EP2017462A1 - Method and apparatus for cleaning a fluid line - Google Patents

Abstract

The method involves guiding the fuel through a section (11) of a medium line (2). A filter element (6) which is provided to filter the fuel is arranged in a bypass (4). The bypass is locked by a fastening element (3), which is implemented as a thermal valve. The filtration is deactivated after specific operating condition, when operating temperature of the fastening element is achieved. An independent claim is also included for a device for cleaning a section of medium line of combustion engine.

Description

The invention relates to a method for cleaning at least a portion of a medium line of an internal combustion engine. The invention also relates to a device for carrying out the method.

Medium lines such as or fuel lines of an internal combustion engine are production-related often manufacturing residues, such as chips or the like. In order to ensure the service life of, for example, high-pressure fuel pumps of common-rail engines, the medium lines or the low-pressure side of the high-pressure pump fuel lines are flushed before their installation on the internal combustion engine by means of a cleaning liquid and cleaned. Isopropanol is currently used as cleaning fluid. This purging is required for all the vacuum side fuel lines which are arranged between the main filter and the high pressure pump. The known cleaning method, depending on the number and length of the fuel line, very expensive and must be performed to avoid additional contamination in a special clean room. The transport of the medium lines or fuel lines to and from the clean room increases the cost in addition.

Therefore, the invention has the object to improve a method and an apparatus of the type mentioned above so that the aforementioned disadvantages are repealed.

• Durchleiten eines Betriebsstoffes durch den zumindest einen Abschnitt einer Mediumleitung;
• Filterung des Betriebsstoffes durch ein Filterelement
• Deaktivierung der Filterung nach Vorliegen einer bestimmten Betriebsbedingung.

According to the invention, the procedural aspect of the object is achieved by carrying out the following steps:

• Passing a fuel through the at least one portion of a medium line;
• Filtering of the fuel through a filter element
• Deactivation of the filtering after the existence of a specific operating condition.

In this case, the invention is based on the idea that when starting an internal combustion engine, the passage of a fuel through a medium line any impurities and / or contaminants removed from this medium line. Subsequent filtering prevents impurities / contaminants from being carried on with the fuel. The medium line is cleaned in this way. After some time / duration of operation, the filtering can be deactivated, since then usually all impurities / contaminants are washed out of the medium line.

By means of the bypass according to the invention, the fuel, such as fuel such. B. diesel, which entrains the impurities in the at least one portion of the medium line and transported through the bypass to the filter element, filtered so that z. B. manufacturing residues z. B. can not get into a high-pressure pump, but are collected by the filter element. Thus, the at least one section of the medium line, preferably the fuel or diesel line from the fuel tank to the high pressure pump can be sufficiently cleaned of the manufacturing residues, without the costly cleaning measures must be performed in clean rooms. At the same time it is ensured that due to the filtering out of harmful manufacturing residues, the life of the high-pressure pump according to the known cleaning with cleaning media such. B. Isopropanol is secured.

The cleaning process is preferably carried out by the manufacturer. Usually, for example, fuel z. B. diesel from a central tank filled in the fuel tank of the motor vehicle. The fuel or diesel has a relatively low temperature of about 20 ° C. After the engine is first started by the manufacturer, the fuel heats up to a higher temperature, for example 80 ° C., due to friction and the compression of the fuel in a fuel pump. This effect is advantageously exploited by using a thermovalve responsive to the temperature change as the closure element. At the said "cold" fuel temperatures, the closure member or thermal valve remains in a bypass opening position (use position).

In the use position of the closure element, the bypass is opened after the first start of the internal combustion engine, and shut off the vacuum-side input to the high-pressure pump. The fuel is forced to flow through the bypass and transport the entrained production residues to the filter element, in which they are collected. Favorably, the fuel is subject to a suction pressure generated by the internal combustion engine and flows at a flow rate of, for example, 120 l / h. If the fuel or diesel reaches the operating temperature of the closure element or of the thermal valve after a sufficient time, the bypass is closed and the vacuum-side inlet to the high-pressure pump is opened. The time until the fuel has reached the actuation temperature is sufficient to remove the production residues and to clean the at least one section of the medium line or the low-pressure medium line relative to the high-pressure pump. In the further operation of the internal combustion engine, the bypass remains permanently closed, so that the fuel can flow through the bypass or through the filter element into the high-pressure pump. In this respect, there is thus a temporary filter element, the only function of which is to collect production residues from the exemplary (vacuum-side) fuel line. Once the exemplary fuel line or all fuel lines are cleaned by the fuel and the manufacturing residues are collected by the filter element, the filter element is permanently bypassed by the bypass is permanently closed. The closure element or the thermal valve is designed such that it keeps the bypass closed even at a temperature below its operating temperature, so no longer opens after the one-time closing.

Advantageously, the exemplary (vacuum side) fuel line can be installed or mounted on the internal combustion engine, and be cleaned with the inventive method in the installed on the engine position of the manufacturing residues, without cleaning before installation is necessary.

The object is also achieved by a device for cleaning at least a portion of a medium line of an internal combustion engine with the features of claim 5.

Conveniently, the medium line or fuel line is a closable by means of a closure element bypass, in which a filter element is arranged, assigned such that fuel from the at least a portion of the medium line after a first start of the engine flows through the bypass, the bypass permanently closed is when the at least a portion of the medium line is cleaned.

The closure element is expediently designed as a thermal valve, wherein the bypass in the flow direction of the fuel or fuel z. B. Diesel, for example, between the actual fuel filter and the internal combustion engine, preferably a high-pressure pump is arranged immediately. The high pressure pump has a negative pressure side and a positive pressure side. Overpressure-side fuel lines or the high-pressure pump itself are cleaned of manufacturing residues prior to installation on the internal combustion engine. On the other hand, vacuum-side fuel lines can be cleaned with the proposed device and the method according to the invention. Advantageously, the bypass is therefore arranged with its input side on the negative pressure side and with its output branch on the overpressure side, so that the high-pressure pump is bypassed.

In a preferred embodiment, the closure element is arranged on the input side of the bypass. It is also possible that the closure element is arranged in a flow channel between the input side and the corresponding output port in the medium line. The filter element is expediently arranged between the closure element and the outlet port in the bypass, that is, as seen in the flow direction of the fuel or fuel expedient behind the closure element. It is also possible to provide a flap element in front of the exit orifice, preferably a non-return flap, in order to avoid that the bypass is opened in the event of an unexpected failure of the closure element.

The filter element is designed in a preferred embodiment as a so-called disk filter, which holds the manufacturing residues in the flow direction. However, the filter element is not limited to this embodiment, but can be selected in any suitable embodiment, provided that the manufacturing residues can be sufficiently collected and recorded.

Of course, the filter element should not replace the actual fuel filter, which is to filter impurities of the fuel or diesel; Because the bypass is open only temporarily after a first start of the engine until the fuel has reached the operating temperature of the closure element and then permanently closed. This can, however, be carried out a cleaning, for example, based on the high pressure pump vacuum side fuel line after installation on the engine.

Fig. 1

in prinzipieller Darstellung einen Verbrennungsmotor mit zugeordneter Kraftstoffleitung die einen Bypaß aufweist,

Fig. 2

den Bypaß aus Figur 1 in geschlossenem Zustand, und

Fig. 3

eine mögliche Anordnung eines Verschlußelementes.

Further advantageous embodiments of the invention are disclosed in the subclaims and the following description of the figures. Show it:

Fig. 1

in a schematic representation of an internal combustion engine with associated fuel line having a bypass,

Fig. 2

the bypass FIG. 1 in closed condition, and

Fig. 3

a possible arrangement of a closure element.

In the different figures, the same parts are always provided with the same reference numerals, which is why these are usually described only once.

FIG. 1 shows in principle an internal combustion engine 1 with a medium line 2. The medium line 2 is designed as a fuel line, and is hereinafter referred to as such.

The fuel line 2 has a closable by means of a closure element 3 by-pass 4. In the bypass 4, a filter element 6 is arranged. After a first start of the internal combustion engine 1, fuel such. As fuel, such as diesel, through the fuel line 2, takes on manufacturing residues (chips or the like) and transports them through the bypass 4 to the filter element 6. In the filter element 6, the manufacturing residues are collected and permanently detained.

The bypass 4 is executed in the illustrated embodiment in longitudinal section seen U-shaped. The bypass 4 has an input side 7 and a corresponding output port 8 connected to the fuel line 2. In the illustrated embodiment, the bypass 4 runs on the input side with its input branch 9 initially oriented perpendicularly away from the fuel line 2, and merges into a parallel to the fuel line 2 flow section 11. The flow section 11 merges into an outlet branch 12, which is oriented in the direction of the fuel line 2 and opens with its outlet opening 8 in this. Of course, the bypass 4 may be implemented in any other suitable embodiment. For example, the bypass 4 could be seen in longitudinal section cut horseshoe-shaped with a curved flow section.

The closure element 3 is arranged on the input side. In the in FIG. 1 shown position, the closure element 3 is in a bypass 4 opening position (use position), so that fuel, for example diesel flows through the bypass 4 and the filter element 6 in the direction of the outlet port 8. The flow direction is shown by the arrows 13.

The filter element 6 is arranged in the flow direction of the fuel (arrow 13) behind the closure element 3.

In FIG. 1 is exemplified a common rail line of a diesel engine with a high-pressure pump, not shown. The high pressure pump, not shown, has a negative pressure side and a positive pressure side. The bypass 4 is arranged so that the input side 7 on the vacuum side and the output port. 8 is arranged on the pressure side. Thus, the bypass 4 bypasses the high-pressure pump. This is favorable for the purposes of the invention, since the overpressure-side fuel line (as seen from the high pressure pump) and the high-pressure pump itself are already cleaned of manufacturing residues. By means of the filter element 6 so the production residues of at least a portion of the fuel line, preferably the vacuum-side fuel line are collected, without that they can get into the high-pressure pump.

The fuel, for example diesel is filled from a central tank in the fuel tank of the motor vehicle and has a relatively low temperature of about 20 ° C. After a first start at the manufacturer of the internal combustion engine, the fuel flows due to suction force through the vacuum side fuel line and the opened bypass 4 and thereby transported production residues of the vacuum side fuel line to the filter element 6. The filter element 6 catches the manufacturing residues, so that the vacuum side fuel line is cleaned of them , During operation (after the first start) the fuel heats up. If the fuel reaches an operating temperature of the closure element 3, this closes the bypass 4. The closure element 3 is therefore advantageously designed as a thermal valve, which permanently closes the bypass 4, for example, at 70 ° C fuel temperature. The fuel, z. B. diesel then flows in the further operation of the internal combustion engine 1 by the high-pressure pump. The bypass 4 remains permanently closed. This condition is in FIG. 2 shown. The closure element 3 in the preferred embodiment as a thermal valve is designed such that it no longer opens after closing the bypass 4, or keeps the bypass 4 permanently closed. In this respect, it is also possible to speak of a temporary bypass 4 or filter element 6, the only function of which is to be seen in the cleaning of the vacuum-side fuel line; because after the fuel line is cleaned of the manufacturing residues, the bypass 4 remains permanently closed. The closure element 3 has a sealing device 14 on the foot side, which bears sealingly against the upper inner wall 16 of the fuel line 2 in the plane of the drawing ( FIG. 2 ).

The FIG. 2 It can also be seen that in the output branch 12, a flap element 17, for example, a non-return valve is arranged. The flap element 17 is arranged in a position permanently closing the output branch 12 when the bypass 4 is permanently closed by means of the closure element 3 or the thermo-valve. The flap member 17 prevents inflow into the bypass 4, in the event that the closure element 3, the bypass 4 should open unexpectedly. The flap element 17 serves as a kind of second closure element or as a securing element. Conveniently, the flap member 17 is permanently fixed in the output branch 12 closing position, for example, locked.

In FIG. 3 the closure element 3 is arranged in the flow channel 11, wherein the filter element 6 is arranged in the output branch 12. The closure element 3 closes the bypass 4 and simultaneously opens the entrance to the high-pressure pump. The flap member 17 can of course also in the embodiment according to FIG. 3 be provided.

The respective closure element 3 in the FIGS. 1 to 3 should be shown only by way of example, this should be carried out in each case so that on the one hand, a closing of the input side of the high-pressure pump and on the other a permanent closing of the bypass 4 is possible.

Claims (11)

Method for cleaning at least one section of a medium line (2) of an internal combustion engine (1), comprising the following steps: - Passing a fuel through the at least a portion of the medium line (2); - Filtering of the fuel through a filter element (6) - Deactivation of the filtering after the existence of a specific operating condition. Method according to claim 1,
characterized in that
the filter element (6) is arranged in a bypass (4). Method according to claim 2,
characterized in that
the deactivation of the filtering is achieved by closing the bypass (4). Method according to claim 3,
characterized in that
the operating condition for closing the bypass (4) is the presence of a specific medium temperature. Method according to claims 2 to 4,
characterized in that
the fuel is subjected to a suction pressure generated by the internal combustion engine (1) and flows through the filter element (6) arranged in the bypass (4) when the bypass (4) is opened. Device for cleaning at least a section of a medium line (2) of an internal combustion engine (1), in particular with a method according to one of the preceding claims,
characterized in that
the medium line (2) with a closure element (3) closable by-pass (4), in which a filter element (6) is arranged, is assigned such that fuel from the at least a portion of the medium line (2) through the bypass (4) flows, and the bypass (4) by means of the closure element (3) is permanently closed. Device according to claim 6,
characterized in that
the closure element (3) is designed as a thermo valve. Apparatus according to claim 6 or 7,
characterized in that
the at least one section of the medium line (2) is arranged on the negative pressure side in relation to a high-pressure pump. Device according to one of claims 6 to 8,
characterized in that
the bypass (4) with its input side (7) relative to a high pressure pump on the negative pressure side and with its output side relative to the high pressure pump is arranged on the pressure side, so that the bypass (4) bypasses the high pressure pump. Device according to one of claims 6 to 9,
characterized in that
the closure element (3) is assigned to the input side of the bypass (4). Device according to one of claims 6 to 10,
characterized in that
the filter element (6) as seen in the flow direction of the fuel behind the closure element (3) is arranged.

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