Instrument and method for accurately testing viscoelastic parameters of optical glass material

Abstract

The invention relates to the technical field of material viscoelasticity testing, and provides an instrument and a method for accurately testing viscoelasticity parameters of an optical glass material. The invention comprises: a frame; the working cavity comprises a closed cavity body, heating pieces arranged at the periphery of the closed cavity body, a sample bracket and a force sensor; the sample bracket and the force sensor are arranged in the closed cavity; the force module comprises a lifting support, an electromagnetic inductor, a lower pressing block and a pressure ejector rod. The lower pressing block is arranged on the side, provided with the electromagnetic inductor, of the lifting support in parallel. The lifting support can lift up and down to drive the pressure ejector rod to make contact with a sample, and the electromagnetic inductor can provide downward step force for the lower pressing block and the pressure ejector rod after being powered on. The displacement detection assembly comprises a displacement sensor used for monitoring axial deformation of the sample after the sample is stressed. According to the invention, ideal step force can be realized, and more ideal creep test load conditions can be met; the acquisition of ideal viscoelastic creep data is ensured, and the test accuracy is improved.

Description

Technical Field

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

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

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

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

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

[0006] In order to solve the above technical problems, on the one hand, the present invention provides an instrument for accurately testing the viscoelastic parameters of optical glass materials, comprising: A rack, including uprights; The working chamber comprises 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 parallel to a side of the lifting bracket where the electromagnetic inductor is arranged; 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 includes 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.

[0007] In one embodiment of the invention, the present application further includes a control component, which is electrically connected to the heating element, the force sensor, the electromagnetic inductor and the first driving element.

[0008] In one embodiment of the invention, the frame further comprises 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.

[0009] 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 also includes a cover body, the cover body 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.

[0010] In one embodiment of the invention, the working chamber also includes a guide member and a cover plate, the heating member is slid up and down and connected to the outer wall of the guide member, and 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, and the cover plate is provided with a second through hole, and the pressure push rod passes through the second through hole and extends into the closed cavity.

[0011] In one embodiment of the invention, the working chamber further comprises a lifting cylinder, the telescopic end of the lifting cylinder is connected to the heating element, and the lifting cylinder telescopes to drive the heating element to rise and fall.

[0012] In one embodiment of the invention, 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.

[0013] In one embodiment of the invention, the heating element is an infrared heating tube.

[0014] In one embodiment of the invention, the sample holder is made of quartz glass.

[0015] In one embodiment of the invention, 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 a first driving member. The first driving member drives the slider to move up and down along the column.

[0016] On the other hand, the present invention provides a method for accurately testing the viscoelastic parameters of optical glass materials, using any of the above embodiments to perform the following steps: 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 to 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.

[0017] The above technical solution of the invention has the following beneficial effects compared with the prior art: The instrument and method for accurately testing the viscoelastic parameters of optical glass materials described in the present invention can achieve an ideal step force and meet more ideal creep test load conditions. During the test, only a few microns to tens of microns of axial creep deformation occur, and no obvious drum shape is produced on the side, thereby ensuring constant pressure and reducing the interference of friction, thereby ensuring the acquisition of ideal viscoelastic creep data and improving the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the content of the invention more clearly understood, the invention is further described in detail below based on specific embodiments of the invention in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of an instrument for accurately testing the viscoelastic parameters of optical glass materials in a preferred embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the structure of an instrument for accurately testing the viscoelastic parameters of optical glass materials under a testing state is shown; Figure 3 It is a schematic diagram of the step force load F exerted downward by the electromagnetic inductor on the lower pressing block; Figure 4 To use Figure 1 A flow chart of a test performed by an instrument for accurately testing viscoelastic parameters of optical glass materials is shown; Figure 5 It is a traditional axial creep test and a micro axial creep test; Figure 6 is the axial creep displacement simulation cloud diagram at each temperature (where Figure 6 (a) is the axial creep displacement simulation cloud diagram at 550℃. Figure 6 (b) is the axial creep displacement simulation cloud diagram at 600℃); Figure 7 Comparison of numerical simulation results with 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) Comparison between numerical simulation results and measured results at 600°C).

[0019] Description of the accompanying drawings: 100, frame; 110, column; 120, base; 130, top plate; 200, working chamber; 210, sealed chamber; 220, heating element; 230, sample holder; 240, force sensor; 250, guide element; 260, cover plate; 300, displacement detection assembly; 310, displacement sensor; 311, detection body; 312, sensor connecting rod; 320, cover body; 400, force module; 410, lifting bracket; 420, electromagnetic inductor; 430, lower pressing block; 440, pressure push rod; 450, elastic rod; 460, slider; 500, samples; 600. Gasket. DETAILED DESCRIPTION

[0020] The invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the invention and implement it, but the embodiments are not intended to limit the invention.

[0021] The viscoelastic properties of glass within the molding temperature range, such as shear relaxation modulus, are key physical quantities for predicting the fluidity and stress relaxation behavior of glass during the molding process. However, the traditional large axial creep test method is difficult to obtain high-precision viscoelastic data of glass. This is because during the test, the cross-sectional area of ​​the sample continues to increase and the side expands into a drum shape under the interference of interface friction, which leads to distortion of creep data. In addition, the existing calculation method has limitations in converting axial creep data into viscoelastic shear relaxation modulus, especially when the Poisson's ratio of the glass is unknown at high temperatures, which will lead to the inability to calculate viscoelasticity. To this end, this embodiment takes a certain optical glass as a specific research object, and proposes a viscoelastic test 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.

[0022] For the above problems, refer to Figure 1 to Figure 7As shown, the embodiment of the present invention provides an instrument and 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 assembly 300, and a force module 400. The frame 100 includes a column 110; the working chamber 200 includes a closed chamber 210 disposed on one side of the column 110, a heating element 220 disposed around the closed chamber 210, a sample holder 230, and a force sensor 240; the sample holder 230 and the force sensor 240 are both disposed in the closed chamber 210, and the force sensor 240 is disposed 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. Thereby, it is ensured that the sample 500 does not deform under the initial test conditions, and the pressure value applied to the sample 500 by the force module 400 can be detected in real time during the test. The force module 400 includes a first driving member, a lifting bracket 410 slidably connected to the column 110, an electromagnetic inductor 420 disposed on the lifting bracket 410, a lower pressing block 430 forming a rotating pair with the outer end of the lifting bracket 410, and a pressure push rod 440 disposed at the bottom of the lower pressing block 430. In some embodiments, the lower 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 an end of the lower pressing block 430 away from the pressure push rod 440. In other embodiments, the outer end of the lifting bracket 410 is hinged to an end of the lower pressing block 430 away from the pressure push rod 440. The lower pressing block 430 is arranged in parallel to one side of the lifting bracket 410 on which the electromagnetic inductor 420 is arranged; the lifting bracket 410 can be lifted up and down to drive the pressure push rod 440 to contact and fix with the sample 500, and the electromagnetic inductor 420 can provide a downward step force for the lower pressing block 430 and the pressure push rod 440 after being energized; the electromagnetic inductor 420 can generate an ideal step force and ensure the accuracy of the step force load, thereby preventing the sample 500 from producing a bulging shape.

[0023] The displacement detection assembly 300 includes a displacement sensor 310 disposed on the top of the lower pressing block 430 . The displacement sensor 310 is used to monitor the axial deformation of the sample 500 after being subjected to force.

[0024] The following steps are performed using the instrument in the above embodiment: the lifting bracket 410 is lowered until the pressure push rod 440 contacts the upper surface of the sample 500; the electromagnetic inductor 420 is energized to provide a downward step force for the lower pressing block 430, and the step force is applied to the sample 500 to deform the sample 500. 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 the force is applied. For the specific test operation process, see Figure 4 .

[0025] Test Example 1 In this test example, the viscoelasticity test of cylindrical Borofloat-33 optical glass at 550°C was performed by the instrument and method, and the viscoelastic shear relaxation modulus of this type of optical glass was obtained. During the test, the glass sample 500 is heated to 550°C and then kept warm for 10 minutes to ensure uniform temperature distribution of the sample. Subsequently, the sensor connecting rod 312 applies a step load of 1N to the sample, keeps warm, and records the axial creep data of the glass sample 500 through the LVDT displacement sensor 310. The axial creep data of the glass sample is converted into the viscoelastic shear relaxation modulus of the glass through the following solution process to complete the calculation of the viscoelastic data of the glass.

[0026] First, the axial creep compliance obtained by the test is calculated using the generalized Kelvin model. Perform the fit: (1) In formula (1), t For time; is the short-term Young's modulus at a specific temperature; and The generalized Kelvin model is Elastic modulus and relaxation time of each unit; represents the viscosity of the viscometer unit in series with the Kelvin model.

[0027] Performing Laplace transform on formula (1), we get : (2) In formula (2), s is the independent variable of the Laplace domain; is the short-term Young's modulus at a specific temperature; and The generalized Kelvin model is Elastic modulus and relaxation time of each unit; represents the viscosity of the viscometer unit in series with the Kelvin model.

[0028] Furthermore, the shear relaxation modulus in the Laplace domain is It can be calculated by formula (3): (3) In formula (3), is the shear relaxation modulus The form after Laplace transformation; s is the independent variable of Laplace domain; is the short-term Young's modulus at a specific temperature; and The generalized Kelvin model is Elastic modulus and relaxation time of each unit; represents the viscosity of the viscometer unit in series with the Kelvin model.

[0029] The shear relaxation modulus in the complex domain of formula (3) is Perform an inverse Laplace transform to obtain the shear relaxation modulus in the time domain The data were fitted with a four-element generalized Maxwell model to fit the shear relaxation modulus in the time domain. The data of each component of the viscoelastic shear relaxation modulus of the glass material at 550°C are obtained as follows: (4) In formula (4), t For time; For the generalized Maxwell model The relaxation time of each branch, , By Shear modulus of a Maxwell element and Viscosity in Maxwell units Determined jointly.

[0030] A numerical simulation model of the test process is established, which is an axisymmetric finite element simulation model. The viscoelastic shear relaxation modulus component data of the glass material at 550°C obtained by the test and calculation method is input into the simulation model, and the axial creep displacement (unit: mm) of the model is obtained by simulation. Figure 6 As shown in (a), the creep displacement cloud diagram is found to be uniformly layered, which avoids the non-uniform axial creep displacement distribution caused by the side drum 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 is highly consistent with the experimental creep curve, with a maximum deviation of less than 0.1%. Figure 7 As shown in (a), it is further illustrated that the method can be used as a high-precision viscoelasticity testing method.

[0031] In this test example, the viscoelastic test of cylindrical Borofloat-33 optical glass at 600°C was performed by the instrument and method. During the test, the glass sample 500 was heated to 600°C and then kept warm for 10 minutes to ensure uniform temperature distribution of the sample. Subsequently, the sensor connecting rod 312 applied a step load of 1N to the sample, kept warm, and recorded the axial creep data of the glass sample 500 through the LVDT displacement sensor 310. The axial creep data of the glass sample was converted into the viscoelastic shear relaxation modulus of the glass through the following solution process to complete the calculation of the viscoelastic data of the glass.

[0032] Axial creep compliance measured by the generalized Kelvin model Perform the fit: (5) In formula (5), t For time; is the short-term Young's modulus at a specific temperature; and The generalized Kelvin model is Elastic modulus and relaxation time of each unit; represents the viscosity of the viscometer unit in series with the Kelvin model.

[0033] Performing Laplace transform on formula (5), we get : (6) In formula (6), s is the independent variable of the Laplace domain; is the short-term Young's modulus at a specific temperature; and The generalized Kelvin model is Elastic modulus and relaxation time of each unit; represents the viscosity of the viscometer unit in series with the Kelvin model.

[0034] Furthermore, the shear relaxation modulus in the complex domain is It can be calculated by formula (6): (7) In formula (7), is the shear relaxation modulus The form after Laplace transformation; s is the independent variable of Laplace domain; is the short-term Young's modulus at a specific temperature; and The generalized Kelvin model is Elastic modulus and relaxation time of each unit; represents the viscosity of the viscometer unit in series with the Kelvin model.

[0035] The shear relaxation modulus in the complex domain of formula (7) is Perform an inverse Laplace transform to obtain the shear relaxation modulus in the time domain The data were fitted with a four-element generalized Maxwell model to fit the shear relaxation modulus in the time domain. The data of each component of the viscoelastic shear relaxation modulus of the glass material at 600°C are obtained as follows: (8) In formula (8), t For time; For the generalized Maxwell model The relaxation time of each branch, , By Shear modulus of a Maxwell element and Viscosity in Maxwell units Determined jointly.

[0036] A numerical simulation model of the test process is established, which is an axisymmetric finite element simulation model. The viscoelastic shear relaxation modulus component data of the glass material at 600°C obtained by the test and calculation method is input into the simulation model, and the axial creep displacement (unit: mm) of the model is obtained by simulation. Figure 6 As shown in (b), the creep displacement cloud diagram is found to be uniformly layered, which avoids the non-uniform axial creep displacement distribution caused by the side drum 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 is highly consistent with the experimental creep curve, with a maximum deviation of less than 0.1%. Figure 7 As shown in (b), it further illustrates that the method can be used as a high-precision viscoelasticity testing method.

[0037] Specifically, this embodiment can achieve an ideal step force and meet more ideal creep test load conditions. During the test, only a few microns to tens of microns of axial creep deformation occur, and no obvious drum shape is produced on the side, thereby ensuring constant pressure and reducing the interference of friction, thereby ensuring the acquisition of ideal viscoelastic creep data and improving the accuracy of the test.

[0038] Furthermore, the present application also 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 element. The control component can control the heating rate of the heating chamber by controlling the current of the heating element 220.

[0039] 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 push rod 440 contacts the sample 500. At the same time, the force sensor 240 can monitor the pressure applied to the sample 500 by the force module 400 and feed it back to the control component, thereby ensuring 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 applying pressure to the sample 500. At the same time, the force sensor 240 can monitor the pressure applied to the sample 500 by the force module 400 and feed it back to the control component, thereby monitoring the pressure value applied to the sample 500 by the force module 400 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 the information is transmitted to the control component. It can be seen that this embodiment can further achieve precise testing and automation.

[0040] Furthermore, 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, and the working chamber 200 is disposed on the base 120. Specifically, the structure of the frame 100 of this embodiment is more stable and reliable.

[0041] Furthermore, the displacement sensor 310 uses an LVDT displacement sensor 310. Specifically, the LVDT displacement sensor 310 is small in size and light in weight, and can accurately measure the deformation of the sample 500, thereby achieving nanometer-level high-precision deformation measurement.

[0042] Furthermore, 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 also includes a cover 320, the cover 320 is arranged on the top of the top plate 130, the detection body 311 is located in the cover 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 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 320, so as to avoid external environmental factors affecting the accuracy of the displacement sensor 310, and further ensure the accuracy of the test.

[0043] Furthermore, the working chamber 200 further includes a guide member 250 and a cover plate 260, the heating member 220 is slidably connected to the outer wall of the guide member 250, and after the heating member 220 rises, it is surrounded by the cover plate 260 and the guide member 250 to form a closed chamber 210; the cover plate 260 is connected to one side of the column 110, and the cover plate 260 is provided with a second through hole, and the pressure push rod 440 passes through the second through hole and extends into the closed chamber 210. Specifically, the heating member 220 in this embodiment can be slidably connected to the outer wall of the guide member 250, so as to facilitate the taking and placing of the sample 500 while ensuring that the closed chamber 210 is formed during the test.

[0044] Furthermore, the heating element 220 is an infrared heating tube. Specifically, the infrared heating tube is a heating method of thermal radiation, so when the heating element 220 heats the sample 500, it will only heat the sample 500, and the heating temperature of the space of the closed cavity 210 is lower than the heating temperature of the sample 500, thereby preventing the force sensor 240 from being affected by the temperature of the space of the closed cavity 210 and causing distortion of the test result, further improving the accuracy of the test.

[0045] Furthermore, the sample holder 230 is made of quartz glass. Specifically, the sample holder 230 made of quartz glass can, on the one hand, isolate the temperature of the sample 500 from being transferred to the force sensor 240, thereby protecting the force sensor 240. On the other hand, the sample holder 230 made of quartz glass 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.

[0046] Furthermore, a slider 460 is provided at one end of the lifting bracket 410 connected to the column 110. The slider 460 is sleeved on the column 110. The slider 460 is connected to a 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 a cylinder, a gas cylinder, or an electric cylinder or other structure capable of realizing linear motion. Specifically, in this embodiment, the lifting bracket 410 is lifted and lowered by driving the slider 460 through the first driving member, and the structure is simple and the operation is stable and reliable.

[0047] Furthermore, the working chamber 200 further includes a lifting cylinder, the telescopic end of which is connected to the heating element 220, and the extension of the lifting cylinder drives the heating element 220 to rise and fall. The working chamber 200 further includes a guide rail provided on the outer wall of the guide element 250 and a slider matched with the guide rail, and the slider is connected to the inner wall of the heating element 220.

[0048] Furthermore, the present application also includes a gasket 600 , which is disposed between the sample holder 230 and the sample 500 , and the gasket 600 is also disposed on the upper surface of the sample 500 .

[0049] 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, which specifically includes micro-axial creep test, short-term modulus test, viscoelastic characterization calculation and finite element analysis verification.

[0050] The present application avoids the limitations of existing calculation methods in converting axial creep data into viscoelastic shear relaxation modulus, especially when the glass Poisson's ratio is unknown at high temperatures and the viscoelasticity cannot be calculated.

[0051] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled 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 methods here. The obvious changes or modifications derived from these are still within the scope of protection 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 where the electromagnetic inductor is arranged; 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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