Portable rubber material creep testing device

Abstract

The invention relates to a portable rubber material creep testing device, and belongs to the technical field of creep testing. Comprising a square frame, a fixed clamp, a movable clamp, a pull rod, a linear bearing, a limiting frame, a creep quantity detection assembly and a tensile stress adjusting assembly. The fixing clamp is arranged on the lower surface of the upper frame of the square frame; the movable clamp is arranged below the fixed clamp; the linear bearing is arranged on the upper surface of the lower frame of the square frame; the pull rod is vertically installed at the bottom of the movable clamp, and the bottom of the pull rod penetrates through the lower frame of the square frame downwards. The creep quantity detection assembly and the limiting frame are both installed below the square frame and located on the two opposite sides of the pull rod respectively. The tensile stress adjusting assembly is mounted at the bottom of the pull rod; the top of the to-be-tested sample is fixed on the fixing clamp; the bottom of the to-be-tested sample is fixed on the movable clamp; the friction force between the pull rod and the bottom of the square frame is greatly reduced, so that the creep phenomenon is more remarkable, and accurate experimental data can be obtained in time.

Description

Technical Field

[0001] This invention belongs to the field of creep testing technology and relates to a convenient creep testing device for rubber materials. Background Technology

[0002] Creep refers to the phenomenon where the strain of a solid material increases over time while the stress remains constant. Plastic deformation usually occurs after the stress exceeds the elastic limit, while creep can occur even when the stress is below the elastic limit, provided the stress is applied for a sufficiently long time.

[0003] Viscoelastic materials such as rubber, asphalt, concrete, and energetic materials inevitably undergo creep under their own weight or external loads during use and storage. This creep causes internal damage and structural deformation, affecting the integrity of the entire structure and even leading to safety accidents. Therefore, studying the creep effect of viscoelastic materials is essential, especially for rubber materials in solid rocket motors. Current experimental techniques involve applying a constant stress to the sample on a simple support, then using stress sensors to collect the stress in real time. The magnitude of the load decay is used to determine whether the sample has fractured, and the time-load curve is recorded simultaneously.

[0004] Regarding the aforementioned related technologies, the inventors believe that the following defects exist:

[0005] Under existing testing conditions, when a tensile force is applied to the specimen, stress shift and large frictional force often occur between the tie rod and the base, resulting in a significant reduction in the tensile stress on the specimen and insignificant creep phenomenon, which is not conducive to obtaining accurate experimental data in a timely manner. Summary of the Invention

[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a convenient rubber material creep testing device that significantly reduces the friction between the tie rod and the bottom of the square frame, making the creep phenomenon more significant and facilitating the timely acquisition of accurate experimental data.

[0007] The solution of the present invention is:

[0008] A portable creep testing device for rubber materials includes a square frame, a fixed clamp, a movable clamp, a tie rod, a linear bearing, a limit frame, a creep detection component, and a tensile stress adjustment component;

[0009] The square frame is a vertically placed frame structure; the fixed clamp is located on the lower surface of the upper frame of the square frame; the movable clamp is located below the fixed clamp; the linear bearing is located on the upper surface of the lower frame of the square frame; the pull rod is vertically installed at the bottom of the movable clamp, and after the bottom of the pull rod slides with the linear bearing, it passes downward through the lower frame of the square frame; the creep detection component and the limiting frame are both installed below the square frame and are located on opposite sides of the pull rod; the tensile stress adjustment component is installed at the bottom of the pull rod; the top of the test sample is fixed on the fixed clamp; the bottom of the test sample is fixed on the movable clamp.

[0010] In the aforementioned portable rubber material creep testing device, the pull rod slides vertically relative to the linear bearing; the limiting frame prevents the pull rod from rotating during vertical sliding; the creep detection component detects the creep of the sample under tensile stress without contacting the pull rod; both the linear bearing and the pull rod are made of steel, and all accessories of the linear bearing and the pull rod have a chrome-plated layer on their outer surfaces.

[0011] In the aforementioned portable rubber material creep testing device, the linear bearing includes a bearing housing and a bearing sleeve;

[0012] The bearing cylinder extends vertically through the bottom of the square frame; the bearing seat is integrally formed on the top of the bearing cylinder; the bearing seat is fixed to the upper surface of the lower frame of the square frame by multiple sets of bolts; and multiple rows of vertically arranged balls are embedded in the inner peripheral wall of the bearing cylinder, which can roll freely and abut against the outer peripheral wall of the tie rod.

[0013] In the aforementioned portable rubber material creep testing device, the limiting frame has a Z-shaped structure; the limiting frame includes a top rod, a vertical rod, and a bottom rod;

[0014] The top rod and the bottom rod are both arranged horizontally; the top rod and the bottom rod are respectively fixed to both ends of the vertical rod and are located on both sides of the vertical rod; the top rod is attached to and fixed to the bottom surface of the square frame; a positioning plane is provided on the side of the tie rod near the limiting frame; a gap of 0.5-1 mm is left between the positioning plane and the end of the bottom rod.

[0015] In the aforementioned portable rubber material creep testing device, the bottom end of the base rod near the pull rod is provided with an arc surface.

[0016] In the aforementioned portable rubber material creep testing device, the creep detection component includes a support, a displacement sensor, and a magnetic scale;

[0017] The support is arranged vertically and its top is fixed to the bottom surface of the square frame; the displacement sensor is fixed to the support; the magnetic scale is arranged vertically and fixed to the tie rod; the sensing surface of the displacement sensor is spaced apart from and parallel to the magnetic scale; the displacement sensor detects and records the creep of the sample under tensile stress by sensing the vertical displacement of the magnetic scale.

[0018] In the aforementioned portable rubber material creep testing device, a mounting plane is provided on the side of the pull rod near the displacement sensor; the magnetic scale is fixed on the mounting plane.

[0019] In the aforementioned portable rubber material creep testing device, the tensile stress adjustment component includes a hook tray and multiple adjustment weights;

[0020] The bottom of the pull rod is provided with a hook hole; the top of the hook tray can be detachably hung in the hook hole; one side of the adjusting weight is provided with a notch, and multiple adjusting weights are stacked and placed on the support plate at the bottom of the hook tray.

[0021] In the aforementioned portable rubber material creep testing device, both ends of the test sample are dumbbell-shaped structures; the bottom of the fixed clamp is provided with a first slot adapted to the dumbbell-shaped structure; and the top of the movable clamp is provided with a second slot adapted to the dumbbell-shaped structure.

[0022] In the aforementioned portable rubber material creep testing device, the square frame includes an upper beam plate, a lower beam plate, and two columns;

[0023] The upper beam plate is horizontally arranged and the tops of the two columns are fixed at both ends respectively; the lower beam plate is horizontally arranged and the bottoms of the two columns are fixed at both ends respectively; a vertically arranged perforated pin is also provided in the middle of the upper surface of the upper beam plate.

[0024] The advantages of this invention compared to the prior art are:

[0025] (1) The present invention combines the limiting frame to limit and block the pull rod, effectively preventing the pull rod from rotating during vertical sliding, thereby effectively reducing the stress offset of the pull rod, that is, the pull rod will not easily have a skewed tendency when sliding;

[0026] (2) The present invention, combined with the added linear bearing, greatly reduces the friction between the tie rod and the bottom of the square frame, so that the tensile stress on the sample is almost equal to the weight of the tensile stress adjustment component. The tensile stress will not be greatly lost or reduced during the transmission process, making the creep phenomenon more significant. This makes it convenient for the creep detection component to detect the creep of the sample under tensile stress without contacting the tie rod, which is conducive to timely acquisition of accurate experimental data.

[0027] (3) The device of the present invention has a simple structure, small size, is easy to use and stable operation, and is more suitable for efficient creep testing of rubber materials. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the convenient rubber material creep testing device of the present invention. Detailed Implementation

[0029] The present invention will be further described below with reference to the embodiments.

[0030] This invention provides a convenient creep testing device for rubber materials, which significantly reduces the friction between the tie rod and the bottom of the square frame, making the creep phenomenon more significant and facilitating the timely acquisition of accurate experimental data.

[0031] Portable creep testing device for rubber materials, such as Figure 1 As shown, the system specifically includes a square frame 1, a fixed clamp 2, a movable clamp 3, a pull rod 4, a linear bearing 5, a limiting frame 6, a creep detection component 7, and a tensile stress adjustment component 8. The square frame 1 is a vertically placed frame structure; the fixed clamp 2 is located on the lower surface of the upper frame of the square frame 1; the movable clamp 3 is located below the fixed clamp 2; the linear bearing 5 is located on the upper surface of the lower frame of the square frame 1; the pull rod 4 is vertically installed at the bottom of the movable clamp 3, and after sliding engagement with the linear bearing 5, it passes downward through the lower frame of the square frame 1; the creep detection component 7 and the limiting frame 6 are both installed below the square frame 1 and are located on opposite sides of the pull rod 4; the tensile stress adjustment component 8 is installed at the bottom of the pull rod 4; the top of the test sample is fixed to the fixed clamp 2; and the bottom of the test sample is fixed to the movable clamp 3.

[0032] The square frame 1 includes an upper beam 11, a lower beam 12, and two columns 13. The upper beam 11 is horizontally arranged and its two ends are respectively fixed to the top of the two columns 13; the lower beam 12 is horizontally arranged and its two ends are respectively fixed to the bottom of the two columns 13; a vertically arranged perforated pin is also provided in the middle of the upper surface of the upper beam 11.

[0033] Both ends of the test sample are dumbbell-shaped structures; the bottom of the fixed clamp 2 is provided with a first slot 21 adapted to the dumbbell-shaped structure; the top of the movable clamp 3 is provided with a second slot 31 adapted to the dumbbell-shaped structure.

[0034] The pull rod 4 slides vertically relative to the linear bearing 5; the limiting bracket 6 prevents the pull rod 4 from rotating during vertical sliding; the creep detection component 7 detects the creep of the sample under tensile stress without contacting the pull rod 4; both the linear bearing 5 and the pull rod 4 are made of steel, and all the outer surfaces of the linear bearing 5 and the pull rod 4 are chrome-plated.

[0035] In this invention, the linear bearing 5 includes a bearing housing 51 and a bearing sleeve 52. The bearing sleeve 52 extends vertically through the bottom of the square frame 1; the bearing housing 51 is integrally formed on the top of the bearing sleeve 52; the bearing housing 51 is fixed to the upper surface of the lower frame of the square frame 1 by multiple sets of bolts; and multiple vertical rows of freely rolling balls are embedded in the inner peripheral wall of the bearing sleeve 52, abutting against the outer peripheral wall of the tie rod 4.

[0036] The limiting frame 6 has a Z-shaped structure and includes a top rod 61, a vertical rod 62, and a bottom rod 63. Both the top rod 61 and the bottom rod 63 are horizontally arranged. The top rod 61 and the bottom rod 63 are fixed to both ends of the vertical rod 62 and are located on opposite sides of the vertical rod 62. The top rod 61 is attached to and fixed to the bottom surface of the square frame 1. A positioning plane 41 is provided on the side of the pull rod 4 near the limiting frame 6. A gap of 0.5-1 mm is left between the positioning plane 41 and the end of the bottom rod 63. The bottom end of the bottom rod 63 near the pull rod 4 has an arc surface 631.

[0037] The creep detection assembly 7 includes a bracket 71, a displacement sensor 72, and a magnetic scale 73. The bracket 71 is vertically arranged and its top is fixed to the bottom surface of the square frame 1; the displacement sensor 72 is fixed to the bracket 71; the magnetic scale 73 is vertically arranged and fixed to the tie rod 4; the sensing surface of the displacement sensor 72 is spaced apart from and parallel to the magnetic scale 73; the displacement sensor 72 detects and records the creep of the sample under tensile stress by sensing the vertical displacement of the magnetic scale 73. A mounting plane 42 is provided on the side of the tie rod 4 near the displacement sensor 72; the magnetic scale 73 is fixed to the mounting plane 42.

[0038] The tensile stress adjustment assembly 8 includes a hook tray 81 and multiple adjustment weights 82. The bottom of the pull rod 4 is provided with a hook hole 43; the top of the hook tray 81 is detachably hooked into the hook hole 43; one side of the adjustment weight 82 is provided with a notch, and multiple adjustment weights 82 are stacked and placed on the support plate at the bottom of the hook tray 81.

[0039] Example

[0040] This application discloses a portable creep testing device for rubber materials. (Refer to...) Figure 1The portable rubber material creep testing device includes a square frame 1, a fixed clamp 2, a movable clamp 3, a pull rod 4, a linear bearing 5, a limiting frame 6, a creep detection component 7, and a tensile stress adjustment component 8. The two ends of the sample to be tested are detachably clamped to the fixed clamp 2 and the movable clamp 3, respectively. The fixed clamp 2 is fixed to the inner top of the square frame 1, and the movable clamp 3 is fixed to the top of the pull rod 4 and located directly below the fixed clamp 2. The linear bearing 5 is fixed to the bottom of the square frame 1. The pull rod 4 is vertically slidably mounted and passes through the linear bearing 5. The creep detection component 7 and the limiting frame 6 are both installed below the square frame 1 and located on opposite sides of the pull rod 4. The tensile stress adjustment component 8 is installed at the bottom of the pull rod 4. The limiting frame 6 is used to prevent the pull rod 4 from rotating during vertical sliding. The creep detection component 7 is used to detect the creep of the sample under tensile stress without contacting the pull rod 4.

[0041] To further reduce the sliding friction between the tie rod 4 and the linear bearing 5, both the linear bearing 5 and the tie rod 4 are made of steel. Furthermore, all the outer surfaces of the linear bearing 5 and the tie rod 4 are coated with a hard, smooth, and wear-resistant chrome plating layer. The hardness, smoothness, and wear resistance of the chrome plating layer can significantly extend the service life of the tie rod 4 and the linear bearing 5.

[0042] The linear bearing 5 includes a bearing housing 51 and a bearing sleeve 52. The bearing sleeve 52 extends vertically through the bottom of the square frame 1. The bearing housing 51 is integrally formed on the top of the bearing sleeve 52. The bearing housing 51 is fixed to the bottom of the square frame 1 by multiple sets of bolts. Multiple vertical rows of balls that can roll freely and abut against the outer wall of the tie rod 4 are embedded on the inner peripheral wall of the bearing sleeve 52. The linear bearing 5 designed above has a simple structure, is firmly installed, and uses readily available parts that can be purchased directly on the market. It is also convenient for later maintenance and replacement.

[0043] In this embodiment, the limiting frame 6 has a Z-shaped structure and includes a top rod 61, a vertical rod 62, and a bottom rod 63. The top rod 61 and the bottom rod 63 are both arranged horizontally. The top rod 61 and the bottom rod 63 are respectively fixed to both ends of the vertical rod 62 and are located on two opposite sides of the vertical rod 62. The top rod 61 is attached to and fixed to the bottom surface of the square frame 1. The pull rod 4 is provided with a positioning plane 41 on the side near the limiting frame 6. A gap of 0.5-1 mm is left between the positioning plane 41 and the end of the bottom rod 63. The bottom end of the bottom rod 63 near the pull rod 4 is provided with an arc surface 631.

[0044] The limit frame 6 designed above has a simple structure and is firmly installed. The bottom rod 63 cooperates with the positioning plane 41 to effectively prevent the pull rod 4 from rotating during vertical sliding.

[0045] In this embodiment, the creep detection component 7 includes a support 71, a displacement sensor 72, and a magnetic scale 73. The support 71 is vertically arranged and its top is fixed to the bottom surface of the square frame 1. The displacement sensor 72 is fixed to the support 71, and the magnetic scale 73 is vertically arranged and fixed to the tie rod 4. The sensing surface of the displacement sensor 72 is spaced apart from and parallel to the magnetic scale 73. The displacement sensor 72 detects and records the creep of the sample under tensile stress by sensing the vertical displacement of the magnetic scale 73. The creep detection component 7 designed above has a simple structure, is easy to install, and operates stably. Moreover, it can effectively avoid contact with the tie rod 4 and the generation of resistance during the creep detection process, resulting in more accurate test results.

[0046] To facilitate the installation and fixation of the magnetic ruler 73, an installation plane 42 is provided on the side of the pull rod 4 near the displacement sensor 72. The magnetic ruler 73 is glued and fixed on the installation plane 42. The installation plane 42 and the positioning plane 41 are symmetrically arranged on both sides of the bottom of the pull rod 4.

[0047] In this embodiment, in order to facilitate the adjustment of tensile stress during the test, the tensile stress adjustment component 8 includes a hook tray 81 and multiple adjustment weights 82. The bottom of the pull rod 4 is provided with a hook hole 43, the top of the hook tray 81 is detachably hooked into the hook hole 43, and a notch is provided on one side of the adjustment weight 82. Multiple adjustment weights 82 are stacked and placed on the support plate at the bottom of the hook tray 81.

[0048] To facilitate the fabrication, installation, and disassembly of the test specimen, both ends of the specimen are dumbbell-shaped. The fixed clamp 2 and the movable clamp 3 are both square plates. The bottom of the fixed clamp 2 is provided with a first slot 21 adapted to the dumbbell-shaped structure, and the top of the movable clamp 3 is provided with a second slot 31 adapted to the dumbbell-shaped structure. The fixed clamp 2 and the movable clamp 3 designed above are easy to manufacture and are more suitable for the installation and disassembly of dumbbell-shaped specimens, eliminating the need to process the specimen into a specific shape specifically for creep testing.

[0049] In this embodiment, in order to improve the sturdiness of the square frame 1 and facilitate the installation of other components, the square frame 1 includes an upper beam plate 11, a lower beam plate 12 and two columns 13. The upper beam plate 11 is arranged horizontally and the tops of the two columns 13 are fixed at both ends respectively. The lower beam plate 12 is arranged horizontally and the bottoms of the two columns 13 are fixed at both ends respectively. A vertically arranged perforated pin 14 is also provided in the middle of the upper surface of the upper beam plate 11.

[0050] In actual operation, the tester turns on the computer in the control room, connects the displacement sensor 72 to the computer and connects it online. The test sample is fixed by the fixed clamp 2 and the movable clamp 3. An appropriate number of adjusting weights 82 are hung at the bottom of the pull rod 4 until the load required for the test is successfully applied. Then, the matching test software is run to receive and display the data information transmitted in real time by the displacement sensor 72, monitor the changes in the strain of the sample over a long period of time, and carry out creep test until the end of the test.

[0051] The beneficial technical effects of the portable rubber material creep testing device according to the embodiments of this application are roughly as follows:

[0052] Combined with the limiting and blocking effect of the limiting frame 6 on the pull rod 4, the pull rod 4 is effectively prevented from rotating during vertical sliding, thereby effectively reducing the stress offset of the pull rod 4. That is, the pull rod 4 will not easily have a tendency to tilt when sliding. In addition, the added linear bearing 5 significantly reduces the friction between the pull rod 4 and the bottom of the square frame 1, so that the tensile stress on the sample is almost equal to the weight of the tensile stress adjustment component 8. The tensile stress will not be greatly lost or reduced during transmission, making the creep phenomenon more significant. This allows the creep detection component 7 to detect the creep of the sample under tensile stress without contacting the pull rod 4, which is conducive to timely and accurate experimental data acquisition.

[0053] Moreover, the entire device has a simple structure, is compact in size, easy to use, and runs stably, making it more suitable for efficient creep testing of rubber materials.

[0054] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A portable creep testing device for rubber materials, characterized in that: It includes a square frame (1), a fixed clamp (2), a movable clamp (3), a tie rod (4), a linear bearing (5), a limit frame (6), a creep detection component (7), and a tensile stress adjustment component (8); The square frame (1) is a vertically placed frame structure; the fixed clamp (2) is located on the lower surface of the upper frame of the square frame (1); the movable clamp (3) is located below the fixed clamp (2); the linear bearing (5) is located on the upper surface of the lower frame of the square frame (1); the pull rod (4) is vertically installed at the bottom of the movable clamp (3), and after the bottom of the pull rod (4) slides with the linear bearing (5), it passes downward through the lower frame of the square frame (1); the creep detection component (7) and the limiting frame (6) are both installed below the square frame (1) and are located on opposite sides of the pull rod (4); the tensile stress adjustment component (8) is installed at the bottom of the pull rod (4); the top of the test sample is fixed on the fixed clamp (2); and the bottom of the test sample is fixed on the movable clamp (3).

2. The portable rubber material creep testing device according to claim 1, characterized in that: The pull rod (4) slides vertically relative to the linear bearing (5); the limiting frame (6) prevents the pull rod (4) from rotating during vertical sliding; the creep detection component (7) detects the creep of the sample under tensile stress without contacting the pull rod (4); both the linear bearing (5) and the pull rod (4) are made of steel, and all the outer surfaces of the linear bearing (5) and the pull rod (4) are chrome-plated.

3. The portable rubber material creep testing device according to claim 1, characterized in that: The linear bearing (5) includes a bearing housing (51) and a bearing sleeve (52); The bearing cylinder (52) extends vertically through the bottom of the square frame (1); the bearing seat (51) is integrally formed on the top of the bearing cylinder (52); the bearing seat (51) is fixed to the upper surface of the lower frame of the square frame (1) by multiple sets of bolts; and multiple rows of vertically arranged balls that can roll freely and abut against the outer wall of the tie rod (4) are embedded on the inner peripheral wall of the bearing cylinder (52).

4. The portable rubber material creep testing device according to claim 3, characterized in that: The limiting frame (6) has a Z-shaped structure; the limiting frame (6) includes a top rod (61), a vertical rod (62) and a bottom rod (63); The top rod (61) and the bottom rod (63) are both arranged horizontally; the top rod (61) and the bottom rod (63) are respectively fixed to the two ends of the vertical rod (62) and are located on both sides of the vertical rod (62); the top rod (61) is attached to and fixed to the bottom surface of the square frame (1); the tie rod (4) has a positioning plane (41) on the side near the limiting frame (6); a gap of 0.5-1 mm is left between the positioning plane (41) and the end of the bottom rod (63).

5. A portable rubber material creep testing device according to claim 4, characterized in that: The bottom end of the base rod (63) near the tie rod (4) is provided with an arc surface (631).

6. The portable rubber material creep testing device according to claim 1, characterized in that: The creep detection component (7) includes a bracket (71), a displacement sensor (72), and a magnetic scale (73); The bracket (71) is arranged vertically and its top is fixed to the bottom surface of the square frame (1); the displacement sensor (72) is fixed on the bracket (71); the magnetic ruler (73) is arranged vertically and fixed on the pull rod (4); the sensing surface of the displacement sensor (72) is spaced apart from and parallel to the magnetic ruler (73); the displacement sensor (72) detects and records the creep of the sample under tensile stress by sensing the vertical displacement of the magnetic ruler (73).

7. A portable rubber material creep testing device according to claim 6, characterized in that: The pull rod (4) has a mounting plane (42) on the side near the displacement sensor (72); the magnetic ruler (73) is fixed on the mounting plane (42).

8. The portable rubber material creep testing device according to claim 1, characterized in that: The tensile stress adjustment assembly (8) includes a hook tray (81) and multiple adjustment weights (82); The bottom of the pull rod (4) is provided with a hook hole (43); the top of the hook tray (81) is detachably attached to the hook hole (43); a notch is provided on one side of the adjusting weight (82), and multiple adjusting weights (82) are stacked and placed on the support plate at the bottom of the hook tray (81).

9. A portable rubber material creep testing device according to claim 1, characterized in that: Both ends of the test sample are dumbbell-shaped structures; the bottom of the fixed clamp (2) is provided with a first slot (21) adapted to the dumbbell-shaped structure; the top of the movable clamp (3) is provided with a second slot (31) adapted to the dumbbell-shaped structure.

10. A portable rubber material creep testing device according to claim 1, characterized in that: The square frame (1) includes an upper beam plate (11), a lower beam plate (12), and two columns (13); The upper beam plate (11) is horizontally arranged and the tops of the two columns (13) are fixed at both ends respectively; the lower beam plate (12) is horizontally arranged and the bottoms of the two columns (13) are fixed at both ends respectively; a vertically arranged perforated pin is also provided in the middle of the upper surface of the upper beam plate (11).

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