Cylinder head

Abstract

A cylinder head comprising at least one pre-chamber, at least one spark plug projecting into the pre-chamber, and at least one pre-chamber gas valve opening into the pre-chamber, wherein the spark plug and the pre-chamber gas valve are arranged in a common cavity of the cylinder head, wherein the spark plug and the pre-chamber gas valve are arranged in bores which mutually pass through each other.

Claims

1. A cylinder head comprising: at least one pre-chamber; at least one spark plug projecting into the at least one pre-chamber; and at least one pre-chamber gas valve opening into the at least one pre-chamber; wherein the at least one spark plug and the at least one pre-chamber gas valve are each arranged in a common cavity of the cylinder head, and wherein the at least one pre-chamber gas valve is arranged in a longitudinally extending valve bore defined by a first circumference and the at least one spark plug is arranged in a longitudinally extending plug bore defined by a second circumference parallel with respect to the longitudinally extending valve bore, with the valve bore first circumference and the plug bore second circumference mutually intersecting and overlapping each other.

2. The cylinder head of claim 1, wherein the at least one spark plug is arranged in a spark plug sleeve, and the common cavity is arranged in the spark plug sleeve.

3. The cylinder head of claim 1, wherein sealing of the at least one pre-chamber gas valve relative to the cylinder head or the spark plug sleeve is effected over a periphery of the at least one pre-chamber gas valve.

4. The cylinder head of claim 3, wherein sealing of the at least one pre-chamber gas valve is through use of at least one O-ring.

5. The cylinder head of claim 4, wherein the at least one O-ring is arranged in an opening formed by projections at an outside wall of the at least one pre-chamber gas valve.

6. An internal combustion engine having the cylinder head of claim 1.

7. The cylinder head of claim 2, wherein sealing of the at least one pre-chamber gas valve relative to the cylinder head or the spark plug sleeve is effected over a periphery of the at least one pre-chamber gas valve.

8. An internal combustion engine having the cylinder head of claim 2.

9. An internal combustion engine having the cylinder head of claim 3.

10. An internal combustion engine having the cylinder head of claim 4.

11. An internal combustion engine having the cylinder head of claim 5.

12. The cylinder head of claim 1, wherein a sharp transition exists between the valve bore and the plug bore.

13. The cylinder head of claim 1, wherein the valve bore blends fluidly in a smooth radius with the plug bore.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is illustrated in greater detail by the Figures in which:

(2) FIGS. 1a through 1c show a spark plug according to a first embodiment,

(3) FIGS. 2a through 2c show a spark plug sleeve according to a further embodiment,

(4) FIGS. 3a through 3e show a spark plug sleeve, with details relating to the gas feed concept,

(5) FIGS. 4a and 4b show a pre-chamber gas valve and a variant thereof, and

(6) FIG. 5 shows a situation as shown in FIG. 1a with fitted spark plug.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIGS. 1a through 1c show a spark plug sleeve 4 according to a first embodiment in three views.

(8) Thus, FIG. 1a shows a longitudinal section through the cavity 7 which accommodates a spark plug 6 (not shown) and a pre-chamber gas valve 5. In this embodiment, the cavity 7 is in a spark plug sleeve 4.

(9) The cavity 7 includes on the one hand a shaft which is concentric around the axis of symmetry S1, consisting of cylinder portions, for receiving a spark plug 6.

(10) The cavity 7 further has a bore 10 with an axis of symmetry S2 for receiving a pre-chamber gas valve 5.

(11) A passage 8 leads from the pre-chamber gas valve 5 to the pre-chamber 3. The pre-chamber 3 comprises on the one hand the actual cavity, that is to say the hollow space in which the ignition of mixture takes place. The pre-chamber 3 is of course also a physical component. In the present embodiment the pre-chamber 3 is in the form of a component separate from the spark plug sleeve 4 and is connected to the spark plug sleeve 4, for example by pressing.

(12) The spark plug 6 which is not shown for the sake of clarity is introduced into the spark plug sleeve 4 by way of the shaft concentric with the axis of symmetry S1, in such a way that it terminates flush with the pre-chamber 3 and its electrode(s) project into the pre-chamber 3. The pre-chamber 3 is enriched with combustion gas by the pre-chamber gas valve 5 by way of the passage 8. After ignition in the pre-chamber 3 ignited mixture passes by way of the flow transfer bores 9 into the main combustion chamber (not shown).

(13) FIG. 1b shows a plan view of the view in FIG. 1a. It is possible to see the parallel cylindrical shafts disposed within the cavity 7 for receiving a spark plug 6 and a pre-chamber gas valve 5. The spark plug 6 is not shown, as explained with reference to FIG. 1a. It is possible to see in the pre-chamber gas valve 5 an octagon with which the pre-chamber gas valve 5 is screwed into the spark plug sleeve 4.

(14) FIG. 1c shows a perspective view of the spark plug sleeve 4 of this embodiment.

(15) In the installed condition the spark plug sleeve 4 is fitted into a cylinder head 2 of an internal combustion engine (not shown here). The bore 10 of the pre-chamber gas valve 5 passes through the spark plug bore 11 in the upper portion thereof, of the largest diameter. That will be particularly clearly apparent from the views in FIGS. 1b and 1c. In a plan view (FIG. 1b) therefore the bore 10 for receiving the pre-chamber gas valve 5 and the bore for receiving the spark plug 6 overlap.

(16) FIGS. 2a through 2c show a further embodiment of a spark plug sleeve 4 which can be inserted into a cylinder head 2. Here the bores for receiving a spark plug 6 and for receiving the pre-chamber gas valve 5 pass through each other. In comparison with the embodiment shown in FIGS. 1a through 1c here the contour of the cavity 7 is altered. Here the contour of the cavity 7 is of such a configuration that the cylindrical bores for receiving the spark plug 6 and the pre-chamber gas valve 5 blend fluidly into each other. In other words, the sharp transitions of the embodiment of FIGS. 1a through 1c are here replaced by a smooth radius in the transition of the two bores.

(17) FIG. 3a shows a section through a spark plug sleeve 4, wherein the section was so positioned that the gas feed to the pre-chamber gas valve 5 is clearly illustrated. The section line is sketched in FIG. 3b. It is possible to see the gas feed passage 12, as it opens into the bore 10 carrying the pre-chamber gas valve 5. The bore 10 together with the pre-chamber gas valve 5 forms an annular passage 13 into which the gas feed passage 12 opens. From the annular passage 13 formed by the wall 10A and the pre-chamber gas valve 5, the inflowing gas is guided uniformly into the pre-chamber gas valve 5.

(18) FIG. 3c shows a longitudinal section through the spark plug sleeve 4. The section line can be seen from FIG. 3d. As can be seen from FIG. 3c the sectioning is here so selected that it is also possible to see the part of the gas feed passage 12, that extends parallel to the axis of symmetry S1.

(19) FIG. 3e is an isometric perspective view showing the arrangement of the pre-chamber gas valve 5 and its gas supply. The gas supply is afforded by the horizontal and the vertical portions of the gas feed passage 12.

(20) FIG. 4a shows a sectional view of the pre-chamber gas valve 5. It is possible to clearly see the annular passage 13 formed between the wall 10A of the cavity 7 and the outside contour of the pre-chamber gas valve 5. The wall 10A can be formed either by the cylinder head 2 itself or by a spark plug sleeve 4 fitted into the cylinder head 2.

(21) The valve needle 14 is braced against its seat by the spring 15. The cap 16 embraces the spring 15 and is connected to the valve needle 14 for example by way of a beam welding.

(22) The plug 17 closes and seals off the pre-chamber gas valve 5 upwardly. Sealing of the annular passage 13 with respect to the cavity 7 is effected radially by way of the O-rings 18. They are arranged in annular receiving means formed by the projections 19. The sealing concept of the pre-chamber gas valve 5 shown here therefore provides that sealing of the pre-chamber gas valve 5 is effected radially, that is to say by way of the outside surface of the pre-chamber gas valve 5.

(23) FIG. 4b shows a variant of FIG. 4a in which the space 23 is of a very substantially pear-shaped configuration narrowing towards the pre-chamber 3. That configuration is particularly advantageous from the fluidic point of view.

(24) FIG. 5 shows a view as shown in FIG. 1a, here with an illustrated spark plug 6.

LIST OF REFERENCES USED

(25) 2 cylinder head 3 pre-chamber 4 spark plug sleeve 5 pre-chamber gas valve 6 spark plug 7 cavity 8 passage 9 flow transfer bore 10 wall of the cavity 7 11 spark plug bore 12 gas feed passage 13 annular passage 14 valve needle 15 valve spring 16 cap 17 plug 18 O-ring 19 projection 20 gas passage 21 lower cavity of the pre-chamber gas valve 22 upper cavity of the pre-chamber gas valve 23 space 24 valve body S1 axis of symmetry S2 axis of symmetry