DE102016015289A1 - Method for producing a cylinder head and cylinder head - Google Patents

Abstract

The invention relates to a method for producing a cylinder head (10). In this case, a casting of a cylinder head base body (12) takes place, in which cooling passages (24, 24) circulating around the valve seat regions (20, 50) at least partially in the circumferential direction (22, 52) at different valve seat regions (20, 50) of the cylinder head base body (12) , 54) and thereby in each case by means of at least one, from a radially outer wall (26, 56) of the respective cooling channel (24, 54) away and up to a respective valve seat opening (28, 58) out towards extending bar member (32, 34, 62, 64) are closed. Subsequently, the cylinder head (10) is produced from the cylinder head main body (12) by opening the respective cooling channels (24, 54) and removing at least one web portion (36, 38, 66, 68) of the respective, at least one web element (32 , 34, 62, 64) and thereby producing respective respective flow-through openings (40, 42, 70, 72) which release the respective cooling channels (24, 54) for throughflow with coolant.

Description

The invention relates to a method for producing a cylinder head for an internal combustion engine. Another aspect of the invention relates to a cylinder head for an internal combustion engine.

In the manufacture of internal combustion engines, respective cylinder heads of the internal combustion engines are often produced by a casting process. Such casting methods enable a particularly high production rate with simultaneously low production costs.

From the DE 1 576 727 A1 is a cast cylinder head for liquid-cooled, valve-controlled internal combustion engines with pressed valve seat rings known. The valve seat rings limit respective cooling channels of the internal combustion engine, whereby the valve seat rings outside have direct contact with a cooling liquid flowing through the cooling channels.

The DE 32 05 676 A1 discloses a cooled valve seat for intake valves and exhaust valves of internal combustion engines. A valve seat ring provided here has cavities through which coolant can flow, wherein the valve seat is formed by a valve seat ring which can be inserted into a recess at the mouth of the inlet channel or outlet channel in the cylinder head. The valve seat encloses an annular flow channel together with the recess.

Object of the present invention is to provide a method and a cylinder head of the type mentioned, which allow a needs-based and easily predetermined flow of cooling channels with coolant.

This object is achieved by a method having the features of patent claim 1 and by a cylinder head having the features of patent claim 4. Advantageous developments of the present invention are the subject of the dependent claims.

• - Gießen eines Zylinderkopfgrundkörpers, bei welchem an verschiedenen Ventilsitzbereichen des Zylinderkopfgrundkörpers, jeweilige, zumindest bereichsweise in Umfangsrichtung um die Ventilsitzbereiche umlaufende Kühlkanäle, zum Führen von Kühlmittel, hergestellt und dabei mittels jeweils wenigstens eines, sich von einer radial äußeren Wandung des jeweiligen Kühlkanals weg und bis zu einer jeweiligen Ventilsitzöffnung, zur Aufnahme eines jeweiligen Ventilsitzringes, hin erstreckenden Stegelements verschlossen werden;
• - Herstellen des Zylinderkopfes aus dem Zylinderkopfgrundkörper durch Öffnen der jeweiligen Kühlkanäle, indem ein Entfernen zumindest eines Stegbereichs des jeweiligen, wenigstens einen Stegelements und dadurch ein Herstellen jeweiliger, die jeweiligen Kühlkanäle für eine Durchströmung mit Kühlmittel freigebende, jeweilige Durchströmöffnung erfolgt.

An inventive method for producing a cylinder head for an internal combustion engine comprises at least the following steps:

• Casting a cylinder head main body, in which at different valve seat areas of the cylinder head body, respective, at least partially circumferentially around the valve seat areas encircling cooling channels, for guiding coolant, and thereby by means of at least one, away from a radially outer wall of the respective cooling channel and until be closed to a respective valve seat opening, for receiving a respective valve seat ring, extending stub element;
• - Manufacture of the cylinder head from the cylinder head body by opening the respective cooling channels, by removing at least one web portion of the respective, at least one web element and thereby producing respective, the respective cooling channels for a flow of coolant releasing, respective flow opening takes place.

The respective web elements, which initially close the respective cooling channels, can be provided with the defined and particularly precisely producible throughflow opening when the respective web regions are removed. The respective flow-through openings can be produced, for example, by machining and thus material-removing machining, in which the web areas can be removed from the respective web elements, for example in the circumferential direction.

The invention is based on the finding that the production of the cylinder head body can be done particularly cost-effectively and quickly by casting, but in casting generally increased manufacturing tolerances, for example, by the occurrence of material shrinkage, can occur. As a result, the cooling channels after casting of the cylinder head body may each have different cooling channel diameter. By opening the respective cooling channels (by removing the respective web regions with simultaneous production of the respective flow-through openings), the through-flow openings can be produced with a particularly exact opening cross section, so that a defined throttle point can be provided in the cooling channel, so to speak. By making the flow openings thus needs-based and easily predetermined flow through the cooling channels with coolant is possible.

In an advantageous development of the invention, during the casting of the cylinder head main body at the respective valve seat areas in each case at least two web elements closing the respective cooling channel and mutually offset in the circumferential direction are produced. This is advantageous because by the production of the web elements offset in the circumferential direction, respective alignment possibilities or investment possibilities are created which can facilitate the insertion of the valve seat rings. As a result, installation of the valve seat rings in the respective valve seat openings can thus be simplified. Another advantage is that on the at least two web elements also Respective, mutually different web portions can be removed, whereby each of the two web elements each flow openings can be made with mutually different opening cross-section. As a result, different throttle points (in the form of the respective flow-through openings) can be created in a particularly simple manner, and thus different flow velocities of the coolant flowing through the respective cooling channels can also be set at the respective, at least two web elements. This allows the production of cooling channels with locally varying and thus demand-specified heat transfer conditions.

Another aspect of the invention relates to a cylinder head for an internal combustion engine, which is obtainable by a method according to the invention. Advantageous embodiments and preferred embodiments of the method according to the invention are also to be regarded as advantageous embodiments and preferred embodiments of the cylinder head according to the invention and vice versa.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

• 1 eine Schnittdarstellung eines Teilbereichs eines Zylinderkopfgrundkörpers; und
• 2 eine Schnittdarstellung eines Teilbereichs eines Zylinderkopfes.

Showing:

• 1 a sectional view of a portion of a cylinder head body; and
• 2 a sectional view of a portion of a cylinder head.

1 shows a cylinder head body 12 one in 2 partially shown cylinder head 10 , The cylinder head 10 is made by the cylinder head body 12 is first cast as part of a casting process. In the casting process are at different valve seat areas 20 . 50 of the cylinder head body 12 , respective, at least partially in the circumferential direction 22 , 52 around the valve seating areas 20 . 50 circulating cooling channels 24 . 54 made to carry coolant. The valve seat area 20 For example, it may be provided for an intake valve of the internal combustion engine and the valve seat region 50 for example, for an exhaust valve of the internal combustion engine. However, it is clear that both valve seat areas 20 . 50 For example, for each one exhaust valve can be provided.

When manufacturing the cylinder head body 12 by the casting are at the respective valve seat areas 20 . 50 in each case at least two, the respective cooling channel 24, 54 occlusive, and to each other in the respective circumferential direction 22 . 52 staggered web elements 32 . 34 . 62 . 64 produced. The respective web elements extend from a radially outer wall 26 . 56 of the respective cooling channel 24 , 54 away and up to a respective valve seat opening 28 . 58 for receiving a respective valve seat ring 30 . 60 ,

To get out of the cylinder head body 12 the cylinder head 10 manufacture, the respective cooling channels 24 . 54 opened by a respective removal of at least one land area 36 . 38 . 66 . 68 of the respective, at least one stake element 32 . 34 . 62 , 64 and thereby producing respective ones, the respective cooling channels 24 . 54 for a flow with coolant releasing, respective flow opening 40 . 42 . 70 . 72 he follows.

To within the respective cooling channels 24 . 54 locally different flow velocities of the coolant and thus to allow locally different heat transfer, at least two of the respective flow openings 40 . 42 . 70 . 72 be made with different opening cross-sections.

2 shows a detail of the respective valve seat rings 30 . 60 , which in the respective valve seat openings 28 . 58 are used. The respective valve seat rings 30 . 60 limit the respective cooling channels 24 . 54 at least in certain areas, so that the respective cooling channels 24 . 54 flowing coolant in direct contact with the respective valve seat rings 30 . 60 can occur, whereby a particularly effective cooling of the valve seat rings 30 . 60 is possible.

The present invention enables a particularly uniform and needs-based cooling of the respective valve seat rings 30 . 60 which are received in the respective valve seat openings 28, 58. By making the flow openings 40 . 42 . 70 . 72 can respective opening cross-sections, or Durströmungsquerschnitte the respective cooling channels 24 . 54 Specifically specified and thus each defined throttle points are created. This can be achieved that the respective valve seat rings 30 . 60 at the respective valve seat areas 20 . 50 For example, each be uniformly and with the best possible cooling and high flow velocity of the coolant to be washed directly. This can be advantageously contributed to that at Internal combustion engines with cylinder heads produced in this way 10 Overall, the lowest possible component temperatures, especially in the valve seat rings 30 . 60 be achieved. This contributes to generally lower combustion chamber temperatures and thus reduced nitrogen oxide emissions, reduced tendency to knock and reduced wear in internal combustion engines. By reducing the component temperature can be used on cheaper materials.

Furthermore, the present invention enables a cost effective, efficient, uniform and over all cylinders as well as all valve seat areas 20 . 50 Evenly distributed, precise and suitable for mass production cooling.

The cylinder head 10 is largely by casting the cylinder head body 12 manufactured, ie the cylinder head body 12 can be pre-cast and thus manufactured inexpensively. The removal of the respective web areas 36 . 38 . 66 , 68 and the concomitant production of the respective flow openings 40 . 42 , 70, 72 requires only a minor mechanical processing. As a result, a total of one production of the cylinder head 10 at low cost and with low chip formation, while at the same time precisely distributing the flow rate of the coolant to the respective cooling channels 24 . 54 and thus on all cylinders possible.

The present invention also makes it possible to reduce the thermal load, for example, of exhaust valves, exhaust valve seat rings and cylinder head materials in the region of respective combustion chambers of the internal combustion engine with particularly little effort. Furthermore, the invention enables a reduction in the combustion chamber temperatures and, associated therewith, a reduction in the tendency to knock, thereby enabling operation of the internal combustion engine with generally increased performance and lower consumption.

In the context of the invention, the respective cooling channels 24 . 54 as well as the respective web elements 32 . 34 . 62 . 64 are first precast, with the respective web elements 32 . 34 . 62 . 64 each web can represent with minimal cast wall thickness. These webs can, for example, with a cutter to a desired flow cross-section by removing the respective web portions 36 . 38 . 66 . 68 be edited while the respective flow openings 40 . 42 . 70 . 72 be provided. As the bridge elements 32 . 34 . 62 . 64 only over a small portion in the respective circumferential direction 22 . 52 can extend along the respective cooling channels 24, 54, an overall short processing time (for example, a short milling time) is given at the same time low chip formation and the possibility of producing a defined flow cross-section.

Overall, different flow cross sections can be set for different cylinders or exhaust valve seat rings, so that a particularly needs-based cooling can be achieved. The presented method can be used for all valve seat areas of the cylinder head main body 12 are applied, although in the present case and only the processing based on the two valve seat portions 20, 50 has been explained. By means of the presented method, for example, a pressure or a flow velocity of the coolant can be set slightly lower than at the first cylinder or first valve in the direction of flow at a cylinder of the internal combustion engine which is the rearmost in the flow direction of the coolant. For this purpose, for example, on the last cylinder, the flow cross-section, that is, at least some of the respective flow openings 40 . 42 . 70 . 72 greater than on the first cylinder.

LIST OF REFERENCE NUMBERS

10

cylinder head

12

Cylinder head body

20

Valve seat area

22

circumferentially

24

cooling channel

26

transformation

28

Valve seat opening

30

Valve seat ring

32

web element

34

web element

36

web region

38

web region

40

flow-through

42

flow-through

50

Valve seat area

52

circumferentially

54

cooling channel

56

wall

58

Valve seat opening

60

Valve seat ring

62

web element

64

web element

66

web region

68

web region

70

flow-through

72

flow-through

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 1576727 A1 [0003]
• DE 3205676 A1 [0004]

Claims (4)

Method for producing a cylinder head (10) for an internal combustion engine, comprising at least the following steps: Casting of a cylinder head base body (12), in which cooling ducts (24, 54) circulating around the valve seat areas (20, 50) at least partially in the circumferential direction (22, 52) at different valve seat regions (20, 50) of the cylinder head base body (12) for guiding coolant, manufactured and thereby by means of at least one each, from a radially outer wall (26, 56) of the respective cooling channel (24, 54) away and to a respective valve seat opening (28, 58), for receiving a respective Valve seat ring (30, 60), towards the extending web element (32, 34, 62, 64) are closed; - producing the cylinder head (10) from the cylinder head body (12) by opening the respective cooling channels (24, 54) by removing at least one web portion (36, 38, 66, 68) of the respective, at least one web element (32, 34, 62, 64) and thereby producing respective respective flow-through openings (40, 42, 70, 72) which release the respective cooling channels (24, 54) for throughflow with coolant. Method according to Claim 1 , characterized in that during the casting of the cylinder head main body (12) at the respective valve seat areas (20, 50) at least two, the respective cooling channel (24, 54) closing, and mutually in the circumferential direction (22, 52) offset web elements (32, 34 , 62, 64). Method according to Claim 1 or 2 , characterized in that at least two of the flow-through openings (40, 42, 70, 72) are produced with mutually different opening cross-sections. Cylinder head (10) for an internal combustion engine, obtainable by a method according to one of Claims 1 to 3 ,

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