Diagnostic device for diagnosing deterioration of engine starting performance in construction machinery

Abstract

The present invention provides a diagnostic device for the deterioration of engine starting performance in construction machinery, which enables easy and highly accurate diagnosis of the quality of engine starting performance, i.e., deterioration. [Solution] The starting point is the timing when the battery current value reaches its maximum value during engine startup. Furthermore, the timing when the engine fuel flow rate shows a value other than zero is set as the initial combustion speed. The time from engine startup to reaching the initial combustion speed and the time from the initial combustion speed to reaching the self-sustaining operation speed are calculated. If this time, when viewed in a time series, exceeds a preset threshold based on the time of normal engine startup and is continuously increasing, it is diagnosed that the engine's starting performance has deteriorated. Furthermore, deterioration of electrical components is identified by diagnosis based on the current value level measured during engine startup. In addition, deterioration of fuel supply system components or fuel injection system components is identified by diagnosis based on the rotational speed that rises with a fixed fuel flow rate of the engine.

Description

Technical Field

[0001] The present invention relates to an engine starting performance deterioration diagnosis device for determining deterioration in the starting performance of an engine used in a construction machine having a structure in which an engine is directly connected to a hydraulic pump.

Background Art

[0002] Conventionally, in such a technical field, techniques related to various abnormality determinations have been disclosed. For example, as described in Patent Document 1, by calculating the operation continuation time for each operation state from power-on at engine start to engine start and from engine start to independent operation start, and the average battery voltage within the time for each operation state, an abnormality detection device for an internal combustion engine starting system that diagnoses abnormalities in electrical system components such as a starter, battery, and alternator is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above-mentioned abnormality detection device for an internal combustion engine starting system determines deterioration of electrical system components related to engine starting, such as a battery and a starter, based on the average value of the battery voltage from the start of engine rotation to the attainment of the independent operation rotational speed. However, it is difficult to determine battery deterioration solely based on the transition of the average value of the battery voltage. Also, since the total time until the engine reaches the independent operation rotational speed includes two elements, an electrical system element and a fuel system element, it is difficult to simply distinguish between deterioration of electrical system components and fuel system components based only on the battery voltage value.

[0005] In view of the above circumstances, the present invention aims to provide a diagnostic device for diagnosing deterioration of engine starting performance in construction machinery, which enables easy and highly accurate diagnosis of the quality of engine starting performance, i.e., deterioration. [Means for solving the problem]

[0006] To solve the above problems, the present invention divides the engine used in construction machinery into two periods: the period before the initial combustion when the engine speed increases due to the operation of electrical components after engine startup, and the period from the initial combustion when the engine speed increases due to the power generated by the combustion of fuel until the engine reaches its self-sustaining operating speed. The present invention then performs deterioration diagnosis of engine components during each of these periods.

[0007] Specifically, the system defines the starting point as the moment when the battery current reaches its maximum value during engine startup, and the initial combustion speed as the moment when the engine's fuel flow rate shows a value other than zero. By calculating the time from engine startup to reaching the initial combustion speed and the time from the initial combustion speed to reaching the self-sustaining operating speed, the system diagnoses that the engine's starting performance has deteriorated if, when viewed over time, this time exceeds a predetermined threshold based on the time required for normal engine startup and is continuously increasing.

[0008] Furthermore, the device identifies deteriorated electrical components by comparing the current level at engine startup with a preset threshold based on the current level during normal engine startup, and classifying cases into those that do not exceed the threshold and those that do. It also identifies deteriorated fuel system components by comparing the rotational speed level at which the engine speed increases with a fixed fuel flow rate with the rotational speed at which the engine speed increases with a fixed fuel flow rate during normal engine startup, and classifying cases into those that are above the threshold and those that are below it. This provides a diagnostic device for diagnosing deterioration of engine starting performance in construction machinery, enabling accurate diagnosis of abnormalities or deterioration in electrical components, fuel injection, or fuel supply system components, and allowing for the identification of the most deteriorated electrical components, fuel system components, and other components.

[0009] In other words, a specific embodiment of the present invention is a diagnostic device for the deterioration of engine starting performance of a construction machine, comprising: an engine tachometer for measuring the rotational speed of the engine; an ammeter for measuring the current of a battery that supplies power to a starter that operates when the engine is started; and a fuel flow meter for measuring the fuel flow rate of the engine, wherein the timing at which the battery current value shows its maximum value when the engine is started is set as the starting point, and the timing at which the engine fuel flow rate shows a value other than 0 is set as the initial combustion speed, and a calculation device for calculating the time from when the engine is started until the initial combustion speed is reached, and the time from the initial combustion speed until the self-sustaining operation speed is reached, and the calculation device The diagnostic device is characterized by comprising: a diagnostic device that, when viewed in a time series, diagnoses that the engine's starting performance has deteriorated if those times exceed a preset threshold based on the time of normal engine startup and are continuously increasing; identifies deterioration of electrical components related to engine startup by diagnosis based on the current value level of the battery measured by the ammeter at the time of engine startup; or identifies deterioration of fuel supply system components or fuel injection system components of the engine by diagnosis based on the rotational speed at which the engine rises with a fixed fuel flow rate from the fuel flow rate measured by the fuel flow meter, and outputs the results of the diagnosis. [Effects of the Invention]

[0010] According to the present invention, it is possible to easily diagnose deterioration in engine performance during startup and to improve the accuracy of the diagnosis. Furthermore, it becomes possible to narrow down the electrical and fuel system components that have deteriorated, thereby improving the efficiency of machine maintenance. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing a construction machine equipped with a diagnostic device for diagnosing deterioration of engine starting performance according to the embodiment of this construction machine. [Figure 2] This is a schematic diagram showing a diagnostic device for diagnosing deterioration in the engine starting performance of construction machinery. [Figure 3]This flowchart shows the series of operations involved in data collection, processing, and diagnosis during engine startup. [Figure 4] Figure 3 is a flowchart showing the details of data collection. [Figure 5] Figure 3 is a flowchart showing the detailed data processing within the arithmetic unit. [Figure 6] Figure 3 is a flowchart showing the detailed data processing within the diagnostic device. [Figure 7] This flowchart shows the details of data diagnosis for electrical components within the diagnostic device shown in Figure 3. [Figure 8] This flowchart shows the details of data diagnostics for electrical components using current values. [Figure 9] Figure 3 is a flowchart showing the details of data diagnosis for fuel system components within the diagnostic device. [Figure 10] This flowchart shows the details of data diagnostics for fuel system components using fuel flow rate values. [Modes for carrying out the invention]

[0012] Hereinafter, an embodiment of the engine starting performance deterioration diagnostic device for construction machinery according to the present invention will be described with reference to the drawings. The engine starting performance deterioration diagnostic device 2 for construction machinery according to this embodiment is, for example, mounted on a construction machine 1 and is a device for diagnosing the starting performance of an engine 3 incorporated into the construction machine 1. Here, an example of a construction machine is given, but the present invention is also applicable to other machines that operate using a hydraulic pump mechanically connected to an engine as a power source.

[0013] Figure 1 is a schematic diagram showing a construction machine equipped with an engine startability deterioration diagnostic device according to an embodiment of this device.

[0014] As shown in Figure 1, the construction machine 1 mainly consists of an engine 3 and an engine startability deterioration diagnostic device 2 for diagnosing the starting performance of the engine 3. The construction machine 1 is also equipped with a fuel pump 7 for supplying fuel to the engine 3, a starter 8 that operates when the engine 3 is started, a battery 4 that supplies power to the starter 8, a voltmeter 5 for measuring the voltage of the battery 4, an ammeter 6 for measuring the current of the battery 4, and an alternator 9 that generates electricity and charges the battery 4 when the engine 3 is running. Furthermore, a hydraulic pump 10 is mechanically connected to the output shaft 11 of the engine 3 by a spline connection. The hydraulic pump 10 is, for example, a swashplate type variable displacement hydraulic pump that changes its capacity according to tilt angle data measured by an attached tilt angle measuring device 12.

[0015] The battery 4, starter 8, and alternator 9 are components related to starting the engine 3 and constitute the electrical system components of the engine 3. On the other hand, the fuel pump 7 is a component related to supplying fuel to the engine 3 and constitutes the fuel system components of the engine 3. In addition to the fuel pump 7, other fuel system components include, for example, injectors (not shown) and fuel filters (not shown).

[0016] The engine starting performance degradation diagnosis device 2 consists of a controller 13, to which an engine tachometer 14, a voltmeter 5, an ammeter 6, a tilt angle measuring device 12, a fuel flow meter 15, and a hydraulic oil thermometer 16 are connected. The engine tachometer 14 measures the rotational speed of the engine 3 and outputs the measured result to the controller 13. The engine tachometer 14 is configured to measure the rotational speed of the engine 3, for example, by detecting the number of teeth passed by the teeth processed on the flywheel. Also, the engine tachometer 14 is driven by the battery 4 via the engine 3. The voltmeter 5 measures the voltage of the battery 4 at the start of the engine 3 and outputs the measured result to the controller 13. The ammeter 6 measures the current of the battery 4 at the start of the engine 3 and outputs the measured result to the controller 13. The tilt angle measuring device 12 measures the tilt angle of the hydraulic pump 10 connected to the engine 3 and outputs the measured result to the controller 13. The fuel flow meter 15 measures the flow rate of the fuel supplied to the engine 3 and outputs the measured result to the controller 13. The hydraulic oil thermometer 16 measures the temperature of the hydraulic oil flowing through the hydraulic pump 10 connected to the engine 3 and outputs the measured result to the controller 13.

[0017] The controller 13 is composed of, for example, a CPU (Central Processing Unit) that executes operations, a ROM (Read Only Memory) as a secondary storage device that records a program for operations, a RAM (Random Access Memory) as a temporary storage device that stores the progress of operations and temporary control variables, and a master clock that serves as a reference for the operation cycle and time measurement of the CPU. It is configured by a microcomputer that combines these components, and controls each component of the construction machine 1 including the engine 3 by executing the stored program.

[0018] Fig. 2 shows a schematic configuration diagram of the engine starting performance degradation diagnosis device of the construction machine.

[0019] The controller 13 includes a calculation unit 211, a diagnostic device 212, and a storage device 213. The calculation unit 211 performs various calculations related to control. For example, the calculation unit 211 calculates the time it takes for the engine speed to reach a preset threshold based on engine speed data measured by the engine tachometer 14. 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 calculated by the calculation unit 211 with a preset reference value. The storage device 213 temporarily stores the calculated data and other information.

[0020] The engine starting performance deterioration diagnostic device 2 is equipped with a monitor 21, which is installed, for example, in the cab room of the construction machine 1. The monitor 21 displays the output from the diagnostic device 212, allowing operators and workers during operation to check the diagnostic results and status via the monitor 21.

[0021] Referring to Figure 3, the series of machine operations involved in data collection, processing, and diagnosis during engine startup, related to the diagnosis of engine 3's starting performance deterioration, will be explained. The data collection work here mainly involves data measured by the engine tachometer 14, ammeter 6, hydraulic oil temperature gauge 16, and tilt angle measuring device 12.

[0022] First, engine 3 is turned on (see step S301). Next, controller 13 determines whether the key position signal and engine status signal are above a preset threshold (see step S302). The key position signal is displayed as an integer from 0 to 3, for example, where 0 indicates "OFF", 1 indicates "accessory state", 2 indicates "ON state", and 3 indicates "start (cranking) state". The engine status signal is displayed as an integer from 0 to 1, for example, where 0 indicates "stopped state" and 1 indicates "engine running state". The threshold is set as, for example, "2" for the key position signal and "0" for the engine status signal.

[0023] If it is determined that the value is less than the threshold, the determination in step S302 is repeated. On the other hand, if it is determined that the key position signal and the engine status signal are greater than or equal to the threshold, power is supplied from the battery 4 to the tachometer 14 (i.e., the tachometer 14 is energized). At the same time that the tachometer 14 is energized, the hydraulic oil temperature gauge 16 is also energized (see step S303), and data acquisition to the storage device 213 begins (see step S304).

[0024] In step S305, following step S304, the collected data is processed using a series of processes described later. Then, using the processed data, a data diagnosis is performed in step S306. After the data diagnosis is completed in step S306, the engine shutdown sequence is started in the following steps S307 and beyond. Details of steps S303 to S306 will be explained later.

[0025] In step S307, following step S306, it is determined whether the idle speed has been maintained for a predetermined time. In this embodiment, the determination condition is whether a predetermined time, for example 30 seconds, has elapsed after reaching the idle speed, which is to confirm whether data from engine startup has been collected. It is sufficient if the data for engine startup, such as rotation speed, current value, hydraulic oil temperature, and tilt angle, used for the determination have been collected, and the time is not limited to 30 seconds as shown in this example, but can be appropriately changed depending on the actual situation.

[0026] In this embodiment, if it is determined that 30 seconds have not elapsed since the rotational speed reached the idle speed (see step S307, NO determination), the determination process in step S307 is repeated until 30 seconds have elapsed since the rotational speed reached the idle speed. On the other hand, if it is determined that 30 seconds have elapsed since the rotational speed reached the idle speed (see step S307, YES determination), it is determined whether or not to continue the work in order to stop the engine (see step S308).

[0027] After step S307, in step S308, the diagnostic device 212 determines whether or not to continue the work. One method of determination is to detect the increase in rotational speed from idle speed to steady rotational speed during work. However, during work, the tilt angle of the hydraulic pump 10 is increased in order to increase the amount of hydraulic fluid supplied from the hydraulic pump 10 to, for example, the hydraulic motor for travel (not shown) and the hydraulic cylinder for the front equipment (not shown). Therefore, by measuring the change in the tilt angle at this time using the tilt angle measuring device 12, it is possible to determine whether or not to continue the work. If it is determined that the work should be continued (see step S308, YES determination), the determination is repeated.

[0028] On the other hand, if it is determined that the operation cannot be continued (see step S308, NO determination), the determination loop in step S308 is exited, and the rotation speed of engine 3 is reduced to idle speed (see step S309). After that, the engine is stopped (see step S310). With this, data collection at engine startup is completed.

[0029] Next, referring to Figures 4, 5, 6, 7, 8, 9, and 10, the three important processes in the engine starting performance diagnosis procedure using the construction machinery engine starting performance deterioration diagnosis device 2, whose overall outline was explained in Figure 3, will be explained as follows: data collection (Figure 4), data processing (Figures 5 and 6), and data diagnosis (Figures 7, 8, 9, and 10).

[0030] First, Figure 4 shows the data collection procedure.

[0031] First, the parameter n for data counting is set to an initial value of n=0 (see step S401). Simultaneously, counting begins at a predetermined period based on the master clock built into the microcontroller (see step S402), and each time measurement data is taken by the ammeter 6, fuel flow meter 15, hydraulic oil temperature meter 16, and tilt angle measuring device 12 in synchronization with the counting, 1 is added to the data count parameter (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).

[0032] Next, it is determined whether the engine is running or not based on the engine speed data (see step S405). If the engine speed data is greater than 0 (see step S405, YES determination), 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 step S405, NO determination), 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 status signal is "1". The controller 13 detects that engine 3 has started by receiving these signals.

[0033] The fuel consumed by the engine is measured by the fuel flow meter 15 (see step S407), and it is determined whether fuel is flowing (see step S408). If it is determined that the fuel flow rate is 0 (see step S408, NO determination), 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 0 (see step S408, YES determination), 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).

[0034] 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 step S411, YES determination), the process proceeds to the next step S412.

[0035] Next, for the retrieved engine speed data, it is determined whether the current engine speed data f(n) is less than or equal to the previous engine speed data f(n-1) (see step S412). If it is determined that the current engine speed f(n) is greater than the previous data f(n-1) (see step S412, NO determination), it is determined that the current engine speed f(n) has not yet reached 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 less than or equal to the previous data f(n-1) (see step S412, YES), it is determined that idle speed has been reached.

[0036] In step S412, if it is determined that the current engine speed f(n) has reached the idle speed (see step S412, YES determination), the data for engine speeds f(n+1) and beyond is deleted (see step S413), and the process proceeds to step S414. In step S414, the data obtained up to the point where the engine speed f(n) is reached is stored in the storage device 213, and data processing is performed.

[0037] Next, Figure 5 shows the data processing procedure. Here, we calculate the feature data that will be used in the data diagnosis performed in a later step.

[0038] First, the current value, fuel flow rate, and rotational speed data are retrieved from the storage device 213 (see step S501). Next, it is determined whether the current value is 0 or not (see step S502). This determines that the timing of the current value rising (the timing when the current value reaches its maximum value) during engine startup is set as the engine startup time. If the current value is a number other than 0 (see step S502, YES determination), the rotational speed data and time information at that time are extracted (see step S503) and set as the starting point (see step S504). On the other hand, if the current value is 0 (see step S502, NO determination), the process is repeated again from step S501.

[0039] Next, it is determined whether the fuel flow data is 0 or not (see step S505). This determines that the initial combustion speed is the timing when the fuel begins to flow. If the fuel flow data shows a value other than 0 (see step S505, YES determination), the rotation speed data and time data at that time are extracted and set as the initial combustion speed (see step S506). On the other hand, if the fuel flow data shows 0 (see step S505, NO determination), the process is repeated from step S501. After that, the time when the self-sustaining operation speed (750 rpm) is reached is calculated and stored in the memory device 213 (see step S507).

[0040] The stored time information is retrieved, and first, the time (t1) from the starting point to reaching the initial ignition speed is calculated (see step S508). Next, the time (t2) from the initial ignition speed to reaching the self-sustaining operation speed is calculated (see step S509). After that, the t1 and t2 data calculated in steps S508 and S509 are stored in the storage device 213 (see step S510), and data processing is completed.

[0041] Next, features are calculated using the t1 and t2 data calculated above. Filtering is performed to account for data variability. Therefore, the flow shown above is repeated several times to obtain multiple data points. After preparing multiple data points in advance, the process shown in Figure 6 is performed.

[0042] Next, Figure 6 shows the data processing procedure. Here, the feature data calculated in the previous step is used to diagnose the deterioration of engine parts.

[0043] First, the parameter N for data counting is set to an initial value of N=0 (see step S601). Similarly, the parameter P for data counting is set to an initial value of P=0 (see step S602).

[0044] The stored data is retrieved in step S510 of the data processing in Figure 5 (see step S603). Next, in order to eliminate the influencing factor of drag during cold starts, only data with a hydraulic oil temperature of 30°C or higher is considered valid data. In this embodiment, only data with a hydraulic oil temperature of 30°C or higher is considered valid data, but this is not the only way to do so.

[0045] If the hydraulic fluid temperature is 30°C or higher (see step S604, YES determination), proceed to the next step, S605. On the other hand, if the hydraulic fluid temperature is less than 30°C (see step S604, NO determination), repeat the process from step S603.

[0046] Next, in order to remove outliers from the data, the lower and upper limits of the variation measured during normal startup are measured in advance, and the data that falls between these limits is set as valid data. If t1 and t2 are within the set range (no outliers) (see step S605, YES judgment), 1 is added to N (see step S609), and it is then determined whether N is 9 or greater (step S610). In this embodiment, the data is described as being set to 9, but it is not limited to this. If N is less than 9 (see step S610, NO judgment), the process is repeated from step S603.

[0047] If N is 9 or more (see step S610, YES determination), the data is stored (see step S611). Furthermore, the median is calculated using these 9 data points (see step S612), followed by the mean (see step S613), and the calculated features are stored in the memory device 213 (see step S614), and the data processing flow ends.

[0048] On the other hand, if t1 and t2 are outside the set range (there are outliers) (see step S605, NO determination), 1 is added to parameter P (see step S606), and it is determined whether P is 3 or not (see step S607).

[0049] If P is 3 or greater (see step S607, YES judgment), it is further determined whether it is 3 consecutive occurrences (see step S608). If it is 3 consecutive occurrences (see step S608, YES judgment), it is stored in the memory device 213 and the judgment ends. On the other hand, if the 3 occurrences are not consecutive (see step S608, NO judgment), the process is repeated from step S602 according to the flow. If P is less than 3 (see step S607, NO judgment), the process is repeated from step S603 according to the flow. If an outlier is calculated 3 times in a row, it is determined to be an abnormality and the process ends.

[0050] Figures 7, 8, 9, and 10 show the data diagnostic procedure.

[0051] First, Figure 7 shows the procedure for determining deterioration during the time (t1) from engine startup to reaching the initial combustion speed.

[0052] For the parameter n used for data counting, an initial value n=0 is set (see step S701), and then 1 is added to n (see step S702). Subsequently, the feature data t1 is retrieved (see step S703).

[0053] Next, it is determined whether the retrieved feature is greater than threshold a (see step S704). In this embodiment, threshold a is the maximum possible time from 0 rpm to 250 rpm during normal engine startup, but it can be arbitrarily set by the administrator and is not limited to this value.

[0054] If the feature size is greater than threshold a (see step S704, YES judgment), proceed to step S705. On the other hand, if the feature size is less than or equal to threshold a (see step S704, NO judgment), the process is repeated from step S701 according to the flow. In step S705, if the flow has not been repeated 5 times, i.e., n=5 (see step S705, NO judgment), the process is repeated from step S702 according to the flow. On the other hand, if the flow has been repeated 5 times, i.e., n=5 (see step S705, YES judgment), proceed to step S706. Next, it is determined whether data n has been received 5 times consecutively (see step S706). If data n has been received 5 times consecutively (see step S706, YES judgment), i.e., if the data is continuously increasing, it is diagnosed that the electrical components are deteriorating (see step S707), the result is notified to the administrator (see step S708), and the data diagnosis is completed. On the other hand, if data n has not been received for five consecutive times (see step S706, NO determination), the process is repeated from step S702 according to the flow. In this embodiment, the determination value n for consecutive counts is set to 5, but it can be set arbitrarily by the administrator and is not limited to that value.

[0055] In step S705 above, it is determined whether n is 5 or greater (see step S705). If n is 5 or greater (see step S705, YES determination), it is further determined whether it is 5 consecutive occurrences (see step S706). If it is 5 consecutive occurrences (see step S706, YES determination), it is diagnosed as deterioration of electrical components (see step S707), and the administrator is notified accordingly (see step S708). After that, the data diagnosis is completed. If it is not 5 consecutive occurrences (see step S706, NO determination), the process is repeated from step S702.

[0056] If n is less than 5 in step S705, the process is repeated from step S702, as described above.

[0057] Furthermore, a determination is made based on the measurement value from the ammeter 6. Figure 8 shows the details. The contents of Figure 8 are the same as those performed in part (A) of Figure 7.

[0058] The current value is retrieved from the storage device 213 (see step S801), and it is determined whether the current value exceeds threshold b (see step S802). This is intended to identify further degraded electrical components of the engine. In this embodiment, threshold b is the maximum current value shown when the engine is started normally, but it can be arbitrarily set by the administrator and is not limited to this value.

[0059] If the maximum current value at engine startup is greater than the set threshold, it is unlikely that there is a problem with the power supply side (battery or alternator), and it is determined that the starter, which operates using that power, is not functioning correctly. On the other hand, if the maximum current value at engine startup is below the set threshold, it is determined that the necessary power is not being supplied, and the power supply side (battery or alternator) is not functioning correctly.

[0060] If the current value exceeds threshold b (see step S802, YES judgment), it is determined that there is deterioration in electrical components other than the battery and alternator (starter) (see step S803). On the other hand, if the current value does not exceed threshold b (see step S802, NO judgment), it is determined that there is deterioration in the battery and alternator (see step S804). The above judgment results are notified to the administrator (see step S708), and the data diagnosis is completed.

[0061] Unlike passenger cars, construction machinery has its engine and hydraulic pump shafts permanently connected. When the engine starts, the hydraulic pump shaft is rotated, resulting in the greatest load during operation and an increase in battery current. By monitoring the battery current during engine startup, it becomes possible to understand the battery's condition, which led to this technology proposal.

[0062] As demonstrated in this embodiment, the proposed technology makes it possible to determine the deterioration of electrical components and to narrow down (identify) the deteriorated electrical components.

[0063] Next, Figure 9 shows the procedure for data diagnosis of the time (t2) from the initial combustion speed to the independent operation speed.

[0064] For the parameter n used for data counting, an initial value n=0 is set (see step S901), and then 1 is added to n (see step S902). Subsequently, the feature data t2 is retrieved (see step S903).

[0065] Next, it is determined whether the retrieved feature is greater than the threshold d (see step S904). In this embodiment, the threshold d is the maximum possible time from 250 rpm to 750 rpm during normal engine startup, but it can be arbitrarily set by the administrator and is not limited to this value.

[0066] If the feature size is greater than the threshold d (see step S904, YES judgment), proceed to step S905. On the other hand, if the feature size is less than or equal to the threshold d (see step S904, NO judgment), the process is repeated from step S901 according to the flow. Next, in step S905, if n is not 5 (see step S905, NO judgment), the process is repeated from step S902 according to the flow. On the other hand, if n is 5 (see step S905, YES judgment), it is then determined whether data n has been received 5 times consecutively (see step S906). If data n has been received 5 times consecutively (see step S906, YES judgment), that is, if the data is continuously increasing, it is diagnosed that the fuel supply system / fuel injection system components are deteriorating (see step S907), the result is notified to the administrator (see step S908), and the data diagnosis is completed. On the other hand, if data n has not been received for five consecutive times (see step S906, NO determination), the process is repeated from step S902 according to the flow. In this embodiment, the determination value n for consecutive counts is set to 5, but it can be set arbitrarily by the administrator and is not limited to this.

[0067] In step S905 above, it is determined whether n is 5 or greater (see step S905). If n is 5 or greater (see step S905, YES determination), it is further determined whether it is 5 consecutive occurrences (see step S906). If it is 5 consecutive occurrences (see step S906, YES determination), it is diagnosed as deterioration of fuel system components (see step S907), and the administrator is notified accordingly (see step S908). After that, the data diagnosis is completed. If it is not 5 consecutive occurrences (see step S906, NO determination), the process is repeated from step S902.

[0068] If n is less than 5 in step S905, the process is repeated from step S902, as described above.

[0069] Furthermore, a determination is made based on measurements taken by the fuel flow meter 15. Figure 10 shows the details. The contents of Figure 10 are the same as those performed in section (B) of Figure 9. This is intended to identify further deteriorated parts of the engine's fuel system.

[0070] The engine speed and fuel flow rate values ​​(fuel flow rate values ​​for each rotation speed) are retrieved from the storage device 213 (see step S1001), and the integrated fuel flow rate (e) from the initial combustion speed to the self-sustaining operation speed is calculated (see step S1002). Then, the amount of increase in engine speed (f) from the initial combustion speed to the self-sustaining operation speed is calculated (see step S1003). Here, the initial combustion speed is the rotation speed at which the engine starts to rise due to the ignition of the fuel injected into the cylinder at engine startup and the resulting explosive force, and the self-sustaining operation speed is the rotation speed at which the engine continues to rotate even after the idle speed is reached and the starter is released.

[0071] Furthermore, the engine speed increase from the initial combustion speed to the self-sustaining operating speed (f) is divided by the integrated fuel flow rate (e) from the initial combustion speed to the self-sustaining operating speed to calculate the engine speed increase per unit amount of fuel flow rate (f / e). By comparing this value with the engine speed increase per unit amount of fuel flow rate (g) shown during normal machine startup, it is determined whether the problem lies with the fuel injection system components or the fuel supply system components (see step S1004). If the engine speed increase per unit amount of fuel flow rate (f / e) is smaller than the engine speed increase per unit amount of fuel flow rate (g) shown during normal startup (see step S1004, YES judgment), it is determined that the rotational speed corresponding to the fuel flow rate is not being maintained, and although fuel is being supplied, injection is not occurring normally, and it is determined that the fuel injection system components are deteriorated (see step S1005). On the other hand, if the engine speed increase per unit amount of fuel flow (f / e) is equal to the engine speed increase per unit amount of fuel flow (g) shown during normal starting (see step S1004, NO determination), it is determined that the engine speed is controlled to match the supplied fuel, and that there is deterioration in the fuel supply system components or fuel injection system components (see step S1006). In this case, since engine control is involved, no identification is performed.

[0072] If the value of f / e is smaller than the value of g (see step S1004, YES judgment), it is determined that the rotation speed corresponding to the fuel flow rate is not being maintained, and although fuel is being supplied, fuel injection is not being performed normally, and it is determined that there is deterioration of the fuel injection system components (see step S1005). On the other hand, if the value of f / e is equal to the value of g (see step S1004, NO judgment), the engine speed is controlled to match the supplied fuel, so no identification is performed, and it is determined that there is deterioration of either the fuel supply system components or the fuel injection system components (see step S1006). Furthermore, after the above determination is notified to the administrator (see step S908), the data diagnosis is completed.

[0073] As mentioned earlier, unlike passenger cars, construction machinery has the engine and hydraulic pump shafts constantly connected. When starting the engine, the hydraulic pump shaft is rotated, placing a large load on it. Furthermore, due to the influence of external factors, it does not become a steady state like when a passenger car starts up (before clutch engagement), and there is variability in the data. We believe that by monitoring the trend of the data, including this variability, it will be possible to understand the performance state from the initial ignition speed to the autonomous operation speed, which led to this technology proposal.

[0074] As demonstrated in this embodiment, the proposed technology makes it possible to determine the deterioration of fuel system components and to narrow down (identify) the deteriorated fuel system components.

[0075] In this embodiment, notification to the administrator is provided, for example, by displaying information on the monitor 21. However, the notification method may also be provided via signals, alarms, etc., and is not particularly limited as long as it is recognizable by the administrator, operator, or worker. Furthermore, if there are no abnormalities in the electrical or fuel system components, information indicating that there are no abnormalities may be displayed on the monitor 21, for example, to inform the administrator, operator, or worker. In addition, the engine startability deterioration diagnostic device 2 according to this embodiment can be applied to all models, regardless of the engine type or the model on which it is installed.

[0076] As described above, the engine startability deterioration diagnostic device 2 for the construction machine 1 according to this embodiment comprises an engine tachometer 14 for measuring the rotational speed of the engine 3, an ammeter 6 for measuring the current of the battery 4 that supplies power to the starter 8 that operates when the engine 3 is started, and a fuel flow meter 15 for measuring the fuel flow rate of the engine 3. The device 211 calculates the time until the rotational speed of the engine 3 reaches a preset threshold based on the rotational speed data of the engine 3 measured by the engine tachometer 14. The timing at which the current value of the battery 4 shows its maximum value when the engine 3 is started is set as the starting point (step S504), and the timing at which the fuel flow rate of the engine 3 shows a value other than 0 is set as the initial combustion rotational speed (step S506). The device 211 then calculates the time from when the engine 3 is started until the initial combustion rotational speed is reached (t1) and the time from the initial combustion rotational speed until the self-sustaining operation rotational speed is reached (t2). (Steps S508, S509) The calculation unit 211 performs the calculation, and if the times (t1, t2) calculated by the calculation unit 211, when viewed in time series, exceed the thresholds (a, d) set in advance based on the time of normal engine start-up of the engine 3 (Steps S704, S904), and are continuously increasing (Steps S705, S706, S905, S906), it diagnoses that the starting performance of the engine 3 has deteriorated (Steps S707, S907), and the starting of the engine 3 The system includes a diagnostic device 212 that, at times, identifies deterioration of electrical components related to starting the engine 3 by diagnosing based on the current value level of the battery 4 measured by the ammeter 6 (step S802), or identifies deterioration of fuel supply system components or fuel injection system components of the engine 3 by diagnosing based on the rotational speed at which the engine 3 increases with a fixed fuel flow rate measured by the fuel flow meter 15 (step S1004), and outputs the results of the diagnosis.

[0077] In a diagnosis based on the current value level of the battery 4 measured by the ammeter 6 when the engine 3 is started (step S802), the diagnostic device 212 identifies deteriorated electrical components of the engine 3 by comparing the current value level when the engine 3 is started with a preset threshold (b) based on the current value shown when the engine 3 is started, and dividing the cases into those where the threshold (b) is not exceeded and those where the threshold (b) is exceeded (steps S803, S804).

[0078] The diagnostic device 212, in a diagnosis based on the fuel flow rate measured by the fuel flow meter 15 and the rotational speed at which the engine 3 rises with a fixed fuel flow rate (step S1004), identifies deteriorated fuel system components of the engine 3 by comparing the rotational speed level (f / e) at which the engine 3 rises with a fixed fuel flow rate with the rotational speed (g) at which the engine 3 rises with a fixed fuel flow rate during normal starting of the engine 3, and classifying cases into those that are greater than or less than that (steps S1005, S1006).

[0079] The diagnostic device 212, in a diagnosis based on the current value level of the battery 4 measured by the ammeter 6 when the engine 3 is started (step S802), compares the current value level when the engine 3 is started with a preset threshold (b) based on the current value shown when the engine 3 is started, and divides the case into those where the threshold (b) is not exceeded and those where the threshold (b) is exceeded, thereby identifying deteriorated electrical components of the engine 3 (steps S803, S804), and the fuel flow rate measured by the fuel flow meter 15 In a diagnosis based on the rotational speed that increases with a fixed fuel flow rate of the engine 3 (step S1004), the rotational speed level (f / e) that increases with a fixed fuel flow rate of the engine 3 is compared with the rotational speed (g) that increases with a fixed fuel flow rate during normal startup of the engine 3, and by dividing the cases into those that are higher and those that are lower, deteriorated fuel system components of the engine 3 are identified (steps S1005, S1006), thereby simultaneously diagnosing the deterioration of electrical system components and fuel system components of the engine 3 during startup.

[0080] The diagnostic device 212 calculates the rotational speed level (f / e) that rises with a fixed fuel flow rate of the engine 3 by dividing the amount of increase in engine speed (f) from the initial combustion speed to the self-sustaining operation speed (e) by the integrated value of the fuel flow rate from the initial combustion speed to the self-sustaining operation speed (step S1004).

[0081] The diagnostic device 212 diagnoses that electrical components related to starting the engine 3 are deteriorating (step S707) if the time (t1) from the start of the engine 3 to reaching the initial combustion speed exceeds a preset threshold (a) based on the time of normal engine startup when viewed in a time series (step S704) and is continuously increasing (steps S705, S706). The diagnostic device 212 diagnoses that fuel system components of the engine 3 are deteriorating (step S907) if the time (t2) from the initial combustion speed to reaching the self-sustaining operation speed exceeds a preset threshold (d) based on the time of normal engine startup when viewed in a time series (step S904) and is continuously increasing (steps S905, S906).

[0082] According to this embodiment, deterioration in engine performance during startup can be easily diagnosed, and the diagnostic accuracy can be improved. Furthermore, it becomes possible to narrow down the electrical and fuel system components that have deteriorated, thereby improving the efficiency of machine maintenance.

[0083] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design modifications can be made without departing from the concept of the present invention as described in the claims. [Explanation of Symbols]

[0084] 1. Construction machinery 2. Engine starting performance deterioration diagnostic device 3 Engines 4 batteries 5. Voltmeter 6 Ammeter 7. Fuel pump 8 Starters 9 Alternator 10 Hydraulic pumps 11 Output shaft 12. Tilt Angle Measuring Device 13 Controllers 14. Engine Tachometer 15 Fuel flow meter 16 Hydraulic oil temperature gauge 21 monitors 211 Arithmetic equipment 212 Diagnostic device 213 Storage device

Claims

1. A diagnostic device for diagnosing deterioration of engine starting performance in a construction machine, comprising: an engine tachometer for measuring the rotational speed of the engine; an ammeter for measuring the current of the battery that supplies power to the starter that operates when the engine is started; and a fuel flow meter for measuring the fuel flow rate of the engine, A calculation device that calculates the time from engine startup to reaching the initial combustion speed and the time from the initial combustion speed to reaching the self-sustaining operation speed, by setting the timing when the battery current value reaches its maximum value when the engine is started as the starting point, and the timing when the engine fuel flow rate shows a value other than zero as the initial combustion speed. A diagnostic device for diagnosing deterioration of engine starting performance in construction machinery, characterized by comprising: a diagnostic device that diagnoses that the engine starting performance has deteriorated if, when viewed in a time series, those times calculated by the calculation device exceed a threshold set in advance based on the time of normal engine starting and are continuously increasing; a diagnostic device that identifies deterioration of electrical system components related to engine starting by diagnosing based on the current value level of the battery measured by the ammeter at the time of engine starting; or a diagnostic device that identifies deterioration of fuel supply system components or fuel injection system components of the engine by diagnosing based on the rotational speed at which the engine rises with a fixed fuel flow rate from the fuel flow rate measured by the fuel flow meter, and outputs the results of the diagnosis.

2. In the engine starting performance deterioration diagnostic device for construction machinery according to claim 1, The diagnostic device is a diagnostic device for diagnosing deterioration of the starting performance of a construction machine, characterized in that, in a diagnosis based on the current value level of the battery measured by the ammeter when the engine is started, the current value level at the time of engine start-up is compared with a threshold value that is set in advance based on the current value that is shown when the engine is started normally, and the device is divided into cases where the threshold value is not exceeded and cases where the threshold value is exceeded, thereby identifying deteriorated electrical components of the engine.

3. In the engine starting performance deterioration diagnostic device for construction machinery according to claim 1, The diagnostic device is a diagnostic device for diagnosing deterioration of the engine's starting performance in a construction machine, characterized in that, in a diagnosis based on the fuel flow rate measured by the fuel flow meter and the rotational speed at which the engine's rotational speed rises with a fixed fuel flow rate is compared to the rotational speed at which the engine's rotational speed rises with a fixed fuel flow rate during normal engine startup, it identifies deteriorated fuel system components of the engine by dividing the engine into cases where the rotational speed is higher or lower than the rotational speed at which the engine rises with a fixed fuel flow rate during normal engine startup.

4. In the construction machinery engine starting performance deterioration diagnostic device according to claim 1, The diagnostic device is In a diagnosis based on the current level of the battery measured by the ammeter when the engine is started, the current level at the time of engine startup is compared with a preset threshold based on the current level shown when the engine is started normally, and the system identifies deteriorated electrical components of the engine by dividing the cases into those that do not exceed the threshold and those that do exceed the threshold. In a diagnosis based on the fuel flow rate measured by the fuel flow meter and the rotational speed at which the engine increases with a fixed fuel flow rate, the engine's deteriorated fuel system components are identified by dividing the rotational speed level at which the engine increases with a fixed fuel flow rate into cases where it is higher than or lower than the rotational speed at which the engine increases with a fixed fuel flow rate during normal engine startup. A diagnostic device for diagnosing deterioration of the starting performance of construction machinery, characterized by simultaneously diagnosing deterioration of the electrical components and fuel system components of the engine during engine startup.

5. In the construction machinery engine starting performance deterioration diagnostic device according to claim 3, The diagnostic device is characterized by calculating the engine starting performance deterioration diagnostic device for construction machinery by dividing the amount of increase in engine speed from the initial combustion speed to the self-sustaining operation speed by the integrated value of the fuel flow rate from the initial combustion speed to the self-sustaining operation speed, thereby calculating the rotational speed level that rises with a fixed amount of fuel flow rate for the engine.

6. In the construction machinery engine starting performance deterioration diagnostic device according to claim 1, The diagnostic device is If the time from engine startup to reaching the initial combustion speed exceeds a preset threshold based on the time of normal engine startup and is continuously increasing, it is diagnosed that the electrical components related to engine startup are deteriorating. A diagnostic device for diagnosing deterioration of the engine's starting performance in construction machinery, characterized in that, when the time from the initial combustion speed to reaching the self-sustaining operating speed exceeds a preset threshold based on the time of normal engine startup and is continuously increasing, it diagnoses that the engine's fuel system components are deteriorating.

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