JP6483372B2 - Valve assembly for a fuel supply device and fuel supply device - Google Patents

Description

  The present invention relates to a valve assembly for a fuel supply device of an internal combustion engine. The present invention further relates to a fuel supply apparatus having the valve assembly.

  The basic configuration of the common rail fuel supply apparatus is known from Patent Document 1. The common rail fuel supply apparatus includes at least one injector for each cylinder of the internal combustion engine. Through these injectors, fuel can be injected into each cylinder of the internal combustion engine. Further, the common rail fuel supply device includes at least one low pressure pump, at least one high pressure pump, and at least one high pressure storage device for transporting fuel from the low pressure region of the common rail fuel supply device to the high pressure region. In the high pressure region between the pump device and the injector, a pressure accumulating system that is permanently under high pressure is provided. This permanent high pressure storage system, also called common rail, has one or more storage units. These storage units are connected to the pump device and to each other through a high-pressure conduit that is permanently under high pressure. The pressure accumulating system, that is, the storage unit, is further connected to the injector through a high-pressure conduit that temporarily becomes high pressure according to the injection timing. A switching valve is disposed in a high-pressure conduit that connects the injector to the storage unit and temporarily becomes high pressure according to the injection timing, and the switching valve supplies fuel to the injector according to the injection timing.

  From Patent Document 1, it is known that a safety valve and a relief valve are arranged in one of the storage units of the pressure accumulating system. Together, the safety valve and the relief valve form one load reducing device. Safety valves and relief valves can also be realized with a single valve element. After stopping the prime mover through the relief valve, it is possible to remove it from the fuel supply device toward the tank. According to Patent Document 1, the operation of the relief valve is performed by the pneumatic, hydraulic or electromagnetic through the inherent control medium. Done with.

German Patent Invention No. 10157135

  Starting from here, the object of the present invention is to create a new valve assembly for a fuel supply device and a fuel supply device having the valve assembly.

  This problem is solved by a valve assembly according to claim 1. The valve assembly according to the present invention includes a pilot valve, a main valve, and a pressure regulating valve, and the main valve can be connected to a high pressure region of the fuel supply device by a pressure connecting portion. Can be connected to the low pressure region of the fuel supply device by means of a pressure connection. That is, the pilot valve, the main valve, and the pressure regulating valve can be connected so that they can be automatically actuated according to the pressure in the low pressure region and / or according to the pressure in the high pressure region.

  The valve assembly according to the present invention enables automatic load reduction in the high pressure region of the fuel supply device after stopping the internal combustion engine or after stopping the low pressure pump of the fuel supply device by a method using a machine. Thus, it does not require operation by air pressure, electromagnetic or other methods.

  Therefore, after the prime mover is stopped, the fuel supply device can be automatically depressurized without being operated by the control device. As the control medium, the pressure of the fuel existing in the fuel supply apparatus is used. The depressurization of the fuel supply device can be performed within a few seconds using the valve assembly according to the present invention. Therefore, the injector of the fuel supply device can be effectively protected from wear.

  According to a further advantageous configuration, the pressure regulating valve is operated by the pressure connection so that the pressure regulating valve is against the adjustable elasticity of the spring element when operating pressure is applied to the low pressure region of the fuel supply device and to the low pressure region. And can be connected to automatically open. The pilot valve has a low pressure region of the fuel supply device by the first pressure connection, and a high pressure region, a low pressure region and a high pressure region of the fuel supply device by at least one choke by the second pressure connection. The pilot valve may be connected to automatically close when operating pressure is applied to the valve. The main valve may be connected by a pressure connection to the high pressure region of the fuel supply device so that the main valve automatically closes before operating pressure is applied to the high pressure region. Then, when the operating pressure in the low pressure region of the fuel supply device decreases due to the stop of the low pressure pump, the pilot valve and the main valve are automatically opened, so that it can be removed from the high pressure region toward the fuel tank. The connection of the pilot valve, the main valve and the pressure regulating valve is preferable, and the external operation by the control device is not performed after the stop of the internal combustion engine or the low pressure pump of the fuel supply device at a low cost. Allows automatic depressurization of the fuel injection system.

  A fuel supply apparatus according to the present invention is defined in claim 9. Preferred further configurations of the invention are evident from the subclaims and the following description. Embodiments of the present invention will be described in detail with reference to the drawings, but are not limited to the drawings.

1 is a schematic view of a valve assembly for a fuel supply apparatus according to the present invention.

  The present invention relates to a valve assembly and a fuel supply device, in particular a common rail fuel supply device, for a fuel supply device of an internal combustion engine, preferably configured as a large diesel engine or a marine diesel engine.

  The basic configuration of a fuel supply device configured as a common rail fuel supply device for an internal combustion engine is well known to those skilled in the art, and is already known from Patent Document 1. The present invention supports the adjustment of a predetermined operating pressure at the start of the internal combustion engine and after the internal combustion engine starts to move, both in the low pressure region and the high pressure region of the fuel supply device, and after the prime mover or the low pressure pump is stopped. Relates to a valve assembly for a fuel supply device that allows automatic depressurization by the machine of the fuel supply device.

  FIG. 1 is a block diagram of a valve assembly 10 for a fuel supply device for an internal combustion engine, particularly a common rail fuel supply device, configured as a marine diesel engine according to the present invention. The valve assembly 10 includes a pilot valve 11, a main valve 12 and a pressure regulating valve 13. The valve assembly 10 of FIG. 1 can be connected to both the low pressure region 14 and the high pressure region 15 of the fuel supply system of the internal combustion engine.

  The main valve 12, which is configured as a 2/2 direction control valve in the embodiment of FIG. 1, has two pressure connections 16 and 17. Both pressure connections 16 and 17 make it possible to connect the main valve 12 to the high pressure region 15 of the fuel supply device, both pressure connections 16 and 17 being different with respect to their pressing surfaces. The first pressure connection 16 that can be connected to the high pressure region 15 of the fuel supply device via the choke 18 has a larger pressing surface than the second pressure connection 17 of the main valve 12, and the main valve 12. Can be directly connected to the high pressure region 15 of the fuel supply device through the pressure connection 17 without a choke. When the high pressure region 15 of the fuel supply device is not pressurized, the spring element 19 presses the main valve 12 to the closed position shown in FIG. The spring element 19 can be configured to have relatively little elasticity. This is because the spring element 19 is substantially used only for positioning the main valve 12 in the non-pressurized state. When the operating pressure is applied by at least one high-pressure pump in the high-pressure region 15, the main valve 12 has the same pressure surface as the first pressure connection 16 of the main valve 12 has a larger pressing surface than the pressure connection 17. 1 to the closed position shown in FIG.

  The pilot valve 11 and the pressure regulating valve 13 can be connected to the low pressure region 14 of the fuel supply apparatus by the pressure connecting portions 20 and 21. The choke 22 in the low pressure region 14 attenuates pressure vibration in the low pressure region 14. When the low pressure region 14 is not pressurized, the pilot valve 11 is pressed to the closed position shown in FIG. Similar to the spring element 19 of the main valve 12, the spring element 23 of the pilot valve 11 is configured to have less elasticity. In the case of the pilot valve 11, the positioning of the pilot valve 11 in the non-pressurized state is exclusively performed. Used to do In some cases, the spring element 23 may be omitted completely.

  In the embodiment shown in FIG. 1, the pilot valve 11 configured as a 2 / 2-directional control valve, like the main valve 12, has a pressure connection portion 21 that can connect the pilot valve 11 to the low pressure region 14 of the fuel supply device. In addition, it has a further pressure connection 24 through which the pilot valve 11 can be connected to the high pressure region 15 via at least one choke. In FIG. 1, the choke 18 and the further choke 25 already mentioned are connected between the pressure connection 24 of the pilot valve 11 and the high pressure region 15. Both pressure connecting parts 21 and 24 of the pilot valve 11 also have different pressing surfaces, and the pressing surface of the first pressure connecting part 21 is larger than the pressing surface of the second pressure connecting part 24. In the low pressure region 14 and the high pressure region 15, when the corresponding operating pressure is applied, the pilot valve 11 is pressed to the closed position shown in FIG.

  As already described, the pressure regulating valve 13 can be connected to the low pressure region 14 by the pressure connection 20, and when the low pressure region 14 is unpressurized, the spring element 26 that can be adjusted with respect to its elasticity is a pressure regulating valve. 13 is pressed to the closing position shown in FIG. Next, when an operating pressure is applied to the low pressure region 14, the operating pressure exists in the pressure connection portion 20, and the pressure adjustment valve 13 is pressed from the closed position according to the adjusted elasticity of the spring element 26. To do. That is, in the pressure connection parts 20 and 21, the pressure adjusting valve 13 and the pilot valve 11 are pressed so as to generate a constant pressure. Thus, the pressure regulating valve 13 and the adjustable spring element 26 can be used to guarantee a constant opening pressure for the main valve 12 even when the pressure fluctuates in the fuel supply system, and the pressure connection The pressure that is too high at the part 20 and the pressure connecting part 21 leads to the opening of the pressure regulating valve 13 until the pressure at the choke 27 of the pressure regulating valve 13 drops to a desired value. Here, it is pointed out that the pressure regulating valve 13 can be incorporated in the piston of the pilot valve 11.

  In a stopped internal combustion engine, that is, as a result of the low pressure pump in the low pressure region 17 and the high pressure pump in the high pressure region 15 being stopped, the fuel supply device is non-pressurized, the valves 11, 12 and 13 of the valve assembly 10 are The position shown in 1 is taken.

  When the internal combustion engine is started and when the low pressure pump in the low pressure region 14 of the fuel supply device is started, pressure is generated by the pressure regulating valve 13 and the pilot valve 11 at the pressure connecting portions 20 and 21, and the pressure is The pilot valve 11 is pressed to the closed position shown in FIG. When the internal combustion engine is started, one or each high pressure pump in the high pressure region 15 is also started. Due to the configuration of the pressure connections 16 and 17, the main valve 12 keeps the high pressure region 15 of the fuel supply device closed when there is an operating pressure in the high pressure region 15. As already explained, pressure fluctuations in the low pressure region 14 of the fuel supply device are attenuated by the choke 22 and the pressure regulating valve 13 reduces the opening pressure for the main valve 12 during pressure fluctuations in the fuel supply device. Kept constant.

  After starting the internal combustion engine and correspondingly, after the operating pressure has been generated in the low pressure zone 14 and the high pressure zone 15 by one or each high pressure pump in the low pressure zone 14 and the high pressure zone 15, the fuel supply device A corresponding injection pressure exists in an injector (not shown). Via the choke 18, the pressure connection 16 of the main valve 12 is filled and, as already mentioned, the pressure connection 16 has a larger pressing surface than the pressure connection 17, so that the main valve 12 After the internal combustion engine is started, it is kept securely closed.

  Since the pressure connection 16 of the main valve 12 is not completely sealed, a certain amount of fuel is lost toward the fuel tank or the recovery tank 28 due to the so-called gap path (Spaltfuehrung) of the main valve 12. To do. The leakage of the pressure connection 16 of the main valve 12 is shown schematically in FIG. 1 through the choke 29, but here the pressure connection of the main valve 12 is simply not a structurally completed choke. The loss of fuel in the direction of the recovery tank 28 from the second pressure connection 16 as a result of 16 leaks is of interest. However, since more fuel is replenished through the choke 18 than is discharged in the direction of the recovery tank 28 as a result of leakage of the pressure connection 16 with respect to the basic choke 29, the pressure connection 16 of the main valve 12 is refilled. The pressure is maintained and the high pressure region 15 of the fuel supply can be maintained closed.

  When the internal combustion engine is shut down and thus the low pressure pump in the low pressure zone 14 and one or each high pressure pump in the high pressure zone 15 are shut down, the pressure in the fuel supply system drops rapidly. As a result, the pressure at the pressure connection 21 of the pilot valve 11 decreases and is a relatively high pressure still present in the high pressure region 15 of the fuel supply device, which is connected via the chokes 18 and 25 to the pressure connection of the pilot valve 11. As a result of the pressure present at 24, the pilot valve 11 opens automatically. As a result, the pressure state in the fuel supply device can be used to automatically remove or ventilate from the low pressure region 14 toward the recovery tank 28 within a few seconds after the internal combustion engine is stopped.

  In this connection, the choke 25 is larger than the choke 18, so that more fuel can flow out of the pressure connection 16 via the choke 25 than is sent to the pressure connection 16 via the choke 18. It should be noted.

  As the pressure at the pressure connection 16 of the main valve 12 is reduced, the main valve 12 is also automatically opened by the pressure at the pressure connection 17, so that the high pressure region 15 of the fuel supply device is also Within a few seconds, it can be removed or vented towards the collection tank 28 mechanically and automatically.

  The choke 30 shown in FIG. 1 indicates a pressure loss to the recovery tank 28.

  The valve assembly 10 according to the present invention automatically uses the pressure conditions in the low pressure region 14 and the high pressure region 15 of the fuel supply device to automatically switch the pilot valve 11 and the main valve 12 when the internal combustion engine is started or started. The pilot valve 11 and the main valve 12 are automatically opened within a few seconds after the internal combustion engine is stopped. This ensures automatic depressurization of the fuel supply device after the internal combustion engine is stopped without the operation of a separate control device. There is no need for pneumatic or hydraulic pressure air supply or electromagnetic or other types of actuation. Since the control medium corresponds to the working medium, i.e. fuel, there is no undesired mixing of the different media, e.g. fuel and pressurized air are not mixed during operation by pneumatic pressure. After stopping the prime mover, the opening of the pilot valve 11 and the main valve 12 of the valve assembly 10 according to the present invention and the accompanying pressure reduction of the fuel supply device are performed within a few seconds. Can be reduced. The spring elements 19 and 23 of the main valve 12 and the pilot valve 11 are configured to have a small elasticity. This is because these spring elements are substantially only used for positioning the corresponding valves 11, 12 in the non-pressurized state.

DESCRIPTION OF SYMBOLS 10 Valve assembly 11 Pilot valve 12 Main valve 13 Pressure adjustment valve 14 Low pressure area 15 High pressure area 16 Pressure connection part 17 Pressure connection part 18 Choke 19 Spring element 20 Pressure connection part 21 Pressure connection part 22 Choke 23 Spring element 24 Pressure connection part 25 Choke 26 Spring element 27 Choke 28 Collection tank 29 Choke 30 Choke

Claims (6)

A fuel supply device for an internal combustion engine configured as a marine diesel engine, in particular a valve assembly (10) for a common rail fuel supply device, comprising a pilot valve (11), a main valve (12) and a pressure regulating valve (13) A valve assembly having:
Said pilot valve (11), said main valve (12) and said pressure regulating valve (13), in response to the pressure in the low pressure region (14), and / or, depending on the pressure in the high pressure area (15), automatically so as to be operated, the main valve (12) is connectable the said high pressure region of the fuel supply device (15) by a pressure connection (16, 17), said pilot valve (11 ) And the pressure regulating valve (13) can be connected to the low pressure region (14) of the fuel supply device by a pressure connection (20, 21), and the main valve (12) is connected to the high pressure region (15). ) Is connected to the high pressure region (15) of the fuel supply device by two pressure connections (16, 17) so that the main valve (12) automatically closes when operating pressure is applied to Can be relatively large The pressure connection (16) of the first main valve (12) acting in the closing direction, which has a pressing surface, is connected to the high-pressure region (of the fuel supply device) via at least one choke (18). 15), and having a relatively small pressing surface, a second, pressure connection (17) of the main valve (12) acting in the opening direction is connected to the fuel supply device. A valve assembly (10) characterized in that it can be connected directly to the high-pressure region (15 ).   When the operating pressure is applied to the low pressure region (14), the pressure adjusting valve (13) is opposed to the adjustable elasticity of the spring element (26) and the low pressure region (14) The valve assembly according to claim 1, characterized in that it can be connected to the low pressure region (14) by means of a pressure connection (20) so as to open automatically with a guarantee of a constant operating pressure in 14). (10).   The pilot valve (11) is connected to the low pressure region (14) of the fuel supply device by a first pressure connection (21) and at least one choke (18, 18) by a second pressure connection (24). 25), when the operating pressure is applied to the high pressure region (15) and the low pressure region (14) of the fuel supply device, and the operating pressure is applied to the high pressure region (15). 3. The valve assembly (10) according to claim 1 or 2, characterized in that in some cases the pilot valve (11) can be connected to automatically close. When the operating pressure in the low pressure region (14) of the fuel supply device decreases, the pilot valve (11) and the main valve (12) automatically open, so the low pressure region (14) and the high pressure region the valve assembly according to any one of claims 1 to 3, characterized in that it can be removed toward the area (2) fuel tank from (28) (10). The valve assembly (10) according to any one of claims 1 to 4 , characterized in that the pilot valve (11) and the main valve (12) are configured as 2 / 2-way control valves. The fuel supply device of internal combustion engine formed as a marine diesel engine, in particular common rail fuel supply system, a fuel supply system having a low pressure region (14) and the high-pressure region (15), one of claims 1 to 5 A fuel supply device comprising the valve assembly (10) according to claim 1.

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