阅读说明：本技术 飞行器电缆组件热振联合绝缘性实时监测试验系统及方法 (Thermal-vibration combined insulation real-time monitoring test system and method for aircraft cable assembly ) 是由 李小婷 张衡 李乃田 王冶峰 李春祥 高勇 肖登红 洪苇江 于 2020-11-09 设计创作，主要内容包括：本发明提供了一种飞行器电缆组件热振联合绝缘性实时监测试验系统及方法,该系统包括安装平台、加热箱及加热箱控制装置、振动台及振动控制采集装置、温度数据采集装置、电缆绝缘测试装置；所述安装平台固定在振动台上,所述安装平台上设置试验件及温度传感器,所述加热箱底部开口罩住安装平台且开口与安装平台间填充柔性隔热材料,所述加热箱控制装置控制加热箱内温度及调整加热箱位置,所述振动控制采集装置采集振动台振动数据,所述温度数据采集装置加热箱内温度传感器数据,所述电缆绝缘测试装置与试验件伸出加热箱的一端电缆连接,实时监测试验件绝缘性。本发明可在严酷高温振动条件下对飞行器电缆组件的绝缘性能进行在线实时监测。(The invention provides a real-time monitoring and testing system and method for thermal vibration combined insulation of an aircraft cable assembly, wherein the system comprises an installation platform, a heating box and heating box control device, a vibration table and vibration control acquisition device, a temperature data acquisition device and a cable insulation testing device; the mounting platform is fixed on the shaking table, set up test piece and temperature sensor on the mounting platform, fill flexible thermal insulation material between mounting platform and opening and mounting platform is covered to heating cabinet bottom opening, temperature and adjustment heating cabinet position in the heating cabinet controlling means control heating cabinet, vibration control collection system gathers shaking table vibration data, temperature sensor data in the temperature data collection system heating cabinet, cable insulation testing arrangement and test piece stretch out the one end cable junction of heating cabinet, real-time supervision test piece insulating nature. The invention can carry out on-line real-time monitoring on the insulation performance of the aircraft cable assembly under the severe high-temperature vibration condition.)

1. A real-time monitoring and testing system for the thermal vibration and combined insulation of an aircraft cable assembly is characterized by comprising an installation platform, a heating box and heating box control device, a vibration table and vibration control acquisition device, a temperature data acquisition device and a cable insulation testing device; the mounting platform is fixed on the shaking table, set up test piece and temperature sensor on the mounting platform, fill flexible thermal insulation material between mounting platform and opening and mounting platform is covered to heating cabinet bottom opening, temperature and adjustment heating cabinet position in the heating cabinet controlling means control heating cabinet, vibration control collection system gathers shaking table vibration data, temperature sensor data in the heating cabinet is gathered to temperature data collection system, cable insulation testing arrangement and test piece stretch out the one end cable junction of heating cabinet, real-time supervision test piece insulating nature.

2. The system according to claim 1, wherein the test piece comprises a group of connected electric connectors, and a section of cable is carried at each of two ends of each electric connector, and one end of the cable extends out of the heating box and is subjected to insulation treatment by using a heat shrink tube, and the other end of the cable extends out of the heating box and is connected with a cable insulation testing device.

3. The aircraft cable assembly thermal-vibration combined insulation real-time monitoring test system according to claim 1, wherein a plurality of sleeves, clamping plates and clamping hoops for mounting test pieces are arranged on the upper surface of the mounting platform.

4. The aircraft cable assembly thermal vibration combined insulation real-time monitoring test system according to claim 1, wherein the non-examined section of the test piece positioned in the heating box is wrapped by a heat insulation layer, and the non-examined section positioned outside the heating box is fixed on the mounting platform by a fixing belt.

5. The aircraft cable assembly thermal vibration combined insulation real-time monitoring test system according to claim 1, wherein the vibration table is protected at the bottom of the mounting platform near a position connected with the vibration table in a water cooling mode.

6. A real-time monitoring and testing method for the thermal vibration combined insulation of an aircraft cable assembly is characterized in that the real-time monitoring and testing system for the thermal vibration combined insulation of the aircraft cable assembly as claimed in any one of claims 1-5 is adopted, and comprises the following steps:

s1, assembling a thermal vibration combined insulation real-time monitoring test system, mounting a test piece on a mounting platform, and carrying out insulation performance inspection on the test piece by adopting a cable insulation test device;

s2, performing normal-temperature vibration debugging on the vibration table and the mounting platform by adopting a response control method, and enabling a vibration measuring point on the upper surface of the mounting platform to meet vibration test conditions by debugging a control point on the vibration table outside a heating area;

s3, controlling the heating box to heat to a test temperature according to the maximum temperature rise rate, controlling the heating box to descend to the mounting platform by the heating box control device, and plugging a gap between the heating box and the mounting platform by flexible heat insulation materials;

s4, starting the vibration table to perform a test piece thermal vibration combined test, and performing vibration control according to the vibration condition of the vibration table debugged in the step S2;

s5, monitoring the insulation performance of the cable assembly by adopting a cable insulation testing device in the whole test process, and closing the cable insulation testing device after the thermal vibration combined test is finished for a period of time;

and S6, judging whether the insulation layer of the inner lead of the cable assembly fails or not by monitoring whether the insulation resistance value between any two pairs of leads in each cable assembly is lower than an allowable value or not in real time.

7. The aircraft cable assembly thermal-vibration combined insulation real-time monitoring test method according to claim 6, characterized by further comprising the following steps

If the cable assembly has the condition that the insulating layer of the internal conducting wire fails, the insulating property of the cable assembly is monitored in real time through a pure heating test and a normal-temperature vibration test respectively, and the reason of the insulating failure is determined.

8. The real-time monitoring and testing method for the thermal-vibration combined insulation of the aircraft cable assembly according to claim 6, wherein the step S2 specifically comprises the following steps:

s2.1, arranging a vibration sensor on the vibration table and the upper surface of the mounting platform, and connecting the vibration sensor with a vibration control acquisition device;

s2.2, using the vibration sensor on the upper surface of the mounting platform as a control point and using the vibration sensor on the vibration table as a measurement point, performing vibration debugging, and stopping debugging after confirming that the vibration sensor on the upper surface of the mounting platform meets vibration conditions;

s2.3, collecting vibration response of a vibration sensor of the vibration table as a newly set vibration condition, using the vibration sensor of the vibration table as a control point, using the vibration sensor on the upper surface of the mounting platform as a measurement point, and carrying out vibration debugging again to confirm that the vibration sensor on the upper surface of the mounting platform meets the original vibration condition;

and S2.4, removing the vibration sensor on the mounting platform in the heating area, and controlling by only adopting the vibration sensor on the vibration platform to perform a thermal vibration combined test.

9. The aircraft cable assembly thermal vibration joint insulation real-time monitoring test method according to claim 8, wherein the step S2.2 vibration debugging comprises two times of-6 dB condition vibration debugging and 0dB condition vibration debugging, and the step S2.3 vibration debugging is 0dB condition.

10. The aircraft cable assembly thermal vibration joint insulation real-time monitoring test method according to claim 8, wherein the vibration condition control requirements met by the vibration sensor on the upper surface of the mounting platform in step S2.2 and the vibration response requirements met by the vibration sensor on the upper surface of the mounting platform in step S2.3 are specifically: and the acceleration power spectral density deviation is controlled within +/-3 dB.

Technical Field

The invention belongs to the technical field of performance testing of aircraft cable assemblies, and particularly relates to a thermal vibration combined test system and method suitable for a cable assembly.

Background

With the increasing of the flight mach number of the aircraft, the combined action of the severe aerodynamic thermal load and the vibration load brings challenges to the laying, arrangement and thermal protection design of the cable assembly of the aircraft. Moreover, cabling and electrical connector arrangements are often less than ideal due to the space constraints imposed by the aircraft structure design. Therefore, the adaptability of the cable assembly in hot vibration environments is a technical risk point. The cable assembly is subjected to insulation online real-time monitoring by adopting a proper thermal vibration combined test method, and the method plays a very critical role in ensuring flight safety.

The ground thermal vibration combined test technology plays a vital role in the environmental adaptability assessment of aircraft structures and equipment. However, the heating method such as quartz lamp is usually used in the experiment, and the heating requirement for the uniformity of the cable and the electric connector cannot be met on the vibration table. And the cable and the electric connector are arranged in various forms, which is different from the installation form of the conventional structure. The general structural thermal vibration combined test method is not applicable, and a thermal vibration combined test method suitable for an aircraft cable assembly needs to be developed.

At present, corresponding thermal-vibration combined aging test devices are developed mainly aiming at underground laid power cable lines, overhead cables, underwater cables and the like at home and abroad. The aging phenomenon of the cable was mainly studied, for example, "a thermal-vibration combined aging test apparatus for cable samples (CN 206399790U)", "a thermal-vibration combined aging test apparatus for XLPE insulation sample sections (CN 205262935U)", "a test apparatus for umbilical cable unit electrical, thermal, vibration combined aging test apparatus (CN 202939241U)", and the like.

The aircraft cable assembly is different from the cable, and has the following differences in service environment, cable characteristics, failure modes and the like, so that the system research on the insulativity of the aircraft cable assembly under the thermal vibration combined condition is difficult to realize by adopting the test device: firstly, the pneumatic heating condition is severe, and the service temperature of the aircraft cable assembly is far higher than that of the cable; secondly, the cable components have different characteristics, the aircraft cable generally comprises a cable network consisting of a plurality of strands of different types of conducting wires with insulating layers, and special design is carried out on the cable components for meeting the temperature resistance requirement; and thirdly, the cable assembly may have the phenomena of insulation performance reduction in the thermal vibration test process and insulation performance recovery after the thermal vibration test is finished, and the cable assembly is difficult to leak risks by detection after the test. Therefore, for the development performance test of the aircraft cable assembly under the severe thermal vibration condition, a high-precision control method and a monitoring test implementation means are required.

Disclosure of Invention

The invention provides a thermal vibration combined insulation real-time monitoring test system and method for an aircraft cable assembly, aiming at the technical problem that the change of the insulation performance of the aircraft cable assembly cannot be monitored in real time under the thermal vibration combined condition in the prior art, and the insulation performance of the aircraft cable assembly can be monitored in real time on line under the severe high-temperature vibration condition.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a real-time monitoring and testing system for the thermal vibration and combined insulation of an aircraft cable assembly comprises an installation platform, a heating box control device, a vibration table, a vibration control acquisition device, a temperature data acquisition device and a cable insulation testing device; the mounting platform is fixed on the shaking table, set up test piece and temperature sensor on the mounting platform, fill flexible thermal insulation material between mounting platform and opening and mounting platform is covered to heating cabinet bottom opening, temperature and adjustment heating cabinet position in the heating cabinet controlling means control heating cabinet, vibration control collection system gathers shaking table vibration data, temperature sensor data in the heating cabinet is gathered to temperature data collection system, cable insulation testing arrangement and test piece stretch out the one end cable junction of heating cabinet, real-time supervision test piece insulating nature.

Furthermore, the test piece comprises a group of connected electric connectors, two ends of each electric connector carry a section of cable, one end of each cable extends out of the heating box and is subjected to insulation treatment by adopting a heat shrink tube, and the other end of each cable extends out of the heating box and is connected with the cable insulation testing device.

Furthermore, a plurality of sleeves, clamping plates and clamping hoops for mounting the test pieces are arranged on the upper surface of the mounting platform.

Furthermore, the non-examination section of the test piece positioned in the heating box is wrapped by the heat insulation layer, and the non-examination section positioned outside the heating box is fixed on the mounting platform by the fixing belt.

Furthermore, the bottom of the mounting platform, the position close to the connecting position with the vibration table are protected by a water cooling mode.

A real-time monitoring test method for thermal vibration combined insulation of an aircraft cable assembly comprises the following steps:

s1, assembling a thermal vibration combined insulation real-time monitoring test system, mounting a test piece on a mounting platform, and carrying out insulation performance inspection on the test piece by adopting a cable insulation test device;

s2, performing normal-temperature vibration debugging on the vibration table and the mounting platform by adopting a response control method, and enabling a vibration measuring point on the upper surface of the mounting platform to meet vibration test conditions by debugging a control point on the vibration table outside a heating area;

s3, controlling the heating box to heat to a test temperature according to the maximum temperature rise rate, controlling the heating box to descend to the mounting platform by the heating box control device, and plugging a gap between the heating box and the mounting platform by flexible heat insulation materials;

s4, starting the vibration table to perform a test piece thermal vibration combined test, and performing vibration control according to the vibration condition of the vibration table debugged in the step S2;

s5, monitoring the insulation performance of the cable assembly by adopting a cable insulation testing device in the whole test process, and closing the cable insulation testing device after the thermal vibration combined test is finished for a period of time;

and S6, judging whether the insulation layer of the inner lead of the cable assembly fails or not by monitoring whether the insulation resistance value between any two pairs of leads in each cable assembly is lower than an allowable value or not in real time.

Further, the method also comprises the following steps

If the cable assembly has the condition that the insulating layer of the internal conducting wire fails, the insulating property of the cable assembly is monitored in real time through a pure heating test and a normal-temperature vibration test respectively, and the reason of the insulating failure is determined.

Further, the step S2 specifically includes the following steps:

s2.1, arranging a vibration sensor on the vibration table and the upper surface of the mounting platform, and connecting the vibration sensor with a vibration control acquisition device;

s2.2, using the vibration sensor on the upper surface of the mounting platform as a control point and using the vibration sensor on the vibration table as a measurement point, performing vibration debugging, and stopping debugging after confirming that the vibration sensor on the upper surface of the mounting platform meets vibration conditions;

s2.3, collecting vibration response of a vibration sensor of the vibration table as a newly set vibration condition, using the vibration sensor of the vibration table as a control point, using the vibration sensor on the upper surface of the mounting platform as a measurement point, and carrying out vibration debugging again to confirm that the vibration sensor on the upper surface of the mounting platform meets the original vibration condition;

and S2.4, removing the vibration sensor on the mounting platform in the heating area, and controlling by only adopting the vibration sensor on the vibration platform to perform a thermal vibration combined test.

Further, the step S2.2 vibration debugging includes two times, namely-6 dB vibration debugging and 0dB vibration debugging, and the vibration debugging in the step S2.3 is 0 dB.

Further, the vibration condition control requirement satisfied by the vibration sensor on the upper surface of the mounting platform in step S2.2 and the vibration response requirement satisfied by the vibration sensor on the upper surface of the mounting platform in step S2.3 are specifically: and the acceleration power spectral density deviation is controlled within +/-3 dB.

Compared with the prior art, the invention has the beneficial effects that:

1) the invention provides a real-time monitoring and testing system and method for thermal vibration combined insulation of an aircraft cable assembly. The test piece comprises a group of connected electric connectors, two ends of each electric connector carry a section of cable, one end of each cable extends out of the heating box and is subjected to insulation treatment by adopting a heat shrink tube, the other end of each cable extends out of the heating box and is connected with a cable insulation testing device, and the cable insulation testing device is far away from the vibration heating device by arranging a non-examination section which is long enough. And (II) on the premise of ensuring heat sealing and vibration signal transmission, designing a cable routing space for the mounting platform, ensuring that the heat-shrinkable tube end is exposed outside the heating area to ensure the insulativity of the non-checking end on the one hand, and enabling the cable to be connected with an insulation testing device on the other hand. And (III) before the thermal vibration, the insulation test system is started to monitor the insulativity, and after the thermal vibration is finished for a period of time, the insulation test system is closed, so that the time of the fault is accurately positioned, and the phenomenon of missed detection is avoided. Whether the insulation resistance value between every two arbitrary conductor pairs with insulation layers in each cable assembly is lower than an allowable value is monitored in real time to judge whether the insulation layers of the inner conductors of the cable assemblies fail.

2) The invention provides a real-time monitoring and testing system and method for thermal vibration combined insulation of an aircraft cable assembly, which realize simulation of a real installation form and a fit size with the periphery of the cable assembly on an aircraft through design of an installation platform. The inseparable degree of different size sleeve simulation cables laminating in tunnel pipe, the cable of cooperation mounting platform is walked the line space, guarantees not to cause the damage to the cable because anchor clamps themselves under the vibration condition, and the phenomenon that vibration amplification appears in the cable is avoided to the mounting platform fixed band. The clamps with different specifications and distances are arranged through the mounting platform, so that the real fixing mode of a real cable is simulated. The card is used to simulate a special cable or electrical connector attachment.

3) The system-level method for the thermal vibration and insulation combined real-time monitoring test of the aircraft cable assembly provided by the invention can realize high-precision vibration control on the cable assembly through a vibration response control method.

The invention provides a new test method for monitoring the adaptability of the aircraft cable assembly under the severe high-temperature vibration condition, plays a verification role in the type selection, the thermal protection scheme and the constraint mode of the cable assembly, and provides guarantee for flight safety.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic diagram of a real-time thermal vibration combined insulation monitoring and testing system for an aircraft cable assembly according to an embodiment of the present invention;

fig. 2 is a schematic structural view of an aircraft cable assembly mounting platform according to an embodiment of the present invention.

Wherein, 1 is the mounting platform, 2 is the cable, 3 is the pyrocondensation pipe, 4 is the insulating layer, 5 is thermal-insulated cotton felt, 6 is the fixed band, 7 is the sleeve, 8 is the cardboard.

Detailed Description

The following provides a detailed description of specific embodiments of the present invention. In the following description, for purposes of explanation and not limitation, specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the device structures and/or processing steps that are closely related to the scheme according to the present invention are shown in the drawings, and other details that are not so relevant to the present invention are omitted.

The invention provides a thermal vibration combined insulation real-time monitoring test system of an aircraft cable assembly, which comprises an installation platform 1, a heating box and a heating box control device as shown in figure 1, the device comprises a vibrating table, a vibration control acquisition device, a temperature data acquisition device and a cable insulation testing device, wherein a mounting platform is fixed on the vibrating table, a test piece is arranged on the mounting platform, line spaces are formed in the two sides of the mounting platform according to the size of a cable, a flexible heat insulation material is filled between the opening at the bottom of a heating box and the opening of the mounting platform, the heating box control device controls the temperature of the heating box and adjusts the position of the heating box, the vibration control acquisition device acquires the vibration data of the vibrating table and the mounting platform, the temperature data acquisition device acquires and records the temperature sensor data in the heating box, the cable insulation testing device is connected with a cable at one end, extending out of the heating box, of the test piece in real. The aircraft cable assembly test piece participating in the test comprises cables and electric connectors, wherein after one group of electric connectors are connected, two ends of each electric connector carry a section of cable, one end of each cable extends out of a heating box and is subjected to insulation treatment by adopting a heat shrink tube 3, and the other end of each cable extends out of the heating box and is connected with a cable insulation testing device for real-time online monitoring of the insulation performance of the cables.

The mounting platform 1 is of a T-shaped structure and is mounted on a vibration table, and the vibration table is a vertical table and used for transmitting vibration signals. Because of the severe heat load, the vibration table is protected by adopting a water cooling mode at the bottom of the mounting platform and close to the connecting position with the vibration table.

The upper surface of the mounting platform 1 is provided with sleeves 7, clamping plates 8, hoops and the like with different sizes, and the sleeves, the clamping plates, the hoops and the like are used for simulating the real mounting form of cables and electric connectors on an aircraft and the fitting size of the cables and the electric connectors with the periphery, as shown in figure 2. Specifically, the sleeves 7 with different sizes are used for simulating the joint state of the cable and the pipe wall in the oil tank tunnel pipe, and the size of the sleeve needs to be designed according to the real gap; the clamping plate 8 is used for fixing a special cable or an electric connector on the mounting platform; the clamp is used for simulating the fixing mode of a conventional cable, and the selection type and the distance of the clamp and the length of the cable between the clamps are consistent with the real state. The checking sections of the cable and the electric connector are respectively placed in the sleeve and the clamping plate according to the actual installation form or are fixed by the clamping hoop, the non-checking section of the cable 2 in the heating box is wrapped by the heat insulation layer 4, and the non-checking section outside the heating box is fixed on the cylindrical surface of the installation platform outside the heating area by the fixing belt, as shown in figure 1.

The heating cabinet is an automatic temperature control heating cabinet, the opening of the heating cabinet faces downwards, after the heating cabinet is preheated to the test temperature, the heating cabinet control device controls the heating cabinet to descend to the level of the opening and the upper plane of the mounting platform, gaps around the opening and the mounting platform are plugged by flexible heat insulation materials such as heat insulation cotton felt 5, and the heating cabinet is used for heating and controlling cables and electric connectors. In the vibration loading process of the mounting platform, the hoisting position of the heating box does not change along with vibration, and the heating box is blocked by adopting flexible heat insulation materials between the heating box and the mounting platform, so that the heating box is prevented from heat leakage in the vibration process.

The temperature sensor is arranged on the upper surface of the mounting platform, arranged in the air on the same horizontal plane near the cable assembly in a support and other modes, connected with the temperature data acquisition device and used for carrying out real-time online monitoring on the temperature around the test piece in the heating box.

The invention provides a real-time monitoring test method for thermal vibration combined insulation of an aircraft cable assembly, which comprises the following steps:

1. the thermal vibration joint insulation real-time monitoring test system is assembled, a test piece is installed on an installation platform, and locking positions of a sleeve, a clamping plate, a hoop and the like and connecting pieces of the installation platform are marked for judging whether the connecting pieces are loosened after a test. And (3) insulating a cable at one end of the test piece by using a heat-shrinkable tube, fixing the cable outside the heating area on the mounting platform, fixing the other end of the test piece outside the heating area on the mounting platform, communicating the cable insulation test system, and inspecting the insulation performance of the cable assembly by using a cable insulation test device.

2. The response control method is adopted to carry out normal-temperature vibration debugging on the vibration table and the mounting platform, and due to the poor transmission of high-frequency signals in the connection relation, the mounting platform needs to be ensured to meet vibration test conditions, and the high-precision vibration control of the cable and the electric connector is realized. The method comprises the following specific steps:

2.1, the vibration sensor is arranged on the vibration table and the upper surface of the mounting platform and is connected with the vibration control acquisition device.

And 2.2, taking the vibration sensor on the upper surface of the mounting platform as a control point, taking the vibration sensor on the vibration table as a measuring point, carrying out vibration debugging, respectively carrying out-6 dB condition vibration debugging and 0dB condition vibration debugging, and stopping debugging after confirming that the vibration sensor on the upper surface of the mounting platform meets the vibration condition. In this embodiment, the requirements for controlling the vibration conditions are specifically: and the acceleration power spectral density deviation is controlled within +/-3 dB.

And 2.3, collecting the vibration response of the vibration sensor of the vibration table as a newly set vibration condition, taking the vibration sensor of the vibration table as a control point, and debugging again by taking the vibration sensor on the upper surface of the mounting platform as a measuring point. Carrying out 0dB condition vibration debugging, confirming that the surface vibration sensor on the mounting platform meets the original vibration condition, and specifically meeting the vibration response requirement as follows: and the acceleration power spectral density deviation is controlled within +/-3 dB. After confirmation, the vibration sensor on the vibration table is used as a control point to perform a formal thermal vibration test.

In this embodiment, the newly set vibration conditions are: 2.2, vibration response of the position of a sensor of the vibration table during vibration debugging under the condition of 0 dB; the original vibration conditions are as follows: vibration conditions in step 2.2.

And 2.4, removing the vibration sensor on the mounting platform in the heating area, and controlling by only adopting the vibration sensor on the vibration platform to perform a thermal vibration combined test.

The vibration sensor on the upper surface of the mounting platform meets vibration test conditions by debugging the control points on the vibration table positioned outside the heating area, and only the data of the vibration sensor on the vibration table is controlled and monitored in the formal thermal vibration combined test process without adding the vibration sensor on the mounting platform.

3. Controlling the heating box to heat to the test temperature according to the maximum temperature rise rate, controlling the heating box to descend to the mounting platform at the speed of 0.05m/s by the heating box control device, and plugging a gap between the heating box and the mounting platform by adopting a flexible heat insulation material;

4. and (4) starting the vibration table to carry out formal thermal vibration combined test on the cable assembly, and carrying out vibration control according to the vibration condition of the vibration table debugged in the step 2.3.

5. And in the whole test process, a cable insulation testing device is adopted to monitor the insulation performance of the cable assembly, and the cable insulation testing device is closed after the thermal vibration is finished for a period of time.

6. Whether the insulation resistance value between every two arbitrary conductor pairs with insulation layers in each cable assembly is lower than an allowable value is monitored in real time to judge whether the insulation layers of the inner conductors of the cable assemblies fail. If the condition that the inner conductor insulating layer loses efficacy appears, the testing system is adopted, the cable assembly insulativity real-time monitoring is carried out through the pure heating test and the cable assembly insulativity real-time monitoring is carried out through the normal-temperature vibration test, and the reason that the insulation loses efficacy is positioned is a thermal condition or a vibration condition. The cable assembly can be dissected for examination after the trial.

Features that are described and/or illustrated above with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

The many features and advantages of these embodiments are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of these embodiments which fall within the true spirit and scope thereof. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the embodiments of the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope thereof.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

The invention has not been described in detail and is in part known to those of skill in the art.