JP2012167681A - Fuel distributor for fuel injection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel distributor which attains an effective reduction of noise generating when an injection valve is controlled.SOLUTION: A cover (15) is made of plastics which break noise, the fuel distributor has at least one fixed hole (29), an attenuation member (31) is disposed between at least this one fixed hole (29) and a fixed screw (27), the attenuation member (31) secures acoustic separation between the fuel distributor, the fixed screw (27), and a joining partner (33) both in an axial direction and in a radial direction, the attenuation member (31) has a cylindrical sleeve (35) and two disks (39), and at least the one disk (39) is made of steel wool which is compressed in a disk-shaped form.

Description

  The present invention is a fuel distributor for a fuel injection device, comprising a fuel distribution member and at least two injection valves, the injection valves being fluidly coupled to the fuel distribution member, and The present invention relates to a fuel distribution member and an injection valve cover.

  A fuel distributor of this type is known, for example, from German Offenlegungsschrift 19546441. A known fuel distribution member has a problem of supplying fuel to an injection valve. For this purpose, the fuel distribution member has one connection pipe piece for each injection valve, and the injection valve is fixed to the connection pipe piece so as to be disengageable or not disengageable. For example, it is known to fix an injection valve to a connecting pipe piece by welding. As an alternative, it is also possible to fix the injection valve to the connecting pipe piece by means of a detachable or non-detachable snap joint.

  In order to fix the injection valve with respect to its position, in the fuel distributor known from the above-mentioned German Offenlegungsschrift 19546441, it is known that both the fuel distribution member and the injection valve are surrounded by a cover. is there. In this case, glass fiber reinforced plastic is used.

German Patent Application Publication No. 19546441

  The object of the present invention is to avoid the known drawbacks.

  In order to solve this problem, in the present invention, the cover is made of a plastic that blocks noise, and the fuel distributor has at least one fixing hole, and between the at least one fixing hole and the fixing screw. The damping member is arranged in a cylindrical shape so as to guarantee an acoustic separation between the fuel distributor, the fixing screw and the joining partner both axially and radially. Sleeve and two discs, at least one disc being made of steel wool compressed into a disc shape.

  By selecting a plastic that blocks noise, the noise generated during control of the injection valve can be effectively reduced. This is particularly important when idling internal combustion engines. This is because the new internal combustion engine is so quiet that the switching noise of the injection valve is heard today as a quiet “click” sound, and this “click” sound detracts from the acoustic impression of the internal combustion engine.

  After all, the use of plastics to block out noise significantly improves the quiet operation of the internal combustion engine, especially in idling operations which are important for evaluation. The reduction in generated noise is particularly effective in the frequency range from 4 kHz to 16 kHz, so that the noise reduction obtained by the cover of the present invention is perceived by humans.

  Since the configuration and structure of the fuel distributor according to the present invention remains almost unchanged, the present invention can be implemented without significant excess expenditure. This is particularly important in injection devices manufactured in mass production.

  In particular, polyamide, polybutylene terephthalate or polyphenyl sulfide has proven to be an advantageous plastic.

  It is further advantageous if the cover is made of an elastic foam material. This is because such a foam has a very good noise barrier property. In particular, it has been found that it is particularly effective to use an open-cell foam filled with a filling material having a high specific gravity. In this case, the invention is not limited to open-cell foams, but can also be realized advantageously with closed-cell foams.

Further in connection with the present invention, it has been found advantageous to add a filler, preferably a filler having a high specific gravity, to the cover. In this case, the specific gravity range in which the filler is preferably located is related to the ambient conditions. This is because in order to obtain optimum results, the sound source and the shielding material must be combined in all vibration phenomena. Testing has shown that plastics with a specific gravity greater than 1.0 g / cm ³ have a sufficient damping effect. It has also been found that plastics having a specific gravity of 1.4 g / cm ³ are particularly advantageous. However, the present invention is not limited to these specific gravities.

  Barium sulfate and iron oxide have been found to be advantageous fillers.

  The cover of the fuel distributor according to the invention can advantageously be produced by plastic injection molding. Alternatively in this case, the cover is injection molded directly surrounding the fuel distribution member and the injection valve, or the cover is made from two shells, the two shells being connected to the fuel distribution member and at least 2 It is possible to surround one injection valve and fix it at this position. Which one of the configurations is preferred in each case is related to other ambient conditions and is determined in each case.

  In order to further improve the noise isolation, a damping member is arranged in the fixing hole of the fuel distributor, which damping member is located between the cover, the fixing screw and the joining partner (for example the cylinder head or the intake pipe of the internal combustion engine). Ensures acoustic separation in both axial and radial directions.

  In this case, it has been found that it is advantageous if the damping member consists of a cylindrical sleeve and two disks. In this case, the sleeve is preferably made of a shape-stable material, whereas the disc is made of a material with good damping properties. The disc can be made in one piece, for example from rubber. As an alternative, the disc can also be made from metal, in which case it has proved to be very advantageous if at least one of the two discs consists of steel wool compressed into a disc-like shape. Steel wool compressed into a predetermined shape provides the desired acoustic separation between the fuel distributor and the joining partner, so that propagation of injection valve switching noise is also effectively prevented in this position.

  After all, the fuel distributor according to the present invention makes it possible to sufficiently suppress the switching noise of the injection valve, and yet another cover or means for blocking the noise is no longer necessary.

1 is a cross-sectional view of a first embodiment of a fuel distributor according to the present invention. FIG. 6 is a cross-sectional view of a second embodiment of the fuel distributor according to the present invention. It is an isometric view of a fixing hole provided with a damping member. 1 is a cross-sectional view of an embodiment of a damping member according to the present invention. FIG. 5 is a cross-sectional view of an embodiment of the damping member according to the present invention different from FIG. 4.

  In the following, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a cross-sectional view of a fuel distributor according to the present invention. This fuel distributor comprises a tubular fuel distribution member 1. From this fuel distribution member 1, a plurality of connecting pipe pieces 3, which are visible only in FIG. 1, branch off. An injection valve 5 is fixed to each connecting pipe piece 3 in a liquid-tight manner. This may be done, for example, by a weld seam 7 or by a dissociable or non-dissociable joint (see FIG. 2).

  The fuel supply of the injection valve 5 is performed via the inflow portion 9 of the fuel distribution member 1, the fuel distribution member 1, and the connecting pipe piece 3. FIG. 1 shows an electrical contact 11.

  The electrical contact 11 is electrically connected to the connection bushing 13 via a cable or another conductor. Thereby, simultaneously with fixing of the injection valve 5 in the connection pipe piece 3, the injection valve 5 is electrically connected and all the injection valves 5 of the fuel distributor are inserted into the connection bushes 13 by inserting connectors. It is possible to connect to a control device. Both the fuel distribution member 1 and the injection valve 5 are surrounded by a cover 15, which is made of plastic that blocks noise.

  As shown in FIG. 1, the cover 15 may be injection molded surrounding the fuel distribution member 1 and the injection valve 5. In this case, the fuel distributor cannot be disassembled into individual members. This provides an advantage with regard to sealing against environmental influences such as moisture and reduces the number of components or groups.

  A suitable plastic for the cover 15 is selected in relation to the desired application and the surrounding conditions prevailing in the cover 15. Please refer to the beginning of the description for various plastics that have proven to be suitable for testing.

  FIG. 2 shows an alternative embodiment of the fuel distributor according to the invention, in which a significant difference from the first embodiment is that the injection valve is releasably coupled to the connecting tube piece 3. It is in that it has been. This connection is made by a U-shaped clip 17, which has a C-shaped profile. This C-shaped profile cooperates with the corresponding projection 19 of the connecting tube piece 3 and the injection valve 5, thereby forming a shape-connecting joint. In order to obtain the required seal, a seal ring, in particular an O-ring 19 is additionally provided.

  Since the connection between the connecting pipe piece 3 and the injection valve 5 can be dissociated by the clip 17 being taken out in a direction perpendicular to the drawing plane, the injection valve 5 can be subsequently drawn downward as viewed in FIG. it can. Obviously, the cover 15 must have a notch 25 into which the clip 17 can be introduced and withdrawn.

  In this embodiment, an electrical contact is also realized by the signal line 21 and the connector 23. This means that in the second embodiment shown in FIG. 2, the individual injectors 5 can be replaced if they no longer operate in a satisfactory manner.

  Refer to the description at the beginning of the specification for the material for manufacturing the cover 15.

  FIG. 3 shows an isometric view of the detailed structure of the fuel distributor according to the present invention. FIG. 3 shows a fixing screw 27 inserted through the fixing hole 29 of the fuel distributor.

  A damping member 31 according to the present invention is arranged between the fixing screw 27 and the fixing hole 29, and this damping member 31 is a joining partner of the fuel distributor such as a cylinder head or an intake pipe (not shown). Prevents transmission of solid-borne sound to the.

  FIG. 4 shows a cross-sectional view of a first embodiment of the damping member 31 according to the invention. In this case, the reference numeral 33 indicates the upper edge of the joining partner 33 to which the fuel distributor is fixed by means of a fixing screw 27 (which can be, for example, a cylinder head or an intake pipe of an internal combustion engine).

  A sleeve 35 and a washer 37 are disposed between the joining partner 33 and the head of the fixing screw 27. The sleeve 35 may be made of a steel pipe, for example, and is set to a length that prevents unacceptable compression of the damping member 31. In addition to the components described above, the damping member has two discs 39, which are produced, for example, from compressed steel wool. The disk 39 positions the fixing hole 29 of the fuel distributor with respect to the joining partner 33 both axially and radially. In this case, no solid-borne sound is transmitted from the fuel distributor to the joining partner 33 due to the good damping characteristics of the disk 39 made of compressed steel wool. Thereby, the propagation of the solid propagation sound from the fuel distributor to the joining partner 33 is effectively prevented. The disk 39 has extremely high heat resistance, is not easily affected by fuel, and is not easily aged, so that it is infinitely effective over the entire useful life of the internal combustion engine.

  An alternative embodiment is shown in FIG. In this embodiment as well, a metal sleeve 35 is provided, which guarantees a minimum distance between the head of the fixing screw 27 and the joining partner 33. The damping member 31 formed as a rubber molding member between the fixing hole 29 and the sleeve 35 has two disks 39, which are connected to each other by a hose-shaped section 41. By the discs 39 being connected to each other by the hose-like section 41, the rubber molded member can be constructed in one piece, which facilitates assembly and storage.

  DESCRIPTION OF SYMBOLS 1 Fuel distribution member, 3 Connection pipe piece, 5 Injection valve, 7 Welding seam, 9 Inflow part, 11 Contact, 13 Connection bushing, 15 Cover, 17 Clip, 19 Protruding part, 21 Signal line, 23 Connector, 27 Fixing screw, 29 fixing hole, 31 damping member, 33 joining partner, 35 sleeve, 37 washer, 39 disc, 41 hose section

Claims (2)

A fuel distributor for a fuel injection device, wherein a fuel distribution member (1) and at least two injection valves (5) are provided, and these injection valves (5) are liquid-tight with the fuel distribution member (1). In addition, a fuel distribution member (1) and a cover (15) of the injection valve (5) are provided.
The cover (15) is made of plastic that blocks noise,
The fuel distributor has at least one fixing hole (29), and a damping member (31) is arranged between the at least one fixing hole (29) and the fixing screw (27). A member (31) is adapted to ensure acoustical separation between the fuel distributor, the fixing screw (27) and the joining partner (33) both axially and radially;
The damping member (31) has a cylindrical sleeve (35) and two discs (39);
A fuel distributor for a fuel injection device, characterized in that at least one disc (39) consists of steel wool compressed into a disc-like shape.   2. The fuel distributor according to claim 1, wherein if only one disk (39) is made of compressed steel wool, the second disk (39) is made of rubber.

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