Engine starting performance diagnostic device for construction machine

Abstract

Provided is an engine starting performance diagnostic device for a construction machine capable of easily and highly accurately diagnosing a state at the time of engine start in the construction machine. An engine start performance diagnostic device 2 of a construction machine 1 sets a rise timing of a starter signal of a starter 6, which imparts rotational force to an engine 3 when the engine start, as a startup point (0 point). Using data of the rotation speed of the engine, which is existing vehicle body data, the engine start performance diagnostic device 2 sets, as a threshold value, the rotation speed of the engine when a time taken to update from a certain rotation speed to a next rotation speed is less than a set time, extrapolates a line leading from the set threshold value to an autonomous operation rotation speed arrival point to a point set as an initial explosion rotation speed, and calculates two times: a first time (t1) from the startup point to the initial explosion rotation speed and a second time (t2) from the initial explosion rotation speed to the autonomous operation rotation speed arrival point. The engine start performance diagnostic device 2 then compares the calculated time with a preset reference value, and when the calculated time is larger than the reference value, diagnoses deterioration of each of the electric system components of the engine or deterioration of the components of the fuel supply system and fuel injection system.

Description

Construction machinery engine starting performance diagnostic device

[0001] The present invention relates to an engine starting performance diagnosis device for a construction machine.

[0002] Conventionally, various techniques relating to abnormality determination have been disclosed in the technical field of engine starting performance diagnosis devices for construction machinery that diagnose the starting performance of engines used in construction machinery. For example, as described in Patent Document 1, an engine starting performance diagnosis device is known that diagnoses abnormalities in electrical components such as the starter, battery, and alternator by calculating the operation duration for each operating state from when the power is turned on at engine start to when the engine starts, and from when the engine starts to when autonomous operation begins, as well as the average battery voltage within each operating state.

[0003] Patent No. 3816047

[0004] The above-mentioned engine starting performance diagnosis device for construction machinery determines the deterioration of electrical system components related to engine starting, such as the battery and starter, by the average value of battery voltage from the time the engine starts to rotate until the completion of autonomous operation. However, it is difficult to determine battery deterioration based solely on the transition of the average battery voltage, and because the total time until the engine achieves autonomous operation includes both electrical system components and fuel supply system / fuel injection system components, it is difficult to simply distinguish between abnormalities in the electrical system components and those in the fuel supply system / fuel injection system based solely on the battery voltage value.

[0005] In view of the above circumstances, the present invention aims to provide an engine starting performance diagnosis device for construction machinery that can easily diagnose engine starting performance and improve diagnostic accuracy by accurately diagnosing abnormalities in the engine's electrical system components and fuel supply system or fuel injection system components.

[0006] To solve the above problems, the present invention divides the period after engine startup for a construction machine into two periods: the period before the first combustion, when the engine speed increases due to the operation of electrical components, and the period from the first combustion, when the engine speed increases due to the power generated by fuel combustion, until the engine reaches self-sustaining operation. Each period is used for diagnosis. The threshold (time) that separates the periods before and after the first combustion at engine startup can be calculated by extrapolating a line connecting the engine speed at the time when the engine speed data update time falls below a set time and the self-sustaining operation speed to the engine speed set as the first combustion speed, thereby calculating the time from the first combustion speed to the self-sustaining operation speed. The time from the start point to the self-sustaining operation speed is calculated separately, and the difference between these is calculated as the time from the start point to the first combustion speed. This provides a construction machine engine starting performance diagnosis device that can accurately diagnose abnormalities in electrical components and fuel supply systems or fuel injection systems.

[0007] The construction machinery engine starting performance diagnosis device of the present invention is basically an engine starting performance diagnosis device for construction machinery that diagnoses the starting performance of an engine mechanically connected to a hydraulic pump built into the construction machinery, and is characterized by comprising: a calculation unit that calculates the time it takes for the engine speed to reach a predetermined threshold based on the engine speed measured by an engine speed sensor that measures the engine speed; and a diagnosis unit that diagnoses the engine starting performance by comparing the time calculated by the calculation unit with a predetermined reference value.

[0008] That is, one specific aspect of the construction machinery engine starting performance diagnosis device according to the present invention is a construction machinery engine starting performance diagnosis device that diagnoses the starting performance of an engine that is mechanically connected to a hydraulic pump incorporated in the construction machinery, and is characterized by comprising: a calculation device that sets the timing of the rising edge of a starter signal of a starter that applies rotational force to the engine when the engine is started as a starting point, sets the engine rotational speed when, from engine rotational speed data measured by a rotational speed sensor that measures the engine rotational speed, the time until updating from a certain rotational speed to the next rotational speed is less than a set time as a threshold value, and calculates a first time from the starting point to the first combustion rotational speed and a second time from the first combustion rotational speed to the self-sustaining operation rotational speed by extrapolating a line connecting the set threshold value and the point at which the engine rotational speed reaches the self-sustaining operation rotational speed to a point set as the first combustion rotational speed, and a diagnosis device that compares the first time or the second time calculated by the calculation device with a preset reference value based on the first time or the second time, and if it is greater than the reference value, diagnoses deterioration of the engine's electrical system components or the fuel supply system or the fuel injection system components, and outputs the diagnosis result.

[0009] According to the present invention, by accurately diagnosing abnormalities in the engine's electrical system components and fuel supply system or fuel injection system components, it is possible to easily diagnose the engine's starting performance and improve the diagnostic accuracy.

[0010] 5 is a schematic configuration diagram showing a construction machine equipped with a construction machine engine starting performance diagnosis device according to an embodiment. FIG. 5 is a configuration diagram showing a construction machine engine starting performance diagnosis device. FIG. 6 is a flowchart showing machine operation during data collection. FIG. 7 is a flowchart showing details of data collection in FIG. 3. FIG. 7 is an explanatory diagram of using a starter signal as a starting point. FIG. 8 is an explanatory diagram of how to determine a threshold value. FIG. 9 is an explanatory diagram of how to determine time t2. FIG. 10 is an explanatory diagram of how to determine time t1. FIG. 11 is a flowchart showing how to determine times t1 and t2. FIG. 12 is an explanatory diagram of how to determine points related to two straight lines for determining a threshold value using a method different from that of FIG. 6. FIG. 13 is an explanatory diagram of how to determine a threshold value using a method different from that of FIG. 6. FIG. 14 is an explanatory diagram of how to determine a starting point using battery voltage using a method different from that of FIG. 5. FIG. 15 is a flowchart showing details of data processing in FIG. 3. FIG. 16 is an explanatory diagram of an example of deterioration diagnosis of electrical system components during engine startability. FIG. 17 is an explanatory diagram of an example of deterioration diagnosis of fuel supply system and fuel injection system components during engine startability. FIG. 18 is an explanatory diagram of an example of deterioration diagnosis of electrical system components during engine startability.

[0011] An embodiment of a construction machine engine starting performance diagnosis device according to the present invention will be described below with reference to the drawings. The construction machine engine starting performance diagnosis device 2 according to this embodiment (hereinafter, sometimes simply referred to as the engine diagnosis device) is mounted on, for example, a construction machine 1 and is used to diagnose the starting performance of an engine 3 incorporated in the construction machine 1. While a construction machine will be used as an example, the present invention is applicable to other machines that operate using a hydraulic pump mechanically connected to the engine as a power source. The self-sustaining speed refers to an engine speed that is set in a range where the engine speed increases at the same rate before reaching the idle speed, and in this embodiment, this is 750 rpm. Setting the idle speed prevents accurate calculations in the event of overshooting or unstable behavior.

[0012] FIG. 1 is a schematic diagram showing a construction machine on which an engine diagnostic device for a construction machine according to an embodiment is mounted.

[0013] As shown in FIG. 1 , a construction machine 1 mainly includes an engine 3 and an engine diagnostic device 2 that diagnoses the starting performance of the engine 3. The engine diagnostic device 2 is equipped with a controller 10 and is equipped with various sensors (some of which are shown in the drawing, but will be described in detail later with reference to FIG. 2 ) for obtaining data necessary for controlling the vehicle body. The construction machine 1 is also equipped with a fuel pump 5 that supplies fuel to the engine 3, a starter 6 that operates when the engine 3 is started (to provide rotational force to the engine 3), a battery 4 that supplies power to the starter 6, and an alternator 7 that generates power to charge the battery 4 when the engine 3 is running. Furthermore, a hydraulic pump 8 is mechanically connected to an output shaft 9 of the engine 3 via a spline connection. The hydraulic pump 8 is, for example, a swash plate-type variable displacement hydraulic pump that changes its displacement depending on the tilt angle of its swash plate.

[0014] The battery 4, starter 6, and alternator 7 are components related to starting the engine 3 and constitute electrical system components of the engine 3. On the other hand, the fuel pump 5 is a component related to fuel supply and fuel injection to the engine 3 and constitutes fuel system components of the engine 3. In addition to the fuel pump 5, fuel system components include, for example, an injector and a fuel filter, although not shown.

[0015] FIG. 2 is a configuration diagram showing an engine diagnostic device for a construction machine.

[0016] The engine diagnostic device 2 includes a controller 10, to which a rotation speed sensor 22, a voltage sensor 23, a fuel flow rate sensor 24, a hydraulic oil temperature sensor 25, and a tilt angle sensor 26 are connected. The rotation speed sensor 22 measures the rotation speed of the engine 3 and outputs the measurement result to the controller 10. The rotation speed sensor 22 measures the rotation speed of the engine 3, for example, by detecting the number of teeth machined on a flywheel. The rotation speed sensor 22 is also driven by the battery 4 via the engine 3. The voltage sensor 23 measures the voltage of the battery 4 when the engine 3 is started and outputs the measurement result to the controller 10. The fuel flow rate sensor 24 measures the flow rate of fuel supplied to the engine 3 and outputs the measurement result to the controller 10. The hydraulic oil temperature sensor 25 measures the temperature of the hydraulic oil in the hydraulic pump 8 connected to the engine 3 and outputs the measurement result to the controller 10. The tilt angle sensor 26 measures the tilt angle of the swash plate that changes the displacement of the hydraulic pump 8 , and outputs the measurement result to the controller 10 .

[0017] The controller 10 is configured by a microcomputer that combines, for example, a CPU (Central Processing Unit) that executes calculations, a ROM (Read Only Memory) as a secondary storage device that records programs for the calculations, a RAM (Random Access Memory) as a temporary storage device that saves the calculation progress and temporary control variables, and a master clock that serves as a basis for measuring the CPU's calculation cycle and time, and controls each component of the construction machine 1, including the engine 3, by executing the stored programs.

[0018] The controller 10 includes a calculation device 211, a diagnostic device 212, and a storage device 213. The calculation device 211 performs various calculations related to control. For example, the calculation device 211 calculates the time required for the engine speed to reach a preset threshold based on engine speed data measured by the speed sensor 22. The diagnostic device 212 performs various diagnoses related to control. For example, the diagnostic device 212 diagnoses the engine starting performance by comparing the results of calculations performed by the calculation device 211 with preset reference values. The storage device 213 temporarily stores the calculated data and the like.

[0019] The engine diagnostic device 2 of this embodiment is equipped with a monitor 27, which is attached, for example, to the cab of the construction machine 1. The monitor 27 displays the output contents from the diagnostic device 212, and an operator or worker working can check the diagnostic results and the status via the monitor 27.

[0020] 3, the operation procedure of the machine for collecting data at engine start-up, which is related to the starting performance diagnosis of the engine 3, will be described. The data collected here is mainly data on the engine speed, key position signal, engine status signal, starter signal, hydraulic oil temperature, and tilt angle.

[0021] First, the key to the engine 3 is turned on (see step S301). Next, the controller 10 determines whether the key position signal and the engine state signal are at preset thresholds (see step S302). The key position signal is displayed, for example, as an integer from 0 to 3, with 0 indicating "OFF," 1 indicating "accessory state," 2 indicating "ON state," and 3 indicating "start (cranking) state." The engine state signal is displayed, for example, as an integer from 0 to 1, with 0 indicating "stopped state" and 1 indicating "engine running state." The thresholds are set, for example, as "2" for the key position signal, which turns ON, and "0" for the engine state signal.

[0022] If it is determined that the signal does not match the threshold (see NO in step S302), it is determined that the engine is not running, and the determination in step S302 is repeated. On the other hand, if it is determined that the key position signal and the engine state signal match the threshold (see YES in step S302), power is supplied from the battery 4 to the rotation speed sensor 22. That is, power is supplied to the rotation speed sensor 22, voltage sensor 23, fuel flow rate sensor 24, hydraulic oil temperature sensor 25, tilt angle sensor 26, and monitor 27 (see step S303). At the same time, data collection in the storage device 213 is started (see step S304), and then the engine is started, and a series of sensor data is collected from before the engine starts until it reaches idle rotation speed.

[0023] In step S305 following step S304, the collected data is processed using a series of processes described below. The processed data is then used to evaluate the data in step S306. After data evaluation in step S306 is completed, the engine stop sequence is started in the following steps S307 and onward. Details of steps S304 to S306 will be described later.

[0024] In step S307 following step S306, it is determined whether the idle speed has continued for a predetermined time. In this embodiment, the determination condition is whether a predetermined time, for example, 30 seconds, has elapsed since the idle speed was reached. This is to confirm whether data at engine start-up has been collected. It is sufficient that data at engine start-up, such as engine speed, starter signal, battery voltage signal, hydraulic oil temperature, and tilt angle, which are used for determination, have been collected, and the time is not limited to 30 seconds and may be changed as appropriate depending on the actual situation, etc.

[0025] If it is determined that 30 seconds have not elapsed since the engine speed reached the idle speed, the determination process of step S307 is repeated until 30 seconds have elapsed since the engine speed reached the idle speed. On the other hand, if it is determined that 30 seconds have elapsed since the engine speed reached the idle speed, it is determined whether or not to continue the work in order to stop the engine (see step S308).

[0026] In step S308 following step S307, the diagnosis device 212 determines whether or not to continue the work. One method of determination is to detect an increase in engine speed from idle speed to a steady speed during work, but during work, the tilt angle of the hydraulic pump is increased to increase the amount of hydraulic oil supplied from the hydraulic pump 8 to the traveling hydraulic motor (not shown) and the front device hydraulic cylinder, and therefore the change in tilt angle at this time can be measured using the tilt angle sensor 26 to determine whether or not to continue the work, but the method is not limited to this.

[0027] If it is determined that the work will continue, the determination is repeated again. On the other hand, if it is determined that the work will not continue, the process exits from the determination loop of step S308, and the rotation speed of the engine 3 is reduced to idle rotation (see step S309). Thereafter, the engine is stopped (see step S310). This ends the operation of the machine for data collection at engine start.

[0028] Referring to FIG. 4, details of the data collection procedure at engine start related to the engine starting performance diagnosis of the engine 3 in the engine starting performance diagnosis procedure by the engine diagnosis device 2 for construction machinery, the overall outline of which is explained in FIG. 3, will be described.

[0029] First, an initial value n=0 is set for a parameter n for counting data (see step S401). At the same time, counting is started at a predetermined cycle based on a master clock built into the microcomputer (see step S402). Synchronously with the counting, 1 is added to the data count parameter each time measurement data is measured by the fuel flow sensor 24, hydraulic oil temperature sensor 25, and tilt angle sensor 26 (see step S403). These calculated values ​​are grouped together with the data count parameter n and stored in the storage device 213 (see step S404).

[0030] Next, it is determined whether the engine is running based on the engine speed data (see step S405). If the engine speed data is greater than 0 (see YES determination in step S405), it is determined that the engine is running, and the process proceeds to step S409. On the other hand, if the engine speed data is 0 (see NO determination in step S405), it is determined that the engine is not running, and the engine is started (see step S406). At this time, the key position signal changes from "3" to "2," and the engine state signal is "1." By receiving these signals, the controller 10 detects that the engine 3 has started.

[0031] The fuel consumed by the engine is measured by the fuel flow sensor 24 (see step S407), and it is determined whether fuel is flowing (see step S408). If it is determined that the fuel flow rate is zero (see NO in step S408), the process returns to step S403, and the fuel flow rate data is retrieved again. On the other hand, if it is determined that the fuel flow rate is greater than zero (see YES in step S408), the engine speed data is retrieved (see step S409), and the retrieved engine speed is set as the initial combustion speed f(x) (see step S410).

[0032] In step S411, it is determined whether the current engine speed f(n) has reached the initial combustion speed f(x). This determination process is repeated until it is determined that the current engine speed f(n) is greater than the initial combustion speed f(x). If it is determined that the current engine speed f(n) is greater than the initial combustion speed f(x) (see YES in step S411), the process proceeds to the next step S412.

[0033] Next, for the retrieved engine speed data, it is determined whether the current engine speed data f(n) is equal to or less than the immediately preceding engine speed data f(n-1) (see step S412). If it is determined that the current engine speed f(n) is greater than the immediately preceding data f(n-1) (see NO at step S412), it is determined that the current engine speed f(n) has not yet reached the idle speed, and the process returns to step S409, where the engine speed data is retrieved again. If it is determined that the current engine speed data f(n) is equal to or less than the immediately preceding data f(n-1) (see YES at step S412), it is determined that the idle speed has been reached.

[0034] In step S412, if it is determined that the current engine speed f(n) has reached the idle speed (see step S412, YES), data for subsequent engine speeds f(n+1) and onward is deleted (see step S413), and the process proceeds to step S414. In step S414, the data obtained up until engine speed f(n) is reached is stored in storage device 213, and data processing is performed.

[0035] Figure 5 shows an explanatory diagram of using the starter signal as the starting point. In Figure 5, black and white circles represent engine speed data, and diamonds represent starter signals. Note that the engine speed and starter signal were measured simultaneously.

[0036] As shown in FIG. 5, the timing at which the starter signal changes from 0 to 1 coincides with the starting point (point 0) of the engine speed. Therefore, in this embodiment, the changing point (rising timing) of the starter signal is used as the starting point (point 0) for diagnosis.

[0037] Fig. 6 shows an explanatory diagram of how the thresholds are determined. In Fig. 6, the open circles represent engine speed data, and the closed circles represent starter signals. In this embodiment, the update time for the engine speed data represented by the open circles is set to 0.02 seconds.

[0038] The update time for engine speed data tends to be long in the low speed range (the same engine speed data continues for a long time) and short in the high speed range. By setting the point at which the increase rate of engine speed data becomes constant as the threshold and calculating the time by extrapolating to the first combustion speed, the variation is reduced compared to calculating the time from the engine speed data directly to the first combustion speed. Therefore, in this embodiment, the engine speed at which the update time is less than 0.1 seconds is set as the threshold. That is, in this embodiment, the engine speed data, which is existing vehicle data, is used, and the engine speed at which the time from one rotation speed to the next rotation speed becomes less than the set time (less than 0.1 seconds) is set as the threshold.

[0039] FIG. 7 shows an explanatory diagram of how to determine the engine start time t2.

[0040] First, a line is calculated connecting the threshold value shown in FIG. 6 and the rotation speed set as the autonomous operation rotation speed (750 rpm in this embodiment). In this embodiment, if there are multiple data points at the same rotation speed, the two central data points are used, but the first point or the last point (the point immediately before a new value is taken) may also be used, and there is no limitation. Next, the line is extrapolated to the first explosion rotation speed extracted from the behavior of the fuel flow data, and the time at that point is calculated. Furthermore, the time from the time of the first explosion rotation speed to the time when the autonomous operation rotation speed (750 rpm) is reached is calculated and set as t2.

[0041] A method for determining the time t1 after determining the engine start time t2 will be described with reference to FIG.

[0042] The time when the starter signal rises (when the value changes from 0 to 1) is set as the starting point (point 0), and the time until the autonomous operation rotation speed (750 rpm) is reached is calculated as tall, and the difference (tall - t2) from t2 shown in the explanation of Figure 7 is calculated as t1. That is, in this embodiment, the line connecting the threshold value and the autonomous operation rotation speed reached point shown in Figure 6 is extrapolated to the point set as the initial explosion rotation speed, thereby calculating two types of time: a first time (t1) from the starting point (point 0) to the initial explosion rotation speed, and a second time (t2) from the initial explosion rotation speed to the autonomous operation rotation speed being reached.

[0043] 9 shows a flowchart for determining the times t1 and t2. The processing shown in FIG.

[0044] First, data stored in the storage device 213, including engine speed data and starter signal data, are called from the storage device 213 (see step S901). Next, it is determined whether the starter signal is 0 or 1 (see step S902).

[0045] If the starter signal is 1 (see step S902, YES), the time information at that time is stored in the storage device 213 (see step S903). On the other hand, if the starter signal is 0 (see step S902, NO), it is determined that the engine has not yet started, and the process from data call in step S901 is repeated until the starter signal becomes 1. Furthermore, the time stored in the storage device 213 is set as the time of the start point (point 0) (see step S904).

[0046] Thereafter, the update time of the engine rotation speed data is checked (see step S905). In this embodiment, if the update time, i.e., the time during which the same value continues, is less than 0.1 seconds (see step S905, YES determination), that value is set as a threshold value and stored in the storage device 213 (see step S906). On the other hand, if the update time is 0.1 seconds or more (see step S905, NO determination), the process is repeated from step S901, starting with the data call.

[0047] Next, a straight line is calculated connecting the calculated threshold value and the autonomous operation rotation speed (750 rpm in this embodiment) (see step S907). Furthermore, the time at which the set first explosion rotation speed is reached is obtained by extrapolation using the straight line (see step S908), and the engine rotation speed and time information are stored in the storage device 213 (see step S909).

[0048] Then, t2, which is the time required from the initial combustion rotation speed to the self-sustaining operation rotation speed (750 rpm), is calculated (see step S910) and stored in the storage device 213 (see step S911). Furthermore, the time (tall) from the rising point (starting point) of the starter signal to the self-sustaining operation rotation speed (750 rpm) is calculated (see step S912), and the difference between tall and t2 is calculated to obtain t1, which is the time required from the rising point (starting point) of the starter signal to the self-sustaining operation rotation speed (750 rpm) (see step S913). Finally, the calculated t1 and t2 are stored in the storage device 213 (see step S914), and the process ends.

[0049] FIG. 10 is an explanatory diagram showing how to select points related to two straight lines to determine a threshold value using a method different from the method shown in FIG.

[0050] The white circle in Figure 10 indicates the behavior of the engine speed data from the start point (point 0) until the autonomous operation speed is reached. The four points constituting the two straight lines are indicated by arrows in the figure. The four points are the two closest points p1 and p2 below 750 rpm set as the autonomous operation speed (i.e., point p1 below the autonomous operation speed and closest to the autonomous operation speed, and point p2 next closest to the autonomous operation speed, different from point p1), and two points p3 and p4 where the engine speed rises from 0 (i.e., point p3, the first point other than 0 obtained after the engine speed reaches 0, and point p4, the next point where the engine speed differs from point p3). Each of the two points has a different value (engine speed). This is based on the fact that the rate of increase in engine speed is different between the start of cranking and the initial combustion speed, and from the initial combustion speed to the self-sustaining operation speed. The purpose is to find the transition position (threshold value) by extracting two points in each region and drawing an approximate line between the two points in each region.

[0051] FIG. 11 is an explanatory diagram showing a method of determining a threshold value using a method different from the method shown in FIG.

[0052] This method uses the points extracted in FIG. 10 to draw two straight lines as shown in the figure, and sets the intersection (the engine speed corresponding to the intersection) as the threshold value. Subsequent processing is performed using the method described in the flowchart of FIG. 9. That is, using the threshold value calculated above, the time at which the first combustion speed determined based on the fuel flow data is reached is first obtained by extrapolation using a straight line connecting the threshold value and the autonomous operation speed (750 rpm). Furthermore, t2 and tall are calculated in order, and then t1 is obtained.

[0053] FIG. 12 is a diagram illustrating a method for determining the starting point based on the battery voltage, which is different from the method shown in FIG.

[0054] In the above embodiment, the starting point (point 0) is set as the timing for updating the starter signal data, but the timing of the drop in battery voltage when the engine is started can also be used instead. Furthermore, by using the battery voltage, not only can the above timing be extracted, but also the time it takes for the voltage to return to normal can be monitored, and if it is longer than normal, it can be determined that there is a sign of deterioration. Similarly, if the amount of drop in battery voltage is larger than normal, it can be determined that there is a sign of deterioration.

[0055] FIG. 13 shows a detailed flowchart of data processing in this embodiment.

[0056] First, parameter N is set and 0 is input (see step S1301). Next, parameter P is set and 0 is input (see step S1302). Next, data is retrieved from the storage device 213 (see step S1303), and the hydraulic oil temperature is determined (see step S1304) to eliminate external factors other than engine component problems. This is to eliminate the effect of drag caused by oil hardness during cold start-up. In other words, this determination determines that the data (t1, t2) satisfy the hydraulic oil temperature condition where the effect of drag is negligible, and the valid data is used. If the hydraulic oil temperature is 30°C or higher (see step S1304, YES), it is determined that the effect of drag is negligible, and the process proceeds to step S1305. On the other hand, if the hydraulic oil temperature is less than 30°C (see step S1304, NO), the process is repeated from step S1303 until the hydraulic oil temperature reaches 30°C or higher.

[0057] Next, it is determined whether t1 and t2 are within a set range (see step S1305). The ranges to be evaluated are set for α and β in FIG. 13. For example, 0.2 sec is entered for α and 5.0 sec for β, and data within that range is considered valid data. First, if t1 and t2 are within the set range (see step S1305, YES), the process proceeds to step S1309. On the other hand, if t1 and t2 are not within the set range (see step S1305, NO), the process proceeds to step S1306. If t1 and t2 are not within the set range, 1 is added to P (see step S1306), and it is further determined whether P is 3 (see step S1307).

[0058] If P=3 (YES at step S1307), it is further determined whether the occurrence occurred three times consecutively (step S1308). If P is not 3 (NO at step S1307), the process returns to step S1303, where the data is retrieved.

[0059] If P=3 and has occurred three times in a row, proceed to step S1309. On the other hand, if P=3 but has not occurred three times in a row, return to step S1302 and repeat the process. If P=3 and has occurred three times in a row, add 1 to N (see step S1309). In this embodiment, the threshold value for P is set to 3, but this is not limiting.

[0060] Furthermore, it is determined whether N is 9 or greater (see step S1310). If N is 9 or greater (see YES determination at step S1310), the data is stored in the storage device 213 (see step S1311). Thereafter, the data is called up, and median processing of the nine data for each of t1 and t2 is performed (see step S1312), followed by average processing (see step S1313). The calculated results are stored in the storage device 213 as feature amounts (see step S1314), and the process ends.

[0061] 14 to 17 show examples of deterioration diagnosis using the feature amounts calculated in Fig. 13. The processes shown in Fig. 14 to 17 are performed by the diagnosis device 212.

[0062] 14 and 15 show a case where a calculated feature value is greater than a threshold value (reference value) for five consecutive times, and a diagnosis of deterioration is made, with Fig. 14 showing an example of diagnosing t1 and Fig. 15 showing an example of diagnosing t2. Fig. 16 and 17 show a case where a calculated feature value is greater than a threshold value (reference value) for five consecutive times, and the value increases for five consecutive times, and a diagnosis of deterioration is made, with Fig. 16 showing an example of diagnosing t1 and Fig. 17 showing an example of diagnosing t2.

[0063] First, an example of a case where a calculated feature amount t1 exceeds a threshold value (reference value) five times in succession is diagnosed as degradation will be described with reference to FIG.

[0064] First, a parameter n is set and 0 is input (see step S1401). Next, 1 is added to n (see step S1402). The feature amount data t1 calculated in FIG. 13 is called (see step S1403), and it is determined whether the threshold value γ is reached (see step S1404). The threshold value γ can be set arbitrarily in advance.

[0065] If the threshold value γ is reached (YES at step S1404), the process proceeds to step S1405. On the other hand, if the threshold value γ is not reached (NO at step S1404), the process returns to step S1401 and is repeated.

[0066] Next, it is determined whether n has been output a set number of times in succession (see step S1405). In this embodiment, it is set to 5 times, but this is not limiting. If n is 5 or more (see step S1405, YES determination), it is further diagnosed whether those 5 times have been output in succession (see step S1406). On the other hand, if n is not 5 or more (see step S1405, NO determination), the process returns to step S1402 and is repeated.

[0067] If the threshold exceedance is output five or more times in a row (see step S1406, YES), it is determined that the diagnosis is for deterioration of the engine's electrical system components (see step S1407). On the other hand, if the threshold exceedance is not output five or more times in a row (see step S1406, NO), the process returns to step S1402 and is repeated. If the threshold exceedance is output five or more times in a row (see step S1406, YES), the administrator is notified by displaying it on the monitor 27 (see step S1408), and the determination ends.

[0068] Next, an example of a case where the calculated feature amount t2 exceeds the threshold value (reference value) five times in succession will be described with reference to FIG. 15 .

[0069] First, a parameter n is set and 0 is input (see step S1501). Next, 1 is added to n (see step S1502). The feature amount data t2 calculated in FIG. 13 is called (see step S1503), and it is determined whether the threshold value ε is reached (see step S1504). The threshold value ε can be set arbitrarily in advance.

[0070] If the threshold value ε is reached (YES at step S1504), the process proceeds to step S1505. On the other hand, if the threshold value ε is not reached (NO at step S1504), the process returns to step S1501 and is repeated.

[0071] Next, it is determined whether n has been output a set number of times in succession (see step S1505). In this embodiment, it is set to 5 times, but this is not limiting. If n is 5 or more (see step S1505, YES determination), it is further diagnosed whether those 5 times have been output in succession (see step S1506). On the other hand, if n is not 5 or more (see step S1505, NO determination), the process returns to step S1502 and is repeated.

[0072] If the threshold exceedance is output five or more times in a row (see step S1506, YES), it is determined that the engine fuel supply system / fuel injection system components have been diagnosed for deterioration (see step S1507). On the other hand, if the threshold exceedance is not output five or more times in a row (see step S1506, NO), the process returns to step S1502 and is repeated. If the threshold exceedance is output five or more times in a row (see step S1506, YES), the administrator is notified by displaying it on the monitor 27 (see step S1508), and the determination ends.

[0073] If the feature value of t1 indicates deterioration, it is determined that the electrical components such as the starter, battery, and alternator are not normal and have deteriorated, since this is the time before the first fuel explosion. Also, if the feature value of t2 indicates deterioration, it is determined that the fuel supply system components and fuel injection system components such as the fuel pump, injector, and fuel filter are not normal and have deteriorated, since this is the time when the engine speed increases due to the fuel explosion. This is also true for the following Figures 16 and 17.

[0074] Next, with reference to FIG. 16, an example of a case where the calculated feature value t1 exceeds the threshold value (reference value) five times in succession and the value also increases continuously will be described, in which the deterioration is diagnosed.

[0075] First, a parameter n is set and 0 is input (see step S1601). Next, 1 is added to n (see step S1602). The feature amount data t1 calculated in FIG. 13 is called (see step S1603), and it is determined whether or not the threshold value γ is reached (see step S1604). Note that the threshold value γ can be arbitrarily set in advance, as in the case of FIG. 14.

[0076] If the threshold value γ is reached (YES at step S1604), the process proceeds to step S1605. On the other hand, if the threshold value γ is not reached (NO at step S1604), the process returns to step S1601 and is repeated.

[0077] If it is determined in step S1604 that the threshold value γ has been reached (see step S1604, YES), a determination is made as to whether the value has increased from the previous value (see step S1605). If the value has increased compared to the previous value (see step S1605, YES), the process proceeds to step S1606. On the other hand, if the value has not increased compared to the previous value (see step S1605, NO), the process returns to step S1601 and is repeated.

[0078] If it is determined that the value has increased compared to the previous value (see step S1605, YES), it is determined whether the value has exceeded the threshold value γ and increased compared to the previous value five times in a row (see step S1606). If it is determined that the value has been output five times in a row (see step S1606, YES), the process proceeds to the next step S1607. On the other hand, if it is determined that the value has not been output five times in a row (see step S1606, NO), the process returns to step S1602 and is repeated.

[0079] If it is determined in step S1606 above that the signal has been output five times in succession (see step S1606, YES determination), it is determined that the engine's electrical components have deteriorated (see step S1607), and the administrator is notified of this fact, for example by displaying it on the monitor 27 (see step S1608), and the determination ends.

[0080] Next, with reference to FIG. 17, an example of diagnosing deterioration when the calculated feature value t2 exceeds the threshold value (reference value) five times in succession and the value is also increasing continuously will be described.

[0081] First, a parameter n is set and 0 is input (see step S1701). Next, 1 is added to n (see step S1702). The feature amount data t2 calculated in FIG. 13 is called (see step S1703), and it is determined whether the threshold value ε is reached (see step S1704). Note that the threshold value ε can be arbitrarily set in advance, as in the case of FIG. 15.

[0082] If the threshold value ε is reached (YES at step S1704), the process proceeds to step S1705. On the other hand, if the threshold value ε is not reached (NO at step S1704), the process returns to step S1701 and is repeated.

[0083] If it is determined in step S1704 that the threshold value ε has been reached (see step S1704, YES), a determination is made as to whether the value has increased from the previous value (see step S1705). If the value has increased compared to the previous value (see step S1705, YES), the process proceeds to step S1706. On the other hand, if the value has not increased compared to the previous value (see step S1705, NO), the process returns to step S1701 and is repeated.

[0084] If it is determined that the value has increased compared to the previous value (see step S1705, YES), it is determined whether the value has exceeded the threshold value ε and increased compared to the previous value five times in a row (see step S1706). If it is determined that the value has been output five times in a row (see step S1706, YES), the process proceeds to the next step S1707. On the other hand, if it is determined that the value has not been output five times in a row (see step S1706, NO), the process returns to step S1702 and is repeated.

[0085] If it is determined in step S1706 above that the signal has been output five times in succession (see step S1706, YES determination), it is determined that the engine's fuel supply system and fuel injection system components have deteriorated (see step S1707), and the administrator is notified of this fact, for example by displaying it on the monitor 27 (see step S1708), and the determination ends.

[0086] As for the method of notifying the manager, for example, information is sent to a monitor in the cab or to the machine control room, and the operator, operations manager, machine manager, etc. are notified that the engine startability is deteriorating. Note that the notification means may include a monitor display, a buzzer, or a lit lamp, but is not limited to this as long as the operator, operations manager, or machine manager is aware of the deterioration notification. Furthermore, in addition to notifying the manager (deterioration notification), control may be implemented to stop the engine and stop operation of the construction machine 1 in the case of a deterioration diagnosis. The engine starting performance diagnosis device 2 for the construction machine 1 according to this embodiment can be commonly applied to all models, regardless of the engine model or installed model.

[0087] As explained above, the engine starting performance diagnosis device 2 for a construction machine 1 according to this embodiment is an engine starting performance diagnosis device 2 for a construction machine 1 that diagnoses the starting performance of the engine 3 that is mechanically connected to the hydraulic pump 8 incorporated in the construction machine 1, and sets the timing of the rise of the starter signal of the starter 6 that applies rotational force to the engine 3 when the engine is started as the starting point (point 0), and sets the engine rotation speed when the time from one rotation speed to the next rotation speed becomes less than a set time from the engine rotation speed data measured by the rotation speed sensor 22 that measures the engine rotation speed as the threshold value, The system is equipped with a calculation device 211 that calculates a first time (t1) from the starting point to the first explosion rotation speed and a second time (t2) from the first explosion rotation speed to the self-sustaining operation rotation speed by extrapolating a line connecting a set threshold value and the point at which the engine rotation speed reaches the self-sustaining operation rotation speed to the point set as the first explosion rotation speed, and a diagnostic device 212 that compares the first time (t1) or the second time (t2) calculated by the calculation device 211 with a predetermined reference value, and if the first time (t1) or the second time (t2) calculated by the calculation device 211 is greater than the reference value, diagnoses deterioration of the engine's electrical system components or fuel supply system or fuel injection system components, respectively, and outputs the diagnosis result.

[0088] The calculation device 211 sets the threshold value to the engine speed corresponding to the intersection of a line formed by two points: the first point (p3) other than 0 obtained after the engine speed is 0, and the next point (p4) obtained where the engine speed is different from the first point (p3), and a line formed by two points: the point (p1) closest to the autonomous operating speed that is less than the autonomous operating speed, and the point (p2) next closest to the autonomous operating speed where the engine speed is different from the closest point (p1) (Figures 10 and 11).

[0089] The arithmetic unit 211 estimates the starting point based on the battery voltage of the battery 4 that supplies power to the starter 6 (FIG. 12).

[0090] The diagnostic device 212 uses, as valid data, data (the calculation results of the calculation device 211) that meets the conditions of the hydraulic oil temperature where the influence of drag can be ignored.

[0091] The diagnostic device 212 compares the first time (t1) with a predetermined reference value (γ), and if the first time (t1) is greater than the reference value (γ), it diagnoses that the engine's electrical components (battery, starter, alternator, etc.) are not normal.

[0092] The diagnostic device 212 compares the second time (t2) with a preset reference value (ε), and if the second time (t2) is greater than the reference value (ε), it diagnoses that the engine's fuel supply system or fuel injection system components (fuel pump, injector, fuel filter, etc.) are not normal.

[0093] In addition, the engine starting performance diagnosis device 2 of the construction machine 1 displays (and notifies) the diagnosis results output from the diagnosis device 212 on the monitor 27, or performs control to stop the engine 3 if the diagnosis results output from the diagnosis device 212 indicate deterioration.

[0094] According to this embodiment, by accurately diagnosing abnormalities in the engine's electrical components and fuel supply system or fuel injection system components, it is possible to easily diagnose the engine's starting performance and improve diagnostic accuracy.

[0095] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as set forth in the claims.

[0096] REFERENCE SIGNS LIST 1 Construction machine 2 Engine starting performance diagnostic device 3 Engine 4 Battery 5 Fuel pump 6 Starter 7 Alternator 8 Hydraulic pump 9 Output shaft 10 Controller 22 Revolution speed sensor 23 Voltage sensor 24 Fuel flow rate sensor 25 Hydraulic oil temperature sensor 26 Tilt angle sensor 27 Monitor 211 Arithmetic unit 212 Diagnostic device 213 Storage device

Claims

1. A construction machinery engine starting performance diagnosis device that diagnoses the starting performance of an engine mechanically connected to a hydraulic pump built into the construction machinery, comprising: a calculation device that sets the timing of the rising edge of a starter signal of a starter that provides rotational force to the engine when the engine is started as a starting point, sets the engine speed when the time it takes to update from a certain speed to the next speed becomes less than a set time from engine speed data measured by a speed sensor that measures engine speed as a threshold value, and calculates a first time from the starting point to the first explosion speed and a second time from the first explosion speed to the autonomous operation speed by extrapolating a line connecting the set threshold value and the point at which the engine speed reaches the autonomous operation speed to a point set as the first explosion speed; and a diagnosis device that compares the first time or the second time calculated by the calculation device with a preset reference value based on the first time or the second time calculated by the calculation device, and if it is greater than the reference value, diagnoses deterioration of the engine's electrical system components, or the fuel supply system or the fuel injection system components, and outputs the diagnosis result.

2. In the engine starting performance diagnosis device for construction machinery described in claim 1, the calculation device sets as the threshold value the engine speed corresponding to the intersection of a line formed by two points: the first point other than 0 when the engine speed is 0, and the next point obtained where the engine speed is different from the first point, and a line formed by two points: a point that is less than the autonomous operating speed but is closest to the autonomous operating speed, and a point where the engine speed is next closest to the autonomous operating speed but is different from the closest point.

3. An engine starting performance diagnosis device for a construction machine as claimed in claim 1, characterized in that the arithmetic unit estimates the starting point based on the battery voltage of a battery that supplies power to the starter.

4. An engine starting performance diagnosis device for a construction machine as described in claim 1, characterized in that the diagnosis device uses as valid data data that meets the hydraulic oil temperature conditions where the effect of drag can be ignored.

5. The engine starting performance diagnosis device for construction machinery according to claim 1, characterized in that the diagnosis device compares the first time with a preset reference value and, if it is greater than the reference value, diagnoses that the engine's electrical system components are not normal.

6. An engine starting performance diagnosis device for construction machinery as described in claim 1, characterized in that the diagnosis device compares the second time with a preset reference value and, if it is greater than the reference value, diagnoses that the engine's fuel supply system or fuel injection system components are not normal.

7. An engine starting performance diagnosis device for a construction machine as described in claim 1, characterized in that the diagnosis results output from the diagnosis device are displayed on a monitor, or control is implemented to stop the engine if the diagnosis results output from the diagnosis device indicate deterioration.

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