Device for testing tensile stress of carbon fiber

Abstract

The utility model belongs to the technical field of tensile stress testing, and particularly relates to a carbon fiber tensile stress testing device which comprises a bottom plate, a U-shaped plate with a downward opening is fixedly arranged in the middle of the top face of the bottom plate, a pair of symmetrically-distributed translation plates are arranged on the two sides of the U-shaped plate, and a transversely-arranged carbon fiber testing piece is arranged in the middle of the top face of the U-shaped plate. The two sides of the carbon fiber test piece are erected in the middle of the top surfaces of the pair of translation plates; a double-face rack is longitudinally arranged in the middle of the bottom face of the bottom plate, a pair of linkage gear discs which are symmetrically distributed are arranged on the two sides of the double-face rack, and the double-face rack is connected with the pair of linkage gear discs in an engaged mode. The carbon fiber tensile stress test fixture solves the problems that the two ends are not firmly fixed and measurement errors are easily caused during a carbon fiber tensile stress test, is compact in overall structural design, not only ensures the fixing stability of the two ends of the carbon fiber, but also ensures that the tensile forces at the two ends are the same, and reduces the occurrence of the measurement errors.

Description

Technical Field

[0001] The utility model belongs to the technical field of tensile stress testing, and in particular relates to a device for testing the tensile stress of carbon fibers. Background Art

[0002] A Chinese utility model patent discloses a tensile stress loading test device for epoxy-based carbon fiber composite materials, with the publication number CN102519934A. The device includes a support, which is concave in shape and has two side vertical plates, one of which has a pull ring on the inner side of one side vertical plate and a bolt through hole on the other side vertical plate. A tension spring and a first and a second fixing clamp for fixing the test sample are provided between the two side vertical plates. The first and the second fixing clamps each include a clamping portion located at one end of each clamp, a tension spring hole is provided on the other end of the first fixing clamp, and a threaded rod is provided on the other end of the second fixing clamp, and a force adjustment nut is provided on the threaded rod.

[0003] The following problems exist when testing the tensile stress of carbon fiber: 1. The two ends of the carbon fiber test piece need to be fixed to ensure its stability during the test. Currently, it is inconvenient to effectively clamp and fix the two ends; 2. When conducting the test, the method of directly pulling the two ends to break the middle is often adopted. The pulling method is inconvenient and cannot ensure that the tension at both ends is the same, which can easily cause measurement errors. Utility Model Content

[0004] In response to the above technical problems, the present invention provides a device for testing the tensile stress of carbon fibers, which solves the shortcomings of the prior art in that the two ends of the carbon fibers are not firmly fixed and measurement errors are easily caused during tensile stress testing of the carbon fibers.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A carbon fiber tensile stress testing device comprises a base plate, a U-shaped plate with a downward opening fixedly provided in the middle of the top surface of the base plate, a pair of symmetrically distributed translation plates provided on both sides of the U-shaped plate, a carbon fiber test piece placed horizontally in the middle of the top surface of the U-shaped plate, and the two sides of the carbon fiber test piece are placed on the middle of the top surfaces of the pair of translation plates;

[0007] A longitudinally placed double-sided rack is provided in the middle of the bottom surface of the base plate, and a pair of symmetrically distributed linkage gear plates are provided on both sides of the double-sided rack, and the double-sided rack is meshed and connected with the pair of linkage gear plates, and each linkage gear plate is connected to the translation plate on the corresponding side through a limiting mechanism;

[0008] A pair of circular cavities are provided on the front and rear sides of the translation plate, and a pair of positioning sliding holes connected to the circular cavities are provided on both sides of the top surface of the translation plate. A slidingly connected positioning shaft is inserted into the interior of each of the positioning sliding holes, and a positioning swing arm is fixed to the top end of each of the positioning shafts.

[0009] A first hydraulic cylinder with its telescopic end facing forward is fixedly provided in the middle of the top surface of the base plate, and a connecting block is fixedly provided at the end of the hydraulic rod of the first hydraulic cylinder, and the bottom end of the connecting block is fixedly connected to the front end of the double-sided rack; a concentrically fixed linkage shaft is provided in the middle of each linkage gear plate, and the top end of each linkage shaft is rotatably connected to the bottom surface of the base plate.

[0010] The limiting mechanism includes a limiting plate, two pairs of symmetrically distributed rectangular sliding holes are opened on both sides of the top surface of the bottom plate, the bottom surface of the linkage gear plate is provided with a slidingly connected limiting plate, and a pair of L-shaped slides are fixed at both ends of the limiting plate. The top ends of a pair of L-shaped slides slide through a pair of rectangular sliding holes on the corresponding side and are fixed to the bottom surface of the translation plate.

[0011] An elliptical pin hole is opened in the middle of the limiting plate, a limiting pin shaft is fixedly provided on one side of the bottom surface of the linkage gear plate, and the bottom end portion of the limiting pin shaft is slidably inserted in the elliptical pin hole.

[0012] A positioning threaded hole is provided at the outer end of each positioning swing arm, a threaded positioning bolt is inserted into the interior of each positioning threaded hole, a positioning pressure block is fixed to the bottom end of each positioning bolt, and the bottom surface of each positioning pressure block rests on the carbon fiber test piece.

[0013] A pair of limiting threaded holes connected to the circular cavity are inserted on the front and rear sides of the translation plate, and a threaded limiting bolt is inserted inside each of the limiting threaded holes. The inner end of each of the limiting bolts is fixed with a limiting pin, and the middle section of each of the positioning shafts is provided with an L-shaped pin hole, and the inner end of each of the limiting pins is slidably inserted in the corresponding L-shaped pin hole.

[0014] A concentrically placed helical gear is provided inside the circular cavity. The helical gear is sleeved on the bottom end of the corresponding positioning shaft and is concentrically fixed to the positioning shaft.

[0015] A pair of positioning sliding holes that pass through the circular cavity transversely are opened on the two side walls of the translation plate. A single-sided rack that slides through the interior of each positioning sliding hole is inserted, and each single-sided rack is meshed and slidably connected with the helical gear on the corresponding side.

[0016] A circular groove is provided in the middle of the back side of the translation plate, and a second hydraulic cylinder with the telescopic end facing outward is fixed inside each of the circular grooves. A connecting long rod is fixed at the end of the hydraulic telescopic rod of each of the second hydraulic cylinders, and both ends of each connecting long rod are fixedly connected to the outer end of the single-sided rack on the corresponding side.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. In the present invention, since the limiting pin and the L-shaped pin hole form a limiting effect, the positioning shaft first rotates inward and then slides downward, and then drives the positioning pressure block to rest on the carbon fiber test piece through the positioning swing arm, thereby increasing the stability of the carbon fiber test piece fixation, and the carbon fiber test piece is always kept on the same horizontal plane. Therefore, the test results are accurate, true, and referenceable, which to a large extent ensures the safety and stability of the carbon fiber testing process.

[0019] 2. In the present invention, the limit pin on the linkage gear disk and the elliptical pin hole on the limit plate form a limiting effect, so that a pair of translation plates move away from each other, driving the carbon fiber test piece to slowly stretch and lengthen. When it reaches a certain extent, the carbon fiber test piece breaks, and the tensile stress value of the carbon fiber is measured, thereby obtaining more accurate data, better evaluating the quality of the carbon fiber, and providing an accurate experimental basis for improving the performance of the carbon fiber and improving the production process.

[0020] In summary, the utility model solves the problem that the two ends of the carbon fiber are not firmly fixed and easily cause measurement errors during tensile stress testing. The overall structural design is compact, which not only ensures the stability of the fixation of the two ends of the carbon fiber, but also ensures that the tension at both ends is the same, reducing the occurrence of measurement errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0022] The structures, proportions, sizes, etc. illustrated in this specification are intended solely to complement the contents disclosed herein and to facilitate understanding and reading by persons skilled in the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in size, provided they do not affect the efficacy and objectives of the present invention, shall remain within the scope of the technical contents disclosed herein.

[0023] Figure 1 This is a schematic diagram of the main structure of the utility model;

[0024] Figure 2 This is an explosion diagram of the utility model;

[0025] Figure 3 This is a bottom view schematic diagram of the present utility model;

[0026] Figure 4 This is a schematic diagram of the main cutaway view of the present invention;

[0027] Figure 5 This is a schematic diagram of the testing method of the present utility model.

[0028] Among them: 1 is the base plate; 11 is the U-shaped plate; 12 is the carbon fiber test piece; 13 is the double-sided rack; 14 is the linkage gear plate; 15 is the limit plate; 16 is the L-shaped slide; 17 is the first hydraulic cylinder; 18 is the connecting block; 2 is the translation plate; 21 is the positioning shaft; 22 is the positioning swing arm; 23 is the positioning bolt; 24 is the positioning pressure block; 25 is the bevel gear; 26 is the limit bolt; 27 is the single-sided rack; 28 is the second hydraulic cylinder; 29 is the connecting long rod. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. These descriptions are only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0030] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0031] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0033] Example 1: This example provides a carbon fiber tensile stress testing device, see Figure 1-4 Specifically, it includes a base plate 1, a U-shaped plate 11 with an opening facing downward is fixed in the middle of the top surface of the base plate 1, a pair of symmetrically distributed translation plates 2 are provided on both sides of the U-shaped plate 11, and a horizontally placed carbon fiber test piece 12 is provided in the middle of the top surface of the U-shaped plate 11, and both sides of the carbon fiber test piece 12 are placed in the middle of the top surface of the pair of translation plates 2.

[0034] A longitudinally placed double-sided rack 13 is provided in the middle of the bottom surface of the base plate 1, and a pair of symmetrically distributed linkage gear plates 14 are provided on both sides of the double-sided rack 13, and the double-sided rack 13 is meshed and connected with the pair of linkage gear plates 14, and each linkage gear plate 14 is connected to the translation plate 2 on the corresponding side through a limiting mechanism.

[0035] A pair of circular cavities are opened on the front and rear sides of the translation plate 2, and a pair of positioning sliding holes connected to the circular cavities are opened on both sides of the top surface of the translation plate 2. A slidingly connected positioning shaft 21 is inserted into the inside of each positioning sliding hole, and a positioning swing arm 22 is fixed to the top end of each positioning shaft 21.

[0036] In the specific implementation process, Figure 2 and Figure 4 As shown, a pair of limiting threaded holes connected to the circular cavity are inserted on the front and rear sides of the translation plate 2, and a threaded limiting bolt 26 is inserted inside each limiting threaded hole. The inner end of each limiting bolt 26 is fixed with a limiting pin, and the middle section of each positioning shaft 21 is provided with an L-shaped pin hole, and the inner end of each limiting pin is slidably inserted in the corresponding L-shaped pin hole.

[0037] A concentrically placed helical gear 25 is provided inside the circular cavity. The helical gear 25 is sleeved on the bottom end of the corresponding positioning shaft 21 and is concentrically fixed to the positioning shaft 21. Due to the limiting effect formed by the limiting pin and the L-shaped pin hole, the positioning shaft 21 first rotates inward and then slides downward, and then drives the positioning pressure block 24 to press against the carbon fiber test piece 12 through the positioning swing arm 22. In the specific implementation process, Figure 2 and Figure 4As shown, a pair of positioning holes extending transversely through the circular cavity are formed on the two side walls of the translation plate 2. Each positioning hole is fitted with a single-sided rack 27 that slides through it. Each single-sided rack 27 is meshed and slidably connected to the corresponding helical gear 25. The meshing of the single-sided rack 27 drives the helical gear 25 and the positioning shaft 21 to rotate.

[0038] A circular groove is defined in the middle of the opposing back surfaces of the pair of translation plates 2. A second hydraulic cylinder 28, with its telescopic end facing outward, is secured within each groove. A connecting rod 29 is secured to the end of the hydraulic telescopic rod of each second hydraulic cylinder 28. Both ends of each connecting rod 29 are fixedly connected to the outer end of the corresponding single-sided rack 27. The hydraulic telescopic rod of the second hydraulic cylinder 28 slowly retracts, driving the single-sided rack 27 to slide along the positioning slide hole via the connecting rod 29.

[0039] It should be noted that in this embodiment, a threaded positioning hole is formed at the outer end of each positioning swing arm 22, and a threaded positioning bolt 23 is inserted into each positioning threaded hole. A positioning pressure block 24 is fixed to the bottom end of each positioning bolt 23, and the bottom surface of each positioning pressure block 24 abuts against the carbon fiber test piece 12. The height of the positioning pressure block 24 is adjusted by rotating the positioning bolt 23 according to the thickness of the carbon fiber test piece 12.

[0040] Embodiment 2: In embodiment 1, there is still the problem of inconvenience in translation of the pair of translation plates 2. Therefore, based on embodiment 1, this embodiment further includes:

[0041] In the specific implementation process, Figure 2 and Figure 3As shown, a first hydraulic cylinder 17, with its telescopic end facing forward, is fixed to the center of the top surface of the base plate 1. A connecting block 18 is fixed to the end of the hydraulic rod of the first hydraulic cylinder 17. The bottom end of the connecting block 18 is fixed to the front end of the double-sided rack 13. A concentrically fixed linkage shaft is installed in the center of each linkage gear plate 14. The top end of each linkage shaft is rotatably connected to the bottom surface of the base plate 1. The hydraulic telescopic rod of the first hydraulic cylinder 17 slowly extends, driving the double-sided rack 13 to slide forward through the connecting block 18. The meshing of the double-sided rack 13 drives the pair of linkage gear plates 14 to rotate in opposite directions. The limiting mechanism includes a limiting plate 15. Two pairs of symmetrically distributed rectangular sliding holes are defined on either side of the top surface of the base plate 1. The bottom surface of the linkage gear plate 14 is slidably connected to the limiting plate 15. A pair of L-shaped slides 16 are fixed to each end of the limiting plate 15. The top ends of the L-shaped slides 16 slide through the corresponding pair of rectangular sliding holes and are fixed to the bottom surface of the translation plate 2. An elliptical pinhole is provided in the center of the limit plate 15. A limit pin is fixed to one side of the bottom surface of the linkage gear plate 14, and the bottom end of the limit pin slides into the elliptical pinhole. When the linkage gear plate 14 rotates, the limit pin on the linkage gear plate 14 and the elliptical pinhole on the limit plate 15 form a limit function, driving the L-shaped slide plate 16 and the translation plate 2 to slide outward along the rectangular slide hole, causing the pair of translation plates 2 to move away from each other, causing the carbon fiber test piece 12 to slowly stretch and lengthen.

[0042] Example 3: See Figure 5 Specifically, the working principle and operation method of the utility model are as follows:

[0043] Step 1: When conducting a carbon fiber tensile stress test, place the carbon fiber test piece 12 in the center of the top surface of the U-shaped plate 11, and place both sides of the carbon fiber test piece 12 in the middle of the top surface of a pair of translation plates 2. Then, according to the thickness of the carbon fiber test piece 12, adjust the height position of the positioning block 24 by rotating the positioning bolt 23.

[0044] Step 2: Synchronously start a pair of second hydraulic cylinders 28. The hydraulic telescopic rod of the second hydraulic cylinder 28 is slowly shortened, and the single-sided rack 27 is driven to slide along the positioning slide hole by connecting the long rod 29. The single-sided rack 27 is engaged to drive the bevel gear 25 and the positioning shaft 21 to rotate. Since the limit pin and the L-shaped pin hole form a limiting effect, the positioning shaft 21 first rotates inward and then slides downward, and then drives the positioning pressure block 24 to rest on the carbon fiber test piece 12 through the positioning swing arm 22.

[0045] Step three, start the first hydraulic cylinder 17, the hydraulic telescopic rod of the first hydraulic cylinder 17 slowly extends, driving the double-sided rack 13 to slide forward through the connecting block 18, and the double-sided rack 13 engages to drive a pair of linked gear plates 14 to rotate in opposite directions.

[0046] Step four: when the linkage gear plate 14 rotates, the limit pin on the linkage gear plate 14 and the elliptical pin hole on the limit plate 15 form a limiting effect, driving the L-shaped slide plate 16 and the translation plate 2 to slide outward along the rectangular slide hole, so that a pair of translation plates 2 move away from each other, driving the carbon fiber test piece 12 to slowly stretch and lengthen. When it reaches a certain extent, the carbon fiber test piece 12 breaks.

[0047] The above only describes in detail the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by ordinary technicians in this field, various changes can be made without departing from the purpose of the present invention, and various changes should be included in the scope of protection of the present invention.

Claims

1. A device for testing the tensile stress of carbon fiber, characterized by: The invention comprises a bottom plate (1), a U-shaped plate (11) with an opening facing downward is fixedly provided in the middle of the top surface of the bottom plate (1), a pair of symmetrically distributed translation plates (2) are provided on both sides of the U-shaped plate (11), a carbon fiber test piece (12) placed transversely is provided in the middle of the top surface of the U-shaped plate (11), and both sides of the carbon fiber test piece (12) are placed in the middle of the top surface of the pair of translation plates (2); A longitudinally placed double-sided rack (13) is provided in the middle of the bottom surface of the base plate (1), and a pair of symmetrically distributed linkage gear plates (14) are provided on both sides of the double-sided rack (13), and the double-sided rack is meshedly connected to the pair of linkage gear plates (14), and each linkage gear plate (14) is connected to the translation plate (2) on the corresponding side through a limiting mechanism; A pair of circular cavities are provided on the front and rear sides of the translation plate (2), and a pair of positioning sliding holes connected to the circular cavities are provided on both sides of the top surface of the translation plate (2). A slidably connected positioning shaft (21) is inserted into the interior of each positioning sliding hole, and a positioning swing arm (22) is fixed to the top end of each positioning shaft (21).

2. The device for testing carbon fiber tensile stress according to claim 1, characterized in that: A first hydraulic cylinder (17) with its telescopic end facing forward is fixedly provided in the middle of the top surface of the base plate (1), a connecting block (18) is fixedly provided at the end of the hydraulic rod of the first hydraulic cylinder (17), and the bottom end of the connecting block (18) is fixedly connected to the front end of the double-sided rack (13); a concentrically fixed linkage shaft is provided in the middle of each linkage gear plate (14), and the top end of each linkage shaft is rotatably connected to the bottom surface of the base plate (1).

3. The device for testing carbon fiber tensile stress according to claim 1, characterized in that: The limiting mechanism comprises a limiting plate (15), two pairs of symmetrically distributed rectangular sliding holes are opened on both sides of the top surface of the bottom plate (1), the bottom surface of the linkage gear plate (14) is provided with a slidably connected limiting plate (15), and a pair of L-shaped slide plates (16) are fixed at both ends of the limiting plate (15), and the top ends of the pair of L-shaped slide plates (16) slide through the pair of rectangular sliding holes on the corresponding side and are fixed to the bottom surface of the translation plate (2).

4. The device for testing carbon fiber tensile stress according to claim 3, characterized in that: An elliptical pin hole is provided in the middle of the limiting plate (15), and a limiting pin shaft is fixedly provided on one side of the bottom surface of the linkage gear plate (14), and the bottom end of the limiting pin shaft is slidably inserted into the elliptical pin hole.

5. The device for testing carbon fiber tensile stress according to claim 1, characterized in that: A positioning threaded hole is provided at the outer end of each positioning swing arm (22), a threaded positioning bolt (23) is inserted into the interior of each positioning threaded hole, a positioning pressure block (24) is fixed to the bottom end of each positioning bolt (23), and the bottom surface of each positioning pressure block (24) abuts against the carbon fiber test piece (12).

6. The device for testing carbon fiber tensile stress according to claim 1, characterized in that: A pair of limiting threaded holes connected to the circular cavity are inserted on the front and rear sides of the translation plate (2), and a threaded limiting bolt (26) is inserted inside each of the limiting threaded holes. A limiting pin is fixed to the inner end of each of the limiting bolts (26). An L-shaped pin hole is opened in the middle section of each of the positioning shafts (21), and the inner end of each of the limiting pins is slidably inserted into the corresponding L-shaped pin hole.

7. The device for testing carbon fiber tensile stress according to claim 1, characterized in that: A concentrically placed helical gear (25) is provided inside the circular cavity. The helical gear (25) is sleeved on the bottom end of the corresponding positioning shaft (21) and is concentrically fixed to the positioning shaft (21).

8. The device for testing carbon fiber tensile stress according to claim 1, characterized in that: A pair of positioning sliding holes that pass through the circular cavity transversely are provided on both side walls of the translation plate (2), and a single-sided rack (27) that slides through the interior of each positioning sliding hole is inserted, and each single-sided rack (27) is meshed and slidably connected with the helical gear (25) on the corresponding side.

9. The device for testing carbon fiber tensile stress according to claim 1, characterized in that: A circular groove is provided in the middle of the back side of the translation plate (2), and a second hydraulic cylinder (28) with its telescopic end facing outward is fixed inside each of the circular grooves. A connecting rod (29) is fixed at the end of the hydraulic telescopic rod of each of the second hydraulic cylinders (28), and both ends of each connecting rod (29) are fixed to the outer end of the single-sided rack (27) on the corresponding side.

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