CN202433131U

CN202433131U - Device for inspecting load of bolt

Info

Publication number: CN202433131U
Application number: CN 201120523609
Authority: CN
Inventors: 王健志; 邱涛; 吴德锋; 何刚
Original assignee: Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Current assignee: Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Priority date: 2011-12-15
Filing date: 2011-12-15
Publication date: 2012-09-12
Anticipated expiration: 2021-12-15

Abstract

The utility model provides a device for inspecting the load of a bolt. The device is characterized in that sensitive elements are arranged in a small hole in the center of the bolt. The device has the advantages that the load of the bolt can be measured accurately without inversion and conversion, so that the problem of difficulty in arrangement of the bolt and strain gauges, which is caused by a small bolt structure in the conventional technology of measuring the strain gauges is solved.

Description

A kind of device of checking bolt load

Technical field

The present invention relates to bolt load monitoring field; Relate in particular to a kind of device of checking bolt load; Can be applicable in the bolt load monitoring technology of aircaft configuration; Also can be used for fields such as Aero-Space, machinery, the isostructural detail analysis of building, life appraisal and health monitoring in addition, in following intelligent engineering structure, be with a wide range of applications especially.

Background technology

Well-known engineering structure all has the rigidity that characterizes its inherent characteristic; Its external manifestation is exactly that the size of malformation and bearing load presents certain relation; Under the situation of known structure rigidity; Through measurement structure distortion, just can calculate the magnitude of load that it bears, such principle carries out with regard to being based in mechanical meaurement.

The method of measuring distortion in the prior art is a lot, for the large-deformation measuring of absolute displacement in several millimeters arrive a hundreds of millimeter scope, can use Steel Ruler, displacement transducer etc.; Absolute displacement is measured at several microns small deformations to a hundreds of micron, can use milscale, high accuracy displacement sensor etc.; And in actual engineering structure, the measurement of the microdeformation of relative deformation between tens to several thousand microstrains the most also is that the most frequently used method just is to use foil gauge, and common foil gauge has strain ga(u)ge, fiber grating strain meter etc.

Bolt as a kind of the most common also be one of most important engineering structure part, the same with other structure, the distortion after its stand under load all is very small usually; For also can adopting foil gauge to measure on this little Deformation Theory, but because the singularity of bolt arrangement, its compact conformation, size is little, relative rigidity is big; Many times do not possess the condition of pasting foil gauge; Can't directly measure bolt load, yet the engineering structure part is much all through Bolt Connection; Because how the importance of bolt accurately measures the difficult problem that bolt load is engineering circle always.

Usually the way of employing is at present, on bolt part such as auricle, pastes foil gauge, and is through measuring the load of stress repulsion on bolt on the auricle, as shown in Figure 1; Wherein 1 is bolt part auricle, the 2nd, and bolt hole, the 3rd, foil gauge; But, as shown in Figure 2, when auricle receives a load p; The stress distribution of auricle is quite complicated, and wherein 1 is bolt part auricle, the 2nd, and bolt hole; The 03rd, the foil gauge position, the 04th, the position that stress is concentrated is because the foil gauge patch location is difficult to accurate location; Therefore the load measurement result need instead push away conversion, is to be difficult to accurately calculate track bolt load by the stress value of several measurement points only, can't accurately record bolt load by this method.

Summary of the invention

The technical matters that the utility model solved: in order to satisfy requirement of engineering; Metabolies such as bending generally can appear after carrying according to bolt; We provide a kind of device that can directly monitor bolt load, do not need the anti-conversion that pushes away, through using the bolt load sensor; Can accurately record bolt load, solve the contradiction of and foil gauge difficult arrangement less in the current foil gauge measuring technique because of bolt arrangement.

Technical scheme of the present invention is: a kind of device of ability Direct Test bolt load is provided, has been provided with through hole at the bolt center, sensitive element is equipped with in through hole inside; Two ends is fixed with ring stiffener and is strengthened; Said sensitive element can be fiber grating, is set to one or more; Core can also be equipped with in said through hole inside, and the periphery of core is provided with piezoelectric membrane.

Beneficial effect of the present invention is: compare existing through sticking on the device of the anti-ear pushing sheet of the measurement result of foil gauge bolt load on the auricle; We can directly measure the load that acts on the bolt by the bolt load sensor of invention; Avoided because auricle stress is complicated, the foil gauge patch location is difficult to accurately locate and the load measurement result need instead push away uncertain factors such as conversion; Can obviously improve the accuracy of load measurement, solve the contradiction of and foil gauge difficult arrangement less in the current foil gauge measuring technique because of bolt arrangement.

Description of drawings

Fig. 1 pastes the synoptic diagram that foil gauge is measured the bolt load process on the conventional bolt fixture auricle.

Fig. 2 is a stress distribution simulation drawing behind the bolt part auricle stand under load.

Fig. 3 is the synoptic diagram of monitoring bolt load process in the utility model preferred embodiment.

Fig. 4 is the structural representation that detects bolt in the utility model preferred embodiment with fiber grating.

Fig. 5 is the structural representation that detects bolt in the utility model preferred embodiment with piezoelectric membrane.

Embodiment

Below through concrete embodiment and combine 3～5 pairs of the utility model of accompanying drawing to be described in further detail.

Fig. 3 is seen in the signal of the utility model bolt load measuring process, mainly comprises fiber grating 40, ring stiffener 21, parts such as bolt 20, nut 30; Be used to measure the bolt load of bolt auricle structure, fiber grating 40 is a sensitive element, through the cementing agent solidification by cement in the aperture at bolt center; Two ends is with ring stiffener 21 fixing and reinforcements; Auricle deforms after bolt 20 carries under the load p effect, and the fiber grating 40 that is placed in the bolt center is out of shape thereupon; Obtain this deformation signal through fiber grating 40 (FBG) demodulators, obtain useful bolt load size information through signal analysis with after handling subsequently.

Fig. 4 is the structural representation that detects bolt in the utility model preferred embodiment with fiber grating, and the special aperture at the bolt center is because the material of bolt core is very little for the contribution that it holds curved ability; Pour into fiber grating 40 in the centre in hole and pass through cementing agent filling material 22 solidification by cement in the aperture at bolt center, to the material formation sensitizing range of deformation sensitive, behind the bolt stand under load; Little axially bored line bends; Sensitive material in the aperture can change accordingly in perception, through the length of precise design aperture and sensitizing range, just possibly detect this variation; Through gathering the output signal of sensitive element; And the situation of change of these signals analyzed and handle, find out the relation of signal situation of change and bolt load, thereby reach the purpose of monitoring bolt load.

Fig. 5 is the structural representation that detects bolt in the utility model preferred embodiment with piezoelectric membrane, at the bolt center one hole is set, and core 23 is equipped with at the center, hole; The periphery of core 23 is provided with piezoelectric membrane 50, when auricle under the load p effect, bolt 20 deforms after carrying; Core 23 is out of shape thereupon, because material bent face modulus is different, is out of shape inharmonious generation and opens face 24 and closing face 25; Closing face 25 is experienced pressure; Receive and convert into electric signal by piezoelectric membrane 50,, the situation of change of these electric signal is analyzed and handled through gathering the output signal of piezoelectric membrane 50; Find out the relation of change in electric situation and bolt load, thereby reach the purpose of monitoring bolt load.

The preferred embodiment that the above is merely the utility model is not in order to limit the application range of the utility model; All other do not break away from the equivalence of being accomplished under the essence that the utility model discloses and change or modify, and all should be included in following claims scope.

Claims

1. device of checking bolt load, it is characterized in that: be provided with through hole at the bolt center, through hole inside is provided with sensitive element.

2. the device of check bolt load according to claim 1 is characterized in that: said sensitive element is a fiber grating, can be set to one or more; Two ends is fixed with ring stiffener and is strengthened.

3. the device of check bolt load according to claim 1 is characterized in that: core is equipped with in said through hole inside, and the periphery of core is provided with piezoelectric membrane.