TECHNICAL FIELD OF THE INVENTION

The invention pertains to a pump device for a fuel system in combustion engines according to the preamble of patent claim 1 . The invention also pertains to a combustion engine. The invention also pertains to a motor vehicle.

BACKGROUND Fuel systems in combustion engines usually have a manual hand pump for pre-f illing of fuel in order to vent conduits.

The fuel system comprises a fuel filter housing with a replaceable insert filter. The fuel filter housing is equipped with a drain opening in order to, with the help of gravity, drain fuel back to the fuel tank when the filter is replaced. One problem with such fuel systems is that old unfiltered fuel remains due to the placement of the drain opening in relation to the tank and long return pipes. When a new filter is inserted, the unfiltered fuel is deposited accordingly on the "clean side" of the filter, i.e. downstream of the filter in the fuel's normal flow direction from the fuel tank to the engine. This fuel will then not pass through the filter before it arrives in the engine. In the event of pre- filling of fuel and subsequent start-up of the engine, there is a risk that dirt from the unfiltered fuel may be led into the injection system, causing damage.

One solution to this problem is to, at a garage, connect a suction pump to compressed air and thus to empty the fuel filter housing in connection with a filter replacement. This is a relatively costly and complex solution and can only be done at a garage. OBJECTIVE OF THE INVENTION

One objective of the present invention is to facilitate replacement of fuel filters in a fuel system. In particular, the invention relates to a pump device for fuel systems which in a cost-effective manner facilitates evacuation of fuel from filter housings in connection with filter replacement in a filter configuration.

SUMMARY OF THE INVENTION These and other objectives, which are set out in the description below, are achieved with a pump device, a combustion engine, and a motor vehicle of the type specified above, and which also have the characteristics specified in the characterising portion of the enclosed independent patent claims 1 , 6 and 7. The preferred embodiments of the pump device are defined in the enclosed non-independent patent claims 2-5.

According to the invention, the objectives are achieved with a pump device for fuel systems in a combustion engine, the pump device of which is arranged for manual pumping of fuel from a fuel tank via a fuel filter configuration to the engine, so that the fuel system comprises means to evacuate remaining fuel from the fuel filter configuration. The evacuation of the fuel is intended to take place manually through the said pump device being used to suck the fuel from the fuel configuration. Thus, a cost-effective evacuation is facilitated in that the existing pump device for manual pumping is used also for the evacuation, so that no costly extra suction devices are required. Thus, consequently, the evacuation of fuel from the fuel filter configuration may, e.g. in connection with filter replacement, easily and cost- effectively be achieved manually regardless of where the vehicle is located. Consequently, unfiltered fuel does not end up on the clean side of the filter and eventually in the engine, and operational security is thus improved accordingly.

Said pump device comprises a pump cylinder with a piston configuration for the said manual pumping/evacuation and a first space via which fuel is pumped from the said fuel tank and a second space via which the said fuel filter configuration is evacuated. Thus, a construction is provided which easily and efficiently facilitates both manual pumping of fuel from the fuel tank to the engine and manual evacuation of fuel from the filter configuration, e.g. back to the fuel tank. If, for example, the vehicle is at a garage, the fuel may instead be evacuated to a separate container.

According to one embodiment, the said pump device is in a first mode arranged for manual pumping of fuel from the fuel tank to the engine and in a second mode arranged for manual evacuation of fuel from the said fuel filter configuration. The pump device is manually adjustable between the said two modes. Thus, in addition to manual pumping, simple and effective manual evacuation for evacuation of fuel with the pump device is also facilitated.

According to one embodiment of the pump device, the said cylinder comprises a rotatably arranged insert inside the cylinder around the cylinder's central shaft, which in the said first mode is arranged to facilitate fuel flow through the first space and in the second mode to facilitate fuel flow through the second space. Thus, a simple and effective manual pumping/evacuation of fuel with a piston configuration is facilitated, where both pumping and evacuation, i.e. suction, may be achieved with the same piston element in the piston configuration which facilitates a compact construction. Through this construction, in the first mode, because of the position of the insert, only pumping is permitted, i.e. flow from the fuel tank to the engine, and in the second mode, by changing the position of the insert, only evacuation (suction), i.e. flow from the filter configuration back to the fuel tank or another container, is permitted. According to one embodiment of the pump device, the said piston configuration comprises two piston elements, where a first piston element is arranged to operate in the said first space and where a second piston element is arranged to operate in the said second space, so that the said piston elements are arranged to alternately enable transmission by rotating the piston configuration around the said central shaft. According to one embodiment, the transmission is facilitated by the piston element being brought into engagement with a piston rod comprised in the piston configuration, through rotation around the said central shaft. According to one embodiment of the pump device, only the said first piston element is brought into engagement in the said first mode for fuel flow, and so that only the said second piston element is brought into engagement in the said second mode for fuel flow. Thus, a simple and efficient manual pumping/evacuation of fuel with a piston configuration is facilitated, where no extra insert is required, but instead the piston configuration, with the first and second piston elements, achieve pumping in the first mode and evacuation in the second mode. Through this construction, in the first mode, because the first piston element is brought into engagement and the second piston element is disconnected, only pumping is permitted, i.e. flow from the fuel tank to the engine, and in the second mode, because the second piston element is brought into engagement and the first piston element is disconnected, only evacuation, i.e. flow from the filter configuration back to the fuel tank or another container, is permitted. Thus, efficient pumping is facilitated in the first mode and efficient evacuation in the second mode.

DESCRIPTION OF DRAWINGS

The present invention will be understood more easily with reference to the following detailed description read in conjunction with the enclosed drawings, where the same reference numerals refer to the same parts throughout the several views, and in which: Fig. 1 schematically illustrates a motor vehicle, according to an embodiment of the present invention;

Fig. 2a-b schematically illustrate a fuel system in a motor vehicle with a pump device in different configurations according to the present invention; Fig. 3a-b schematically illustrate a cross-sectional view of a pump device in different configurations according to one embodiment of the present invention; and

Fig. 4a-b schematically illustrate a cross-sectional view of a pump device in different configurations according to one alternative embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

Fig. 1 schematically illustrates a motor vehicle 1 according to an embodiment of the present invention. The exemplified vehicle 1 consists of a heavy goods vehicle in the form of a truck. The vehicle may consist of any suitable vehicle, such as a bus, a passenger car, a working vehicle, a military vehicle or similar. The vehicle comprises a pump device according to the present invention. The vehicle comprises a combustion engine 30. The invention may also be applied to a free-standing engine e.g. in a power plant or on a ship, however, no such embodiment is shown.

Fig. 2a-b illustrate schematically a fuel system I in an engine comprising a pump device 10 arranged for manual pumping according to the present invention.

The fuel system I comprises a fuel tank 20 from which fuel F is arranged to be pumped to the combustion engine 30. The fuel system I also comprises a return pipe L to lead back superfluous fuel F from the engine 30 back to the fuel tank 20.

The fuel system I also comprises a fuel filter configuration 40 to filter from the fuel tank 20 pumped fuel F before the fuel F is led to the engine 30. The fuel configuration 40 comprises, according to this embodiment, a first filter device 42 for pre-filtration of the fuel F and a second filter device 44 for filtration of the pre-filtered fuel F in order to obtain as clean a fuel F as possible in the engine 30. The respective filter devices 42, 44 of the fuel filter configuration 40 comprise an evacuation pipe 42a, 44a, connected to the return pipe L, for evacuation of fuel F from a filter housing in the respective filter devices 42, 44 upon a filter replacement.

The fuel system I further comprises a feeding pump 50 driven by the engine 30, arranged to pump fuel F during operation to the engine 30. The feeding pump 50 is arranged between the first filter device 42 and the second filter device 44.

The fuel system I also comprises a high pressure pump 60 for increase of the pressure of the fuel F before the fuel F is injected into the engine 30 via an injection device (not shown).

The fuel system I also comprises the said pump device 10 arranged for manual pumping according to the present invention. The pump device 10 is designed for manual pumping and, accordingly, consists of a manual pump device.

The pump device 10 is arranged for manual pumping of fuel from the fuel tank 20 via the fuel filter configuration 40 to the vehicle's engine 30 and for manual evacuation of remaining fuel F from the filter configuration.

Fig. 2a illustrates schematically the manual pump device 10 in a first mode in which the pump device 10 is arranged for manual pumping of fuel F from the fuel tank 20 to the vehicle's engine 30. In the first mode, the pump device 10 is arranged accordingly, so that the fuel F is pumped with the pump device 10 from the fuel tank 20 in a pipe L1 a via the pump device 10 and from the pump device via the first and second filter devices 40, 42 in the fuel filter configuration 40 and further to the engine 30. Fig. 2b illustrates schematically the manual pump device 10 in a second mode in which the pump device 10 is arranged for manual suction of fuel F from the said fuel filter configuration 40 for the said evacuation. Thus, the fuel F is sucked from the evacuation pipe 42a in the first filter device 42 and the evacuation pipe 44a in the second filter device 44 and via the pump device 10 and from the pump device in a pipe L2b to the fuel tank 20.

According to an embodiment not shown, the pipe L1 a from which fuel is pumped in the said first mode and the pipe L2b which sucks fuel to the fuel tank in the said second mode constitute the same pipe.

The pump device 10 is manually adjustable between the said first mode and second mode.

Fig. 3a-b schematically illustrate a cross-sectional view of a pump device 100 in different modes according to one embodiment of the present invention.

The pump device 100, according to this embodiment, comprises a pump cylinder 1 10 with a piston configuration 120 for manual pumping and evacuation. The pump device 100 comprises a first space 1 12 arranged in the pump cylinder 1 10 via which fuel F is arranged to be pumped from the said fuel tank 20 and a second space 1 14 arranged in the pump cylinder 1 10 via which fuel from the fuel filter configuration 40 is arranged to be evacuated. The fuel F is here arranged to be evacuated from the said fuel filter configuration 40 to the fuel tank 20.

The said first and second spaces 1 12, 1 14 are delimited with a substantially horizontal wall section 1 10a. The piston configuration 120 comprises a piston rod 125, a piston element 122 connected to the piston rod 125, and a piston handle 126 connected to the piston rod 125 for the said manual pumping. The piston configuration 120 is arranged in the first space for a piston stroke in connection with pumping, so that the piston rod 125 runs in the pump cylinder's 1 10 axial direction, and so that the piston element 122 is arranged to operate in the first space 1 12 for the said pumping/evacuation.

The pump device 100 also comprises a spring element 130 arranged around the piston rod 125 between the piston element 122 and the lower wall section 1 10a adjacent to the second space 1 14 to, upon a compression load, operate against the piston element 122, so that the piston element 122 springs back to its original position in connection with pumping.

Fig. 3a illustrates schematically the manual pump device 100 in a first mode in which the pump device 100 is arranged for manual pumping of fuel F from the fuel tank 20 in a pipe L1 a via the first space 1 12 and in a pipe L1 b to the fuel filter configuration 40 and via the fuel filter configuration 40 to the engine 30 (not shown in figure 3a). In the first mode, the pump device 100 is arranged accordingly to facilitate the fuel flow through the first space 1 12, i.e. so that the fuel F with the piston configuration 120 of the pump device 100 is pumped from the fuel tank 20 inside a pipe via the first space 1 12 of the pump device 100.

Fig. 3b illustrates schematically the manual pump device 100 in a second mode in which the pump device 100 is arranged for manual suction of fuel F from the said fuel filter configuration 40 in an evacuation pipe L2a via the second space 1 14 and in a pipe L2b to the fuel tank 20 for the said evacuation. In the second mode, the pump device 100 is arranged accordingly to facilitate the fuel flow through the second space 1 14, i.e. so that the fuel F with the piston configuration 120 is sucked from an evacuation pipe of the fuel filter configuration 40 via the second space 1 14 of the pump device 100 to the fuel tank 20. The pump cylinder 1 10 comprises a first inlet opening 1 12a in the first space 1 12, at which a first inlet valve 142a in the form of a check valve is arranged. The first inlet valve 142a is arranged in the first mode to allow fuel F from the fuel tank 20 to be pumped into the first space 1 12. The pump cylinder 1 10 comprises a first outlet opening 1 12b arranged in the first space 1 12, at which a first outlet valve 142b in the form of a check valve is arranged. The first outlet valve 142b is arranged in the first mode to allow fuel F from the fuel tank 20 to be pumped out of the first space 1 12.

The pump cylinder 1 10 comprises a second inlet opening 1 14a arranged in the second space, at which a second inlet valve 144a in the form of a check valve is arranged. The second inlet valve 144a is arranged to allow fuel F in the second mode, evacuated from the fuel filter configuration 40, to be sucked into the second space 1 14.

The pump cylinder 1 10 comprises a second outlet opening 1 14b arranged in the second space 1 14, at which a second outlet valve 144b in the form of a check valve is arranged. The second outlet valve 144b is arranged in the second mode to allow fuel F from the fuel filter configuration 40 to be pumped out of the second space 1 14.

The said pump cylinder 1 10 comprises an insert 150 rotatably arranged in the pump cylinder 1 10 around the cylinder's central shaft X, which in the said first mode is arranged to facilitate fuel flow through the first space 1 12, and in the second mode is arranged to facilitate fuel flow through the second space 1 14. .

The pump device 100 comprises a manoeuvring element 160 connected with the said insert 150 for manual shifting of the said insert 150 between the said first mode and the said second mode. According to one variant, the said insert 150 is arranged to be rotated 180 degrees for shifting between the first and the second modes. The pump device 100 comprises a first sealing element 01 arranged in connection with the first inlet opening 1 12a to operate as a sealant toward the said insert 150. The pump device 100 comprises a second sealing element 02 arranged in connection with the first outlet opening 1 12b to operate as a sealant toward the said insert 150.

The pump cylinder 1 10 comprises a connecting opening 1 13 between the said first space 1 12 and the second space 1 14. The pump device 100 comprises a third sealing element 03 arranged in connection with the connecting opening to operate as a sealant toward the said insert 150. The pump device 100 comprises a fourth sealing element 04 arranged in connection with the piston element's 122 periphery to operate as a sealant toward the said insert 150.

The said insert 150 is rotatably arranged in the first space 1 12. The said insert 150 has a first opening 152a arranged at the height of the first inlet opening 1 12a and a second opening 152b arranged at the height of the second outlet opening 1 12b.

The said insert 150 is in the first mode turned in a position so that the said first opening 152a is brought in line with the said first inlet opening 1 12a, and the said second opening 152b is brought in line with the said second outlet opening 1 12b, so that the fuel F may be pumped from the fuel tank 20 and through the said first space 1 12. In the first mode, fuel flow is thus facilitated through the first space 1 12 because the insert's 150 first inlet opening 152a is brought in line with the pump cylinder's 1 10 first inlet opening 1 12a, and the insert's 150 first outlet opening 152b is brought in line with the pump cylinder's 1 10 first outlet opening 1 12b.

The said insert 150 is in the second mode turned in a position so that the said first opening 152a is brought in line with the said first inlet opening 1 12a, and the said second opening 152b is brought out of line with the said second outlet opening 1 12b, so that the fuel F may not be pumped from the fuel tank 20 and through the said first space 1 12.

The said first inlet opening 1 12a and the first outlet opening 1 12b are here arranged at different height levels of the pump cylinder 1 10 so that, when the insert 150 is turned according to the first mode, the first and the second openings 152a, 152b of the insert 150 are brought in line with the first inlet opening 1 12a and the first outlet opening 1 12b in the first space 1 12, and when the insert is turned according to the second mode, the first and the second openings 152a, 152b of the insert 150 are brought to separate from the first inlet opening 1 12a and the first outlet opening 1 12b in the first space 1 12.

The said insert 150 also comprises a third opening 153 arranged in the first mode to be positioned so that no flow is allowed through the connecting opening 1 13 and, accordingly, no flow is permitted between the first space 1 12 and the second space 1 14. The insert 150 is arranged accordingly in the first mode to block the connecting opening 1 13 in order to prevent flow between the first and the second spaces 1 12, 1 14 and thus also the pumping action in the second space 1 14.

The third opening 153 of the insert 150 is arranged in the second mode to be positioned so that the third opening 153 is brought in line with the connecting opening 1 13 between the first space 1 12 and the second space 1 14, so that flow is allowed through the third opening 1 13 and, accordingly, flow is allowed between the first space 1 12 and the second space 1 14, so that the pumping action is facilitated in the second space 1 14. The insert 150 is arranged accordingly in the second configuration to open the connecting opening 1 13 in order to facilitate the flow of fuel between the first 1 12 and the second space 1 14.

In the second mode, fuel F is sucked from the fuel filter configuration 40 through manual pumping with the piston configuration 120, so that flow is allowed through the connecting opening 1 13, with the piston configuration 120 for evacuation of fuel F from the fuel filter configuration 40 via the second space 1 14 to the fuel tank 20.

Fig. 4a-b schematically illustrate a cross-sectional view of a pump device 200 in different modes according to one alternative embodiment of the present invention.

The pump device 200, according to this embodiment, differs from the embodiment according to Fig. 3a-b because of the design of the piston configuration 220, where shifting between the first and second modes occurs through rotation of the piston configuration 220 and where, accordingly, no insert in the pump cylinder 210 as in Fig. 3a-b is required.

The pump device 200, according to this embodiment, comprises a pump cylinder 210 with a piston configuration 220 for manual pumping and evacuation. The pump device 200 comprises a first space 212 arranged in the pump cylinder 210, via which fuel F is arranged to be pumped from the said fuel tank 20, and a second space 214 arranged in the pump cylinder 210, via which the fuel filter configuration 40 is arranged to be evacuated, where fuel F according to this embodiment is arranged to be sucked from the said fuel filter configuration 40 via the said second space 214 to the fuel tank 20 for the said evacuation.

The pump cylinder 210 comprises a first inlet opening 212a arranged in the first space 212, at which a first inlet valve 242a in the form of a check valve is arranged, and a first outlet opening 212b, at which a first outlet valve 242b in the form of a check valve is arranged to facilitate fuel flow through the first space 212 in the first mode. According to this embodiment, the first inlet opening 212a and the first outlet opening 21 2b are arranged at substantially the same level.

The pump cylinder 210 also comprises a second inlet opening 214a arranged in the second space 214, at which a second inlet valve 244a in the form of a check valve is arranged, and a second outlet opening 214b, at which a second outlet valve 244b in the form of a check valve is arranged in order to facilitate fuel flow in the second mode through the second space 214.

The piston configuration 220 comprises a piston rod 225 and a piston handle 226 connected with the piston rod for the said manual pumping. The piston configuration 220 comprises two piston elements 222, 224, where the first piston element 222 is arranged to operate in the first space 212 and the second piston element 224 is arranged to operate in the said second space 214. The piston elements 222, 224 are arranged to facilitate transmission alternately by rotation of the piston configuration 220 around the said cylinder's 210 central shaft X. Figures 4a-4b show that the transmission is facilitated by the piston elements 222, 224 alternately being brought into engagement with the piston rod 225. Thus, the said piston elements 222, 224 are arranged alternately to be brought into engagement with the piston rod 225 through rotation of the piston configuration 220, e.g. with the piston handle 226.

The piston rod 225 is arranged to run in the pump cylinder's 210 axial direction X through the first space 212 and into the second space 214 via an opening between the first and the second spaces 212, 214. The first piston element 222 is arranged on the piston rod 225 in the first space 212 and the second piston element 224 is arranged on the piston rod 225 in the second space 214. The pump device 200 comprises a first sealing element 05 arranged in connection with the opening to operate as a sealant toward the said piston rod. The pump device 200 also comprises a second sealing element O6 arranged in connection with an upper opening of the pump cylinder 210 to operate as a sealant toward the said piston rod.

The respective piston element is rotatably and slidably arranged at the piston rod 225. The first piston element 222 and the second piston element 224 are connected with the piston rod 225 in such a manner that in the first mode the first piston element 222 is brought into engagement with the piston rod 225, so that it follows the movement of the piston rod 225, and the second piston element 224 is disconnected from the piston rod 225, so that the piston rod 225 is allowed to run in relation to the second piston element 224.

The first piston element 222 is arranged accordingly in the first space 212 for a piston stroke when pumping according to the first mode, and the second piston element 224 is arranged in the second space 214 for a piston stroke when pumping according to the second mode.

Further, in the second mode, the second piston element 224 is brought into engagement with the piston rod 225, so that it follows through the piston rod's 225 movement, and the first piston element 222 is disconnected from the piston rod 225, so that the piston rod 225 is allowed to run in relation to the first piston element 222. Shifting between the first mode and the second mode occurs by rotating the piston configuration 220.

The respective piston elements 222, 224 comprise a piston section 222a, 224a in order for pumping/suction to operate in the respective space, and a circular sleeve section 222b, 224b connected with the piston section arranged to protrude from the piston section and to, enveloping, run along the piston rod 225.

The sleeve section 222b, 224b of the respective piston elements 222, 224 comprise a pervading L-shaped track G1 , G2 with a substantially horizontal track section G1 a, G2a arranged to run circumferentially along a part of the lateral surface in the upper section of the sleeve section 222b, 224b and a substantially vertical track section G1 b, G2b running along the sleeve section from the horizontal track section G1 a, G2a. The pump device 200 also comprises a first engagement element 225a on the piston rod 225 in connection with the first piston element 222, and a second engagement element 225b arranged in connection with the second piston element 224. The first and the second engagement elements 225a, 225b are arranged to fit and be allowed to run in the track G1 , G2 of the respective sleeve sections 222b, 224b. The first and second engagement elements 225a, 225b are arranged so that, in relation to the first and second piston elements 222, 224, the first engagement section 225a is brought into engagement by existing in the horizontal track section G1 a of the first piston element 222, the second engagement section 225b is arranged in the vertical track section G2b, so that the piston rod 225 is permitted to run relative to the second piston element 224 in connection with axial movement of the piston rod 225. Further, the first and second engagement elements 225a, 225b are arranged in relation to the first and second piston elements 222, 224, so that when the second engagement section 225b is brought into engagement by existing in the horizontal track section G2a of the second piston element 224, the first engagement section 225a is arranged in the vertical track section G1 b so that the piston rod 225 is permitted to run in relation to the first piston element 222 on an axial movement of the piston rod 225.

The first and the second piston elements 222, 224 are arranged to alternately be brought in engagement by rotation around the said piston rod's 225 axial direction with the piston handle 226. Thus, only the said first piston element 222 is brought into engagement with the piston rod 225 in the said first mode in order to facilitate fuel flowing through the first space 212, and only the said second piston element 224 brought into engagement with the piston rod 225 in the said second mode to facilitate fuel flow through the second space 214.

The respective engagement sections 225a, 225b are, according to one variant, designed as spigot-like projections.

The pump device 200 also comprises a spring element 232, 234 arranged around the piston rod 225 in connection with the respective piston element to operate against the piston elements 222, 224 on a compression load, so that, in connection with pumping, the piston element brought into engagement springs back to its original position. The pump device 200 comprises sealing elements 04a, O4b arranged in connection with the periphery of the respective piston elements 222, 224 in order to operate as a sealant toward the said cylinder 210.

The foregoing description of the preferred embodiments of the present invention has been furnished for illustrative and descriptive purposes. It is not intended to be exhaustive, or to limit the invention to the variants described. Many modifications and variations will obviously be apparent to one skilled in the art. The embodiments have been chosen and described in order to best explicate the principles of the invention and its practical applications, and to thereby enable one skilled in the art to understand the invention in terms of its various embodiments and with the various modifications that are applicable to its intended use.