Cylinder head

Abstract

The present invention relates to a cylinder head (1) having at least one recess (23) for arranging at least one gas valve (20) and at least one spark plug (15), the spark plug (15) extending into a pre-chamber (17), the spark plug (15) being arranged along a spark plug rotation axis (16), the gas valve (20) being arranged along a gas valve rotation axis (19), the gas valve rotation axis (19) being inclined with respect to the spark plug rotation axis (16), and a distance (A) between the gas valve rotation axis (19) and the spark plug rotation axis (16) decreasing with increasing distance from the pre-chamber (17) in a direction opposite to the combustion chamber (2). An object of the present invention is to provide an improved cylinder head (1) that allows for improved arrangement and reduced installation space. In the present invention, this object is achieved by the aforementioned cylinder head (1) in that the recesses (23) of the spark plug (15) and the gas valve (20) are formed by one-off molding, preferably by casting, and particularly preferably have a surface (O) that is not subjected to mechanical post-machining.

Description

[Technical field]

[0001] The present invention relates to a cylinder head having at least one recess for arranging at least one gas valve and at least one spark plug, the spark plug reaching into a pre-chamber, the spark plug being arranged along a spark plug rotation axis and the gas valve being arranged along a gas valve rotation axis, the gas valve rotation axis being inclined with respect to the spark plug rotation axis, the distance between the gas valve rotation axis and the spark plug rotation axis decreasing with increasing distance from the pre-chamber in a direction opposite to the combustion chamber. [Background technology]

[0002] The cylinder head is intended for an internal combustion engine with gasoline engine combustion using the combustion of a gaseous fuel. Natural gas can be used as the fuel, for example. Any other gaseous fuel can also be burned. A cylinder head of this kind is known, for example, from CN 109098834. The cylinder head has a gas valve on one side of the cylinder axis and a spark plug arranged opposite the gas valve on the other side in the plane spanned by the cylinder axis. The gas valve is arranged parallel to the cylinder axis. The spark plug is therefore slightly inclined outwards away from the pre-chamber. The required installation space increases sharply from the pre-chamber. The gas exchange valves, whose guides are usually arranged around the periphery of the arrangement, have to be moved further outwards, so that the distance of the valve shafts to the cylinder axis becomes larger.

[0003] A similar arrangement is disclosed in AU 516619. In contrast to the aforementioned CN 109098834, the rotation axes of the gas valve and the spark plug are arranged parallel. In one of the two illustrated embodiments, the two machined surfaces overlap and lead into a common cavity. In the second illustrated embodiment, the machined surfaces are spaced apart from one another, which significantly increases the installation space required.

[0004] Although it is possible to save installation space by arranging the work surfaces so that they overlap one another, this reduces the quality of the surfaces that are obtained for accommodating further components, which leads to more rejects during production and therefore to increased production costs even with a reduced installation space. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] China Patent Application Publication No. 109098834 [Patent Document 2] Austrian Patent Application Publication No. 516619 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE PRESENT EMBODIMENT It is an object of the present invention to provide an improved cylinder head which allows for faster finishing. [Means for solving the problem]

[0007] According to the invention, this object is achieved by the aforementioned cylinder head in that the recesses for the spark plug and the gas valve are formed in one step - preferably by casting - and particularly preferably have surfaces which are not mechanically reworked.

[0008] As a result, most of the cavity in the cylinder head for receiving the ignition plug is formed by the primary molding, so that the subsequent processing can be carried out more quickly and easily.

[0009] The machined surfaces do not overlap, improving the quality of the obtained surfaces and reducing the manufacturing effort. The inclined arrangement reduces the distance away from the combustion chamber, saving installation space. The guides of the gas exchange valves can be arranged directly around the spark plug.

[0010] In the present invention, most of the recess is cast, and only the parts for inserting the spark plug and gas valve, the gas valve receiving surface and the spark plug receiving surface are machined. The two machined surfaces do not overlap each other. The embodiment according to the present invention has the advantage that it is possible to save installation space.

[0011] This effect can be particularly well exploited if the inclination angle between the gas valve rotation axis and the spark plug rotation axis is between 0.5 and 5 degrees, preferably 1.5 degrees.

[0012] A particularly advantageous position of the spark plug relative to the gaseous fuel introduced by the gas valve is obtained if the axis of rotation of the spark plug is arranged concentrically with respect to the axis of rotation of the cylinder in the cylinder bore, which allows the combustion to emanate as evenly as possible from the centrally located spark plug, which can have a significantly positive effect on the ignition characteristics.

[0013] This effect can be further enhanced if the pre-chamber rotation axis is arranged concentrically with respect to the cylinder rotation axis of the cylinder bore.

[0014] In addition, such a concentric arrangement of the components is advantageous in terms of the required installation space, and therefore the spread of the individual components in the lateral direction relative to the cylinder rotation axis can be reduced.

[0015] In order to make production even more efficient, it is preferred that the cylinder head has at least one receiving sleeve for the gas valve and the spark plug, in which recesses are formed.

[0016] The common recess for the gas valve and the spark plug is formed by casting in a separate component, which is called the receiving sleeve. It is preferred that the recess is not post-machined in any of the embodiments, which makes it possible to save manufacturing steps, production costs and production times.

[0017] In order to obtain a perfect, tight and sealed fixing of the spark plug, it is advantageous if, starting from the recess, the spark plug receiving surface is formed by a machined surface, preferably by a bore.

[0018] The same can be advantageously obtained for the gas valve if, starting from the recess, the gas valve receiving surface is formed by a machined surface, preferably by a bore.

[0019] To ensure the quality of the receiving surfaces, ease manufacturing, and minimize rejects, it is preferred that the spark plug receiving surface and the gas valve receiving surface be spaced apart, non-intersecting machined surfaces.

[0020] Furthermore, it is preferable that the machined surfaces for obtaining the gas valve receiving surface and the spark plug receiving surface do not penetrate the recesses, so that the machined surfaces do not have overlapping portions, thereby making it possible to reduce the intrusion of shavings into the receiving recesses of the other during machining.

[0021] It is expedient if a respective gas exchange valve is provided for gas exchange to the combustion chamber, and each gas exchange valve is equipped with a valve spring, so that the advantages of this arrangement in terms of the installation space saving can be fully utilized.

[0022] This effect is particularly evident in embodiments in which the receiving sleeve extends in the direction of the cylinder rotation axis up to and / or beyond the height at which the respective valve spring is located and the respective gas exchange valve is in the closed position.

[0023] Further savings in installation space are possible in comparison with conventional cylinder heads if the distance between the receiving sleeve and each gas exchange valve is small relative to the plane perpendicular to the cylinder rotation axis, the diameter-to-distance ratio being between 1.5 and 3.5.

[0024] The invention will now be further described with reference to the following non-limiting drawings, in which: [Brief description of the drawings]

[0025] [Figure 1] 1 is a cross-sectional view of a cylinder head according to the present invention; [Diagram 2] 2 is a cross-sectional view similar to FIG. 1 showing details of a receiving sleeve and a pre-chamber shell of a cylinder head according to the present invention. FIG. [Diagram 3] 3 is a further detail of the receiving sleeve and pre-chamber shell of FIG. 2; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] 1 shows a cross-section of a cylinder head 1 according to the invention. The surface of the combustion chamber 2 of the cylinder, not shown in detail, is called the fire cover 3. Leading into the combustion chamber 2 are gas exchange passages 4 which can be closed by respective gas exchange valves 5. Each gas exchange valve 5 is therefore displaceable in its respective guide 6 against the force of a valve spring 7.

[0027] In the cross-sectional view two gas exchange valves 5 are visible, each arranged on either side of the cylinder rotation axis 8 and configured as a respective poppet valve. Each valve spring 7 is supported by a first end 10 against a cover surface 9 of the cylinder head 1 in the direction of the cylinder rotation axis 8, away from the combustion chamber 2, in the embodiment shown. A second end 11, which is arranged around the gas exchange valve 5 facing away from the combustion chamber 2, is supported against the gas exchange valve 5.

[0028] Radially inward of the two gas exchange valves 5 from the cylinder rotation axis 8, the cylinder head 1 has a wall 12 with an opening 13 which passes through the cylinder head 1 along the cylinder rotation axis 8. Inside the opening 13, a receiving sleeve 14 is arranged. In the receiving sleeve 14, an ignition plug 15 is arranged along an ignition plug rotation axis 16. Adjacent to the spark plug 15 in the direction of the combustion chamber 2, a prechamber 17 is provided, which is at least partially surrounded by a prechamber shell 18. The prechamber 17 is connected to the combustion chamber 2 via respective overflow openings, which are not shown in detail. The prechamber 17 has a prechamber rotation axis 27 along which the prechamber is arranged.

[0029] In the illustrated embodiment, the pre-chamber axis of rotation 27 of the pre-chamber 17 and the spark plug axis of rotation 16 of the spark plug 15 are arranged concentrically with respect to the cylinder axis of rotation 8 of the cylinder bore, not shown in detail.

[0030] In the alternative embodiments, the opening 13 is arranged displaced with respect to the cylinder rotation axis 8. Furthermore, the pre-chamber rotation axis 27 and the spark plug rotation axis 16 can be spaced apart from each other with respect to the cylinder rotation axis 8.

[0031] The outer diameter D of the receiving sleeve 14 reaches very close to each valve spring 7. The distance between the receiving sleeve 14 and the gas exchange valve 5 corresponds to approximately 0.4 times the outer diameter D. The relationship between the diameter D and the distance E, expressed here as the ratio D / E, is approximately 2.4. In typical embodiments, the ratio D / E can be between 1.5 and 3.5.

[0032] The distance E is given in the plane ε, which is perpendicular to the cylinder rotation axis 8 and therefore forms the normal axis of the cylinder rotation axis 8 .

[0033] The intersection of the gas valve rotation axis 19 and the spark plug rotation axis 16 is arranged outside the receiving sleeve 14 in the direction from the combustion chamber 2 towards the cover surface 9 .

[0034] Around the receiving sleeve 14 and the prechamber shell 18 there are arranged cooling chambers and cooling channels, indicated by the reference characters K. Around the gas exchange channels 4 there are also cooling chambers K for cooling the cylinder head 1. Seals are provided to protect the individual working fluids from each other.

[0035] A gas valve 20 is arranged along the gas valve rotation axis 19. The gas valve 20 leads to a gas passage 21, which itself fluidly connects the gas valve 20 to the pre-chamber 17.

[0036] The receiving sleeve 14 extends from the fire shield 3 over a height H, at which the first end 10 of the valve spring 7 rests on the support surface 22. In the embodiment shown, the receiving sleeve 14 reaches within the opening 13 almost up to the cover surface 9.

[0037] The receiving sleeve 14, the elements therein as well as the pre-chamber shell 18 are shown enlarged in FIG. 2. It can be seen that the gas valve axis of rotation 19 is inclined relative to the spark plug axis of rotation 16. The inclination angle φ in the illustrated embodiment is about 1.5°. In alternative embodiments the inclination angle φ is between 0.5° and 5°. The gas valve 20 is inclined relative to the spark plug 15 in the direction of the cover surface 9 of the cylinder head 1.

[0038] Here, the spark plug 15 is arranged concentrically with respect to the cylinder rotation axis 8 of the cylinder bore and the pre-chamber 17 .

[0039] The gas valve 20 is particularly small and has a very small distance A to the spark plug 15. The installation space is further reduced by the inclination at the inclination angle φ, which further reduces the distance A to the cover surface 9 of the cylinder head 1.

[0040] The receiving sleeve 14 has therein a recess 23. The recess 23 is formed by casting the receiving sleeve 14 for both the gas valve 20 and the spark plug 15. The surface O of the recess 23 is not machined.

[0041] Both the gas valve 20 and the spark plug 15 lead from the combustion chamber 2 into the recess 23 .

[0042] A gas valve receiving surface 24 is provided for receiving and fixing the gas valve 20 in the receiving sleeve 14. The gas valve receiving surface 24 is formed by machining along a machining surface 25 for the gas valve 20.

[0043] There is likewise a spark plug receiving surface 26 for receiving and fixing the spark plug 15 in the receiving sleeve 14. The spark plug receiving surface 26 is also formed by machining along the second machining surface 25 for the spark plug 15.

[0044] The gas valve receiving surface 24 and the spark plug receiving surface 26 are, for example, cylindrical in shape.

[0045] In the illustrated embodiment, a spark plug 15 and a gas valve 20 are disposed within each bore.

[0046] The pre-chamber shell 18 is preferably coupled to the receiving sleeve 14 via connections not shown in detail.

[0047] The respective machined surfaces 25 for the gas valve 20 and the spark plug 15 are indicated by dashed lines in FIGS.

[0048] The working surfaces 25 do not overlap within the receiving sleeve 14 and always have a distance from one another within the receiving sleeve 14 .

[0049] 3, there is shown in greater detail the receiving sleeve 14 and pre-chamber shell 18 of FIG.

Claims

1. 1. A cylinder head (1) having at least one recess (23) for arranging at least one gas valve (20) and at least one spark plug (15), the spark plug (15) reaching into a pre-chamber (17), the spark plug (15) being arranged along a spark plug rotation axis (16), the gas valve (20) being arranged along a gas valve rotation axis (19), the gas valve rotation axis (19) being inclined with respect to the spark plug rotation axis (16), a distance (A) between the gas valve rotation axis (19) and the spark plug rotation axis (16) decreasing with increasing distance from the pre-chamber (17) in a direction opposite to the combustion chamber (2), characterized in that the recesses (23) for the spark plug (15) and the gas valve (20) are formed by casting and have a surface (O) that is not mechanically post-machined.

2. 2. The cylinder head (1) according to claim 1, characterized in that the inclination angle (φ) between the gas valve rotation axis (19) and the spark plug rotation axis (16) is between 0.5 degrees and 5 degrees.

3. A cylinder head (1) as described in claim 2, characterized in that the inclination angle (φ) between the gas valve rotary shaft (19) and the ignition plug rotary shaft (16) is 1.5 degrees.

4. 4. The cylinder head (1) according to claim 1, wherein the spark plug rotation axis (16) is arranged concentrically with a cylinder rotation axis (8) of the cylinder bore.

5. 5. Cylinder head (1) according to any one of claims 1 to 4, characterized in that the pre-chamber rotation axis (27) is arranged concentrically with the cylinder rotation axis (8) of the cylinder bore.

6. 6. A cylinder head (1) according to claim 1, characterized in that it has at least one receiving sleeve (14) for a gas valve (20) and for an ignition plug (15), in which the recess (23) is formed.

7. 7. A cylinder head (1) according to any one of claims 1 to 6, characterized in that an ignition plug receiving surface (26) is formed by a surface machined starting from the recess (23).

8. A cylinder head (1) as described in claim 7, characterized in that the spark plug receiving surface (26) is formed by a bore.

9. 9. A cylinder head (1) according to any one of the preceding claims, characterized in that a gas valve receiving surface (24) is formed by a bore starting from the recess (23).

10. 10. A cylinder head (1) according to any one of claims 7 to 9, characterized in that the spark plug receiving surface (26) and the gas valve receiving surface (24) are non-intersecting machined surfaces spaced apart from one another.

11. 11. The cylinder head (1) according to claim 7, wherein a machined surface (25) for obtaining a gas valve receiving surface (24) and an ignition plug receiving surface (26) does not penetrate into the recess (23), so that the machined surface (25) has no overlapping portions.

12. 12. A cylinder head (1) according to any one of claims 1 to 11, characterized in that gas exchange valves (5) are provided for gas exchange into the combustion chamber (2), each of the gas exchange valves (5) being equipped with a valve spring (7).

13. 13. The cylinder head (1) according to claim 12, characterized in that the receiving sleeve (14) extends in the direction of the cylinder rotation axis (8) up to and / or beyond a height (H) at which the valve spring (7) is located and the gas exchange valve (5) is in the closed position.

14. 14. The cylinder head (1) according to claim 12 or 13, characterized in that the distance (E) between the receiving sleeve (14) and the gas exchange valve (5) is small relative to a plane (ε) perpendicular to the cylinder rotation axis (8) and the ratio (D / E) of the diameter (D) to the distance (E) is between 1.5 and 3.5.

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