DE102006007574A1 - Injecting injector`s control valve for heavy fuel oil operation, has connection tube with specific tube length and arranged between upper control chamber and port valve, where fuel is supplied to upper and lower chamber - Google Patents

Abstract

The invention relates to a control valve of an injection injector for heavy oil operation, an upper control chamber (2) being formed above a nozzle needle and a lower control chamber below, to which the fuel can be fed under pressure and a 2/2-way valve (4 ) is arranged. According to the invention, at least one connecting channel (6) with a channel length (I) of at least 10 millimeters is arranged between the upper control chamber (2) and the 2/2-way valve (4).

Description

The The invention relates to a control valve of an injection injector for heavy oil operation, being above a nozzle needle an upper control chamber and formed below a lower control room are to which the fuel is supplied under pressure and to open / close the nozzle needle a 2/2 way valve is arranged.

Out the state of the art is in both stroke and pressure controlled Injection systems known to work without servo oil that control the valve opening or the valve closing takes place thereby, in the the nozzle needle or a 3/2 way valve via the pressure of the fuel, the on top of the nozzle needle acting piston rod or on the 3/2 way valve acts and this Control components in the closed position holds.

to Initiation of the injection, the space above the control components over 2/2 directional control valve and a so-called drain throttle relieved of pressure. Since the fuel feed over an inlet throttle, which is smaller in cross-section than the outlet throttle, is limited, the pressure in this control chamber decreases, so that the nozzle needle or the 3/2 way valve through the bottom acting fuel pressure open becomes. To end the injection, the 2/2 way valve is again closed, the pressure in the control room rises again and the nozzle needle or the 3/2 way valve is due to the pressure available area ratios the top closed to the bottom.

From the DE 100 46 416 C2 For example, a valve training for control valves is known, in which the problem with known common rail injection systems for HFO (= Heavy Fuel Oil = heavy oil), namely the separation of 2/2 way valve and solenoid via a rod (See rod 9 in the figures).

Especially in stroke-controlled leak-free common rail injectors in which If the 2/2 way valve is located directly above the nozzle needle, it must either The magnet can be installed very deep in the injector, which means heavy oil operation is unfavorable because of the temperature load. Because of the temperature load is from other manufacturers an extended version of the above-mentioned push rod realized, creating a mechanical connection between the low-lying 2/2 way valve and the magnet is reached. However, this is technical and mechanically very complex and with problems like masses (inertia), leadership and ductility of the push rod connected.

Of these, The inventor has set himself the task, a new and improved control valve of an injection injector for the heavy oil operation to disposal to deliver.

The Task is by a control valve of a Einspritzinjektors for heavy oil operation according to claim 1 solved.

Of the Inventor has realized that it is possible is the control chamber above the nozzle needle, the previous piston rod or the 3/2-way valve over one hydraulic connection channel, in the sense of a "hydraulic rod", with the 2/2 way valve too connect.

hereby becomes a spatial Separation of 3/2-way valve, piston rod or nozzle needle and 2/2 way valve allows. It is realized a leak-free stroke-controlled injector. The previously required push rod or other mechanical Connections can now omitted.

Farther can the solenoid of the 2/2-way valve with respect to the installation position and on the thermal load in a more thermally non-critical Be installed area.

Out The inventor proposes to use the knowledge gained, a control valve an injection injector for Heavy oil, being above a nozzle needle an upper control chamber and formed below a lower control room are to which the fuel is supplied under pressure and to open / close the nozzle needle a 2/2 way valve is arranged to improve to that between upper control chamber and 2/2 way valve at least one connecting channel with at least 10 millimeter channel length is arranged.

there the connecting channel can be arranged downstream of the control chamber be. It is fluidic advantageous if the connecting channel straight or almost straight is executed.

Around in the upper control room controls the pressure by opening the 2/2 way valve To reduce, it is beneficial if between 2/2 way valve and control space at least one outlet throttle is arranged. in this connection can the outlet throttle either at the connection channel beginning and / or be arranged at the connection channel end, in each case either in the direction Control room and / or 2/2 way valve.

Of the Connecting channel may have a diameter in the range of preferably 0.5 millimeters to 8 millimeters. In addition, the connection channel a length in the range of preferably 10 millimeters to 200 millimeters.

advantageously, is the length of the connection channel between 15 mm to 150 mm. The cross-sectional area the connection channel may have a size in the range of preferably 0.25 square millimeters to 30 square millimeters.

preferred Further developments of the invention will become apparent from the dependent claims and the following description. Embodiments of the invention without being limited to this to be explained in more detail with reference to the drawings. Showing:

1 FIG. 1: partial sectional view through a known control valve of an injection injector for heavy oil operation; FIG.

2 : Partial sectional view through new control valve;

3 : Partial sectional view through an embodiment of the connecting channel;

4 : Partial sectional view through a further embodiment of the connecting channel.

Hereinafter, the present invention will be described with reference to FIGS 1 to 4 described.

The 1 shows a partial sectional view through a known control valve of an injection injector for heavy oil operation. To initiate the injection, the control room becomes 2 with a 2/2 way valve by opening a so-called drain throttle 7.4 depressurized. Since the fuel supply is limited by an inlet throttle, which is smaller in cross-section than the outlet throttle, the pressure in this control chamber decreases 2 , so that the nozzle needle or the 3/2 way valve is opened by acting on the bottom fuel pressure.

The fuel inlet, the inlet throttle, the nozzle needle and the 3/2-way valve are in 1 not shown.

To open the outlet throttle 7.4 is by a magnet 3 relieves an unillustrated spring element, whereby the rod 1 by the fuel pressure in the control room 2 raises up. The length of the rod 1 is chosen constructively so that the magnet 3 is far enough away from the lower part of the injection injector to keep thermal influences as low as possible and the space for the magnet is sufficiently large.

By the invention is an alternative construction of a control valve found be, with that on this pole, the quasi as a thermal spacer acts, can be waived.

The 2 shows a partial sectional view through a new control valve of an injection injector for heavy oil operation. The initiation of the injection process is analogous to 1 by depressurizing the control room 2 performed. The fuel is supplied via a fuel supply line with inlet throttle 7.1 the control room 2 fed. To the control room 2 Relieve the (fuel) pressure, which opens the nozzle needle, with a magnet 3 a tensioned spring element 3.1 relieved. This allows the in the control room 2 located fuel pressure via an outlet throttle 7.2 at the beginning of a connection channel 6 open a 2/2 way valve and escape.

The area of the connection channel 6 with length l, the outlet throttle 7.2 and the 2/2 way valve 4 are in 2 framed dashed lines. The 2/2 way valve 4 is executed in this embodiment as a ball that opens or closes an opening.

This connection channel 6 with length l serves to the magnet 3 for switching the 2/2 way valve 4 thermally separated from the bottom of the injector, which is heated by the combustion process. Another advantage turns out to be against the pole 1 (out 1 ), that leaks on the rod outer wall are avoided. The 2/2 way valve 4 can better seal in the thermally relieved area.

The 3 shows another possible arrangement of the outlet throttle 7.3 that's here at the end of the connection channel 6 is arranged in the direction of the 2/2 way valve.

The 4 shows a partial sectional view through a further embodiment of the connecting channel 6 , In this embodiment is at the beginning as well as at the end of the connection channel 6 one outlet throttle each 7.2 and 7.3 arranged.

It It is understood that the above features and features the claims not only in the specified combinations, but also in others Combinations or alone can be used without the framework of To leave invention.

1

pole

2

control room

3

magnet

3.1

spring element

4

2.2 way valve

5

3.2 way valve

6

connecting channel

7.1

inlet throttle

7.2

outlet throttle at the beginning of the connection channel

7.3

outlet throttle (at the end of the connection channel

7.4

outlet throttle

l

Length connecting channel

Claims (10)

Control valve of an injection injector for heavy oil operation, wherein above a nozzle needle, an upper control chamber ( 2 ) and are formed below a lower control chamber to which the fuel is supplied under pressure and to open / close the nozzle needle, a 2/2 way valve ( 4 ), characterized in that between upper control room ( 2 ) and 2/2 way valve ( 4 ) at least one connection channel ( 6 ) is arranged with at least 10 millimeter channel length (l). Control valve according to claim 1, characterized in that the connecting channel ( 6 ) on the drain side to the control room ( 2 ) is arranged. Control valve according to one or both of Claims 1 and 2, characterized in that the connecting channel ( 6 ) is rectilinear or nearly rectilinear. Control valve according to one or more of claims 1 to 3, characterized in that between 2/2 way valve ( 4 ) and control room ( 2 ) at least one outlet throttle ( 7.2 - 7.4 ) is arranged. Control valve according to claim 4, characterized in that the outlet throttle ( 7.2 ) at the beginning of the connection channel in the direction of the control room ( 2 ) is arranged. Control valve according to one or both of Claims 4 and 5, characterized in that the outlet throttle ( 7.3 ) at the connection channel end in the direction 2/2 way valve ( 4 ) is arranged. Control valve according to one or more of claims 1 to 6, characterized in that the connecting channel ( 6 ) has a diameter in the range of preferably 0.5 millimeters to 8 millimeters. Control valve according to one or more of claims 1 to 7, characterized in that the connecting channel ( 6 ) has a length (l) in the range of preferably 10 millimeters to 200 millimeters. Control valve according to one or more of claims 1 to 8, characterized in that the connecting channel ( 6 ) has a length (l) in the range of preferably 15 millimeters to 150 millimeters. Control valve according to one or more of claims 1 to 9, characterized in that the connecting channel ( 6 ) has a cross-sectional area in the range of preferably 0.25 to 30 square millimeters.