JPS60164611A - Exhaust valve monitor for internal-combustion engine - Google Patents

Abstract

PURPOSE:To monitor an actuating state of an exhaust valve, by installing a distance sensor in an exhaust valve motion system, and making the output into analog-to-digital conversion, while inputting the signal into a computer together with a crank angle signal for comparing it with the reference value. CONSTITUTION:Contact type or contactless type distance sensors 4 and 3 are installed in an exhaust valve 1 and, after each output of sensors 4 and 3 is made into analog-to-digital conversion by a converter 11. A signal out of a crank angle sensor 6 is also inputted into the computer 11. With these signals, those of valve lift, on-off valve timing, valve opening duration, valve seating speed, etc., in relation to a crank angle are all processed and compared with the reference value. With this constitution, an actuating state of the exhaust valve is outputted to an output unit 10, thus trouble or the like in the exhaust valve is monitored.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in internal combustion engines, and more particularly to a device for monitoring the operating state of an exhaust valve in a diesel engine.

[Prior art and problems] A diesel engine compresses air with a piston in a cylinder, injects fuel into the high-pressure, high-temperature air and burns it, and extracts that energy as mechanical energy. The combustion chamber formed at the top of the cylinder is exposed to high-temperature, high-pressure combustion gas and must withstand harsh conditions. In particular, under such conditions, the exhaust valve needs to perform operations such as closing the exhaust path and discharging high-temperature exhaust gas into the exhaust pipe in a timely and appropriate manner.

In this way, exhaust valves must operate under severe conditions, so in large and medium-sized engines such as uni-flow marine diesel engines that have exhaust valves, accidents such as exhaust valve damage and sticking occur. Likely to happen.

As described above, the exhaust valve is a weak point in the reliability of the engine, and from the viewpoint of engine maintenance, there is a real desire to be able to constantly monitor the condition of the exhaust valve during operation.

Therefore, as shown in Fig. 1, in some cases a proximity switch 2 is installed to check the lift of the exhaust valve 1. period,
It was not possible to learn about factors that affect engine performance, such as the speed at which the valve is seated, or the lifespan of the exhaust valve itself.

Furthermore, if an abnormality occurs in the valve mechanism, it is necessary to detect it early and take countermeasures, but there is no answer to this question.

[Purpose of the Invention] Therefore, the present invention constantly monitors the condition of the exhaust valve and its valve mechanism, which have a large impact on engine performance and reliability, operates under line-carrying conditions, and detects abnormalities. The purpose of the present invention is to detect and notify the occurrence of a malfunction in advance or at an early stage, so that appropriate countermeasures can be taken.

[Structure of the Invention] To achieve this object, the present invention provides a clearance distance sensor that is installed in an exhaust valve train system to detect the movement of the exhaust valve, and that converts an analog signal from the clearance distance sensor into a digital signal. An A/D converter, a crank angle sensor that detects the crank angle of the engine, and input signals from the crank angle sensor and the A/D converter to determine valve lift, valve opening/closing timing, valve opening period, and valve seating speed. The present invention is characterized in that it is an exhaust valve operating state monitoring device for an internal combustion engine, which comprises a computer that calculates the calculation result, and an output device that outputs the calculation result.

[Embodiments of the invention] The present invention will be described in detail below with reference to the embodiment shown in FIG.

The exhaust valve 1 provided in the cylinder head of the diesel engine 5 is required to operate reliably to discharge exhaust gas at set times and completely close the exhaust hole at other times. The movement of the exhaust valve l is determined by a non-contact gap distance measuring device 3, such as one that uses magnetism, electric capacitance, or sound waves, or by a device 4 that detects the displacement of the lift with a contact lever, etc. A valve clearance distance sensor is installed to detect and output an analog electrical signal such as voltage.

This signal is converted into a digital signal via the A/D converter 8, and is converted into a digital signal by the computer 11 (CPU 7 and arithmetic unit 9).
) is entered.

On the other hand, the instantaneous crank angle of the engine 5 is detected by a crank angle sensor 6, and its output signal is input to the computer 11.

The computer 11° processes the input signal from the exhaust valve clearance distance sensor 3 or 4 based on the input signal from the crank angle sensor 6, that is, the crank angle, and calculates the valve lift, valve opening/closing timing, valve opening period, and valve timing. Calculate the seating speed of the exhaust valve, or the pressure of each part if hydraulic pressure is used to drive the exhaust valve, and compare these values with predetermined values stored in the computer's memory. It is determined whether these values are within the allowable range, and if they are not within the allowable range, the contents are
T, output to an output device 10 such as a printer or an XY plotter.

The data displayed on the output device 10 allows the engine operator to know whether the operating state of the exhaust valve is good or bad. Further, if the computer determines that there is an abnormality, it is also possible to automatically send a notification means such as an alarm lamp or a buzzer.

Operators can detect abnormalities in the exhaust valve at an early stage, so
In such a case, necessary measures such as reducing the engine output, stopping the engine, or repairing the engine can be taken to prevent accidents such as a stuck exhaust valve.

Of course, this device can be applied to air supply valves in exactly the same way to obtain the same effect.

[Effects of the Invention] As explained in detail above, according to the present invention, since the engine must operate under severe conditions, failures are likely to occur, which greatly affects the performance and reliability of the engine. The operating state of the exhaust valve can be constantly monitored during operation. That is, it is possible to know numerical values that are processed by a computer and compared with reference values regarding the crank angle, valve lift, valve opening/closing timing, valve opening period, valve seating speed, etc. Therefore, exhaust valve malfunctions, stains, etc. can be detected in advance, and by taking the necessary measures, the engine can be operated in optimal conditions, and accidents such as exhaust valve stains can be prevented. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional exhaust valve operation detection device, and FIG. 2 is an explanatory diagram of an exhaust valve operation state monitoring device for an internal combustion engine according to the present invention. In the figure, 1 is an exhaust valve, 2 is a proximity switch, 3 is a non-contact type clearance distance sensor, 4 is a contact type clearance distance sensor,
5 is the engine, 6 is the crank angle sensor, 7 is the CPU, 8
is an A/D converter, 9 is an arithmetic device, 10 is an output device, 11
is a computer. Applicant Mitsubishi Heavy Industries, Ltd. Representative Patent Attorney Akira Sakama Patent Attorney Kitanishi Patent Attorney Shinpo Ishikawa Patent Attorney Yoshi Saigo Patent Attorney Yukio Harada Figure 1

Claims (1)

[Claims] A clearance distance sensor installed in the exhaust valve system to detect the movement of the exhaust valve, an A/D converter that converts an analog signal from the clearance distance sensor into a digital signal, and a crank angle sensor that detects the engine crank angle. An exhaust valve monitoring device for an internal combustion engine, comprising: a computer that processes information on input signals from the crank angle sensor and the A/D converter; and an output device that outputs the processing results.