A fiber tensile modulus test fixture

Abstract

The utility model relates to composite material detection technical field especially is related to a kind of fiber tensile modulus test tool, including base, vertical moving mechanism is equipped on base, and the moving part of vertical moving mechanism is installed with horizontal mounting bracket;Horizontal mounting bracket includes the first mounting bracket slidable connection with the moving part of vertical moving mechanism, and the first mounting bracket one end extends with second mounting bracket, and extensometer is slidably installed on second mounting bracket;The top surface and bottom surface of second mounting bracket are both equipped with inserting slot, further including the telescopic plate installed in the outer side of second mounting bracket, and the top and bottom of telescopic plate are respectively fixed with multiple inserting rods, and each inserting rod is slidably inserted with each inserting slot;Further including compression spring, and the both ends of compression spring are respectively fixed with the outer side of second mounting bracket and the inner side of telescopic plate;The utility model installs extensometer on horizontal mounting bracket, and the weight of extensometer is supported using tool body, avoid the influence of extensometer deadweight on detection result.

Description

Technical Field

[0001] This utility model relates to the field of composite material testing technology, and in particular to a fiber tensile modulus testing fixture. Background Technology

[0002] In the field of composite materials, carbon fiber multifilament is an important raw material for composite materials. Testing the tensile properties of carbon fiber multifilament is a key step in evaluating whether the performance of composite material raw materials meets the standards. The tensile properties test of carbon fiber multifilament includes tests for strength, modulus, and elongation at break. During the test, an extensometer is used to obtain strain data. The extensometer is suspended in the middle of the sample and the strain is collected as the sample deforms.

[0003] However, since the fiber multifilament sample is relatively weak, the extensometer is suspended by the fiber alone. First, the fiber will deform due to the weight of the extensometer, affecting the test results. Second, if the fiber multifilament sample breaks, the extensometer will fall and be damaged. As a testing instrument, the extensometer needs to be reused, not a disposable item.

[0004] For example, the extensometer with model number 3542-050M-050-ST has a downward-opening snap-fit ​​groove at its tail, which can be used to fix the extensometer to a bracket. The advantage of this operation is that it can minimize the influence of the extensometer's own weight on the test results and ensure that the extensometer does not fall after the test. However, this operation cannot adjust the clamping angle of the extensometer's blade on the sample, which affects the test results.

[0005] Therefore, in order to address the above problems, this utility model urgently needs to provide a fiber tensile modulus testing fixture. Utility Model Content

[0006] The purpose of this utility model is to provide a fiber tensile modulus testing fixture. By fixing the extensometer on a horizontal mounting frame, it solves the problems in the prior art such as the large influence of the extensometer's own weight during fiber multifilament sample testing and the extensometer falling and being damaged after the sample breaks.

[0007] A fiber tensile modulus testing fixture includes a base, a vertical moving mechanism on the base, a horizontal mounting frame on the moving part of the vertical moving mechanism, and an extensometer fixedly connected to the horizontal mounting frame.

[0008] The extensometer has a first sensor and a second sensor for measuring height detachably installed on one side of the upper and lower blades, respectively. A third sensor for measuring the height of the horizontal mounting bracket is also installed on the bottom surface of the horizontal mounting bracket.

[0009] It also includes a computing module and a controller, a first sensor, a second sensor, a third sensor and a computing module electrically connected, a computing module and a controller electrically connected, and a vertical moving mechanism and a controller electrically connected.

[0010] Furthermore, the horizontal mounting frame includes a first mounting frame slidably connected to the moving part of the vertical moving mechanism, and a second mounting frame extending horizontally from one end of the first mounting frame in the vertical direction, on which the extensometer is slidably mounted.

[0011] Furthermore, the top and bottom surfaces of the second mounting bracket are provided with multiple insertion slots that are wider on the outside and narrower on the inside. It also includes a telescopic plate installed on the outside of the second mounting bracket. The top and bottom of the telescopic plate are respectively fixed with multiple insertion rods that match the insertion slots one by one. Each insertion rod is slidably inserted into each insertion slot. It also includes a compression spring. The two ends of the compression spring are respectively fixed to the outer side of the second mounting bracket and the inner side of the telescopic plate, and are used to push the telescopic plate outward.

[0012] Furthermore, an adjustment elongated hole is cut along the length direction on the side surface of the first mounting bracket, and the first mounting bracket is adjustablely connected to the moving part of the vertical moving mechanism through the adjustment elongated hole.

[0013] Furthermore, a guide slope is provided between the top surface and the outer side of the telescopic plate to facilitate the snapping groove of the telescopic plate and the second mounting bracket into the extensometer.

[0014] Furthermore, the vertical moving mechanism includes a support frame mounted above the base, in which a vertical screw and a guide post are vertically mounted. The vertical screw and the support frame are rotatably mounted, and a drive motor is connected to the top. The guide post is fixedly connected to the support frame. It also includes a sliding plate, which is mounted on the guide post and screwed to the vertical screw. A horizontal mounting bracket is mounted on one side of the sliding plate.

[0015] Furthermore, it also includes a locking nut, one end of which passes through the sliding plate and the horizontal mounting bracket from one side, and is then screwed in on the other side by a locking washer.

[0016] Furthermore, the height of the vertical lead screw is 300mm.

[0017] Furthermore, the distance between the inner side of the second mounting bracket and the outer side of the telescopic plate is 10-30mm.

[0018] Furthermore, the first, second, and third sensors are all height or distance sensors.

[0019] The fiber tensile modulus testing fixture provided by this utility model has the following advantages compared with the prior art:

[0020] The fiber tensile modulus testing fixture provided by this utility model mounts the extensometer on a horizontal mounting frame, with the fixture body bearing the weight of the extensometer. When the fiber strength is less than the weight of the extensometer itself, the weight of the extensometer is prevented from affecting the test results. Even after the sample breaks, the extensometer, supported by the horizontal mounting frame, will not fall to the ground and cause unnecessary damage. Furthermore, in this utility model, the height of the horizontal mounting frame is adjusted under the control of a controller through the cooperation of a first, second, and third sensor. This controls the height of the extensometer. When the fiber sample is stretched, the change in length of the test area inevitably causes the upper and lower blades of the extensometer to shift vertically. Adjusting the vertical height of the extensometer ensures that the blades remain perpendicular to the direction of fiber stress, resulting in more accurate test results. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram (three-dimensional view) of the fiber tensile modulus testing fixture described in this utility model;

[0023] Figure 2 This is a schematic diagram (perspective view) of the horizontal mounting bracket described in this utility model;

[0024] Figure 3 This is a schematic diagram (top view) of the horizontal mounting bracket described in this utility model.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Base; 201. Support frame; 202. Vertical lead screw; 203. Guide post; 204. Drive motor; 205. Sliding plate; 301. First mounting bracket; 3011. Adjustment elongated hole; 302. Second mounting bracket; 3021. Insertion slot; 3022. Telescopic plate; 3023. Insertion rod; 3024. Compression spring; 4. Extensometer; 5. Locking nut. Detailed Implementation

[0027] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0028] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] like Figure 1 As shown, the present invention provides a fiber tensile modulus testing fixture, including a base 1, a vertical moving mechanism on the base 1, a horizontal mounting frame on the moving part of the vertical moving mechanism, and an extensometer 4 fixedly connected to the horizontal mounting frame.

[0031] The extensometer 4 has a first sensor and a second sensor for measuring height detachably installed on one side of the upper and lower blades, respectively. A third sensor for measuring the height of the horizontal mounting bracket is also installed on the bottom surface of the horizontal mounting bracket.

[0032] It also includes a computing module and a controller, a first sensor, a second sensor, a third sensor and a computing module electrically connected, a computing module and a controller electrically connected, and a vertical moving mechanism and a controller electrically connected.

[0033] The fiber tensile modulus testing fixture provided by this utility model mounts the extensometer 4 on a horizontal mounting frame. The fixture body bears the weight of the extensometer. When the fiber strength is less than the weight of the extensometer 4 itself, the weight of the extensometer 4 is prevented from affecting the test results. After the sample breaks, the extensometer 4, supported by the horizontal mounting frame, will not fall to the ground and cause unnecessary damage. In this utility model, through the cooperation of the first, second, and third sensors, the height of the horizontal mounting frame is adjusted under the control of the controller, thereby controlling the height of the extensometer 4. When the fiber sample is stretched, due to the change in the length of the test part, the clamping point of the sample held by the upper and lower blades of the extensometer 4 will inevitably shift vertically, causing the clamping direction of the upper and lower blades of the extensometer 4 to shift. At this time, the controller automatically adjusts the rotation of the vertical screw according to the height data of the first, second, and third sensors, thereby adjusting the vertical height of the extensometer 4. This ensures that the blades of the extensometer 4 are always perpendicular to the direction of fiber force, making the test results more accurate.

[0034] like Figure 1 , Figure 2 , Figure 3 As shown, the horizontal mounting frame includes a first mounting frame 301 that is slidably connected to the moving part of the vertical moving mechanism. One end of the first mounting frame 301 extends horizontally in the vertical direction to a second mounting frame 302, and the extensometer 4 is slidably mounted on the second mounting frame 302.

[0035] like Figure 2 , Figure 3 As shown, the top and bottom surfaces of the second mounting bracket 302 are provided with multiple insertion slots 3021 that are wider on the outside and narrower on the inside. It also includes a telescopic plate 3022 installed on the outside of the second mounting bracket 302. The top and bottom of the telescopic plate 3022 are respectively fixedly connected with multiple insertion rods 3023 that match the insertion slots 3021 one by one. Each insertion rod 3023 is slidably inserted into each insertion slot 3021. It also includes a compression spring 3024. The two ends of the compression spring 3024 are respectively fixedly connected to the outer side of the second mounting bracket 302 and the inner side of the telescopic plate 3022, and are used to push the telescopic plate 3022 outward.

[0036] In this invention, the position of the telescopic plate 3022 can be adjusted by the interlocking slot 3021 and the interlocking rod 3023, thereby adjusting the overall width of the second mounting bracket 302 to accommodate extensometers with mounting grooves of various sizes. A compression spring 3024 is connected between the second mounting bracket 302 and the telescopic plate 3022, which can push the telescopic plate 3022 outward to apply a certain pressure to the side wall of the mounting groove or mounting hole of the extensometer 4, thereby improving the stability of the extensometer 4.

[0037] like Figure 1 , Figure 2As shown, an adjustment elongated hole 3011 is cut along the length direction on the side surface of the first mounting bracket 301. The first mounting bracket 301 is tunably connected to the moving part of the vertical moving mechanism through the adjustment elongated hole 3011.

[0038] like Figure 1 , Figure 2 , Figure 3 As shown, the top surface and outer side surface of the telescopic plate 3022 are provided with an inlet slope that facilitates the snapping groove of the telescopic plate 3022 and the second mounting bracket 302 into the extensometer 4.

[0039] In this invention, by introducing the inclined surface, the telescopic plate 3022 can be introduced into the snap-fit ​​groove of the extensometer. Then, the compression spring 3024 pushes the telescopic plate 3022 against the outer side of the second mounting bracket 302, thereby firmly fixing the extensometer onto the second mounting bracket 302.

[0040] like Figure 1 As shown, the vertical moving mechanism includes a support frame 201 mounted above the base 1. A vertical screw 202 and a guide post 203 are vertically mounted inside the support frame 201. The vertical screw 202 and the support frame 201 are rotatably mounted, and a drive motor 204 is connected to the top. The guide post 203 is fixedly connected to the support frame 201. It also includes a sliding plate 205, which is mounted on the guide post 203 and screwed to the vertical screw 202. A horizontal mounting bracket is mounted on one side of the sliding plate 205.

[0041] In this invention, the vertical lead screw 202 can be driven to rotate by the drive motor 204. Since the vertical lead screw 202 is screwed to the sliding plate 205, the sliding plate 205 can move up or down along the guide post 203 until the center height of the extensometer 4 meets the experimental requirements and then stops moving. The extensometer 4 is used to clamp the sample.

[0042] In this embodiment, the first sensor is used to measure the height of the upper cutting edge of the extensometer 4, denoted as h1; the second sensor is used to measure the height of the lower cutting edge of the extensometer 4, denoted as h2; and the third sensor is installed on the bottom surface of the horizontal mounting bracket to measure the height of the horizontal mounting bracket, denoted as h3. The calculation module is used to receive data from the first, second, and third sensors, calculate the number of rotations of the output shaft of the drive motor 204, and send it to the controller. The number of rotations n of the output shaft of the drive motor 204 satisfies the following formula: n = [(h1 + h2) / 2 - (h3 + h4)] / P, where h4 is the distance between the symmetrical horizontal plane of the upper and lower cutting edges of the extensometer 4 and the bottom surface of the horizontal mounting bracket, and P is the pitch of the vertical lead screw 202. The controller is used to control the rotation of the drive motor 204 based on the above calculation results, thereby moving the extensometer up / down. A positive value of n causes the extensometer 4 to move upward.

[0043] In this invention, when the length of the sample changes, the clamping points of the sample held by the upper and lower blades of the extensometer 4 will shift by a certain amount. If the height of the extensometer 4 is fixed at this time, the clamping direction of the upper and lower blades of the extensometer 4 on the sample will deflect, causing the upper and lower blades of the extensometer 4 to be unable to clamp the sample perpendicularly, resulting in test failure. If the extensometer 4 is freely suspended on the sample, the weight of the extensometer 4 will have a significant impact on the sample test. At this time, a vertical lead screw is used and the drive motor 204 is precisely controlled to rotate according to the calculation results, thereby controlling the up / down movement of the sliding plate 205. Therefore, the blades of the extensometer 4 are always perpendicular to the direction of fiber force, making the test results more accurate.

[0044] like Figure 1 As shown, it also includes a locking nut 5, one end of which passes through the sliding plate 205 and the horizontal mounting bracket from one side, and is then fixed by a locking washer on the other side.

[0045] In this embodiment, the height of the vertical lead screw 202 is 300mm.

[0046] In this embodiment, the extensometer 4 is model number 3542-050M-050-ST.

[0047] It should be noted that the appendix Figure 1 The extensometer in the example is only one applicable model. This model has a snap-fit ​​groove at the tail, which can be used with a horizontal mounting bracket to fix the extensometer to the horizontal mounting bracket. For other extensometers without a fixed structure at the tail, the extensometer can be fixed to the horizontal mounting bracket by screwing, gluing or other methods.

[0048] Using the attached Figure 1 When using an extensometer of the specified model, place the sample vertically in the middle of the extensometer blade (the right vertical plane of the upper and lower blades in the figure). Secure the sample to the extensometer blade with a rubber band, and then use the four protrusions at the front and back of the extensometer to fix the rubber band in place. For other extensometer models, please refer to the extensometer's instruction manual.

[0049] In this embodiment, the distance between the inner side of the second mounting bracket 302 and the outer side of the telescopic plate 3022 is 10-30mm.

[0050] In this embodiment, the first sensor, the second sensor, and the third sensor are all height sensors or distance sensors.

[0051] The embodiments of this utility model include the following steps:

[0052] 1) Place the extensometer 4 on the second mounting bracket 302. Slide the second mounting bracket 302 and the telescopic plate 3022 into the groove of the extensometer 4 by the chamfer between the top surface and the outer side of the telescopic plate 3022. At this time, the compression spring 3024 will push the telescopic plate 3022 outward away from the second mounting bracket 302. The groove width of the extensometer 4 can be adaptively adjusted to a certain extent to suit extensometers 4 with different groove widths. Due to the outward pushing force of the compression spring 3024, the extensometer 4 can be fixed on the second mounting bracket 302 by friction, preventing the extensometer 4 from falling off due to sudden changes in force after the test.

[0053] 2) Manually adjust the vertical screw 202 to position the extensometer 4 at a suitable height; control the relative position of the adjusting elongated hole 3011 and the sliding plate 205 by tightening the locking nut 4, so that the extensometer 4 is close to the carbon fiber multifilament sample to be tested. Use the upper and lower blades of the extensometer 4 to clamp the carbon fiber multifilament sample respectively. Since the extensometer 4 is mainly supported by the second mounting bracket 302, it can avoid the extensometer 4 from hanging on the carbon fiber multifilament sample, which would affect the test results.

[0054] 3) The tensile test begins. During the tensile process, the carbon fiber multifilament sample undergoes longitudinal stretching, which in turn causes longitudinal displacement of the sample clamping points held by the upper and lower blades of the extensometer 4. This causes a shift in the clamping direction of the upper and lower blades of the extensometer 4, affecting the test results. At this time, the height data of the upper blade, lower blade, and bottom of the extensometer 4 are obtained by the first, second, and third sensors, respectively. When the sample clamping points held by the upper and lower blades of the extensometer 4 undergo longitudinal displacement, the calculation module calculates... The difference between the center of the extensometer and the midpoint height between the upper and lower blades of the extensometer 4 is calculated, and the direction and number of rotations of the vertical screw 202 should be obtained based on this difference. The controller controls the drive motor 204 to rotate the vertical screw 202 according to the data, which drives the sliding plate 205 to move up and down along the guide post 203, so that the extensometer 4 is always at the midpoint height between the upper and lower blades, ensuring that the upper and lower blades of the extensometer 4 are always perpendicularly clamped to the carbon fiber multifilament sample, making the test results more accurate.

[0055] 4) After the tensile test is completed, the carbon fiber multifilament sample breaks. Under the thrust of the compression spring 3024, the extensometer 4 is fixed on the second mounting bracket 302 to prevent the extensometer 4 from falling to the ground and causing damage.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A fixture for testing fiber tensile modulus, characterized in that: Includes a base (1), on which a vertical moving mechanism is provided, and a horizontal mounting frame is installed on the moving part of the vertical moving mechanism, and the extensometer (4) is fixed to the horizontal mounting frame; The horizontal mounting frame includes a first mounting frame (301) that is slidably connected to the moving part of the vertical moving mechanism. One end of the first mounting frame (301) extends horizontally in the vertical direction to a second mounting frame (302). The extensometer (4) is slidably mounted on the second mounting frame (302). The second mounting bracket (302) has multiple insertion slots (3021) with a wider outer surface and a narrower inner surface on its top and bottom surfaces. It also includes a telescopic plate (3022) installed on the outside of the second mounting bracket (302). Multiple insertion rods (3023) that match the insertion slots (3021) are fixedly connected to the top and bottom of the telescopic plate (3022). Each insertion rod (3023) is slidably inserted into each insertion slot (3021). It also includes a compression spring (3024). The two ends of the compression spring (3024) are fixedly connected to the outer side of the second mounting bracket (302) and the inner side of the telescopic plate (3022) respectively, for pushing the telescopic plate (3022) outward.

2. The fiber tensile modulus testing fixture according to claim 1, characterized in that: The extensometer (4) has a first sensor and a second sensor for measuring height detachably installed on one side of the upper and lower blades, respectively. A third sensor for measuring the height of the horizontal mounting frame is also installed on the bottom surface of the horizontal mounting frame.

3. The fiber tensile modulus testing fixture according to claim 2, characterized in that: It also includes a computing module and a controller, a first sensor, a second sensor, a third sensor and a computing module electrically connected, a computing module and a controller electrically connected, and a vertical moving mechanism and a controller electrically connected.

4. The fiber tensile modulus testing fixture according to claim 3, characterized in that: The vertical moving mechanism includes a support frame (201) installed above the base (1), a vertical screw (202) and a guide post (203) are vertically installed inside the support frame (201), the vertical screw (202) and the support frame (201) are rotatably installed, and a drive motor (204) is connected to the top, and the guide post (203) is fixedly connected to the support frame (201); it also includes a sliding plate (205), the sliding plate (205) is mounted on the guide post (203) and screwed to the vertical screw (202), and a horizontal mounting bracket is installed on one side of the sliding plate (205); wherein, the drive motor (204) is electrically connected to the controller.

5. The fiber tensile modulus testing fixture according to claim 4, characterized in that: The first mounting bracket (301) has an adjustment elongated hole (3011) cut along the length direction on its side surface. The first mounting bracket (301) is adjustablely connected to the sliding plate (205) through the adjustment elongated hole (3011).

6. The fiber tensile modulus testing fixture according to claim 5, characterized in that: The top surface and outer side surface of the telescopic plate (3022) are provided with an inlet slope for easy insertion of the telescopic plate (3022) and the second mounting bracket (302) into the extensometer (4).

7. The fiber tensile modulus testing fixture according to claim 6, characterized in that: It also includes a locking nut (5), one end of which passes through the sliding plate (205) and the adjusting elongated hole (3011) from one side and is then fixed by a locking washer screwed to the other side of the first mounting bracket (301).

8. The fiber tensile modulus testing fixture according to claim 7, characterized in that: The height of the vertical lead screw (202) is 300mm.

9. The fiber tensile modulus testing fixture according to claim 5, characterized in that: The distance between the inner side of the second mounting bracket (302) and the outer side of the telescopic plate (3022) is 10-30mm.

10. The fiber tensile modulus testing fixture according to claim 1, characterized in that: The first, second, and third sensors are all height or distance sensors.

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