JP2005201133A - Device and method of detecting engine state amount of construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and method of detecting engine state amount of a construction machine capable of previously detecting abnormality of a component related to engine fuel injection control. <P>SOLUTION: The detecting device comprises a rotation speed sensor 15 for detecting the engine speed, a throttle 14 for outputting a command signal according to an operation position, a governor actuator 16 for adjusting fuel injection amount of the engine and detecting the operating angle, an engine controller 17 for storing a first threshold value N<SB>A</SB>and a second threshold value N<SB>B</SB>(N<SB>B</SB>< N<SB>A</SB>) related to the engine speed, stopping the engine when the engine speed reaches the first threshold value N<SB>A</SB>, and controlling the engine speed to be low when the engine speed reaches the second threshold value N<SB>B</SB>, and a data recorder 19 for storing a third threshold value N<SB>C</SB>(N<SB>C</SB>< N<SB>B</SB>), and, when the engine speed reaches the third threshold value N<SB>C</SB>, storing the engine speed, the operation position of the throttle 14, the operating angle of the governor actuator 16 and the like while creating their time-varying relation, and outputting the display signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a construction machine such as a hydraulic excavator, and more particularly to an engine state quantity detection device and a detection method for a construction machine that diagnose parts related to engine fuel injection control.

  Construction machines such as hydraulic excavators generally operate front working machines and swiveling bodies, such as booms, arms, and buckets, by hydraulic actuators such as hydraulic cylinders and hydraulic motors. These hydraulic actuators are driven by an engine. The pump operates by being supplied with the discharge pressure oil from the hydraulic pump. The engine includes a fuel injection device that sprays fuel into a combustion chamber (cylinder), and a governor mechanism that controls the fuel injection device. This governor mechanism includes a governor actuator that operates according to the target engine speed, etc., input by the operator using the throttle, and the fuel injection amount of the fuel injection device is adjusted by this governor actuator to control the engine speed. It is supposed to be. By the way, for example, if the engine speed increases for some reason and an overspeed abnormality (overrun) occurs, the inertial force of the connecting rod of the engine increases, and the connecting rod and crankshaft may be damaged.

  Here, conventionally, for example, an engine overrun prevention device for a vehicle provided with overrun detection means for detecting engine overrun and overrun control means for controlling the vehicle speed to be reduced when overrun is detected. It is disclosed (for example, see Patent Document 1). In this prior art, when the vehicle travels down an inclined surface or the like, if it is accelerated by its own weight or the like and the engine is reversely driven to exceed the allowable engine speed, for example, the engine speed is detected. An overrun is detected by an overrun detection means such as a sensor, and the overrun control means operates a brake, for example, to reduce the vehicle speed and suppress an increase in engine speed due to reverse drive. Is to be prevented beforehand.

JP 7-179137 A

However, there are the following problems in the above-described prior art.
In other words, in addition to the reverse driving of the engine described above, the engine overrun becomes higher due to abnormalities in the governor actuator, the dustiness of the governor mechanism due to dust and poor lubrication, etc., and proper fuel injection control is performed. There is a case where it is not broken.

  By the way, large excavators and the like are used for debris excavation work in a vast work site, for example, and are generally continuously operated in order to improve productivity. Therefore, when an overrun occurs due to an abnormality in the governor actuator, the governor mechanism, etc. and an engine failure occurs, the production work by the hydraulic excavator is interrupted, so the operation of the production plan must be changed. Therefore, before the engine is stopped due to overrun, it is necessary to detect in advance the abnormality of the parts related to the fuel injection control of the engine.

  The present invention has been made in view of the above-described matters, and an object of the present invention is to detect an engine state quantity detection device and a detection method for a construction machine that can detect in advance an abnormality of a component related to engine fuel injection control. Is to provide.

  (1) In order to achieve the above object, an engine state quantity detection device for a construction machine according to the present invention relates to a rotational speed detection means for detecting the rotational speed of an engine mounted on the construction machine, and fuel injection control of the engine. An injection state quantity detection means for detecting a state quantity; a first storage means for storing a first threshold value related to the engine speed and a second threshold value set smaller than the first threshold value; A second storage means for storing a third threshold value set smaller than the threshold value of 2, and a stop means for stopping the engine when a detection value from the rotation speed detection means reaches the first threshold value; Protection means for controlling the engine speed low when the detection value from the rotation speed detection means reaches the second threshold value, and detection value from the rotation speed detection means has reached the third threshold value. Sometimes the speed detection hand Control means for generating a temporal relationship between the detected value from the detection value and the detected value from the injection state quantity detecting means, storing them in the second storage means, and outputting a display signal read from the second storage means; Is provided.

  In the present invention, the rotational speed of the engine is detected by the rotational speed detection means, and state quantities related to fuel injection control such as the throttle operating position and the governor actuator operating angle are detected by the injection state quantity detection means. When the detected engine speed reaches the first threshold value stored in the first storage means, the engine is stopped by the stop means, and the detected engine speed is stored in the first storage means and stored in the first storage means. When the second threshold value set lower than this threshold value is reached, the engine speed is controlled to be lower by the protection means. Further, when the detected engine speed reaches the third threshold value stored in the second storage means and set lower than the second threshold value, for example, the engine speed within a predetermined time (for example, about several minutes), A time-dependent relationship such as the throttle operating position and the governor actuator operating angle is generated and stored in the second storage means, and the display signal read from the second storage means is external to the construction machine (for example, the operating state of the construction machine). Etc.) or display means provided in the cab of the construction machine, and display on the display means. As a result, it is possible to see temporal relationships such as the engine speed, the throttle operating position, and the operating angle of the governor actuator in the office or the cab.

  In this way, in the present invention, it is possible to obtain a temporal relationship between, for example, the engine rotational speed and the operating angle of the governor actuator, which changes depending on the working environment of the construction machine, etc. Thus, it can be determined whether or not there is an abnormality in the parts related to the fuel injection control of the engine. Therefore, it is possible to detect in advance an abnormality of a part related to engine fuel injection control.

  (2) In the above (1), preferably, the apparatus further includes display means for displaying a display signal output from the control means outside the construction machine.

  (3) In the above (1), and preferably, it further includes display means for displaying the display signal output by the control means in the cab of the construction machine.

  (4) In order to achieve the above object, an engine state quantity detection method for a construction machine according to the present invention detects the number of revolutions of an engine mounted on the construction machine by means of a revolution number detection means, and relates to fuel injection control of the engine. The state quantity is detected by the injection state quantity detecting means, and the first threshold value related to the engine speed stored in the first storage means, the second threshold value set smaller than the first threshold value, and the second threshold value are set. Based on the third threshold value set smaller than the second threshold value stored in the storage means, the engine is stopped by the stop means when the detection value from the rotation speed detection means reaches the first threshold value. When the detection value from the rotation speed detection means reaches the second threshold value, the engine rotation speed is controlled to be lower by the protection means, and the detection value from the rotation speed detection means becomes the third threshold value. When it reaches A detection value from the rotational speed detection means and a detection value from the injection state quantity detection means are generated over time and stored in the second storage means, and the display signal read from the second storage means is stored. Output by control means.

  (5) In the above (4), preferably, the display signal output by the control means is displayed on the display means provided outside the construction machine.

  (6) In the above (4), and preferably, the display signal output by the control means is displayed on the display means provided in the cab of the construction machine.

  ADVANTAGE OF THE INVENTION According to this invention, abnormality of the components relevant to engine fuel injection control can be detected beforehand.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing the entire structure of a large hydraulic excavator as an example of a construction machine to which the present invention is applied.

  In FIG. 1, 1 is a large hydraulic excavator, 2 is an endless track crawler (crawler) which is a traveling means, 3 is a traveling body having the crawler belt 2 on both the left and right sides, and 4 is turned on the traveling body 3. A revolving structure 5 is provided, a driver's cab 5 is provided on the left side of the front part of the revolving structure 4, and a multi-joint type front working machine (excavation) is provided at the center of the front part of the revolving structure 4 so as to be lifted and lowered Working device). The left and right crawler belts 2 are operated by rotational drive of left and right traveling hydraulic motors (not shown), and the revolving structure 4 is driven by rotation of a turning hydraulic motor (not shown).

  Reference numeral 7 is a boom provided on the revolving body 4 so as to be rotatable in the vertical direction, 8 is an arm provided at the tip of the boom 7 so as to be rotatable, and 9 is a bucket provided at the tip of the arm 8 so as to be rotatable. The front work machine 6 includes the boom 7, the arm 8, and the bucket 9. The boom 7, the arm 8, and the bucket 9 are operated by a boom hydraulic cylinder 10, an arm hydraulic cylinder 11, and a bucket hydraulic cylinder 12, respectively.

  FIG. 2 is a circuit diagram illustrating an embodiment of the engine state quantity detection device for a construction machine according to the present invention, together with a main configuration of a related controller network.

  In FIG. 2, reference numeral 13 denotes a controller network for collecting various types of operation information of the excavator 1, and reference numeral 14 is provided in the operator cab 5 to instruct an operator to input a target rotational speed of an engine (not shown). A throttle, 15 is a rotational speed sensor for detecting the actual rotational speed of the engine, 16 is a governor actuator for adjusting the fuel injection amount of the engine, 17 is a command signal corresponding to the operating position of the throttle 14 and detection of the rotational speed sensor 15 An engine control that receives a signal or the like, performs predetermined arithmetic processing based on a deviation between the target engine speed and the actual engine speed, and outputs the generated control signal to the governor actuator 16 to control the engine speed. Device. The governor actuator 16 has a built-in angle sensor (not shown) for detecting its operating angle, and a detection signal of this angle sensor is input from the governor actuator 16 to the engine control device 17. .

  Reference numeral 18 is provided in the operator's cab 5, and a display for displaying various operation information (state quantities related to an engine system, an operation system, a hydraulic system, etc., which will be described later) and alarm information to the operator. This is a display control device that performs control related to display. Reference numeral 20 denotes a keypad which is connected to the display control device 19 and allows various data settings and screen switching to be performed by an operator's input operation.

  21 is connected to the engine control device 17 and the like (not shown, for example, an engine monitor unit to which a detection signal of a state quantity related to the engine is inputted) via the first network 22A, and the display control device 19 is connected via the second network 22B. (Not shown, for example, a hydraulic actuator (specifically, the left and right traveling hydraulic motors, the turning hydraulic motor, the boom hydraulic cylinder 10, the arm hydraulic cylinder 11, and the bucket hydraulic cylinder) 12) and the like, for example, a data recording device connected to an electric lever control device related to operation control, etc., for example, a hydraulic control device related to hydraulic control of a hydraulic pump driven by the engine and supplying pressure oil to the hydraulic actuator. is there. The data recording device 21 includes a state quantity related to the engine system of the hydraulic excavator 1 from the engine control apparatus 17 and the like, a state quantity related to the operation system from the electric lever control apparatus, a state quantity related to the hydraulic system from the hydraulic control apparatus, and the like. It is input continuously (for example, every second), and the state quantity data is stored.

  FIG. 3 is a characteristic diagram showing fluctuations in the engine speed controlled by the engine control device 17. In FIG. 3, the horizontal axis represents time and the vertical axis represents engine speed.

3, in the range of times t ₀ ~t _3, represents the normal variation of the engine speed. If the maximum target revolution speed is input indicated by the throttle 14, so initially the hydraulic actuator is not actuated, the engine speed is at high idle (predetermined no-load maximum speed) (time t ₀ ~t ₁ ). Then, when the hydraulic actuator starts to operate and an engine load is applied, the engine rotation speed is once suddenly lowered (so-called lag down), and then returns to the vicinity of a predetermined rated rotation speed and is stabilized (time t _{1 to} t ₂ ). Then, when the hydraulic actuator is deactivated and the engine load is released, the engine speed increases rapidly and becomes higher than high idle (so-called overrun), and then returns to the vicinity of high idle and stabilizes (time t _{2 to} t _3). ). In addition, at times t ₄ , t ₅ , and t ₆ , the cases where the engine speed is relatively high in the overrun are shown.

The engine control device 17 is set and stored with a first threshold value N _A and a second threshold value N _B (where N _A > N _B ) related to the engine speed, and in response to a detection signal from the speed sensor 15. performs predetermined calculation processing, it is determined whether the engine speed is first whether the threshold value N _a above, or the first and smaller than the threshold value N _a of the second threshold value N _B above. Then, for example, when the engine speed is the first threshold value N _A or more (time t _6), and controls so as to stop the engine (i.e. engine speed = 0), for example, the engine speed is the first threshold value N If and less than _a is a second threshold value N _B above (time t _5), so as to control the engine speed to low idle (predetermined no-load minimum speed). In these cases, it may be controlled to light a lamp (not shown) for notifying abnormality of the engine speed.

Here, as a major feature of this embodiment, the data recording apparatus 21, the third threshold value N _C which is set lower than the higher the second threshold value N _B from the high idle is stored, from the speed sensor 15 detection signal to perform a predetermined calculation process, when the engine speed exceeds a third threshold value N _C (time _{t 4, t 5, t 6} ), the predetermined time from the state quantity data (e.g. engine speed the third threshold N _C engine speed for 6 minutes, etc.) configured between 1 minute and after exceeding the previous 5 minutes beyond the operation position of the throttle 14, temporal relationship actuation angle of the governor actuator 16 The data extracted in the above (so-called snapshot) is generated and stored.

  The generated snapshot is downloaded and transferred from the data recording device 21 to the portable terminal 24 via the serial communication 23 or transmitted via a satellite communication terminal (not shown) as shown in FIG. For example, it is output to a PC terminal 25 installed in an office or the like that manages the operating state of the excavator 1.

  In the above, the rotational speed sensor 15 constitutes rotational speed detection means for detecting the rotational speed of the engine mounted on the construction machine described in the claims, and the throttle 14 and the governor actuator 16 are the engine described in the claims. An injection state quantity detecting means for detecting a state quantity related to the fuel injection control is configured.

  Further, the engine control device 17 constitutes a first storage unit that stores a first threshold value related to the engine speed and a second threshold value set smaller than the first threshold value. Protection means that stops the engine when the detected value of the engine reaches the first threshold value, and further controls the engine speed to be lowered when the detected value from the engine speed detecting means reaches the second threshold value. Means are also configured.

  Further, the data recording device 21 constitutes a second storage unit that stores a third threshold value set smaller than the second threshold value, and the detection value from the rotation speed detection unit has reached the third threshold value. Control that sometimes generates a time-dependent relationship between the detection value from the rotation speed detection means and the detection value from the injection state quantity detection means, stores them in the second storage means, and outputs the display signal read from the second storage means Means are also configured. The PC terminal 25 constitutes display means for displaying a display signal output from the control means outside the construction machine.

  Next, the operation and effect of this embodiment will be described.

For example, when performing excavation work or the like, when the operator drives the engine of the hydraulic excavator 1 and inputs an instruction to input the maximum target rotational speed with the throttle 14, the engine control device 17 receives the command signal from the throttle 14 and the rotational speed sensor 15. A predetermined calculation process is performed in accordance with the detection signal, and the generated control signal is output to the governor actuator 16 to control the engine speed. The hydraulic actuators that are activated by the operation of the operator (specifically, the left and right traveling hydraulic motors, the turning hydraulic motor, the boom hydraulic cylinder 10, the arm hydraulic cylinder 11, and the bucket) When the hydraulic cylinder 12 or the like is switched to the stopped state, the engine load is released and the engine speed becomes higher than the high idle (so-called overrun, see FIG. 3 described above). At this time, the engine control unit 17, for example, When the engine speed reaches the first and smaller than the threshold value N _A of the second threshold value N _B, to control the engine speed to low idle, for example, the engine speed is first the reaches the threshold N _a engine is stopped.

Then, the data recording apparatus 21, when exceeding the third threshold value N _C where the engine speed detected by the speed sensor 15 is set lower than the second threshold value N _B, within a predetermined time period in (for example, about 6 minutes) A snapshot obtained by extracting the detected engine speed, the operation position of the throttle 14, the operating angle of the governor actuator 16, etc. with a temporal relationship is generated and stored, and the display signal of this snapshot is used as an operating state of the hydraulic excavator 1, for example. Are output to a PC terminal 25 installed in an office or the like that manages the information and displayed.

  In this way, in the present embodiment, for example, the correspondence relationship between the engine speed and the operating angle of the governor actuator 16 that changes depending on the working environment of the hydraulic excavator 1 can be obtained as a snapshot, and is acquired in the past. A comparison diagnosis with the snapshot can be made to determine whether or not there is an abnormality in the parts related to the fuel injection control of the engine. Therefore, it is possible to detect in advance an abnormality of a part related to engine fuel injection control.

In particular, the large excavator 1 is used for, for example, debris excavation work at a large work site, and is generally continuously operated in order to improve productivity. In this embodiment, since the engine speed is created to compare diagnose the snapshot even if does not reach the first threshold value N _A and the second threshold value N _B described above, the engine and the stop or low idle state Before it becomes, it is possible to detect abnormality of components related to engine fuel injection control. For this reason, interruption of debris excavation work by the hydraulic excavator can be reduced.

In the above-described embodiment, the snapshot generated and stored by the data recording device 21 has been described as an example of output and displayed on the PC terminal 25 installed outside the hydraulic excavator 1, but the present invention is not limited thereto. Absent. That is, instead of the PC terminal 25, for example, the snapshot may be output and displayed on the display 18 'in the cab 5. Also, in that case, for example, with the display control unit 19 'stores the threshold N _C of the third, performs predetermined calculation processing on the detection signal from the speed sensor 15, the engine speed is the third when exceeding the threshold value N _C, generate and store the snapshot may output the display signal to the display 18 '. In these cases, the same effect as described above can be obtained.

  In the above, a hydraulic excavator has been described as an example of a construction machine. However, the present invention is not limited to this, and can be applied to other construction machines such as a crawler crane and a wheel loader. Get.

It is a side view showing the whole structure of a large-sized hydraulic shovel as an example of the construction machine used as the application object of the engine state quantity detection apparatus of the construction machine of this invention. 1 is a circuit diagram illustrating an embodiment of an engine state quantity detection device for a construction machine according to the present invention together with a configuration of main parts of a related controller network. It is a characteristic view showing the fluctuation | variation of the engine speed controlled by the engine control apparatus which comprises one Embodiment of the engine state quantity detection apparatus of the construction machine of this invention.

Explanation of symbols

14 Throttle (injection state quantity detection means)
15 Rotational speed sensor (Rotational speed detection means)
16 Governor actuator (injection state quantity detection means)
17 Engine control device (first storage means, stop means, protection means)
18 'display (display means)
19 'display control device (second storage means, control means)
21 Data recording device (second storage means, control means)
25 PC terminal (display means)
N _A First threshold N _B Second threshold N _C Third threshold

Claims (6)

  A rotation speed detection means for detecting the rotation speed of an engine mounted on a construction machine; an injection state quantity detection means for detecting a state quantity relating to fuel injection control of the engine; a first threshold value relating to the rotation speed of the engine; A first storage unit storing a second threshold value set smaller than the first threshold value; a second storage unit storing a third threshold value set lower than the second threshold value; and the rotation Stop means for stopping the engine when a detection value from the number detection means reaches the first threshold value, and rotation speed of the engine when the detection value from the rotation speed detection means reaches the second threshold value The detection value from the rotation speed detection means and the detection value from the injection state quantity detection means over time when the detection value from the rotation speed detection means reaches the third threshold value. Before generating the relationship Stored in the second storage unit, the second outputs a display signal read from the storage unit controlling means and construction machine engine state quantity detecting apparatus characterized by comprising a.   2. The engine state quantity detection device for a construction machine according to claim 1, further comprising display means for displaying a display signal output from the control means outside the construction machine. apparatus.   2. The engine state quantity detection device for a construction machine according to claim 1, further comprising display means for displaying a display signal output by the control means in a cab of the construction machine. Detection device.   The number of revolutions of the engine mounted on the construction machine is detected by the number of revolutions detecting means, the state quantity related to the fuel injection control of the engine is detected by the injection state quantity detecting means, and the rotation of the engine stored in the first storage means Based on the first threshold relating to the number, the second threshold set smaller than the first threshold, and the third threshold set smaller than the second threshold stored in the second storage means, When the detection value from the rotation speed detection means reaches the first threshold value, the engine is stopped by the stop means, and when the detection value from the rotation speed detection means reaches the second threshold value, The rotational speed is controlled to be lower by the protection means, and when the detection value from the rotational speed detection means reaches the third threshold value, the detection value from the rotational speed detection means and the detection value from the injection state quantity detection means are obtained. Over time And it generates the engaging stored in said second storage means, the construction machine engine state quantity detecting method characterized by a display signal read from the second storage means to output by the control means.   5. The engine state quantity detection method for a construction machine according to claim 4, wherein the display signal output by the control means is displayed on a display means provided outside the construction machine. Method.   The engine state quantity detection method for a construction machine according to claim 4, wherein the display signal output by the control means is displayed on a display means provided in a cab of the construction machine. Detection method.

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