JP2002257623A - Apparatus for inspecting source generating abnormal sound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for inspecting a source generating an abnormal sound, which can specify a section in malfunction contributing the generation of an abnormal sound when the abnormal sound is generated in a machine equipment. SOLUTION: The system is composed of a plurality of vibration detecting devices which are disposed on a machine equipment generating an abnormal sound, a memory means which stores detected signals representing the abnormal sound and vibration detected by the plurality of detecting devices in the order of arrival of the signals, a judging means which judges the source generating the abnormal sound in the machine equipment according to the order of arrival of the detected signals representing the abnormal sound and vibration stored in the memory means. The system is also composes of a plurality of vibration detecting devices which are disposed on an internal combustion engine having a plurality of cylinders and generating an abnormal sound, a memory means which stores detected signals representing the abnormal sound and vibration detected by the plurality of detecting devices in the order of arrival of the signals, a comparing means which compares the detection timing of the detected signals representing the abnormal sound and vibration detected by the plurality of detecting devices and an operational period of each cylinder in the internal combustion engine. Thereby, the source generating an abnormal sound can be specified in the internal combustion engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting an abnormal portion of a mechanical device from abnormal noise generated by the mechanical device when a malfunction occurs in the mechanical device.

[0002]

2. Description of the Related Art When an abnormal noise is emitted from a mechanical device, it is generally considered that there is a defect in a portion where the abnormal noise is heard most. Therefore, the area near the place where the abnormal sound is heard loudly will be investigated.In practice, however, the place where the abnormal sound is heard loudly does not always match the place where the malfunction that causes the abnormal noise vibration occurs. Therefore, it is very difficult to find a defective part.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention provides an apparatus for investigating an abnormal sound source that can identify a defective portion that causes abnormal noise when a mechanical device generates abnormal noise. That is the task.

[0004]

According to a first aspect of the present invention, there is provided an apparatus for generating abnormal noise, comprising a plurality of vibration detecting devices, wherein the abnormal vibration detected by the plurality of vibration detecting devices is provided. Storage means for storing the detection signals in the order of arrival, and determination means for determining the noise generation source of the mechanical device from the arrival order of the detection signal of the abnormal vibration stored in the storage means.

According to a second aspect of the present invention, an internal combustion engine having a plurality of cylinders and generating abnormal noise is provided with a plurality of vibration detecting devices, and a detection signal of abnormal noise detected from the plurality of vibration detecting devices arrives. Storage means for sequentially storing, and comparing means for comparing the detection timing of the detection signal of the abnormal noise detected by the vibration detection device with the operation cycle of each cylinder of the internal combustion engine, The sound source can be specified.

[0006]

FIG. 1 is a schematic diagram of an abnormal sound source investigating apparatus 100 according to the first or second aspect of the present invention.
In FIG. 1, the abnormal sound source investigating device 100 investigates a mechanical device including the internal combustion engine 1 and the generator 2.

[0007] The internal combustion engine 1 is a four-cycle engine having first to eighth eight cylinders. The drive shaft 4 of the internal combustion engine 1 and the drive shaft 21 of the generator 2 are connected by a coupling 3 so that the power of the internal combustion engine 1 is transmitted to the generator 2 side.

The cylinders are arranged in the order shown in FIG. 1 (in order from the left, first, fourth, seventh, sixth, eighth, fifth, second and third). Vibration detectors (accelerometers) 8 to 10 are mounted on portions of the side wall near the fourth cylinder, the sixth cylinder, and the third cylinder of the engine 1 at the same height as the drive shaft 4. The vibration detectors 8 to 10 are connected to the memory (storage device) 5 through signal lines 15 to 17 provided with charge amplifiers 25 to 29 in the middle, and the signals detected by the vibration detectors 8 to 10 are Stored in the memory 5.

The vibration detectors 8 to 10 generate charges corresponding to the magnitude of the detected vibration, and charge amplifiers 25 to 27 provided in the middle of the signal lines 15 to 17 convert the charges into voltages. This voltage value is stored in the memory 5.

Further, vibration detectors 11 and 12 provided with charge amplifiers 28 and 29 are mounted on the side wall at the same height as the drive shaft 21 of the generator 2. This vibration detector 1
The signals detected at 1 and 12 are also transmitted to the memory 5 via the signal lines 18 and 19.

The memory 5 stores the signals detected by the vibration detectors 8 to 12 in the order of arrival. The memory 5 is connected to the CPU 6 (determination means) by a signal line 13.
The CPU 6 determines from which of the vibration detectors abnormal vibration has occurred near the arrival order and arrival time difference of the detection signals stored in the memory 5.

A vibration pattern of the internal combustion engine 1 and the generator 2 during normal operation (including at start-up and steady-state operation) is stored in the operation map storage memory 20 in advance. CPU
6 (comparing means) compares the vibration pattern stored in the driving map storage memory 20 with the actually detected vibration, and detects a vibration deviating from the vibration pattern stored in the driving map storage memory 20. It is recognized as abnormal vibration and is output to an external output device (for example, a monitor or a recording sheet of a printer) via the signal line 14.

The CPU 6 determines which of the vibration detectors detects the vibration corresponding to the abnormal vibration at the earliest time, and performs maintenance mainly on the vicinity of the vibration detector. The faulty part of the generator 2) can be found.

For example, the vibration detected from the vibration detector 8 is the earliest, and the vibration detected next from the vibration detector 9 is 2
If it is the earliest, it is considered that the cylinder in which the failure or malfunction has occurred is any of the first, fourth, or seventh cylinder.

FIG. 2 is a graph showing the opening and closing timing of the intake valve and the exhaust valve of each cylinder. Since the internal combustion engine 1 is an eight-cylinder four-cycle engine, combustion is performed at a crank angle of 720 degrees. Each cylinder has a phase difference of 90 degrees, and the phases of intake and exhaust are also 90 degrees out of phase.

In one cycle of 720 degrees, a signal is transmitted in 360-degree units by the photoelectric angle detector 22 (adjusted so as to transmit a signal at the position of the piston top), and further, an in-cylinder pressure detector (shown in the figure). ) Can be measured by detecting the in-cylinder pressure. The CPU 6 grasps the operating state of each of the first to eighth cylinders, compares it with the operation map stored in the operation map storage memory 20, and performs normal operation of the vibration detected by each of the vibration detectors 8 to 12. Thus, the vibration caused by the above and the vibration deviating from the driving map can be distinguished.

FIG. 2 compares the detected abnormal vibration with the operation map of the internal combustion engine 1 on the same time axis. At the time when the abnormal vibration is detected, the exhaust valve of the first cylinder closes. This corresponds to the timing, and it is possible to find a possibility that a malfunction has occurred in the first cylinder (particularly, the clearance between the exhaust valve and the piston).

As described above, first, each of the vibration detectors 8 to 12
The rough fault location is determined from the order of arrival of the detection signals from the memory 5 in the memory 5, and the CPU 6 compares the operation map with the timing of occurrence of abnormal vibration, thereby narrowing down the fault location further and narrowing down the maintenance target. , It can be quickly restored to a normal operating state.

The vibration detectors 8 to 12 may be always installed in the internal combustion engine 1 or the generator 2, or may be installed after abnormal noise is generated. If it is installed at all times, it can respond immediately when abnormal noise occurs, and if it is installed after abnormal noise is generated, the number of noise generation sources equal to the number of existing or newly installed machinery There is no need to prepare the investigation device 100, which is economical.

[0020]

According to the first aspect of the present invention, there is provided a storage means for storing detection signals of abnormal vibrations detected from a plurality of vibration detection devices installed in a mechanical device in the order of arrival. Can be easily specified, and a normal operation state can be quickly restored by narrowing down the maintenance targets.

According to the second aspect of the present invention, since the comparison means for comparing the detection signal of the abnormal vibration detected from the vibration detecting device with the operation cycle of each cylinder of the internal combustion engine is provided, the abnormal noise generation source of the internal combustion engine is provided. Can be easily specified, and a normal operation state can be quickly restored by narrowing down the maintenance targets.

The sound emitted from the mechanical device is often emitted from a place where the sound is likely to be emitted (for example, a cooling vent). Although it is difficult to specify the source of the noise, according to the first or second aspect of the present invention, the source of the abnormal noise can be specified accurately without relying on experience or intuition.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an abnormal sound source investigating device according to the first or second aspect of the present invention.

FIG. 2 is a graph showing the opening / closing timing of an intake valve and an exhaust valve of each cylinder of an internal combustion engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Generator 3 Coupling 4 Drive shaft 5 Memory (storage means) 6 CPU (determination means, comparison means) 7 Monitor (output device) 8-12 Vibration detector (vibration detection device) 13-19 (signal line 20) Operation map storage memory 21 Drive shaft 25-29 Charge amplifier 100 Abnormal sound source investigation device

Claims (2)

[Claims] 1. A mechanical device that emits abnormal noise includes a plurality of vibration detecting devices, and storage means for storing detection signals of abnormal vibration detected from the plurality of vibration detecting devices in the order of arrival,
An abnormal sound source investigating device characterized by comprising a judging means for judging an abnormal sound generation source of the mechanical device from an arrival order of the abnormal vibration detection signal stored in the storage means. 2. An internal combustion engine having a plurality of cylinders that emits abnormal noise includes a plurality of vibration detecting devices, and storage means for storing detection signals of abnormal noise detected from the plurality of vibration detecting devices in the order of arrival. A comparison unit that compares a detection timing of a detection signal of the abnormal vibration detected by the vibration detection device with an operation cycle of each cylinder of the internal combustion engine, so that a noise generation source of the internal combustion engine can be specified. An abnormal sound source investigation device characterized by the following.