DE102007055262A1 - High pressure fuel pump with flange - Google Patents

Abstract

The invention relates to a high-pressure fuel pump for the operation of an internal combustion engine, comprising a pump housing (1) and at least one pump cylinder head (2) connected to a low-pressure inlet (4) and a high-pressure port (3), wherein in the at least one pump cylinder head (2) a pump piston (5) is arranged, which compresses by the in the pump housing (1) mounted pump camshaft movement fuel from the low pressure inlet (4) to high pressure and the high pressure port (3), wherein further on the outside of the at least one pump cylinder head (2 ) and the pump housing (1), a flange (6) is arranged, in which lines of the high pressure port (3) are arranged.

Description

The The present invention relates to a high pressure fuel pump for the operation of an internal combustion engine, consisting of a pump housing and at least one with a low pressure inlet and a high pressure connection connected pump cylinder head, wherein in the at least one pump cylinder head a pump piston is arranged, which by the by a in the pump housing mounted pump camshaft impressed Move fuel from the low pressure inlet to high pressure compressed and promotes to the high pressure port.

State of the art

From the WO 2005/052356 already a high-pressure fuel pump is known, which consists of a split pump housing, in which a pump camshaft is mounted. This pump camshaft drives an eccentric and a polygonal training arranged in the pump housing pump piston. Above this pump piston, a pressure chamber is arranged, which is connected to the one with lines of a low pressure circuit and the other with a high pressure port of a high pressure accumulator. During operation of the high pressure fuel pump generates a rotational movement of the pump camshaft with the aid of the eccentric and the polygonal training a translational movement of the pump piston, which sucked fuel in the high pressure chamber located above it, compressed and conveyed to the high pressure port. It will be clear to a person skilled in the art that a pump design is possible in which the pump piston and the pressure chamber are integrated in a pump cylinder head, which is then placed on the housing.

disadvantageous The known solution is that the pump housing must be made of a material of high strength to the high loads in the area of the high-pressure lines and the high-pressure connection withstand. This means a high production cost.

It Therefore, the object of the present invention is a high pressure fuel pump to create, in which the pump housing made of a material lower strength is made.

According to the invention this task solved that on the outside the pump cylinder head and the pump housing a flange is arranged, arranged in which lines of the high pressure port are. This flange can be made of a higher strength gray cast iron or be made of steel to withstand the stresses of high pressure withstand standing fuel. This makes it possible to manufacture the pump housing from cast iron or aluminum, because this no longer receives high pressure lines. this leads to to a reduction of the production costs or the weight the high pressure fuel pump.

In Further development of the invention are also the lines of the low pressure inlet the high-pressure fuel pump integrated into the flange. Is advantageous in this case, that additional lines for feeding the under low pressure fuel to the area of high pressure generation can be saved, which reduces the production cost.

In Another embodiment of the invention is a feed pump for generating low-pressure fuel of the low-pressure inlet integrated into the flange. This can be a very realize compact high pressure fuel pump, with very short Cable routes between low pressure and high pressure generation.

In Further development of the invention is the flange over each other spaced screws in the area of the lines of the high-pressure connection with connected to the pump cylinder head. This will ensure that flange and pump cylinder head in the area of high pressure lines lie flush and no drift apart of the two components occurs even at high fuel pressures.

In A further embodiment of the invention is in the region of the lines the high-pressure connection between flange and pump cylinder head arranged a high pressure seal. By this measure becomes a reliable seal between pump cylinder head and flange ensured.

In Development of the invention, the flange has in the near Environment of the high-pressure seal over an undercut. Thereby is achieved that the Hertzian pressure on the high pressure seal evenly distributed.

In a further embodiment of the invention are in more than one Pump cylinder head the high pressure connections of each Pump cylinder heads merged in the flange. By This measure can individual, the high-pressure accumulator leading lines can be saved, reducing the manufacturing cost reduced.

Further, The measures improving the invention will be described below together with the description of a preferred embodiment of the invention with reference to a figure shown in more detail.

embodiment

The single FIGURE shows a sectional view of the high-pressure fuel pump according to the invention perpendicular to a pump camshaft and along the pump piston. This high pressure fuel pump consists of a pump housing 1 on which a pump cylinder head 2 is attached, in which a pump piston 5 is guided. The pump piston 5 stands at its lower end with a polygon 10 , a pump camshaft, not shown, in contact, while at its upper end a pressure chamber 11 is arranged, in which the fuel during movement of the pump piston 5 is compressed to high pressure. This pressure room 11 becomes during a downward movement of the pump piston 5 through a low pressure inlet 4 supplied with low-pressure fuel and is above lines and a high-pressure valve with a high-pressure connection 3 in connection to which during the compression movement of the pump piston 5 the high-pressure fuel is conveyed. Immediately on the pump cylinder head 2 is a flange 6 arranged, which lines of the high-pressure connection 3 as well as the low pressure inlet 4 receives. This flange 6 is about the screws 7a and 7b in the immediate vicinity of the lines of the high-pressure connection 3 with the pump cylinder head 2 screwed. In the transition area of the high-pressure line of the high-pressure connection 3 is between pump cylinder head 2 and flange 6 a high pressure seal 8th arranged. Below this high pressure seal 8th is an underdog 9 provided a uniform distribution of Hertzian pressure of the high pressure seal 8th to reach.

When operating the high-pressure fuel pump, the pressure chamber 11 over the flange 6 and the low pressure inlet 4 fueled, which condenses there and over the flange 6 and the high pressure port 3 is transported to a high-pressure accumulator, not shown.

1

pump housing

2

Pump cylinder head

3

High pressure port

4

Low pressure inlet

5

pump pistons

6

flange

7a, 7b

screw

8th

High pressure seal

9

Freeway

10

polygon

11

pressure chamber

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

• WO 2005/052356 [0002]

Claims (7)

High-pressure fuel pump for the operation of an internal combustion engine, consisting of a pump housing ( 1 ) and at least one with a low pressure inlet ( 4 ) and a high-pressure connection ( 3 ) associated pump cylinder head ( 2 ), wherein in the at least one pump cylinder head ( 2 ) a pump piston ( 5 ) arranged through the one in the pump housing ( 1 ) mounted pump camshaft imprinted movement fuel from the low pressure inlet ( 4 ) to high pressure and to the high pressure port ( 3 ), characterized in that on the outside of the at least one pump cylinder head ( 2 ) and the pump housing ( 1 ) a flange ( 6 ) is arranged, in which lines of the high pressure port ( 3 ) are arranged. High-pressure fuel pump according to claim 1, characterized in that lines of the low-pressure inlet ( 4 ) in the flange ( 6 ) are integrated. High-pressure fuel pump according to claim 1 or 2, characterized in that a feed pump for generating low-pressure fuel of the low-pressure inlet ( 4 ) in the flange ( 6 ) is integrated. High-pressure fuel pump according to one of claims 1-3, characterized in that the flange ( 6 ) over spaced screws ( 7a . 7b ) in the area of the lines of the high-pressure connection ( 3 ) with the pump cylinder head ( 2 ) connected is. High-pressure fuel pump according to one of the preceding claims, characterized in that in the region of the lines of the high-pressure connection ( 3 ) between flange ( 6 ) and pump cylinder head ( 2 ) a high pressure seal ( 8th ) is arranged. High-pressure fuel pump according to claim 5, characterized in that the flange ( 6 ) in the vicinity of the high pressure seal ( 8th ) about an undercut ( 9 ). High-pressure fuel pump according to one of the preceding claims, characterized in that, in the case of more than one pump cylinder head, the high-pressure connections ( 3 ) of the individual pump cylinder heads ( 2 ) in the flange ( 6 ) are merged.