JP2003065098A - Engine performance diagnostics system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine performance diagnostics system capable of accurately diagnosing engine performance and accurately determining aging of engine performance and whether or not it is necessary to overhaul the engine. SOLUTION: An engine 11 is provided with an engine oil pressure sensor 12 for measuring an engine oil pressure and a boost pressure sensor 13 for measuring a boost pressure. Through a diagnostics mode, a controller 16 on a machine side automatically sets engine load conditions and an engine speed. The controller 16 also stores automatically readings of the engine oil pressure and boost pressure measured with the engine oil pressure sensor 12 and the boost pressure sensor 13. Changes with time in the measurement data of engine oil pressure and boost pressure stored in the controller 16 are displayed on a monitor 33. The engine performance is diagnosed and necessity of overhaul is determined by studying the data displayed on the monitor 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine performance diagnosis system for diagnosing engine performance based on accumulated measurement data.

[0002]

2. Description of the Related Art Conventionally, regarding an engine mounted on a work machine such as a hydraulic excavator (hereinafter, simply referred to as "machine"), a dealer mechanic needs a measuring instrument to obtain information on a physical quantity related to engine performance. Installation,
Measurements are performed by setting the engine rotation speed or moving the operating lever to relieve the engine or machine so that the engine or machine has a specific load condition.

Further, these records are also left as maintenance records, and past records are not systematically stored.

Further, since the measurement itself is also troublesome, it is not carried out unless it is particularly necessary, periodic measurement data cannot be obtained, and it is not possible to organize it as time-dependent change information.

[0005]

Therefore, conventionally, the performance of the engine could not be accurately diagnosed, and it was not possible to accurately determine the change over time of the engine performance or the necessity of overhaul.

The present invention has been made in view of the above circumstances, and provides an engine performance diagnostic system capable of accurately diagnosing the performance of an engine and accurately determining the temporal change of engine performance and the necessity of overhaul. That is the purpose.

[0007]

According to a first aspect of the present invention, a sensor for measuring a physical quantity related to engine performance, an engine load condition and an engine speed are automatically set to a constant value in a diagnostic mode. An engine performance diagnosis system including a controller that automatically stores a physical quantity related to engine performance measured by a sensor, and a monitor that displays a temporal change of a physical quantity related to engine performance stored in the controller. Although the engine performance varies depending on the load condition and the engine rotation speed, the controller automatically sets the test conditions to be constant each time, so that highly accurate engine performance diagnosis can be facilitated. Furthermore, even if the measurement data varies depending on the engine or machine, the engine performance of the same machine changes with time by storing and accumulating measurement data of physical quantities related to engine performance measured by sensors from the time of new vehicle. Can be accurately grasped, and the necessity of overhaul can be accurately determined. In addition, since the change over time of the measurement data of the physical quantity related to the engine performance is displayed on the monitor, the engine performance diagnosis can be performed on the spot where the data is measured.

According to a second aspect of the present invention, in the engine performance diagnosis system according to the first aspect, the physical quantity related to the engine performance is at least one of the engine oil pressure and the supply pressure, and the sensor measures the engine oil pressure. An engine performance diagnostic system that is at least one of an engine oil pressure sensor and an air pressure sensor that measures the air pressure. The engine oil pressure and the air pressure can be easily measured over time, and the engine performance can be improved according to deterioration of the engine performance. Since changes with time of these physical quantities appear, the degree of deterioration of engine performance can be easily determined by monitoring the changes with time of these physical quantities.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the embodiment shown in FIGS.

FIG. 1 shows a system configuration of an engine performance deterioration detection system for a hydraulic excavator, in which an engine main gallery hydraulic pressure (hereinafter, this hydraulic pressure is simply referred to as "engine hydraulic pressure") is shown in the engine 11 as a physical quantity related to engine performance. An engine oil pressure sensor 12 as a sensor for measuring, an air pressure sensor 13 as a sensor for measuring an air pressure as a physical quantity related to engine performance,
An engine rotation speed sensor 14 for measuring an engine rotation speed (hereinafter, the rotation speed is referred to as “rotation speed”) is provided.

Each sensor information measured by the engine oil pressure sensor 12, the air pressure sensor 13, and the engine speed sensor 14 is stored in the engine controller 15 as a controller for controlling the engine, or this engine controller 15 Is stored in the machine side controller 16 as a controller for machine operation control.

The engine controller 15 and the machine side controller 16 each include a central processing unit (so-called CPU) and a storage device (various memories).

A variable displacement hydraulic pump 21 as an engine load is connected to the engine 11. The discharge pipe line 22 of the hydraulic pump 21 is connected to a control valve 23, and the control valve 23 controls the direction and flow rate of the pump discharge oil to supply it to the hydraulic actuator 24.

When the hydraulic actuator 24 is, for example, a turning hydraulic motor that turns and drives an upper swing body of a hydraulic excavator, a turning brake is applied to the turning hydraulic motor.
25 are provided.

A relief valve 26 for maintaining the actuator working oil pressure at a set pressure is provided between the two passages for supplying working oil to the hydraulic actuator 24.

The discharge line 22 of the hydraulic pump 21 is provided with a pump discharge pressure sensor 27 for measuring the pump discharge pressure, and the capacity variable means 28 such as a swash plate of the hydraulic pump 21 is operated. A pump flow rate control pressure sensor 30 for measuring the pump flow rate control pressure is provided in the pipeline that supplies the pump flow rate control pressure to the actuator 29.

The engine speed depends on the engine controller
It is controlled by the electronic governor 31 and the fuel injection pump 32 by 15 and measured by the engine speed sensor 14.

The machine side controller 16 automatically sets the engine load condition and the engine speed in the automatic diagnosis mode to be constant, and measures the engine speed measured by the engine speed sensor 14 and the pump discharge pressure sensor 27. The pump discharge pressure, the pump flow control pressure measured by the pump flow control pressure sensor 30, the engine oil pressure measured by the engine oil pressure sensor 12, and the air pressure measured by the air pressure sensor 13 are automatically stored respectively. It has a function.

A monitor 33 is connected to the machine-side controller 16. The monitor 33 includes a keypad section 34 for inputting an automatic diagnosis mode, setting conditions and the like to the machine side controller 16 by button operation, and a change with time of measurement data stored in the machine side controller 16 such as engine oil pressure and supply pressure. Display unit that displays numerical values, etc. 35
And have.

An electric joystick 36 is connected to the machine-side controller 16. The electric joystick 36 is an operating lever for inputting the mechanical operation of the hydraulic excavator, and the electric signal output from the electric joystick 36 is arithmetically processed in the machine-side controller 16 to generate an electric signal such as an electromagnetic proportional valve. The oil pressure inputted to the oil converting means 37 and outputted from the electric oil converting means 37 is used as pilot pressure to pilot-control the control valve 23.

The machine-side controller 16 includes a communication tool (ET) by a personal computer 38.
Can be connected, so that the machine side controller 16
Make it easy for key operators to share the information stored inside.

Next, the operation of this embodiment will be described.

The engine oil pressure and the air pressure, which represent the soundness of the engine performance, vary from engine to engine even when a new vehicle is shipped, but the test conditions (that is, engine load condition and engine speed) are constant in one engine. By taking data periodically by using the above, it is possible to obtain powerful data that can sufficiently determine the change status over time and the necessity of overhaul.

Therefore, these data are recorded on the engine controller 15 or the machine side controller 16 by a simple operation and used as a basis for preliminary diagnosis and failure diagnosis of the engine 11.

At this time, the engine 11 becomes an electronic control system using an electronic governor 31, etc., and the engine hydraulic pressure and air supply pressure are data-managed by the engine controller 15 or the machine side controller 16. Further, the electric joystick 36 is used to make the engine 11 Since the environment in which the load can be controlled has been created, the machine side controller 16 can be automatically operated by a service person such as a hydraulic excavator performing automatic inspection operations at regular intervals such as when replacing the filter as shown below. The test conditions are set, the engine oil pressure and the air pressure are automatically measured, and the current measurement data is displayed on the display unit 35 of the monitor 33 in comparison with the past measurement data.

That is, in such engine performance deterioration detection / diagnosis work, in order to make appropriate diagnosis, the engine load condition and the engine speed are automatically set as test conditions.

The measurement data includes data representing the state of the machine at the time of measurement (engine speed, pump discharge pressure, pump flow control pressure) and data representing the state of the engine 11 (engine oil pressure, air supply pressure). Is recorded in the machine-side controller 16 or the engine controller 15 together with the machine-side usage time information, which is useful for detection of engine performance deterioration.

Next, a specific example of this engine performance deterioration detection work will be described with reference to the flow chart shown in FIG.

(Step 1) The above-mentioned engine performance deterioration detection work is carried out in the form of calibration.
500 hours, 1000 hours, 2 when a new vehicle is shipped before the machine is shipped
It will be carried out by a service person at the time of regular inspection such as 000 hours.

(Step 2) When carrying out this engine performance deterioration detection work, the service man operates the button of the keypad section 34 of the monitor 33 to enter the automatic diagnosis mode.

(Step 3) The machine side controller 16
The fuel injection pump 32 is automatically controlled through the electronic governor 31.
Set the engine speed to maximum speed.

(Step 4) The machine side controller 16
The hydraulic circuit (not shown) of the swing brake 25 is controlled to activate the swing brake 25, and even if the electric joystick 36 is not operated, a lever operation signal is output to the electro-hydraulic conversion means 37 to control the control valve 23. When opened, the relief valve 26 is automatically operated to perform a relief operation so that the hydraulic pump 21 satisfies a certain engine load condition.
Automatically set test conditions. That is, a constant load is applied to the engine 11 by controlling the pump discharge pressure and the pump discharge flow rate of the hydraulic pump 21 so as to be in a constant load state during engine performance diagnosis together with the engine speed.

(Step 5) Obtain measurement data. The measurement data includes an engine speed, a pump discharge pressure, a pump flow control pressure, which represents the state of the machine at the time of measurement, and an engine oil pressure and a supply pressure, which represent the state of the engine 11.

(Steps 6 and 7) When the measurement is completed, the measured data is stored and saved in the memory device of the machine side controller 16 or the engine controller 15.

(Step 8) The present measurement data is displayed on the display unit 35 of the monitor 33 at the same time together with the new vehicle shipment and past measurement data. Whether or not the error between the current measurement value and the past measurement value is within the allowable range may be displayed at the same time as the diagnosis result.

The engine performance is diagnosed by observing the display on the display unit 35 of these monitors 33, and the necessity of overhaul is determined.

The measurement data stored in the machine-side controller 16 can be retrieved and used by a machine administrator or the like as needed by a communication tool of the personal computer 38.

Next, the effects of this embodiment will be listed.

Although the engine performance varies depending on the engine load condition and the engine speed, the machine side controller 16 automatically sets the engine load condition and the engine speed constant every time, so that the engine performance diagnosis accuracy is improved.

Even if the measured data value varies depending on the engine 11 or the machine, the engine 11 of the same machine can store and store the measured data from the time of new vehicle, so that the change (deterioration) of the engine performance can be grasped and the overtime can be obtained. You can objectively judge the necessity of a hole.

Since the measurement data showing the change over time is displayed on the monitor 33 of the work machine, it can be used for engine performance diagnosis on the spot where the measurement work is performed.

With respect to the engine oil pressure and the supply air pressure, these changes over time can be easily measured, and changes over time of these physical quantities appear as the engine performance deteriorates. Therefore, by monitoring changes over time of these physical quantities, the engine The degree of performance degradation can be easily determined.

As described above, the diagnostic accuracy can be improved by the data comparison and examination by automatically setting the test conditions and storing the measurement data.

[0044]

According to the first aspect of the present invention, the engine performance varies depending on the engine load condition and the engine rotation speed. However, the controller automatically sets these test conditions to be constant each time, so that high accuracy is achieved. Easily diagnose engine performance. Furthermore, even if the measurement data varies depending on the engine or machine, the engine performance of the same machine changes with time by storing and accumulating measurement data of physical quantities related to engine performance measured by sensors from the time of new vehicle. Can be accurately grasped, and the necessity of overhaul can be accurately determined. In addition, since the change over time of the measurement data of the physical quantity related to the engine performance is displayed on the monitor, the engine performance diagnosis can be performed on the spot where the data is measured.

According to the second aspect of the present invention, the engine oil pressure and the supply air pressure can be easily measured with respect to their changes with time, and these physical values also show changes with time as the engine performance deteriorates. The degree of deterioration of engine performance can be easily determined by observing the change over time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an engine performance diagnosis system according to the present invention.

FIG. 2 is a flowchart showing a procedure for implementing the above system.

[Explanation of symbols]

11 engine 12 Engine oil pressure sensor as sensor 13 Air pressure sensor as sensor 16 Machine side controller as controller 33 monitor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI theme code (reference) G01M 15/00 G01M 15/00 Z (72) Inventor Hideyuki Kawasaki 4-10-1 Yoga, Setagaya-ku, Tokyo New Caterpillar Mitsubishi Corp. (72) Inventor Jun Tanaka 4-10-1 Yoga, Setagaya-ku, Tokyo F-term (reference) 2F055 AA21 BB20 CC60 DD20 EE40 FF45 GG03 2G087 BB01 DD11 EE23 3G084 inside New Caterpillar Mitsubishi Corp. AA07 BA01 DA00 DA22 FA00 FA11 FA12 FA33 3G093 AA08 AA10 BA00 BA16 BA24 DA01 DA02 DA03 DB22 EA01 EC02 EC04

Claims (2)

[Claims] 1. A sensor for measuring a physical quantity related to engine performance, an engine load condition and an engine speed are automatically set to a constant value in a diagnostic mode, and a physical quantity related to engine performance measured by the sensor is automatically set. An engine performance diagnosis system, comprising: a controller for storing the physical quantity stored in the controller; and a monitor for displaying a temporal change in a physical quantity related to the engine performance stored in the controller. 2. A physical quantity relating to engine performance is at least one of engine oil pressure and air pressure, and a sensor is at least one of an engine oil pressure sensor for measuring engine oil pressure and an air pressure sensor for measuring air pressure. The engine performance diagnosis system according to claim 1, wherein: