A working machine

Abstract

A working machine (10,fig.1) comprising an engine (24,fig.1), fuel reservoir (26,fig.2) and fuel line (28a,28b,fig.2) connecting the fuel reservoir to the engine. The working machine comprises an addi

Description

FIELD This invention relates to a working machine and to an additive dosing system for a working machine. BACKGROUND Off-highway vehicles / working machines are typically those used in construction industries (e.g. backhoe loaders, slew excavators, telescopic handlers, forklifts, skid-steer loaders, dump trucks, bulldozers, graders), agricultural industries (e.g. tractors, combine harvesters, wheeled loading shovels, telescopic handlers, self-propelled harvesters and sprayers), quarrying (e.g. excavators, wheeled loading shovels, aggregate crushing equipment), and forestry (e.g. timber harvesters, feller bunchers). Many working machines have a primary function of moving material using either a lifting arm (e.g. a pivoting boom) or a working arm (e.g. an excavator arm) and may be referred to as material handling machines. Conventionally, working machines of the type referred to above are generally powered by diesel internal combustion engines. During operation of the engine system, components of the engine system such as fuel injectors may begin to operate with reduced fuel efficiency, for example by becoming blocked, fouled or stuck in an open or closed position. The reduced efficiency of the fuel injectors may be caused by evaporation of fuel left on the fuel injectors, which can leave behind deposits inside the fuel injector. This can lead to an uneven distribution of fuel into the engine and damage of components in the engine system, for example and engine and / or aftertreatment system. In cases where the fuel injectors have become blocked or stuck, the engine system may need servicing in order for the working machine to be operable. This process can be time consuming and costly, and the working machine is unable to operate during servicing. The present teachings seek to overcome or at least mitigate one or more problems associated with the prior art. SUMMARY The present teachings provide a working machine according to the appended claims. According to a first aspect of the present teachings, there is provided a working machine. The working machine may comprise: a ground engaging propulsion structure; a body supported by the ground engaging propulsion structure. The working machine may comprise an engine system. The engine system may comprise: an engine configured to provide motive power to the ground engaging propulsion structure; a fuel reservoir; a fuel line fluidly connecting the fuel reservoir and the engine; and an additive dosing system. The additive dosing system may comprise an additive reservoir, and an additive supply line fluidly connecting the additive reservoir to the fuel line and / or to the fuel reservoir for supplying additive to the fuel line and / or to the fuel reservoir. The additive dosing system may be configured to automatically supply a predetermined volume of additive to the fuel line and / or to the fuel reservoir. During operation of the engine system, components of the engine system such as fuel injectors may become blocked, fouled or stuck in an open or closed position, in particular where fuel quality is poor. This can lead to an uneven distribution of fuel into the engine and damage of components in the engine system, for example and engine and / or aftertreatment system. In cases where the fuel injectors have become blocked or stuck, the engine system may need servicing in order for the working machine to be operable. This process can be time consuming and costly, and the working machine is unable to operate during servicing. Automatically supplying additive to the engine system helps to prevent malfunction of components in the engine system such as fuel injectors, and reduces the likelihood of the engine system needing servicing. In addition, the automation of supply reduces the reliance on the operator to add additive to the engine system, and reduces the level of manual labour involved with maintenance of the engine system. The working machine may comprise a control system configured to determine a fuel level of fuel in the fuel reservoir. The predetermined volume of additive may be based on the fuel level. Advantageously, the predetermined volume can be increased or decreased depending on the fuel level in the engine system to ensure the correct amount of additive is added to the fuel. As such, the concentration of additive in the fuel can be kept at an optimal level for cleaning components of the engine system. The predetermined volume may be proportional to the fuel level of fuel in the fuel reservoir. The control system may be configured to supply the predetermined volume of additive when it is determined that refuelling of the fuel reservoir has occurred. The predetermined volume may be predetermined volume is proportional to the fuel level of fuel in the fuel reservoir after refuelling has occurred. A ratio of the predetermined volume of additive supplied to the fuel line and / or the fuel reservoir to the fuel level of fuel in the fuel reservoir may be in the range 0.01:1 to 0.0001:1, optionally in the range 0.005:1 to 0.0005:1, for example approximately 0.001:1. Advantageously, ratios within these ranges have been found to provide a concentration of additive in the fuel at an optimal level for cleaning components of the engine system. The control system may be configured to overdose the fuel with additive by a predetermined amount to achieve a predetermined concentration of additive in the fuel reservoir when fuel is returned from the engine to the fuel reservoir. Advantageously, overdosing helps to ensure there is sufficient additive remaining in the fuel mixture to clean the fuel injectors. The predetermined amount may be determined based on a difference between a volume of fuel supplied to the engine and a volume of fuel returned to the fuel reservoir. Advantageously, overdosing helps to ensure there is sufficient additive remaining in the fuel mixture to clean the fuel injectors. The additive dosing system may comprise a valve arrangement on the additive supply line. The valve arrangement may be configured to control the supply of additive to the fuel line and / or to the fuel reservoir of the engine system. Advantageously, providing a valve arrangement enables selective supply of additive to the fuel line and / or to the fuel reservoir. Valves are reliable and simple to integrate with existing controllers of the working machine. The valve arrangement may be moveable between an open position and a closed position. The valve arrangement may be moved into the open position for a predetermined time to supply the predetermined volume of additive to the fuel line and / or to the fuel reservoir. Advantageously, opening the valve arrangement for a predetermined time is a simple way of supplying the predetermined volume of additive to the fuel line without the need for complex sensors. The valve arrangement may comprise a solenoid valve configured to control the supply of additive to the fuel line and / or to the fuel reservoir. Advantageously, solenoid valves are reliable and can be integrated into existing control systems on the working machine. The dosing module may be configured to periodically supply additive from the additive reservoir to the fuel line and / or the fuel reservoir of the engine system at predetermined time intervals. Advantageously, the predetermined time interval can be determined so that the concentration of additive in the fuel can be kept at an optimal level for cleaning components of the engine system. The control system may be configured to determine a fuel level of fuel in the fuel reservoir. The predetermined time interval may be based on the determined fuel level. Advantageously, the predetermined time interval can be increased or decreased depending on fuel level of fuel in the fuel reservoir. As such, the concentration of additive in the fuel can be kept at an optimal level for cleaning components of the engine system. The predetermined time interval may be in the range 400 hours to 600 hours, optionally in the range 450 hours to 550 hours. Advantageously, time intervals within these ranges have been found to provide a concentration of additive in the fuel at an optimal level for cleaning components of the engine system. The control system may be configured to determine an additive level of additive in the additive reservoir, wherein the control system is configured to produce an alert when it is determined that the additive level is below a predetermined additive threshold. Advantageously, the alert enables the operator to refill the additive reservoir with additive so that there is a supply of additive available for the dosing operation. The control system may be configured to determine an additive level of additive in the additive reservoir. The additive dosing system may be configured to automatically supply the predetermined volume only when it is determined that the additive level is above a predetermined additive threshold. Advantageously, this enables there to be a sufficient supply of additive available for optimal dosing of additive. The control system may be configured to determine the engine speed of the engine, wherein the additive dosing system is configured to automatically supply additive from the additive reservoir to the fuel line and / or to the fuel reservoir of the engine system only when it is determined that the engine system is in an active state, optionally when an engine speed of the engine is above a predetermined engine speed threshold. Advantageously, this helps to ensure good mixing of the additive with the fuel. The additive reservoir may be located above the additive outlet of the additive supply line, in use, such that additive is supplied under gravity to the additive outlet via the additive supply line. Advantageously, this arrangement enables the supply of additive to the fuel line and / or to the fuel reservoir without the need for complex pipework or pumps. The fuel line may comprise a fuel supply line configured to supply fuel from the fuel reservoir to the engine and a fuel return line configured to return fuel from the engine to the fuel reservoir, and the additive supply line may be connected to the fuel supply line. Advantageously, connecting the additive dosing system to the fuel supply line enables mixing of the additive into the fuel so that additive is circulated around the fuel line and to the fuel injectors. The additive supply line may be connected to the fuel reservoir. The engine system may comprise a pump configured to transport fuel between the fuel reservoir and the engine. The additive supply line may be connected to the fuel supply line upstream of the pump. Advantageously, this arrangement enables the pump to draw additive from the additive reservoir and into the fuel line and / or to the fuel reservoir of the engine system to facilitate supply of additive to the fuel line and / or to the fuel reservoir without the need for complex pipework or pumps. This increases simplicity and compactness of the additive dosing system. The additive dosing system may comprise an additive pump configured to transport additive from the additive reservoir to the fuel supply line or fuel reservoir. The additive reservoir may be located in a housing comprising an additive inlet. The additive inlet may comprise a cap removably mounted thereto. The additive may be a detergent, optionally a surfactant, a volatile component or a mixture thereof. According to a further aspect of the present teachings, there is provided an additive dosing system for a working machine. The additive dosing system may comprise: an additive reservoir; an additive supply line configured to connect the additive reservoir to a fuel line and / or to a fuel reservoir of the working machine for supplying additive to the fuel line and / or to the fuel reservoir; and / or a valve arrangement on the additive supply line and moveable between an open position and a closed position. The valve arrangement may be configured to be moved into the open position for a predetermined time to supply a predetermined volume of additive through the additive supply line. During operation of the engine system, components of the engine system such as fuel injectors may become blocked, fouled or stuck in an open or closed position, in particular where fuel quality is poor. This can lead to an uneven distribution of fuel into the engine and damage of components in the engine system, for example and engine and / or aftertreatment system. In cases where the fuel injectors have become blocked or stuck, the engine system may need servicing in order for the working machine to be operable. This process can be time consuming and costly, and the working machine is unable to operate during servicing. Automatically supplying additive to the engine system helps to prevent malfunction of components in the engine system such as fuel injectors, and reduces the likelihood of the engine system needing servicing. In addition, the automation of supply reduces the reliance on the operator to add additive to the engine system, and reduces the level of manual labour involved with maintenance of the engine system. The additive dosing system may be connectable to a control system configured to determine a fuel level of fuel in the fuel reservoir. The predetermined volume of additive may be based on the fuel level. Advantageously, the predetermined volume can be increased or decreased depending on the fuel level in the engine system to ensure the correct amount of additive is added to the fuel. As such, the concentration of additive in the fuel can be kept at an optimal level for cleaning components of the engine system. The predetermined volume may be proportional to the fuel level of fuel in the fuel reservoir. The additive dosing module may be connectable to a control system. The control system may be configured to supply the predetermined volume of additive when it is determined that refuelling of the fuel reservoir has occurred. The predetermined volume may be predetermined volume is proportional to the fuel level of fuel in the fuel reservoir after refuelling has occurred. A ratio of the predetermined volume of additive supplied to the fuel line and / or the fuel reservoir to the fuel level of fuel in the fuel reservoir may be in the range 0.01:1 to 0.0001:1, optionally in the range 0.005:1 to 0.0005:1, for example approximately 0.001:1. Advantageously, ratios within these ranges have been found to provide a concentration of additive in the fuel at an optimal level for cleaning components of the engine system. The additive dosing module may be connectable to a control system. The control system may be configured to overdose the fuel with additive by a predetermined amount to achieve a predetermined concentration of additive in the fuel reservoir when fuel is returned from the engine to the fuel reservoir. Advantageously, overdosing helps to ensure there is sufficient additive remaining in the fuel mixture to clean the fuel injectors. The predetermined amount may be determined based on a difference between a volume of fuel supplied to the engine and a volume of fuel returned to the fuel reservoir. Advantageously, overdosing helps to ensure there is sufficient additive remaining in the fuel mixture to clean the fuel injectors. The additive dosing system may comprise a valve arrangement on the additive supply line. The valve arrangement may be configured to control the supply of additive to the fuel line and / or to the fuel reservoir of the engine system. Advantageously, providing a valve arrangement enables selective supply of additive to the fuel line and / or to the fuel reservoir. Valves are reliable and simple to integrate with existing controllers of the working machine. The valve arrangement may be moveable between an open position and a closed position. The valve arrangement may be moved into the open position for a predetermined time to supply the predetermined volume of additive to the fuel line and / or to the fuel reservoir. Advantageously, opening the valve arrangement for a predetermined time is a simple way of supplying the predetermined volume of additive to the fuel line without the need for complex sensors. The valve arrangement may comprise a solenoid valve configured to control the supply of additive to the fuel line and / or to the fuel reservoir. Advantageously, solenoid valves are reliable and can be integrated into existing control systems on the working machine. The dosing module may be configured to periodically supply additive from the additive reservoir to the fuel line and / or the fuel reservoir of the engine system at predetermined time intervals. Advantageously, the predetermined time interval can be determined so that the concentration of additive in the fuel can be kept at an optimal level for cleaning components of the engine system. The additive dosing module may be connectable to a control system. The control system may be configured to determine a fuel level of fuel in the fuel reservoir. The predetermined time interval may be based on the determined fuel level. Advantageously, the predetermined time interval can be increased or decreased depending on fuel level of fuel in the fuel reservoir. As such, the concentration of additive in the fuel can be kept at an optimal level for cleaning components of the engine system. The predetermined time interval may be in the range 400 hours to 600 hours, optionally in the range 450 hours to 550 hours. Advantageously, time intervals within these ranges have been found to provide a concentration of additive in the fuel at an optimal level for cleaning components of the engine system. The additive dosing module may be connectable to a control system. The control system may be configured to determine an additive level of additive in the additive reservoir, wherein the control system is configured to produce an alert when it is determined that the additive level is below a predetermined additive threshold. Advantageously, the alert enables the operator to refill the additive reservoir with additive so that there is a supply of additive available for the dosing operation. The additive dosing module may be connectable to a control system. The control system may be configured to determine an additive level of additive in the additive reservoir. The additive dosing system may be configured to automatically supply the predetermined volume only when it is determined that the additive level is above a predetermined additive threshold. Advantageously, this enables there to be a sufficient supply of additive available for optimal dosing of additive. The additive dosing module may be connectable to a control system. The control system may be configured to determine the engine speed of the engine, wherein the additive dosing system is configured to automatically supply additive from the additive reservoir to the fuel line and / or to the fuel reservoir of the engine system only when it is determined that the engine system is in an active state, optionally when an engine speed of the engine is above a predetermined engine speed threshold. Advantageously, this helps to ensure good mixing of the additive with the fuel. The additive reservoir may be located above the additive outlet of the additive supply line, in use, such that additive is supplied under gravity to the additive outlet via the additive supply line. Advantageously, this arrangement enables the supply of additive to the fuel line and / or to the fuel reservoir without the need for complex pipework or pumps. The additive supply line may be configured to be connected to the fuel reservoir. The additive supply line may be configured to be connected to the fuel supply line upstream of the pump. Advantageously, this arrangement enables the pump to draw additive from the additive reservoir and into the fuel line and / or to the fuel reservoir of the engine system to facilitate supply of additive to the fuel line and / or to the fuel reservoir without the need for complex pipework or pumps. This increases simplicity and compactness of the additive dosing system. The additive dosing system may comprise an additive pump configured to transport additive from the additive reservoir to the fuel supply line or fuel reservoir. The additive reservoir may be located in a housing comprising an additive inlet. The additive inlet may comprise a cap removably mounted thereto. The additive may be a detergent, optionally a surfactant, a volatile component or a mixture thereof. The skilled person will appreciate that except where mutually exclusive, a feature described in relation to any one of the aspects, embodiments or examples described herein may be applied mutatis mutandis to any other aspect, embodiment or example. Furthermore, except where mutually exclusive, any feature described herein may be applied to any aspect and / or combined with any other feature described herein. BRIEF DESCRIPTION OF DRAWINGS Embodiments will now be described by way of example only with reference to the accompanying figures, in which: Figure 1 is a side view of a working machine according to an embodiment of the present teachings; Figure 2 is a schematic view of an engine system of the working machine of Figure 1; Figure 3 is a perspective view of an additive dosing system of the working machine of Figure 1 according to an embodiment of the present teachings; Figure 4 is a block diagram of a control system for controlling the dosing module of Figure 3; and Figure 5 is a flow chart illustrating the control logic for controlling the additive dosing system of Figure 3. DETAILED DESCRIPTION OF EMBODIMENT(S) In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of various embodiments and the inventive concept. However, those skilled in the art will understand that: the present invention may be practiced without these specific details or with known equivalents of these specific details; that the present invention is not limited to the described embodiments; and, that the present invention may be practiced in a variety of alternative embodiments. It will also be appreciated that well known methods, procedures, components, and systems may have not been described in detail. References to vertical and horizontal in the present disclosure should be understood to be in relation to the machine when stood on horizontal ground in a non-working condition. The term axial is generally used in relation to the longitudinal axis of the machine. The term width is generally used in relation to the longitudinal length, that is, transverse to the length. Referring firstly to Figure 1, there is illustrated a working machine 10 according to an embodiment of the present teachings. In the present embodiment, the working machine is a wheeled excavator, but in alternative embodiments, the working machine 10 may be a backhoe loader, telehandler, tractor, rotary telehandler, loading shovel or the like. The working machine 10 includes a body. The body includes an undercarriage 12 and a superstructure 14 mounted to the undercarriage 12. The working machine 10 includes an operator structure 16 from which an operator is able to operate the working machine 10. In some arrangements, the working machine 10 may not include an undercarriage 12 and superstructure 14 and instead may include an operator structure 16 mounted onto the body or a chassis. In the illustrated embodiment, the superstructure 14 is rotatably mounted to the undercarriage 12, and the operator structure 16 is rotatably mounted to the superstructure 14. In alternative arrangements of the working machine 10, it will be appreciated that the operator structure 16 may not be rotatable relative to the superstructure 14 and / or that the superstructure 14 may not be rotatable relative to the undercarriage 12. A working arm 18 is rotatably mounted to the superstructure 14 for performing working operations. The working arm 18 is mounted via kingpost arrangement 21. The working arm 18 has a working implement 19 mounted at the distal end thereof. In the illustrated embodiment, the working implement 19 is a bucket, but in alternative arrangements any suitable working implement may be used such as forks, a shovel, a sweeper, a grapple etc. The undercarriage 12 is connected to a ground engaging structure. The ground engaging structure includes wheels 22a, 22b. The wheels 22a, 22b are mounted to the undercarriage 12 via first and second drive axle assemblies. The second drive axle assembly is fixed with respect to the undercarriage 12, whereas the first drive axle assembly is capable of limited articulation, thereby permitting the wheels to remain in ground contact, even if the ground is uneven. The wheels 22a, 22b are typically provided with off-road pneumatic tyres. In this embodiment, both drive axle assemblies are steer axles, but this may not always be the case. In alternative arrangements, the ground engaging structure may include a pair of endless tracks. The working machine 10 includes an engine system 20, illustrated in Figure 2. The engine system 20 includes a prime mover 24, a fuel reservoir 26 and a fuel line 28a, 28b. The prime mover 24 is provided in the form of a diesel internal combustion engine 24. It shall be appreciated that in alternative embodiments, the prime mover 24 may be an alternative engine. The engine 24 is configured to provide motive power to the ground engaging structure 22a, 22b. The engine 24 is mounted to the undercarriage 12. In some embodiments, a cooling arrangement 36, for example including a heat exchanger and / or a cooling fan are housed in the undercarriage 12 adjacent the engine 24. The fuel reservoir 26 is a fuel tank 26. The fuel reservoir 26 provides a fuel supply to the engine 24 and may be positioned on an opposite side of undercarriage to the engine 24, or in any suitable location. The fuel line 28a, 28b fluidly connects the fuel reservoir 26 and the engine 24. As illustrated in Figure 2, the fuel line 28a, 28b may include a fuel supply line 28a and a fuel return line 28b. The fuel supply line 28a is configured to supply fuel from the fuel reservoir 26 to the engine 24. The fuel return line 28b is configured to return fuel from the engine 24 to the fuel reservoir 26. The engine system 48 includes a pump arrangement 30 configured to transport fuel between the fuel reservoir 26 and the engine 24. In the embodiment shown in Figure 2, the pump arrangement 30 includes a low-pressure fuel supply pump 40 for transferring fuel from the fuel tank 26 through the fuel supply line 28a. The pump arrangement 30 also includes a high-pressure pump 42 for supplying fuel to the engine 24. The pump arrangement 30 includes a primary filter 44 and a secondary filter 46. The primary filter 44 is located downstream of the low-pressure pump 40. The secondary filter 46 is located between the low-pressure pump 40 and the high-pressure pump 42 (i.e. downstream of the high-pressure pump 42 and upstream of the low-pressure pump 40). It shall be appreciated that in alternative embodiments, any suitable pump arrangement 30 may be used. For example, only one pump 40, 42 may be provide, or more than two pumps 40, 42 may be provided. The primary and / or secondary filters 44, 46 may be omitted, or may be provided at an alternative location in the engine system 20. The engine system 20 includes a plurality of fuel injectors 32 configured to supply fuel to the engine 24. The fuel injectors 32 may be electromagnetic solenoid valves which are controlled by the control system 66 of the working machine 10, as is known in the art. In the embodiment shown in Figure 3, four fuel injectors 32 are provided, however in alternative embodiments any suitable number of fuel injectors 32 may be provided. The fuel injectors 32 are connected in series along a fuel rail 34. The fuel rail 34 move between a closed position and an open position in which high-pressure fuel is distributed to the fuel injectors 32. As such, fuel is pumped by the pump arrangement 30 from the fuel reservoir 26, into the fuel supply line 28a through the fuel rail 34 and to the engine 24 via the fuel injectors 32. In use, heat from the engine 24 may cause fuel left in the fuel injectors 32 to evaporate, leaving behind deposits inside the fuel injector 32. Over time, these deposits may lead to blocking of the fuel injector 32, or the fuel injector 32 becoming stuck in the open or closed position. This is particular problem where fuel quality is poor. The blocking and / or sticking of the fuel injectors 32 can lead to an uneven distribution of fuel into the engine 24, which may cause engine misfire and a decrease in fuel efficiency of the engine system 20. In some cases, this can result in damage of components of the engine system 20, for example the engine 24 and / or the aftertreatment system. In cases where the fuel injectors 32 have become blocked or stuck, the engine system 20 may therefore need servicing in order for the working machine 10 to be operable. This process can be time consuming and costly, and the working machine 10 is unable to operate during servicing. The working machine 10 includes an additive dosing system 50, illustrated in Figures 2 and 3. The additive dosing system 50 is configured to supply an additive to the engine system. In particular, the additive dosing system 50 is configured to supply additive to the fuel injectors 32 of the engine. The additive dosing system 50 is configured to automatically supply additive to the engine system 40. The additive may be a detergent, for example a surfactant, a volatile compound or a mixture thereof. Providing additive to the engine system 40 helps to remove fuel from the fuel injectors 32 so as to clean such components of the engine system 20 before servicing is required. Automatically supplying additive to the engine system 20 helps to prevent malfunction of components in the engine system 20, for example the fuel injectors 32, and reduces the likelihood of the engine system 20 needing servicing, which can be an expensive and timeconsuming process. In addition, the automation of supply of additive reduces the reliance on the operator to add additive to the engine system 20, and reduces the level of manual labour involved with maintenance of the engine system 20. The additive dosing system 50 includes an additive reservoir 52, an additive supply line 54 fluidly connecting the additive reservoir 52 to the fuel line 28a, 28b and a valve arrangement 64. The additive supply line 54 supplies additive to the fuel line 28a, 28b and / or to the fuel reservoir 26. As such, additive may be mixed with fuel supplied to the engine 24, fuel returned to the fuel reservoir 26, or fuel in the fuel reservoir 26. In particular, the additive dosing system 50 is configured to automatically supply a predetermined volume of additive to the fuel line 28a, 28b and / or to the fuel reservoir 26. It shall be appreciated that the additive supply line 54 may supply additive to the fuel line 28a, 28b and the fuel reservoir 26 in some embodiments, or to one of the fuel reservoir 26 or the fuel line 28a, 28b in other embodiments. In the embodiment shown in Figures, the additive supply line 54 supplies additive to the fuel line 28a, 28b. Accordingly, hereafter the teachings will be described in relation to the supply of additive to the fuel line 28a, 28b for reasons of conciseness and brevity. It shall be appreciated that the teachings described in relation to the Figures are applicable to embodiments where the additive supply line 54 supplies additive to the fuel reservoir 26. The additive reservoir 52 may have a storage capacity in the range 0.4L to 25L. In some embodiments, for example large working machines 10, the additive reservoir may have a storage capacity up to or exceeding 10L. It shall be appreciated that in alternative embodiments, the additive reservoir 52 may have any suitable storage capacity, for example depending on a storage capacity of the fuel tank 26. The additive dosing system 50 may supply additive to the fuel supply line 28a or the fuel return line 28b. In the embodiment shown in Figure 3, the additive dosing system 50 supplies additive to the fuel supply line 28a. The pump arrangement 30 of the engine system of the working machine 10 is configured to draw additive from the additive reservoir 52 and into the fuel line 28a, 28b of the engine system 20. As such, the additive dosing system 50 uses the pump arrangement 30 of the working machine 10 to circulate additive, thereby reducing the number of components and complexity of the additive dosing system 50 and providing a more compact additive dosing system 50. In the embodiment shown in Figure 3, the additive dosing system 50 is connected to the fuel supply line 28a upstream of the pump arrangement 30, for example upstream of the low-pressure pump 40. As such, additive is drawn out of the additive reservoir 52 by the low-pressure pump 40. It shall be appreciated that in alternative embodiments, the additive dosing system 50 may be located at any suitable location along the fuel supply line 28a, for example between the low-pressure pump 40 and the high-pressure pump 46. The additive dosing system 50 is illustrated in detail in Figure 3. In the embodiment of Figure 3, the additive reservoir 52 is located above the additive supply line 54, in use. In particular, the additive reservoir 52 is located above an outlet 56 of the additive supply line 54, in use, such that additive is supplied under gravity to the additive outlet 56 via the additive supply line 54. The additive supply line 54 is substantially linear. As illustrated schematically in Figure 2, the additive supply line 54 is arranged to extend substantially vertically, in use. As such, the additive outlet 56 is vertically aligned with respect to the additive reservoir 26, in use. It shall be appreciated that in alternative, embodiments, any suitable shape of additive supply line 54 may be used, for example depending on spatial constraints of the engine system 20 and the working machine 10. It shall be appreciated that in alternative embodiments, the additive dosing system 50 may include a dedicated additive pump fortransporting additive from the additive reservoir 52 to the fuel line 28a, 28b. In such embodiments, the additive reservoir 52 may not be located above the fuel supply line 54. As such, the additive dosing system 50 may not use a gravity in-feed to supply additive to the fuel line 54, and instead the additive pump may be used to circulate additive. This is particularly advantageous in embodiments where the fuel reservoir 52 and / or fuel line 28a, 28b is located high up on the working machine 10 with respect to a ground surface. The additive outlet 56 may be any suitable device used to fluidly connect the additive supply line 54 to the fuel line 28a, 28b or the fuel reservoir 26 in alternative embodiments. For example, the additive outlet 56 may be a hose connector 56, for example a T-shaped hose connector 56 as shown in Figure 3. The additive outlet 56 may be used to connect the additive dosing system 50 to the fuel supply line 54 such that the additive dosing system 50 can be retrofitted to existing working machine 10, or supplied as part of the engine system 40 of a new working machine 10. The additive reservoir 52 is located in a housing 58. The housing 58 may be any suitable shape for storing additive. The additive supply line 54 is mounted to a lowermost surface of the housing 58. The housing 58 includes an additive inlet 60. In the embodiment shown in Figure 3, the additive inlet 60 is located on an uppermost surface thereof, however in alternative embodiments the additive inlet 60 may be located at any suitable location on the housing 58. The additive inlet 60 is used to refill the additive reservoir 52 with additive. The additive inlet 60 includes a cap 62 removably mounted thereto. As such, the cap 62 can be removed from the additive inlet 60 and the operator can pour additive into the housing 58 via the additive inlet 60 to refill the additive reservoir 52 with additive. The valve arrangement 64 is on the additive supply line 54. The valve arrangement 64 is located between the additive reservoir 52 and the additive outlet 56. The valve arrangement 64 is configured to control the supply of additive to the fuel line 28a, 28b of the engine system 40. In particular, the valve arrangement 64 is moveable between an open position in which additive can flow therethrough and a closed position in which flow of additive to the fuel line 28a, 28b is prevented. In the embodiment shown in Figure 3, the valve arrangement 64 includes a solenoid valve configured to control the supply of additive to the fuel line 28a, 28b. In alternative embodiments, the valve arrangement 64 may include any suitable valve, for example a proportional valve or a fixed displacement pump. The additive supply line 54 is provided as a first section 54a and a second section 54b. The first section 54a and the second section 54b are connected by the valve arrangement 64. In use, the first section 54a is an upper section 54a and the second section 54b is a lower section 54b. The first and second sections 54a, 54b are substantially linear and extend vertically. As such, the valve arrangement 64 is vertically aligned with the additive reservoir 52 and the additive outlet 56. The additive dosing system 50 is connected to a control system 66 of the working machine 10. In particular, the additive dosing system 50 includes an electrical connection device 68, shown in Figure 3, configured to connect the additive dosing system 50 to the control system 66 of the working machine 10. As such, the complexity of the additive dosing system 50 is reduced. This also enables the additive dosing system 50 to be retrofitted to existing working machines 10. The control system 66 controls movement of the valve arrangement 64, for example of the solenoid valve, between the open position and the closed position. As such, the control system 66 of the working machine 10 controls the supply of additive from the additive dosing system 50 to the fuel line 28a, 28b. It shall be appreciated that in alternative embodiments, the additive dosing system 50 may include a separate controller to that of the working machine 10 for controlling the supply of additive from the additive dosing system 50 to the fuel line 28a, 28b. Figure 4 shows a block diagram of the components of the working machine 10 which are in communication with the control system 66 of the working machine 10. In the embodiment shown in Figure 4, the predetermined volume of additive is dependent on a volume of fuel in the fuel reservoir 26, or a fuel level of fuel in the fuel reservoir. As such, the control system 66 is configured to determine a fuel level of fuel in the fuel reservoir 26, and the predetermined volume of additive is based on the fuel level. In the embodiment shown in Figure 4, the engine system 40 includes a fuel level sensor 70 in communication with the control system 66 and configured to sense a level of fuel in the fuel tank 70. It shall be appreciated that alternative sensors may be used instead or in addition to the fuel level sensor 70 to sense the fuel level in the engine system 20. For example, the fuel level in the engine system 20 may be determined based on a difference between volume of fuel supplied to the engine 24 and volume of fuel returned to the fuel reservoir 26, or using any alternative method. By way of example, a ratio of the predetermined volume of additive to the fuel line 28a, 28b to the fuel level of fuel in the fuel reservoir 26, may be in the range 0.01:1 to 0.0001:1, optionally in the range 0.005:1 to 0.0005:1, for example approximately 0.001:1. By way example, for a 200 litre fuel tank 26, the predetermined amount may be 200ml when the fuel tank is full or nearly full. In some embodiments, the control system 66 may be configured to continuously, for example intermittently, determine the fuel level of fuel in the fuel reservoir 26. The predetermined volume may be proportional to the fuel level of fuel in the fuel reservoir 26. By way of example, if the controller 66 determines that the fuel level of fuel in the fuel reservoir 26 is 75% (i.e. the fuel reservoir 26 is 75% full), the predetermined volume of additive supplied to the fuel line 28a, 28b may be approximately 75% of the predetermined volume of additive supplied to the fuel line 28a, 28b for a full fuel tank 26 (i.e. when the fuel level is approximately 100%). In some embodiments, the dosing module 50 may supply additive to the engine system 20 when fuel is added to the fuel reservoir 26 (e.g. immediately or shortly after refuelling of the fuel tank 26). The control system 66 may determine that refuelling of the fuel tank 26 has occurred, and determine a volume of fuel which has been added to the fuel tank 26, for example using the fuel level sensor 70. The volume of additive supplied to the fuel line 28a, 28b is proportional to the increase in the fuel level of fuel tank 26 after refuelling has occurred. By way of example, if the fuel tank 26 is 50% full and during refuelling it is filled by 25%, the fuel tank 26 has a fuel level of 75%. The predetermined volume supplied to the fuel line 28a, 28b may therefore be approximately 75% of the predetermined volume for a full fuel tank 26. In some embodiments, the volume of additive supplied to the fuel line 28a, 28b may be proportional to the volume of fuel added to the fuel tank 26. Using the above example, if during refuelling the fuel tank 26 is filled by 25%, the predetermined volume supplied to the fuel line 28a, 28b may therefore be 25%. The control system 66 is configured to move the valve arrangement 64 into the open position for a predetermined time to supply the predetermined volume of additive to the fuel line 28a, 28b. As such, instead of measuring the predetermined volume, the control system 66 may determine the predetermined time based on a known flow rate of additive through the valve arrangement 64 to deliver the predetermined volume. To increase the predetermined volume, the valve arrangement 64 is held in the open position for a greater time period, and to decrease the predetermined volume, the valve arrangement 64 is held in the predetermined time for a smaller time period. As such, the control system 66 is configured to reduce the predetermined time the valve arrangement 64 is in the open position when the fuel level in the fuel reservoir 26 is below a predetermined fuel level threshold so as to reduce the volume of additive supplied to the fuel line 28a, 28b of the engine system 20. The predetermined fuel level threshold may be 70%, for example 60%, optionally 50%, optionally 15% or less. In some embodiments, as described above, the control system 66 may be configured to adjust the predetermined time period proportionally depending on the fuel level of fuel in the fuel reservoir 26 to supply the predetermined volume. For example, if the fuel level of fuel in the fuel reservoir 26 is 75%, the predetermined time period may be approximately 75% of the predetermined time period when the fuel level of fuel in the fuel reservoir is approximately 100%. The additive dosing system 50 may be configured to periodically supply additive from the additive reservoir to the fuel line 28a, 28b at predetermined time intervals. The predetermined time interval may be in the range 400 hours to 600 hours, optionally in the range 450 hours to 550 hours. The control system 66 determines the fuel level of fuel in the fuel reservoir 26, as described above, and the predetermined time interval is determined based on the determined fuel level of fuel in the fuel reservoir 26. The predetermined time interval may be adjusted by the control system 66 depending on the fuel level of fuel in the fuel tank 26. The control system 66 may be configured to reduce the predetermined time interval when it is determined that the fuel level of fuel in the fuel reservoir 26, is below the predetermined fuel level threshold. For example, the control system 66 may be configured to reduce the predetermined time interval at lower fuel levels such that additive is supplied more frequently at lower fuel levels. This is because at lower fuel levels, a greater proportion of the fuel left in the fuel reservoir 26 is being used as the engine 24 is run, meaning it is advantageous to increase the frequency of dosing so that the optimum concentration of additive is mixed in the fuel. In some embodiments, the control system 66 is configured to overdose the fuel with additive. In particular, the control system 66 may be configured to overdose the fuel with additive by a predetermined amount to achieve a predetermined concentration of additive in the fuel reservoir 26 when fuel is returned from the engine 24 to the fuel reservoir 26. Overdosing helps to ensure that there is sufficient additive remaining in the fuel mixture to clean the fuel injectors 32. The predetermined amount may be determined based on a difference between a volume of fuel supplied to the engine 24 and a volume of fuel returned to the fuel reservoir 26. For example, if 10% more fuel is supplied to the engine 24 than returned to fuel reservoir 26, then the predetermined volume may be increased by a predetermined amount of 10%. This means that the predetermined concentration of additive, which may be the optimal concentration for cleaning the fuel injectors 32, is in the fuel reservoir 26 for circulation by the pump arrangement This means that the amount of additive mixed in with the fuel is greater than required for a small period of time, but that as fuel is used by the engine 24, there is sufficient additive mixed in with the fuel to clean the fuel injectors 32. The additive dosing system 50 is configured to supply additive to the fuel line 28a, 28b when the engine 24 is in running, i.e. when the engine 24 is in an active state. This helps to ensure good mixing of additive with the fuel. The control system 66 is configured to determine the engine speed of the engine 24. The additive dosing system 50 is configured to automatically supply additive from the additive reservoir 26 to the fuel line 28a, 28b of the engine system 24 only when it is determined that the engine system is in an active state. The additive dosing system 50 may be configured to supply additive to the fuel lines 28a, 28b when an engine speed of the engine 24 is above a predetermined engine speed threshold. The predetermined engine speed threshold may, in some embodiments, be an engine idle speed threshold. The engine speed threshold may be greater than 700rpm, for example greater than 800rpm, optionally greater than 850rpm. In some embodiments, the engine speed threshold may be greater than lOOOrpm, for example greater than 1100 rpm, for example 1200 rpm. The engine system 20 includes an engine speed sensor 72 configured to measure an engine speed of the engine 24. The engine speed sensor 72 is in communication with the control system 66 such that the control system 66 is configured to active the additive dosing system 50 when the engine speed is above the predetermined engine speed threshold. The control system 66 may be configured to determine an additive level of additive in the additive reservoir 52. The additive level may be determined based on the maximum additive level of additive in the additive reservoir 52 and the number of times the predetermined volume has been supplied, or the additive dosing system 50 may include a sensor 74 configured to measure the additive level of additive in the additive reservoir 26. The additive level sensor 74 is in communication with the control system 66, such that the control system 66 can activate the additive dosing system 50 when it is determined that the additive level is above a predetermined additive threshold. The predetermined additive threshold may be 5%, for example 10%, optionally 20%, optionally 30%, optionally 40%. The control system 66 may be configured to produce an output 78 indicative of the additive level in the additive reservoir 26 when it is determined that the additive level of additive in the additive reservoir 26 is below the predetermined threshold. It shall be appreciated that in some embodiments, the predetermined threshold for producing the output 78 may differ from the predetermined threshold for activating the additive dosing system 50. By way of example, the predetermined additive threshold for producing the output 78 may be greater than the predetermined additive threshold for activating the additive dosing system 50. The output 78 may be an alert, for example a visual or audio alert. This alerts the user that they need to refill the additive reservoir 26 with additive, for example by removing the cap 62 and pouring additive into the additive inlet 60. Figure 5 illustrates an exemplary embodiment of the control logic for controlling the additive dosing system 50. It shall be appreciated that the control logic and values are exemplary, and that alternative method steps fall within the scope of the control logic used to control the additive dosing system 50. As described above, the control system 66 uses inputs from the fuel level sensor 70, engine speed sensor 72 and additive level sensor 74 to control the supply of additive from the additive reservoir 26 to the fuel line 28a, 28b. At step 100, the control system 66 sets the predetermined time interval to 500 hours. At step 102, if the control system 66 determines that it is the first time dosing, the valve arrangement 64 is moved into the open position for 10 seconds to deliver the predetermined volume of additive to the fuel supply line 28a, 28b, shown at step 103. By way of example, if the fuel tank is a 200 litre fuel tank, the predetermined volume may be 200ml. This is to prime the fuel with additive such that additive is supplied to the engine system 20 during operation of the engine 24. The control logic then moves on to step 104. If the control system 66 determines that it is not the first time dosing, the control logic moves to step 104. At step 104, the control system 66 determines whether the engine speed is greater than the predetermined engine speed threshold and whether the additive level is above the predetermined additive threshold. In the embodiment shown in Figure 5, the engine speed threshold is 850rpm and the additive threshold is 5%. As described above, the additive threshold may be any suitable value, for example 10%, 20%, 30%, 40%, greater or any threshold in between. If the engine speed is below the engine speed threshold and / or the additive level is below the predetermined threshold, then the additive dosing system is "OFF", as illustrated at step 105. Put another, way, the predetermined volume of additive is not supplied to the fuel line 28a, 28b. The control system 66 may issue the output 78 to indicate to the operator that the additive level is below the predetermined additive threshold so that the operator can refill the additive reservoir 26. If the control system 66 determines that the engine speed is greater than the engine speed threshold and the additive level is above the additive level threshold, then the control logic moves on to step 106. At step 106, the control system 66 determines whether the fuel level is above the predetermined fuel threshold based on the input from the fuel level sensor 72. In the embodiment shown in Figure 5, the predetermined fuel threshold is 50%. If the control system 66 determines that the fuel level is greater than the predetermined fuel threshold, the control system 66 moves the valve arrangement 64 into the open position for the predetermined time to deliver the predetermined volume of additive to the fuel line 28a, 28b, as illustrated at step 107. In the embodiment of Figure 5, the predetermined time is ten seconds. The valve arrangement 64 is opened periodically every 500 hours for the predetermined time until a predetermined total volume of additive has been supplied to the fuel line 28a, 28b. The predetermined total volume may be a volume of additive considered optimal or sufficient to maintain the condition of the fuel injectors 32. The predetermined total volume may be determined using pre-testing and / or component analysis. At step 108, increment counter A is started to count the number of doses. If the control system 66 determines that the fuel level is below the predetermined fuel threshold, as shown at step 109, the predetermined time is reduced so as to reduce the predetermined volume of additive supplied to the fuel line 28a, 28b. In the embodiment of Figure 5, the predetermined time is reduced to 5 seconds (i.e. halved) when it is determined that the fuel level is less than 50%. This halves the predetermined volume. At step 110, increment counter B is started to count the number of doses. At step 111, the control system 66 determines whether the counters A and / or B are greater than five (i.e. whether the predetermined volume has been supplied more than five times). It shall be appreciated that in alternative embodiments, the control system 66 may determine whether the counters A and / or B are greater than any suitable value, for example 1, 2, 3, 4, 6 or greater. If the counter is greater than five, the control system 66 determines whether the fuel level is greater than the predetermined fuel volume at step 112. If the counter is less than five, the control system 66 continues dosing according to steps 110 and 108. If the control system 66 determines that the fuel level is above the predetermined threshold of 50%, the predetermined time is reduced to 250 hours at step 114 and the predetermined time is increased to ten seconds. This is because there is a greater fuel level in the fuel reservoir 26, so the frequency at which additive is supplied is increased. The control system 66 continues to supply additive periodically every 250 hours for ten seconds. At step 115, increment counter C is started to count the number of doses. If the control system 66 determines that the fuel level is below the predetermined threshold of 50%, the predetermined time is decreased to 250 hours and the predetermined time remains at five seconds, as illustrated at step 116. The control system 66 continues to supply additive periodically every 250 hours for five seconds unit. At step 117, increment counter D is started to count the number of doses. The additive dosing system 50 may continue to supply additive for an arbitrary number of does. As illustrated in Figure 5, the control logic may determine at step 118 whether the counters C and / or D are greater than five (i.e. whether the predetermined volume has been supplied more than five times). It shall be appreciated that in alternative embodiments, the control system 66 may determine whether the counters C and / or D are greater than any suitable value, for example one, two, three, four, six, or greater. If the counter C or D is greater than five, the control logic ends. If the counter is less than five, the control logic returns to step 114 or 116. It shall be appreciated that in alternative embodiments, the counters A to D may be omitted. An alternative embodiment in which the control system 66 determines the predetermined volume and / or the predetermined time period based on the fuel level of fuel in the fuel reservoir 26 will be described hereafter. In such embodiments, the control system 66 may be configured to determine the fuel level at step 106 and to supply the predetermined volume of additive as a proportion of the fuel in the fuel reservoir. For example, if the controller determines the fuel level is 75%, then 75% of the predetermined volume supplied to the fuel line 28a, 28b when the fuel reservoir 26 is full may be supplied to the fuel line 28a, 28b. The control system 66 may continuously, for example intermittently, determine the fuel level of fuel in the fuel reservoir 26, and proportionally adjust the predetermined volume of additive depending on the fuel level. As described above, the control system 66 may determine when refuelling occurs, and supply additive 5 proportionally when a refuelling event occurs. It shall be appreciated that in alternative embodiments, the control system 66 may be omitted and the additive dosing system 50 may be controlled mechanically. Furthermore, the predetermined volume and / or predetermined time may be inputted by the operator. The one or more embodiments are described above by way of example only and it will be 10 appreciated that the various aspects and features may be variously modified. For example, although principally aimed towards material handling machines such as excavators, the disclosure may apply to other forms of working machine. These variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

1. A working machine comprising:a ground engaging propulsion structure;a body supported by the ground engaging propulsion structure;an engine system comprising:an engine configured to provide motive power to the ground engaging propulsion structure;a fuel reservoir;a fuel line fluidly connecting the fuel reservoir and the engine; andan additive dosing system comprising an additive reservoir, and an additive supply line fluidly connecting the additive reservoir to the fuel line and / or to the fuel reservoir for supplying additive to the fuel line and / or to the fuel reservoir, wherein the additive dosing system is configured to automatically supply a predetermined volume of additive to the fuel line and / or to the fuel reservoir.

2. The working machine according to claim 1, comprising a control system configured to determine a fuel level of fuel in the fuel reservoir, wherein the predetermined volume of additive is based on the fuel level.

3. The working machine according to claim 2, wherein the predetermined volume is proportional to the fuel level of fuel in the fuel reservoir.

4. The working machine according to claim 3, wherein the control system is configured to supply the predetermined volume of additive when it is determined that refuelling of the fuel reservoir has occurred, and wherein the predetermined volume is proportional to the increase in the immediately after refuelling has occurred.

5. The working machine according to claim 3 or claim 4, wherein a ratio of the predetermined volume of additive supplied to the fuel line and / or the fuel reservoir to the fuel level of fuel in the fuel reservoir is in the range 0.01:1 to 0.0001:1, optionally in the range 0.005:1 to 0.0005:1, for example approximately 0.001:1.

6. The working machine according to any preceding claim, comprising a control system configured to overdose the fuel with additive by a predetermined amount to achieve a predetermined concentration of additive in the fuel reservoir when fuel is returned from the engine to the fuel reservoir.

7. The working machine according to claim 6, wherein the predetermined amount is determined based on a difference between a volume of fuel supplied to the engine and a volume of fuel returned to the fuel reservoir.

8. The working machine according to any preceding claim, wherein the additive dosing system comprises a valve arrangement on the additive supply line, and wherein the valve arrangement is configured to control the supply of additive to the fuel line and / or to the fuel reservoir of the engine system.

9. The working machine according to claim 8, wherein the valve arrangement is moveable between an open position and a closed position, and wherein the valve arrangement is moved into the open position for a predetermined time to supply the predetermined volume of additive to the fuel line and / or to the fuel reservoir.10.The working machine according to claim 8 or claim 9, wherein the valve arrangement comprises a solenoid valve configured to control the supply of additive to the fuel line and / or to the fuel reservoir.11.The working machine according to any preceding claim, wherein the dosing module is configured to periodically supply additive from the additive reservoir to the fuel line and / or the fuel reservoir of the engine system at predetermined time intervals.

12. The working machine according to claim 11, comprising a control system configured to determine a fuel level of fuel in the fuel reservoir, wherein the predetermined time interval is based on the determined fuel level.

13. The working machine according to claim 11 or claim 12, wherein the predetermined time interval is in the range 400 hours to 600 hours, optionally in the range 450 hours to 550 hours.14.The working machine according to any preceding claim, comprising a control system configured to determine an additive level of additive in the additive reservoir, wherein the control system is configured to produce an alert when it is determined that the additive level is below a predetermined additive threshold.15.The working machine according to any preceding claim, comprising a control system configured to determine an additive level of additive in the additive reservoir, wherein the additive dosing system is configured to automatically supplythe predetermined volume only when it is determined that the additive level is above a predetermined additive threshold.16.The working machine according to any preceding claim, comprising a control system configured to determine the engine speed of the engine, wherein the additive dosing system is configured to automatically supply additive from the additive reservoir to the fuel line and / or to the fuel reservoir of the engine system only when it is determined that the engine system is in an active state, optionally when an engine speed of the engine is above a predetermined engine speed threshold.17.The working machine according to any preceding claim, wherein the additive reservoir is located above the additive outlet of the additive supply line, in use, such that additive is supplied under gravity to the additive outlet via the additive supply line.18.The working machine according to any preceding claim, wherein the fuel line comprises a fuel supply line configured to supply fuel from the fuel reservoir to the engine and a fuel return line configured to return fuel from the engine to the fuel reservoir, and wherein the additive supply line is connected to the fuel supply line.

19. The working machine according to any preceding claim, wherein the additive supply line is connected to the fuel reservoir.

20. The working machine according to any preceding claim, wherein the engine system comprises a pump configured to transport fuel between the fuel reservoir and the engine, and wherein the additive supply line is connected to the fuel supply line upstream of the pump.21.The working machine according to any one of claim 1 to claim 19, wherein the additive dosing system comprises an additive pump configured to transport additive from the additive reservoir to the fuel supply line or fuel reservoir.22.The working machine according to any preceding claim, wherein the additive reservoir is located in a housing comprising an additive inlet, and wherein the additive inlet comprises a cap removably mounted thereto.23.The working machine according to any preceding claim, wherein the additive is a detergent, optionally wherein the additive is a surfactant, a volatile component or a mixture thereof.

24. An additive dosing system for a working machine, the system comprising:an additive reservoir;an additive supply line configured to connect the additive reservoir to a fuel line and / or to a fuel reservoir of the working machine for supplying additive to the fuel line and / or to the fuel reservoir; anda valve arrangement on the additive supply line and moveable between an open position and a closed position,wherein the valve arrangement is configured to be moved into the open position for a predetermined time to supply a predetermined volume of additive through the additive supply line.Application No: GB2414463.6Examiner: Dr Joe MahoneyClaims searched: 1-24Date of search: 12 February 2025Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1-24 US2006 / 0254535 Al (VALENTINE &KNAPPER) - Please see figures 1 and 3, paragraphs [0002], [0012], [0022], [0028], [0033], X 1-24 US6068672 A (WATSON &EGLE) - Please see figures 1,2 and 10, abstract and column 2 lines 53-67, column 4 lines 1-9. X 1-24 FR2668203 Al (PEUGEOT) - Please see figure and abstract. X 1-24 US5331994 A (BRYAN III et.al) - Please see figures 1 and 2, the abstract and column 4 lines 19-53. X 1-24 WO2009 / 035339 Al (KRONBORG) - Please see figure, abstract and description, taking note of additive reservoir 2, additive dosing means 4.Categories:X Document indicating lack of novelty or inventive step A Document indicating technological background and / or state of the art. Y Document indicating lack of inventive step if P Document published on or after the declared priority date but combined with one or more other documents of same category. before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:Search of GB, EP. WO &US patent documents classified in the following areas of the UKCX :International Classification:Subclass Subgroup Valid From F02D 0019 / 12 01 / 01 / 2006 F02D 0041 / 00 01 / 01 / 2006 F02M 0025 / 14 01 / 01 / 200627

Images