CN115290411A - Tool and method for preparing carbon fiber multifilament tensile sample - Google Patents

Abstract

The invention provides a tool and a method for preparing a carbon fiber multifilament tensile sample, which comprises the following steps: support, dead lever, gag lever post, pulley, spring balance, frame and fixing bolt, the frame passes through the dead lever and installs on the support, be provided with the C type on the dead lever and press from both sides, the gag lever post includes first gag lever post and second gag lever post, be provided with the pulley on the gag lever post, the second gag lever post sets up the lower extreme at the frame, the upper portion of frame is provided with the spacing groove, peg graft at the spacing inslot at the both ends of first gag lever post, be provided with the locating hole on the frame of spacing groove upper end, fixing bolt installs in the locating hole, first gag lever post is connected to the one end of spring balance, and fixing bolt is connected to the other end, and preparation carbon fiber multifilament tensile sample's frock and method in this application can obviously improve carbon fiber multifilament tensile sample's quality and test data's accuracy, reduces test data's discreteness.

Description

Tool and method for preparing carbon fiber multifilament tensile sample

Technical Field

The invention relates to the technical field of composite material detection, in particular to a tool and a method for preparing a carbon fiber multifilament tensile sample.

Background

The carbon fiber material has wide application fields, particularly benefits from the high strength characteristic, and can be suitable for manufacturing various special products, such as composite gas cylinders which need to bear higher pressure. In order to ensure the performance of the product, various tests are generally required to determine that the performance of the carbon fiber is in accordance with the requirements.

The tensile property of the multifilament is one of the important indexes for inspecting the performance of the carbon fiber yarn bundle. The mechanical property of the carbon fiber multifilament can be used for finite element analysis and evaluation of the performance of the carbon fiber body, and in order to truly simulate the stress condition of the carbon fiber, a tensile property test of the carbon fiber multifilament is usually selected. The key point of the multifilament tensile property test lies in the manufacture of multifilament samples, the sample preparation mode is divided into manual and mechanical, the mechanical sample preparation procedure is complex, the processing requirement difficulty of sample preparation workpieces is high, the assembly and matching precision requirement is high, the large-scale popularization is not suitable, and the manual sample preparation is still a technology generally adopted in the current industry due to the convenient process. The key points for manufacturing the sample are glue content control, tension control and straight yarn shape, and the tension control comprises the following steps: the uniformity degree of the internal tension of the yarn bundle, the uniformity of the tension of different samples and the magnitude of the tension. The ubiquitous appearance of making in the trade is that the requirement of gel content is lower, easy control, but tension control, sample width only rely on manual regulation of people, and different people operate to and there is great difference in the different splines of same person operation, and this kind of spline easily takes place abnormal destruction in the testing process, has seriously influenced the discreteness and the accuracy of test result. At present, no proper tool and sample preparation method exist.

The invention discloses a sample preparation method of a carbon fiber tensile sample, which is disclosed by the invention with the publication number of CN113884368A and the name of 'a carbon fiber tensile sample preparation method, a preparation frame and a sample', and mainly comprises the steps of twisting each strand of carbon fiber into a round rod shape, fixing the round rod shape, the preparation frame and the sample, then adjusting a sliding plate to ensure that each strand of carbon fiber has the same tension, then uniformly coating epoxy resin on the carbon fiber, standing to ensure that the epoxy resin is soaked in the carbon fiber, wiping off redundant epoxy resin glue drops to obtain a first semi-finished sample, carrying out a first curing process on the first semi-finished sample, cutting off carbon fiber with a proper length to obtain a second semi-finished sample, fixedly pasting reinforcing plates on two ends of the second semi-finished sample by using quick-drying glue to obtain a third semi-finished sample, immersing two ends of the third semi-finished sample fixedly pasted with the reinforcing plates in the epoxy resin, taking out, controlling to dry until the epoxy resin does not drop again, wiping off the redundant epoxy resin drops, and obtaining a finished sample through a second curing process; although the carbon fiber sample can be manufactured by the method, a plurality of defects still exist, after the carbon fiber is wound on the fixed plate and the sliding plate, the carbon fiber is difficult to stretch only by virtue of the compression spring, on one hand, the friction force of the carbon fiber is large in a dry yarn state, the sliding plate is difficult to transmit the tension, the sliding plate can only move relative to the frame, the tension is difficult to be uniform and equal, on the other hand, the carbon fiber cannot be effectively fixed, and the uniformity of the length of a single fiber in the carbon fiber yarn cannot be ensured.

Disclosure of Invention

In view of the above, the invention aims to provide a tool and a method for preparing a carbon fiber multifilament tensile sample so as to solve the problems that in the prior art, when a carbon fiber sample is prepared, the tensile force is uneven, the straightness is poor, so that a sample strip is easy to be abnormally damaged in the testing process, and the discreteness and the accuracy of a testing result are seriously influenced.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a tool for preparing a carbon fiber multifilament tensile sample comprises: support, dead lever, gag lever post, pulley, spring balance, frame and fixing bolt, the frame passes through the dead lever to be installed on the support, be provided with the C type on the dead lever and press from both sides, the gag lever post includes first gag lever post and second gag lever post, be provided with the pulley on the gag lever post, the second gag lever post sets up the lower extreme at the frame, the upper portion of frame is provided with the spacing groove, peg graft at the spacing inslot in the both ends of first gag lever post, be provided with the locating hole on the frame of spacing groove upper end, fixing bolt installs in the locating hole, first gag lever post is connected to the one end of spring balance, and fixing bolt is connected to the other end.

Preparation carbon fiber multifilament tensile sample's frock in this application, fix carbon fiber yarn through the C type clamping, the centre gripping is firm and convenient to use, carbon fiber yarn winding is on the pulley, the groove width of pulley can be adjusted according to actual demand, conveniently make the sample of different specifications, and rotation and the horizontal slip through the pulley can effectively avoid the problem of sample internal stress concentration, make the sample atress even and straight, the spring balance can make the tension that the sample received unanimous and steady, fixing bolt can adjust the position of spring balance, the pulling force that convenient adjustment sample received, the frame can rotate on the support when winding carbon fiber yarn, make the even winding of carbon fiber yarn on the pulley, this kind of structure system appearance high efficiency is stable and convenient operation.

Further, the C-clamp includes a first C-clamp and a second C-clamp.

The clamping end of the C-shaped clamp is a flat surface, when carbon fiber yarns are clamped, the flat surface can ensure that the tensioning degree of each yarn is the same, the yarns are evenly stressed, the first C-shaped clamp is used for fixing the starting end of the yarns when the carbon fiber yarns are wound, the second C-shaped clamp is used for fixing the tail end of the yarns after the yarns are wound, the C-shaped clamp can freely slide on the fixing rod, and the structure is firm in fixing and convenient to use.

Furthermore, the spacing groove includes first spacing groove and second spacing groove, first spacing groove sets up the left side of frame, the second spacing groove sets up the right side of frame, first spacing groove and second spacing groove symmetry are just parallel.

The first limiting groove is parallel to the second limiting groove, so that the first limiting rod can be kept parallel to the second limiting rod, and the carbon fiber yarns are straight and are uniformly stressed.

Furthermore, the left end of the first limiting rod is inserted into the first limiting groove, the right end of the first limiting rod is inserted into the second limiting groove, and the first limiting rod can move in the limiting groove.

The structure facilitates the installation and the disassembly of the first limiting rod and is also beneficial to the movement of the first limiting rod in the limiting groove.

Furthermore, the number of the pulleys arranged on the first limiting rod and the second limiting rod is the same, and the pulleys on the first limiting rod and the second limiting rod are in one-to-one correspondence in the vertical direction.

The pulleys arranged on the first limiting rod and the second limiting rod correspond to each other one by one, and the structure is convenient for keeping the yarns straight when the carbon fiber yarns are wound and is also convenient for operation.

Furthermore, the positioning holes include a first positioning hole and a second positioning hole, the first positioning hole is disposed on the left side of the frame, the second positioning hole is disposed on the right side of the frame, and the first positioning hole and the second positioning hole are symmetrical and parallel.

The structure facilitates installation of the fixing bolt, and when the spring scale is connected to the fixing bolt and the first limiting rod, two ends of the first limiting rod can be parallel to each other and stressed evenly.

Further, the fixing bolt comprises a first fixing bolt and a second fixing bolt, the first fixing bolt is installed in the first positioning hole, and the second fixing bolt is installed in the second positioning hole.

The front end and the rear end of the first fixing bolt are respectively provided with a nut, the nut at the front end of the first fixing bolt is abutted against the left end face of the first positioning hole, the nut at the rear end of the first fixing bolt is abutted against the right end face of the first positioning hole, the first fixing bolt is fixed in the first positioning hole, and the second fixing bolt is fixed in the first positioning hole in the same way as the first fixing bolt.

Further, the spring scale comprises a first spring scale and a second spring scale, the upper end of the first spring scale is connected with the first fixing bolt, the lower end of the first spring scale is connected with one end of the first limiting rod, the upper end of the second spring scale is connected with the second fixing bolt, and the lower end of the second spring scale is connected with the other end of the first limiting rod.

Through the pulling force of adjusting first spring balance and second spring balance, make the both ends atress of first gag lever post the same to ensure that the sample is straight and the atress is even.

The invention also provides a method for preparing a carbon fiber multifilament tensile sample based on the tool, which comprises the following steps:

s1, selecting pulleys with corresponding quantity and specifications according to the requirements of a sample, installing the corresponding pulleys on a limiting rod, and then installing the limiting rod on a frame;

s2, vertically placing the frame, and adjusting the distance between the first limiting rod and the second limiting rod according to needs;

s3, after the tool is prepared, winding one end of the carbon fiber yarn on a fixed rod in the middle of the frame, and then fixing the carbon fiber yarn by using a first C-shaped clamp;

s4, winding the fixed carbon fiber yarns in pulley grooves of the first limiting rod and the second limiting rod in sequence, and cutting the carbon fiber yarns after winding is finished;

s5, winding the carbon fiber yarns cut off in the step S4 on a fixing rod, and then fixing the carbon fiber yarns by using a second C-shaped clamp 212;

s6, infiltrating the carbon fiber yarns by using the mixed epoxy resin;

s7, after the carbon fiber yarns are soaked by epoxy resin, hooking one end of a first limiting rod by using a first spring scale, hooking the other end of a second limiting rod by using a second spring scale, and stretching the first spring scale and the second spring scale to enable the tension of the first spring scale and the tension of the second spring scale to reach a preset value;

s8, fixing the spring scale in a positioning hole of the frame by using a fixing bolt, and adjusting the position of the fixing bolt to enable the tension of the spring scale to reach a preset value;

s9, controlling the size of a test area of the sample and the size of the reinforcing sheet according to the standard GB/T3362-2017, respectively bonding and clamping two ends of the sample by the reinforcing sheet, then curing, and after the sample is cured, cutting the reinforcing sheet according to the standard GB/T3362-2017 to obtain the carbon fiber multifilament tensile sample.

In step S2, the size of the sample is changed by adjusting the distance between the first stopper rod and the second stopper rod.

In step S4, the carbon fiber yarn is wound around the first set of pulleys corresponding to the first and second limiting rods, and after the yarn covers all of the grooves of the first set of pulleys, the second set of pulleys are wound, and the carbon fiber yarn is cut off after the corresponding pulleys on the first and second limiting rods are wound.

In step S7, after the carbon fiber yarn is soaked by the epoxy resin, the yarn is stretched by using a spring scale, and the yarn is automatically adjusted to be aligned by sliding under the lubrication of the resin, so that the sample can be conveniently manufactured.

In step S9, the reinforcing sheet may be kraft paper or a glass fiber reinforced plastic molding plate, and then the reinforcing sheet is bonded to both ends of the sample by using an epoxy structural adhesive.

Furthermore, the distance D between the first limiting rod and the second limiting rod is more than or equal to 350mm.

Compared with the prior art, the tool and the method for preparing the carbon fiber multifilament tensile sample have the following advantages:

firstly, the tension of the carbon fiber yarns can be effectively controlled, so that the tension of each sample is uniform and consistent, and the size of each sample is controllable; secondly, the test sample can be flat and straight, the width is uniform and consistent, and the test sample is prevented from being distorted and deformed; thirdly, the tension on the sample can be accurately controlled through a spring balance, so that the optimal multifilament drawing sample preparation tension can be conveniently researched; fourthly, compared with the conventional method, the tensile strength and the discreteness of the sample are both greatly improved; by adopting the preparation tool and the preparation method, the quality of the carbon fiber multifilament tensile sample and the accuracy of test data can be obviously improved, and the discreteness of the test data is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a first view angle of a tool for preparing a carbon fiber multifilament tensile sample according to the present invention;

fig. 2 is a structural schematic diagram of a second view angle of the carbon fiber multifilament tensile sample preparation tool in the invention.

Description of reference numerals:

1-support, 2-fixing rod, 21-C type clamp, 211-first C type clamp, 212-second C type clamp, 3-limiting rod, 31-first limiting rod, 310-limiting groove, 311-first limiting groove, 312-second limiting groove, 32-second limiting rod, 4-pulley, 5-spring scale, 51-first spring scale, 52-second spring scale, 6-frame, 7-fixing bolt, 71-first fixing bolt, 72-second fixing bolt, 8-positioning hole, 81-first positioning hole and 82-second positioning hole.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Example 1

As shown in fig. 1-2, a tool for preparing a carbon fiber multifilament tensile specimen includes: support 1, dead lever 2, gag lever post 3, pulley 4, spring balance 5, frame 6 and fixing bolt 7, frame 6 passes through dead lever 2 to be installed on support 1, be provided with C type clamp 21 on the dead lever 2, gag lever post 3 includes first gag lever post 31 and second gag lever post 32, be provided with pulley 4 on the gag lever post 3, second gag lever post 32 sets up the lower extreme at frame 6, the upper portion of frame 6 is provided with spacing groove 310, peg graft in spacing groove 310 at first gag lever post 31's both ends, be provided with locating hole 8 on the frame 6 of spacing groove 310 upper end, fixing bolt 7 installs in the locating hole 8, first gag lever post 31 is connected to the one end of spring balance 5, and fixing bolt 7 is connected to the other end.

Preparation carbon fiber multifilament tensile sample's in this application frock, press from both sides 21 fixed carbon fiber yarn through the C type, the centre gripping is firm and convenient to use, carbon fiber yarn twines on pulley 4, pulley 4's groove width can be adjusted according to the actual demand, conveniently make the sample of different specifications, and can effectively avoid the problem of sample internal stress concentration through pulley 4's rotation and horizontal slip, make the sample atress even and straight, spring scale 5 can make the tension that the sample received unanimous and steady, fixing bolt 7 can adjust spring scale 5's position, conveniently adjust the pulling force that the sample received, frame 6 can rotate on support 1 when winding carbon fiber yarn, make the even winding of carbon fiber yarn on pulley 4, this kind of structure system appearance is high-efficient stable and convenient operation.

As a preferred example of the present invention, the C-clip 21 includes a first C-clip 211 and a second C-clip 212.

Specifically, the exposed core of C type clamp 21 is the platykurtic, and when centre gripping carbon fiber yarn, the platykurtic can guarantee that every yarn tensioning degree is all the same, makes the yarn atress even, and at carbon fiber yarn winding inception, with the initiating terminal of the fixed yarn of first C type clamp 211, after the yarn winding, with the end of the fixed yarn of second C type clamp 212, just C type clamp 21 can freely slide on dead lever 2, and this kind of fixed structure is firm and convenient to use.

As a preferred example of the present invention, the limiting groove 310 includes a first limiting groove 311 and a second limiting groove 312, the first limiting groove 311 is disposed on the left side of the frame 6, the second limiting groove 312 is disposed on the right side of the frame 6, and the first limiting groove 311 and the second limiting groove 312 are symmetrical and parallel.

Specifically, the first limiting groove 311 is parallel to the second limiting groove 312, so that the first limiting rod 31 can be parallel to the second limiting rod 32, and the carbon fiber yarn is straight and stressed uniformly.

Preferably, the stopper groove 310 is a blind groove, and is capable of stopping the first stopper rod 31.

Preferably, the vertical cross section of the limiting groove 310 is rectangular, so that the first limiting rod 311 can move up and down in the limiting groove 310, the distance between the first limiting rod 311 and the second limiting rod 312 is changed, the tension force applied to the carbon fiber yarn is changed, and the carbon fiber yarn is conveniently tensioned in the operation process.

As a preferred example of the present invention, the left end of the first limiting rod 31 is inserted into the first limiting groove 311, the right end of the first limiting rod 31 is inserted into the second limiting groove 312, and the first limiting rod 31 can move in the limiting groove 310.

Specifically, the structure facilitates the mounting and dismounting of the first limiting rod 31, and also facilitates the movement of the first limiting rod 31 in the limiting groove 310.

As a preferred example of the present invention, the pulleys 4 disposed on the first limiting rod 31 and the second limiting rod 32 are the same in number, and the pulleys 4 on the first limiting rod 31 and the second limiting rod 32 are in one-to-one correspondence in the vertical direction.

Specifically, the pulleys 4 arranged on the first limiting rod 31 and the second limiting rod 32 correspond to each other one by one, and the structure is convenient for keeping the yarn straight when the carbon fiber yarn is wound and is also convenient for operation.

As a preferred example of the present invention, the positioning holes 8 include a first positioning hole 81 and a second positioning hole 82, the first positioning hole 81 is disposed on the left side of the frame 6, the second positioning hole 82 is disposed on the right side of the frame 6, and the first positioning hole 81 and the second positioning hole 82 are symmetrical and parallel.

Specifically, this kind of structure is convenient for install fixing bolt 7, and when spring balance 5 connected on fixing bolt 7 and first gag lever post 31, can make the both ends of first gag lever post 31 parallel and the atress even.

Preferably, the positioning hole 8 is a through hole, so that the fixing bolt 7 can be conveniently installed.

Preferably, the vertical section of the positioning hole 8 is rectangular, so that the fixing bolt 7 has a larger adjusting distance, and the tension of the spring scale 5 can be conveniently adjusted.

As a preferred example of the present invention, the fixing bolt 7 includes a first fixing bolt 71 and a second fixing bolt 72, the first fixing bolt 71 is installed in the first positioning hole 81, and the second fixing bolt 72 is installed in the second positioning hole 82.

Specifically, the front end and the rear end of the first fixing bolt 71 are respectively provided with a nut, the nut at the front end abuts against the left end face of the first positioning hole 81, the nut at the rear end abuts against the right end of the first positioning hole 81, so that the first fixing bolt 71 is fixed in the first positioning hole 81, and the second fixing bolt 72 is fixed in the same manner as the first fixing bolt 71.

As a preferred example of the present invention, the spring balance 5 includes a first spring balance 51 and a second spring balance 52, wherein the first spring balance 51 has an upper end connected to the first fixing bolt 71 and a lower end connected to one end of the first limiting rod 31, the second spring balance 52 has an upper end connected to the second fixing bolt 72 and a lower end connected to the other end of the first limiting rod 31.

Specifically, the tension of the first spring balance 51 and the tension of the second spring balance 52 are adjusted to enable the two ends of the first limiting rod 31 to be stressed equally, so that the sample is ensured to be flat and stressed evenly.

Preferably, a mechanical spring scale or a digital display type spring scale may be used.

Example 2

As shown in fig. 1-2, a method of making a carbon fiber multifilament tensile specimen comprises:

s1, selecting pulleys 4 with corresponding quantity and specifications according to sample requirements, installing the corresponding pulleys 4 on a limiting rod 3, and then installing the limiting rod 3 on a frame 6;

s2, vertically placing the frame 6, and adjusting the distance between the first limiting rod 31 and the second limiting rod 32 according to needs;

s3, after the tool is prepared, winding one end of the carbon fiber yarn on the fixing rod 2 in the middle of the frame 6, and then fixing the carbon fiber yarn by using a first C-shaped clamp 211;

s4, winding the fixed carbon fiber yarns in grooves of pulleys 4 of the first limiting rod 31 and the second limiting rod 32 in sequence, and cutting off the carbon fiber yarns after winding is finished;

s5, winding the carbon fiber yarns cut off in the step S4 on a fixing rod 2, and then fixing the carbon fiber yarns by using a second C-shaped clamp 212;

s6, infiltrating the carbon fiber yarns by using the mixed epoxy resin;

s7, after the carbon fiber yarns are soaked by epoxy resin, hooking one end of the first limiting rod 31 by using a first spring scale 51, hooking the other end of the second limiting rod 32 by using a second spring scale 52, and then stretching the first spring scale 51 and the second spring scale 52 to enable the tension of the first spring scale 51 and the tension of the second spring scale 52 to reach a preset value;

s8, fixing the spring scale 5 in a positioning hole 8 of the frame 6 by using a fixing bolt 7, and adjusting the position of the fixing bolt 7 to enable the tension of the spring scale 5 to reach a preset value;

s9, controlling the size of a test area of the sample and the size of the reinforcing sheet according to the standard GB/T3362-2017, respectively bonding and clamping two ends of the sample by the reinforcing sheet, curing, and cutting the reinforcing sheet according to the standard GB/T3362-2017 after the sample is cured to obtain the carbon fiber multifilament tensile sample.

In step S2, the size of the sample is changed by adjusting the distance between the first stopper rod 31 and the second stopper rod 32, but the distance D between the first stopper rod 31 and the second stopper rod 32 is not less than 350mm.

In step S4, the carbon fiber yarn is wound around the first set of pulleys 4 corresponding to the first limiting rod 31 and the second limiting rod 32, and then wound around the second set of pulleys 4 after the yarn covers all the grooves of the first set of pulleys 4, and then the carbon fiber yarn is cut off after the corresponding pulleys 4 on the first limiting rod 31 and the second limiting rod 32 are wound.

In step S7, after the carbon fiber yarn is soaked by the epoxy resin, the yarn is stretched by the spring scale 5, and the yarn is automatically adjusted to be aligned by sliding under the lubrication of the resin, so that the sample is conveniently manufactured.

In step S9, the reinforcing sheet may be kraft paper or a glass fiber reinforced plastic molding plate, and then the reinforcing sheet is bonded to both ends of the sample by using an epoxy structural adhesive.

Preferably, a strip-shaped glass fiber reinforced plastic molding board with the width of 50mm is selected as a reinforcing sheet, the size of a test area of the sample is controlled according to the requirement of GB/T3362-2017, two ends of the sample are respectively bonded and clamped by the reinforcing sheet, the adjacent samples are mutually parallel and have equal gaps, then the samples are cured, the reinforcing sheet can be placed in a curing oven for curing, and after the curing is finished, the reinforcing sheet is cut according to the size specified by GB/T3362-2017, so that the carbon fiber multifilament tensile sample is obtained.

The test of the renatured eagle T700-24k grade carbon fiber was carried out using the above carbon fiber multifilament tensile sample preparation method, and the results are shown in Table 1:

TABLE 1

In summary, the method for preparing the carbon fiber multifilament tensile sample has the advantages that firstly, the tension of the carbon fiber yarns can be effectively controlled, so that the tension of each sample is uniform and consistent, and the size of each sample is controllable; secondly, the test sample can be straight and uniform in width, and the test sample is prevented from being distorted and deformed; thirdly, the tension applied to the sample can be accurately controlled through the spring balance 5, so that the optimal multifilament stretching sample preparation tension can be conveniently researched; fourthly, compared with the conventional method, the tensile strength and the discreteness of the sample are both greatly improved; by adopting the preparation tool and the preparation method, the quality of the carbon fiber multifilament tensile sample and the accuracy of test data can be obviously improved, and the discreteness of the test data is reduced.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected by one skilled in the art without departing from the spirit and scope of the invention, as defined in the appended claims.

Claims (10)

1. The utility model provides a frock of preparation carbon fiber multifilament tensile sample which characterized in that includes: support (1), dead lever (2), gag lever post (3), pulley (4), spring balance (5), frame (6) and fixing bolt (7), install on support (1) through dead lever (2) frame (6), be provided with the C type on dead lever (2) and press from both sides, gag lever post (3) are including first gag lever post (31) and second gag lever post (32), be provided with pulley (4) on gag lever post (3), second gag lever post (32) set up the lower extreme at frame (6), the upper portion of frame (6) is provided with spacing groove (310), peg graft in spacing groove (310) in the both ends of first gag lever post (31), be provided with locating hole (8) on spacing groove (310) frame (6), fixing bolt (7) are installed in locating hole (8), first gag lever post (31) is connected to the one end of spring balance (5), and fixing bolt (7) are connected to the other end.

2. The tooling of claim 1, wherein the C-clamp (21) comprises a first C-clamp (211) and a second C-clamp (212).

3. The tooling according to claim 1, wherein the limiting grooves (310) comprise a first limiting groove (311) and a second limiting groove (312), the first limiting groove (311) is arranged on the left side of the frame (6), the second limiting groove (312) is arranged on the right side of the frame (6), and the first limiting groove (311) and the second limiting groove (312) are symmetrical and parallel.

4. The tooling of claim 3, wherein the left end of the first limiting rod (31) is inserted into the first limiting groove (311), the right end of the first limiting rod (31) is inserted into the second limiting groove (312), and the first limiting rod (31) can move in the limiting groove (310).

5. The tooling according to claim 1, characterized in that the pulleys (4) arranged on the first limiting rod (31) and the second limiting rod (32) are the same in number, and the pulleys (4) on the first limiting rod (31) and the second limiting rod (32) are in one-to-one correspondence in the vertical direction.

6. The tooling according to claim 1, wherein the positioning holes (8) comprise a first positioning hole (81) and a second positioning hole (82), the first positioning hole (81) is arranged on the left side of the frame (6), the second positioning hole (82) is arranged on the right side of the frame (6), and the first positioning hole (81) and the second positioning hole (82) are symmetrical and parallel.

7. The tooling according to claim 6, wherein the fixing bolt (7) comprises a first fixing bolt (71) and a second fixing bolt (72), the first fixing bolt (71) is mounted in the first positioning hole (81), and the second fixing bolt (72) is mounted in the second positioning hole (82).

8. The tool according to claim 7, characterized in that the spring scale (5) comprises a first spring scale (51) and a second spring scale (52), the upper end of the first spring scale (51) is connected with the first fixing bolt (71), the lower end of the first spring scale is connected with one end of the first limiting rod (31), the upper end of the second spring scale (52) is connected with the second fixing bolt (72), and the lower end of the second spring scale is connected with the other end of the first limiting rod (31).

9. A method for preparing a carbon fiber multifilament tensile specimen based on the tooling of claim 1, characterized by comprising:

s1, selecting pulleys (4) with corresponding quantity and specifications according to sample requirements, installing the corresponding pulleys (4) on a limiting rod (3), and then installing the limiting rod (3) on a frame (6);

s2, vertically placing the frame (6), and adjusting the distance between the first limiting rod (31) and the second limiting rod (32) according to needs;

s3, after the tool is prepared, winding one end of the carbon fiber yarn on a fixing rod (2) in the middle of a frame (6), and then fixing the carbon fiber yarn by using a first C-shaped clamp (211);

s4, winding the fixed carbon fiber yarns in grooves of the pulleys (4) of the first limiting rod (31) and the second limiting rod (32) in sequence, and cutting off the carbon fiber yarns after winding is finished;

s5, winding the carbon fiber yarns cut off in the step S4 on a fixing rod (2), and then fixing the carbon fiber yarns by using a second C-shaped clamp (212);

s6, infiltrating the carbon fiber yarns by using the mixed epoxy resin;

s7, after the carbon fiber yarns are soaked by epoxy resin, hooking one end of a first limiting rod (31) by using a first spring scale (51), hooking the other end of a second limiting rod (32) by using a second spring scale (52), and stretching the first spring scale (51) and the second spring scale (52) to enable the tension of the first spring scale (51) and the tension of the second spring scale (52) to reach a preset value;

s8, fixing the spring scale (5) in a positioning hole (8) of the frame (6) by using a fixing bolt (7), and adjusting the position of the fixing bolt (7) to enable the tension of the spring scale (5) to reach a preset value;

s9, controlling the size of a test area of the sample and the size of the reinforcing sheet according to the standard GB/T3362-2017, respectively bonding and clamping two ends of the sample by the reinforcing sheet, then curing, and after the sample is cured, cutting the reinforcing sheet according to the standard GB/T3362-2017 to obtain the carbon fiber multifilament tensile sample.

10. The method for preparing the carbon fiber multifilament tensile specimen according to claim 9, wherein the distance D between the first stopper rod (31) and the second stopper rod (32) is not less than 350mm.

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