Vibration monitoring and fault diagnosis system for engine bench test

Abstract

The invention provides an engine bench test vibration monitoring and fault diagnosis system, comprising a bench, each support leg of which is provided with a vibration sensor used for monitoring vibration in a z-axis direction; flywheel shell legs on the two sides of the engine are installed on the rack through damping blocks, and vibration sensors are arranged at the bottom of the engine in the transverse direction and the longitudinal direction correspondingly and used for monitoring vibration in the x-axis direction and the y-axis direction. And in response to the fact that vibration of different parts of the engine exceeds an alarm limit value or a shutdown limit value, multi-dimensional fault diagnosis is carried out according to vibration signals collected by the vibration sensor, and fault diagnosis evaluation is carried out through five fault modes. According to the method, the engine vibration fault information can be found in a targeted manner, the troubleshooting suggestions can be given, an experimenter can troubleshoot the vibration alarm in a targeted manner, and the waste of experiment resources and time caused by blind trial and error is greatly reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of engine bench test, and in particular, relates to an engine bench test vibration monitoring and fault diagnosis system. Background Art

[0002] When conducting bench engine tests, vibration detection is a key measure to ensure that the engine and dynamometer operate under normal conditions. Vibration detection can effectively prevent equipment from being damaged by excessive vibration, ensuring the smooth progress of the test and the safety of the equipment. At present, the commonly used vibration measurement method is to install a square vibration sensor base on the dynamometer and place a sensor on each of the three orthogonal surfaces of the base to detect the vibration of the engine in the three directions of the x-axis, y-axis, and z-axis.

[0003] Although existing methods can comprehensively detect engine vibration in three dimensions, in actual testing, when the vibration in one dimension exceeds the preset maximum limit, existing methods cannot promptly and accurately reflect the specific cause of the vibration exceeding the limit. For example, when the vibration exceeds the limit, it is impossible to directly determine whether it is caused by poor engine alignment, degraded damping block performance, mismatched tooling parts, or other reasons. It is usually necessary to go through a series of tedious steps to gradually troubleshoot the problem. This troubleshooting process is not only time-consuming, but may also require multiple trial and error, resulting in low test efficiency and affecting the progress of the entire test. Summary of the invention

[0004] In view of this, the present application aims to propose an engine bench test vibration monitoring and fault diagnosis system to solve the problem that when conducting engine bench tests, the existing troubleshooting method is not only time-consuming and labor-intensive, but may also cause delays in test progress and increase test costs.

[0005] To achieve the above purpose, the technical solution of this application is implemented as follows: The present application provides an engine bench test vibration monitoring and fault diagnosis system, comprising: A platform, wherein each supporting leg of the platform is provided with a vibration sensor for monitoring vibration in the z-axis direction; An engine, wherein the flywheel housing legs on both sides of the engine are mounted on the platform through shock-absorbing blocks, and vibration sensors are arranged in the horizontal and vertical directions at the bottom of the engine to monitor the vibration in the x-axis and y-axis directions; In response to vibrations at different parts of the engine exceeding an alarm limit or a shutdown limit, a multi-dimensional fault diagnosis is performed based on vibration signals collected by the vibration sensor, wherein the fault diagnosis is evaluated based on five fault modes.

[0006] Further, four vibration sensors are installed on the support legs of the stand; A fixing bracket is installed at the bottom of the engine, and two vibration sensors are arranged on the fixing bracket.

[0007] Furthermore, the alarm limit is defined as 5 mm / s, and in response to the vibration displacement being greater than or equal to 5 mm / s, the system triggers an alarm.

[0008] Furthermore, the shutdown limit is defined as 7 mm / s. In response to the vibration displacement being greater than or equal to 7 mm / s, the system controls the transmitter to shut down.

[0009] Further, in response to failure mode 1, any one of the four vibration sensors provided on the supporting leg triggers an alarm or shuts down, then the diagnosis determines that the performance of the shock absorbing block is degraded; In response to the second fault mode, any two vibration sensors of the four vibration sensors provided on the support legs trigger an alarm or shut down, then the diagnosis determines that the engine integrity is offset; In response to failure mode three, the four vibration sensors provided on the supporting legs trigger an alarm or shut down simultaneously, and the engine balancing measures are determined through diagnosis.

[0010] Further, in response to failure mode four, if any one of the two vibration sensors provided on the fixed bracket triggers an alarm or shuts down, the diagnosis determines that the engine tooling does not match.

[0011] Further, in response to failure mode five, two vibration sensors arranged on the fixed bracket give out alarms or shut down at the same time, and the diagnosis determines that the engine is poorly aligned.

[0012] Compared with the prior art, the engine bench test vibration monitoring and fault diagnosis system described in this application has the following beneficial effects: The engine bench test vibration monitoring and fault diagnosis system described in the present application can ultimately convert the mechanical vibration signal detected by the sensor into a digital signal by building a new vibration monitoring system, and can specifically detect the engine vibration fault information and give troubleshooting suggestions based on the different signal combinations of six sensors that trigger alarms or shutdowns. Experimenters can conduct targeted troubleshooting of vibration alarms, greatly reducing the waste of experimental resources and time caused by blind trial and error. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0014] Figure 1 This is a schematic diagram of the structure of an engine bench test vibration monitoring and fault diagnosis system according to an embodiment of the present application; Figure 2 Schematic diagram of the five failure modes described in the embodiments of the present application. DETAILED DESCRIPTION

[0015] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0016] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The words "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprises" and other similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and other similar words are not limited to physical or mechanical connections, but can be

[0017] Including electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0018] As described in the background technology above, when conducting an engine bench test, if the vibration exceeds the limit, the existing vibration detection system can only issue an alarm or shut down, but cannot clearly point out the specific cause of the vibration exceeding the limit. This forces technicians to adopt a trial-and-error method during the troubleshooting process, checking multiple potential factors one by one, such as the engine alignment, the performance of the shock absorber, and the matching of the tooling parts. This inefficient troubleshooting method is not only time-consuming and labor-intensive, but may also cause delays in the test progress and increase the test cost.

[0019] To solve the above problems, Figure 1 As shown, this embodiment provides an engine bench test vibration monitoring and fault diagnosis system, including: The platform, each support leg of the platform is provided with a vibration sensor for monitoring the vibration in the z-axis direction; Engine, the flywheel housing legs on both sides of the engine are installed on the test bench through shock-absorbing blocks, and vibration sensors are arranged in the horizontal and vertical directions at the bottom of the engine to monitor the vibration in the x-axis and y-axis directions; In response to vibrations at different parts of the engine exceeding alarm limits or shutdown limits, multi-dimensional fault diagnosis is performed based on vibration signals collected by vibration sensors, wherein fault diagnosis evaluation is performed based on five fault modes.

[0020] The present application provides an engine bench test vibration monitoring and fault diagnosis system. By building a new vibration monitoring system, the mechanical vibration signal detected by the sensor can be ultimately converted into a digital signal. According to the different signal combinations of triggering alarms or shutdowns of six sensors, the engine vibration fault information can be detected and troubleshooting suggestions can be given. Experimenters can conduct targeted troubleshooting of vibration alarms, greatly reducing the waste of experimental resources and time caused by blind trial and error.

[0021] Specifically, in this embodiment, a new system for monitoring the vibration of the engine test bench is built, which includes six sensors for detecting the mechanical vibration of the test bench and converting the mechanical vibration into electrical signals, charge amplifiers and filters for amplifying the electrical signals and removing noise, and analog-to-digital converters for converting the electrical signals into digital signals for computer recognition. Finally, the signal detected by the sensor is visualized on the computer as the displacement of a certain dimension of the engine per second.

[0022] The specific arrangement of the sensors is shown in the figure. A vibration sensor is arranged on each of the four supporting legs of the test bench, namely the left front, right front, left rear and right rear legs, and they are numbered as sensors ①, ②, ③ and ④, to detect vibration in the z-axis direction. A fixed bracket is installed at the bottom of the engine, and a vibration sensor is arranged in the horizontal and vertical directions, respectively, numbered as sensors ⑤ and ⑥, to detect vibration in the x-axis and y-axis directions, respectively.

[0023] In addition, it is defined that when the displacement is ≥5mm / s, the system will alarm; when the displacement is ≥7mm / s, the system will immediately force the engine to shut down.

[0024] like Figure 2 As shown, five fault modes are defined: when any sensor signal from ①, ②, ③, and ④ triggers an alarm or shutdown, it is defined as fault mode 1; when any group of sensor signals from ①② / ③④ / ①③ / ②④ triggers an alarm or shutdown, it is defined as fault mode 2; when sensor signals from ①②③④ all alarm or shut down, it is defined as fault mode 3; when any sensor signal from ⑤ or ⑥ triggers an alarm or shutdown, it is defined as fault mode 4; when sensor signals from ⑤ and ⑥ trigger an alarm or shutdown together, it is defined as fault mode 5.

[0025] Among them, when the vibration of different parts of the engine exceeds the alarm limit or the shutdown limit, a clear vibration troubleshooting method will be proposed to the experimenter according to the different sensor signal combinations of ①-⑥. The working principle of this embodiment is as follows: Fault mode 1: Diagnosis of performance degradation of diesel engine shock absorber block: When any sensor signal of ①, ②, ③, ④ triggers an alarm or shutdown, it means that only one supporting leg has excessive vibration in the z-axis direction. Therefore, the most likely fault is that the shock absorbing performance of the shock absorber block connected to the supporting leg has deteriorated.

[0026] Because the shock absorbers are mostly made of rubber materials, cracks inside them are often not easy to observe from the outside. Therefore, even if no obvious external damage is observed on the shock absorbers, they should be replaced in time.

[0027] Fault mode 2: Diagnosis of overall displacement of diesel engine: When any of the sensor signals ①② / ③④ / ①③ / ②④ triggers an alarm or shutdown, it means that the diesel engine is displaced in a certain direction as a whole. At this time, the support legs of the diesel engine should be checked. The four support legs of the diesel engine are the key to its stability. If the two support legs in a certain direction are inconsistent in height or unevenly installed, the diesel engine will be displaced as a whole in that direction.

[0028] Fault mode three, diesel engine counterweight measures diagnosis: When the signals of ①②③④ sensors alarm or shut down together, it indicates that the overall vibration of the engine in the vertical direction of the z-axis is too large. At this time, it is necessary to check whether the engine and dynamometer are too concentrated on one side of the base. There is a spring with a large elastic modulus under the diesel engine base. If the test bench equipment is too concentrated on one side, the base will produce a "seesaw" effect, which will cause the four sensors in the z-axis direction of the diesel engine to alarm together.

[0029] Failure mode 4, diesel engine tooling diagnosis: When any sensor signal of ⑤ or ⑥ triggers an alarm or shuts down, it means that the engine vibrates too much in the x-axis or y-axis. Because there is no alarm in the z-axis direction, the tooling mismatch problem should be checked first, such as the gantry is too thin, the flywheel connection plate is damaged, etc.

[0030] Failure mode 5, poor diesel engine alignment diagnosis: When the signals of sensors ⑤ and ⑥ trigger an alarm or shutdown together, it means that the diesel engine vibrates too much in the horizontal and vertical planes. At this time, the diesel engine should be poorly aligned first. The alignment between the engine and the transmission or other connecting parts is not accurate, resulting in unbalanced axial force, which causes plane vibration. Realignment is required at this time.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0032] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. An engine bench test vibration monitoring and fault diagnosis system, characterized in that: include: A platform, wherein each supporting leg of the platform is provided with a vibration sensor for monitoring vibration in the z-axis direction; An engine, wherein the flywheel housing legs on both sides of the engine are mounted on the platform through shock-absorbing blocks, and vibration sensors are arranged in the horizontal and vertical directions at the bottom of the engine to monitor the vibration in the x-axis and y-axis directions; In response to vibrations at different parts of the engine exceeding an alarm limit or a shutdown limit, multi-dimensional fault diagnosis is performed based on vibration signals collected by the vibration sensor, wherein fault diagnosis evaluation is performed based on five fault modes.

2. The engine bench test vibration monitoring and fault diagnosis system according to claim 1, characterized in that: Four vibration sensors are installed on the supporting legs of the platform; A fixing bracket is installed at the bottom of the engine, and two vibration sensors are arranged on the fixing bracket.

3. The engine bench test vibration monitoring and fault diagnosis system according to claim 1, characterized in that: The alarm limit is defined as 5mm / s. In response to the vibration displacement being greater than or equal to 5mm / s, the system triggers an alarm.

4. The engine bench test vibration monitoring and fault diagnosis system according to claim 1, characterized in that: The shutdown limit is defined as 7 mm / s. In response to the vibration displacement being greater than or equal to 7 mm / s, the system controls the transmitter to shut down.

5. The engine bench test vibration monitoring and fault diagnosis system according to claim 1, characterized in that: In response to the failure mode 1, any of the four vibration sensors provided on the supporting leg triggers an alarm or shuts down, then the diagnosis determines that the performance of the shock absorbing block is degraded; In response to the second fault mode, any two vibration sensors of the four vibration sensors provided on the support legs trigger an alarm or shut down, then the diagnosis determines that the engine integrity is offset; In response to failure mode three, the four vibration sensors provided on the supporting legs trigger an alarm or shut down simultaneously, and the engine balancing measures are determined through diagnosis.

6. The engine bench test vibration monitoring and fault diagnosis system according to claim 1, characterized in that: In response to failure mode four, if any one of the two vibration sensors provided on the fixed bracket triggers an alarm or shuts down, the diagnosis determines that the engine tooling parts do not match.

7. The engine bench test vibration monitoring and fault diagnosis system according to claim 1, characterized in that: In response to failure mode five, the two vibration sensors arranged on the fixed bracket give out alarms or shut down at the same time, and the diagnosis determines that the engine is poorly aligned.

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