An engine bench test vibration monitoring and fault diagnosis system

Abstract

The application provides an engine bench test vibration monitoring and fault diagnosis system, comprising: a bench, a vibration sensor is arranged on each support leg of the bench respectively, for monitoring vibration in the z-axis direction; an engine, flywheel shell legs on both sides of the engine are installed on the bench through damping blocks, vibration sensors are arranged on the bottom of the engine in the transverse and longitudinal directions respectively, for monitoring vibration in the x-axis and y-axis directions; in response to vibration of different parts of the engine exceeding an alarm limit value or a shutdown limit value, vibration signals collected by the vibration sensors are used to perform multi-dimensional fault diagnosis, wherein, fault diagnosis evaluation is performed by five fault modes. The application can find engine vibration fault information and give troubleshooting suggestions, and experimenters can troubleshoot vibration alarms, thereby greatly reducing the waste of experimental resources and time caused by blind trial and error.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of engine bench test, and particularly relates to an engine bench test vibration monitoring and fault diagnosis system. BACKGROUND

[0002] When performing a bench engine test, vibration detection is a key measure to ensure that the engine and the dynamometer are running in a normal working condition. Through vibration detection, damage to equipment caused by excessive vibration can be effectively prevented, and the smooth progress of the test and the safety of the equipment can be ensured. Currently, a 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 for detecting the vibration of the engine in the x-axis, y-axis and z-axis directions.

[0003] Although the existing method can comprehensively detect the vibration of the engine in three dimensions, in the actual test process, when the vibration in a certain dimension exceeds the preset maximum limit value, the existing method cannot accurately reflect the specific reason for the vibration exceeding the limit. For example, when the vibration exceeds the limit, it cannot be directly judged whether it is caused by poor engine alignment, performance degradation of the shock block, mismatch of the tooling piece or other reasons, and usually a series of cumbersome steps are required to gradually troubleshoot the problem. Such troubleshooting process not only consumes time, but also may require multiple trial and error, resulting in low test efficiency and affecting the entire test progress. SUMMARY

[0004] Therefore, the application aims to provide an engine bench test vibration monitoring and fault diagnosis system to solve the problem that the existing troubleshooting method is not only time-consuming and laborious, but also may cause delay in the test progress and increase the test cost when performing an engine bench test.

[0005] To achieve the above-mentioned purpose, the technical solution of the application is as follows:

[0006] The application provides an engine bench test vibration monitoring and fault diagnosis system, comprising:

[0007] a bench, wherein each support leg of the bench is provided with a vibration sensor for monitoring the vibration in the z-axis direction;

[0008] an engine, wherein the flywheel shell legs on both sides of the engine are installed on the bench through shock blocks, and vibration sensors are arranged on the bottom of the engine in the transverse and longitudinal directions for monitoring the vibration in the x-axis and y-axis directions;

[0009] in response to the vibration of different parts of the engine exceeding the alarm limit value or the shutdown limit value, multi-dimensional fault diagnosis is performed according to the vibration signals collected by the vibration sensors, wherein the fault diagnosis is evaluated by five fault modes.

[0010] Further, four vibration sensors are arranged on the support legs of the test bench.

[0011] The bottom of the engine is provided with a fixed support, and two vibration sensors are arranged on the fixed support.

[0012] Further, the alarm limit is defined as 5mm / s, and the system triggers an alarm in response to the vibration displacement being greater than or equal to 5mm / s.

[0013] Further, the shutdown limit is defined as 7mm / s, and the system controls the transmitter to shut down in response to the vibration displacement being greater than or equal to 7mm / s.

[0014] Further, in response to being in fault mode one, the system diagnoses a performance decline of the damping block in response to any one of the four vibration sensors arranged on the support legs triggering an alarm or shutdown.

[0015] In response to being in fault mode two, the system diagnoses a global shift of the engine in response to any two of the four vibration sensors arranged on the support legs triggering an alarm or shutdown.

[0016] In response to being in fault mode three, the system diagnoses a counterweight measure of the engine in response to all of the four vibration sensors arranged on the support legs triggering an alarm or shutdown simultaneously.

[0017] Further, in response to being in fault mode four, the system diagnoses a mismatch of the engine tooling in response to any one of the two vibration sensors arranged on the fixed support triggering an alarm or shutdown.

[0018] Further, in response to being in fault mode five, the system diagnoses a misalignment of the engine in response to both of the two vibration sensors arranged on the fixed support triggering an alarm or shutdown simultaneously.

[0019] Compared with the prior art, the engine test bench vibration monitoring and fault diagnosis system has the following beneficial effects:

[0020] The engine test bench vibration monitoring and fault diagnosis system can ultimately convert the mechanical vibration signals detected by the sensors into digital signals by building a new vibration monitoring system, and can find engine vibration fault information and give troubleshooting suggestions according to different signal combinations of the six sensors triggering an alarm or shutdown. The experimental personnel can troubleshoot the vibration alarm, greatly reducing the waste of experimental resources and time caused by blind trial and error. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The illustrations, together with their description, serve to explain the application without unduly

[0022] Figure 1 A schematic diagram of an engine test bench vibration monitoring and fault diagnosis system according to an embodiment of the present application;

[0023] Figure 2 A schematic diagram of five fault modes according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] To make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and the accompanying drawings.

[0025] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be understood as the common meanings understood by those skilled in the art to which the present application belongs. The terms "first", "second" and similar terms used in the embodiments of the present application do not represent any order, number or importance, but are only used to distinguish different components. The terms "include", "contain" and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms do not mean physical or mechanical connections, but can be logical or electrical connections, which include electrical connections, whether direct or indirect.

[0026] The terms "up", "down", "left", "right" and the like are only used to indicate relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0027] As described in the above background, when the engine test bench test is performed, if the vibration exceeds the limit, the existing vibration detection system can only issue an alarm or stop, but cannot clearly indicate the specific reason for the vibration exceeding the limit. This makes the technical personnel have to adopt the trial and error method in the troubleshooting process, and check the engine centering condition, the performance of the shock absorbing block, the matching of the tooling piece and other potential factors one by one. This inefficient troubleshooting method not only consumes time and effort, but also may cause the test schedule to be delayed and increase the test cost.

[0028] To solve the above problems, as shown in Figure 1 The present embodiment provides an engine test bench vibration monitoring and fault diagnosis system, which comprises:

[0029] A test bench, wherein each support leg of the test bench is provided with a vibration sensor for monitoring the vibration in the z-axis direction;

[0030] The engine, the flywheel shell legs on both sides of the engine are installed on the rack through the damping blocks, and the vibration sensors are arranged in the transverse direction and the longitudinal direction at the bottom of the engine respectively for monitoring the vibration in the x-axis and y-axis directions;

[0031] In response to the vibration of different parts of the engine exceeding the alarm limit or the shutdown limit, the vibration signals collected by the vibration sensors are used for multi-dimensional fault diagnosis, wherein five fault modes are used for fault diagnosis evaluation.

[0032] The application provides an engine rack test vibration monitoring and fault diagnosis system. By building a new vibration monitoring system, the mechanical vibration signals detected by the sensors can be finally converted into digital signals. According to the signal combination of the triggering alarm or shutdown of the six sensors, the engine vibration fault information can be found and troubleshooting suggestions can be given. The experimental personnel can check the vibration alarm, which greatly reduces the waste of experimental resources and time caused by blind trial and error.

[0033] Specifically, in this embodiment, a new system for monitoring the vibration of the engine rack is built, which specifically includes six sensors for detecting the mechanical vibration of the rack and converting the mechanical vibration into electrical signals, a charge amplifier and a filter for amplifying the electrical signals and removing noise, and an analog-to-digital converter for converting the electrical signals into digital signals for computer recognition. The visualized result of the signals detected by the sensors on the computer is the displacement of the engine in a certain dimension per second.

[0034] The specific arrangement of the sensors is shown in the figure. One vibration sensor is arranged on each of the four supporting legs in front left, front right, rear left and rear right of the rack and numbered as ①, ②, ③ and ④, respectively, to detect the vibration in the z-axis direction. A fixed support is installed at the bottom of the engine, and a vibration sensor is arranged in the transverse and longitudinal directions, numbered as ⑤ and ⑥, respectively, to detect the vibration in the x-axis and y-axis directions.

[0035] In addition, when the displacement is ≥5mm / s, the system alarms; when the displacement is ≥7mm / s, the system forces the engine to stop immediately.

[0036] As shown in Figure 2 Five fault modes are defined: when any one of the ①, ②, ③ and ④ sensors triggers an alarm or shutdown, it is defined as fault mode one; when any one of the ①② / ③④ / ①③ / ②④ sensor signals triggers an alarm or shutdown, it is defined as fault mode two; when the ①, ②, ③ and ④ sensor signals trigger an alarm or shutdown together, it is defined as fault mode three; when any one of the ⑤ or ⑥ sensor signals triggers an alarm or shutdown, it is defined as fault mode four; and when the ⑤ and ⑥ sensor signals trigger an alarm or shutdown together, it is defined as fault mode five.

[0037] Wherein, when the engine different parts of the vibration exceeds the alarm limit or shutdown limit, will be according to ①-⑥ different sensor signal combination to the experiment personnel put forward clear vibration troubleshooting method, the working principle of the embodiment is as follows:

[0038] Fault mode one, diesel engine shock absorber performance decline diagnosis: when ①, ②, ③, ④ any sensor signal triggers alarm or shutdown, it shows that only one support leg z axis direction vibration is too large at this time, so the maximum possibility of failure is the shock absorber connected to the support leg shock absorber performance decline.

[0039] Because the shock absorber is made of rubber material, so many times its internal crack is not easy to observe outside, so even if no obvious external damage to the shock absorber should be replaced in time.

[0040] Fault mode two, diesel engine overall deviation diagnosis: when ①② / ③④ / ①③ / ②④ sensor signal any group triggers alarm or shutdown, it shows that the diesel engine overall deviation to a certain direction at this time, at this time should focus on troubleshooting diesel engine support leg, the four support legs of diesel engine is the key to its stability, if the two support legs in a certain direction exist height inconsistency or installation uneven, will lead to the overall deviation of diesel engine in that direction.

[0041] Fault mode three, diesel engine counterweight measures diagnosis: when ①②③④ sensor signal alarm or shutdown together, it shows that the engine in the z axis vertical direction overall vibration is too large, at this time should check whether the engine and dynamometer are too concentrated on one side of the base. The spring under the diesel engine base has a large elastic modulus. If the test bench equipment is too concentrated on one side, it will cause the base to produce a kind of "seesaw" effect, and then cause the four sensors in the z axis direction of the diesel engine to alarm together.

[0042] Fault mode four, diesel engine tooling diagnosis: when ⑤ or ⑥ any sensor signal triggers alarm or shutdown, it shows that the engine vibration is too large in x axis or y axis. Because the z axis direction is not alarmed, so should first check the problem of tooling mismatch, such as gantry is too thin, flywheel connecting disc is damaged, etc.

[0043] Fault mode five, diesel engine misalignment diagnosis: when ⑤ and ⑥ sensor signal triggers alarm or shutdown together, it shows that the diesel engine vibration is too large in the plane composed of horizontal and vertical direction, at this time should first consider the misalignment of the diesel engine. The misalignment of the engine and the transmission or other connecting parts leads to the imbalance of the axial force, thereby causing the plane vibration. At this time, it needs to be recentered.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and 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 application, and they should be covered in the scope of the claims and the description of the present application.

[0045] The embodiments of the present application are intended to cover all such alternatives, modifications and variations as fall within the broad scope of the appended claims. Accordingly, any one or more of the above-described embodiments can be combined with any other embodiment, or variations of those embodiments, to provide other embodiments that fall within the scope of the present application.

Claims

1. An engine bench test vibration monitoring and fault diagnosis system, characterized in that, It comprises: a rack, each support leg of which is provided with a vibration sensor for monitoring vibration in the z-axis direction; an engine, flywheel housing legs of which are installed on the rack through damping blocks, and the bottom of which is provided with vibration sensors in the x-axis and y-axis directions for monitoring vibration in the x-axis and y-axis directions; in response to vibration of different parts of the engine exceeding the alarm limit or the shutdown limit, multi-dimensional fault diagnosis is performed according to the vibration signals collected by the vibration sensors, wherein fault diagnosis evaluation is performed by five fault modes; in response to fault mode one, if any of the four vibration sensors provided on the support leg triggers an alarm or shutdown, it is diagnosed that the damping block performance is degraded; in response to fault mode two, if any of the four vibration sensors provided on the support leg triggers an alarm or shutdown, it is diagnosed that the engine overall deviation is offset; in response to fault mode three, if the four vibration sensors provided on the support leg trigger an alarm or shutdown at the same time, it is diagnosed that the engine counterweight measure is taken; in response to fault mode four, if any of the two vibration sensors provided on the fixed support triggers an alarm or shutdown, it is diagnosed that the engine tooling piece is not matched; in response to fault mode five, if the two vibration sensors provided on the fixed support trigger an alarm or shutdown at the same time, it is diagnosed that the engine is poorly centered.

2. The engine rack test vibration monitoring and fault diagnosis system according to claim 1, characterized in that: four vibration sensors are installed on the support legs of the rack; a fixed support is installed on the bottom of the engine, and two vibration sensors are provided on the fixed support.

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

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

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