DE102018210023A1 - attenuator module - Google Patents

Abstract

The invention relates to a damper module (14) with a high-pressure fuel pump in a fuel injection system, the damper module (14) for damping pressure pulsations comprising a housing (20) with an additional volume. To create a damper module (14) that is simple in construction and inexpensive to produce is, the housing (20) of the damper module (14) from formed sheet metal parts (41-43) is formed.

Description

The invention relates to a damper module with a high-pressure fuel pump in a fuel injection system, the damper module comprising a housing with an additional volume for damping pressure pulsations.

State of the art

From the German published application DE 10 2015 202 992 A1 A low-pressure connection unit for a high-pressure pump in a fuel injection system, in particular in a common-rail injection system, is known, comprising a housing which forms at least one connection piece for connection to a housing part of the high-pressure pump, the connection piece being penetrated by a low-pressure channel, wherein An additional volume connected to the low-pressure channel for damping pressure pulsations is formed in the housing, the additional volume being able to be relieved via a relief channel which opens into the low pressure or into another low-pressure channel, the low-pressure channel having a nozzle-like cross-sectional constriction in the region of the mouth of the relief channel has. From the German published application DE 10 2016 219 247 A1 A pump element for a high-pressure pump, in particular for a high-pressure fuel pump in a common rail injection system, with a pump piston, is known, which is guided to move back and forth in a pump cylinder head and which is coupled to a tappet body at an end protruding from the pump cylinder head.

Disclosure of the invention

The object of the invention is to provide a damper module with a high-pressure fuel pump in a fuel injection system, the damper module comprising a housing with an additional volume for damping pressure pulsations, which is simple in construction and inexpensive to produce.

The object is achieved in a damper module with a high-pressure fuel pump in a fuel injection system, the damper module comprising a housing with an additional volume for damping pressure pulsations, in that the housing of the damper module is formed from formed sheet metal parts. This creates an inexpensive to produce external damper module that is advantageously combined with the high-pressure fuel pump.

A preferred exemplary embodiment of the damper module is characterized in that a low-pressure connection piece and a connection connection piece for connection to the high-pressure fuel pump are attached to the housing of the damper module. The two connecting pieces are designed as turned parts, for example. The low pressure connection piece is used to connect the damper module to a low pressure area. The connecting pieces can be easily attached to the formed sheet metal parts of the housing of the damper module. A connection between the connecting piece and the housing of the damper module is preferably made integrally. The integral connection between the connecting piece and the housing of the damper module is preferably produced by welding, but can also be produced by soldering, in particular brazing, if necessary.

Another preferred exemplary embodiment of the damper module is characterized in that the low-pressure connecting piece and the connecting connecting piece are designed as identical parts. The two connecting pieces are preferably designed as turned parts.

Another preferred exemplary embodiment of the damper module is characterized in that the damper module has a return and / or ventilation connection with a hydraulic resistor. The hydraulic resistance is designed as a throttle, for example. The hydraulic resistance enables the damper module to vent a low-pressure area, in particular a low-pressure circuit, of the fuel injection system. In addition, the hydraulic resistance, which is preferably designed as a throttle, advantageously ensures a constant return flow quantity in the return and / or vent connection.

Another preferred exemplary embodiment of the damper module is characterized in that the hydraulic resistance is integrated in a return and / or vent connection. The return and / or vent nozzle is also advantageously designed as a turned part. In terms of production technology, the hydraulic resistance can be integrated directly into the return and / or vent connection. However, the hydraulic resistance can also be formed in a separate additional body, which is arranged in the return and / or vent connection, is advantageously pressed into the return and / or vent connection.

Another preferred exemplary embodiment of the damper module is characterized in that the housing of the damper module comprises a housing base body which has the shape of a straight circular cylinder jacket. The Housing base body is simple and inexpensive to manufacture from a sheet metal material.

A further preferred exemplary embodiment of the damper module is characterized in that the basic housing body has through holes for fastening one or the low-pressure connecting piece, one or the return and / or venting piece and the connecting piece. For connection, the connecting pieces can simply be inserted into the through holes of the basic housing body and welded to the basic housing body in the through holes.

Another preferred exemplary embodiment of the damper module is characterized in that the basic housing body is closed by two outer shells. The outer shells can be produced inexpensively from a suitable sheet metal material.

Another preferred exemplary embodiment of the damper module is characterized in that the outer shells are designed as identical parts. The outer shells advantageously have essentially the shape of a circular disk with a bent peripheral edge. This further simplifies the manufacture of the housing of the damper module. The outer shells are advantageously integrally connected to the basic housing body, for example by welding.

The invention further relates to a housing, in particular a basic housing body, an outer shell, a low-pressure connection piece, a connection connection piece and / or a return and / or ventilation piece for a previously described damper module. The parts mentioned can be traded separately.

Further advantages, features and details of the invention emerge from the following description, in which various exemplary embodiments are described in detail with reference to the drawing.

list of figures

• 1 eine schematische Darstellung eines Kraftstoffeinspritzsystems mit einer Kraftstoffhochdruckpumpe und mit einem externen Dämpfermodul, das zwischen einem Niederdruckbereich des Kraftstoffeinspritzsystems und der Kraftstoffhochdruckpumpe angeordnet ist;
• 2 eine perspektivische Darstellung eines Ausführungsbeispiels des Dämpfermoduls aus 1;
• 3 eine Explosionsdarstellung des Dämpfermoduls aus 2;
• 4 das Dämpfermodul aus den 2 und 3 im Schnitt;
• 5 einen Anschlussstutzen des Dämpfermoduls aus den 2 bis 4 im Längsschnitt; und
• 6 einen Rücklauf- und/oder Entlüftungsstutzen des Dämpfermoduls aus den 2 bis 4 im Längsschnitt.

Show it:

• 1 a schematic representation of a fuel injection system with a high-pressure fuel pump and with an external damper module, which is arranged between a low-pressure region of the fuel injection system and the high-pressure fuel pump;
• 2 a perspective view of an embodiment of the damper module 1 ;
• 3 an exploded view of the damper module 2 ;
• 4 the damper module from the 2 and 3 on average;
• 5 a connecting piece of the damper module from the 2 to 4 in longitudinal section; and
• 6 a return and / or vent connection of the damper module from the 2 to 4 in longitudinal section.

Description of the embodiments

In 1 is a fuel injection system 1 of a motor vehicle shown schematically. The fuel injection system 1 is, for example, part of a fuel injection system of an air-compressing, self-igniting internal combustion engine with a low pressure area 12 , from which, for example via a prefeed pump, not shown, fuel from a fuel tank to a pump inlet 10 a high pressure fuel pump 2 is promoted. The high pressure fuel pump 2 is as a plug-in pump 3 with a pump element 4 executed. The pump element 4 is about a roller 6 driven by a drive cam of a drive shaft (not shown).

In the high pressure fuel pump 2 that have more than one pump element 4 can include, the fuel is subjected to high pressure. The high-pressure fuel passes through a pump outlet 9 the high pressure fuel pump 2 in a high pressure area 11 of the fuel injection system 1 ,

The design of the high pressure fuel pump 2 as a plug-in pump 3 provides the advantage, among other things, that the high-pressure fuel pump, also known as a diesel pump 2 can be integrated into an engine block of the internal combustion engine, which is also referred to as an engine.

The plug-in pump 3 can be operated with both a fuel metering unit and an electric suction valve with regard to fuel quantity control. Thanks to the discontinuous delivery principle of the high-pressure fuel pump 2 can operate the fuel injection system 1 Pressure pulsations occur which are undesirable per se. The pressure pulsations can be in the low pressure range 12 reproduce where their occurrence is also undesirable.

To reduce pulsation pressure peaks in the low pressure range 12 is an external damper module 14 between the low pressure area 12 and the pump inlet 10 the high pressure fuel pump 2 arranged. The external damper module 14 includes a housing 15 with an additional volume 16 , through which the unwanted pulsation pressure peaks in the low pressure range 12 can be effectively reduced.

The damper module 14 is also with a hydraulic resistance 19 fitted. The hydraulic resistance 19 is designed as a throttle in the damper module 14 is integrated. The hydraulic resistance 19 can also be designed as a panel. The hydraulic resistance 19 is a return and / or vent connection 18 assigned, which is also in the damper module 14 is integrated. The hydraulic resistance designed as a throttle or orifice 19 provides advantageous ventilation of the low pressure area 12 as well as for a constant return flow in the operation of the fuel injection system 1 ,

In the 2 to 4 is an embodiment of the damper module 14 out 1 shown in different views. The damper module 14 includes a housing 20 with a basic body 21 , The main body of the housing 21 has essentially the shape of a straight circular cylinder jacket in the housing 20 an additional volume 36 limited. The main body of the housing 21 is in the 2 to 4 through an outer shell at the top 22 and in the 2 to 4 below through an outer shell 23 completed.

The main body of the housing 21 includes how to get in 3 sees three through holes 31 . 32 . 33 , The through holes 31 to 33 are each bordered by an outwardly bent peripheral edge. The through holes 31 to 33 are used to hold and fasten a low pressure connection piece 24 , a connection connector 25 and a return and / or vent connection 26 , The spatial arrangement of the nozzle 24 to 26 on the housing base 21 may vary.

The main body of the housing 21 and the two outer shells 22 . 23 are as formed sheet metal parts 41 . 42 . 43 executed. The three socks 24 to 26 are as turned parts 44 . 45 . 46 executed. For the joining process of the three formed sheet metal parts 41 to 43 and the turned parts 44 to 46 a material connection method is chosen. The formed sheet metal parts are particularly advantageous 41 to 43 welded together. The turned parts 44 to 46 are also advantageous with the housing base 21 welded.

The low pressure connector 24 serves to represent a connection between the low pressure area ( 12 in 1 ) and the damper module 14 , The connection connector 25 serves to represent a connection between the damper module 14 and the pump inlet ( 10 in 1 ) the high pressure fuel pump ( 2 in 1 ). The return and / or vent connection 26 serves to display the return and / or vent connection ( 18 in 1 ) of the damper module 14 ,

The return and / or vent connection 26 simultaneously provides the output or return for the damper module 14 About the return and / or vent connection 26 fuel is returned. The return of the fuel via the damper module 14 is also called return.

A hydraulic resistance 35 that the hydraulic resistance 19 in 1 is in the return and / or vent connection 26 integrated how to 4 sees. The pillars 24 to 26 are designed to easily connect hydraulic lines to the damper module 14 enable. So the damper module 14 in a simple way external, i.e. outside the high-pressure fuel pump ( 2 in 1 ) to be ordered.

The damper module is in operation 14 completely filled with fuel, especially diesel fuel. In the event of pressure pulsations in the fuel injection system ( 1 in 1 ), which is in the damper module 14 continue, the two outer shells primarily expand 22 . 23 , The outer shells deform 22 . 23 advantageously elastic. A further increase in pressure is prevented by the additional volume released.

So with the damper module 114 Pulsation fluctuations at one in 1 with 13 designated input of the damper module 14 can be effectively reduced, for example to plus / minus one bar. The return flow is advantageous behind the hydraulic resistance 18 respectively 35 arranged and thus particularly good against the high-pressure fuel pump ( 2 in 1 ) generated pulsations protected.

In 5 is the low pressure connector 24 or the same connection connection piece 25 shown in longitudinal section. The connection piece designed as a turned part comprises a socket body 50 , on the radially outside three ring beads 51 . 52 . 53 are arranged. The ring beads 51 to 53 are evenly spaced from each other in the axial direction.

This in 5 left end of the connector 24 represents a fastening end 54 with which the connecting piece 24 on the housing base ( 21 in the 2 to 4 ) is attached. This in 5 right end of the connector 24 represents the neckline 55 that Stutz end 55 serves together with the ring beads 51 to 53 for this purpose, a (not shown) hydraulic line end or fuel line end stably on the connecting piece 24 to fix.

In 6 is the return and / or vent connection 26 , which is also used as a return connection or return connection connection 26 can be referred to, shown alone in longitudinal section. The return and / or vent connection or return connection connection 26 includes, as well as the connection piece 24 in 5 , a nozzle body 60 , which essentially has the shape of a straight circular cylinder jacket. Radially outside are on the nozzle body 60 three ring beads 61 to 63 educated.

An in 6 right end of the nozzle 65 is carried out exactly like the nozzle end 55 in 5 , In contrast to 5 is an in 6 arranged fastening end 64 the return and / or vent connection 26 with a hydraulic resistor 68 fitted. The hydraulic resistance 68 is from a central through hole 69 into a final body 70 the return and / or vent connection 26 shown.

The final body 70 closes the fastening end 64 to the extent that a passage of hydraulic medium only through the hydraulic resistance 68 performing through hole 69 is possible. Inside the end body points 70 a funnel-like depression 71 at the center of which is the through hole 69 is arranged. Through the in the return and / or vent pipe 26 integrated throttle 68 the pulsations can advantageously be reduced to significantly less than 0.5 bar in the return.

Because the stretch of the case 20 of the damper module 14 is limited, especially with regard to the yield strength of the sheet metal material and its service life under changing loads, must be in operation in the damper module 14 occurring pressure can be limited. This can be achieved, for example, with a pressure-controlled electric fuel pump. With the pressure-controlled electric fuel pump, a pressure sensor detects the pressure in the low pressure range ( 12 in 1 ). If the pressure rises above a predetermined threshold, the electric fuel pump regulates down.

Alternatively, the pressure in the damper module 14 through an overflow valve in the low pressure range ( 12 in 1 ) can be limited. The overflow valve can be located at various points in the low pressure area or low pressure circuit ( 12 in 1 ) can be integrated, for example in a tank module, in particular in front of a fuel filter, or also in the damper module 14 itself. With an arrangement of the overflow valve in the damper module 14 a valve in connection with a throttle would be advantageous, for example in the return and / or vent connection 26 can be integrated.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102015202992 A1 [0002]
• DE 102016219247 A1 [0002]

Claims (10)

Damper module (14) with a high-pressure fuel pump (2) in a fuel injection system (1), the damper module (114) for damping pressure pulsations comprising a housing (15; 20) with an additional volume (16; 36), characterized in that the housing (15; 20) of the damper module (14) from formed sheet metal parts (41-43) is formed. Damper module after Claim 1 , characterized in that a low-pressure connection piece (24) and a connection connection piece (23) for connection to the high-pressure fuel pump (2) are attached to the housing (15; 20) of the damper module (14). Damper module after Claim 2 , characterized in that the low-pressure connection piece (24) and the connection connection piece (23) are designed as identical parts. Damper module according to one of the preceding claims, characterized in that the damper module (14) has a return and / or ventilation connection (18) with a hydraulic resistor (19). Damper module after Claim 4 , characterized in that the hydraulic resistance (19; 35) is integrated in a return and / or vent connection (26). Damper module according to one of the preceding claims, characterized in that the housing (15; 20) of the damper module (14) comprises a housing base body (21) which has the shape of a straight circular cylinder jacket. Damper module after Claim 6 , characterized in that the housing base body (21) has through holes (31-33) for fastening one or the low-pressure connection piece (24), one or the return and / or venting piece (26) and one or the connection piece (23). Damper module after Claim 7 or 8th , characterized in that the basic housing body (21) is closed by two outer shells (22, 23). Damper module after Claim 8 , characterized in that the outer shells (22, 23) are designed as identical parts. Housing (15; 20), in particular housing base body (21), outer shell (22, 23), low-pressure connection piece (24), connection connection piece (23) and / or ventilation piece (26) for a damper module (14) according to one of the preceding claims.

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