Component for an injection system, and injection system for mixture-compressing, applied-ignition internal combustion engines, and method for producing a component of this type

Abstract

The invention relates to a component (3), in particular fluid distributor (2), for an injection system (1) for mixture-compressing, applied-ignition internal combustion engines which apportions a fluid which is under high pressure, having a main part (14) and at least one connection piece (16A-19A) formed on the main part (14) which connects an injection valve (7-10), wherein the injection valve (7-10) can be inserted into a receiving chamber (27-30) of the connection piece (16A-19A) along an assembly axis (40-43) during assembly, wherein at least the main part (14) and the connection piece (46-49) are formed by single or multi-stage forging and wherein a recess (51, 51') is formed on an outside (52, 52') of the connection piece (46-49), into which, in an assembled state, an orientation element (50) of the injection valve (7-10) engages in order to restrict a degree of freedom of rotation of the injection valve (7-10) about the assembly axis (40-43). According to the invention, the connection piece (16A-19A) is reworked after forging such that at least one lateral face (56, 57, 56', 57') of the recess (51, 51') of the connection piece (16A-19A) on which, in the assembled state, in order to restrict a degree of freedom of rotation in a selected rotation direction (49) about the assembly axis (40-43), a contact between the orientation element (50) of the injection valve (7-10) and the connection piece (16-19A) is enabled, is designed at least approximately having a specified side height (58). Furthermore, the invention relates to an injection system having such a component (3) and to a method for producing such a component (3).

Description

State of the art

[0001] The invention relates to a component, in particular a fuel distributor, for an injection system used for mixture-compressing, spark-ignition internal combustion engines. Specifically, the invention relates to the field of injection systems for motor vehicles in which fuel is injected directly into the combustion chambers of an internal combustion engine.

[0002] From DE 10 2018 110 342 A1, a fuel distributor with a pressure storage tube is known, wherein the pressure storage tube has a forged base body. Flange pieces are provided on the base body, which are formed integrally with the base body by forging and are provided with mounting openings.

[0003] Another fuel distributor is known from CN 109 139 318 A. Disclosure of the invention

[0004] The component according to the invention with the features of claim 1, the injection system according to the invention with the features of claim 6 have the advantage that an improved design and function are made possible.

[0005] The measures listed in the dependent claims enable advantageous further developments of the component specified in claim 1 and the injection system specified in claim 6.

[0006] The injection system according to the invention is used for mixture-compressing, spark-ignition internal combustion engines. The injection system according to the invention is used for injecting gasoline and / or ethanol and / or comparable fuels and / or for injecting a mixture containing gasoline and / or ethanol and / or comparable fuels. The mixture may, for example, be a mixture with water. The component according to the invention is used for such injection systems.

[0007] At least the base body of the component is made of a material, preferably a stainless steel, in particular an austenitic stainless steel. Specifically, the material may be based on an austenitic stainless steel with material number 1.4301 or 1.4307, or on a comparable stainless steel. Austenitic steels with material numbers 1.4301, 1.4306, 1.4307, and 1.4404 may be used. Hydraulic connections provided on the base body may each be configured as a high-pressure inlet, high-pressure outlet, or other high-pressure connection. Preferably, the base body, together with a high-pressure inlet, at least one high-pressure outlet realized on the connection nozzle, and optionally one or more other high-pressure connections, is then formed and further machined as a forged blank during manufacturing.

[0008] The proposed design of a fuel rail differs significantly from a soldered rail, where a tube is machined and deburred before the components are soldered on. The forged design allows for a configuration suitable for higher pressures. A key difference from a high-pressure rail for compression-ignition internal combustion engines lies in the material selection and processing, particularly the forging of stainless steel.

[0009] The proposed post-processing of the connecting stub, which takes place after forging, advantageously allows for a consistent side height to be achieved on connecting stubs of multiple components. In particular, an advantageous embodiment according to claim 2 can be realized. Specifically, a side height can be specified such that at least a minimum height required for the function of restricting the rotational degrees of freedom is achieved.

[0010] In series production, the specified side height, which is at least as high as a minimum height, can be uniformly defined across a large number of components. Due to tolerances, variations in component size occur after forging at individual connection spigots and at connection spigots of different components, resulting in deviations between the geometries of the connection spigots. Post-forging processing is preferably carried out in such a way that consistent shapes of the side surfaces of the connection spigot recess are achieved. With the proposed design, functional deburring enables simplified machining with reduced commissioning, correction, and measurement efforts.

[0011] Variations in the geometry of the individual connection spigots are achieved by means of edge removal of variable size.

[0012] Post-processing can be based on a functional and tolerance analysis to ensure the required function and to cover the variations in component size caused by tolerances.

[0013] The geometry and / or size of the resulting edge can then vary depending on the deviation of the component's outer contour. Since the design criterion for machining is ensuring the required functional surfaces on the side faces, deviations in the geometries of the connection nozzles on a fluid distributor or between several fluid distributors result in different geometries of the realized edges during series production. Advantageously, a further development according to at least one of claims 3 or 4 is therefore carried out. It is particularly advantageous if the at least one side face and the edge are produced by a single tool in one process step, as is possible according to the advantageous further development according to claim 5. In a modified embodiment, however, the side faces and the edge can also each be machined with individual tools. Brief description of the drawings

[0014] Preferred embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawings, in which corresponding elements are provided with matching reference numerals. The drawings show: Fig. 1 an injection system for a mixture-compressing, spark-ignition internal combustion engine with a component designed as a fuel distributor in a schematic sectional view according to an embodiment of the invention; Fig. 2 the in Fig. 1 Section of the component designated II according to the exemplary embodiment in a detailed, schematic representation; Fig. 3 a detail of a connecting piece of the in Fig. 2 component shown according to the embodiment of the invention; Fig. 4 a cut along the in Fig. 2 The section line marked IV through a recess of a connecting piece in comparison to another conceivable post-processing to illustrate the embodiment of the invention in a schematic representation, as well as Fig. 5A und Fig. 5B Schematic, partial representations of a connecting piece and another connecting piece of the in Fig. 1 The component shown illustrates a possible embodiment of the invention. Embodiments of the invention

[0015] Fig. 1 Figure 1 shows a schematic sectional view of an injection system 1 with a fuel distributor (fluid distributor) 2, corresponding to a first embodiment. In this embodiment, the fuel distributor 2 of the fuel injection system 1 is a component 3 designed according to the invention. A high-pressure pump 4 is also provided. The high-pressure pump 4 is connected to the fuel distributor 2 via a fuel line 5 designed as a high-pressure line 5. During operation, a fuel or a fuel mixture is supplied as a fluid to an inlet 6 of the high-pressure pump 4.

[0016] The fuel distributor 2 serves to store and distribute the fluid to the fuel injectors 7 to 10, which are designed as fuel injectors 7 to 10, and reduces pressure fluctuations and pulsations. The fuel distributor 2 can also serve to dampen pressure pulsations that can occur when the fuel injectors 7 to 10 are switched. During operation, high pressures p can occur, at least temporarily, in an interior space 11 of component 3.

[0017] The fuel distributor 2 has a tubular base body 14, which is formed by a single- or multi-stage forging process. Component 3 has a tubular base body 14, a high-pressure inlet 15, and several hydraulic connections 16 to 19, designed as high-pressure outlets 16 to 19, provided on the tubular base body. A pressure sensor connection 20 is also provided on the tubular base body 14. In this embodiment, the tubular base body 14, the high-pressure inlet 15, connection ports 16A to 19A for the high-pressure outlets 16 to 19, and the pressure sensor connection 20 are formed from a single forged component 14'. The high-pressure inlet 15, the connection ports 16A to 19A for the high-pressure outlets 16 to 19, and the pressure sensor connection 20 are thus forged onto the base body 14.

[0018] The fuel injectors 7 to 10 are each connected to the high-pressure outlets 16 to 19 of the fuel distributor 2. A pressure sensor 21 is also provided, which is connected to the pressure sensor port 20. At one end 22, the tubular base body 14 is closed by a closure 23, which in this embodiment is designed as a sealing screw 23. The end 22 of the tubular base body 14 can be designed as a threaded fitting 22A. In a modified embodiment, an axial high-pressure inlet can be provided at the end 22 or at one end 24 instead of the radial high-pressure inlet 15.

[0019] After forging, the tubular base body 14 or the forged component 14' is machined by at least one machining operation. In this embodiment, a bore 25 is formed in the tubular base body 14 after forging to create the interior 11. During operation, the fluid supplied at the high-pressure inlet 15 can be distributed via the interior 11 to the fuel injection valves 7 to 10 connected to the high-pressure outlets 16 to 19.

[0020] Furthermore, bores 26 to 31 are machined into the forged component 14'. Bores 27 to 30 serve as connecting bores for the high-pressure outlets 16 to 19. Bore 26 serves for the high-pressure inlet 15. Bore 31 serves for the pressure sensor connection 20. Additionally, an internal thread 22B is cut into bore 25 at the end 22 of the base body 14, forming the threaded fitting 22A.

[0021] Furthermore, bores 32 to 37 can be provided at the high-pressure inlet 15, the connection ports 16A to 19A of the high-pressure outlets 16 to 19, and the pressure sensor connection 20. In this embodiment, bore 25 is oriented axially with respect to a longitudinal axis 38. Bores 32 to 37 are oriented radially with respect to the longitudinal axis 38 in this embodiment. An outer surface 39 of the base body 14 can be based on a cylindrical shell-shaped base form.

[0022] In the schematic representation of the Fig. 1 The bores 33 to 36 are oriented radially with respect to the longitudinal axis 38. In possible embodiments of the invention, the bores 33 to 36 are preferably oriented radially or radially eccentrically with respect to the longitudinal axis 38. The bores 33 to 36 of the connecting nozzles 16A to 19A then define mounting axes 40 to 43 for the injection valves 7 to 10. The mounting axes 40 to 43 are then preferably oriented radially or radially eccentrically with respect to the longitudinal axis 38.

[0023] Fig. 2 shows the in Fig. 1 The section of component 3 designated II, corresponding to the exemplary embodiment, is shown in a detailed schematic representation. The injector 7 and the connection 16A of the high-pressure outlet 16 are selected here as examples for the injectors 7 to 10 and the connection stubs 16A to 19A of the high-pressure outlets 16 to 19. The injector 7 has an inlet 45 which, when mounted in a mounting direction 46 along the mounting axis 40, engages in the bore 33 ( Fig. 1 The injector 7 is inserted into the connection fitting 16A. In the assembled state, the injector 7 is held against a cylinder head (not shown) opposite to the assembly direction 46 by a retainer 47, which is supported on an underside 48 of the connection fitting 16A. This positions and holds the injector 7 along the assembly axis 40. In principle, there are also rotational degrees of freedom in and against an (arbitrarily) selected direction of rotation 49. These rotational degrees of freedom are also restricted in the assembled state. For this purpose, an orientation element 50 of the injector 7 engages in a recess 51 of the connection fitting 16A, which is provided on an outer surface 52 of the connection fitting 16A. The recess 51 transitions into the outer surface 52 at an edge 53.Furthermore, the recess 51 is open towards the underside 48 of the connecting piece 16A, so that during assembly the orientation element 50 can be inserted into the recess 51 of the connecting piece 16A coaxially with the assembly axis 40 in the assembly direction 46. In order to reduce or completely avoid any play that is possible in the direction of rotation 49, lateral lugs 54, 55 are formed on the orientation element 50 in this embodiment.

[0024] The design of component 3 and its functionality in the embodiment of the invention are described below, also with reference to the Fig. 3, 4 as well as 5A and 5B described further. Fig. 3 shows a detail of the 16A connection fitting in Fig. 2 Component 3 shown, according to the exemplary embodiment. Fig. 4 shows a section along the in Fig. 2 The section line marked IV through the recess 51 of the connecting nozzle 16A (right side) is shown in comparison to another conceivable post-processing (left side) to illustrate the embodiment of the invention in a schematic representation.

[0025] The recess 51 is provided with a first side surface 56 and a second side surface 57. To restrict the rotational degree of freedom of the injection valve 7 relative to the component 3 in the direction of rotation 49, contact occurs between the nose 54 and the first side surface 46. Similarly, to restrict the rotational degree of freedom opposite to the direction of rotation 49, contact occurs between the nose 55 and the second side surface 57. A predetermined side height 58, which is specified in the Fig. 3 schematically depicted, is required to enable reliable contact between the noses 54, 55 and the side surfaces 56, 57. Starting from the in Fig. 3 In the depicted recess 51, the edge 53 is machined, as shown in Fig. 4 This illustrates the point.

[0026] Here, the right side of the Fig. 4 The processing of edge 53 according to a possible embodiment of the invention. Edge 53 is processed in such a way that the side height 58 is ensured at least on the first side surface 56 and on the second side surface 57. On the left side of the Fig. 4 However, a situation is shown in which a certain edge height 59 is realized, which does not correspond to the proposed invention.

[0027] Fig. 5A shows a schematic, excerpted representation of the connection stub 16A of the in Fig. 1 The component shown illustrates a possible embodiment of the invention, as it may be provided in the section designated II. Since the specified side height 58 is realized on both the first side surface 56 and the second side surface 57, a variable edge height 60 results along the extent of the edge 53.

[0028] Fig. 5B shows a schematic, excerpted representation of the connection fitting 19A, which is chosen here as an example of another connection fitting 19A, which is in Fig. 1 The component shown in the section labeled III illustrates a possible embodiment of the invention. For example, during manufacturing, particularly forging, a tolerance-related deviation may occur, where more material is provided at the connecting nozzle 19A than at the connecting nozzle 16A. This situation is shown in the Fig. 4 This is illustrated on the right side by means of a dashed line 61. For comparison, the following is shown on the left side: Fig. 4 A situation with more material is also illustrated by a dashed line 62, although the result obtained does not correspond to the invention. A recess 51' is provided on the outer surface 52' of the connecting piece 19A, which transitions into the outer surface 52' at an edge 53'. A first side surface 56' and a second side surface 57' are again realized with the predetermined side height 58. This results in a variable edge height 60'. Since the predetermined side height 58 is realized as the target dimension, the edge 53' on the connecting piece 19A differs from the edge 53 on the connecting piece 16A. In particular, the variable edge heights 60, 60' deviate from each other along the extensions of the edges 53, 53' (at corresponding points).

[0029] As it appears on the left side of the Fig. 4 As shown, specifying a certain edge height 59 results in the situation that side heights 63 and 63' are different from each other. Furthermore, when considering, for example, the Fig. 5A It is clear that specifying a certain edge height 59 along a course of the edge, for example in a direction 64, would lead to a side height increasing along the direction 64.

[0030] Thus, the one on the left side of the Fig. 4 The illustrated measure of specifying a certain edge height 59 would result in both the side height of the side surfaces on a single connection spigot being variable, for example along direction 64, and differences in side height occurring between different connection spigots.

[0031] For example, in one possible embodiment of the invention, the specified side height 58 can be at least approximately equal to the minimum height for the side surfaces 56, 57. As described in the Fig. 4 As shown on the left, in a non-inventive embodiment, particularly after post-processing of an edge 65, 66, the resulting side height 63 may be significantly less than the minimum height, while in another case the side height 63' may significantly exceed the minimum height. Such deviations could also occur along direction 64 on the side surfaces of a single connecting piece.

[0032] Thus, the proposed post-processing ensures the function of the recess 51 on the connecting piece 16A, since the side surfaces 56, 57, which serve as lateral stop surfaces, are always present at a sufficient height. The machining of the edge 53, or deburring, can then be defined, taking into account the variations in the external geometry of the connecting piece 16A and the manufacturing tolerances, in such a way that the minimum required side height is always present. The resulting change in the size, in particular the edge height 60, of the machined edge 53 has no influence on its function.

[0033] The post-processing of edge 53 can be carried out with a suitable tool angle.

[0034] Edge 53 can also have a different edge geometry. For example, edge 53 can also be designed as a rounded edge 53.

[0035] An inner edge line 70, which runs between the first side surface 56 or the second side surface 57 and the edge 53, can then be continuously spaced from a base 71 of the recess 51 according to the specified side height 58 in the proposed design.

[0036] Thus, after forging, the connecting piece 16A is post-processed such that at least one side surface 56, 57 of the recess 51 of the connecting piece 16A, on which contact between the orientation element 50 of the injection valve 7 and the connecting piece 16A is enabled in the assembled state, is designed with a predetermined side height 58. This applies accordingly to the other connecting pieces 16A to 19A.

[0037] The invention is not limited to the described embodiments. However, the invention is limited by the following claims.

Claims

1. Component (3), in particular fluid distributor (2), for an injection system (1) for mixture-compressing, spark-ignited internal combustion engines, which is used for metering a fluid under high pressure, having a main body (14) and at least one connection port (16A - 19A) which is formed on the main body (14) and serves for connecting an injection valve (7 - 10), wherein the injection valve (7 - 10) during assembly along an assembly axis (40 - 43) is able to be introduced into a receptacle chamber (27 - 30) of the connection port (16A - 19A), wherein at least the main body (14) and the connection port (16A - 19A) are formed by single- or multi-stage forging and wherein formed on an external side (52, 52') of the connection port (16A - 19A) is a recess (51, 51') into which, in the assembled state, an orientation element (50) of the injection valve (7 - 10) engages to limit a degree of freedom of rotation of the injection valve (7 - 10) about the assembly axis (40 - 43), wherein the connection port (16A - 19A) is post-machined after forging in such a way that at least one lateral face (56, 57, 56', 57') of the recess (51, 51') of the connection port (16A - 19A), on which in the assembled state, for limiting a degree of freedom of rotation in a selected direction of rotation (49) about the assembly axis (40 - 43), contact between the orientation element (50) of the injection valve (7 - 10) and the connection port (16A - 19A) is enabled, is designed at least approximately with a predefined lateral height (58), characterized in that the recess (51) on one edge (53) transitions into the external side (52) of the connection port (16A), in that the edge (53) is formed as a machined edge (53) and in that the machining of the edge (53) is carried out in such a way that the lateral face (56), or a further lateral face (57), respectively, is designed at least approximately with the predefined lateral height (58), wherein the machined edge (53) is formed as an at least partially bevelled and / or at least partially radiused edge (53).

2. Component according to Claim 1, characterized in that the further lateral face (57) of the recess (51) of the connection port (16A), which faces the lateral face (56) of the recess (51) and on which, in the assembled state, for limiting a degree of freedom of rotation counter to the selected direction of rotation (49), contact between the orientation element (50) of the injection valve (7) and the connection port (16A) is enabled, is designed at least approximately with the predefined lateral height (58).

3. Component according to Claim 1 or 2, characterized in that the machined edge (53) is formed along an edge profile with an at least partially varying edge geometry, in particular with an at least partially varying edge height (60).

4. Component according to one of Claims 1 to 3, characterized in that the post-machining of the connection port (16A) after forging is carried out in such a way that the edge geometry, in particular the edge height (60), is changed during post-machining in such a way that the lateral face (56), or the further lateral face (57), respectively, is or are designed at least approximately with the predefined lateral height (58).

5. Component according to one of Claims 1 to 4, characterized in that the connection port (16A) is post-machined after forging in such a way that the recess (51) and the edge (53) are formed conjointly using a combined tool geometry.

6. Injection system (1) for mixture-compressing, spark-ignited internal combustion engines, which is used for injecting a fluid, which is fuel, in particular gasoline and / or ethanol, and / or a mixture with fuel, having at least one component (3) according to one of Claims 1 to 5.

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