HIGH-PRESSURE LINE

Abstract

The invention relates to a high-pressure line for conveying a fluid under high pressure to a consumer, in particular for supplying fuel under injection pressure to one or more injectors (14) of a combustion engine. It comprises a first (1), a second (2), and a third line section (3), which line sections (1, 2, 3) are flowed through successively in the intended operation of the high-pressure line and are jointly formed by a ones-piece component (4) made of metal, wherein the first line section (1) and the third line section (3) each have a smaller flow cross-section than the second line section (2) arranged between them.

Claims

1-31. (canceled)

32. A combustion engine, in particular diesel or gas engine, with a high-pressure fuel pump permanently providing, in operation, fuel under injection pressure which is connected via high-pressure lines to the injectors (14) assigned to the single cylinders of the engine, wherein the injectors (14) of cylinders of the engine directly following one another are each connected to one another via high-pressure bridge lines (15) arranged between these, in particular of identical design, in such a way that the bridge lines (15) together form a continuous high-pressure line, and wherein the high-pressure fuel pump conveys into a high-pressure line which leads to one of the injectors (14) and from there feeds into a bridge line (15) leading away from this injector (14), wherein the bridge lines (15) have exactly one feed opening (7) and exactly one discharge opening (8), and wherein the bridge lines (15) comprise a first (1), a second (2), and a third line section (3), which line sections (1, 2, 3) are flowed through successively in the intended operation of the engine and are jointly formed by a one-piece metal component (4), wherein the first line section (1) and the third line section (3) each have a smaller flow cross-section, in particular a smaller line diameter, than the second line section (2) arranged between them.

33. The combustion engine according to claim 32, wherein the first (1) and the third line section (3) of the bridge lines (15) are arranged at the ends of the bridge lines and are constructed as connecting sections for pressure-tight connection of the bridge line to components (9, 10) supplying and discharging fuel, in particular with pressure rings (11) formed thereon or kneaded thereon.

34. The combustion engine according to claim 32, wherein the outer diameter of the bridge lines (15) in the region of the first line section (1) and of the third line section (3) is smaller than in the region of the second line section (2).

35. The combustion engine according to claim 32, wherein the line cross-section of the bridge lines (15) in the region of the second line section (2) is at least two times as large, in particular at least three times as large, as in the first line section (1) and in the third line section (3).

36. The combustion engine according to claim 32, wherein the volume of the second line section (2) of the bridge lines (15) is at least five times, in particular at least ten times, as large as the volume of the first (1) and the third line section (3) taken together.

37. The combustion engine according to claim 32, wherein the bridge lines (15) in the region of the second line section (2) have a ratio of outer diameter to inner diameter of larger than 1.5, in particular of larger than 2.5.

38. The combustion engine according to claim 32, wherein at the bridge lines (15) the one-piece component (4) is formed from a material with a tensile strength larger than 900 MPa, in particular larger than 1100 MPa.

39. The combustion engine according to claim 32, wherein at the bridge lines (15) the one-piece component (4) which forms the first (1), the second (2), and the third line section (3), is formed from a metal selected from the group consisting of quenched and tempered steel, a low-alloy steel, and an austenitic stainless steel of type X5CrNi18-10 (AISI 304), X2CrNiMo17-12-2 (AISI 316), X15CrMnNiN17-7-5 (AISI 201), X15CrMnNiN18-8-5 (AISI 202), X19CrMnNiCuN17-8-3-3 (AISI 204), X2CrNiMnMoNbN21-9-4-3, and X4CrNiMnMo21-9-4.

40. The combustion engine according to claim 32, wherein at the bridge lines (15) the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) is free of joining elements, in particular free of welding seams.

41. The combustion engine according to claim 32, wherein at the bridge lines (15) the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) is surrounded, at least in the region of the second line section (2), by one or more outer sheaths (4a, 4b) of an identical material or of a different material, in particular of another metal.

42. The combustion engine according to claim 41, wherein an outer sheath (4b) is provided which, together with the one-piece component (4) which forms the first (1), the second (2), and the third line section (3), forms a space (5) surrounding this one-piece component (4) for the controlled removal of possible leakage.

43. The combustion engine according to claim 41, wherein at the bridge lines (15) the outer diameter of an outer sheath (4a, 4b) surrounding the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) of the high-pressure line, in the region of the second line section (2) is more than two times, in particular more than three times, the inner diameter of the line.

44. The combustion engine according to claim 32, wherein at the bridge lines (15) a taper (6) of the line cross-section is present within the first (1), the second (2), and/or the third line section (3) for dampening pressure oscillations in the line.

45. The combustion engine according to claim 32, wherein at the bridge lines (15) the first (1) and the third line section (3) and a taper (6) in the first, the second, or the third line section, if any, has been formed by means of rotary swaging or based on rotary swaging.

46. The combustion engine according to claim 45, wherein at the bridge lines (15) the one-piece component (4) which forms the first (1), the second (2), and the third line section (3), has been formed from a pipe material, in particular produced by cold drawing or deep drilling, with the cross-section of the second line section by means of rotary swaging or based on rotary swaging.

47. The combustion engine according to claim 32, wherein the bridge lines (15) along their longitudinal extent, arranged one after another alternately comprise line sections (1, 3, 3a) with a smaller line cross-section or line diameter, respectively, and line sections (2a, 2b) with a larger line cross-section or line diameter, respectively.

48. The combustion engine according to claim 47, wherein the bridge lines have a single axial feed opening (7).

49. The combustion engine according to claim 32, wherein the bridge lines (15) are bent, in particular in the region of the second line section (2).

50. A bridge line for a combustion engine according to claim 32, comprising a first (1), a second (2), and a third line section (3), which line sections (1, 2, 3) are flowed through successively in the intended operation of the bridge line and are jointly formed by a one-piece component (4) of metal, wherein the first line section (1) and the third line section (3) each have a smaller flow cross-section, in particular a smaller line diameter, than the second line section (2) arranged between them, wherein the bridge line has exactly one feed opening (7) and exactly one discharge opening (8), and wherein the first (1) and the third (3) line sections are arranged at the ends of the bridge line and are constructed as connecting sections for pressure-tight connection of the bridge line to components (9, 10) supplying and discharging fuel, with pressure rings (11) kneaded thereon.

51. The bridge line according to claim 50, wherein the line cross-section of the line in the region of the second line section (2) is at least two times as large, in particular at least three times as large, as in the first (1) and/or in the third line section (3).

52. The bridge line according to claim 50, wherein the volume of the second line section (2) is at least five times, in particular at least ten times, as large as the volume of the first (1) and the third line section (3) taken together.

53. The bridge line according to claim 50, wherein the line in the region of the second line section (2) has a ratio of outer diameter to inner diameter of larger than 1.5, in particular of larger than 2.5.

54. The bridge line according to claim 50, wherein the one-piece component (4) of the line is formed from a material with a tensile strength larger than 900 MPa, in particular larger than 1100 MPa.

55. The bridge line according to claim 50, wherein the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) of the bridge line is made of a metal selected from the group of quenched and tempered steel, a low alloy steel, and an austenitic stainless steel of type X5CrNi18-10 (AISI 304), X2CrNiMo17-12-2 (AISI 316), X15CrMnNiN17-7-5 (AISI 201), X15CrMnNiN18-8-5 (AISI 202), X19CrMnNiCuN17-8-3-3 (AISI 204), X2CrNiMnMoNbN21-9-4-3, and X4CrNiMnMo21-9-4.

56. The bridge line according to claim 50, wherein the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) of the bridge line, is free of joining elements, in particular free of welding seams.

57. The bridge line according to claim 50, wherein the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) of the bridge line, is surrounded, at least in the region of the second line section (2), by one or more outer sheaths (4a, 4b) of an identical material or of a different material, in particular of another metal.

58. The bridge line according to claim 57, wherein an outer sheath (4b) is provided which, together with the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) of the bridge line, forms a space (5) surrounding this one-piece component (4) for the controlled removal of possible leakage.

59. The bridge line according to claim 57, wherein the outer diameter of an outer sheath (4a, 4b) surrounding the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) of the bridge line, in the region of the second line section (2) is more than two times, in particular more than three times, the inner diameter of the line.

60. The bridge line according to claim 50, wherein a taper (6) of the line cross-section is present within the first (1), the second (2), and the third line section (3), for dampening pressure oscillations in the line.

61. The bridge line according to claim 50, wherein the first (1) and the third line section (3) and any taper (6) in the first, the second, or the third line section, if any, has been formed by means of rotary swaging or based on rotary swaging.

62. The bridge line according to claim 61, wherein the one-piece component (4) which forms the first (1), the second (2), and the third line section (3) of the bridge line has been formed from a pipe material, in particular produced by cold drawing or deep drilling, with the cross-section of the second line section by means of rotary swaging or based on rotary swaging.

63. The bridge line according to claim 50, wherein the outer diameter of the bridge line in the region of the first (1) and/or the third line section (3) is smaller than in the region of the second line section (2).

64. The bridge line according to claim 50, wherein the bridge line along its longitudinal extent, arranged one after another alternately comprises line sections (1, 3, 3a) with a smaller line cross-section or line diameter, respectively, and line sections (2a, 2b) with a larger line cross-section or line diameter, respectively, and in particular wherein the line sections with larger line cross-section or line diameter, respectively, each comprise a radial discharge opening.

65. The bridge line according to claim 64, wherein the line has a single axial feed opening (7).

66. The bridge line according to claim 50, wherein the bridge line is bent, in particular in the region of the second line section (2).

67. A method for manufacturing a bridge line according to claim 50 comprising the steps of: a) providing a metal pipe with a substantially uniform pipe cross-section over the length of the pipe; and b) rotary swaging of the metal pipe on at least two spaced apart pipe sections for reducing the pipe cross-section in the region of these sections.

68. The method according to claim 67, wherein the rotary swaging is carried out in the region of the ends of the metal pipe.

69. The method according to claim 68, wherein a pressure ring is formed or kneaded onto the respective end of the metal pipe by means of the rotary swaging, by means of which a form-locking engagement in an axial direction is possible at the respective pipe end with fastening means for the purpose of connecting the pipe to a component.

70. The method according to claim 67, wherein the rotary swaging is carried out on several pipe sections, in particular uniformly spaced apart from one another, in the region between the ends of the metal pipe.

71. The method according to claim 67, wherein the rotary swaging is carried out at least in one pipe section in such a way that the pipe cross-section is reduced beyond the desired cross-section reduction and is subsequently enlarged to the desired cross-section dimension, in particular by means of drilling.

72. The method according to claim 67, wherein the rotary swaging is carried out at least in one pipe section in such a way that the pipe cross-section is kneaded around an inner tool, in particular around a mandrel, until the material fits completely against the tool, and the tool is subsequently removed in such a way that the remaining pipe cross-section in this region substantially corresponds to the tool cross-section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Further preferred embodiments of the invention result from the dependent claims as well as from the now following description on the basis of the figures. Thereby show:

[0050] FIG. 1 shows a longitudinal section through a first high-pressure feed line according to the invention;

[0051] FIG. 2 shows a longitudinal section through a second high-pressure feed line according to the invention;

[0052] FIG. 3 shows a longitudinal section through a third high-pressure feed line according to the invention;

[0053] FIG. 3a shows a section along line A-A in FIG. 3

[0054] FIG. 4 shows a longitudinal section through a first high-pressure bridge line according to the invention;

[0055] FIG. 5 shows a longitudinal section through one half of a second high-pressure bridge line according to the invention;

[0056] FIG. 6 shows a longitudinal section through a connection end of a high-pressure line according to the invention with a pressure ring kneaded thereon;

[0057] FIG. 7 shows a longitudinal section through a section of a first high-pressure collection line according to the invention;

[0058] FIG. 8 shows a longitudinal section through a section of a second high-pressure collection line according to the invention with connected high-pressure feed lines according to the invention;

[0059] FIG. 8a shows a section along the line B-B in FIG. 8;

[0060] FIG. 9 shows a section through two high-pressure bridge lines according to the invention connected to an injector; and

[0061] FIG. 10 shows a longitudinal section through part of a section of a third high-pressure collection line according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] FIG. 1 shows a longitudinal section through a first high-pressure injector feed line according to the invention of a common rail injection system of a diesel engine for connecting the injector to a high-pressure collection line of the injection system.

[0063] As can be seen, the high-pressure injector feed line has three line sections 1, 2, 3, which are, in the intended operation, flowed through one after the other by the diesel fuel which enters the line at the feed opening 7 and flows off to the injector via the discharge opening 8, and which are jointly formed by a one-piece pipe body 4 made of a low-alloy quenched and tempered steel of type 42CrMo4. The pipe body 4 is free of joining elements.

[0064] The first line section 1 and the third line section 3, which are formed at the ends of the high-pressure injector feed line and which are designed as straight pipe sections, each have a smaller line diameter than the second line section 2 arranged between them, which is designed as a 90 pipe elbow. The line diameter in the second line section 2 corresponds approximately to 2.5 times of the line diameter in the first 1 or third line section 3, respectively.

[0065] The second line section 2 is approximately the same length as the first 1 and the third line section 3 taken together, and its volume is more than five times as large as the volume of the first 1 and the third line section 3 taken together.

[0066] The first line section 1 and the third line section 3 have been formed by rotary swaging, and before rotary swaging had a cross-section identical to that of the second line section 2. Accordingly, the outer diameter of the high-pressure line in the region of the first line section 1 and the third line section 3 is smaller than in the region of the second line section 2, and the ratio of outer diameter to inner diameter in the region of the second line section 2 is approximately 1.6, whereas in the region of the first line section 1 and the third line section 3 it is approximately 3.4.

[0067] FIG. 2 shows a longitudinal section through a second high-pressure injector feed line according to the invention of a common rail injection system, which differs from the one shown in FIG. 1 only in that the third line section 3 has a taper 6 in the region of the discharge opening 8, for dampening of pressure oscillations in the line.

[0068] FIG. 3 shows a longitudinal section through a third high-pressure injector feed line according to the invention of a common rail injection system, and FIG. 3a shows a cross-section through the line along line A-A in FIG. 3. This high-pressure injector feed line differs from the one shown in FIG. 1 in that the one-piece component 4 forming the three line sections 1, 2, 3 has thinner walls and is made of tempered steel and is surrounded over its entire extent by an outer sheath 4a of austenitic stainless steel free of gaps. The thus resulting total wall thicknesses in the individual line sections 1, 2, 3 are approximately comparable to those of the high-pressure injector feed line from FIG. 1. Here, too, the first line section 1 and the third line section 3 have been formed by rotary swaging. Before rotary swaging, they had a cross-section identical to that of the second line section 2.

[0069] FIG. 4 shows a longitudinal section through a first high-pressure bridge line (also called jumper line) according to the invention of a common rail injection system of a diesel engine for connecting two injectors of the engine.

[0070] This high-pressure bridge line differs from the high-pressure injector feed line shown in FIG. 1 only in that it has a mirror-inverted shape in which the first and third line sections 1, 3 at the ends are formed identical and are oriented in the same direction and are connected to one another via a bow-shaped central second line section 2. Thereby, the second line section 2 is considerably longer than in the high-pressure injector feed line shown in FIG. 1, whereby its volume is correspondingly larger. Other than that, everything said above for the high-pressure injector feed line shown in FIG. 1 applies also to this high-pressure bridge line.

[0071] FIG. 5 shows a longitudinal section through one half of a second high-pressure bridge line according to the invention, which has the same mirror-inverted basic shape as the high-pressure bridge line shown in FIG. 4. The bridge line shown here differs from the line shown in FIG. 4 only in that, along its longitudinal extent, it comprises alternately arranged one after another line section with smaller line diameter 3, 3a and line sections with larger line diameter 2a, 2b, namely a total of five line sections with smaller line diameter (only two (3, 3a) and a part of a third are visible because of the representation of only one half of the line) and a total of four line sections with larger line diameter (only two (2a, 2b) are visible because of the representation of only one half of the line). The line sections 1, 3 at the ends (only the left line section 1 is visible due to the representation of only one half of the line) are identical to the ones shown in FIG. 4 at the high-pressure bridge line.

[0072] FIG. 6 shows a longitudinal section through a connecting section 3 at the end with a discharge opening 8 of a high-pressure line according to the invention as shown in the preceding figures with a pressure ring 11 kneaded thereon.

[0073] FIG. 7 shows a longitudinal section through a part of a first high-pressure collection line according to the invention of a common rail injection system of a diesel engine, with which several high-pressure feed lines for the injectors of the injection system are supplied.

[0074] As can be seen, the high-pressure collection line comprises a feed line section 1 with a feed opening 7, a distribution section 2 and, leading away from the distribution section 2, several discharge channels 3, each forming a discharge opening 8 of the collection line, for supplying the feed lines for the injectors to be connected thereto.

[0075] The feed line section 1, the distribution line section 2, and the discharge channels 3 are, in the intended operation, flowed through one after the other by the diesel fuel entering the collection line at the supply opening 7 and flowing out via the discharge openings 8 to the feed lines for the injectors and they are jointly formed by a one-piece pipe body 4 of a quenched and tempered low-alloy steel with a tensile strength larger than 900 MPa.

[0076] The feed line section 1 and the distribution section 2 are formed as straight pipe sections arranged one behind the other with coinciding center axes, while the discharge channels 3 branch off radially from the distribution section 2.

[0077] The feed line section 1 has a smaller line diameter than the distribution section 2, and the discharge channels 3 have smaller line diameters than the feed line section 1. The line diameter of the distribution section 2 is approximately two times the line diameter of the feed line section 1, whose line diameter is in turn approximately three times the line diameter of the discharge channels 3.

[0078] The feed line section 1 has been formed by rotary swaging, and had a cross-section identical to that of the distribution section 2 before rotary swaging. Accordingly, the outer diameter of the collection line in the region of the first feed line section 1 is smaller than in the region of the second distribution section 2. The ratio of outer diameter to inner diameter is approximately 2.0 in the region of the distribution section 2, while it is approximately 3.6 in the region of the feed line section 1.

[0079] The discharge channels 3 with the discharge openings 8 have been introduced into the wall of the distribution section 2 by means of drilling.

[0080] FIG. 8 shows a longitudinal section through a section of a second high-pressure collection line 12 according to the invention with connected high-pressure feed lines 13 according to the invention and FIG. 8a shows a section along line B-B in FIG. 8. The sectioning of FIG. 8 follows line C-C in FIG. 8a.

[0081] The high-pressure collection line 12 shown here differs from the collection line shown in FIG. 7 in that the one-piece pipe body 4, which forms the (not shown) feed line section, the distribution section 2 and the discharge channels 3 with the discharge openings, is surrounded in the regions between the connections 9, 10 of the high-pressure feed lines 13 by an outer sheath 4b made of metal, which together with the pipe body 4 forms a space 5 which surrounds the pipe body 4 for the controlled removal of possible leakage.

[0082] The high-pressure feed lines 13 shown here differ from the feed line shown in FIG. 3 in that the sheath 4a at the connection ends of the lines 13 is missing and instead a kneaded pressure ring 11 is provided, which serves to fasten the respective line end by means of a compression flange 9 to a fastening body 10 encompassing the high-pressure collection line 12.

[0083] FIG. 9 shows a section through two high-pressure bridge lines 15 (each only partially shown) according to the invention connected to an injector 14.

[0084] The high-pressure bridge lines 15 shown here differ from the bridge line shown in FIG. 4 in that, except for the connection ends, they are provided with a sheath 4a and at each connection end there is a kneaded pressure ring 11 which serves to fasten the respective line end by means of a coupling nut 9 to a connection block 10 of the injector 14.

[0085] FIG. 10 shows a longitudinal section through a part of a third high-pressure collection line according to the invention of a common rail injection system of a diesel engine, with which several high-pressure feed lines for the injectors of the injection system are supplied.

[0086] This high-pressure collection line differs from the collection line shown in FIG. 7 only in that the one-piece pipe body 4 which forms the feed line section 1, the distribution section 2, and the discharge channels 3 with the discharge openings 8, in the region of the distribution section 2 along its longitudinal extent comprises alternately arranged one after another line sections 6 with a smaller line diameter and line sections 2a, 2b, 2c with a larger line diameter. In this way, the storage section 2 forms several storage regions connected to each other by narrower sections, from each of which a radial discharge channel 3 with discharge opening 8 branches off. Accordingly, in the intended use of this high-pressure collection line, each of these storage regions 2a, 2b, 2c is assigned exactly to one injector, which it supplies with fuel via a single feed line connected to its radial discharge opening 8.

[0087] The tapered line sections 6 with the smaller line diameter have been produced by rotary swaging.

[0088] While in the present application preferred embodiments of the invention are described, it is to be clearly pointed out that the invention is not limited thereto and that it can also be carried out in another way within the scope of the following patent claims.