JP2008267339A - Fuel managing device of construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent malfunction of an engine due to a disapproved fuel and reducing generation of defective exhaust gas by easily judging a fuel used by a construction machine and preventing use of the disapproved fuel. <P>SOLUTION: The fuel managing device mounted on the construction machine judges whether the fuel used for the engine is usable or not. The fuel managing device is provided with a detection means 6 having a concentration sensor 12 for outputting a signal according to the concentration of the fuel introduced in a fuel tank 21 or a fuel system of the construction machine 20, control means 5 or 14 for judging whether the concentration of the identified fuel detected by the concentration sensor 12 is within a predetermined range or not, an EGR (exhaust gas recirculation) 23 for recirculating the exhaust gas of the engine and an engine controller 11 for controlling the EGR 23 and judges whether the fuel concentration detected at a predetermined timing is within the predetermined range or not by the control means 5 or 14, derives a judgement signal to the engine controller 11 and controls the EGR 23 based on the judgement result. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel management device for a construction machine, and more particularly to a fuel management device that prevents the use of fuel other than light oil and reduces generated exhaust gas in a construction machine equipped with a diesel engine.

  Conventionally, construction machines such as hydraulic excavators, bulldozers, and road paving vehicles are equipped with diesel engines, and only diesel oil is allowed as the fuel. However, since kerosene or heavy oil can also be operated, kerosene or heavy oil with low fuel prices may be used in practice. Due to the use of these non-permitted fuels, problems such as engine failure and generation of defective exhaust gas are occurring.

  Recently, an engine that complies with the tertiary emission regulations has been developed, and it is required to clean the exhaust gas, and there is a growing need to prevent the use of unauthorized fuel in order to eliminate defective exhaust gas. Yes.

  As a device for identifying the type of fuel, there are a light projecting means for projecting a light signal of a predetermined light quantity on the fuel, and at least a part of the light signal after the light signal propagates through a predetermined light path in the fuel. A light receiving means for receiving, an electric circuit means for determining whether the light quantity is higher than a predetermined reference level in response to an optical signal received by the light receiving means, and a response to an output from the electric circuit means There is known a fuel discriminating device including display means for displaying the discrimination result in the electric circuit means (see, for example, Patent Document 1).

  The fuel discriminating apparatus discriminates the type of fuel based on the degree of attenuation of the amount of light while the optical signal projected to the fuel propagates through a predetermined optical path, that is, the difference in light transmittance. For example, there is a large difference in light transmittance between a fuel colored red such as gasoline and a fuel to be colored such as light oil, so that gasoline and other fuels can be reliably distinguished.

  There is also known a fuel discriminating device provided with a detecting means for detecting a chemical quantity or a physical quantity in a fuel tank and a discriminating means for discriminating the type of fuel based on the detection result of the detecting means (for example, Patent Document 2). reference).

The fuel discriminating apparatus stores in advance the measurement results of chemical quantity and physical quantity of liquid fuel that can be accommodated in the fuel tank, such as optical spectrum and electrical resistance, and collates the measured values of the detection means with the measurement results. By doing so, the type of liquid fuel is discriminated.
Japanese Utility Model Publication No. 2-71254 JP 2005-201068 A

  The invention described in Patent Document 1 discriminates the type of fuel based on the difference in the light transmittance of an optical signal projected onto the fuel, and has a clearly different light transmittance such as gasoline and light oil. Can be reliably identified, but it is difficult to accurately identify light oil and kerosene that do not have a large difference in light transmittance or when kerosene is mixed with light oil.

  The invention described in Patent Document 2 compares and collates the fuel specific chemical quantity and physical quantity stored in advance with the actual measurement value of the detection means. However, since the optical spectrum measuring device is expensive, the cost increases. It becomes a factor.

  Further, both Patent Documents 1 and 2 discriminate the type of fuel and prevent accidents due to an error in the type of fuel, but there is no particular description regarding the point of reducing the generated bad exhaust gas.

  Therefore, technical issues to be solved to easily determine the fuel used for construction machinery, prevent the use of unauthorized fuel, prevent engine failure due to unauthorized fuel, and reduce the generated exhaust gas The present invention aims to solve this problem.

  The present invention has been proposed to achieve the above object, and the invention according to claim 1 is a construction machine mounted on a construction machine for determining whether or not a fuel used for an engine of the construction machine can be used. In the fuel management device, the detecting means having a density sensor for outputting a signal corresponding to the density of the fuel introduced into the fuel tank or the fuel system of the construction machine, and the density of the identified fuel detected by the density sensor is predetermined. Is provided with control means for determining whether or not it is within the range, EGR (Exhaust Gas Recirculation) for recirculating the exhaust gas of the engine, and an engine controller for controlling the EGR, and the fuel density detected at a predetermined timing is It is determined by the control means whether it is within a predetermined range, the determination signal is derived to the engine controller, and the EGR is controlled based on the determination result A fuel discriminating apparatus Unishi were construction machine.

  According to this configuration, when the fuel density detected at a predetermined timing is outside the specified range with respect to the normal fuel density measured in advance, the controller cannot be used. When a determination signal is issued and the engine controller receives this determination signal, the amount of exhaust gas returned to the engine is limited by controlling an EGR valve or the like.

  According to a second aspect of the present invention, in the first aspect, the detection means includes a temperature sensor that detects the temperature of the identified fuel when the density sensor detects the fuel density, and the fuel detected at a predetermined timing. There is provided a fuel management device for a construction machine in which whether or not the density and the fuel temperature are within a predetermined range is determined by a control means, and EGR is controlled based on the determination result.

  According to this configuration, control is performed by determining whether both the density and temperature of the fuel to be identified are within a predetermined range.

  A third aspect of the present invention provides the fuel discrimination device for a construction machine according to the first or second aspect, wherein the engine controller controls the fuel injection amount to the engine based on the determination result instead of controlling the EGR. To do.

  According to this configuration, when the fuel density detected at a predetermined timing is outside the specified range with respect to the normal fuel density measured in advance, the control means cannot be used. When the engine controller receives this determination signal, the fuel injection device is controlled to limit the fuel injection amount to the engine.

  In the first aspect of the invention, when an unusable determination signal is issued based on the detected fuel density, the engine controller controls the EGR valve and the like to control the return amount of the exhaust gas to the engine. Deterioration and failure of EGR components due to the use of fuel can be prevented, and defective exhaust gas can be reduced.

  In addition to the effect of the invention of claim 1, the invention of claim 2 detects both the fuel density and the fuel temperature and determines whether or not the fuel density and the fuel temperature are within a predetermined range. More accurate control becomes possible.

  According to the third aspect of the present invention, when an unusable determination signal is issued based on the detected fuel density, the engine controller controls the fuel injection device to limit the amount of fuel injected into the engine. It is possible to prevent deterioration and failure of engine components due to use, and to reduce defective exhaust gas.

  In order to achieve the object of easily discriminating the fuel used in construction machinery, preventing the use of non-permitted fuel to prevent engine failure due to the non-permitted fuel, and reducing the generated exhaust gas. Is a fuel management device for a construction machine that is mounted on a construction machine and determines whether or not the fuel used for the engine of the construction machine can be used, according to the density of the fuel introduced into the fuel tank or fuel system of the construction machine A detecting means having a density sensor for outputting a signal, a control means for determining whether or not the density of the identified fuel detected by the density sensor is within a predetermined range, and an EGR (Exhaust) for recirculating the exhaust gas of the engine Gas recirculation) and an engine controller for controlling the EGR are provided by the control means to determine whether the fuel density detected at a predetermined timing is within a predetermined range. Determined and achieved by controlling the EGR based on the determination result as to derive the decision signal to the engine controller.

  Hereinafter, the fuel management device for a construction machine according to the present invention will be described with reference to preferred embodiments.

  FIG. 1 is a diagram showing a schematic configuration of a fuel management system for executing a fuel management apparatus according to the present invention. In FIG. 1, the fuel management system includes a fuel discriminating device 1 mounted on a construction machine 20, an engine 8, peripheral equipment of the engine 8, a communication satellite 2, a base station 3, and a management center 4. Information from the determination device 1 is transmitted from the transmission device 19 to the management center 4 via the communication satellite 2 and the base station 3.

  The fuel discrimination device 1 includes a machine main body controller (second control means) 5, a detection means 6, a fuel controller (first control means) 14, a fuel level sensor 15, etc., and a machine main body controller (second control means) 5. The fuel controller (first control means) 14 and the fuel level sensor 15, the key switch unit 10 to which the start key 9 for starting the engine 8 of the construction machine 20 is mounted, and the engine for controlling the drive of the engine 8. A controller 11, a notification device 16 and a transmission device 19 are connected, and an engine speed sensor 18, a fuel injection device 22, and an EGR valve 23 are mounted on the engine 8, and the engine speed sensor 18, fuel injection device. 22, the EGR valve 23 and the switching valve 24 for switching the flow path of the exhaust gas include the engine controller 11. It is connected. An exhaust gas purifying device 25 is connected to the switching valve 24.

  The key switch unit 10 has a key hole (not shown) into which the start key 9 is inserted, and is moved from the “LOCK” position where the start key 9 can be inserted and removed to the “ON” position and the “START” position. A switchable key switch (not shown) is provided.

  The machine main body controller (second control means) 5 is composed mainly of a microcomputer, and determines whether or not the fuel identified by the fuel controller (first control means) 14 can be used. The fuel determination unit 5a serving as a control unit that outputs a control signal for managing the operation of the engine 20 and the fuel determination unit 5a is controlled so that the operation of the machine cannot be performed by stopping the engine or the like when the use determination is made The machine operation check means 17 which performs control is provided.

  Further, the machine main body controller (second control means) 5 is configured such that when the start key 9 is inserted into the key hole and the key switch is turned to the “ON” position, that is, when it is turned on, the fuel determination unit 5a Only when the fuel determination unit 5a permits the use of fuel, the engine start control is performed when the key switch is further rotated from the “ON” position to the “START” position. On the other hand, when the fuel determination unit 5a determines that the fuel is illegal, control is performed so that the engine does not start even if the key switch is rotated from the “ON” position to the “START” position. It also has a function of notifying 20 operators by text display or voice, and a function of notifying the management center 4 via the transmission device 19, the communication satellite 2 and the base station 3.

  The detection means 6 includes a fuel density sensor 12 and a temperature sensor 13. The density sensor 12 detects the density of the identified fuel and outputs a signal to the fuel controller (first control means) 14. The temperature sensor 13 detects the temperature of the identified fuel whose density is detected by the density sensor 12. To the fuel controller (first control means) 14. Based on the signal from the density sensor 12, the fuel controller (first control means) 14 identifies the type of fuel, such as whether the fuel used is light oil or other fuel, and identifies the machine body controller (first controller). (2 control means) 5 is output to the fuel judgment section 5a.

  The temperature measured by the temperature sensor 13 is the temperature-density at 15 ° C. obtained from the result measured by the density sensor 12 by the fuel-density conversion means 14 a provided in the fuel controller (first control means) 14. In other words, the type of fuel is identified as the fuel density at the time of conversion to 15 ° C., which makes it possible to accurately identify the fuel without being influenced by the fuel temperature (temperature environment).

Here, EGR that is mounted in the exhaust system of the engine 8, by returning to the engine 8 by mixing again the intake air portion of the once discharged gas, reduced to the NO _X lowers the combustion temperature Is. The return amount of the exhaust gas to the engine is adjusted by the EGR valve 23 or a solenoid under the control of the engine controller 11.

Exhaust gas which is not returned to the engine 8 in EGR is, DPF (Diesel Particulate Filter) and is passed through the exhaust gas purifying device 25, such as a NO _X catalyst is discharged to the outside, the switching valve 24 is switched by control of the engine controller 11 When it is, it is formed so that it is discharged outside without passing through the exhaust gas purification device 25.

  FIG. 2 is an explanatory diagram of the fuel tank 21. The fuel tank 21 includes a density sensor 12 that detects the density of the introduced fuel, a temperature sensor 13 that detects the temperature of the introduced fuel, A fuel level sensor 15 for detecting the fuel filling amount is provided, and the fuel-density conversion means 14a of the fuel controller (first control means) 14 determines the fuel based on the detection signal of the density sensor 12 and the detection signal of the temperature sensor 13. Is identified, and the identification information is output to the fuel determination section 5a of the machine main body controller (second control means) 5. Reference numeral 26 denotes a suction pipe for supplying the fuel in the fuel tank 21 to an injection pump (not shown).

  Then, the fuel density is detected by the density sensor 12 and, if necessary, the detected fuel density is out of the specified range with respect to the normal fuel density measured in advance while taking into account the fuel temperature detected by the temperature sensor 13. If it is, the machine main body controller (second control means) 5 issues an unusable determination signal.

  When the engine controller 11 receives this determination signal, it controls the EGR valve 23 to limit the return amount of the exhaust gas to the engine 8. Therefore, it is possible to prevent the deterioration and failure of the EGR component parts due to the use of unauthorized fuel.

  In addition, the engine controller 11 controls the fuel injection device 22 to limit the amount of fuel injected into the engine 8, thereby preventing deterioration or failure of engine components due to the use of unauthorized fuel.

  When the above-mentioned control is performed and the machine operation restraining means 17 of the machine main body controller (second control means) 5 receives the unusable determination signal, for example, the engine is stopped or the engine speed is forcibly reduced. Control may be performed so that the operation cannot be performed. Therefore, engine driving with non-permitted fuel cannot be continued, and problems such as failure of the engine 8 and generation of defective exhaust gas can be solved.

  FIG. 3 shows a fuel controller (first control means) 14 provided with a fuel judgment unit 14b for judging whether or not fuel can be used. In this case, the fuel discrimination device 1 includes a detection means 6 and a fuel controller (first control). Means) 14 and a fuel level sensor 15. The fuel determination unit 14b has the same function as the fuel determination unit 5a provided in the machine main body controller (second control unit) 5, and is detected by the density sensor 12 and the temperature sensor 13 of the detection unit 6. When information on the type of fuel is input to the fuel controller (first control means) 14 based on the density and temperature of the identified fuel, the fuel judgment unit 14b of the fuel controller (first control means) 14 can use the information. The determination signal is output to the machine body controller (second control means) 5.

  Based on the unusable determination signal output from the machine main body controller (second control means) 5 or the fuel controller (first control means) 14, data is transmitted to the base station 3 via the communication satellite 2, Alternatively, it may be configured to perform remote operations such as stopping the engine, lowering the engine speed, and inability to operate the machine.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

Explanatory drawing which shows schematic structure of the fuel management apparatus which concerns on this invention. Explanatory drawing of a fuel tank. Explanatory drawing which shows schematic structure of the other fuel management apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel discrimination apparatus 2 Communication satellite 3 Base station 4 Management center 5 Machine main body controller (2nd control means)
5a Fuel determination unit 6 Detection means 8 Engine 9 Key switch 10 Key switch unit 11 Engine controller 12 Density sensor 13 Temperature sensor 14 Fuel controller (first control means)
DESCRIPTION OF SYMBOLS 14a Fuel-density conversion means 14b Fuel determination part 15 Fuel level sensor 16 Notification apparatus 17 Machine operation check means 18 Engine speed sensor 19 Transmitter 20 Construction machine 21 Fuel tank 22 Fuel injection apparatus 23 EGR valve 24 Switching valve 25 Exhaust gas purification Equipment 26 Suction pipe

Claims (3)

In a construction machine fuel management device that determines whether or not a fuel used for an engine of the construction machine is mounted on the construction machine,
Detection means having a density sensor that outputs a signal corresponding to the density of fuel introduced into the fuel tank or fuel system of the construction machine, and whether the density of the identified fuel detected by the density sensor is within a predetermined range Is provided with a control means for determining whether or not the exhaust gas recirculation (EGR) for recirculating the exhaust gas of the engine and an engine controller for controlling the EGR, and whether the fuel density detected at a predetermined timing is within a predetermined range. A fuel management device for a construction machine, wherein the control means determines whether or not, derives the determination signal to the engine controller, and controls the EGR based on the determination result.   The detecting means has a temperature sensor for detecting the temperature of the identified fuel when the density sensor detects the density of the fuel, and whether the detected fuel density and fuel temperature are within a predetermined range. 2. The construction machine fuel management apparatus according to claim 1, wherein the control means determines whether or not the EGR is controlled based on the determination result.   3. The fuel management apparatus for a construction machine according to claim 1, wherein the engine controller controls a fuel injection amount to the engine based on a determination result instead of controlling the EGR.

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