EP1260704B1 - Accumulator fuel injection system with high pressure components having an increased mechanical strength - Google Patents

Description

The present invention relates to a storage injection system with increased component strength of high-pressure Components and in particular a common rail system.

Storage injection systems, such as Common rail systems are known from the prior art. Recently in particular increased requirements with regard to higher system pressures up to 2000 bar. The thereby caused high dynamic pressure requirements set for the used Components are high loads. In particular, the rail due to its fuel storage function and the associated large inner diameter a vulnerability in the common rail systems. Here are in particular the existing on the rail bore intersections between the Longitudinal bore, which fulfills the fuel storage function, and the cross bores leading to the injectors critical.

A known from the prior art storage injection system is shown for example in FIG. The known Storage injection system comprises a high-pressure pump 2, which connected via a line 15 with a manifold 17 is. From the manifold 17 lead lines 5 each to one Rail 12. The rail 12 is via lines 14 each with connected to an injector 4. The Rail 12 takes over both the distribution function of the fuel as well Storage function of the fuel. For this purpose, in the rail 12 a Longitudinal bore formed with a large diameter to one be able to record correspondingly large fuel volume. Furthermore, the manifold 17 is a pressure measuring device 16 arranged.

Distinguish in the known storage injection systems The cross-sectional areas of the rail and the lines are around a factor of about 15, so that the rail takes much higher is called the wires. This particular arise due to unfavorable superpositions of high voltages at the intersection between longitudinal and transverse bore Durability issues. Therefore, for example elaborate edge rounding in the intersection area executed or it must be expensive, high-strength materials be used, which is correspondingly expensive to edit are and thus increase the cost of the storage injection system. Furthermore, elaborate adjustments of angles between realized the holes or in the rail from inside compressive stresses, for example by means of autofrettage or by means of Shot blasting introduced. Furthermore, residual compressive stresses for example, by shrinking of wraps introduced into the rail. However, these measures are very consuming and expensive the production of the storage injection system.

It is therefore an object of the present invention, a storage injection system to provide, which in a simple Structure and simple, cost-effective manufacturability a increased component strength of high-pressure components allows.

This object is achieved by a storage injection system with the Features of claim 1 and a use according to the features of claim 7 solved. Advantageous developments are the subject of the dependent claims.

The storage injection system according to the invention is constructed in such a way that there is a high pressure pump, one with the high pressure pump having connected distributor and a plurality of injectors. The injectors are each with the manifold over Lines connected. The lines have such a Length up to a certain fuel storage volume have to memory function in the storage injection system to fulfill. Thus, according to the invention on the rail or on the existing in the art in the rail Storage volume can be dispensed with, so that with it connected strength problems in the rail due to the large Hole diameter for the storage volume are eliminated. According to the memory function is through the lines accepted. The lines can also be a little larger Diameter than previously in storage injection systems have used lines, whereby the line length be reduced slightly for a predetermined volume can. This is according to the invention in the prior art fuel storage function adopted by the rail on the Distributed cables. As a result, in the storage injection system only components with relatively small diameters exist, so that the load on the individual components are reduced can. By using the lines as memory of the This memory injection system can thus be particularly cost-effective getting produced. Furthermore, a more variable arrangement the individual components of the storage injection system possible in the engine compartment.

Preferably, the manifold has a longitudinal bore, whose diameter is equal to the diameter of the pipes or whose diameter is only slightly larger than the pipe diameter is. This ensures that problematic Pressure peaks in the distributor, in particular on Intersection between the longitudinal bore and the transverse bores do not occur. Equally possible, however, is the Using a manifold with a slightly smaller Inner diameter than that of the lines. So can eg. the inner diameter of the distributor is about 15% smaller its than the inner diameter of the lines.

According to a particularly preferred embodiment of the present invention Invention is the longitudinal bore in the manifold arranged eccentrically to the distributor piece longitudinal axis. Thereby Is it possible that the manifold is particularly small and small is compact and has a low weight. The Eccentricity is chosen such that there is still a sufficient Wall thickness of the distributor between the longitudinal bore and the outside is present. Thus, the manifold especially with regard to weight optimization be interpreted.

To further reduce the loads on the distributor, the lines on the manifold are preferably by means of adapters fastened, which screwed into the manifold are. This will be by screwing the adapter compressive stresses at the intersection between the longitudinal bore and the transverse bore of the distributor introduced, so that the load in the intersection area is further reduced can be.

According to a further preferred embodiment of the present invention Invention is between the manifold according to the invention and the injectors a second manifold without Storage volume arranged. This is the storage injection system practically according to the known structure of Storage injection systems with a manifold and a Rail (second manifold), wherein the inventive Rail, however, does not take over storage function because the memory function of the lines of the storage injection system be taken over. Particularly preferred are the two distributor pieces constructed identically, so that the number increased by equal parts in the storage injection system can be, thereby reducing the manufacturing cost to let. Unused connections on the manifolds can in each case by means of plugs o.ä. be closed. Thus, according to the invention, the component strength of the high-pressure Components of the storage injection system increased Be by only components with holes with relative small diameter can be used. The fuel storage function is completely or partially from the lines accepted. Thus, according to the invention on the one hand the met increased pressure requirements on storage injection systems and on the other hand, the individual components be made cheaper. By eliminating the Rails further result in a reduced space and a reduced weight of the storage injection system. Also is a more flexible arrangement of the manifold in the storage injection system possible.

According to the invention thus the lines in a storage injection system to provide the entire storage volume for the storage function in the storage injection system used. Thus take over the lines (instead of the Rails) the memory function in the system, reducing the number of components can be reduced.

Figur 1 eine schematische Draufsicht eines Speichereinspritzsystems gemäß einem ersten Ausführungsbeispiel der vorliegenden Erfindung,

Figur 2 eine schematische Schnittansicht eines Verteilerstücks gemäß dem ersten Ausführungsbeispiel der vorliegenden Erfindung,

Figur 3 eine Schnittansicht entlang der Linie A-A in Figur 2,

Figur 4 eine schematische Teilschnittansicht eines Speichereinspritzsystems gemäß einem zweiten Ausführungsbeispiel der vorliegenden Erfindung,

Figur 5 eine Schnittansicht entlang der Linie B-B in Figur 4 und

Figur 6 eine schematische Ansicht eines Speichereinspritzsystems gemäß dem Stand der Technik.

The invention will be described by means of preferred embodiments in conjunction with the drawing. In the drawing is:

FIG. 1 is a schematic plan view of a storage injection system according to a first embodiment of the present invention;

FIG. 2 is a schematic sectional view of a manifold according to the first embodiment of the present invention;

FIG. 3 shows a sectional view along the line AA in FIG. 2,

FIG. 4 shows a schematic partial sectional view of a storage injection system according to a second exemplary embodiment of the present invention,

Figure 5 is a sectional view taken along the line BB in Figure 4 and

Figure 6 is a schematic view of a storage injection system according to the prior art.

Hereinafter, with reference to Figures 1 to 3 a First embodiment of the present invention described.

As shown in Figure 1, the storage injection system 1 according to the first embodiment, a high-pressure pump 2, which is connected via a line 6 with a manifold 3 is. From the manifold 3 go a variety of lines 5, which in each case with an injector 4 for injection connected by fuel. The distributor piece 3 takes over only the distribution function for the fuel. The Memory function of the storage injection system is respectively taken from the lines 5, which has a predetermined length and have a predetermined diameter to this To fulfill memory function.

The diameter of the lines 5 is not too large, not to exceed certain loads on the lines. For example, the lines 5 have a diameter of about 3.0 mm. Thus, in the inventive Storage injection system on that used in the prior art Rail will be omitted, which in addition to the distribution function at the same time still the fuel storage function takes over and therefore a relatively large space for Fuel storage, on which the above-described Strength problems can occur.

In FIG. 2, the distributor 3 according to the invention is in one enlarged sectional view shown. As shown in FIG. 2, is in the manifold 3 along the manifold longitudinal axis X-X introduced a longitudinal bore 7. The longitudinal bore 7 has the same diameter as the diameter of the lines 5. From the longitudinal bore 7 go more Transverse holes 8 from which also the same diameter as the longitudinal bore 7 have. The transverse bores 8 are thereby formed as stepped holes and have at their the longitudinal bore 7 opposite end one with a thread 9 provide area of larger diameter (see. Figure 2).

As can be seen from Figure 2, is in this threaded area 9 screwed an adapter 10 for fixing a line 5. The adapter 10 is thereby in the thread. 9 screwed that in the intersection between the Longitudinal bore 7 and the transverse bore 8 additional compressive residual stresses be introduced so that the component strength can be further increased in this intersection area. In this case, the adapter 10 is designed such that it is screwed in Condition at the bottom of the threaded stepped Bore 9 rests.

Thus, the inventive lines 5 are compared with the leads in the prior art much longer, to the entire memory function in the storage injection system to take over. This allows the high dynamic Printing requirements are met and the invention Storage injection system has a significantly extended Life on. Furthermore, it can be a time-consuming post-processing omitted the components of the storage injection system so that the manufacturing costs are significantly reduced can be.

In FIGS. 4 and 5, a storage injection system according to FIG a second embodiment of the present invention shown. Same or functionally identical parts are with the same reference numerals as in the first embodiment designated.

In contrast to the first embodiment are in the second Embodiment next to the manifold 3, which directly is arranged adjacent to the high-pressure pump 2, there are also further second distributor pieces 13 (in FIG. 4) is for clarity of presentation only another second Distributor piece 13 shown). The second distributor 13 is arranged at the position at which in the state of Technique usually the rail is arranged. It points however, the second distributor 13 does not correspond to the rail Memory function on, but only for distribution of the fuel to the individual injectors 4.

The second distributor 13 is similar to that in FIG. 2 shown distributor piece 3, wherein in difference For this purpose, the longitudinal bore 7 of the second manifold 13 eccentric is arranged to the distributor piece longitudinal axis X-X (see Figure 5). As a result, in particular the size and thus the weight of the manifold 13 are optimized because the Longitudinal bore 7 relatively close to the outer periphery of the manifold 13 can be arranged. The diameter of the longitudinal bore 7 corresponds again to the diameter of the lines 5th

Further, in Figure 4 are still connecting lines 11 between the second manifold 13 and the injectors 4 shown. These connecting lines 11 are the same as the Lines 5 constructed and have a length of about 300 mm on. In this case, part of the storage function of the storage injection system also taken from these lines 11 become. It should be noted, however, that the injectors 4 as possible should be arranged close to the manifold 13. However, through longer connecting lines 11 additional Degrees of freedom with regard to a more variable arrangement of the individual components.

Thus, the present invention relates to a storage injection system with a high pressure pump 2, one with the high pressure pump 2 connected manifold 3 and multiple injectors 4. The injectors 4 are connected to the manifold 3 respectively connected via lines 5. The lines 5 have a such length as to have a predetermined fuel storage volume have and thus the memory function in the storage injection system can take over. This can be done on the Rail used in the prior art can be dispensed with.

The preceding description of the embodiments according to The present invention is for illustrative purposes only and not for the purpose of limiting the invention. As part of The invention has various changes and modifications possible, without the scope of the invention as in the Claims to leave defined.

Claims (7)

1. A storage injection system comprising a high-pressure pump (2), a manifold (3) which is connected to the high-pressure pump (2), and a plurality of injectors (4) which are connected to the manifold (3) via lines (5) in each case, wherein the manifold (3) assumes only the distributing function for the fuel and the length of the lines (5) is such that they have a predetermined fuel-storage volume in order largely to assume the overall storage function of the storage injection system.
2. The storage injection system as claimed in Claim 1, characterized in that the manifold (3) has a longitudinal hole (7) whose diameter corresponds to the diameter of the lines (5) or whose diameter is only slightly larger than the diameter of the lines (5).
3. The storage injection system as claimed in Claim 1 or 2, characterized in that the longitudinal hole (7) in the manifold (3) is arranged eccentrically in relation to a longitudinal axis of the manifold (X-X).
4. The storage injection system as claimed in one of the Claims 1 to 3, characterized in that the lines (5) are fastened to the manifold (3) by means of adapters (10), wherein said adapters (10) are screwed into the manifold (3) in such a way that pressure residual stresses are introduced at an intersection between the longitudinal hole (7) and a transverse hole (8).
5. The storage injection system as claimed in one of the Claims 1 to 4, characterized in that a second manifold (13) for distributing fuel to the injectors (4) is arranged between the manifold (3) and the injectors (4).
6. The storage injection system as claimed in Claim 5, characterized in that the manifold (3) and the second manifold (13) are identical in structure.
7. A use of lines (5) in a storage injection system, for providing the overall storage volume for assuming the storage function in the storage injection system.

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