Damper element

A damper element is proposed which serves to damp a pulsating fluid flow, and in particular to smooth out and reduce pressure fluctuations arising in fuel supply systems for internal combustion engines in motor vehicles. The damper element includes at least one damper diaphragm which is fastened in a damper housing and defines a fluid chamber on one side. A connection fitting is disposed on the damper housing and is inserted into a plug connection of a fluid flow cross section. A flow opening is embodied in the fluid flow cross section, being open toward the fluid chamber and toward the fluid flow cross section. The flow opening and the fluid flow cross section are penetrated by a flow tube arranged to protrude therethrough, and into which a first fluid line, which discharges into the fluid chamber, is embodied. Between the flow tube and the wall of the flow opening, an annular, second fluid line is embodied.

BACKGROUND OF THE INVENTION 
The invention is based on a damper element as generally defined 
hereinafter. 
A damper element is already known in which the connection to the flowing 
fluid is effected via two separate connection fittings, so that when the 
element is installed a separate flow connection must be established for 
each of them. This produces problems in terms of sealing and requires 
additional space for accommodating the element. 
OBJECT AND SUMMARY OF THE INVENTION 
The damper element according to the invention has the advantage over the 
prior art that when the damper element is installed only a plug connection 
needs to be made, and not only is less space required but only one 
connection needs to be sealed off. 
To reduce the required space still further, it is advantageous to make the 
plug connection protrude into the fluid flow cross section. It is 
particularly advantageous to use the damper element according to the 
invention in connection with a fuel supply system of an internal 
combustion engine, and to dispose it between the fuel distributor tube and 
the fuel feed pump. 
The invention will be better understood and further objects and advantages 
thereof will become more apparent from the ensuing detailed description of 
a preferred embodiment taken in conjunction with the drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The damper element 1 shown in the drawing by way of example has a damper 
housing comprising a bottom part 2 and a cap 3. Between the bottom part 2 
and the cap 3, a damper diaphragm 4 is fastened in a sealing manner at its 
circumference by means of crimping as at 5 and thus divides a damper 
chamber 6 in the cap 3 from a fluid chamber 7 in the bottom part 2. A 
fastening flange 9 and a connection fitting 10 are secured in a sealed 
manner on the bottom part 2 remote from the damper diaphragm 4. The 
connection fitting 10 is inserted into a plug connection 11, which is 
sealingly connected with the wall 12 of a fluid flow connection 13. The 
plug connection 11 advantageously protrudes into the fluid flow cross 
section. Sealing between the plug connection 11 and the connection fitting 
10 can be effected by means of a sealing ring 14. A flow opening 16 is 
formed in the connection fitting 10, being open toward the fluid chamber 7 
and the fluid flow cross section 13. 
Protruding through the flow opening 16 is a flow tube 17, which likewise 
passes through the fluid flow cross section 13 and is secured in a sealing 
manner on the wall 12 of the fluid flow cross section 13. A first fluid 
line 18 is embodied in the flow tube 17; this first fluid line 18 is open 
toward the fluid chamber 7 and fluid, by way of example, can flow by way 
of it in the direction toward the fluid chamber 7. Between the flow tube 
17 and the wall 16 of a flow opening in the connection fitting 10, an 
annular, second fluid flow line 19 is formed, which keeps open the 
connection between the fluid chamber 7 and the fluid flow cross section 
13. The damper element 1 is secured via the fastening flange 9 and a 
further fastening flange 20, disposed on the wall 12 of the fluid flow 
cross section 13, by means of screws 21. Thus when the damper element 1 is 
installed, all that needs to be done is to insert the connection fitting 
10 of the damper element 1 into the plug connection 11 and to perform the 
positional fixation via the screws 21. 
In an advantageous application of the invention, the damper element 1 is 
integrated by way of example into a fuel injection system, by connecting 
the flow tube 17 with the pressure side of a fuel feed pump, not shown, 
which effects a pulsed fuel feed. The flow tube 17 in this application is 
disposed on the fuel distributor tube, acting as the fluid flow cross 
section 12, 13, through which the individual injection valves are supplied 
with fuel. In this case not only are fuel pulsations of the fuel which are 
caused by the fuel feed pump damped in the fluid chamber 7, but also 
pulsations arising from the opening and closing of the fuel injection 
valves and which reach the fluid chamber 7 through the fuel distributor 
tube 12, 13 and the second fluid line 19. 
The foregoing relates to a preferred exemplary embodiment of the invention, 
it being understood that other variants and embodiments thereof are 
possible.