Fuel abnormality determination method and determination device for engine-driven work machine

Abstract

A prescribed characteristic value (for example, ultrasonic propagation speed) of a fuel in use detected at any position (fuel tank 80) of a fuel supply system is acquired (S3) as a fuel characteristic value Y, and is compared (S5) with a fuel characteristic reference range (Ymin-Ymax), which is a range of a normal value of the characteristic value (ultrasonic propagation speed) of the fuel for use stored in advance in a storage means 21. As a result of the comparison, when the fuel characteristic value Y is out of range (Y < Ymin or Y > Ymax) of the fuel characteristic reference range (Ymin-Ymax) of the fuel for use (NO in S6), it is determined (S9) that fuel abnormality such as mixing of different types of fuel or deterioration with time has occurred in the fuel in use in an engine-driven work machine, a warning notification is issued (S10), and the operation of the engine is limited (S11).

Description

Method and device for determining fuel abnormality in engine-driven work equipment

[0001] The present invention relates to a fuel abnormality determination method and a fuel abnormality determination device for an engine-driven working machine, and more specifically to a fuel abnormality determination method for an engine-driven working machine that determines if the fuel being used in the engine-driven working machine has become abnormal due to, for example, mixing of different types of fuel or deterioration over time, and a fuel abnormality determination device that executes the determination method.

[0002] As society becomes more concerned about environmental issues, the civil engineering and construction industry is also being called upon to decarbonize, and there is a growing demand to reduce the amount of carbon dioxide emitted by engine-driven power generators, compressors, and other engine-driven work machinery that are often used in the civil engineering and construction industries.

[0003] In response to these demands, there is a social demand for a switch from diesel fuel to diesel alternatives, such as fuels that emit less carbon dioxide than diesel, such as blended fuels such as B5 diesel fuel, which is diesel fuel with 5% or less of biodiesel added, B100 fuel, which is 100% biodiesel fuel, and GTL fuel, which is fuel refined from natural gas.

[0004] Here, under the Local Tax Act, B5 diesel, which is treated as diesel or light oil, is subject to diesel transaction tax, while B100 fuel and GTL fuel are not subject to tax.

[0005] On the other hand, if a mixed fuel produced by mixing diesel or B5 diesel with B100 fuel or GTL fuel is considered "diesel" under the Local Tax Act, it is also subject to diesel transaction tax. Therefore, for example, if B100 fuel or GTL fuel is mistakenly filled with fuel when diesel or B5 diesel remains in the fuel tank, or if diesel or B5 diesel is mistakenly filled with fuel when B100 fuel or GTL fuel remains in the fuel tank, and these fuels are mixed in the fuel tank to produce a mixed fuel that is considered "diesel" under the Local Tax Act, the "consumption" of the mixed fuel produced in this way is subject to diesel transaction tax as stipulated in the Local Tax Act (Article 144-3, Item 5 of the Local Tax Act), and therefore the "consumption" of the above-mentioned mixed fuel without paying diesel transaction tax is illegal.

[0006] Therefore, the mixing of other fuels into diesel and B5 diesel should be strictly prevented.

[0007] In addition, so-called "illegal diesel" - diesel mixed with other fuels such as kerosene for the purpose of evading diesel transaction tax - is also in circulation. If a person purchases fuel believing it to be diesel or biodiesel fuel, but it turns out to be such illegal diesel, they may end up using such illegal diesel unintentionally.

[0008] Therefore, in today's world where corporate compliance is strongly required, if a different type of fuel is mixed with diesel or B5 diesel in the fuel tank, or if a fuel (mixed fuel) of a type different from the type of fuel recognized by the operator is filled, there is a demand for a system that can prevent the consumption of such mixed fuel (illegal diesel) by, for example, automatically disabling the engine from starting.

[0009] Furthermore, fuel has a recommended usage period; for example, for diesel, this recommended usage period is approximately six months. However, there are engine-driven work machines that are not normally used and are stored in a stopped state for relatively long periods, such as engine-driven generators that are installed as backup power sources in the event of a disaster, and it is possible that the fuel stored in the fuel tank may have been stored for a long period beyond the recommended usage period.

[0010] In this way, fuel stored for a long period beyond the recommended usage period may have changed properties due to oxidation, etc., and using fuel with such changed properties may not only cause poor combustion, but may also cause malfunctions in the engine or fuel supply system.

[0011] Therefore, it is necessary to take measures to prevent engine-driven working machines from starting even when the fuel stored in the fuel tank of the engine-driven working machine has become abnormal, such as changing its properties due to long-term storage.

[0012] In response to these demands, it would be convenient if the system could automatically detect any abnormalities (fuel abnormalities) in the fuel being supplied to engine-driven work equipment, such as the mixing of different fuels or changes in properties due to deterioration over time, and take measures such as restricting the starting of the engine.

[0013] Although this does not determine fuel abnormalities as described above, Patent Document 1, which is cited below, proposes that a vehicle be equipped with a biofuel identification device that can identify the type of biofuel and the mixture ratio of diesel and biofuel in order to control post-injection during regeneration of a diesel particulate filter according to the mixture ratio of biofuel.

[0014] This biofuel identification device is equipped with a fuel oxygen concentration detection means that detects the oxygen concentration in the fuel supplied to the combustion device, and a heat value acquisition means that acquires the heat value of the fuel per process.Based on previously acquired correspondence relationships between the oxygen concentration in the fuel and the blending ratio of biofuel to diesel, and between the heat value and the blending ratio of biofuel to diesel, the device compares the blending ratio based on the detected oxygen concentration in the fuel with the blending ratio based on the acquired fuel heat value, and identifies the biofuel type for which the two blending ratios approximately match as the biofuel type in use, and also identifies that blending ratio as the biofuel blending ratio in the biofuel-blended diesel ([Claim 1] of Patent Document 1).

[0015] Japanese Patent Application Publication No. 2011-149297

[0016] The biofuel identification device introduced in the aforementioned Patent Document 1 can automatically identify the type of biofuel in the fuel being used and the mixing ratio of biofuel to diesel. However, since the type of biofuel and the mixing ratio of diesel to biofuel are identified when the type of fuel being used is completely unknown, in order to make these identifications, it is always necessary to have a means for detecting the oxygen concentration in the fuel and to obtain the heat value of the fuel per process, and so identification must be made by combining multiple characteristics of the fuel, which requires a complex device configuration, complex calculation processing, etc.

[0017] In particular, to identify the type of biofuel, it is necessary to acquire the fuel oxygen concentration-mixing ratio characteristics and the heat value-mixing ratio characteristics for each type of biofuel, which further complicates the device configuration and detection processing.

[0018] Furthermore, although the configuration described in the aforementioned Patent Document 1 is capable of detecting the type of biofuel and the mixing ratio of diesel and biofuel, it is not capable of determining the occurrence of fuel abnormalities such as the mixing of different fuels or deterioration over time that occurs in diesel, B5 diesel, B100 fuel, GTL fuel, etc.

[0019] Therefore, it is desirable to be able to determine, with a relatively simple device configuration, when an abnormality occurs in the fuel being used in an engine-driven working machine.

[0020] Therefore, the present invention has been made to eliminate the drawbacks of the above-mentioned conventional technology, and aims to provide a fuel abnormality determination method for engine-driven working machines that can determine if a fuel abnormality has occurred in the fuel used in the engine-driven working machine, such as the mixing of a different type of fuel or a change in properties due to deterioration over time, and a fuel abnormality determination device for engine-driven working machines that executes the determination method.

[0021] The means for solving the problems will be described below together with the reference numerals used in the description of the embodiment of the invention. These reference numerals are used to clarify the correspondence between the description of the claims and the description of the embodiment of the invention, and needless to say, are not used to restrict the interpretation of the technical scope of the present invention.

[0022] In order to achieve the above object, the fuel abnormality determination method for an engine-driven working machine 1 of the present invention is a fuel abnormality determination method for an engine-driven working machine 1 including an engine 70 that is a diesel engine and a working machine main body (not shown) driven by the engine 70, comprising: a normal range of a predetermined characteristic value of the fuel (ultrasonic wave propagation velocity in the embodiment) is set as a fuel characteristic reference range for the fuel; any one type of fuel selected from diesel and diesel alternative fuels as the fuel to be used in the engine-driven working machine 1 is set as the used fuel; and the fuel characteristic reference range (Ymin to Ymax) of the used fuel is stored in advance in storage means 21; and a fuel characteristic value acquisition process is performed to acquire, as a fuel characteristic value Y, the predetermined characteristic value (ultrasonic wave propagation velocity in the embodiment) of the fuel in use detected at any position in a fuel supply system that supplies fuel to the engine 70 (fuel tank 80 in the embodiment) (see S3 in FIG. 3 ); The method includes a fuel characteristic value comparison process (see S5 in FIG. 3) that compares the fuel characteristic value Y acquired in the fuel characteristic value acquisition process with the fuel characteristic reference range (Ymin to Ymax) of the used fuel stored in the storage means 21, and a fuel state determination process (see NO in S6 in FIG. 3 → S9) that determines that there is a fuel abnormality when the fuel characteristic value Y is outside the fuel characteristic reference range (Ymin to Ymax) of the used fuel (Y<Ymin or Y>Ymax) as a result of the fuel characteristic value comparison process (see NO in S6 → S9 in FIG. 3) (claim 1).

[0023] The method may be configured such that the fuel to be used can be selected from a group of target fuels consisting of a pre-specified group of multiple types of fuel, and the fuel characteristic reference ranges of each of the target fuels to be selected are stored in the storage means 21 in advance, and a fuel to be used setting process (see S2 in Figure 3) is further included in which any one of the target fuels to be selected is set as the fuel to be used, and in the fuel characteristic value comparison process (see S5 in Figure 3), the fuel characteristic value Y acquired in the fuel characteristic value acquisition process is compared with the fuel characteristic reference range of the fuel set as the fuel to be used in the fuel to be used setting process, among the fuel characteristic reference ranges of each of the fuels stored in the storage means 21, as the fuel characteristic reference range of the fuel to be used (claim 2).

[0024] Furthermore, in the case where the aforementioned fuel characteristic value changes in accordance with a change in fuel temperature X, it is preferable that the storage means 21 stores a correspondence relationship between a change in the fuel characteristic reference range and a change in the fuel temperature, and that the system further includes a fuel temperature acquisition process (see S4 in FIG. 3) for acquiring a fuel temperature X detected at any position (the fuel tank 80 in this embodiment) in a fuel supply system that supplies fuel to the engine 70, and that the fuel characteristic value comparison process (see S5 in FIG. 3) compares the fuel characteristic reference range (Ymin to Ymax) corresponding to the fuel temperature X acquired in the fuel temperature acquisition process, among the fuel characteristic reference ranges of the used fuel stored in the storage means 21, with the fuel characteristic value Y acquired in the fuel characteristic value acquisition process (claim 3).

[0025] In any of the fuel abnormality determination methods described above, it is preferable to further include an operational control process that, when a fuel abnormality is determined in the fuel state determination process (see S9 in Figure 3), notifies the determination result ("notifies a warning" in S10 in Figure 3) and / or restricts starting of the engine or performs an emergency stop (S11 in Figure 3) (claims 4 and 5).

[0026] Furthermore, the fuel abnormality determination device 10 for an engine-driven working machine 1 of the present invention is a fuel abnormality determination device 10 for an engine-driven working machine 1 that includes an engine 70 that is a diesel engine and a working machine main body (not shown) that is driven by the engine 70, and includes: a used fuel that is any one type of fuel selected from diesel and diesel alternative fuels as the fuel to be used in the engine-driven working machine 1; a storage means 21 that stores in advance the fuel characteristic reference range (Ymin to Ymax) of the used fuel, where the normal range of a predetermined characteristic value of the fuel (ultrasonic wave propagation velocity in the embodiment) is set as the fuel characteristic reference range of the fuel; a fuel characteristic value acquisition means 22 that acquires, as a fuel characteristic value Y, the predetermined characteristic value (ultrasonic wave propagation velocity in the embodiment) of the fuel in use that is detected at any position (fuel tank 80 in the embodiment) of a fuel supply system that supplies fuel to the engine 70; and a fuel characteristic value comparison means 23 that compares the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 with the fuel characteristic reference range (Ymin to Ymax) of the used fuel stored in the storage means 21. The fuel state determination means 24 determines that a fuel abnormality exists when, as a result of comparison by the fuel characteristic value comparison means 23, the fuel characteristic value Y is outside the fuel characteristic reference range (Ymin to Ymax) of the fuel used (Y<Ymin or Y>Ymax) (claim 6).

[0027] In a configuration in which the used fuel can be selected from a group of pre-specified target fuels consisting of multiple types of fuel, the storage means 21 may store in advance the fuel characteristic reference ranges of each of the fuels constituting the target fuels, and may further include a used fuel setting means 25 that sets any one of the target fuels selected from the target fuels as the used fuel, and the fuel characteristic value comparison means 23 may compare the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 with the fuel characteristic reference range of the fuel set as the used fuel by the used fuel setting means 25, among the fuel characteristic reference ranges of each of the fuels stored in the storage means 21, as the fuel characteristic reference range (Ymin to Ymax) of the used fuel (Claim 7).

[0028] Furthermore, when a fuel characteristic value that changes with a change in fuel temperature X is used, the storage means 21 may store a correspondence relationship between a change in the fuel temperature X and a change in the fuel characteristic reference range, and a fuel temperature acquisition means 26 may be further provided that acquires the fuel temperature X detected at any position (fuel tank 80 in this embodiment) in a fuel supply system that supplies fuel to the engine 70, and the fuel characteristic value comparison means 23 may compare the fuel characteristic reference range (Ymin to Ymax) corresponding to the fuel temperature X acquired by the fuel temperature acquisition means 26, among the fuel characteristic reference ranges of the used fuel stored in the storage means 21, with the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 (claim 8).

[0029] Either of the fuel abnormality determination devices 10 having the above configurations may further include an operation control means 27 that, when a fuel abnormality is determined by the fuel state determination means 24, notifies the user of the determination result and / or restricts the start of or performs an emergency stop of the engine 70 (claims 9 and 10).

[0030] With the configuration of the present invention as described above, the fuel abnormality determination method and determination device 10 for the engine-driven working machine 1 of the present invention can provide the following significant effects.

[0031] In the present invention, the events to be judged are limited to "fuel abnormality," and regardless of the type of fuel actually being supplied to the engine-driven working machine 1, a fuel abnormality is judged on the assumption that the fuel being supplied to the engine-driven working machine is the "used fuel," which is any one type of fuel selected from diesel or diesel alternative fuel as the fuel to be used in the engine-driven working machine 1. Therefore, a fuel abnormality can be judged by the extremely simple method of determining whether the fuel characteristic value Y of the fuel in the fuel supply system is outside the fuel characteristic reference range (normal range) Ymin to Ymax of the used fuel stored in the memory means 21.

[0032] Furthermore, by determining whether a fuel abnormality exists based on whether the fuel characteristic value Y of the fuel in the fuel supply system is outside the fuel characteristic reference range (normal range) Ymin to Ymax of the fuel used stored in the memory means 21, it is possible to determine a fuel abnormality not only when the fuel characteristic value has changed due to the mixing of different fuels, but also when the fuel characteristic value has changed due to changes in the properties of the fuel over time (deterioration).

[0033] In a configuration in which the above-mentioned fuel to be used can be selected from a group of selectable fuels consisting of a pre-specified group of multiple types of fuel, the fuel characteristic reference ranges of each fuel constituting the selectable fuels are stored in the storage means 21, and the fuel to be used can be specified from the selectable fuels by the fuel to be used setting means 25, by comparing the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 with the fuel characteristic reference range (Ymin to Ymax) of the fuel of the oil type set as the fuel to be used by the fuel to be used setting means 25 from the fuel characteristic reference ranges of each fuel stored in the storage means 21, it is possible to easily determine a fuel abnormality even when the type of fuel to be used in the engine-driven working machine 1 can be set arbitrarily.

[0034] When determining whether a fuel abnormality exists based on a characteristic value that changes in accordance with a change in fuel temperature X, the correspondence relationship between the change in the fuel characteristic reference range and the change in fuel temperature X is stored in advance in the storage means 21, the fuel temperature X is detected and acquired, and the fuel abnormality is determined using the fuel characteristic reference range Ymin to Ymax that corresponds to the acquired fuel temperature X, thereby making it possible to accurately determine whether a fuel abnormality exists even if the fuel characteristic value changes in accordance with a change in fuel temperature X.

[0035] In addition, in a configuration provided with an operation control means 27 that notifies the operator of the result of a fuel abnormality when it is determined that there is a fuel abnormality and / or restricts or stops the engine from starting in an emergency, it is possible to easily notify the operator of the occurrence of a fuel abnormality and / or restrict or stop the engine from starting, thereby preventing the illegal consumption of illegal diesel fuel and malfunctions of the engine 70 due to the use of deteriorated fuel.

[0036] The fuel temperature and fuel characteristic reference ranges for each of the selectable fuels (diesel, GTL, B100) are shown in FIG. 1. The fuel temperature and fuel characteristic reference ranges are shown in FIG. 1. The fuel temperature and fuel characteristic reference ranges are shown in FIG. 1. The fuel temperature and fuel characteristic reference ranges are shown in FIG. 1. The fuel temperature and fuel characteristic reference ranges are shown in FIG. 1. The fuel abnormality determination device for an engine-driven work machine according to the present invention are functional block diagrams.

[0037] A fuel abnormality determination device 10 for an engine-driven working machine according to the present invention will be described below with reference to the accompanying drawings.

[0038] [Target Engine-Driven Working Machines] The fuel abnormality determination device 10 of the present invention can be installed on various types of engine-driven working machines 1, without any particular limitation, as long as the engine-driven working machine 1 is equipped with an engine 70 that is a diesel engine and a working machine main body (not shown) that is driven by the engine 70. Engine-driven generators, engine-driven compressors, engine-driven pumps, etc., as examples, can all be included as targets for engine-driven working machines 1 that are equipped with the fuel abnormality determination device 10 of the present invention.

[0039] In this embodiment, it is planned that the "fuel used," which is the fuel used by the engine-driven work machine 1, can be set by the operator to any type selected from the "selectable fuels" consisting of the group of diesel, GTL fuel, and B100 fuel, but the types of fuel that can be selected are not limited to the above examples, and it is also possible to select from a greater or fewer number of selectable fuels, and the above-mentioned selectable fuels may also include B5 diesel, which is commonly used as an alternative fuel to diesel in the construction industry.

[0040] Furthermore, the fuel abnormality determination device 10 of the present invention may be installed in an engine-driven working machine 1 in which the aforementioned "used fuel," which is the fuel used in the engine-driven working machine 1, is limited to only one type of fuel, for example, at the stage of shipping the engine-driven working machine 1 from the factory.

[0041] [Fuel Abnormality Determining Device] FIG. 1 shows an example of the configuration of a fuel abnormality determining device 10 for an engine-driven working machine 1 according to the present invention.

[0042] As shown in FIG. 1 , the fuel abnormality determination device 10 of this embodiment includes an electronic control device (control device 20) such as a microcontroller, detection devices such as a fuel characteristic value detection device 31 and a temperature detection device 32, input devices such as a fuel usage input device 41, and notification devices such as a warning display device 51 and an alarm device 52, which are formed by a monitor screen or the like for notifying an operator of a fuel abnormality, as well as a storage device 21, a fuel usage setting device 25, a fuel characteristic value acquisition device 22, a fuel temperature acquisition device 26, a fuel characteristic value comparison device 23, a fuel state determination device 24, an operation control device 27, and the like, which are realized in the control device 20 described above.

[0043] (1) Storage Means The storage means 21 stores, as a fuel characteristic reference range, reference values ​​(a range of normal values) required to determine whether or not an abnormality has occurred in the fuel, based on the characteristic values ​​of the fuel in use detected by the fuel characteristic value detection means 31 described later.

[0044] In the configuration of this embodiment, an ultrasonic sensor is provided as the fuel characteristic value detection means 31, and the ultrasonic propagation velocity of the fuel detected by this ultrasonic sensor is acquired as the fuel characteristic value Y by the fuel characteristic value acquisition means 22 described below.The range of normal values ​​of the ultrasonic propagation velocity of the fuel used is stored in the storage means 21 as the above-mentioned fuel characteristic reference range (Ymin to Ymax).

[0045] When the fuel used in the engine-driven working machine 1 (fuel used) is limited in advance to only one type, it is possible to store only the fuel characteristic reference range (Ymin to Ymax) of that one type of fuel. However, in the configuration of the determination device 10 of this embodiment, which is configured so that any one type of fuel selected from the group of selectable fuels consisting of diesel, GTL fuel, and B100 fuel can be set as the fuel used, the fuel characteristic reference range (Ymin to Ymax) of each of the fuels (diesel, GTL fuel, and B100 fuel) that make up the selectable fuels is stored in the storage means 21, as shown in Figure 2.

[0046] In this embodiment, the ultrasonic propagation velocity, which causes a change in the characteristic value of the fuel in accordance with a change in the fuel temperature X, is used as the characteristic value of the fuel. As shown in FIG. 2, the correspondence relationship between the change in the fuel temperature X and the change in the reference range of the fuel characteristic is also stored in advance in the storage means.

[0047] However, if the characteristic value of the fuel used for comparison does not change depending on the change in the fuel temperature X, it is not necessary to store the change in the fuel characteristic reference range in response to the change in the fuel temperature X in the storage means.

[0048] Furthermore, in this embodiment, an example will be described in which the ultrasonic propagation velocity is used as the characteristic value of the fuel used in the comparison. However, the characteristic value of the fuel used in the comparison is not limited to the ultrasonic propagation velocity, and various other characteristic values ​​such as the electrostatic capacitance or thermal conductivity of the fuel can be used, and a combination of two or more of these may also be used.

[0049] In this case, two or more fuel characteristic reference ranges are stored in the storage means 21 in accordance with the characteristic values ​​to be used in combination.

[0050] (2) Fuel to be used setting means The fuel to be used setting means 25 executes a fuel to be used setting process, in which the operator uses a fuel to be used input means 41 such as a touch panel provided on the engine-driven working machine to select and input one of the aforementioned selectable fuels (in this embodiment, diesel, GTL fuel, and B100 fuel) as the aforementioned “fuel to be used” to be used by the engine-driven working machine 1. If the fuel to be used (fuel to be used) by the engine-driven working machine 1 is limited to one type in advance, the fuel to be used setting means 25 and the aforementioned fuel to be used input means 41 do not need to be provided.

[0051] In this embodiment, in which diesel, GTL fuel, and B100 fuel are set as the fuels to be selected as described above, when the operator selects the type of oil by touching one of the displays "diesel," "GTL," and "B100" (for example, "diesel") displayed on the touch panel, which is the fuel to be used 41 described above, the fuel to be used setting means 25, which receives a signal from the fuel to be used input means (touch panel) 41, sets the type of oil as the fuel to be used by temporarily storing the selection result made by the operator on the touch panel 41 (for example, selection of diesel).

[0052] When changing the fuel to be used, the operator selects a new oil type (e.g., B100) from the oil types displayed on the fuel to be used input means (touch panel) 41, and the fuel to be used setting means 25 updates the selection result of the oil type (e.g., diesel) that was temporarily stored to the selection result of the newly selected oil type (e.g., B100), thereby changing the specified oil type.

[0053] (3) Fuel characteristic value acquisition means The fuel characteristic value acquisition means 22 receives the fuel characteristic value of the fuel in use detected by the fuel characteristic value detection means 31 provided at any position in the fuel supply system, and acquires this as the fuel characteristic value Y, thereby executing a fuel characteristic value acquisition process.

[0054] In the embodiment shown in FIG. 1 , an ultrasonic sensor is provided as the fuel characteristic value detection means 31 in a fuel tank 80 that constitutes a fuel supply system, and the ultrasonic propagation velocity of the fuel detected by the ultrasonic sensor 31 can be acquired by the fuel characteristic value acquisition means 22 as the fuel characteristic value Y.

[0055] However, as described above, a capacitance sensor or a thermal conductivity sensor may be provided as the fuel characteristic value detection means 31 to detect the capacitance or thermal conductivity of the fuel, and the capacitance or thermal conductivity detected in this manner may be acquired by the fuel characteristic value acquisition means 22 as the fuel characteristic value Y. Furthermore, the fuel characteristic value Y to be acquired may not be just one of the above-mentioned values, but may be a combination of multiple values.

[0056] (4) Fuel Temperature Acquisition Means The fuel temperature acquisition means 26 executes a fuel temperature acquisition process to acquire the fuel temperature X by receiving a detection signal of the fuel temperature X in the fuel supply system detected by a fuel temperature detection means 32 provided at any position in the fuel supply system that supplies fuel to the engine 70.

[0057] The fuel temperature detection means 32 may be provided at any position in the fuel supply system, but is preferably provided at the same position as the fuel characteristic value detection means 31 described above, thereby making it possible to acquire the characteristic value and fuel temperature X of the fuel at the same position.

[0058] In this embodiment, together with the ultrasonic sensor which is the fuel characteristic value detection means 31 described above, a temperature sensor is provided as the fuel temperature detection means 32 described above at a common position in the fuel tank 80, so that the fuel temperature X inside the fuel tank 80 can be detected and the fuel temperature X detected by the temperature sensor 32 can be acquired by the fuel temperature acquisition means 26 described above as the fuel temperature X.

[0059] The fuel temperature acquisition means 26 and the fuel temperature detection means 32 are components that are necessary when a characteristic value that changes with a change in the fuel temperature X is used as the aforementioned fuel characteristic value, and do not need to be provided when a characteristic value that does not change with a change in the fuel temperature X is used to determine a fuel abnormality.

[0060] (5) Fuel characteristic value comparison means The fuel characteristic value comparison means 23 executes a fuel characteristic value comparison process to compare the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 described above with the fuel characteristic reference range (Ymin to Ymax) of the fuel used stored in the storage means 21.

[0061] In this embodiment, the fuel to be used in the engine-driven working machine 1 is set to any one type of fuel selected from a group of selectable fuels consisting of diesel, GTL fuel, and B100 fuel, and the ultrasonic propagation velocity, which changes with changes in fuel temperature X, is adopted as the fuel characteristic value to be used in comparison.The fuel characteristic value comparison means 23 calculates a fuel characteristic reference range Ymin to Ymax at the detected fuel temperature X for the oil type set as the fuel to be used, based on the setting result of the fuel to be used set by the fuel to be used setting means 25, the fuel temperature X acquired by the fuel temperature acquisition means 26, and the correlation between the fuel temperature and the fuel characteristic reference range of the selectable fuel stored in the storage means 21 (see FIG. 2), and compares the calculated fuel characteristic reference range Ymin to Ymax with the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22.

[0062] For example, if the type of oil set as the fuel to be used by the fuel to be used setting means 25 is B100 fuel and the fuel temperature X acquired by the fuel temperature acquisition means 26 is 30°C, the fuel characteristic value comparison means 23 calculates a fuel characteristic reference range (see Figure 2) consisting of a lower limit value indicated by Ymin (B100 / 30°C) and an upper limit value indicated by Ymax (B100 / 30°C) based on the correlation between the fuel temperature of the selected fuel and the fuel characteristic reference range stored in the storage means 21, and compares this with the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22.

[0063] (6) Fuel State Determination Means The fuel state determination means 24 executes a fuel state determination process to determine that there is a fuel abnormality when, as a result of comparison by the fuel characteristic value comparison means 23, the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 is outside the range of the fuel characteristic reference range [Ymin to Ymax: in the above example, Ymin (B100 / 30°C) to Ymax (B100 / 30°C)] (Y<Ymin, or Y>Ymax).

[0064] (7) Operation Control Means When the fuel state determination means 24 determines that a fuel abnormality has occurred, the operation control means 27 executes an operation control process to control the operation of each part of the engine-driven working machine 1 in response to this.

[0065] Specifically, when a fuel abnormality is determined, one or a combination of the following engine operation control processes is performed: notification processes such as turning on a warning light or displaying a warning on a monitor screen or other warning display means 51, sounding a warning sound from an alarm 52, outputting a control signal to an engine control unit (ECU) 71, etc., starting restriction that makes it impossible to start the engine 70 if the engine 70 is stopped, or emergency stop that stops the engine 70 if the engine 70 is running, and in this embodiment, all of the above processes are performed.

[0066] (8) Others (fuel type determination means) As described above, in the configuration of the fuel abnormality determination device 10 for the engine-driven working machine 1 of this embodiment, which is capable of setting any one type of fuel selected from the selectable fuels previously set by the fuel use setting means 25 as the fuel to be used, in addition to the means described above, a fuel type determination means 28 may also be provided.

[0067] This fuel type determination means 28 executes a fuel type determination process in which it compares the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 with the fuel characteristic reference range Ymin to Ymax of each fuel constituting the fuel to be selected, which is stored in the storage means, and determines that an oil type that includes the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 within the fuel characteristic reference range Ymin to Ymax is the fuel currently in use.

[0068] In the configuration of this embodiment, in which the determination is made using the ultrasonic propagation velocity, whose characteristic value changes with a change in fuel temperature X, as the fuel characteristic value, the fuel type determination means 28 calculates the fuel characteristic reference range (normal range) Ymin to Ymax of each selection target fuel at the fuel temperature X acquired by the fuel temperature acquisition means 26, based on the fuel temperature X acquired by the fuel temperature acquisition means 26 and the correlation between the fuel temperature and the fuel characteristic reference range of the selection target fuel stored in the storage means 21 (see FIG. 2 ), and compares this with the fuel characteristic value Y acquired by the fuel characteristic value acquisition means.

[0069] The fuel type determination means 28 may further display the determination result on a monitor screen or the like, which is the determination result display means 55 .

[0070] In this way, by providing the fuel type determination means 28, even if the type of fuel currently being used in the engine-driven work machine 1 becomes unknown because, for example, the type of fuel being used was not communicated when the operator was changed, the operator can predict the fuel currently being used based on the determination result of the fuel type determination means 28.

[0071] However, in order for the fuel type determination means 28 to make an accurate determination, it is necessary that the fuel stored in the fuel tank of the engine-driven work machine 1 does not have any abnormalities such as mixing of different types of fuel or deterioration over time.If the fuel characteristic values ​​have changed due to such fuel abnormalities (mixing of multiple oil types or deterioration over time), it may not be possible to accurately determine the fuel type.

[0072] (9) Operation, etc. The operation of the fuel abnormality determination device 10 for the engine-driven working machine 1 of the present invention, which has been described above with reference to FIG. 1, will now be described with reference to FIG.

[0073] When the control power supply (ACC power supply) is turned ON (S1) by operating a key switch (not shown) provided on the engine-driven working machine 1, power supply to the electrical equipment (including the control device 20) provided on the engine-driven working machine 1 begins.

[0074] In this state, when the operator selects the type of oil on the fuel to be used input means 41, such as a touch panel, provided on the engine-driven work machine 1, the selection made by the operator is temporarily stored and the selected type of oil is set as the fuel to be used in the fuel to be used setting means 25 (S2).

[0075] Furthermore, when the control power supply is turned ON, the fuel characteristic value detection means (ultrasonic sensor) 31 starts detecting the characteristic value (ultrasonic wave propagation velocity) of the fuel in the fuel supply system (fuel tank 80), and the detected fuel characteristic value (ultrasonic wave propagation velocity of the fuel) is acquired by the fuel characteristic value acquisition means 22 as the fuel characteristic value Y (S3).

[0076] Furthermore, the fuel temperature detection means (temperature sensor) 32 detects the fuel temperature X in the fuel supply system (fuel tank 80), and the detected fuel temperature X is acquired as the fuel temperature X by the fuel temperature acquisition means 26 (S4).

[0077] Once the fuel characteristic value acquisition means 22 has acquired the fuel characteristic value Y and the fuel temperature acquisition means 26 has acquired the fuel temperature X in this manner, the fuel characteristic value comparison means 23 is activated and compares the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 with the fuel characteristic reference range (Ymin to Ymax) stored in the storage means 21 (S5).

[0078] The comparison of fuel characteristic values ​​in the fuel characteristic value comparison means 23 is performed by calculating a fuel characteristic reference range Ymin to Ymax at the acquired fuel temperature X for the oil type set as the fuel to be used, based on the correlation between the fuel temperature and the fuel characteristic reference range of the selected fuel stored in the storage means 21 (see FIG. 2 ), and comparing the calculated fuel characteristic reference range Ymin to Ymax with the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22.

[0079] As an example, if the oil type set by the fuel use setting means 25 is B100 fuel and the fuel temperature X acquired by the fuel temperature acquisition means is 30°C, the fuel characteristic value comparison means 23 calculates a fuel characteristic reference range with Ymin (B100 / 30°C) in Figure 2 as the lower limit and Ymax (B100 / 30°C) as the upper limit, and compares this with the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 (S5).

[0080] In this way, based on the comparison by the fuel characteristic value comparison means 23, if the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 is within the aforementioned fuel characteristic standard range (Ymin≦Y≦Ymax) (YES in S6), the fuel state determination means 24 determines that the fuel is in a normal state (S7), and the engine-driven work machine can be operated as usual (S8).

[0081] On the other hand, if the fuel characteristic value Y acquired by the fuel characteristic value acquisition means 22 is outside the aforementioned fuel characteristic reference range (Y<Ymin or Y>Ymax) (NO in S6), the fuel state determination means 24 determines that a fuel abnormality has occurred (S9), and the operation control means 27 issues an alarm such as a warning display by the warning display means 51 or an alarm sound by the alarm 52 (S10), and if the engine has not started, it performs a start restriction to prevent the engine from starting, or if the engine is running, it performs an emergency stop of the engine (S11), thereby preventing the consumption of illegal fuel or the use of deteriorated fuel, and this operation continues until the control power supply is turned off (S12).

[0082] REFERENCE SIGNS LIST 1 Engine-driven work machine 10 Fuel abnormality determination device 20 Control device 21 Storage means 22 Fuel characteristic value acquisition means 23 Fuel characteristic value comparison means 24 Fuel state determination means 25 Used fuel setting means 26 Fuel temperature acquisition means 27 Operation control means 28 Fuel type determination means 31 Fuel characteristic value detection means (ultrasonic sensor) 32 Fuel temperature detection means (temperature sensor) 41 Used fuel input means (touch panel) 51 Warning display means 52 Alarm 55 Determination result display means (monitor screen) 70 Engine 71 Engine control unit (ECU) 80 Fuel tank

Claims

1. A method for determining a fuel abnormality in an engine-driven working machine having a diesel engine and a working machine body driven by the engine, comprising: a fuel characteristic value acquisition process which sets a normal range of a predetermined characteristic value of the fuel as a fuel characteristic reference range for the fuel, selects one type of fuel selected from diesel and diesel alternative fuels as the fuel to be used in the engine-driven working machine, and stores the fuel characteristic reference range for the used fuel in advance in a storage means, and acquires, as a fuel characteristic value, the predetermined characteristic value of the fuel in use detected at any position in a fuel supply system that supplies fuel to the engine; a fuel characteristic value comparison process which compares the fuel characteristic value acquired in the fuel characteristic value acquisition process with the fuel characteristic reference range for the used fuel stored in the storage means; and a fuel state determination process which determines that a fuel abnormality has occurred when the fuel characteristic value is outside the fuel characteristic reference range for the used fuel as a result of the fuel characteristic value comparison process.

2. A fuel abnormality determination method for an engine-driven working machine as described in claim 1, characterized in that the used fuel is selectable from a group of selection target fuels consisting of a pre-specified group of multiple types of fuel, the fuel characteristic standard range of each fuel constituting the selection target fuel is pre-stored in the memory means, and the method further includes a used fuel setting process for setting any one of the selection target fuels as the used fuel, and in the fuel characteristic value comparison process, the fuel characteristic value acquired in the fuel characteristic value acquisition process is compared with the fuel characteristic standard range of the fuel set as the used fuel in the used fuel setting process among the fuel characteristic standard ranges of each of the fuels stored in the memory means as the fuel characteristic standard range of the used fuel.

3. A method for determining a fuel abnormality in an engine-driven working machine as described in claim 1 or 2, characterized in that the corresponding relationship of changes in the fuel characteristic reference range to changes in fuel temperature is stored in the memory means, and the method further includes a fuel temperature acquisition process for acquiring a fuel temperature detected at any position in a fuel supply system that supplies fuel to the engine, and in the fuel characteristic value comparison process, the fuel characteristic reference range of the used fuel stored in the memory means that corresponds to the fuel temperature acquired in the fuel temperature acquisition process is compared with the fuel characteristic value acquired in the fuel characteristic value acquisition process.

4. A fuel abnormality determination method for an engine-driven working machine as described in claim 1 or 2, further comprising an operational control process for notifying the determination result and / or restricting the start of the engine or performing an emergency stop when a fuel abnormality is determined in the fuel state determination process.

5. A fuel abnormality determination method for an engine-driven working machine as described in claim 3, further comprising an operational control process for notifying the determination result and / or restricting the start of the engine or performing an emergency stop when a fuel abnormality is determined in the fuel state determination process.

6. A fuel abnormality determination device for an engine-driven working machine having a diesel engine and a working machine body driven by the engine, comprising: a fuel used is any one type of fuel selected from diesel and diesel alternative fuels as the fuel to be used in the engine-driven working machine, a storage means for storing in advance the fuel characteristic standard range of the used fuel, a normal range of a predetermined characteristic value of the fuel being determined as a fuel characteristic value of the fuel, a fuel characteristic value acquisition means for acquiring, as a fuel characteristic value, the predetermined characteristic value of the fuel in use detected at any position in a fuel supply system that supplies fuel to the engine, a fuel characteristic value comparison means for comparing the fuel characteristic value acquired by the fuel characteristic value acquisition means with the fuel characteristic standard range of the used fuel stored in the storage means, and a fuel state determination means for determining that a fuel abnormality has occurred when the fuel characteristic value is outside the fuel characteristic standard range of the used fuel as a result of the comparison by the fuel characteristic value comparison means.

7. A fuel abnormality determination device for an engine-driven working machine as described in claim 6, characterized in that the used fuel is selectable from a group of pre-specified selection target fuels consisting of a plurality of types of fuel, the fuel characteristic base ranges of each of the selection target fuels are pre-stored in the memory means, and a used fuel setting means is further included which sets any one of the selection target fuels as the used fuel, and the fuel characteristic value comparison means compares the fuel characteristic value acquired by the fuel characteristic value acquisition means with the fuel characteristic reference range of the fuel set as the used fuel by the used fuel setting means among the fuel characteristic reference ranges of each of the fuels stored in the memory means as the fuel characteristic reference range of the used fuel.

8. A fuel abnormality determination device for an engine-driven working machine as described in claim 6 or 7, characterized in that the memory means stores the corresponding relationship of changes in the fuel characteristic reference range relative to changes in fuel temperature, and further includes a fuel temperature acquisition means for acquiring a fuel temperature detected at any position in a fuel supply system that supplies fuel to the engine, and the fuel characteristic value comparison means compares the fuel characteristic reference range of the used fuel corresponding to the fuel temperature acquired by the fuel temperature acquisition means, among the fuel characteristic reference ranges of the used fuel stored in the memory means, with the fuel characteristic value acquired by the fuel characteristic value acquisition means.

9. A fuel abnormality determination device for an engine-driven working machine as described in claim 6 or 7, further comprising an operation control means for, when a fuel abnormality is determined by the fuel state determination means, notifying the determination result and / or restricting the start of the engine or performing an emergency stop.

10. A fuel abnormality determination device for an engine-driven working machine as described in claim 8, further comprising an operational control means for, when a fuel abnormality is determined by the fuel state determination means, notifying the result of the determination and / or restricting the start of the engine or performing an emergency stop.

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