An instrument and method for accurately testing the viscoelastic parameters of optical glass materials

Abstract

The present invention relates to the technical field of material viscoelasticity testing. The present invention provides an instrument and a method for accurately testing the viscoelastic parameters of optical glass materials. The present invention includes: a frame; a working chamber including a sealed cavity, heating elements provided around the sealed cavity, a sample holder, and a force sensor; both the sample holder and the force sensor are arranged in the sealed cavity; a force module includes a lifting bracket, an electromagnetic inductor, a pressing block, and a pressure ejector rod; the pressing block is arranged in parallel on one side of the lifting bracket where the electromagnetic inductor is provided; the lifting bracket can move up and down to drive the pressure ejector rod to contact the sample, and after the electromagnetic inductor is energized, it can provide a downward step force for the pressing block and the pressure ejector rod; a displacement detection component includes a displacement sensor for monitoring the axial deformation of the sample after being stressed. The present invention can achieve an ideal step force, meet more ideal creep test load conditions; ensure the acquisition of ideal viscoelastic creep data, and improve the accuracy of the test.

Description

Technical Field

[0001] The present invention relates to the technical field of material viscoelasticity testing, and in particular to an instrument and a method for accurately testing the viscoelastic parameters of optical glass materials at high temperatures. Background Art

[0002] The viscoelastic parameters (such as shear relaxation modulus) of optical glass materials at high temperatures are key physical quantities for studying and predicting the fluidity and stress relaxation behavior of glass during precision forming processes.

[0003] However, the servo press equipment used in traditional viscoelasticity testing methods cannot provide an ideal step load, resulting in inaccurate viscoelastic creep data of the glass. In addition, in traditional testing, under the action of a large load pressure, the cross-sectional area of the glass specimen continuously increases and expands into a drum shape on the side under the interference of interfacial friction, further leading to the distortion of viscoelastic creep data.

[0004] Therefore, there is a need to provide a new instrument and method for the viscoelastic parameters of glass materials to accurately obtain the viscoelastic parameters of the glass. Summary of the Invention

[0005] For this reason, the technical problem to be solved by the present invention is to overcome the prior art.

[0006] To solve the above technical problem, on the one hand, the present invention provides an instrument for accurately testing the viscoelastic parameters of optical glass materials, including:

[0007] A frame including columns;

[0008] A working chamber including an airtight cavity provided on one side of the column, heating elements provided around the airtight cavity, a sample holder, and a force sensor; both the sample holder and the force sensor are arranged in the airtight cavity, and the force sensor is arranged at the bottom of the sample holder;

[0009] A force module including a first driving member, a lifting bracket slidably connected to the column, an electromagnetic inductor provided on the lifting bracket, a pressing block forming a rotating pair with the outer end of the lifting bracket, and a pressure ejector rod provided at the bottom of the pressing block; the pressing block is arranged in parallel on the side of the lifting bracket where the electromagnetic inductor is provided; the lifting bracket can move up and down to drive the pressure ejector rod to contact the sample, and after the electromagnetic inductor is energized, it can provide a downward step force for the pressing block and the pressure ejector rod;

[0010] A displacement detection assembly including a displacement sensor provided on the top of the pressing block, and the displacement sensor is used to monitor the axial deformation of the sample after being stressed.

[0011] In an embodiment of the invention, the present application further includes a control component, and the control component is electrically connected to the heating element, the force sensor, the electromagnetic inductor, and the first driving member.

[0012] In one embodiment of the invention, the frame further includes a base fixedly connected to the bottom of the column and a top plate fixedly connected to the top of the column, and the working chamber is arranged on the base.

[0013] In one embodiment of the invention, the displacement sensor includes a detection body connected to the frame and a sensor connecting rod arranged at the bottom of the detection body; the displacement detection assembly further includes a cover body arranged on the top of the top plate, and the sensor connecting rod passes through the first through hole of the top plate and then is connected to the pressing block.

[0014] In one embodiment of the invention, the working chamber further includes a guiding member and a cover plate, the heating member is slidably connected to the outer wall of the guiding member up and down, and after the heating member rises, a sealed cavity is formed by enclosing with the cover plate and the guiding member; the cover plate is connected to one side of the column, and the cover plate is provided with a second through hole, and the pressure ejector rod passes through the second through hole and extends into the sealed cavity.

[0015] In one embodiment of the invention, the working chamber further includes a lifting cylinder body, the telescopic end of the lifting cylinder body is connected to the heating member, and the telescopic movement of the lifting cylinder body drives the heating member to lift.

[0016] In one embodiment of the invention, the working chamber further includes a guide rail arranged on the outer wall of the guiding member and a slider matched with the guide rail, and the slider is connected to the inner wall of the heating member.

[0017] In one embodiment of the invention, the heating member is an infrared heating tube.

[0018] In one embodiment of the invention, the sample holder is made of quartz glass.

[0019] In one embodiment of the invention, one end of the lifting bracket connected to the column is provided with a slider, the slider is sleeved on the column, and the slider is connected to the first driving member, and the first driving member drives the slider to lift up and down along the column.

[0020] On the other hand, the present invention provides a method for accurately testing the viscoelastic parameters of optical glass materials, and the following steps are carried out by using any one of the above embodiments:

[0021] The lifting bracket descends until the pressure ejector rod contacts the upper surface of the sample; the electromagnetic inductor is powered on to provide a downward step force for the pressing block, the step force is applied to the sample to cause the sample to deform, and at the same time, the force sensor monitors the value of the step force applied to the sample, and the displacement sensor monitors the axial deformation of the sample after being stressed.

[0022] The above technical solutions of the invention have the following beneficial effects compared with the prior art:

[0023] The instrument and method for accurately testing the viscoelastic parameters of optical glass materials according to the present invention can achieve an ideal step force and meet more ideal creep test load conditions. During the test, only axial creep deformation of a few micrometers to dozens of micrometers occurs, and no obvious bulging occurs on the side, thereby ensuring constant pressure and reducing the interference of friction, so as to ensure the acquisition of ideal viscoelastic creep data and improve the accuracy of the test. Description of the Drawings

[0024] In order to make the content of the invention easier to be clearly understood, the following further details the invention according to the specific embodiments of the invention and in combination with the drawings, wherein:

[0025] Figure 1 It is a schematic structural diagram of an instrument for accurately testing the viscoelastic parameters of optical glass materials in a preferred embodiment of the present invention;

[0026] Figure 2 is Figure 1 A schematic structural diagram of the instrument for accurately testing the viscoelastic parameters of optical glass materials in the test state shown;

[0027] Figure 3 It is a schematic diagram of the step force load F of the electromagnetic inductor on the lower pressing block downward;

[0028] Figure 4 is using Figure 1 A flowchart of the test using the instrument for accurately testing the viscoelastic parameters of optical glass materials shown;

[0029] Figure 5 is the traditional axial creep test and the micro axial creep test;

[0030] Figure 6 is the axial creep displacement simulation nephogram at each temperature (where Figure 6 (a) is the axial creep displacement simulation nephogram at 550 °C, Figure 6 (b) is the axial creep displacement simulation nephogram at 600 °C);

[0031] Figure 7 is the comparison between the numerical simulation results and the measured results at different temperatures (where Figure 7 (a) is the comparison between the numerical simulation results and the measured results at 550 °C, Figure 7 (b) is the comparison between the numerical simulation results and the measured results at 600 °C).

[0032] Explanation of the reference numerals in the drawings: 100, frame; 110, column; 120, base; 130, top plate;

[0033] 200, Working chamber; 210, Sealed cavity; 220, Heating element; 230, Sample holder; 240, Force sensor; 250, Guide; 260, Cover plate;

[0034] 300, Displacement detection assembly; 310, Displacement sensor; 311, Detection body; 312, Sensor connecting rod; 320, Cover;

[0035] 400, Force module; 410, Lifting bracket; 420, Electromagnetic inductor; 430, Pressing block; 440, Pressure ejector rod; 450, Elastic rod; 460, Slide block;

[0036] 500, Sample;

[0037] 600, Spacer. Specific embodiments

[0038] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited are not intended to limit the present invention.

[0039] The viscoelastic properties of glass within the forming temperature range, such as the shear relaxation modulus, are key physical quantities for predicting the fluidity and stress relaxation behavior of glass during the molding process. However, it is difficult to obtain high-precision glass viscoelastic data using traditional large axial creep testing methods because during the testing process, the cross-sectional area of the specimen continuously increases and the side expands into a drum shape under the interference of interfacial friction, resulting in distorted creep data. In addition, existing calculation methods have limitations in converting axial creep data into viscoelastic shear relaxation modulus. Especially when the Poisson's ratio of glass is unknown at high temperatures, it will lead to the inability to calculate viscoelasticity. For this reason, in this embodiment, a certain optical glass is taken as the specific research object, and a viscoelastic testing method based on micro axial creep is proposed to accurately obtain the viscoelastic data of glass, specifically including micro axial creep testing, short-term modulus testing, viscoelastic characterization calculation, and finite element analysis verification.

[0040] To address the above problems, refer to Figures 1 to 7As shown in the figure, the embodiment of the present invention provides an instrument and a method for accurately testing the viscoelastic parameters of optical glass materials. The instrument for accurately testing the viscoelastic parameters of optical glass materials includes a frame 100, a working chamber 200, a displacement detection component 300, and a force module 400. The frame 100 includes columns 110; the working chamber 200 includes a sealed cavity 210 provided on one side of the column 110, heating elements 220 provided around the sealed cavity 210, a sample holder 230, and a force sensor 240; both the sample holder 230 and the force sensor 240 are arranged in the sealed cavity 210, and the force sensor 240 is arranged at the bottom of the sample holder 230 to measure the contact force. During operation, the pressure borne by the sample 500 can be transmitted to the force sensor 240 through the sample holder 230. Thus, it is ensured that the sample 500 does not deform under the initial test conditions, and the pressure value applied by the force module 400 to the sample 500 can be detected in real time during the test process. The force module 400 includes a first driving member, a lifting bracket 410 slidably connected to the column 110, an electromagnetic inductor 420 arranged on the lifting bracket 410, a pressing block 430 forming a rotating pair with the outer end of the lifting bracket 410, and a pressure ejector rod 440 arranged at the bottom of the pressing block 430. In some embodiments, the pressing block 430 is connected to the outer end of the lifting bracket 410 through an elastic rod 450. One end of the elastic rod 450 is connected to the outer end of the lifting bracket 410, and the other end of the elastic rod 450 is connected to the end of the pressing block 430 far from the pressure ejector rod 440. In other embodiments, the outer end of the lifting bracket 410 is hinged to the end of the pressing block 430 far from the pressure ejector rod 440. The pressing block 430 is arranged in parallel with the side of the lifting bracket 410 where the electromagnetic inductor 420 is arranged; the lifting bracket 410 can move up and down to drive the pressure ejector rod 440 to contact and fix the sample 500. After the electromagnetic inductor 420 is powered on, it can provide a downward step force for the pressing block 430 and the pressure ejector rod 440; the electromagnetic inductor 420 can generate an ideal step force and ensure the accuracy of the step force load, so that the sample 500 does not generate a drum shape.

[0041] The displacement detection component 300 includes a displacement sensor 310 arranged on the top of the pressing block 430, and the displacement sensor 310 is used to monitor the axial deformation of the sample 500 after being stressed.

[0042] The following steps are carried out by using the instrument in the above embodiment: the lifting bracket 410 descends until the pressure ejector rod 440 contacts the upper surface of the sample 500; the electromagnetic inductor 420 is powered on to provide a downward step force for the pressing block 430. The step force is applied to the sample 500 to cause the sample 500 to deform. At the same time, the force sensor 240 monitors the value of the step force applied to the sample 500, and the displacement sensor 310 monitors the axial deformation of the sample 500 after being stressed. For the specific test operation process, please refer to Figure 4 .

[0043] Test Example 1

[0044] In this test example, the viscoelasticity of cylindrical Borofloat-33 optical glass was tested at a temperature of 550 °C using the described instrument and method, and the viscoelastic shear relaxation modulus of this type of optical glass was obtained. During the test, the glass sample 500 was heated to 550 °C and then held for 10 minutes to ensure a uniform temperature distribution in the sample. Subsequently, the sensor connecting rod 312 applied a step load of 1 N to the sample, and while maintaining the temperature, the axial creep data of the glass sample 500 was recorded by the LVDT displacement sensor 310. The axial creep data of the glass sample was then converted into the viscoelastic shear relaxation modulus of the glass through the following solution process to complete the calculation of the glass viscoelasticity data.

[0045] First, the axial creep compliance obtained from the test was fitted using the generalized Kelvin model: For fitting:

[0046] (1)

[0047] In formula (1), t is time; is the short-term Young's modulus at a specific temperature; and are the elastic modulus and relaxation time of the th unit of the generalized Kelvin model respectively; represents the viscosity of the dashpot unit in series with the Kelvin model.

[0048] Taking the Laplace transform of formula (1), we get :

[0049] (2)

[0050] In formula (2), s is the independent variable in the Laplace domain; is the short-term Young's modulus at a specific temperature; and are the elastic modulus and relaxation time of the th unit of the generalized Kelvin model respectively; represents the viscosity of the dashpot unit in series with the Kelvin model.

[0051] Furthermore, the shear relaxation modulus in the Laplace domain can be calculated by formula (3):

[0052] (3)

[0053] In formula (3), is the shear relaxation modulus The form after Laplace transform; s is the independent variable in the Laplace domain; is the short-term Young's modulus at a specific temperature; and are the elastic modulus and relaxation time of the th unit of the generalized Kelvin model respectively; represents the viscosity of the dashpot unit in series with the Kelvin model.

[0054] Performing the inverse Laplace transform on the complex shear relaxation modulus in formula (3) to obtain the shear relaxation modulus data in the time domain, and using the four-unit generalized Maxwell model to fit the shear relaxation modulus data in the time domain, and obtaining the component data of the viscoelastic shear relaxation modulus of the glass material at 550 °C as follows:

[0055] (4)

[0056] In formula (4), t is time; is the relaxation time of the th branch of the generalized Maxwell model, , is determined jointly by the shear modulus of the th Maxwell unit and the viscosity of the th Maxwell unit.

[0057] Establishing a numerical simulation model of the test process, here an axisymmetric finite element simulation model, and inputting the component data of the viscoelastic shear relaxation modulus of the glass material at 550 °C obtained by the said test and calculation method into the simulation model, performing simulation and obtaining the axial creep displacement (unit: mm) of the model, as Figure 6 (a) shows. It is found that the creep displacement contour map is a uniform layered distribution, avoiding the non-uniform axial creep displacement distribution caused by the side bulging in the traditional axial creep simulation, indicating that the said method can achieve ideal axial creep; extracting the simulation results and comparing them with the experimental results, the simulation creep curve and the experimental creep curve are highly consistent, with the maximum deviation within 0.1%, as Figure 7 (a) shows, further indicating that the said method can be used as a high-precision viscoelastic testing method.

[0058] In this test example, the viscoelasticity of cylindrical Borofloat-33 optical glass is tested at a temperature of 600 °C by means of the described instrument and method. During the test, the glass sample 500 is heated to 600 °C and then kept warm for 10 minutes to ensure a uniform temperature distribution of the sample. Subsequently, the sensor connecting rod 312 applies a step load of 1 N to the sample, and while keeping warm, the axial creep data of the glass sample 500 is recorded by the LVDT displacement sensor 310. And through the following solution process, the axial creep data of the glass sample is converted into the viscoelastic shear relaxation modulus of the glass to complete the calculation of the glass viscoelasticity data.

[0059] The axial creep compliance obtained from the test is fitted through the generalized Kelvin model as follows:

[0060] (5)

[0061] In formula (5), t is time; is the short-term Young's modulus at a specific temperature; and are respectively the elastic modulus and relaxation time of the th unit of the generalized Kelvin model; represents the viscosity of the dashpot unit in series with the Kelvin model.

[0062] Performing the Laplace transform on formula (5), we get :

[0063] (6)

[0064] In formula (6), s is the independent variable in the Laplace domain; is the short-term Young's modulus at a specific temperature; and are respectively the elastic modulus and relaxation time of the th unit of the generalized Kelvin model; represents the viscosity of the dashpot unit in series with the Kelvin model.

[0065] Furthermore, the shear relaxation modulus in the complex domain can be calculated by formula (6):

[0066] (7)

[0067] In formula (7), is the form of the shear relaxation modulus after the Laplace transform; s is the independent variable in the Laplace domain; is the short-term Young's modulus at a specific temperature; and are the elastic modulus and relaxation time of the th unit of the generalized Kelvin model, respectively; represents the viscosity of the viscous pot unit connected in series with the Kelvin model.

[0068] Performing the inverse Laplace transform on the shear relaxation modulus in the complex domain in formula (7) to obtain the shear relaxation modulus in the time domain. The data is then fitted with a four-unit generalized Maxwell model for the shear relaxation modulus in the time domain, and the component data of the viscoelastic shear relaxation modulus of the glass material at 600 °C is obtained as follows:

[0069] (8)

[0070] In formula (8), t is time; is the relaxation time of the th branch of the generalized Maxwell model, , is determined jointly by the shear modulus of the th Maxwell unit and the viscosity of the th Maxwell unit.

[0071] A numerical simulation model of the test process is established, which is an axisymmetric finite element simulation model here. The component data of the viscoelastic shear relaxation modulus of the glass material at 600 °C obtained by the above test and calculation method is input into the simulation model, and the axial creep displacement (unit: mm) of the model is obtained by simulating. As Figure 6 (b) shows, it is found that the creep displacement contour map is a uniform layered distribution, avoiding the non-uniform axial creep displacement distribution caused by the side bulging in the traditional axial creep simulation, indicating that the method can achieve ideal axial creep; the simulation results are extracted and compared with the experimental results. The simulation creep curve and the experimental creep curve are highly consistent, with a maximum deviation within 0.1%. As Figure 7 (b) shows, further indicating that the method can be used as a high-precision viscoelastic testing method.

[0072] Specifically, this embodiment can achieve an ideal step force and meet more ideal creep test load conditions. During the test, only axial creep deformations of a few micrometers to dozens of micrometers occur, and no obvious bulging occurs on the side, thereby ensuring a constant pressure and weakening the interference of friction, thus ensuring the acquisition of ideal viscoelastic creep data and improving the accuracy of the test.

[0073] Further, the present application further includes a control component, which is electrically connected to the heating element 220, the force sensor 240, the electromagnetic inductor 420, and the first driving member. The control component can control the heating rate of the heating chamber by controlling the current of the heating element 220.

[0074] Specifically, under the initial test conditions, the control component controls the first driving member to start and drive the lifting bracket 410 to descend so that the pressure ejector rod 440 contacts the sample 500. At the same time, the force sensor 240 can monitor the pressure applied by the force module 400 to the sample 500 and feedback it to the control component, so as to ensure that the sample 500 does not deform under the initial test conditions. During the test, the control component controls the electromagnetic inductor 420 to start and apply pressure to the sample 500. At the same time, the force sensor 240 can monitor the pressure applied by the force module 400 to the sample 500 and feedback it to the control component, so as to monitor the pressure value applied by the force module 400 to the sample 500 in real time. During the deformation of the sample 500, the displacement of the sample 500 can be detected by the displacement sensor 310, and this information is transmitted to the control component. Thus, it can be seen that this embodiment can further achieve precise testing and automation.

[0075] Further, the frame 100 further includes a base 120 fixedly connected to the bottom of the column 110 and a top plate 130 fixedly connected to the top of the column 110. The working chamber 200 is arranged on the base 120. Specifically, the structure of the frame 100 in this embodiment is more stable and reliable.

[0076] Further, the displacement sensor 310 adopts an LVDT displacement sensor 310. Specifically, the LVDT displacement sensor 310 is small in volume and light in weight, and can accurately measure the deformation of the sample 500 to achieve nanometer-level high-precision deformation measurement.

[0077] Further, the displacement sensor 310 includes a detection body 311 connected to the top plate 130 of the frame 100 and a sensor connecting rod 312 arranged at the bottom of the detection body 311; the displacement detection assembly 300 further includes a cover body 320, the cover body 320 is arranged on the top of the top plate 130, the detection body 311 is located in the cover body 320, the top plate 130 is provided with a first through hole, and the sensor connecting rod 312 passes through the first through hole of the top plate 130 and then is connected to the lower pressing block 430. Specifically, since the displacement sensor 310 needs to achieve nanometer-level high-precision deformation measurement, the detection body 311 and part of the sensor connecting rod 312 are arranged in the cover body 320, so as to avoid the influence of external environmental factors on the accuracy of the displacement sensor 310 and further ensure the accuracy of the test.

[0078] Further, the working chamber 200 further includes a guiding member 250 and a cover plate 260. The heating member 220 is slidably connected to the outer wall of the guiding member 250. After the heating member 220 rises, a sealed cavity 210 is formed by enclosing the cover plate 260 and the guiding member 250. The cover plate 260 is connected to one side of the column 110. The cover plate 260 is provided with a second through hole, and the pressure ejector rod 440 passes through the second through hole and extends into the sealed cavity 210. Specifically, in this embodiment, the heating member 220 can be slidably connected to the outer wall of the guiding member 250, so as to facilitate the placement and removal of the sample 500 while ensuring the formation of the sealed cavity 210 during the test.

[0079] Further, the heating member 220 is an infrared heating tube. Specifically, the infrared heating tube uses the heating method of thermal radiation. In this way, when the heating member 220 heats the sample 500, only the sample 500 is heated, and the heating temperature of the space of the sealed cavity 210 is lower than the heating temperature of the sample 500, so as to avoid the test result distortion caused by the influence of the temperature of the space of the sealed cavity 210 on the force sensor 240, and further improve the accuracy of the test.

[0080] Further, the sample holder 230 is made of quartz glass. Specifically, on the one hand, the quartz glass sample holder 230 can isolate the temperature transfer of the sample 500 to the force sensor 240, thus protecting the force sensor 240. On the other hand, the quartz glass sample holder 230 is transparent, so that the heat of the heating device can pass through the sample holder 230 and be transferred to the sample 500, thereby ensuring that the temperature of the sample 500 is more uniform.

[0081] Further, one end of the lifting bracket 410 connected to the column 110 is provided with a slider 460. The slider 460 is sleeved on the column 110. The slider 460 is connected to the first driving member, and the first driving member drives the slider 460 to move up and down along the column 110. In some embodiments, the first driving member is an oil cylinder, a cylinder or an electric cylinder body and other structures capable of realizing linear motion. Specifically, in this embodiment, the first driving member drives the slider 460 to realize the lifting of the lifting bracket 410, and the structure is simple and the operation is stable and reliable.

[0082] Further, the working chamber 200 further includes a lifting cylinder body. The telescopic end of the lifting cylinder body is connected to the heating member 220, and the lifting and telescoping of the lifting cylinder body drives the heating member 220 to lift. The working chamber 200 further includes a guide rail provided on the outer wall of the guiding member 250 and a slider cooperating with the guide rail. The slider is connected to the inner wall of the heating member 220.

[0083] Further, the present application further includes a gasket 600. The gasket 600 is provided between the sample holder 230 and the sample 500, and the gasket 600 is also provided on the upper surface of the sample 500.

[0084] This method takes glass as the specific research object and proposes a viscoelastic calculation method based on micro axial creep to accurately obtain the viscoelastic data of glass, specifically including micro axial creep test, short-term modulus test, viscoelastic characterization calculation and finite element analysis verification.

[0085] This application avoids the limitations of the existing calculation methods in converting axial creep data into viscoelastic shear relaxation modulus. Especially when the Poisson's ratio of glass is unknown at high temperatures, the viscoelasticity cannot be calculated.

[0086] Obviously, the above embodiments are only examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the invention.

Claims

1. An instrument for accurately testing the viscoelastic parameters of optical glass materials, characterized by: include: A rack, including uprights; A working chamber, comprising a sealed chamber disposed on one side of the column, a heating element disposed around the sealed chamber, a sample holder and a force sensor; the sample holder and the force sensor are both disposed in the sealed chamber, and the force sensor is disposed at the bottom of the sample holder; The force module comprises a first driving member, a lifting bracket slidably connected to the column, an electromagnetic inductor arranged on the lifting bracket, a lower pressing block forming a rotating pair with the outer end of the lifting bracket, and a pressure push rod arranged at the bottom of the lower pressing block; the lower pressing block is arranged in parallel to a side of the lifting bracket on which the electromagnetic inductor is arranged; the lower pressing block is connected to the lifting bracket through an elastic rod, the lifting bracket can be lifted up and down to drive the pressure push rod to contact the sample, and the electromagnetic inductor can provide a downward step force for the lower pressing block and the pressure push rod after being energized; The displacement detection component comprises a displacement sensor arranged on the top of the lower pressing block, and the displacement sensor is used to monitor the axial deformation of the sample after being subjected to force.

2. The instrument for accurately testing the viscoelastic parameters of optical glass materials according to claim 1, characterized in that: It also includes a control component, which is electrically connected to the heating element, the force sensor, the electromagnetic inductor and the first driving element.

3. The instrument for accurately testing the viscoelastic parameters of optical glass materials according to claim 1, characterized in that: The frame also includes a base fixedly connected to the bottom of the column and a top plate fixedly connected to the top of the column, and the working chamber is arranged on the base.

4. The instrument for accurately testing viscoelastic parameters of optical glass materials according to claim 3, characterized in that: The displacement sensor includes a detection body connected to the frame and a sensor connecting rod arranged at the bottom of the detection body; the displacement detection assembly also includes a cover body, which is arranged on the top of the top plate, and the sensor connecting rod passes through the first through hole of the top plate and is connected to the lower pressure block.

5. The instrument for accurately testing viscoelastic parameters of optical glass materials according to claim 3, characterized in that: The working chamber also includes a guide member and a cover plate. The heating member is slidably connected to the outer wall of the guide member up and down. After the heating member rises, it is surrounded by the cover plate and the guide member to form a closed cavity. The cover plate is connected to one side of the column. The cover plate is provided with a second through hole. The pressure push rod passes through the second through hole and extends into the closed cavity.

6. The instrument for accurately testing viscoelastic parameters of optical glass materials according to claim 5, characterized in that: The working chamber further comprises a lifting cylinder, the telescopic end of which is connected to the heating element, and the lifting cylinder drives the heating element to rise and fall when the lifting cylinder is telescopically extended.

7. The instrument for accurately testing viscoelastic parameters of optical glass materials according to claim 6, characterized in that: The working chamber further comprises a guide rail arranged on the outer wall of the guide member and a slider matched with the guide rail, and the slider is connected to the inner wall of the heating member.

8. The instrument for accurately testing viscoelastic parameters of optical glass materials according to claim 1, characterized in that: The heating element is an infrared heating tube.

9. The instrument for accurately testing viscoelastic parameters of optical glass materials according to claim 1, characterized in that: A slider is provided at one end of the lifting bracket connected to the column. The slider is sleeved on the column and connected to the first driving member. The first driving member drives the slider to move up and down along the column.

10. A method for accurately testing the viscoelastic parameters of optical glass materials, characterized by: The following steps are carried out using any one of claims 1 to 9: The lifting bracket descends until the pressure push rod contacts the upper surface of the sample; the electromagnetic sensor is energized to provide a downward step force for the lower pressure block, and the step force is applied to the sample to deform the sample. At the same time, the force sensor monitors the value of the step force applied to the sample, and the displacement sensor monitors the axial deformation of the sample after the force is applied.

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