DE1096113B - Fuel system for a drive unit for vehicles, in particular land vehicles - Google Patents

Description

GERMAN

The invention relates to a fuel system for supplying one from a main internal combustion engine and an auxiliary internal combustion engine, both preferably working with fuel injection, existing drive unit for vehicles, in particular land vehicles.

Drive units of the type described above and their use are known. The Main internal combustion engine with its large power as the actual drive source, while the auxiliary internal combustion engine preferably drives a generator set.

The invention has the task of providing a fuel supply system with the simplest structure to create that with the least amount of effort in terms of line length, connecting lines, valves, etc. Organs and related elements a satisfactory Supply of both internal combustion engines with fuel under extreme operating conditions and also during start-up. To this end, the invention is based on a fuel system of the introductory part mentioned type, which has facilities that on the one hand supply both internal combustion engines at the same time and on the other hand each internal combustion engine for itself from one and the same Allow fuel storage system.

It should be noted in advance that the invention must not be confused with such known land vehicles, in which two separate internal combustion engines either for common drive or to drive the vehicle with one engine (with the other machine shut down).

In vehicles of this type, it is already known to supply both internal combustion engines with fuel at the same time or each machine individually from one and the same fuel tank ; however, the invention has no relation to vehicles of this type.

Rather, it is within the scope of the object of the invention that the second machine represents a real auxiliary unit, not one that may also drive the vehicle, but an auxiliary machine, which is used to supply the internal equipment of the vehicle is used, for example, to generate the required electrical power, which in turn for starting the main internal combustion engine is used.

In systems with main and auxiliary internal combustion engine understood in this sense, according to A first feature of the invention proposed, on the one hand, the supply of both internal combustion engines at the same time and on the other hand each machine for itself from one and the same fuel supply system Fuel system for a drive unit

for vehicles, in particular

Land vehicles

Applicant:

Daimler-Benz Aktiengesellschaft,
Stuttgart-Untertürkheim, Mercedesstr. 136

Dipl. ^ Ing. Ulrich Anders, Stuttgart-Untertürkheim,
has been named as the inventor

to undertake. The auxiliary machine is therefore not assigned its own fuel tank, as is known and customary, which results in a simplification of the system.

In systems according to this first feature of the invention, one could think of the relatively to cover lower fuel requirements of the auxiliary machine that on the main internal combustion engine Branch connections are provided for the fuel supply and drainage to and from the auxiliary machine will. However, it has been shown that such a solution is unsatisfactory, as it is with such Systems depend on being able to install, expand and replace each of the machines as quickly as possible, without having to consider the other machine.

For this reason and in order to get by with a minimum of connecting pieces, the invention proposes according to a second feature that both the main internal combustion engine as well the auxiliary internal combustion engine only with two connections, one inlet connection and each a drain connection directly connected to the rest of the line system assigned to the vehicle are. The invention therefore does not consist in the first-mentioned or second feature as such but in the combination of these features in a fuel system of the type mentioned in the introduction. You Also does not apply to those internal combustion engines that work without a fuel return (drain connection).

The drawing, which represents an embodiment of the invention, illustrates the fuel supply system of the drive unit in the scheme.

009 680/147

The fuel supply system consists on the one hand of a main circuit H including the main internal combustion engine 11 with a feed pump 13 driven by an electric motor 12, which sucks fuel from a withdrawal container 14 and presses it to the main internal combustion engine 11 and the auxiliary internal combustion engine 15. Parallel to the main circuit H , a secondary circuit N including the auxiliary internal combustion engine 15 is connected, which, viewed in the flow direction, branches off from the main circuit H after the feed pump 13 and flows into the main internal combustion engine 11 again.

A bypass line U , which bypasses the feed pump 13, is assigned to the secondary circuit N. A blocking element 16 (check valve) is installed in it, which allows fuel to flow from the withdrawal container 14 to the secondary circuit N , but blocks the same in the opposite direction.

Furthermore, the fuel supply system consists of a tank circuit B, which is parallel to the main circuit // and connects the withdrawal tank 14 with two storage tanks 17 and 18, which are connected side by side and whose inflow lines 17 'and 18' and outflow lines 17 "and 18" each a multiway valve 19 or 20 alternately included in the container circuit B so that a feed pump 21 sucks fuel either from the reservoir 17 or from the reservoir 18 and presses it into the removal container 14 so that it is always filled.

The main internal combustion engine 11 has only two connection points opposite that of the vehicle (not the internal combustion engine) assigned line system, an inlet connection 22 and a Return port 23. The same applies to the auxiliary internal combustion engine 15, which also has only one inlet connection 24 and a return connection 25 has.

The system works as follows: During normal operation, the feed pump 13 feeds both internal combustion engines 11 and 15 with fuel from the withdrawal container 14. Too much fuel flows back into the withdrawal container 14, which is continuously fed by the pump 21 via the container circuit B from one of the two storage containers 17 or 18 is filled. The multi-way taps 19 and 20 are switched so that only one of the two storage containers 17 or 18 is always conveyed.

The proposed fuel supply system is particularly suitable for drive units of motor vehicles, which also operate under extreme operating conditions should remain operational at all times, such as B. Vehicles operating in arctic zones should. Under such circumstances, the electrical power will normally drop due to the low temperatures Starter drive off because the battery then fails. On the other hand, however, are electrical Driven fuel pumps in fuel injection engines to ensure that they work of the injection system, as there are vapor bubbles in the line system rinse away immediately and therefore from the start of the internal combustion engine to a continuous, Guarantee bubble-free fuel flow.

To start the main internal combustion engine 11, the auxiliary internal combustion engine 15 z. B. started by compressed air. An auxiliary pump 26 mechanically driven directly by it sucks in fuel from the withdrawal container 14 via the bypass line U and the secondary line N. The auxiliary internal combustion engine 15 generates electrical current by which the motor 12 is set in motion, which drives both feed pumps 13 and 21, so that then finally the main internal combustion engine 11 can be started in a manner known per se, for. B. by means of a Leonard rate, for which the auxiliary internal combustion engine generates 15 electricity. The auxiliary pump 26 can also run during normal operation.

ίο Since the design of the fuel system according to the invention also allows the auxiliary internal combustion engine 15 to run independently of the main internal combustion engine 11 due to the bypass line U and with the help of the feed pump 26 mechanically driven by the auxiliary internal combustion engine 15, the latter can also advantageously be used to keep the cooling water warm for the entire drive unit can be used for the purpose of an immediate operational readiness of the vehicle, and it can also serve to generate electrical current in order to keep all electrical devices of the vehicle in working order.

To the following claims it is noted that for the subjects of the subclaims a protection detached from the main idea of the invention (claim 1) is not desired.

Claims (7)

Patent claims: 1. Fuel system for supplying a main internal combustion engine and an auxiliary internal combustion engine, both preferably working with fuel injection, existing drive units for vehicles, especially land vehicles witnesses, characterized by devices which, on the one hand, supply both internal combustion engines (11 and 15) simultaneously and on the other hand each internal combustion engine for itself allow one and the same fuel supply system, and further characterized in that both the main internal combustion engine (11) and the auxiliary internal combustion engine (15) each only with two connections, one inlet connection (22 or 24) and one outlet connection each (23 or 25) is connected to the rest of the line system assigned to the vehicle. 2. System according to claim 1, characterized by a main circuit (H ) including the main internal combustion engine (11) with an electrically driven fuel feed pump (13) which sucks fuel from a common extraction container (14) and feeds it to both internal combustion engines (11 and 15) by a secondary circuit (N) which includes the auxiliary internal combustion engine (15) and, viewed in the direction of flow, branches off from the main circuit (H) after the feed pump (13) and flows into the main internal combustion engine (11) again, the secondary circuit (N), is assigned which has an auxiliary pump (26) itself, a feed pump (13) of the main circuit (H) prompt line (bypass line U), which is locked to the main circuit (H) towards, further characterized by a fuel tank circuit (B) with a fuel pump (21), which sucks fuel from one or more storage containers (17 or 18) and fills the withdrawal container (14). 3. Plant according to claim 1 and 2, characterized in that two in the container circuit (B) juxtaposed fuel storage tanks (17 or 18) are provided, each of which is provided with an inlet line (17 'or 18') and an outlet line (17 "or 18") via a reversing device, e.g. multi-way cocks (19 or 20), are included in the tank circuit (B) and can be switched alternately. 4. System according to claim 1 and 2, characterized in that the electrically operated feed pump (13 ) located in the main circuit (H) and the filling pump (21) located in the container circuit (B) sit on a common shaft which is driven by an electric motor (12 ) is driven. 5. Plant according to claim 1 and 2, characterized in that the auxiliary pump (26) of the secondary circuit (N ) is mechanically driven by the auxiliary internal combustion engine (15). 6. Installation according to one or more of the preceding claims, characterized in that the auxiliary internal combustion engine (15) is started in a manner known per se by compressed air and then generated electricity to drive the electric motor (12). 7. Plant according to one or more of the preceding claims, characterized in that that the current generated by the auxiliary internal combustion engine (15) to drive an electrically operating Drive unit, z. B. a Leonard sentence, which is the main internal combustion engine (11) starts. Considered publications:
German Patent Nos. 831 807, 955 732;
U.S. Patent No. 2,267,066. 1 sheet of drawings