Injector arrangement

Abstract

The invention relates to an injector arrangement (1) having an injector nozzle (2) for injecting medium into a combustion chamber (3), particularly for injecting fuel into a combustion chamber (3) of an internal combustion engine, and having a sealing ring (20), which is pre-loaded in order to seal against a sealing surface (6) of a cylinder head (4), which comprises a through-hole (5), through which the injection nozzle (2) protrudes into the combustion chamber (3) and in which, in the radial direction between the injection nozzle (2) and the cylinder head (4), a heat protection sleeve (10) is arranged, one end (11) of which, facing the combustion chamber (3), is frictionally connected to the injection nozzle (2) by a radial pressing (12). In order to functionally improve the injector arrangement (1), an end (13) of the heat protection sleeve (10) furthest from the combustion chamber (3) is frictionally connected to the sealing ring (20) by an axial pressing (14).

Claims

1. An injector arrangement (1; 31; 41) with an injector nozzle (2) for injecting medium into a combustion chamber (3), in and with a sealing ring (20) which is preloaded in order to seal against a sealing face (6) of a cylinder head (4) comprising a passage hole (5), through which the injector nozzle (2) protrudes into the combustion chamber (3) and in which a heat protection sleeve (10) is arranged in a radial direction between the injector nozzle (2) and the cylinder head (4), one end (11) of which heat protection sleeve facing the combustion chamber (3) is connected by force fit to the injector nozzle (2) by a radial press fit (12), characterized in that an end (13) of the heat protection sleeve (10) facing away from the combustion chamber (3) is clamped in an axial direction against the sealing ring (20), wherein the end (13) of the heat protection sleeve (10) facing away from the combustion chamber (3) has a radially outwardly protruding collar (16), via which the heat protection sleeve (10) is clamped in the axial direction against the sealing ring (20), and wherein the sealing ring (20) has a radially inwardly protruding collar (22) which is clamped in the axial direction by the radially outwardly protruding collar (16) of the heat protection sleeve (10) against the sealing face (6) of the cylinder head (4).

2. The injector arrangement as claimed in claim 1, characterized in that the heat protection sleeve (10) is preloaded in the axial direction together with the sealing ring (20) against the sealing face (6) of the cylinder head (4).

3. The injector arrangement as claimed in claim 1, characterized in that an annular chamber (19), which is formed in the radial direction between the heat protection sleeve (10) and the cylinder head (4), is delimited at its end (13) facing away from the combustion chamber (3) in the axial direction by the radially outwardly protruding collar (16) of the heat protection sleeve (10).

4. The injector arrangement as claimed in claim 1, characterized in that an axial dimension of the radially inwardly protruding collar (12) of the sealing ring (20) is at least as large as an axial dimension of the radially outwardly protruding collar (16) of the heat protection sleeve (10).

5. The injector arrangement as claimed in claim 1, characterized in that a radial play is present between the radially outwardly protruding collar (16) of the heat protection sleeve (10) and the sealing ring (20).

6. The injector arrangement as claimed in claim 1, characterized in that the heat protection sleeve (10) comprises a sleeve body (32) which has the form of a straight hollow cylinder with an inner casing surface (33), via which the heat protection sleeve (10) is pressed over an entire axial dimension against an outer casing surface (34) of the injector nozzle (2).

7. The injector arrangement as claimed in claim 1, characterized in that the heat protection sleeve (10) and the sealing ring (20) are clamped in an axial direction against the sealing face (6) of the cylinder head (4) by a nozzle clamping nut (15).

8. An internal combustion engine comprising a combustion chamber (3), a cylinder head (4) including a sealing face (6) and a passage hole (5), and an injector arrangement (1; 31; 41) including an injector nozzle (2) for injecting fuel into the combustion chamber (3), the injector nozzle protruding into the combustion chamber through the passage hole, a sealing ring (20) which is preloaded in order to seal against the sealing face (6) of the cylinder head (4), and a heat protection sleeve (10) arranged in the passage hole in a radial direction between the injector nozzle (2) and the cylinder head (4), one end (11) of the heat protection sleeve facing the combustion chamber (3) being connected by force fit to the injector nozzle (2) by a radial press fit (12), and a clamping means clamps an end (13) of the heat protection sleeve (10) facing away from the combustion chamber (3) in an axial direction against the sealing ring (20).

9. The internal combustion engine as claimed in claim 8, characterized in that the heat protection sleeve (10) is preloaded in the axial direction together with the sealing ring (20) against the sealing face (6) of the cylinder head (4).

10. The internal combustion engine as claimed in claim 8, characterized in that the end (13) of the heat protection sleeve (10) facing away from the combustion chamber (3) has a radially outwardly protruding collar (16), via which the clamping means presses the heat protection sleeve (10) against the sealing ring (20).

11. The internal combustion engine as claimed in claim 10, characterized in that an annular chamber (19), which is formed in the radial direction between the heat protection sleeve (10) and the cylinder head (4), is delimited at its end (13) facing away from the combustion chamber (3) in the axial direction by the radially outwardly protruding collar (16) of the heat protection sleeve (10).

12. The internal combustion engine as claimed in claim 10, characterized in that the sealing ring (20) has a radially inwardly protruding collar (22) which is clamped in the axial direction by the clamping means between the radially outwardly protruding collar (16) of the heat protection sleeve (10) and the sealing face (6) of the cylinder head (4).

13. The internal combustion engine as claimed in claim 12, characterized in that an axial dimension of the radially inwardly protruding collar (12) of the sealing ring (20) is at least as large as an axial dimension of the radially outwardly protruding collar (16) of the heat protection sleeve (10).

14. The internal combustion engine as claimed in claim 10, characterized in that a radial play is present between the radially outwardly protruding collar (16) of the heat protection sleeve (10) and the sealing ring (20).

15. The internal combustion engine as claimed in claim 8, characterized in that the heat protection sleeve (10) comprises a sleeve body (32) which has the form of a straight hollow cylinder with an inner casing surface (33), via which the heat protection sleeve (10) is pressed over an entire axial dimension against an outer casing surface (34) of the injector nozzle (2).

16. The internal combustion engine as claimed in claim 8, wherein the clamping means is a nozzle clamping nut (15), and wherein the heat protection sleeve (10) and the sealing ring (20) are clamped in the axial direction against the sealing face (6) of the cylinder head (4) by the nozzle clamping nut (15).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The drawings show:

(2) FIG. 1 in longitudinal section, an injector arrangement with an injector nozzle and a heat protection sleeve which is connected, at an end facing the cylinder chamber, by force fit to the injector nozzle by means of a radial press fit, wherein an end of the heat protection sleeve facing away from the combustion chamber is connected by force fit to a sealing ring by means of an axial press fit;

(3) FIG. 2 an illustration similar to FIG. 1 with an optimized heat protection sleeve; and

(4) FIG. 3 an illustration similar to FIGS. 1 and 2 with a further optimized heat protection sleeve.

DETAILED DESCRIPTION

(5) FIGS. 1 to 3 show an injector arrangement 1; 31; 41 in three similar embodiments, each in longitudinal section. The same reference signs are used to designate the same or similar components. Firstly, the common features of the embodiments are described. Then the differences between the individual embodiments are explained.

(6) The injector arrangement 1; 31; 41 comprises an injector nozzle 2, which in FIGS. 1 to 3 protrudes with a lower end into a combustion chamber 3 of an internal combustion engine (not shown in detail). The internal combustion engine comprises a cylinder head 4 with a passage hole 5, through which the injector nozzle 2 protrudes into the combustion chamber 3.

(7) The cylinder head 4 has a sealing face 6 facing away from the combustion chamber 3. The sealing face 6 extends in a plane perpendicular to a longitudinal axis 8 of the injector nozzle 2. The injector nozzle 2 comprises a nozzle body 9 in which a nozzle needle (not visible or not shown) can be moved forward and back in the direction of the longitudinal axis 8, in order to open or close fuel delivery holes or openings (also not visible or not shown) in the nozzle body 9.

(8) The structure and function of the injector nozzle 2 may be the same as or similar to those of the fuel injector disclosed in European patent specification EP 3 014 105 B1 or the injector nozzle described in Austrian patent specification AT 512 667 B1.

(9) In the known fashion, a heat protection sleeve 10 is assigned to the nozzle body 9 of the injector nozzle 2. The heat protection sleeve 10 is made from material with good thermal conductivity, for example a copper alloy. Heat from the nozzle tip of the injector nozzle 2 is dissipated via the heat protection sleeve 10.

(10) An end 11 of the heat protection sleeve 10 facing the combustion chamber 3 is connected by force fit to the nozzle body 9 of the injector nozzle 2 by a radial press fit 12. An end 13 of the heat protection sleeve 10 facing away from the combustion chamber 3 is connected by force fit to a nozzle clamping nut 15 and a sealing ring 20 by an axial press fit 14. The sealing ring 20 is in turn connected to the cylinder head 4 by force fit. The nozzle clamping nut 15 serves to mount the injector nozzle 2 in the cylinder head 4 in the known fashion.

(11) At its end 13 facing away from the combustion chamber 3, the heat protection sleeve 10 has a collar 16. The collar 16 extends radially outwardly from a base body 17 of the heat protection sleeve 10. The base body 17 of the heat protection sleeve 10 has substantially the form of a straight hollow cylinder. The collar 16 has a rectangular ring cross-section. At its end 11 facing the combustion chamber 3, the heat protection sleeve 10 has an end portion 18 of reduced diameter.

(12) The end portion 18 of reduced diameter serves to create the radial press fit 12 between the heat protection sleeve 10 and the injector nozzle 2. The collar 16 of the heat protection sleeve 10 serves to create the axial press fit between the heat protection sleeve 10 and the sealing ring 20.

(13) The passage hole 5 in the cylinder head 4, together with the sealing ring 20, radially outwardly delimits an annular chamber 19 which is delimited radially inwardly by the heat protection sleeve 10. The annular chamber 19 is open towards the combustion chamber 3. At its end facing away from the combustion chamber 3, the annular chamber 19 is delimited by the collar 16 of the heat protection sleeve 10.

(14) The sealing ring 20 comprises a base body 21 with a rectangular ring cross-section. A collar 22 extends radially inwardly from the base body 21 of the sealing ring 20. The collar 22 of the sealing ring 20 is clamped by force fit in the axial direction between the collar 16 of the heat protection sleeve 10 and the sealing face 6 of the cylinder head 4.

(15) The axial press fit 14 connects the heat protection sleeve 10 by force fit to the sealing ring 20, which itself is connected by force fit to the cylinder head 4. In this way, an axial press-fit connection is created which securely prevents combustion gas from escaping from the combustion chamber 3, through the annular chamber 19, into a structurally provided annular chamber 23.

(16) The annular chamber 23 in FIGS. 1 to 3 is delimited axially at the bottom by the collar 22 of the sealing ring 20. The annular chamber 23 is delimited axially at the top by the nozzle clamping nut 15. The annular chamber 23 results from a structurally required radial play between the collar 16 of the heat protection sleeve 10 and the base body 21 of the sealing ring 20.

(17) In the injector arrangements 31; 41 of FIGS. 2 and 3, the heat protection sleeve 10 comprises a sleeve body 32 which has the form of a straight hollow cylinder. An inner casing surface 33 of the sleeve body 32 bears over its entire axial dimension (also known as the length) on an outer casing surface 34 of the nozzle body 9 of the injector nozzle 2 by force fit, in order to create the radial press fit 12. At its end 11 facing the combustion chamber 3, the sleeve body 32 has an end portion 18 of reduced diameter.

(18) In the injector arrangement 41 in FIG. 3, in contrast to FIG. 2, the sleeve body 32 is designed without the end portion 18 of reduced diameter. Otherwise, the heat protection sleeve 10 in FIG. 3 is designed in the same fashion as in FIG. 2.