Work machine

The work machine's identification sensor and control system ensure engines using multiple carbon-neutral fuels avoid failure by accurately identifying fuel types and ratios, enabling operators to prevent inappropriate fuel usage and maintain engine operation.

WO2026140476A1PCT designated stage Publication Date: 2026-07-02KUBOTA CORP

Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
KUBOTA CORP
Filing Date
2025-10-28
Publication Date
2026-07-02

AI Technical Summary

Technical Problem

Engines that can operate on multiple types of carbon-neutral fuels are prone to failure when inappropriate fuels are used, and existing systems lack effective methods to prevent such occurrences.

Method used

A work machine equipped with an identification sensor that determines the type and mixing ratio of carbon-neutral fuels, coupled with a display and control system to prevent engine operation with inappropriate fuels, and issue warnings when necessary.

Benefits of technology

Prevents engine failure by accurately identifying suitable fuels, allowing operators to take corrective actions, thereby ensuring the engine operates with appropriate fuels and maintaining efficiency.

✦ Generated by Eureka AI based on patent content.

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Abstract

This work machine comprises: an engine 6 which is capable of being driven by each of a plurality of types of fuels including a carbon neutral fuel; an identification sensor 10 which identifies the type of a carbon neutral fuel and outputs identification information; and a display device which obtains and displays the identification information output by the identification sensor 10.
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Description

Work machine

[0001] The present invention relates to a work machine equipped with an engine driven by a carbon-neutral fuel.

[0002] There is a work machine equipped with an engine that can be driven by multiple types of carbon-neutral fuels, and furthermore, a mixed fuel of multiple different carbon-neutral fuels. Such an engine can be driven by at least either a predetermined carbon-neutral fuel or a carbon-neutral fuel with a predetermined mixing ratio.

[0003] In such an engine, if an inappropriate fuel other than the drivable fuel is used, engine problems such as engine failure may occur.

[0004] In order to use an appropriate fuel, in the construction machine described in Patent Document 1, a sensor for detecting the physical quantity of the fuel is provided.

[0005] Japanese Patent Application Laid-Open No. 2011-94549

[0006] An object of the present invention is to suppress the driving of an engine with an inappropriate fuel based on the identification result of a sensor.

[0007] To achieve the above object, a work machine according to an embodiment of the present invention includes an engine that can be driven by each of a plurality of types of fuels including a carbon-neutral fuel, an identification sensor that identifies the type of the carbon-neutral fuel and outputs identification information, and a display device that acquires and displays the identification information output by the identification sensor.

[0008] There may be a case where an inappropriate fuel for driving the engine is accidentally used. Driving the engine with an inappropriate fuel may cause engine failure. According to the above configuration, since the identification result of the fuel is displayed on the display device, the operator can check the display device to confirm whether an appropriate fuel is being used, and if an inappropriate fuel is being used, it is possible to take measures such as stopping the engine. As a result, it is possible to suppress the driving of the engine with an inappropriate fuel.

[0009] Furthermore, the identification sensor may include a measuring unit that acquires predetermined information relating to the fuel, and a calculation unit that performs calculations to identify the fuel based on the information and outputs the identification information.

[0010] Since the identification sensor is divided into a measurement unit and a calculation unit, as long as the measurement unit is placed in a position where it can come into contact with the fuel, the calculation unit can be placed in any position. This allows for a high degree of flexibility in positioning the identification sensor while also enabling efficient placement.

[0011] Furthermore, if the fuel is a mixture of multiple carbon-neutral fuels, the identification information may include at least one of the types of carbon-neutral fuels to be mixed, the mixing ratio of the carbon-neutral fuels, and the carbon dioxide reduction effect.

[0012] Some engines can be powered by a predetermined mixture of carbon-neutral fuels. Identification sensors can detect the type and mixing ratio of carbon-neutral fuels, making it possible to determine whether the fuel being used is suitable for powering the engine. Furthermore, the identification sensors can detect the carbon dioxide reduction effect, allowing for work to be carried out while confirming the contribution of the fuel being used to environmental conservation.

[0013] The system may also include a warning unit that issues a predetermined warning, a determination unit that determines whether or not the warning is necessary based on the identification information, and a warning control unit that causes the warning unit to issue the warning based on the determination of the determination unit.

[0014] This configuration allows the system to issue a warning when a specific fuel is being used, enabling workers to recognize that the specific fuel is being used and take appropriate action. The specific fuel is, for example, when an unsuitable fuel for driving the engine is being used.

[0015] Furthermore, if the fuel is a mixture of multiple carbon-neutral fuels, the identification information is the mixing ratio of the carbon-neutral fuels, and the determination unit may determine that the warning is necessary if the mixing ratio is outside a predetermined range.

[0016] The engine may be able to run on multiple types of carbon-neutral fuels in predetermined mixing ratios. According to the above configuration, the system determines whether the mixing ratio of the carbon-neutral fuels being used is appropriate for driving the engine, and a warning is issued if it is deemed inappropriate. As a result, the operator can recognize that an inappropriate fuel is being used and take appropriate action.

[0017] The system further includes a control unit that controls the operation of the engine, and the control unit may stop the engine when the identification information is in a predetermined state.

[0018] This configuration allows the engine to be automatically shut off if unsuitable fuel is used to power it, thus preventing engine failure or other undesirable conditions caused by the use of inappropriate fuel.

[0019] This is a diagram illustrating the overall configuration of a rice transplanter, which is a work machine. This is a diagram illustrating the overall configuration of a tractor, which is a work machine. This is a diagram illustrating the overall configuration of a backhoe, which is a work machine. This is a diagram illustrating the relationship between the fuel supply path to the engine and the identification sensor. This is a diagram illustrating the operation flow of the identification sensor. This is a cross-sectional view illustrating the configuration of an identification sensor installed in a sub-tank. This is a diagram illustrating the positional relationship between the fuel inlet and fuel outlet in the sub-tank. This is a diagram illustrating the positional relationship between the fuel inlet and fuel outlet in the sub-tank. This is a diagram illustrating an example of a configuration in which the fuel filter, sub-tank, and identification sensor are integrated. This is a schematic diagram showing a cross-section of a part of the fuel flow configuration in an example of a configuration in which the fuel filter, sub-tank, and identification sensor are integrated. This is a diagram illustrating the arrangement relationship between the fuel flow path and the fuel filter. This is a diagram illustrating the arrangement relationship between the fuel flow path and the fuel filter. This is a diagram illustrating the arrangement relationship between the fuel flow path and the fuel filter.

[0020] [Agricultural Machinery] As shown in Figure 1, agricultural machinery such as rice transplanters 2, tractors 3, and backhoes 4, which perform specific tasks including farm work, are equipped with working devices for their respective tasks. The working devices are operated by power supplied from a power source such as an engine 6. Therefore, each agricultural machine is equipped with an engine 6 that outputs power and a fuel tank 8 that stores the fuel supplied to the engine 6.

[0021] Some engines 6 operate only on specific fuels such as gasoline or diesel. On the other hand, some engines 6 can use multiple types of fuel. For example, an engine 6 can be powered by several types of fuel, including carbon-neutral fuels. Such engines 6 can operate on biofuels, synthetic fuels, and can use several specific types of fuel, including carbon-neutral fuels. Some can also use fuels that are mixtures of such fuels in predetermined proportions (mixing ratios).

[0022] In other words, such an engine 6 can use a specific set of fuels, but cannot use any other fuels. If an unsuitable fuel is supplied to the engine 6, problems such as engine failure will occur. Therefore, it is preferable that a work machine equipped with such an engine 6 be provided with an identification sensor 10 (see Figure 4) that identifies the fuel supplied to the engine 6.

[0023] Engine 6 can use various fuels, including diesel fuel, biofuels such as HVO (Hydrotreated Vegetable Oil) and biodiesel fuel, synthetic fuels, and mixtures thereof.

[0024] [Placement of Identification Sensor] As shown in Figure 4, the fuel stored in the fuel tank 8 flows through the fuel flow pipe 12 connected to the fuel tank 8 and the engine 6. In other words, the fuel flow pipe 12 is connected to the fuel tank 8 and the engine 6, and fuel flows through it. Specifically, the engine 6 is equipped with an engine supply pump 6A, and the fuel flow pipe 12 is connected across the fuel tank 8 and the engine supply pump 6A. The engine supply pump 6A draws fuel stored in the fuel tank 8 and delivers it to the engine 6 via the fuel flow pipe 12.

[0025] The fuel supply pipe 12 includes a supply pipe 13 and a return pipe 14. The supply pipe 13 is the path for supplying fuel from the fuel tank 8 to the engine 6 (engine supply pump 6A). The return pipe 14 is the path for returning fuel from the engine 6 to the fuel tank 8. The supply pipe 13 is equipped with a fuel filter 18 that removes foreign matter from the fuel supplied to the engine 6. In addition to the supply pipe 13 and the return pipe 14, the fuel supply pipe 12 also includes a branch pipe 15 that allows fuel to flow from the fuel filter 18 to the return pipe 14. At least a portion of the fuel from which foreign matter has been removed by the fuel filter 18 is supplied from the fuel filter 18 to the engine 6 (engine supply pump 6A) via the supply pipe 13. The remaining fuel is returned from the fuel filter 18 to the fuel tank 8 via the branch pipe 15 and the return pipe 14.

[0026] The identification sensor 10 identifies at least one of the following: the type of fuel supplied to the engine 6 and its mixing ratio. The type of fuel is whether it is diesel fuel, biofuel such as HVO or biodiesel fuel, or synthetic fuel, or it is a specific type of fuel. In other words, the identification sensor 10 identifies whether the fuel is a carbon-neutral fuel or a fuel other than a carbon-neutral fuel such as diesel fuel, and may also identify which type of carbon-neutral fuel it is. Furthermore, if the fuel is a mixture of carbon-neutral fuels (blended fuel), the identification sensor 10 identifies the mixing ratio of the carbon-neutral fuels along with the type of carbon-neutral fuel. Note that carbon-neutral fuels include synthetic fuels, e-fuel, biofuel, and hydrogen, and the identification sensor 10 may identify which of these the fuel is. Here, e-fuel is a fuel produced using hydrogen derived from renewable energy.

[0027] As shown in Figures 5 and 6, the identification sensor 10 includes a measurement unit 24 that acquires (measures and detects) predetermined measurement information 51 related to fuel, and a calculation unit 25 that performs calculations to identify the fuel based on the measurement information 51. In other words, the calculation unit 25 identifies the fuel by performing predetermined calculations based on the measurement information 51 acquired by the measurement unit 24. The calculation unit 25 then outputs identification information 52 as the calculation result (the result of identification).

[0028] As shown in Figure 4, the identification sensor 10 is directly installed in the fuel flow pipe 12. Specifically, the identification sensor 10 is installed in the supply pipe 13, and more specifically, the identification sensor 10 is installed between the fuel tank 8 and the fuel filter 18 in the supply pipe 13. As a result, identification processing is performed on the fuel supplied to the engine 6, enabling accurate identification of the fuel.

[0029] Furthermore, if the identification sensor 10 installed in the supply pipe 13 is damaged, fragments of the identification sensor 10 may enter the engine 6, potentially causing malfunctions such as failure or damage to the engine 6. Therefore, by installing the identification sensor 10 between the fuel tank 8 and the fuel filter 18 in the supply pipe 13 (upstream of the fuel filter 18), even if the identification sensor 10 is damaged, fragments will be caught by the fuel filter 18 (or any other device described later) and prevented from being supplied to the engine 6.

[0030] Furthermore, the fuel returned from engine 6 is heated in engine 6, or tiny bubbles are generated, which may prevent the identification sensor 10 from accurately identifying the fuel. Therefore, by installing the identification sensor 10 in the supply pipe 13, particularly between the fuel tank 8 and the fuel filter 18 in the supply pipe 13, rather than in the return pipe 14, the fuel can be identified with greater accuracy.

[0031] Furthermore, the identification sensor 10 may be provided in the return pipe 14, or it may be provided in the return pipe 14 between the engine 6 and the branch pipe 15 (position 21). With this configuration, when fuel temperature and minute bubbles are not a problem, the degree of freedom in the placement of the identification sensor 10 is increased.

[0032] While both the measuring unit 24 and the calculation unit 25 of the identification sensor 10 may be provided in the fuel flow pipe 12, at least the measuring unit 24 of the identification sensor 10 may be provided in the fuel flow pipe 12, and the calculation unit 25 may be provided at a location different from the fuel flow pipe 12. This allows the measuring unit 24, which needs to be in contact with the fuel, to be provided in the fuel flow pipe 12, and the calculation unit 25 to be provided in the fuel flow pipe 12 or at any other location, thereby enabling accurate fuel identification while efficiently positioning the identification sensor 10.

[0033] [Displaying Identification Results] Next, we will explain the configuration for displaying identification results using Figures 1 to 5.

[0034] The identification sensor 10 outputs the identification result as identification information 52. Specifically, the calculation unit 25 of the identification sensor 10 outputs the identification information 52. Preferably, the work machine is equipped with a display device that acquires and displays the identification information 52 output by the identification sensor 10. The display device may be independently provided on the work machine, but the identification information 52 may also be displayed on the display unit of an information terminal 27 provided on the work machine. The information terminal 27 is detachably mounted on the machine and is a terminal that allows the operator to perform various settings and operations, and to display various information to the operator.

[0035] As described above, the engine 6 according to this embodiment can use multiple types of fuel. That is, there are fuels that can be used in the engine 6 and fuels that cannot be used in the engine 6, and the identification sensor 10 can identify which type of fuel is being supplied to the engine 6. The identification result is displayed on the display unit, allowing the operator to determine whether the appropriate fuel is being used, and if an inappropriate fuel is being used, they can take measures such as stopping the engine 6. As a result, it is possible to prevent the engine 6 from being driven with an inappropriate fuel.

[0036] In this case, the work machine may further include a control unit 29 that controls the operation of the engine 6. The control unit 29 stops the engine 6 when the identification information 52 is in a predetermined state. For example, if the identification information 52 indicates that an inappropriate fuel is being used, the control unit 29 stops the engine 6. Note that while the engine 6 can still be used with some fuels, their use is not recommended. For example, such fuels may put a load on the engine 6. If the identification result indicates such a fuel, the control unit 29 may, instead of stopping the engine 6, limit the output of the engine 6 or issue a predetermined warning. This allows the work machine to use as many types of fuel as possible while suppressing the load on the engine 6.

[0037] If the fuel is a mixture of multiple carbon-neutral fuels, the identification information 52 preferably includes at least one of the types of carbon-neutral fuels to be mixed, the mixing ratio of the carbon-neutral fuels, and the carbon dioxide reduction effect.

[0038] As a result, even in an engine 6 that can use a mixture of multiple carbon-neutral fuels as fuel, the types of carbon-neutral fuels to be mixed and the mixing ratio of the carbon-neutral fuels are displayed, making it possible to determine whether or not the fuel is usable in the engine 6. As a result, it is possible to prevent the engine 6 from being driven with an inappropriate fuel. In the case of a single carbon-neutral fuel, the identification information 52 may be configured to include either the type of carbon-neutral fuel or the carbon dioxide reduction effect.

[0039] Furthermore, carbon-neutral fuels generally produce less carbon dioxide emissions than diesel fuel. The degree of reduction in carbon dioxide emissions (reduction effect) varies depending on the type of carbon-neutral fuel. The carbon dioxide reduction effect is one of the reasons for using carbon-neutral fuels. By displaying the carbon dioxide reduction effect, consumers can confirm the significance of using carbon-neutral fuels and easily select fuels with a higher carbon dioxide reduction effect.

[0040] [Warning] Along with the above display, or instead of displaying the above, a predetermined warning may be issued depending on the identification result. The following describes a configuration in which a predetermined warning is issued depending on the identification result, using Figures 1 to 5.

[0041] The work machine may issue a predetermined warning according to the identification result identified by the identification sensor 10. For this purpose, the work machine may further be equipped with a lamp 31 and a speaker 32 as warning units that issue predetermined warnings. Alternatively, an information terminal 27 or display device may also act as a warning unit to issue a warning. The work machine further includes a determination unit 34 that determines whether a warning is necessary according to the identification information 52, and a warning control unit 35 that causes the warning unit to issue a warning according to the determination unit 34's determination. When the determination unit 34 determines that a warning is necessary, the warning control unit 35 causes at least one of the information terminal 27, lamp 31, and speaker 32 to issue a warning. This allows the operator to determine whether the appropriate fuel is being used and to take measures such as stopping the engine 6 if inappropriate fuel is being used. As a result, it is possible to suppress the operation of the engine 6 with inappropriate fuel.

[0042] When a warning is issued using the information terminal 27 or display device, the display unit of the information terminal 27 displays images such as animations corresponding to the warning, or text data such as warning messages. When a warning is issued using the lamp 31, the warning is issued by flashing or lighting the lamp 31. The flashing, lighting, and patterns of these can give meaning to the warning. For example, a flashing lamp 31 can be a warning that unusable fuel is being supplied, and a lit lamp 31 can be a warning that mixed fuel is being supplied. When a warning is issued using the speaker 32, a warning sound or voice message indicating the warning is output from the speaker 32.

[0043] With such a configuration, the identification result can be conveyed to the operator in detail. For example, not only whether the fuel can be used in the engine 6, but also what type of carbon-neutral fuel is being supplied, whether it is a mixed fuel, and if so, what carbon-neutral fuel is being used, and further the mixing ratio, etc. are notified. Also, the carbon dioxide reduction effect may be notified. Further, when it is a mixed fuel, the determination unit 34 determines that a warning is necessary when the mixing ratio is outside a predetermined range that can be used in the engine 6, and the warning control unit 35 issues a predetermined warning when the determination unit 34 determines that a warning is necessary. With the above configuration, more detailed information about the supplied fuel is provided, and the driving of the engine 6 with inappropriate fuel can be suppressed more accurately.

[0044] [Alternative Embodiment] (1) In the above embodiment, as shown in FIGS. 4 to 6, the working machine may include a sub-tank 38 in the fuel flow pipe 12, and the identification sensor 10 may be connected to the sub-tank 38. For example, the sub-tank 38 to which the identification sensor 10 is connected may be arranged at an arbitrary position in the fuel flow pipe 12, but as described above, it is preferably arranged in the supply pipe 13, and more preferably arranged between the fuel tank 8 and the fuel filter 18 of the supply pipe 13. That is, the fuel filter 18 (equipment described later) is preferably arranged between the sub-tank 38 (identification sensor 10) and the engine 6.

[0045] The sub-tank 38 has a main body through which fuel passes, a fuel inlet 41 provided in the main body for fuel to flow in, and a fuel outlet 42 provided in the main body for discharging fuel in a direction different from the fuel inlet 41.

[0046] For example, the sub-tank 38 includes an identification space 39, a fuel inlet 41, and a fuel outlet 42 in the main body. The identification space 39 is a space provided inside the sub-tank 38 and is an area through which fuel passes. The fuel inlet 41 is an inlet through which fuel flows into the main body (identification space 39), and is connected to the fuel circulation pipe 12 to allow the fuel flowing through the fuel circulation pipe 12 to flow into the identification space 39 of the sub-tank 38. The fuel outlet 42 is an outlet for discharging fuel from the main body (identification space 39), and is connected to the fuel circulation pipe 12 to discharge the fuel that has flowed into the identification space 39 into the fuel circulation pipe 12.

[0047] The identification sensor 10 is inserted into the sub-tank 38 such that at least the measurement unit 24 is located inside the identification space 39 (main body) of the sub-tank 38. At this time, the calculation unit 25 of the identification sensor 10 may be exposed (arranged) outside the sub-tank 38, or may be located inside the sub-tank 38, and the calculation unit 25 may be arranged at any position of the work machine. For example, the calculation unit 25 may be provided on a side surface of the main body (identification space 39) where the fuel inlet 41 and the fuel outlet 42 are not provided.

[0048] In this way, the sub-tank 38 having the identification space 39 is provided in the fuel circulation pipe 12, and the identification sensor 10 is provided in the sub-tank 38 in such a manner that the measurement unit 24 is inserted into the identification space 39 (main body). The fuel flowing through the fuel circulation pipe 12 is temporarily stored in the identification space 39 (main body) of the sub-tank 38, and the flow rate decreases. Therefore, the identification sensor 10 with the measurement unit 24 inserted into the identification space 39 can sufficiently contact the fuel and accurately identify the fuel. As a result, the fuel can be accurately identified.

[0049] Here, it is preferable that the fuel outlet 42 discharges fuel in a direction different from that of the fuel inlet 41. For example, it is preferable that the fuel outlet 42 discharges fuel from the sub-tank 38 (identification space 39) upward in the direction of gravity G. This allows the fuel to flow against gravity, making it easy to reduce the fuel flow velocity within the identification space 39 (main body). It is also preferable that the fuel inlet 41 allows fuel to flow into the sub-tank 38 (identification space 39) from a direction different from that of the fuel outlet 42. This makes it even easier to reduce the fuel flow velocity within the identification space 39 (main body).

[0050] In particular, as shown in Figure 6, it is preferable that the fuel inlet 41 is located below the sub-tank 38 in the direction of gravity G, with respect to the fuel outlet 42, across the sub-tank 38. This allows fuel to flow from bottom to top against gravity within the sub-tank 38, temporarily stored in the identification space 39 along the way, and the fuel overflowing from the identification space 39 flows towards the fuel outlet 42. As a result, the measuring unit 24 can come into contact with the fuel that has almost stopped or whose flow velocity has been sufficiently reduced within the identification space 39, allowing for fuel identification (measurement of measurement information 51 (see Figure 5)). Consequently, fuel can be identified with high accuracy.

[0051] Furthermore, as shown in Figure 7, the fuel inlet 41 may be positioned so as to intersect with the direction of gravity G and the direction in which the identification sensor 10 is inserted. In other words, the fuel inlet 41 is positioned so as to intersect with the direction of fuel flow at the fuel outlet 42 (direction of gravity G) and the direction in which the identification sensor 10 is inserted. More specifically, if the surface on which the identification sensor 10 is installed is the lateral side surface and the surface on which the fuel outlet 42 is installed is the circumferential surface, the fuel inlet 41 is installed on the circumferential surface, not at the location where the fuel outlet 42 is installed, nor on the back surface of the location where the fuel outlet 42 is installed. Even with such a configuration, the measuring unit 24 can come into contact with the fuel whose flow velocity has been sufficiently reduced in the identification space 39, and perform fuel identification (measurement of measurement information 51 (see Figure 5)). As a result, the fuel can be identified with high accuracy.

[0052] Furthermore, as shown in Figure 8, the fuel inlet 41 may be located on the sub-tank 38, facing the identification sensor 10 across the sub-tank 38. In other words, the fuel inlet 41 is located on the back surface of the sub-tank 38 relative to the identification sensor 10, that is, in a position facing the identification sensor 10 on the sub-tank 38. Even with this configuration, the measuring unit 24 can come into contact with the fuel, whose flow velocity has been sufficiently reduced within the identification space 39, and perform fuel identification (measurement of measurement information 51 (see Figure 5)). As a result, the fuel can be identified with high accuracy.

[0053] Furthermore, as shown in Figures 6 to 8, it is preferable that the position where fuel flows in from the fuel inlet 41 to the sub-tank 38 is lower than the position where fuel is discharged from the fuel outlet 42. This allows the fuel to flow from bottom to top against gravity within the sub-tank 38, temporarily storing in the identification space 39 along the way, and the fuel overflowing from the identification space 39 flows towards the fuel outlet 42. As a result, the measuring unit 24 can come into contact with the fuel that has almost stopped or whose flow velocity has been sufficiently reduced within the identification space 39, allowing for fuel identification (measurement of measurement information 51 (see Figure 5)). Consequently, the fuel can be identified with high accuracy.

[0054] Furthermore, as shown in Figures 6 to 8, the identification sensor 10 may be provided on the side surface of the sub-tank 38 when the gravity direction G of the sub-tank 38 is defined as the vertical direction, with the measuring unit 24 inserted into the identification space 39. In other words, the identification sensor 10 is inserted into the sub-tank 38 from a direction intersecting the direction in which the fuel flows (gravity direction G) through the identification space 39. As a result, the measuring unit 24 extends in a direction intersecting the direction in which the fuel flows, allowing the identification sensor 10 to accurately identify the fuel (measurement of measurement information 51 (see Figure 5)).

[0055] (2) In the above alternative embodiment (1), as shown in Figure 9, the fuel filter 18 (device described later) is provided in the sub-tank 38. In other words, the identification sensor 10, the sub-tank 38, and the fuel filter 18 are provided integrally. With this configuration, the identification sensor 10, the sub-tank 38, and the fuel filter 18 can be efficiently arranged while accurately identifying the fuel.

[0056] The fuel filter 18 is connected to the fuel outlet 45. The sub-tank 38, to which the identification sensor 10 and fuel filter 18 are connected, has a fuel inlet 46 and a fuel return port 47. The fuel outlet 45 is connected to a fuel flow pipe 12 (supply pipe 13) that discharges fuel toward the engine 6. The fuel inlet 46 is connected to a fuel flow pipe 12 (supply pipe 13) that allows fuel to flow from the fuel tank 8 into the sub-tank 38. The fuel return port 47 is connected to a fuel flow pipe 12 (branch pipe 15) that allows fuel to flow from the sub-tank 38 back to the fuel tank 8.

[0057] In other words, fuel from the fuel outlet 45 toward the engine 6 flows through the supply pipe 13, and fuel from the fuel return port 47 of the sub-tank 38 toward the fuel tank 8 flows through the branch pipe 15 and then the return pipe 14. This configuration allows for efficient fuel distribution.

[0058] The identification sensor 10 is preferably provided on a side surface of the sub-tank 38 that intersects with the direction of gravity G (see Figure 6), similar to the other embodiment (1) (see Figures 6 to 9). For example, the sub-tank 38 and the fuel filter 18 can be connected side by side in the vertical direction (direction of gravity G), and the identification sensor 10 can be connected to the side of the sub-tank 38.

[0059] As shown in Figure 10, the fuel flowing in from the fuel inlet 46 flows into the inlet space 49 of the sub-tank 38, a portion of which reaches the identification space 39, and the remainder flows into the fuel filter 18 and is stored there. After the fuel that has flowed into the sub-tank 38 is identified by the identification sensor 10, it is discharged from the fuel return port 47 and returns to the fuel tank 8 via the branch pipe 15 and the return pipe 14. The fuel stored in the fuel filter 18 has foreign matter removed and is discharged from the fuel outlet 45 and supplied to the engine 6 via the supply pipe 13.

[0060] With this configuration, the fuel flowing in from the fuel inlet 46 is distributed to the identification sensor 10 and the fuel filter 18. Most of the fuel used for identification by the identification sensor 10 in the sub-tank 38 is returned to the fuel tank 8 via the fuel return port 47, and any fuel that is headed for the engine 6 flows to the engine 6 via the fuel filter 18. Therefore, only fuel from which foreign matter has been removed by the fuel filter 18 is supplied to the engine 6. Even if the identification sensor 10 is damaged, its fragments are removed from the fuel by the fuel filter 18, preventing them from reaching the engine 6. As a result, fuel can be identified accurately while suppressing malfunctions in the engine 6.

[0061] The fuel outlet 45 and fuel return port 47 may open in any direction, but it is preferable that they open upward (in the direction of gravity G). This allows the fuel to be discharged against gravity, making it easier to control the flow rate and enabling precise adjustment of the amount of fuel supplied to the engine 6 and the amount of fuel supplied to the identification space 39. As a result, the operation of the engine 6 can be controlled with precision, and the fuel can be identified with precision.

[0062] Furthermore, the identification sensor 10 and the fuel inlet 46 may be placed at any position on the sub-tank 38, or they may be provided on the side of the sub-tank 38. The direction of fuel inflow at the fuel inlet 46 may be in a direction that intersects with the direction in which the measuring unit 24 of the identification sensor 10 is inserted into the sub-tank 38, or it may be in a parallel direction. In other words, the positional relationship between the identification sensor 10 and the fuel inlet 46 on the side of the sub-tank 38 may be any positional relationship. Also, fuel may flow through the fuel inlet 46 from a direction that intersects with the direction in which fuel flows through the fuel outlet 45 and the fuel inlet 46 (gravity direction G), or it may flow from the same direction.

[0063] (3) In the above alternative embodiment (2), the sub-tank 38 may not be provided. In this case, the identification sensor 10 and the fuel filter 18 can be provided at any position.

[0064] For example, as shown in Figure 11, instead of the sub-tank 38, a base unit 55 is provided, which includes a fuel inlet 46 into which fuel flows and a fuel outlet 45 for discharging fuel. The base unit 55 has a mounting portion 56 to which a fuel filter 18 (a device described later) is attached. In other words, the fuel filter 18 is installed on the base unit 55 via the mounting portion 56.

[0065] The base portion 55 is a component that forms a flow path through which fuel flows in from the fuel inlet 46 and is discharged from the fuel outlet 45. The base portion 55 may also include a fuel filter 18. The identification sensor 10 can be provided on the base portion 55. The fuel flowing through the base portion 55 flows to the fuel filter 18 via the mounting portion 56.

[0066] This configuration allows for the efficient placement of the fuel filter 18 and the identification sensor 10. Furthermore, the fuel filter 18 (device) can be easily attached to the base unit 55. Because the fuel filter 18 is located in the base unit 55 through which fuel flows, the fuel filter 18 can accurately remove foreign matter from the fuel.

[0067] Furthermore, as shown in Figure 12, the base portion 55 may also include a fuel passage portion 58 and a storage portion 59. The fuel passage portion 58 is a member in which a fuel inlet 46 and a fuel outlet 45 are formed, and a flow path is formed through which fuel flows in from the fuel inlet 46 and is discharged from the fuel outlet 45. The storage portion 59 is an optional member provided in the fuel passage portion 58 for storing fuel. The mounting portion 56 for attaching the fuel filter 18 to the base portion 55 may also be provided in the fuel passage portion 58. In other words, the fuel filter 18 is provided in the base portion 55 via the mounting portion 56 of the fuel passage portion 58. The positional relationship between the storage portion 59 and the fuel filter 18 is arbitrary. Moreover, in Figures 11 and 12, the fuel filter 18 may not be provided, and only the storage portion 59 may be provided. This makes it possible to have a configuration in which fuel can be identified with the minimum necessary configuration.

[0068] This configuration allows the fuel filter 18 and the identification sensor 10 to be efficiently positioned according to the situation. Furthermore, the fuel filter 18 (device) can be easily attached to the fuel passage section 58. Since the fuel filter 18 is provided in the fuel passage section 58 through which fuel flows, the fuel filter 18 can accurately remove foreign matter from the fuel.

[0069] Furthermore, as shown in Figure 13, the base portion 55 may also include a fuel passage portion 58 and a storage portion 59. The fuel passage portion 58 is a member that forms a fuel inlet 46 and a fuel outlet 45, and forms a flow path through which fuel flows in from the fuel inlet 46 and is discharged from the fuel outlet 45. The storage portion 59 is an optional member provided in the fuel passage portion 58 for storing fuel. The mounting portion 56 for attaching the fuel filter 18 to the base portion 55 may be provided in the storage portion 59. In other words, the fuel filter 18 is provided in the base portion 55 via the mounting portion 56 of the fuel passage portion 58.

[0070] This configuration allows the fuel filter 18 and the identification sensor 10 to be efficiently positioned according to the situation. Furthermore, the fuel filter 18 (device) can be easily attached to the storage section 59. Since the fuel filter 18 is provided in the storage section 59 where the fuel is stored, the fuel filter 18 can accurately remove foreign matter from the fuel.

[0071] (4) In each of the above embodiments, the identification sensor 10 may be provided in multiple locations, not just one. This allows for more accurate identification of the fuel. Furthermore, the identification sensor 10 is not limited to being provided in the supply pipe 13, but may be provided at one or more arbitrary locations in the fuel flow pipe 12. For example, the identification sensor 10 may be provided in either the supply pipe 13 or the return pipe 14, or both. Also, the identification sensor 10 is not limited to being provided between the fuel tank 8 and the fuel filter 18, but may be provided in either the supply pipe 13 between the fuel tank 8 and the fuel filter 18, or between the fuel filter 18 and the engine 6 (location 22), or both. This allows for more flexibility in the placement of the identification sensor 10 while enabling accurate identification of the fuel.

[0072] (5) In each of the above embodiments, the fuel filter 18 may not be provided in the fuel flow pipe 12, the sub-tank 38, or the base unit 55. Alternatively, the fuel flow pipe 12 may be provided with other equipment that performs a predetermined operation (equipment having a predetermined function) instead of the fuel filter 18. Furthermore, a branch pipe 15 may be provided between the equipment and the return pipe 14, and fuel may flow from the equipment to the return pipe 14 via the branch pipe 15, or a branch pipe 15 may not be provided between the equipment and the return pipe 14.

[0073] This allows for easy identification of fuel while providing equipment that performs predetermined operations in the fuel flow pipe 12. Furthermore, the equipment can suppress foreign matter originating from the identification sensor 10, etc., from flowing with the fuel, thereby preventing foreign matter from entering the engine 6.

[0074] (6) In each of the above embodiments, the implement may be an agricultural implement such as a rice transplanter 2 or a tractor 3, or a construction implement, and may also be various engine-driven equipment driven by an engine 6 such as an engine generator or an engine compressor. In other words, the implement may be any self-propelled engine-driven equipment such as an agricultural implement or a construction implement, or it may be a stationary (portable) engine-driven equipment.

[0075] The present invention can be applied to various engine-driven work machines.

[0076] 6 Engine 10 Identification Sensor 24 Measurement Unit 25 Calculation Unit 27 Information Terminal (Display Device / Warning Unit) 29 Control Unit 31 Lamp (Warning Unit) 32 Speaker (Warning Unit) 34 Judgment Unit 35 Warning Control Unit 51 Measurement Information 52 Identification Information

Claims

1. A work machine comprising: an engine capable of being driven by each of several types of fuel, including carbon-neutral fuel; an identification sensor that identifies the type of carbon-neutral fuel and outputs identification information; and a display device that acquires and displays the identification information output by the identification sensor.

2. The work machine according to claim 1, wherein the identification sensor comprises a measuring unit that acquires predetermined information relating to the fuel, and a calculation unit that performs calculations to identify the fuel based on the information and outputs the identification information.

3. The work machine according to claim 1 or 2, where the fuel is a mixture of a plurality of carbon-neutral fuels, the identification information includes at least one of the types of carbon-neutral fuels to be mixed, the mixing ratio of the carbon-neutral fuels, and the carbon dioxide reduction effect.

4. The work machine according to claim 1 or 2, comprising: a warning unit that issues a predetermined warning; a determination unit that determines whether or not the warning is necessary according to the identification information; and a warning control unit that causes the warning unit to issue the warning according to the determination unit's determination.

5. The work machine according to claim 4, wherein, if the fuel is a mixture of a plurality of carbon-neutral fuels, the identification information is the mixing ratio of the carbon-neutral fuels, and the determination unit determines that the warning is necessary if the mixing ratio is outside a predetermined range.

6. The work machine according to any one of claims 1 to 5, further comprising a control unit for controlling the operation of the engine, wherein the control unit stops the engine when the identification information is in a predetermined state.