Bearing load measurement strain gauge, strain body thereof and manufacturing and mounting method

Abstract

The invention provides a bearing load measurement strain gauge, a strain body thereof and a manufacturing and mounting method. The bearing load measurement strain gauge comprises a protective layer, a sensitive layer and an insulating layer which are sequentially arranged from top to bottom and are mutually bonded and fixed, the protective layer is made of a high-temperature-resistant ceramic material, the sensitive layer is made of an alloy to form a gate structure, and the insulating layer is made of an aluminum nitride ceramic material. And the protective layer, the sensitive layer and the insulating layer are bonded by adopting a nano-modified ceramic-based adhesive. The bearing load measurement strain gauge provided by the invention can realize accurate measurement and long-term stable work of the strain gauge at high temperature.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of strain gauges, in particular to a bearing load measuring strain gauge, a strain body thereof and a manufacturing and mounting method. BACKGROUND

[0002] During ship navigation, the bearing load of the propulsion shafting is a key parameter affecting the safety and efficiency of the ship operation. The traditional bearing load measuring method relies on resistance strain gauges, but in a high-temperature environment, the adhesive of ordinary strain gauges is prone to failure, the bonding strength between the substrate and the shaft surface decreases, and the measurement result is distorted. In the prior art, the laying process of high-temperature strain gauges mostly uses ordinary adhesives or simple surface treatment methods, which will cause degradation of the adhesive, thermal noise interference and falling risk above 200 DEG C, and rely on a complex external cooling system, which is difficult to meet the long-term stable measurement demand in a high-temperature environment. SUMMARY

[0003] The main purpose of the application is to provide a bearing load measuring strain gauge and a high-temperature laying process thereof, so as to realize accurate measurement and long-term stable work of the strain gauge in a high-temperature environment.

[0004] To achieve the above purpose, the application provides a bearing load measuring strain gauge, which comprises a protective layer, a sensitive layer and an insulating layer fixedly bonded from top to bottom and between each other, wherein, The protective layer is made of high-temperature resistant ceramic material, the sensitive layer is made of alloy to form a gate structure, the insulating layer is made of aluminum nitride ceramic material, and the protective layer, the sensitive layer and the insulating layer are bonded by a nano-modified ceramic-based adhesive.

[0005] Preferably, the adhesive is made of Al2O3, SiO2 and ZrO2 as a matrix, and carbon nanotubes are added as a reinforcing phase.

[0006] Preferably, the high-temperature resistant ceramic material is one or more of alumina ceramic, silicon nitride ceramic, silicon carbide ceramic or zirconia ceramic; the sensitive layer is made of platinum-tungsten alloy or nickel-chromium alloy, and the gate structure is prepared on the ceramic substrate by photolithography or laser technology.

[0007] Preferably, the bearing load measuring strain gauge is made by using a mask batch pasting process and a step-by-step baking and curing technology.

[0008] The application further provides a bearing load measuring strain body, which comprises the bearing load measuring strain gauge and further comprises a magnetic material layer and a substrate layer arranged below the bearing load measuring strain gauge in sequence, and a wire electrically connected with the bearing load measuring strain gauge.

[0009] Preferably, the magnetic material layer and the substrate layer are fixed by nano-modified ceramic-based adhesive bonding; the magnetic material layer is fixed by adhesive bonding with the insulating layer of the bearing load measurement strain gauge.

[0010] Preferably, the magnetic material layer is made of cobalt-iron alloy, the substrate layer is formed by alloying and surface ceramic treatment, and the conductive wire forms ohmic contact with the sensitive layer through conductive paste.

[0011] Preferably, the bearing load measurement strain gauge further comprises a fastener passing through the insulating layer, the magnetic material layer and the substrate layer of the bearing load measurement strain gauge.

[0012] The application further provides a manufacturing method of the bearing load measurement strain gauge, comprising the following steps: The protective layer is formed by high-temperature ceramic through isostatic pressing, high-temperature sintering and grinding to the required thickness, the sensitive layer is formed by etching the gate structure on the ceramic substrate through photolithography or laser technology, the insulating layer is prepared by aluminum nitride ceramic material, the magnetic material layer is prepared on the SiC coating substrate by magnetron sputtering, and the substrate layer is formed by alloying and surface ceramic treatment. The protective layer, the sensitive layer, the insulating layer, the magnetic material layer and the substrate layer are sequentially bonded by nano-modified ceramic-based adhesive, and are cured by a step-by-step baking process. The conductive wire forms ohmic contact with the electrode pad of the sensitive layer through conductive paste, and is then welded and reinforced.

[0013] The application further provides a mounting method of the bearing load measurement strain gauge, comprising the following steps: Surface treatment: the shaft to be mounted with the strain gauge is subjected to surface treatment to ensure that the mounting surface flatness is less than or equal to 0.01mm; Laser-assisted positioning: the maximum strain point determined by finite element analysis is preliminarily marked on the surface-treated shaft, and the bonding position is precisely positioned by a laser; Electromagnetic pressure treatment: after the bearing load measurement strain gauge is bonded with the adhesive on one side, it is bonded to the determined position on the shaft, and the electromagnetic pressure device provides uniform and constant pressure to the bearing load measurement strain gauge; Gradient curing process treatment: different target temperatures are reached at different heating rates in stages, and the temperature is stabilized for a preset time, and after the temperature is raised, the temperature is naturally cooled to room temperature, so as to optimize the performance of the adhesive layer and release the thermal stress.

[0014] The bearing load measurement strain gauge has the following beneficial effects: 1. The application innovatively adopts mask batch pasting process and step-by-step baking curing technology, and the over-stage treatment ensures the uniformity of gluing; the strain transmission efficiency in 400 DEG C high temperature environment is significantly improved; compared with the traditional one-time gluing process, the risk of grid wire falling is reduced by more than 80%.

[0015] 2. By adopting SiC protective layer and nano-modified adhesive, the strain gauge can improve the strain transmission efficiency at 400 DEG C high temperature, and can work stably at 500 DEG C extreme working condition, and exhibits excellent thermal cycle stability. 3. The bearing load measuring strain gauge effectively solves the problems of adhesion strength reduction, thermal strain noise elimination and anti-vibration falling in high temperature environment, and can realize precise measurement and long-term stable work at 500 DEG C high temperature, thereby providing a reliable solution for ship shafting safety monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The structure diagram of the protective layer and the sensitive layer in the bearing load measuring strain gauge of the application is shown. Figure 2 The structure diagram of the bearing load measuring strain gauge of the application is shown. Figure 3 The structure diagram of the bearing load measuring strain gauge of the application is shown. Figure 4 The structure diagram of the bearing load measuring strain gauge of the application is shown.

[0017] In the figure, 11 is a protective layer, 12 is a sensitive layer, 13 is an insulating layer, 14 is an adhesive, 2 is a magnetic material layer, 3 is a substrate layer, 4 is a wire, 5 is a fastener, 6 is a bearing, 7 is a shaft, and 8 is a bearing load measuring strain gauge.

[0018] The realization of the object of the application, the functional characteristics and the advantages will be further described with reference to the accompanying drawings. DETAILED DESCRIPTION

[0019] It should be understood that the specific embodiments described herein are only used to explain the application, and are not used to limit the application.

[0020] It should be noted that in the description of the present application, the terms "transverse", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0021] The present application provides a bearing load measurement strain gauge.

[0022] Referring to Figure 1 In the preferred embodiment, a bearing load measurement strain gauge includes a protective layer 11, a sensitive layer 12 and an insulating layer 13 fixed from top to bottom and bonded to each other, wherein The protective layer 11 is made of high-temperature-resistant ceramic material, the sensitive layer 12 is made of alloy in a grid structure, the insulating layer 13 is made of aluminum nitride ceramic material, and the protective layer 11, the sensitive layer 12 and the insulating layer 13 are bonded by a nano-modified ceramic-based adhesive 14.

[0023] The high-temperature-resistant ceramic material can be made of one or more of alumina ceramic, silicon nitride ceramic, silicon carbide ceramic or zirconia ceramic. The sensitive layer 12 is made of platinum-tungsten alloy or nickel-chromium alloy, or other types of alloy materials that meet the high-sensitivity strain-resistance change, and the grid structure is prepared on the ceramic substrate by photolithography or laser technology The bearing load measurement strain gauge is made by mask batch pasting process and step-by-step baking curing technology. The mask batch pasting process refers to positioning the protective layer 11, the insulating layer 13 and the sensitive layer 12 according to the high-precision mask plate, and pasting between different layers. The step-by-step baking curing technology is to bake and cure the protective layer 11, the insulating layer 13 and the sensitive layer 12 at different temperatures in stages. The step-by-step baking curing technology is to heat at different heating rates to different target temperatures in stages, and stabilize for a preset time. After completing the heating, it is naturally cooled to room temperature to optimize the performance of the adhesive layer and release the thermal stress.

[0024] Specifically, in the present embodiment, the adhesive 14 is made of Al2O3, SiO2 and ZrO2 as the base body, and carbon nanotubes as the reinforcing phase.

[0025] The adhesive 14 can be composed of 60% Al2O3, 25% SiO2 and 15% ZrO2 as a base body, and 2% carbon nanotube reinforcing phase is added, and the performance advantages are: high temperature shear strength is greater than or equal to 15 MPa; thermal expansion coefficient matching degree reaches 95%; and fracture toughness is increased by 40%.

[0026] The main functions of the protective layer 11 include: preventing the sensitive layer 12 from sublimation and oxidation in a high-temperature environment; and maintaining the structural stability of the sensitive layer 12. The sensitive layer 12 adopts a precise gate structure design, and the core function is to convert mechanical strain into an accurate resistance change signal.

[0027] The bearing load measurement strain gauge provided by the application has the following beneficial effects: 1. The mask batch pasting process and the step-by-step baking and curing technology are innovatively used to ensure the uniformity of the glue joint through the over-stage processing; the strain transmission efficiency in a 400 DEG C high-temperature environment is significantly improved; compared with the traditional one-time glue coating process, the risk of grid wire falling is reduced by more than 80%.

[0028] 2. By using the protective layer 11 and the nano-modified adhesive 14, the strain transmission efficiency of the strain gauge is improved at 400 DEG C high temperature, and the strain gauge can work stably at 500 DEG C extreme working condition, and excellent thermal cycle stability is exhibited. 3. The bearing load measurement strain gauge effectively solves the problems of adhesive strength reduction, thermal strain noise elimination and anti-vibration falling in a high-temperature environment, realizes accurate measurement and long-term stable work at 500 DEG C high temperature, and provides a reliable solution for ship shafting safety monitoring.

[0029] 4. By using the combination of the SiC or Al2O3 ceramic protective layer 11, the platinum-tungsten alloy or nickel-chromium alloy sensitive layer 12 and the AlN ceramic insulating layer 13, the thermal stability, insulation and strain transmission efficiency of the overall structure in a high-temperature environment are significantly improved, and the use temperature limit of the traditional polymer-based strain gauge is broken through.

[0030] The application further provides a bearing load measurement strain body.

[0031] Referring to Figure 2 and Figure 3 In the preferred embodiment, a bearing load measurement strain body comprises a bearing load measurement strain gauge, further comprises a magnetic material layer 2 and a substrate layer 3 arranged below the bearing load measurement strain gauge in sequence, and a wire 4 electrically connected with the bearing load measurement strain gauge. The specific structure and beneficial effects of the bearing load measurement strain body are referred to the above-mentioned embodiments, and will not be described here.

[0032] In the embodiment, the magnetic material layer 2 and the substrate layer 3 are fixed by the nano-modified ceramic-based adhesive 14. The magnetic material layer 2 is fixed by the adhesive 14 and the insulating layer 13 of the bearing load measurement strain gauge.

[0033] Specifically, in the embodiment, the magnetic material layer 2 is made of cobalt-iron alloy, which can generate a magnetic induction intensity of ≥0.5T in a high-temperature environment, effectively compensating for the attenuation of the high-temperature performance of the adhesive 14. The magnetic material layer 2 is made of a cobalt-iron alloy thin film prepared by magnetron sputtering on a SiC coating substrate. The substrate layer 3 is formed by alloying (stainless steel or titanium alloy can be used) and surface ceramic treatment. The material has the characteristics of thermal conductivity ≥120W / (m•K), thermal expansion coefficient 4.5×10-6 / ℃, and anti-thermal shock cycle number ≥100 times.

[0034] Further, the bearing load measurement strain body also includes a fastener 5 penetrating the insulating layer 13, the magnetic material layer 2, and the substrate layer 3 of the bearing load measurement strain gauge. The fastener 5 is made of a high-temperature alloy, which functions to ensure the close contact between the magnetic material layer 2 and the insulating layer 13, maintain a stable magnetic circuit structure, and withstand an installation torque of 10N•m.

[0035] In the embodiment, the lead wire 4 forms an ohmic contact with the sensitive layer 12 through conductive paste, thereby ensuring the stability of signal transmission.

[0036] The bearing load measurement strain body provided by the application effectively solves the problems of adhesive strength decline, thermal strain noise elimination, and anti-vibration shedding in a high-temperature environment, realizes precise measurement and long-term stable operation at a temperature of 500℃, and provides a reliable solution for ship shafting safety monitoring.

[0037] The application also provides a manufacturing method of the bearing load measurement strain body.

[0038] In the preferred embodiment, the manufacturing method of the bearing load measurement strain body comprises the following steps: In step S1, the protective layer 11 is formed by isostatic pressing and high-temperature sintering of high-temperature resistant ceramic, and then ground to the required thickness; the sensitive layer 12 is formed by etching an alloy material on a ceramic substrate through photolithography or laser technology to prepare a gate structure; the insulating layer 13 is prepared by aluminum nitride ceramic material; the magnetic material layer 2 is prepared by magnetron sputtering on a SiC coating substrate; and the substrate layer 3 is formed by alloying and surface ceramic treatment. In step S2, the protective layer 11, the sensitive layer 12, the insulating layer 13, the magnetic material layer 2, and the substrate layer 3 are sequentially bonded by the nano-modified ceramic-based adhesive 14, and are cured by a step-by-step baking process. Step S3, the conductive paste is used to form an ohmic contact between the lead wire 4 and the electrode pad of the sensitive layer 12, and then the welding is reinforced.

[0039] By using the manufacturing method, the bonding strength of the high-temperature strain body at 500 DEG C is greater than or equal to 35 MPa, the measurement repeatability reaches 99.5%, and the data fluctuation range is reduced by 80%. Through optimization of the structure design, the risk of grid wire falling is controlled to be less than 5%, the service life is prolonged to more than 5000 hours, and the reliability of the measurement system is greatly improved.

[0040] The application further provides a mounting method of the bearing load measurement strain body.

[0041] With reference to Figure 4 In the preferred embodiment, the mounting method of the bearing load measurement strain body comprises the following steps: Step S10, surface treatment: the shaft to be installed with the strain body is subjected to surface treatment to ensure that the flatness of the installation surface is less than or equal to 0.01 mm; Step S20, laser-assisted positioning: reference marks are preliminarily made on the maximum strain points of the shaft subjected to the surface treatment through finite element analysis, and the bonding position is precisely positioned by using a laser; Step S30, electromagnetic pressure treatment: after the bearing load measurement strain body is bonded with the adhesive 14 on one side, the bearing load measurement strain body is bonded to the determined position on the shaft, and the electromagnetic pressure device is used to provide uniform and constant pressing force for the bearing load measurement strain body; Step S40, gradient curing process treatment: the temperature is raised at different rates in stages to different target temperatures, and the temperature is stabilized for a preset time; after the temperature is raised, the temperature is naturally cooled to room temperature, so as to optimize the performance of the adhesive layer and release the thermal stress.

[0042] Step S10 specifically comprises the following steps: under the premise that the shaft diameter and the surface flatness meet the standards, the surface of the shaft is preliminarily cleaned by using an organic solvent such as alcohol or acetone; different grits of sandpaper are used to polish in batches to ensure that the surface roughness is uniform, so as to improve the bonding force of the strain sheet and reduce the surface resistance error; and the polished surface is finely cleaned by using an organic solvent such as alcohol or acetone.

[0043] The step S20 specifically comprises the following steps: preliminarily marking a reference mark according to the maximum strain point determined by the finite element analysis on the installation area of the surface-treated shaft; fixing a laser device so that the laser beam axis of the laser device is parallel to or at a preset angle with the geometric axis of the bearing or a calibrated installation reference surface; adjusting the direction of the laser beam of the laser device so that the light spot of the laser beam is projected on the center reference mark on the surface of the bearing; moving the center position of the back surface of the bearing load measuring strain body to a position coinciding with the light spot of the laser beam, at this time, the strain body is at the optimal pasting position calculated in theory; and keeping the position unchanged and preliminarily pressing and fixing in this state.

[0044] The step S30 specifically comprises the following steps: starting the electromagnetic pressing device, the electromagnet generates a strong magnetic field of 0.5T-1.0T, provides uniform and constant pressing force for the strain body in the initial curing stage, ensures that the glue layer is free of bubbles, has uniform thickness and is in close contact, and simultaneously magnetizes the magnetic material layer 2 in the strain body.

[0045] The temperature rising rate, target temperature and stable time after reaching the target in the step S40 are determined through experiments with the maximum curing effect as the target.

[0046] The installation method provided by the application can realize accurate positioning of the bearing load measuring strain body and ensure that the bearing load measuring strain body is firmly bonded, thereby ensuring accurate measurement and long-term stable work of the bearing load measuring strain body at high temperature, and providing a reliable solution for safety monitoring of a ship shafting.

[0047] The above is only the preferred embodiment of the application, and does not limit the patent scope of the application, and any equivalent structural transformation using the content of the specification and the drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the application.

Claims

1. A bearing load measuring strain gage characterized by, It comprises a protective layer, a sensitive layer and an insulating layer which are fixed by bonding from top to bottom and among each other, wherein, The protective layer is made of high-temperature resistant ceramic material, the sensitive layer is made of alloy in a grid structure, the insulating layer is made of aluminum nitride ceramic material, and the protective layer, the sensitive layer and the insulating layer are bonded by nano-modified ceramic-based adhesive.

2. The bearing load measuring strain gage of claim 1 wherein, The adhesive is made of Al2O3, SiO2 and ZrO2 as a base and carbon nanotubes as a reinforcing phase.

3. The bearing load measuring strain gage of claim 1 wherein, The high-temperature resistant ceramic material is one or more of alumina ceramic, silicon nitride ceramic, silicon carbide ceramic or zirconia ceramic; the sensitive layer is made of platinum-tungsten alloy or nickel-chromium alloy, and the grid structure is prepared on the ceramic substrate by photolithography or laser technology.

4. The bearing load measuring strain gage of any one of claims 1 to 3, wherein, The bearing load measuring strain gauge is made by mask batch bonding process and step-by-step baking curing technology.

5. A bearing load measuring strain body characterized by, It further comprises a magnetic material layer and a substrate layer arranged in sequence below the bearing load measuring strain gauge, and a wire electrically connected to the bearing load measuring strain gauge.

6. The bearing load measuring strain body of claim 5, wherein, The magnetic material layer and the substrate layer are fixed by bonding through nano-modified ceramic-based adhesive; the magnetic material layer is fixed by bonding with the insulating layer of the bearing load measuring strain gauge through the adhesive.

7. The bearing load measuring strain gage of claim 5 wherein, The magnetic material layer is made of cobalt-iron alloy, and the substrate layer is formed by alloying and then ceramicizing the surface; the wire forms ohmic contact with the sensitive layer through conductive paste.

8. The bearing load measuring strain gage of claim 5 wherein, It further comprises a fastener penetrating the insulating layer, the magnetic material layer and the substrate layer of the bearing load measuring strain gauge.

9. The method of claim 5 to 8, wherein the method further comprises the step of: It comprises the following steps: ​ The protective layer is formed by high-temperature resistant ceramic through isostatic pressing, high-temperature sintering and then grinding to the required thickness, the sensitive layer is formed by etching alloy material on the ceramic substrate through photolithography or laser technology to prepare the grid structure, the insulating layer is prepared by aluminum nitride ceramic material, the magnetic material layer is prepared on the SiC coating substrate by magnetron sputtering, and the substrate layer is formed by alloying and then ceramicizing the surface; The protective layer, the sensitive layer, the insulating layer, the magnetic material layer and the substrate layer are sequentially bonded by nano-modified ceramic-based adhesive, and are cured by step-by-step baking process; The wire forms ohmic contact with the electrode pad of the sensitive layer through conductive paste, and is then welded.

10. A method of mounting a bearing load measuring strain body according to any one of claims 5 to 8, characterised in that, It comprises the following steps: Surface treatment: the shaft to be installed with the strain body is surface treated to ensure that the installation surface flatness is less than or equal to 0.01mm; Laser-assisted positioning: the maximum strain point determined by finite element analysis is preliminarily marked on the surface-treated shaft, and the bonding position is precisely positioned by a laser; Electromagnetic pressure treatment: after the adhesive is bonded to one side of the bearing load measuring strain body, the bearing load measuring strain body is bonded to the determined position on the shaft, and the electromagnetic pressure device provides uniform and constant pressure to the bearing load measuring strain body; Gradient curing process treatment: different heating rates are used to heat to different target temperatures in stages, and the temperature is stabilized for a preset time, and after the heating is completed, the temperature is naturally cooled to room temperature to optimize the performance of the adhesive layer and release the thermal stress.

Images