A rubber stress relaxation in-situ test monitoring device, test method and monitoring method

Abstract

The present invention discloses an in-situ test monitoring device, test method and monitoring method for rubber stress relaxation, wherein a rubber sample installation portion is arranged at the periphery of the central area at the top of a heat-insulating shell, the rubber sample installation portion is connected to a rubber compression control mechanism located in the heat-insulating shell, a visual terminal is arranged at the central area at the top of the heat-insulating shell, the visual terminal is arranged in a quartz glass cover, and the visual terminal is used to photograph the rubber sample; the steps of the test method and the monitoring method include: firstly controlling the visual terminal to photograph the rubber sample in a non-compressed state, then controlling the operation of the rubber compression control mechanism to move its telescopic rod upward, and photographing the rubber sample in a compressed state in real time during the process. The present invention realizes in-situ monitoring of the stress relaxation level of the rubber sample under pressure, realizes online and real-time monitoring of the stress relaxation level of the sample under a test environment, ensures the stability and continuity of the monitoring data, and improves the authenticity and accuracy of the monitoring results.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber product testing, and in particular relates to a rubber stress relaxation in-situ test monitoring device, a test method and a monitoring method. Background Art

[0002] The existing industry standard GB / T 7759.2-2014 only provides a conventional rubber stress relaxation test device, which can only be operated outside the test chamber when in use. It is impossible to realize the in-situ test monitoring of rubber stress relaxation (that is, monitoring during the test or in the test chamber, in-situ refers to the position of the rubber material during the test), and cannot meet the in-situ testing and online monitoring needs of rubber materials.

[0003] More importantly, many rubber materials used in low temperature (not higher than -70℃) or high temperature (not lower than 100℃) environments need to be accelerated under harsher conditions. There is currently no accurate and efficient method for collecting rubber test data in this situation, because the main operation method is: first open the test box, then take out the rubber material loading device, then measure the corresponding data, then put the rubber material loading device back into the test box, and then close the test box to continue the test. Obviously, this series of operation processes not only affects the stability and continuity of the test environment, but especially the discontinuity and changes in environmental factors during the operation process will cause the test results to deviate significantly from the actual value, and the operation process is very cumbersome and extremely inefficient. Summary of the invention

[0004] In view of the technical problems mentioned in the background technology, the purpose of the present invention is to provide a rubber stress relaxation in-situ test monitoring device, test method and monitoring method, which can at least accurately and efficiently carry out in-situ testing and online monitoring of rubber materials under extreme environments.

[0005] The present invention adopts the following technical solution.

[0006] A rubber stress relaxation in-situ test monitoring device comprises a rubber sample mounting portion, which is arranged at the periphery of the central area on the top of a heat-insulating shell, the rubber sample mounting portion is connected to a rubber compression control mechanism located in the heat-insulating shell, and a visual terminal is arranged in the central area on the top of the heat-insulating shell, the visual terminal is arranged in a quartz glass cover, and the visual terminal is used to photograph the rubber sample.

[0007] Furthermore, an insulation tube is arranged in the inner cavity of the quartz glass cover, the insulation tube sleeve is arranged on the visual terminal mounting tube, a through hole is radially arranged on the insulation tube, the lens of the visual terminal is located at the through hole and can shoot the rubber sample from the through hole.

[0008] Furthermore, the rubber compression control mechanism adopts a telescopic mechanism, a force sensor is arranged on the telescopic rod of the telescopic mechanism, a pressure plate is fixedly arranged on the top of the telescopic rod, a fixed plate is arranged directly above the pressure plate, and the hollow space between the pressure plate and the fixed plate is used to place the rubber sample; when the telescopic rod of the telescopic mechanism is retracted, the height of the hollow space becomes larger; when the telescopic rod of the telescopic mechanism is extended, the height of the hollow space becomes smaller.

[0009] As a preferred solution, the heat-insulating shell is cylindrical, and five groups of rubber sample mounting parts are arranged on the top of the heat-insulating shell, and each group of rubber sample mounting parts is equipped with a telescopic mechanism arranged at intervals.

[0010] Furthermore, the telescopic rod of each telescopic mechanism is connected to the pressing plate through a linear bearing, and a heat insulation layer is provided at the lower end of the pressing plate.

[0011] Furthermore, the heat-insulating shell includes a coaxially arranged outer shell, an insulation layer and an inner shell, the insulation layer is sandwiched between the outer shell and the inner shell; a cooling element is arranged in the inner cavity of the inner shell; and the electrical control part of the rubber compression control mechanism is located in the inner cavity of the inner shell.

[0012] Furthermore, the fixing plate is a prism plate, holes are opened at the two corners of the prism plate and fastening bolts are arranged, and the hollow area is just below the center of the prism plate, which faces the lens of the visual terminal. Such a solution can obtain the posture of the rubber sample more accurately, more standardly and more clearly, and is particularly suitable for testing and monitoring circular or rectangular rubber sealing rings.

[0013] A constant displacement test method using the aforementioned rubber stress relaxation in-situ test monitoring device, comprising the following steps: Step 1, controlling the rubber compression control mechanism to be in an initial state; Step 2, placing the rubber sample in the hollow space between the pressing plate and the fixing plate; Step 3, controlling the rubber compression control mechanism to operate so that the telescopic rod moves up to the first target position and then pauses, and at this time the fixed plate just sticks to the top surface of the rubber sample; Step 4, placing the rubber stress relaxation in-situ test monitoring device in a test box; Step 5, control the cooling element to work, control the visual terminal to start, and control the test chamber to run; Step 6, first control the visual terminal to photograph the rubber sample in a non-compressed state, then control the rubber compression control mechanism to operate so that the telescopic rod moves upward, and in the process photograph the rubber sample in a compressed state in real time; Step 7, when the rubber sample in the compressed state is photographed to be compressed to the target thickness, the rubber compression control mechanism is controlled to maintain this state, and then an accelerated test is performed on the rubber sample according to preset experimental parameters.

[0014] Step 8, generating a residual stress-time graph / data of the rubber sample under constant displacement (compression value) conditions according to the obtained compression posture, force value information, and test time information.

[0015] A constant stress monitoring method using the above-mentioned rubber stress relaxation in-situ test monitoring device comprises the following steps: Step 11, controlling the rubber compression control mechanism to be in an initial state; Step 12, placing the rubber sample in the hollow space between the pressing plate and the fixing plate; Step 13, controlling the rubber compression control mechanism to operate so that the telescopic rod moves up to the first target position and then pauses, at which time the fixed plate just sticks to the top surface of the rubber sample, and the force value fed back by the force sensor is close to zero; Step 14, placing the rubber stress relaxation in-situ test monitoring device in a test box; Step 15, controlling the cooling element to work, controlling the visual terminal to start, and controlling the test chamber to run; Step 16, first control the visual terminal to photograph the rubber sample in a non-compressed state, then control the rubber compression control mechanism to operate so that the telescopic rod moves upward, and in this process, detect the reading of the pressure sensor in real time; Step 17, when the pressure sensor reading reaches the set pressure value, the rubber compression control mechanism is controlled to maintain this state, and then an accelerated test is performed on the rubber sample according to preset experimental parameters.

[0016] Step 18, the pressure sensor detects the stress state of the rubber sample at a set constant frequency. If the stress decreases, the rubber compression control mechanism is controlled to operate so that the telescopic rod moves upward, thereby maintaining the set pressure value.

[0017] Step 19, during this process, the rubber sample in the compressed state is photographed at a set frequency; and whenever the visual terminal feeds back a compression posture of the rubber sample, the compression amount of the rubber sample is calculated, and the force sensor feeds back corresponding force value information; Step 20, generating a compression thickness-time graph / data of the rubber sample under constant stress conditions according to the obtained compression posture, force value information, and test time information.

[0018] In the present invention, the obtained pixels of the rubber sample are calibrated, each pixel after calibration corresponds to a unit actual height, and then the compression amount of the rubber sample is calculated according to the number of pixels.

[0019] Beneficial effects: By adopting the scheme of the present invention, in-situ monitoring of the stress relaxation level of the rubber sample under pressure is realized, and online and real-time monitoring of the stress relaxation level of the sample is realized under the test environment, which ensures the stability and continuity of the monitoring data and improves the authenticity and accuracy of the monitoring results; by adopting the scheme of the present invention, the operation process is simple and efficient, and it is particularly suitable for in-situ monitoring and detection under low or high temperature environments; during the test, there is no need to take out the sample to determine the relevant test data, and long-term in-situ test monitoring of the rubber sample under constant displacement or constant stress conditions can be realized; by adopting the scheme of the present invention, the rubber sample can be accurately controlled to be compressed to any target thickness for monitoring, and the corresponding target thickness error is not greater than 0.01mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the external structure of the rubber stress relaxation in-situ test monitoring device in Example 1; Figure 2 Schematic cross-sectional view of the in-situ test monitoring device for rubber stress relaxation in Example 1; Figure 3 This is a top view schematic diagram of the in-situ test monitoring device for rubber stress relaxation in Example 1; Figure 4 for Figure 2 A partial enlarged view of the . DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0022] Combination Figures 1 to 4 As shown, a rubber stress relaxation in-situ test monitoring device includes a rubber sample mounting part 2. The figure schematically shows five rubber sample mounting parts 2, which can simultaneously test five samples. The rubber sample mounting part 2 is arranged on the periphery of the central area of ​​the top of the insulation shell 1. The rubber sample mounting part 2 is connected to the rubber compression control mechanism located in the insulation shell 1. A visual terminal is arranged in the central area of ​​the top of the insulation shell 1. The visual terminal is arranged in a quartz glass cover 4. The visual terminal is used to photograph the rubber sample 16.

[0023] In this embodiment, a heat-insulating cylinder 5 is provided in the inner cavity of the quartz glass cover 4, and the heat-insulating cylinder 5 is sleeved on the visual terminal mounting cylinder 7. The heat-insulating cylinder 5 and the quartz glass cover 4 are coaxially arranged, and a through hole 6 is radially provided on the heat-insulating cylinder 5. The lens of the visual terminal is located at the through hole 6 and can shoot the side wall of the rubber sample 16 from the through hole 6. A light hole is provided on the visual terminal mounting cylinder 7 and near the through hole 6, and a fill light is installed at the light hole so that the visual terminal can shoot under standard lighting conditions.

[0024] In this embodiment, the rubber compression control mechanism adopts a telescopic mechanism, which can specifically adopt an electric push rod or a screw lifting mechanism that can control the stroke. When the screw lifting mechanism is adopted, the lifting rod can be regarded as a telescopic rod. A force sensor 18 is arranged on the telescopic rod of the telescopic mechanism. A pressure plate 8 is fixedly arranged on the top of the telescopic rod. A fixed plate 10 is arranged directly above the pressure plate 8. The fixed plate 10 is fixedly connected to the top surface of the shell 11 through a connecting rod. The hollow space between the pressure plate 8 and the fixed plate 10 is used to place the rubber sample 16; when the telescopic rod of the telescopic mechanism is retracted, the height of the hollow space becomes larger; when the telescopic rod of the telescopic mechanism is extended, the height of the hollow space becomes smaller.

[0025] In this embodiment, the heat-insulating housing 1 is cylindrical, and four or five groups of rubber sample mounting parts 2 are arranged on the top of the heat-insulating housing 1. Each group of rubber sample mounting parts 2 is provided with two telescopic mechanisms arranged at intervals. The telescopic rod of each telescopic mechanism (or the lifting rod of the screw lifting mechanism) is connected to the pressing plate 8 through a linear bearing 17. The lower end of the pressing plate 8 is provided with a heat-insulating layer 15, and the heat-insulating layer 15 is integrally formed with the heat-insulating cylinder 5.

[0026] In this embodiment, the heat-insulating shell 1 includes a coaxially arranged outer shell 11, an insulation layer 12 and an inner shell 13, wherein the insulation layer 12 is sandwiched between the outer shell 11 and the inner shell 13; a cooling element 9 is arranged in the inner cavity of the inner shell 13; and the electronic control part of the rubber compression control mechanism is located in the inner cavity of the inner shell 13. The fixing plate 10 is a prismatic plate, and holes are opened at the two corners of the prismatic plate and fastening bolts are arranged. The hollow area is just below the center of the prismatic plate, and the area faces the lens of the visual terminal. Such a solution can obtain the posture of the rubber sample more accurately, more standardly and more clearly, and is particularly suitable for testing and monitoring circular or rectangular rubber sealing rings.

[0027] The cooling element 9 in this embodiment adopts a spiral tube, and the spiral tube is externally connected to a circulating coolant supply system, which is used to control the coolant to flow continuously in the spiral tube, thereby taking away the heat of the inner cavity of the inner shell 13. Similarly, when the coolant adopts a hot fluid with a higher temperature, it can continuously supply heat to the inner cavity of the inner shell 13, so that the inner cavity of the inner shell 13 is maintained in a suitable temperature range. In addition, a fan is also provided in the inner cavity of the inner shell 13 to enhance the heat exchange efficiency between the inner cavity of the inner shell 13 and the cooling element 9.

[0028] In this embodiment, the insulation layer 12 and the insulation tube 5 are both made of aerogel material; the rubber compression control mechanism, the visual terminal, the force sensor 18, and the circulating coolant supply system are all connected to the control system, and their operation is controlled by the control system.

[0029] Before using the in-situ test monitoring device for rubber stress relaxation in this embodiment, the device is debugged and calibrated first, and the obtained rubber sample 16 pixels are calibrated. Each pixel after calibration corresponds to a unit of actual height, and then the compression of the rubber sample 16 is calculated according to the number of pixels. For example: the actual height corresponding to a calibrated pixel of a certain type of rubber sample 16 is 0.003mm. When the number of single-row pixels in the height direction of the side wall of the rubber sample 16 in the image taken in the non-compressed state is 3000, the corresponding height of the side wall of the rubber sample 16 (i.e., the initial thickness of the rubber sample 16) is 9mm; when the number of single-row pixels in the height direction of the side wall of the rubber sample 16 in the image taken in the compressed state is 2500, the corresponding height of the side wall of the rubber sample 16 (i.e., the thickness of the rubber sample 16 after compression) is 7.5mm; therefore, the compression of the rubber sample 16 can be calculated to be 1.5mm. Example 2

[0030] A constant displacement test method using the rubber stress relaxation in-situ test monitoring device in Example 1, comprising the following steps: Step 1, controlling the rubber compression control mechanism to be in an initial state; Step 2: Place the rubber sample 16 in the hollow space between the pressing plate 8 and the fixing plate 10. Figure 2 There is a hint in it; Step 3, control the rubber compression control mechanism to operate, so that the telescopic rod moves up to the first target position and then pauses. At this time, the fixed plate 10 is just against the top surface of the rubber sample 16. The state at this time is as follows: Figure 4 As shown; Step 4, placing the rubber stress relaxation in-situ test monitoring device in a test box; Step 5, controlling the cooling element 9 to work, controlling the visual terminal to start, and controlling the test chamber to run; Step 6, first control the visual terminal to photograph the rubber sample 16 in a non-compressed state, then control the rubber compression control mechanism to operate so that the telescopic rod moves upward, and in the process photograph the rubber sample 16 in a compressed state in real time; Step 7, when the rubber sample 16 in the compressed state is photographed to be compressed to the target thickness, the rubber compression control mechanism is controlled to maintain this state, and then an accelerated test is performed on the rubber sample 16 according to preset experimental parameters.

[0031] Step 8, generating a residual stress-time graph / data of the rubber sample under constant displacement (compression value) conditions according to the obtained compression posture, force value information, and test time information. Example 3

[0032] A constant stress monitoring method using the rubber stress relaxation in-situ test monitoring device in Example 1, comprising the following steps: Step 11, controlling the rubber compression control mechanism to be in an initial state; Step 12, placing a rubber sample 16 in the hollow space between the pressing plate 8 and the fixing plate 10; Step 13, control the rubber compression control mechanism to operate so that the telescopic rod moves up to the first target position and then pauses. At this time, the fixed plate 10 is just against the top surface of the rubber sample 16. Figure 4 As shown, the force value fed back by the force sensor 18 is close to zero; Step 14, placing the rubber stress relaxation in-situ test monitoring device in a test box; Step 15, controlling the cooling element 9 to work, controlling the visual terminal to start, and controlling the test box to run; Step 16, first control the visual terminal to photograph the rubber sample 16 in a non-compressed state, then control the rubber compression control mechanism to operate so that the telescopic rod moves upward, and in this process, detect the reading of the pressure sensor 18 in real time; Step 17, when the reading of the pressure sensor 18 reaches the set pressure value, the rubber compression control mechanism is controlled to maintain this state, and then an accelerated test is performed on the rubber sample 16 according to the preset experimental parameters.

[0033] Step 18, the pressure sensor 18 detects the stress state of the rubber sample 16 at a set constant frequency. If the stress is reduced, the rubber compression control mechanism is controlled to operate so that the telescopic rod moves upward, thereby maintaining the set pressure value.

[0034] Step 19, photographing the rubber sample 16 in a compressed state at a set frequency; and whenever the visual terminal feeds back a compression posture of the rubber sample, calculating the compression amount of the rubber sample, and the force sensor feeds back corresponding force value information; Step 20, generating a compression thickness-time graph / data of the rubber sample under constant stress conditions according to the obtained compression posture, force value information, and test time information.

[0035] In this embodiment: when the fixing plate 10 is just against the top surface of the rubber sample 16, the force value fed back by the force sensor 18 is close to zero, and the corresponding compression thickness of the rubber sample 16 is 0; in the subsequent constant stress continuous loading process, the force value fed back by the force sensor 18 is compensated to a constant value, and the corresponding compression thickness of the rubber sample 16 will gradually increase. A series of thickness values ​​will be obtained as time changes, and the rubber sample compression thickness-time chart / data can be obtained based on these data.

[0036] By adopting the scheme of the embodiment, in-situ monitoring of the stress relaxation level of the rubber sample under pressure is realized, and online and real-time monitoring of the stress relaxation level of the sample is realized under the test environment, thereby ensuring the stability and continuity of the monitoring data and improving the authenticity and accuracy of the monitoring results; the operation process is simple and efficient, and is particularly suitable for in-situ monitoring and detection in low or high temperature environments; during the test, there is no need to take out the sample to determine the relevant test data, and long-term in-situ test monitoring of the rubber sample under constant displacement or constant stress conditions can be realized; the rubber sample can be accurately controlled to be compressed to any target thickness for monitoring, and the corresponding target thickness error is no more than 0.01mm.

Claims

1. A rubber stress relaxation in-situ test monitoring device, comprising a rubber sample mounting portion, characterized in that: The rubber sample mounting part is arranged on the periphery of the central area on the top of the thermal insulation shell, and the rubber sample mounting part is connected to the rubber compression control mechanism located in the thermal insulation shell. A visual terminal is arranged in the central area on the top of the thermal insulation shell, and the visual terminal is arranged in a quartz glass cover. The visual terminal is used to photograph the rubber sample.

2. The rubber stress relaxation in-situ test monitoring device according to claim 1, characterized in that: An insulation cylinder is arranged in the inner cavity of the quartz glass cover, and the insulation cylinder sleeve is arranged on the visual terminal mounting cylinder. A through hole is radially arranged on the insulation cylinder. The lens of the visual terminal is located at the through hole and can shoot the rubber sample from the through hole.

3. The rubber stress relaxation in-situ test monitoring device according to claim 2, characterized in that: The rubber compression control mechanism adopts a telescopic mechanism, a force sensor is arranged on the telescopic rod of the telescopic mechanism, a pressure plate is fixedly arranged on the top of the telescopic rod, a fixed plate is arranged directly above the pressure plate, and the hollow space between the pressure plate and the fixed plate is used to place the rubber sample; when the telescopic rod of the telescopic mechanism is retracted, the height of the hollow space becomes larger; when the telescopic rod of the telescopic mechanism is extended, the height of the hollow space becomes smaller.

4. The rubber stress relaxation in-situ test monitoring device according to claim 3, characterized in that: The heat-insulating shell is cylindrical, and five groups of rubber sample mounting parts are arranged on the top of the heat-insulating shell. Each group of rubber sample mounting parts is equipped with a telescopic mechanism arranged at intervals.

5. The rubber stress relaxation in-situ test monitoring device according to claim 4, characterized in that: The telescopic rod of each telescopic mechanism is connected to the pressing plate through a linear bearing, and a heat insulation layer is arranged at the lower end of the pressing plate.

6. The rubber stress relaxation in-situ test monitoring device according to claim 5, characterized in that: The heat-insulating shell comprises a coaxially arranged outer shell, a heat-insulating layer and an inner shell, wherein the heat-insulating layer is sandwiched between the outer shell and the inner shell; a cooling element is arranged in the inner cavity of the inner shell; and the electric control part of the rubber compression control mechanism is located in the inner cavity of the inner shell.

7. The rubber stress relaxation in-situ test monitoring device according to any one of claims 1 to 6, characterized in that: The fixing plate is a prismatic plate, with holes opened at the two corners of the prismatic plate and fastening bolts arranged thereon, and a hollow area directly below the center of the prismatic plate, which faces the lens of the visual terminal. This solution can obtain the posture of the rubber sample more accurately, more standardly, and more clearly, and is particularly suitable for testing and monitoring circular or rectangular rubber sealing rings.

8. A constant displacement test method using the rubber stress relaxation in-situ test monitoring device as claimed in claim 7, characterized in that the steps include: Step 1, controlling the rubber compression control mechanism to be in an initial state; Step 2, placing the rubber sample in the hollow space between the pressing plate and the fixing plate; Step 3, controlling the rubber compression control mechanism to operate so that the telescopic rod moves up to the first target position and then pauses, and at this time the fixed plate just sticks to the top surface of the rubber sample; Step 4, placing the rubber stress relaxation in-situ test monitoring device in a test box; Step 5, control the cooling element to work, control the visual terminal to start, and control the test chamber to run; Step 6, first control the visual terminal to photograph the rubber sample in a non-compressed state, then control the rubber compression control mechanism to operate so that the telescopic rod moves upward, and in the process photograph the rubber sample in a compressed state in real time; Step 7, when the rubber sample in the compressed state is photographed to be compressed to the target thickness, the rubber compression control mechanism is controlled to maintain the state, and then an accelerated test is performed on the rubber sample according to preset experimental parameters; Step 8, generating a residual stress-time graph / data of the rubber sample under constant displacement (compression value) conditions according to the obtained compression posture, force value information, and test time information.

9. A constant stress monitoring method using the rubber stress relaxation in-situ test monitoring device as claimed in claim 7, characterized in that the steps include: Step 11, controlling the rubber compression control mechanism to be in an initial state; Step 12, placing the rubber sample in the hollow space between the pressing plate and the fixing plate; Step 13, controlling the rubber compression control mechanism to operate so that the telescopic rod moves up to the first target position and then pauses, at which time the fixed plate just sticks to the top surface of the rubber sample, and the force value fed back by the force sensor is close to zero; Step 14, placing the rubber stress relaxation in-situ test monitoring device in a test box; Step 15, controlling the cooling element to work, controlling the visual terminal to start, and controlling the test chamber to run; Step 16, first control the visual terminal to photograph the rubber sample in a non-compressed state, then control the rubber compression control mechanism to operate so that the telescopic rod moves upward, and in this process, detect the reading of the pressure sensor in real time; Step 17, when the pressure sensor reading reaches the set pressure value, the rubber compression control mechanism is controlled to maintain this state, and then an accelerated test is performed on the rubber sample according to preset experimental parameters; Step 18, the pressure sensor detects the stress state of the rubber sample at a set constant frequency. If the stress is reduced, the rubber compression control mechanism is controlled to operate so that the telescopic rod moves upward, thereby maintaining the set pressure value; Step 19, during this process, the rubber sample in the compressed state is photographed at a set frequency; and whenever the visual terminal feeds back a compression posture of the rubber sample, the compression amount of the rubber sample is calculated, and the force sensor feeds back corresponding force value information; Step 20, generating a compression thickness-time graph / data of the rubber sample under constant stress conditions according to the obtained compression posture, force value information, and test time information.

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