DE102008044165A1 - Fuel distributor - Google Patents

Abstract

The present invention relates to a fuel distributor (22) for an internal combustion engine having a housing and an injection valve (24) connected thereto. The housing has at least one fastening section (30) with which the fuel distributor (22) can be fastened to a mounting structure (32) of the internal combustion engine (10). Between the attachment portion (30) and the mounting structure (32) of the internal combustion engine (10) at least one damping element (50) is arranged, which comprises at least one vibration-damping layer (54).

Description

State of the art

modern Internal combustion engines for motor vehicles with gasoline direct injection include a fuel rail that serves as a common fuel tank is used for high pressure injectors. The high pressure is generated by a high-pressure pump, the fuel distributor connected. The fuel feeder becomes vibrations when driving stimulated in the audible frequency range. This happens on the one hand due to pulsations and structure-borne noise as a result of the operation the high-pressure injectors arranged on the fuel feeder, on the other hand, due to pulsations caused by the transient Promotion of the high-pressure pump can be caused.

From the DE 10 2005 008 038 A1 For example, a fuel distributor for an internal combustion engine is known, in which a sound-absorbing casing of the fuel meter attenuates switching noises of the injection valves.

Disclosure of the invention

task The invention is a fuel dispenser in an internal combustion engine to develop so that the fuel feeder with low cost ensures quiet operation.

to Solution of the task is a fuel feeder with the Features of claim 1 and an internal combustion engine having the features proposed the sibling claim. For the invention Important features can also be found in the following description and in the drawings, the features being both alone as well as in different combinations for the invention can be important without being explicit on each one is pointed out. Advantageous developments are also found in the subclaims.

According to the invention was Recognized that an audible, disturbing noise in the sense of airborne sound at a fuel feeder in two ways arise can: On the one hand, directly from the vibrating surface the fuel feeder airborne sound emitted. Second, over Screwing or fastening points on fasteners Structure-borne sound to a mounting structure of the internal combustion engine forwarded, resulting in further unwanted sound transmission and associated sound radiation leads, under Circumstances to the interior of the vehicle. The cultivation structure is usually a cylinder head; however, it can also be a connection of the fuel meter via spacers or over other connecting elements take place.

On the attachment (screw) of the fuel meter act during of driving high static forces and dynamic alternating forces. It may face a certain relative movement of the fuel meter the cylinder head in operation at the respective operating point not exceeded become. Due to these functional and strength requirements so far the fuel feeder sits relatively stiff on the mounting structure (eg cylinder head) and therefore largely transmits undamped vibrations.

By the damping element according to the invention be vibrations (pulsations) in the fuel rail generated or transmitted via the fuel rail be steamed. The necessary stability remains however obtained, d. H. the relatively rigid connection of the fuel meter is maintained despite the damping element. The elasticity the attachment of the fuel meter only increases lightweight and continues to meet all functional requirements (low relative movement of the fuel meter and the associated Injectors) and strength requirements (load of mounting bolts). At the same time, acoustic, functional and strength requirements, resulting from a fuel meter design met.

The The present invention thus leads to a vibration technology Decoupling and thus to a noise reduction. The vibration amplitudes (vibration load), the on the fuel feeder and on the connected components act, such. B. pressure sensor and connector are lowered. The Structure-borne sound excitation of the internal combustion engine on the Fuel feeder is reduced by the decoupling and the from the fuel meter directly radiated noise are due to the increased damping due to the Damping elements reduced.

Another advantage is a lower vibration load of the fuel meter, which increases its life. The reduction in structure-borne sound transmission also reduces airborne radiation emitted by the structure-borne sound from the mounting structure (for example, a housing of the internal combustion engine). In addition, the transmission of structure-borne noise is reduced to the body via other components. All of these measures also reduce the noise of the fuel injection system perceived as disturbing by occupants of the motor vehicle. The introduction of the damping elements in the region of the mounting portions of the fuel meter during assembly is easy to implement, which has a favorable effect on the cost. In addition, the damping element requires practically no kei NEN additional space.

additionally It is proposed that the attachment section at least one Has bore into which a mounting screw is inserted, and that between the screw head of the mounting screw and the mounting portion or the mounting structure of the internal combustion engine, at least one damping element arranged with at least one vibration damping layer is. This takes into account that in addition to a bearing surface the attachment portion on the mounting structure of the internal combustion engine Vibrations also transferred via the mounting screws can be. By the vibration-damping Layer in the area of the screw heads this is prevented or at least greatly reduced.

Especially It is advantageous if the vibration-damping layer a viscoelastic material. Called viscoelastic one polymers (large-molecular elastic plastics such as for example, polyurethanes, elastomers, plastomers, thermoplastics or silicones) with special elastic properties. The properties are outward in the way, as would the elasticity solid body connect with liquid-like behavior. Under dynamic stress becomes part of the deformation work (eg vibrational energy) dissipated from the viscoelastic material (transformed). Similar effects work under normal load, in particular under pressure, on the sheet. In this case, the viscoelastic Layer compresses and deviates in sheet metal direction, which in turn to Dissipation due to material deformation in the viscoelastic Layer leads. It is also a transferred Structure-borne sound efficiency through the viscoelastic Material damping partly dissipated and also absorbed. The dissipation of body sound energy leads in any case to a damping of vibration modes of the Kraftstoffzuteilers and to a reduction of all body sound components, the transferred through this layer from the fuel meter in the mounting structure become. It therefore becomes the sound power through the transmission path reduced. This property corresponds to an acoustic decoupling or insulation of the fuel meter.

Farther it is proposed that the damping element at least has a metallic sheet, and that at least on one side of the Sheet metal, the vibration damping layer is arranged. The damping element (so-called "sandwich" -, laminated, silent or "compound" sheet) preferably disc-shaped and serves as a base for the attachment section of the fuel meter, which is attached to the mounting structure. On the metallic sheet a thin viscoelastic layer is laminated. The Metallic sheet metal has a stabilizing effect, so that the elasticity the attachment of the fuel meter by the viscoelastic Layer only slightly increases and all functional requirements (rigid attachment) and strength requirements (load of Mounting screws) can be fulfilled anyway. The use such a damping element leads in this case at the attachment points of the fuel meter to a damping the fuel distributor vibrations. In addition, the Structure-borne sound transmission into the growing structure, For example, a cylinder head of the internal combustion engine, clearly reduced. As a result of these two effects, a sound radiation or Sound transmission from the fuel meter and the mounting structure reduced, and the vibration load of the affected components is lowered. The production of the damping elements takes place essentially by trimming just executed Sheets on which the viscoelastic layer is already laminated is. Since the damping element from inexpensive producible Material exists and no costly production costs incurred the invention is inexpensive and effective.

additional For this purpose, it is proposed that the damping element at least has two metallic sheets, between which the vibration damping Layer is arranged (sandwich panel). Also this damping element is preferably disc-shaped and acts as Pad between the mounting portion of the fuel meter and the mounting structure of the internal combustion engine. While in the first-described embodiment of the damping element the viscoelastic properties were increased are in the second embodiment through the use of two metallic Sheet metal increases the stabilizing properties of the attachment. In terms of manufacturing technology, here is the viscoelastic layer between laminated to the two sheets. This damping element is also inexpensive to produce and effective.

Further it is proposed that the damping element at least a metallic sheet comprising, on both sides, a vibration damping Layer has. In a bilateral lamination of the viscoelastic Layer on the sheet are the vibration-damping Properties further increased. The viscoelastic effect is effective Layer after mounting the damping element between Fuel feeder and mounting structure as a sandwich between Support surface and metal layer of the damping element and / or between fuel feeder and metal layer of the substrate.

It is also proposed that the vibration-damping layer at least on one side has a profiling or micro-profiling, for example in the form of knobs or ribs. As a result, the vibration damping Effect further increased.

Brief description of the drawings

following Be with reference to figures embodiments of the invention explained in more detail. Show it:

1 a schematic diagram of an internal combustion engine with a fuel rail;

2 a schematic detail view of the fuel meter 1 ;

3 a first embodiment of a damping element according to the invention;

4 A second embodiment of the damping element according to the invention;

5 a third embodiment of the damping element according to the invention;

6 A fourth embodiment of the damping element according to the invention;

7 a schematic representation of a possibility of attachment of the fuel meter 1 or 2 ;

8th a cut view similar to 2 an alternative embodiment of a fuel meter; and

9 a cut view similar to 2 a yet alternative embodiment of a fuel meter.

embodiments the invention

An internal combustion engine carries in 1 Overall, the reference number 10 , It includes a fuel tank 12 from which a prefeed pump 14 Fuel in a low pressure line 16 promotes. The pressure in the low pressure line 16 is by a pressure control or pressure control valve 18 set. The low pressure line 16 leads to a high pressure fuel pump 20 , The high pressure fuel pump 20 is mechanically from the internal combustion engine 10 driven. It compresses the fuel to a very high pressure and delivers it in a high-pressure line 21 to a fuel feeder 22 whose construction is in 2 will be described in more detail. At these are several high pressure injectors (injectors) 24 connected to the fuel under high pressure in them directly associated combustion chambers 26 inject. The operation of the internal combustion engine 10 is controlled by a control device 28 controlled and regulated.

2 shows the fuel feeder 22 in a schematic representation. He has fastening sections on both sides 30 on to him on a cultivation structure 32 (eg a cylinder head) of the internal combustion engine 10 to fix. Between the attachment sections 30 and the growing structure 32 is in each case a damping element 50 arranged, which dampens vibrations in the audible range.

The fuel feeder 22 is excited during operation to oscillations in the audible frequency range. This happens on the one hand by pulsations and structure-borne noise as a result of the operation of the fuel meter 22 located high-pressure injectors 24 on the other hand due to pulsations caused by the transient delivery of the high-pressure fuel pump 20 be caused. An audible noise in the sense of airborne sound is mainly due to two ways: Firstly, directly from the vibrating surface of the fuel meter 22 Airborne sound emitted. Second, about the attachment sections 30 Structure-borne sound to the cultivation structure 32 forwarded, which leads to a further unwanted sound transmission and the associated sound radiation, possibly to the interior of the vehicle.

Function and requirements for the operating life of the fuel meter 22 However, some requirements for the attachment of the fuel meter 22 , For example, high static forces and dynamic alternating forces act on a fastening. In addition, allows a certain relative movement of the fuel meter 22 opposite the cylinder head 32 during operation are not exceeded. Due to these functional and strength requirements, the fuel meter must 22 relatively stiff on the cultivation structure 32 to sit. The damping elements used here 50 with, for example, thin viscoelastic layers, due to their high material damping, a reduction of the vibration properties and the structure-borne noise transmission, without making the rigid connection too flexible. The stiff position of the fuel meter 22 on the cultivation structure 32 is essentially retained.

In the internal combustion engine shown here 10 Therefore, the damping element 50 according to 3 with a vibration-damping layer 54 to reduce the transmission of sound between the attachment portion 30 and the growing structure 32 the internal combustion engine 10 used. The damping element 50 includes a metallic sheet 52 and a preferably laminated, viscoelastic layer applied thereon 54 (so-called "sandwich" -, laminated, silent or "compound" sheet), so that a disc-shaped damping element 50 results. In addition, the damping element 50 Have holes for mounting screws.

Here is the viscoelastic layer 54 just thin on the sheet 52 applied. The present embodiment is thereby quite stiff. In addition, the vibration-damping layer 54 have a profiling or micro-profiling, for example in the form of knobs or ribs, which further enhances the damping properties.

4 shows a structure of a second embodiment of the disc-shaped damping element 50 , To 3 identical or functionally equivalent components are here and below identified by the same reference numerals and will not be explained again.

The damping element 50 from 4 has two metal sheets arranged parallel to one another 52 on, between which the vibration-damping layer 54 is laminated. The sheets 52 may be made in a non-illustrated embodiment of different thickness and / or of a different material. The present embodiment is particularly stiff. In an embodiment, not shown, the damping element and more than two sheets 52 and therefore more than a viscoelastic layer 54 exhibit.

In 5 has the damping element 50 a single metallic sheet 52 on both sides with a vibration-damping layer 54 is coated from viscoelastic material, for example by lamination. The thickness of the viscoelastic material 54 can be different. In an embodiment not shown, the damping element 50 more than a sheet 52 and thus more than two vibration-damping layers 54 exhibit.

6 shows a structure of the disc-shaped damping element 50 in a fourth embodiment. In the embodiment of 6 are the embodiments of the 3 and 4 combined together. The damping element 50 has two metal sheets arranged parallel to one another 52 on, between which a first vibration-damping layer 54 coated from a viscoelastic material, preferably laminated. Additionally is in 6 the upper side of the damping element 50 from the outside with a second vibration-damping layer 54 coated from viscoelastic material, which is preferably laminated. Again, the thickness of the sheets 52 and / or the vibration damping layers 54 be different and the damping element 50 can have more than two sheets 52 and thus more than two vibration-damping layers 54 exhibit.

The exemplary embodiments show that the arrangement of the individual layers (sheet metal 52 and vibration-damping layer 54 ) of the damping element 50 may be very specific to the specific application.

7 shows a schematic representation of a possibility of attachment of the fuel meter 22 out 1 or 2 using mounting screws using the damping element 50 , As in addition to the bearing surfaces of the attachment sections 30 of the fuel meter 22 also the present to the attachment sections 30 If the associated screw mounts can transmit vibrations via the corresponding mounting screws, the mounting screws can also be included in the damping concept. In principle, all four (in 3 to 6 ) embodiments are used in the field of mounting screws. In the individual case, a selection should be made according to the requirements for stability and damping or decoupling capacity.

The left side in 7 shows an exploded view of a possible attachment of the fuel meter 22 , The figure shows a mounting screw 60 into a hole (without reference numeral) of a screw holder 62 of the fuel meter 22 (not shown here) is introduced. On both sides of the screw holder 62 the shaft includes the mounting screw 60 in each case an annular disk-shaped damping element 50 , On the side facing away from the screw head has the mounting screw 60 a screw fixation 64 made of plastic and a spacer sleeve 66 on.

The right side in 7 shows the bolted device.

Will the damping element 50 between the fuel rail 22 and the growing structure 32 and additionally in the area of mounting screws 60 Used, a complete insulation without metallic contacts between the fuel rail 22 and the growing structure 32 achieved, resulting in a maximum reduction in structure-borne sound transmission through the mounting screws 60 in the cultivation structure 32 leads.

8th shows an alternative connection of the high pressure injectors 24 to the fuel feeder 22 , The fuel feeder 22 has a connection section 68 (so-called "rail cup") on which the injection valves 24 receives radially. The injectors 24 lie on the fuel feeder 22 not at an axial stop, so they are axially so largely from the fuel rail 22 mechanically decoupled. Instead, the injectors 24 by the force coming out of the fuel rail 22 prevailing pressure results, pressed against the cylinder head and thereby fixed (English "non suspended rail "). The injectors 24 are radially in the terminal section via a 0-ring (not shown) 68 sealed and fixed. One in the injectors 24 generated structure-borne sound is therefore mainly on hydraulic way to the fuel meter 22 transmitted, and its forwarding can then via the damping elements 50 at the attachment sections 30 of the fuel meter 22 be reduced.

9 shows another alternative connection of the high-pressure injectors 24 to the fuel feeder 22 , The fuel feeder 22 also has the connection section here 68 (so-called "rail cup") on which the injection valves 24 receives. The injectors 24 However, lie positively and non-positively on or in the connection section 68 ("suspended rail"), wherein the injection valves 24 no axial contact with the mounting structure 32 (Cylinder head) have. Should the fuel feeder 22 can not be mounted close enough to the cylinder head for reasons of space, in this case, the connection section 68 via a short line (not shown) with the fuel rail 22 get connected. Here is next to that in the injectors 24 Hydro sound also produced a structure-borne noise on the fuel rail 22 transferred so that the damping elements 50 at the attachment sections 30 of the fuel meter 22 are particularly useful.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102005008038 A1 [0002]

Claims (10)

Fuel feeder ( 22 ) for an internal combustion engine ( 10 ), with a housing, wherein the fuel feeder ( 22 ) with at least one injection valve ( 24 ) is connectable and wherein the housing at least one attachment portion ( 30 ), with which the fuel feeder ( 22 ) on a growing structure ( 32 ) of the internal combustion engine ( 10 ), characterized in that at the attachment portion ( 30 ) to the growing structure ( 32 ) of the internal combustion engine ( 10 ) at least one damping element ( 50 ), the at least one vibration-damping layer ( 54 ). Fuel feeder ( 22 ) according to claim 1, characterized in that the fastening portion ( 30 ) has at least one bore into which a mounting screw ( 60 ) is inserted, and that the damping element ( 50 ) between the screw head of the mounting screw ( 60 ) and the attachment section ( 30 ) or the growing structure ( 32 ) of the internal combustion engine ( 10 ) is arranged. Fuel feeder ( 22 ) according to claim 1 or 2, characterized in that the vibration-damping layer ( 54 ) comprises a viscoelastic material. Fuel feeder ( 22 ) according to one of the preceding claims, characterized in that the damping element ( 50 ) at least one metallic sheet ( 52 ), and that at least on one side, preferably on both sides of the sheet ( 52 ) the vibration damping layer ( 54 ) is arranged. Fuel feeder ( 22 ) according to claim 4, characterized in that the damping element ( 50 ) at least two metallic sheets ( 52 ), between which a vibration-damping layer ( 54 ) is arranged. Fuel feeder ( 22 ) according to one of claims 4 or 5, characterized in that the damping element ( 50 ) at least one metallic sheet ( 52 ), which on both sides a vibration-damping layer ( 54 ) having. Fuel feeder ( 22 ) according to one of the preceding claims, characterized in that the vibration-damping layer ( 54 ) has a profiling or micro-profiling, in particular in the form of knobs, on at least one side. Fuel feeder ( 22 ) according to one of the preceding claims, characterized in that it has connection sections ( 68 ) for the injection valves connected to it ( 24 ) and is mechanically decoupled from these in at least one direction. Fuel feeder ( 22 ) according to one of claims 1 to 7, characterized in that it has connecting sections ( 68 ) for those with the fuel meter ( 22 ) connected injection valves ( 24 ) and is mechanically connected thereto. Internal combustion engine ( 10 ) with a fuel injection system, wherein the fuel injection system a fuel meter ( 22 ) with a housing and at least one associated with this injection valve ( 24 ) and wherein the housing has at least one attachment section ( 30 ), with which the fuel feeder ( 22 ) on a growing structure ( 32 ) of the internal combustion engine ( 10 ), characterized in that between the attachment portion ( 30 ) and the growing structure ( 32 ) of the internal combustion engine ( 10 ) at least one damping element ( 50 ) is arranged, the at least one vibration damping layer ( 54 ).