Universal full-automatic creep deformation and stress relaxation testing device and testing method

Abstract

The invention relates to a universal full-automatic creep deformation and stress relaxation testing device and a testing method. The device comprises a base, a first support assembly, an automatic sliding table module and a hand-cranking sliding table module. The automatic sliding table module comprises a lead screw guide rail sliding block assembly and a pressure sensor fixing piece, a pressure sensor is fixedly arranged on the lower portion of the pressure sensor fixing piece, a large gear is fixedly arranged at the upper end of a lead screw and meshed with a small gear (10), and an output shaft of a stepping motor is fixedly arranged at the axis of the small gear. The hand-cranking sliding table module comprises a lead screw guide rail sliding block assembly, a displacement sensor fixing piece and a displacement sensor. A hand-cranking pulley is fixedly arranged at the upper end of a lead screw. The test method comprises a creep test and a stress relaxation test. The device has the advantages that the working stability of the measuring device is greatly improved, and the safety of a to-be-tested piece and the device is ensured; functions are rich, and applicability is high; the device can work for a long time in a high-temperature and high-humidity environment.

Description

Technical Field

[0001] The invention relates to the technical field of creep property and stress relaxation property determination, in particular to a universal full-automatic creep and stress relaxation test device and a test method. Background Art

[0002] Temperature and deformation are two important factors that affect the creep and stress relaxation of polymer materials. Under continuous high temperature and constant external force, the thermal motion of polymer molecules will be accelerated, which will speed up the creep process. The macroscopic manifestation is that the creep rate is accelerated, and the stress inside the polymer gradually decays with time.

[0003] At present, in the field of creep and stress relaxation characteristic determination technology, relevant equipment has been developed to measure creep and stress relaxation characteristics. A detection device for creep-resistant plastic profiles disclosed in the patent with application number 202121491282.1 includes a fixing mechanism, a pillar, a cover plate, a gas rod, a detection plate, an adjustment mechanism and a base. The detection device has the following problems: 1. The upper side of the support plate in the adjustment mechanism is bolted with a motor, and the support plate cannot fully fix the motor, so the motor will vibrate when working, resulting in unstable operation of the device; 2. A support rod is welded on the outside of the threaded sleeve, and a pad is bolted on the upper side of the support rod. The support rod is a structure with two 45° inclined and symmetrical with the threaded sleeve as the symmetry axis. There is no supporting structure below it except the threaded sleeve, and it cannot play a good load-bearing role. 3. It can only measure the creep characteristics of the material, but cannot measure the stress relaxation characteristics of the material, and has a single function. 4. Frequent manual operation is required, which is inconvenient to operate. 5. It is not resistant to high temperature and humidity, and cannot work for a long time in a high temperature and humidity environment. Summary of the invention

[0004] The present invention provides a universal fully automatic creep and stress relaxation testing device and testing method to solve the problems of unstable operation, poor load-bearing, single function, inconvenient operation and inability to withstand high temperature and humidity in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A universal fully automatic creep and stress relaxation testing device comprises a base, wherein a first bracket assembly is arranged at one end of the base 1, an automatic slide module is arranged in the middle, and a hand-cranked slide module is arranged at the other end;

[0007] The automatic slide module comprises a lead screw guide rail slider assembly and a pressure sensor fixing part, the lead screw guide rail slider assembly comprises a lead screw and a slider that can be moved up and down to position, the slider is fixedly connected to the pressure sensor fixing part, and the lower part of the pressure sensor fixing part is fixedly provided with a pressure sensor; the lower end of the lead screw is rotatably provided on the base, the upper end of the lead screw is fixedly provided with a large gear, the large gear is meshed with a small gear, the output shaft of the stepping motor is fixedly provided at the axis center of the small gear, the stepping motor is provided on the fixing plate, and the fixing plate is provided on the first bracket assembly;

[0008] The hand-cranked slide module comprises a lead screw guide rail slider assembly, a displacement sensor fixing part and a displacement sensor, wherein the lead screw guide rail slider assembly comprises a lead screw and a slider that can be moved up and down for positioning, the slider is fixedly connected to the displacement sensor fixing part, and the displacement sensor is fixedly arranged at the lower part of the displacement sensor fixing part; the lower end of the lead screw is rotatably arranged on the base, and the upper end of the lead screw is fixedly arranged with a hand-cranked pulley;

[0009] The displacement sensor is arranged adjacent to the pressure sensor fixing piece, and the movement track of the displacement sensor is located at the upper front end of the pressure sensor fixing piece;

[0010] The two screw guide rail slider assemblies are fixed on the second bracket assembly, and the second bracket assembly includes a crossbeam and columns arranged at the lower parts of both ends of the crossbeam. The screw of the screw guide rail slider assembly can be movably passed through the crossbeam, and the columns are fixedly arranged on the base.

[0011] Furthermore, the above-mentioned first bracket assembly includes a first horizontal support rod, a first vertical rod, a second vertical rod and a second horizontal support rod. The first horizontal bracket is arranged at the upper part of the base, and the first vertical rod and the second vertical rod are arranged at the upper part of its two ends. The second horizontal support rod is spanned in the middle of the first vertical rod and the second vertical rod.

[0012] Furthermore, a triangular support member is provided on the column on one side of the automatic slide module, and a second horizontal support rod is supported on the upper plane of the triangular support member.

[0013] Furthermore, the pressure sensor fixing piece is a plate-shaped right triangle; the displacement sensor fixing piece is a cylinder.

[0014] Furthermore, the lower ends of the lead screws in the above-mentioned two lead screw guide rail slider assemblies are rotatably arranged on the slide module base fixedly arranged on the base 1.

[0015] Furthermore, the fixing plate is fixed to the upper part of the second horizontal support rod by bolts; and the stepping motor and the motor fixing plate are fixed by screws.

[0016] Furthermore, the first vertical rod and the second vertical rod in the above-mentioned first bracket assembly are fixed to the first horizontal support rod and the second horizontal support rod respectively by angle irons.

[0017] Furthermore, the base 1 , the first bracket assembly and the second bracket assembly are made of 6061 aluminum alloy, and the slider 21 is made of 304 stainless steel.

[0018] Furthermore, the present invention provides a testing method for a universal fully automatic creep and stress relaxation testing device. During the creep test: first, the stepper motor is controlled to drive the pressure sensor to press down to the titanium alloy gasket above the test piece; then the control board controls the stepper motor to drive the pressure sensor to slightly lift up, and the creep measurement process starts: the stepper motor is controlled to drive the pressure sensor to continuously apply a constant pressure to the test piece, and the pressure value collected by the pressure sensor, the displacement collected by the displacement sensor, and the displacement rebound amount obtained by subtracting the current displacement from the initial displacement are sent to the control component to end the measurement.

[0019] Furthermore, the present invention provides a testing method for a universal fully automatic creep and stress relaxation testing device. In the stress relaxation test: first, the stepper motor is controlled to drive the pressure sensor to press down to the titanium alloy gasket above the test piece, and the stepper motor is controlled to drive the pressure sensor to slightly lift up to start the stress relaxation measurement process: the stepper motor drives the pressure sensor to press down so that the displacement collected by the displacement sensor reaches a predetermined height, maintains the predetermined height, and sends the pressure value collected by the pressure sensor, the displacement collected by the displacement sensor, and the displacement rebound amount obtained by subtracting the current displacement from the initial displacement to the control component to end the measurement.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. A first horizontal bracket is arranged at the left end of the base, and two vertical brackets are arranged above the first horizontal bracket. The two vertical brackets are respectively placed at the two ends of the first horizontal bracket, and two angle irons are used to fix the two vertical brackets to the first horizontal bracket. A second horizontal bracket is arranged on the right side of the two vertical brackets, and the two vertical brackets are vertically close to the first horizontal bracket and the second horizontal bracket, and two angle irons are used to fix the two vertical brackets to the second horizontal bracket. A stepper motor and a motor fixing plate are arranged above the second horizontal bracket to fix the stepper motor to the motor fixing plate. Through the above structural design, the stability and load-bearing capacity of the measuring equipment are improved. During the working process, the motor will not shake, which greatly improves the working stability of the measuring device.

[0022] 2. In the structure of the automatic slide module, in order to control the rotation of the stepper motor, thereby driving the slider on it to move up and down, and the moving position is controllable, automatic control can be used to avoid interference and errors caused by improper manual operation to the greatest extent, making the measurement process more stable and the measurement results more accurate. In the manual slide module, turn the manual pulley to control the up and down movement of the displacement sensor. In addition, when the automatic slide module works abnormally, the manual slide module can also calibrate the pressure abnormality to ensure the safety of the test piece and the device.

[0023] 3. The measuring method of the present invention is simple and easy to operate: it can measure both the creep characteristics of polymer materials and the stress relaxation characteristics of polymer materials, integrating creep characteristic measurement and stress relaxation characteristic measurement in one, with rich functions and strong applicability.

[0024] 4. Due to the use of automatic slide module, there is no need for frequent manual operation, and the operation is convenient. At the same time, because the base and frame support structure are made of 6061 aluminum alloy, the active parts are made of 304 stainless steel, and the high-stress structure is made of TC4 titanium alloy, the active parts are sliders, and the high-stress structure is a titanium alloy gasket, it can work for a long time in high temperature and high humidity environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the measuring device of the present invention.

[0026] Figure 2 A flowchart of the workflow.

[0027] Figure 3 It is a partial top view.

[0028] The following are the descriptions of the reference numerals:

[0029] 1. Base; 2. First horizontal support rod; 3. Test piece; 4. Titanium alloy gasket; 5. First vertical rod; 6. Second vertical rod; 7. Second horizontal support rod; 8. Fixed plate; 9. Stepper motor; 10. Small gear; 11. Large gear; 12. Pressure sensor fixing part; 13. Pressure sensor; 14. Displacement sensor fixing part; 15. Displacement sensor; 16. Hand pulley; 17. Crossbeam; 18. Slide module base; 19. Lead screw; 20. Column; 21. Slider; 22. Angle iron; 23. Triangular support. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is clearly and completely described below in conjunction with the specific implementation modes of the present invention and the accompanying drawings.

[0031] See also Figure 1 and Figure 2A universal fully automatic creep and stress relaxation testing device comprises a base 1, one end of the base 1 is provided with a first bracket assembly, the middle is provided with an automatic slide module, and the other end is provided with a hand-cranked slide module.

[0032] The first bracket assembly includes a first horizontal support rod 2, a first vertical rod 5, a second vertical rod 6 and a second horizontal support rod 7. The first horizontal support rod is arranged on the upper part of the base 1, and the first vertical rod 5 and the second vertical rod 6 are arranged on the upper part of the two ends of the first horizontal support rod. The middle part of the first vertical rod 5 and the second vertical rod 6 is spanned by the second horizontal support rod 7.

[0033] The automatic slide module includes a screw guide rail slider assembly and a pressure sensor fixing part 12. The screw guide rail slider assembly includes a screw 19 and a slider 21 that can be moved up and down to position. The slider 21 is fixedly connected to the pressure sensor fixing part 12, and the lower part of the pressure sensor fixing part 12 is fixedly provided with a pressure sensor 13; the lower end of the screw 19 in the screw guide rail slider assembly is rotatably provided on the slide module base 18 fixedly provided on the base 1. A large gear 11 is fixedly provided on the upper end of the screw 19, and the large gear 11 is meshed with a small gear 10. The output shaft of the stepper motor 9 is fixed at the axis of the small gear 10. The stepper motor 9 is fixed to the fixing plate 8 by screws, and the fixing plate 8 is fixed to the upper part of the second horizontal support rod 7 by nickel-plated 30-M8 bolts.

[0034] The hand-cranked slide module includes a lead screw guide rail slider assembly, a displacement sensor fixing platform 14 and a displacement sensor 15. The lead screw guide rail slider assembly includes a lead screw 19 and a slider 21 that can be moved up and down. The slider 21 is fixedly connected to the displacement sensor fixing part 14, and the displacement sensor 15 is fixedly arranged at the lower part of the displacement sensor fixing part 14. The lower end of the lead screw 19 in the two lead screw guide rail slider assemblies is rotatably arranged on the slide module base 18 fixedly arranged on the base 1. The upper end of the lead screw 19 is fixedly arranged with a hand-cranked pulley 16.

[0035] The displacement sensor 15 is arranged adjacent to the pressure sensor fixing part 12, and the pressure sensor fixing part 12 is a plate-shaped right-angled triangle. The pressure sensor fixing part 12 is arranged on the lower horizontal plane of the pressure sensor fixing part 12; the displacement sensor fixing part 14 is cylindrical, and is fixedly connected to the slider 21 of the hand-cranked slide module with an iron plate and screws. The movement trajectory of the displacement sensor 15 is located at the upper front end of the pressure sensor fixing part 12.

[0036] The two screw guide rail slider assemblies are fixed to the second bracket assembly, which includes a cross beam 17 and columns 20 arranged at the lower parts of both ends of the cross beam 17. The screw of the screw guide rail slider assembly 19 is passed through the cross beam 17, and the column 20 is fixedly arranged on the base 1. In this embodiment, the column 20 is "L" shaped, and the horizontal part is arranged at the lower part of the cross beam 17 to improve stability.

[0037] A triangular support member 23 is provided on the column 20 on one side of the automatic slide module, and a second horizontal support rod 7 is supported on the upper horizontal surface of the triangular support member 23 to further improve the stability of the overall structure.

[0038] The first vertical rod 5 and the second vertical rod 6 in the first bracket assembly are fixed to the first horizontal support rod 2 and the second horizontal support rod 7 respectively through angle irons 22.

[0039] The base, the first bracket assembly and the second bracket assembly are made of 6061 aluminum alloy, and the slider 21 is made of 304 stainless steel.

[0040] During operation, the test piece 33 is set below the pressure sensor fixture 12 and the displacement sensor 15, and the titanium alloy gasket 4 is set on the upper part of the test piece. During operation, the displacement sensor 15 moves and is set close to the front upper surface of the pressure sensor fixture 12.

[0041] The stepper motor 9 of the automatic slide module drives the small gear 10 installed on its output shaft to rotate, and the small gear 10 drives the large gear 11 to rotate, so that the large gear 11 drives the lead screw to rotate, and the lead screw drives the slider on it to slide up and down, and at the same time drives the pressure sensor 13 to move up and down.

[0042] The hand-cranked pulley 16 in the hand-cranked slide module rotates, and the lead screw 19 rotates, driving the slider 21 thereon to slide up and down, and at the same time driving the displacement sensor 15 to move up and down.

[0043] The stepper motor 9, displacement sensor 14 and pressure sensor 13 are all connected to a control component, which may include a control box and a host computer. Figure 3 , the test workflow of the device specifically includes the following steps:

[0044] Step 1: Start measuring, prepare the test piece 3, and turn on the control component.

[0045] Step 101, first select a test piece 3 made of polyurethane plastic or fluoroplastic, the test piece is a cuboid or a cylinder, the cuboid has soft and hard textures, and the cylinder has only hard textures. Place the test piece directly below the pressure sensor 13 and the displacement sensor, and place a titanium alloy gasket 4 above them, in order to ensure that the contact surface of the test piece 3 is smooth and flat, and avoid experimental errors caused by uneven force due to uneven contact surface.

[0046] Step 102: Power on the device and remove the force, and adjust the pressure of the pressure sensor 13 to zero:

[0047] (1) If the control component shows that there is a current pressure value, the stepper motor 9 is controlled to drive the pressure sensor 13 to move upward. The control component shows that the current pressure is zero.

[0048] (2) If the pressure of the pressure sensor 13 is not zero, the stepper motor 9 is controlled to drive the pressure sensor 13 to move upward. When the pressure sensor 13 completely leaves the titanium alloy gasket 4 and its pressure value is zero, the stepper motor 9 is controlled again to drive the pressure sensor 13 to move downward. This time, the pressure sensor 13 just touches the titanium alloy gasket 4, and the pressure value displayed by the control component is not zero but very small. At this time, the stepper motor 9 is controlled to drive the pressure sensor 13 to move upward until the displayed pressure value is zero. The purpose of this is to completely ensure that the initial pressure value is zero.

[0049] (3) If the pressure sensor 13 completely leaves the titanium alloy gasket 4, but its pressure value is not zero, that is, when the zero point position of the pressure sensor 13 drifts, the control component sends a reset instruction to the pressure sensor 13 to eliminate the zero point drift of the pressure sensor 13, and then proceeds to the subsequent process.

[0050] Step 2: Toggle the switch to control the creep working mode, stress relaxation working mode and parameter configuration mode.

[0051] In the creep working mode, first control the stepper motor 9 to drive the pressure sensor 13 to press down to the titanium alloy gasket 4 above the test piece 3; then the control board 39 controls the stepper motor 9 to drive the pressure sensor 13 to slightly lift up, and start the creep measurement process: control the stepper motor 9 to drive the pressure sensor 13 to continuously apply a constant pressure to the test piece 3, and send the pressure value collected by the pressure sensor 13 and the displacement collected by the displacement sensor 15, as well as the displacement rebound obtained by subtracting the current displacement from the initial displacement, to the control component to end the measurement. Control the stepper motor 9 to drive the pressure sensor 13 to move upward, completely away from the titanium alloy gasket 4, the pressure value of the pressure sensor 13 is zero, and the device is reset.

[0052] In the stress relaxation working mode, first control the stepper motor 9 to drive the pressure sensor 13 to press down to the titanium alloy gasket 4 above the test piece 3, and control the stepper motor 9 to drive the pressure sensor 13 to lift slightly to start the stress relaxation measurement process: the stepper motor 9 drives the pressure sensor 13 to press down, so that the displacement collected by the displacement sensor 15 reaches a predetermined height, maintains the predetermined height, and sends the pressure value collected by the pressure sensor 13 and the displacement collected by the displacement sensor 15, as well as the displacement rebound obtained by subtracting the current displacement from the initial displacement, to the control component to end the measurement. Control the stepper motor 9 to drive the pressure sensor 13 to move upward until it completely leaves the titanium alloy gasket 4, the pressure value of the pressure sensor 13 is zero, and the device is reset.

[0053] The parameter configuration mode includes the measurement of target pressure value and target displacement.

[0054] Obviously, the described embodiments are only some embodiments of the present invention, not all 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.

Claims

1. A universal fully automatic creep and stress relaxation testing device, comprising a base (1), characterized in that: The base (1) is provided with a first bracket assembly at one end, an automatic slide module is provided in the middle, and a hand-operated slide module is provided at the other end; The automatic slide module comprises a lead screw guide rail slider assembly and a pressure sensor fixing member (12), the lead screw guide rail slider assembly comprises a lead screw (19) and a slider (21) that can be moved up and down to position, the slider (21) is fixedly connected to the pressure sensor fixing member (12), and the lower part of the pressure sensor fixing member (12) is fixedly provided with a pressure sensor (13); the lower end of the lead screw (19) is rotatably arranged on the base (1), the upper end of the lead screw (19) is fixedly provided with a large gear (11), the large gear (11) is meshed with a small gear (10), the output shaft of a stepping motor (9) is fixedly provided at the axis center of the small gear (10), the stepping motor (9) is arranged on a fixing plate (8), and the fixing plate (8) is arranged on the first bracket assembly; The hand-cranked slide module comprises a lead screw guide rail slider assembly, a displacement sensor fixing part (14) and a displacement sensor (15); the lead screw guide rail slider assembly comprises a lead screw (19) and a slider (21) that can be moved up and down and positioned; the slider (21) is fixedly connected to the displacement sensor fixing part (14); the displacement sensor (15) is fixedly arranged at the lower part of the displacement sensor fixing part (14); the lower end of the lead screw is rotatably arranged on the base (1); the upper end of the lead screw is fixedly arranged with a hand-cranked pulley (16); The displacement sensor (15) is arranged adjacent to the pressure sensor fixing member (12), and the movement track of the displacement sensor (15) is located at the upper front end of the pressure sensor fixing member (12); The two screw guide rail slider assemblies (19) are fixed on a second bracket assembly, the second bracket assembly comprises a crossbeam (17) and columns (20) arranged at the lower parts of both ends of the crossbeam (17), the screw (19) of the screw guide rail slider assembly can be movably passed through the crossbeam (17), and the columns (20) are fixedly arranged on the base (1).

2. A universal fully automatic creep and stress relaxation testing device according to claim 1, characterized in that: The first bracket assembly comprises a first horizontal support rod (2), a first vertical rod (5), a second vertical rod (6) and a second horizontal support rod (7); the first horizontal bracket is arranged on the upper part of the base (1); the first vertical rod (5) and the second vertical rod (6) are arranged on the upper parts of both ends of the first horizontal bracket; the second horizontal support rod (7) is straddled between the middle parts of the first vertical rod (5) and the second vertical rod (6).

3. A universal fully automatic creep and stress relaxation testing device according to claim 2, characterized in that: A triangular support member (23) is provided on a column (20) on one side of the automatic slide module, and a second horizontal support rod (7) is supported on the upper plane of the triangular support member (23).

4. A universal fully automatic creep and stress relaxation testing device according to claim 3, characterized in that: The pressure sensor fixing piece (12) is in the shape of a plate-shaped right-angled triangle; the displacement sensor fixing piece (14) is in the shape of a cylinder.

5. A universal fully automatic creep and stress relaxation testing device according to any of claims 1 to 4, characterized in that: The lower ends of the lead screws (19) in the two lead screw guide rail slider assemblies are rotatably arranged on a slide module base (18) fixedly arranged on the base (1).

6. A universal fully automatic creep and stress relaxation testing device according to claim 5, characterized in that: The fixing plate (8) is fixed to the upper part of the second horizontal support rod (7) by means of bolts; and the stepping motor (9) and the fixing plate (8) are fixed by means of screws.

7. A universal fully automatic creep and stress relaxation testing device according to claim 6, characterized in that: The first vertical rod (5) and the second vertical rod (6) in the first bracket assembly are fixed to the first horizontal support rod (2) and the second horizontal support rod (7) respectively by means of angle irons (22).

8. A universal fully automatic creep and stress relaxation testing device according to claim 7, characterized in that: The base 1, the first bracket assembly and the second bracket assembly are made of 6061 aluminum alloy, and the slider (21) is made of 304 stainless steel.

9. The testing method of a universal fully automatic creep and stress relaxation testing device according to claim 1, characterized in that: In the creep test, the stepper motor (9) is first controlled to drive the pressure sensor (13) to press down on the titanium alloy gasket (4) above the test piece (3); then the control board 39 controls the stepper motor (9) to drive the pressure sensor (13) to slightly lift up, and the creep measurement process begins: the stepper motor (9) is controlled to drive the pressure sensor (13) to continuously apply a constant pressure to the test piece (3), and the pressure value collected by the pressure sensor (13) and the displacement collected by the displacement sensor (15) and the displacement rebound amount obtained by subtracting the current displacement from the initial displacement and other data are sent to the control component to end the measurement.

10. The testing method of a universal fully automatic creep and stress relaxation testing device according to claim 1, characterized in that: In the stress relaxation test, the stepper motor (9) is first controlled to drive the pressure sensor (13) to press down to the titanium alloy gasket (4) above the test piece (3), and the stepper motor (9) is controlled to drive the pressure sensor (13) to slightly lift up, and the stress relaxation measurement process begins: the stepper motor (9) drives the pressure sensor (13) to press down, so that the displacement collected by the displacement sensor (15) reaches a predetermined height, and the predetermined height is maintained, and the pressure value collected by the pressure sensor (13) and the displacement collected by the displacement sensor (15) and the displacement rebound amount obtained by subtracting the current displacement from the initial displacement and other data are sent to the control component to end the measurement.

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