be particularly useful as ceramic materials.

The exhaust passage is a passage structure between the combustion chamber and the exhaust pipe coupled at the cylinder head that contains the exhaust passage and the exhaust manifold and guides the exhaust gas.

The heat transfer between the sheet metal housing and the cylinder head made of aluminum is greater than in the case of interposed cladding and/or a certain structure of the sheet metal housing. A cladding or a certain structure applied on the outside of the sheet metal housing is protected against exhaust gases. The coating has a thickness of 0.1 to 10 mm, preferably 0.5 mm. The sheet metal casing has a thickness of 0.1 to 10 mm, preferably 0.5 mm. According to a particular embodiment, the sheet metal casing and the cladding have the same thickness.

According to the invention, thermal insulation of the sheet metal housing relative to the cylinder head is also achieved in that the sheet metal housing is structured at least in sections on the outer face facing the cylinder head. The defined structure can be formed by application and/or recesses on the outside. An insulating gap is provided between the sheet metal housing and the cylinder head by this definition.

Furthermore, the thermal isolation of the exhaust gas from the cylinder head can reduce the thermal load on the cylinder head and thus reduce the need for cooling.

This object is also solved with a method according to the features of claim 9 . The dependent claims relate to expedient developments of the invention.

According to the invention, therefore, a method for producing a cylinder head of an internal combustion engine is provided, in which method the individual housing parts of a single-part sheet metal housing or a multi-part sheet metal housing are first provided at least in sections cladding and/or certain structures. The single-piece sheet metal casing or the individual casing parts of the multi-part sheet metal casing are then inserted into the casting mold and the casting mold is closed. Finally, the cylinder head is formed from the casting material by casting around the sheet metal casing. The sheet metal casing is coated by means of a thermal application process such as flame spraying and/or spraying and/or dipping. A certain structure of the sheet metal casing is achieved by means of sandblasting and/or by means of a chemical reaction and/or by means of a laser beam.

In the case of a pre-ceramic polymer as coating, the pre-ceramic polymer transforms into a ceramic material above a certain temperature. This transformation only takes place during casting or during operation of the internal combustion engine.

Description of drawings

The invention allows many implementation forms. In order to further explain the basic principle, one of a number of embodiments is shown in the drawing and is described below, wherein:

Figure 1 shows a schematic illustration of the sheet metal casing of the exhaust channel;

FIG. 2 shows a schematic sectional view of a section of a cylinder head.

reference chart

1 sheet metal enclosure

2 Housing parts

3 Housing parts

4 discharge channels

5 exhaust manifold

6 outside

7 inside

8 cladding

9 Exhaust channel

10 cylinder head

11 seam area

12 edge segment

13 thickness.

Detailed ways

FIG. 1 shows a two-part sheet metal enclosure 1 . The sheet metal housing 1 comprises two housing parts 2, 3, of which one housing part 2 is the upper half of the sheet metal housing 1 and the other housing part 3 is the lower half of the sheet metal housing 1, The housing parts 2 , 3 are assembled together to form the sheet metal housing 1 . The exhaust duct 9 , comprising the exhaust duct 4 and the exhaust manifold 5 , is formed by the sheet metal housing 1 , which has an outer face 6 and an inner face 7 . The sheet metal housing 1 has a cladding 8 on the outside 6 .

FIG. 2 shows a section of a cylinder head 10 with at least one outlet duct 4 of an internal combustion engine not further described here. The exhaust duct 9 , which includes all exhaust ducts 4 and the exhaust manifold 5 of the internal combustion engine, which is sketched in FIG. 1 , is formed by a sheet metal casing 1 cast into the cylinder head 10 . The sheet metal housing 1 is assembled from two housing parts 2 , 3 . The sheet metal shell 1 has an edge section 12 in the seam region 11 . The edge section 12 is partially oriented perpendicular to the envelope curve of the exhaust gas channel 9 . Edge sections 12 of adjacent housing parts 2 , 3 bear against each other. The sheet metal housing 1 has a coating 8 in sections on its outer face 6 facing the cylinder head 10 . The thickness 13 of the cladding 8 and the sheet metal casing 1 is each 0.5 mm.

Claims (10)

1. A cylinder head (10) of an internal combustion engine with at least one discharge channel (4) formed by a sheet metal casing (1) around which the sheet metal casing (1) is cast The cylinder head (10) is characterized in that all the discharge channels (4) are at least partially sectioned and the exhaust manifold (5) passes through a sheet metal casing which is cast in the cylinder head (10) (1) Formation. 2. The cylinder head (10) according to claim 1, characterized in that the sheet metal casing (1) is embodied in one piece. 3. Cylinder head (10) according to claim 1, characterized in that the sheet metal housing (1) consists of a plurality of housing parts (2, 3), preferably of two housing parts (2 ,3) Assembled. 4. The cylinder head (10) according to claim 3, characterized in that one housing part (2) is the upper half shell of a sheet metal housing (1) and the other housing part (3) is a metal The lower half-shells of the plate casing (1), wherein each half-shell is associated with the other half of the cross-section of the discharge channel (4) or exhaust manifold (5). 5. Cylinder head (10) according to at least one of claims 3 and 4, characterized in that the sheet metal casing (1) is at the joint of two adjacent casing parts (2, 3) Sections of the region ( 11 ) are oriented perpendicularly to the envelope curve of the exhaust duct ( 4 ) or the exhaust manifold ( 5 ). 6. The cylinder head (10) according to at least one of the preceding claims, characterized in that the sheet metal casing (1) is at least partially sectioned on the outside facing the cylinder head (10) ( 6) and/or at the inner face (7) facing the exhaust channel (9) including said exhaust channel (4) and said exhaust manifold (5) with a cladding (8), wherein The coating ( 8 ) is formed before the cylinder head ( 10 ) is cast with a ceramic material and/or with an enameled material and/or with a pre-ceramized polymer. 7. The cylinder head (10) according to claim 6, characterized in that the cladding (8) has a thickness (13) of 0.1 to 10 mm, preferably 0.5 mm, and/or the The sheet metal casing (1) has a thickness (13) of 0.1 to 10 mm, preferably 0.5 mm. 8. The cylinder head (10) according to at least one of the preceding claims, characterized in that the sheet metal casing (1) is at least partially sectioned on the outside facing the cylinder head (10) ( 6) has a certain structure. 9. A method for manufacturing a cylinder head (10) of an internal combustion engine, in which method a one-piece sheet metal casing (1) or individual casing parts (2,3) of a sheet metal casing (1) First, at least in sections, the cladding ( 8 ) is provided and/or provided with a structure, then inserted into the casting mold and finally the casting material is used to surround the one-piece sheet metal casing ( 1 ) or the individual sheets of the sheet metal casing The cylinder head (10) is formed by casting the casing parts (2,3). 10. The method according to claim 9, characterized in that the coating (8) is applied by means of thermal application methods such as flame spraying and/or by means of sandblasting and/or by means of chemical reactions and/or by means of The defined structure is generated by a laser beam.