METHOD FOR MANUFACTURING AN INJECTOR FOR INJECTING FUEL

Abstract

A method for manufacturing an injector for injecting fuel, the injector including: a closing body which is linearly movable in an axial direction and a valve seat element having at least one passage for injecting the fuel, a valve seat with which the closing body is in contact for closing off the at least one passage, and a guide area for guiding the closing body when same is moving in the axial direction, the method being characterized in that the valve seat and the guide area are hard turned.

Claims

1-10. (canceled)

11. A method for manufacturing an injector for injecting fuel, the method comprising: providing a closing body, which is linearly movable in an axial direction and a valve seat element, having at least one passage for injecting the fuel, a valve seat with which the closing body is in contact for closing off the at least one passage, and a guide area for guiding the closing body when it is moving in the axial direction; and hard turning the valve seat and the guide area.

12. The method of claim 11, wherein contours of the valve seat and of the guide area are initially soft turned, wherein subsequently, the valve seat element is hardened at least at the valve seat and at the guide area, and wherein after the hardening, the valve seat and the guide area are hard turned.

13. The method of claim 11, wherein the guide area includes several grooves and webs situated in-between, the closing body being in contact with the webs and all of the webs being simultaneously hard turned.

14. The method of claim 11, wherein the valve seat and the guide area are hard turned when the valve seat element is clamped.

15. An injector for injecting fuel, comprising: a closing body, which is linearly movable in an axial direction and a valve seat element, having at least one passage for injecting the fuel, a valve seat with which the closing body is in contact for closing off the at least one passage, and a guide area for guiding the closing body when it is moving in the axial direction; wherein the valve seat and the guide area are hard turned.

16. The injector of claim 15, wherein the valve seat element has a material hardness of at least 440 HV10 at the valve seat and at the guide area.

17. The injector of claim 15, wherein the valve seat has a valve seat diameter perpendicular to the axial direction, the valve seat diameter being maximally 3 mm.

18. The injector of claim 15, wherein the guide area has a guide diameter perpendicular to the axial direction, the guide diameter being maximally 5 mm.

19. The injector of claim 15, wherein a minimum wall thickness is defined at the valve seat element, the minimum wall thickness corresponding to the length of the passage, with only that area of the passage being taken into account which has the smallest passage diameter, and the minimum wall thickness being maximally 0.8 mm.

20. The injector of claim 15, wherein the valve seat and the guide area are situated coaxially to one another, the coaxiality deviating by maximally 0.03 mm.

21. The injector of claim 15, wherein the valve seat element has a material hardness of at least 500 HV10 at the valve seat and at the guide area.

22. The injector of claim 15, wherein the valve seat element has a material hardness of at least 550 HV10, at the valve seat and at the guide area.

23. The injector of claim 15, wherein the valve seat has a valve seat diameter perpendicular to the axial direction, the valve seat diameter being maximally 2 mm.

24. The injector of claim 15, wherein the guide area has a guide diameter perpendicular to the axial direction, the guide diameter being maximally 4 mm.

25. The injector of claim 15, wherein a minimum wall thickness is defined at the valve seat element, the minimum wall thickness corresponding to the length of the passage, with only that area of the passage being taken into account which has the smallest passage diameter, and the minimum wall thickness being maximally 0.7 mm.

26. The injector of claim 15, wherein a minimum wall thickness is defined at the valve seat element, the minimum wall thickness corresponding to the length of the passage, with only that area of the passage being taken into account which has the smallest passage diameter, and the minimum wall thickness being maximally 0.6 mm.

27. The injector of claim 15, wherein the valve seat and the guide area are situated coaxially to one another, the coaxiality deviating by maximally 0.02 mm.

28. The injector of claim 15, wherein the valve seat and the guide area are situated coaxially to one another, the coaxiality deviating by maximally 0.01 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 shows a sectional view of an injector according to the present invention manufactured according to the method according to the present invention according to one exemplary embodiment.

[0020] FIG. 2 shows a detailed view of FIG. 1.

DETAILED DESCRIPTION

[0021] An injector 1 according to one exemplary embodiment of the present invention is described in detail below with reference to FIGS. 1 and 2. Injector 1, in particular a valve seat element 8 of injector 1, is manufactured according to the method according to the present invention.

[0022] FIG. 1 shows complete injector 1 in the assembled state. Injector 1 is situated in this case in a bore of an internal combustion engine 2, in particular in a cylinder head. FIG. 2 shows in detail the combustion chamber-side end of injector 1. Injector 1 includes a valve sleeve 3. In valve sleeve 3, a closing body 5 is accommodated linearly movably in an axial direction 4. Closing body 5 includes a rod 6 and a ball 7. Ball 7 is fastened to rod 6 on the combustion chamber side.

[0023] Furthermore, a mechanism 17 is situated in valve sleeve 3. Rod 6 of closing body 7 is fastened in this mechanism 17. Mechanism 17 is used to linearly move closing body 5 and thus to open and close injector 1.

[0024] Injector 1 further includes a valve seat element 8. Valve seat element 8 is accommodated in valve sleeve 3 and connected to valve sleeve 3 via a weld seam 18. Valve seat element 8 includes a hollow space in which ball 7 of closing body 5 is accommodated. At the side of ball 7, a guide area 11 is formed in valve seat element 8 for guiding closing body 5. Furthermore, valve seat element 8 includes a valve seat 10. In the closed state of injector 1, ball 7 sits on valve seat 10.

[0025] Passages 9 are formed at the combustion chamber-side end of valve seat element 8. Guide area 11 includes several webs 13 which are spaced apart from one another by grooves 12. Ball 7 is in contact with webs 13. The fuel to be injected flows through grooves 12 and passages 9 into the combustion chamber.

[0026] Valve seat 10 as well as guide area 11, in particular the side of webs 13 facing inward, were hard turned. For this purpose, the contours of valve seat 10 and of guide area 11 were initially manufactured by soft turning. Subsequently, valve seat element 8 was hardened and hard turned.

[0027] FIG. 2 further shows a valve seat diameter 14. Valve seat diameter 14 is measured perpendicularly to axial direction 4 and is defined by a contact surface of ball 7 on valve seat 10 in the closed state of injector 1.

[0028] Furthermore, FIG. 2 shows a guide diameter 15 which corresponds to the distance between opposing webs 13 of guide area 11 or to a diameter of ball 7.

[0029] According to FIG. 2, passages 9 include an inner area having a very small passage diameter. This area defines a minimum wall thickness 16 of valve seat element 8.

[0030] Valve seat diameter 14, guide diameter 15, minimum wall thickness 16 as well as the hardness of the material at guide area 11 and valve seat 10 may be selected in the same way as described in the general part of the description and in the subclaims.