Needling preform and needling equipment

Abstract

The invention relates to a needling preform and needling equipment, the needling preform comprises a plurality of fiber web tire layers, and the needling preform has the following characteristics: each fiber web tire layer is provided with a plurality of lock catch structures formed by winding and knotting two strands of carbon fiber wires; the lock catch structure and the vertical parts of the two strands of carbon fiber wires connected to the two ends of the lock catch structure form a vertical fiber bundle; in each fiber web tire layer, the fracture rate of the vertical fiber bundles is lower than 20%. According to the needled preform, the fracture rate of the vertical fiber bundles is lower than 20%, the proportion of the fractured vertical fiber bundles is small, the proportion of the unfractured vertical fiber bundles is larger, the interlayer shearing mechanical property of the fiber web tire layer is improved, and the interlayer shearing mechanical property of the fiber web tire layer can be improved by 51-62%.

Description

Technical Field

[0001] The invention belongs to the technical field of batteries and relates to a needle-punched preform and a needle-punched device. Background Art

[0002] Carbon fiber reinforced resin-based composites (CFRP) are widely used in aerospace and other military and civilian fields. Carbon fiber reinforced resin-based composites have the advantages of high specific strength, high specific modulus, corrosion resistance, fatigue resistance and small thermal expansion coefficient. As a reinforcement of carbon fiber reinforced resin-based composites, needle-punched preforms have the advantages of high pore structure and distribution uniformity, strong designability, and easy densification. The structure and molding process parameters of the needle-punched preform directly determine the performance of the needle-punched preform and its reinforced carbon fiber reinforced resin-based composites.

[0003] The current mainstream molding process for needle-punched preforms is to use a carbon fiber mesh layer (formed by stacking a fiber cloth and a fiber mesh) and a carbon fiber thread as the raw materials for needle-punching. A barbed needle is used to needle-punch the fiber mesh layer. After multiple layers of needling, a needle-punched preform with a certain strength is formed. The needling allows the preform to form short vertical fiber bundles by pulling the fibers in the direction of the fiber layer laying through the barbs of the needle. The proportion of broken vertical fiber bundles is relatively large, and the interlayer shear mechanical properties of the fiber mesh layer are poor. Summary of the invention

[0004] The technical problem to be solved by the present invention is: to provide a needle-punched preform and a needle-punching device for the problem that the needle-punched preform obtained by the current mainstream needle-punched preform molding process has a large proportion of broken vertical fiber bundles and poor interlayer shear mechanical properties of the fiber mesh layer.

[0005] In order to solve the above technical problems, on the one hand, an embodiment of the present invention provides a needle-punched preform, wherein the needle-punched preform comprises a multi-layered fiber web layer, and the needle-punched preform has the following characteristics:

[0006] Each fiber web layer has a plurality of locking structures formed by two strands of carbon fiber lines being twisted and knotted, and the locking structures and the vertical parts of the two strands of carbon fiber lines connected at both ends of the locking structures form a vertical fiber bundle;

[0007] In each fiber web layer, the breakage rate of the vertical fiber bundles is less than 20%.

[0008] In each fiber web layer, the vertical fiber bundles are 20-25 bundles / cm 2 .

[0009] Optionally, a plurality of the locking structures are arranged in a rectangular array in the XY plane.

[0010] Optionally, the fiber web layer has a thickness of 1-15 mm.

[0011] Optionally, the fiber web layer is provided with 10-100 layers, the thickness of the needle-punched preform is 10-80 mm, and the density of the needle-punched preform is 0.3-0.8 g / cm 3 .

[0012] The needle-punched preform of the embodiment of the present invention has a plurality of locking structures formed by two strands of carbon fiber wires being twisted and knotted in each fiber mesh layer. The locking structures and the vertical (Z-direction) parts of the two carbon fiber wires connected at both ends of the locking structures constitute a vertical fiber bundle. In each fiber mesh layer, the breakage rate of the vertical fiber bundles is less than 20%, and the proportion of unbroken vertical fiber bundles can be as high as more than 80%, thereby improving the interlayer shear mechanical properties of the fiber mesh layer. The interlayer shear mechanical properties of the fiber mesh layer can be improved by 51-62%.

[0013] On the other hand, an embodiment of the present invention further provides a needling device for preparing the above-mentioned needling preform, the needling device comprising at least one needling unit, the needling unit comprising a frame, a lifting mechanism, a needle, a wire taking mechanism, a first wire rack and a second wire rack, one end of the lifting mechanism is mounted on the top of the frame, the needle is vertically mounted on the bottom of the lifting mechanism, the lifting mechanism is used to drive the needle to move along the Z-axis direction, the first wire rack and the second wire rack are connected to the frame, the first wire rack is used to place a first carbon fiber coil, and the second wire rack is used to place a second carbon fiber coil;

[0014] The thread taking mechanism is rotatably connected to the second thread rack and is located below the needle, and the needle hole on the needle is used to penetrate the free end of the carbon fiber thread of the first carbon fiber coil;

[0015] The wire taking mechanism can rotate between a wire taking position and a knotting position. When the wire taking mechanism rotates to the wire taking position, the carbon fiber wire of the first carbon fiber coil can be taken out. When the wire taking mechanism rotates to the knotting position, the carbon fiber wire of the first carbon fiber coil and the carbon fiber wire of the second carbon fiber coil can be entangled and knotted to form a locking structure. The lifting mechanism can drive the needle to move upward to bring the locking structure into the fiber mesh layer.

[0016] Optionally, a plurality of acupuncture units are provided.

[0017] Optionally, the surface of the needle is smooth, and the needle has a columnar needle rod and a conical needle tip connected to the lower end of the needle rod.

[0018] Optionally, the length of the needle is 50-70 mm, and the diameter of the needle shaft is 2-3 mm;

[0019] The pinhole is a circular hole or an elliptical hole, and the size of the pinhole at the maximum aperture is 1-1.5 mm.

[0020] Optionally, the wire taking mechanism includes a support frame and a C-shaped ring, the support frame is rotatably connected to the second wire frame, the C-shaped ring is connected to the outside of the support frame, the two sides of the notch of the C-shaped ring respectively form a head end and a tail end, and the head end is provided with a wire taking groove for taking out the carbon fiber wire of the first carbon fiber coil;

[0021] It also includes a wire taking driving member for driving the C-shaped ring to rotate.

[0022] Optionally, it also includes:

[0023] A controller is electrically connected to the lifting mechanism and the wire-taking driving component respectively to control the lifting and lowering of the lifting mechanism and the rotation of the wire-taking driving component.

[0024] Optionally, the wire removal groove has a triangular cross-section and its opening faces the notch of the C-shaped ring.

[0025] Optionally, the top angle of the cross section of the wire taking slot is 60-90 degrees;

[0026] The radial width of the C-shaped ring is 2-4 mm.

[0027] Optionally, it also includes:

[0028] A first X-axis moving mechanism, used for driving the lifting mechanism to move along the X-axis direction;

[0029] A first Y-axis moving mechanism, used for driving the lifting mechanism to move along the Y-axis direction;

[0030] A second X-axis moving mechanism, used for driving the second wire rack to move along the X-axis direction;

[0031] The second Y-axis moving mechanism is used to drive the second wire rack to move along the Y-axis direction.

[0032] Optionally, the frame includes a top rail, a bottom rail, a first side plate and a second side plate, the first side plate and the second side plate extend along the Y-axis direction, and the top rail and the bottom rail extend along the X-direction; the upper end of the lifting mechanism is slidably connected to the top rail, and the lower end of the second wire rack is slidably connected to the bottom rail;

[0033] The top guide rail is slidably connected between the top of the first side plate and the top of the second side plate, the first X-axis moving mechanism can drive the lifting mechanism to move along the top guide rail, and the first Y-axis moving mechanism can drive the top guide rail and the lifting mechanism to move along the Y-axis direction;

[0034] The bottom guide rail is slidably connected between the bottom of the first side plate and the bottom of the second side plate, the second X-direction moving mechanism can drive the second wire rack to move along the bottom guide rail, and the second Y-direction moving mechanism can drive the bottom guide rail and the second wire rack to move along the Y-axis direction.

[0035] In the acupuncture device of the embodiment of the present invention, the wire taking mechanism can rotate between the wire taking position and the knotting position. When the wire taking mechanism rotates to the wire taking position, the carbon fiber wire of the first carbon fiber coil can be taken off. When the wire taking mechanism rotates to the knotting position, the carbon fiber wire of the first carbon fiber coil and the carbon fiber wire of the second carbon fiber coil can be intertwined and knotted to form a locking structure. The lifting mechanism can drive the needle to move upward to bring the locking structure into the fiber mesh layer. The acupuncture of a single layer of fiber mesh layer can be completed by acupuncturing the fiber mesh layer multiple times along the XY plane direction. After multiple layers of acupuncture, a needle-punched preform with a certain strength is formed. The needle-punched preform prepared by the acupuncture device has the following characteristics: in each fiber mesh layer, there are multiple locking structures formed by two strands of carbon fiber wires intertwined and knotted; in each fiber mesh layer, the proportion of complete vertical fiber bundles is 80-100%.

[0036] In addition, the needle punching device of the present invention can improve the compactness of the needle punched preform, greatly increase the proportion of radial carbon fibers, and the needle punched preform formed in this way can be well formed. Moreover, each needle punching unit has only one needle, and the needle has no barb structure, is not easy to wear, and is not easy to break during the needle punching process, which can reduce production costs.

[0037] In addition, since the acupuncture device operates with a single needle, the acupuncture device does not need to be too large, can save space, and is easy to place.

[0038] In addition, the formed carbon fibers are continuous, which solves the problems of short and disordered carbon fibers in the existing needle-punched preform molding process and increases the strength of the needle-punched preform. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of an acupuncture device provided by an embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of an acupuncture device provided by another embodiment of the present invention;

[0041] Figure 3 is an enlarged schematic diagram of the lock structure;

[0042] Figure 4 is a schematic diagram of acupuncture effect of an acupuncture device provided by an embodiment of the present invention;

[0043] Figure 5It is a schematic diagram of the needling effect of the forming process of the needling preform in the prior art.

[0044] The reference numerals in the specification are as follows:

[0045] 10. Needle punching unit; 20. First carbon fiber coil; 30. Second carbon fiber coil; 40. Locking structure; 50. Fiber web layer;

[0046] 1. Frame; 11. Top guide rail; 12. Bottom guide rail; 13. First side panel; 131. First guide rail; 132. Third guide rail; 14. Second side panel; 141. Second guide rail; 142. Fourth guide rail; 2. Lifting mechanism; 21. First slider; 3. Needle; 31. Needle hole; 4. Wire taking mechanism; 41. Support frame; 42. C-shaped ring; 421. Notch; 422. Head end; 423. Tail end; 424. Wire taking slot; 5. First wire rack; 6. Second wire rack; 61. Second slider; 7. Controller; 8. Cable; 9a. Third slider; 9b. Fourth slider; 9c. Fifth slider; 9d. Sixth slider. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] Figure 1 In the figure, the direction perpendicular to the paper is the Y-axis direction, and the X-axis direction and the Z-axis direction are shown in Figure 1 The coordinates in .

[0049] An embodiment of the present invention also provides a needle-punched preform, which includes a multi-layer fiber mesh layer, and the needle-punched preform has the following characteristics: each fiber mesh layer has a plurality of locking structures formed by two strands of carbon fiber lines being twisted and knotted; the locking structures and the vertical (Z-direction) parts of the two carbon fiber lines connected at both ends of the locking structures constitute a vertical fiber bundle; in each fiber mesh layer, the breakage rate of the vertical fiber bundle is less than 20%.

[0050] The fiber web layer is formed by laminating a fiber cloth and a fiber web. The fiber web is relatively loose, and the fiber cloth increases the strength of the fiber web layer.

[0051] In the current mainstream needle punch preform forming process, the vertical fiber bundles in each fiber web layer are 2.5-7 bundles / cm 2 , the proportion of unbroken vertical fiber bundles is 30-70%. In the needle-punched preform of the embodiment of the present invention, in each fiber web layer, based on the regularity and operability of the locking structure, the vertical fiber bundles are 20-25 bundles / cm2 The number of vertical fiber bundles is larger and denser, and the breakage rate of vertical fiber bundles is less than 20%, that is, the proportion of unbroken vertical fiber bundles is 80-100%, and the proportion of unbroken vertical fiber bundles is larger, and the proportion of broken vertical fiber bundles is smaller, which improves the interlayer shear mechanical properties of the fiber mesh layer. The interlayer shear mechanical properties of the fiber mesh layer can be improved by 51-62%.

[0052] In one embodiment, a plurality of the locking structures are arranged in a rectangular array in the XY plane, so as to further improve the interlayer shear mechanical properties of the fiber web layer.

[0053] In one embodiment, the fiber web layer has a thickness of 1-15 mm.

[0054] In one embodiment, the fiber web layer is provided with 10-100 layers, the thickness of the needle-punched preform is 10-80 mm, and the density of the needle-punched preform is 0.3-0.8 g / cm 3 .

[0055] The density of the needle-punched preform can be measured by the water displacement method. The number of broken vertical fiber bundles can be obtained by the following method: first carbonize the needle-punched preform, then cut the needle-punched preform vertically (in the direction of needling), take a photo to obtain a cross-sectional view, then zoom in and observe the cross-section, count the number of broken vertical fiber bundles and the total number of vertical fiber bundles, and thus calculate the proportion of broken vertical fiber bundles (broken rate of vertical fiber bundles).

[0056] The preparation of the needle-punched preform according to the embodiment of the present invention is described below in combination with a plurality of embodiments and comparative examples.

[0057] Example 1

[0058] Take 40 sheets of 24K woven cloth with a thickness of 0.6 mm and a surface density of 400 g / m2 and 24K fiber mesh with a thickness of 0.25 mm and a surface density of 140 g / m2, cut them into square pieces of 50 cm*50 cm, alternately lay the woven cloth and the fiber mesh at a rotation angle of 0° / 90° and alternately place them layer by layer to form 80 layers (40 layers of fiber mesh layers), and use the acupuncture equipment of the present invention for acupuncture, wherein the carbon fiber wire diameter model is 6k, the acupuncture rate is 0.2 cm / needle on the X-axis and Y-axis, and a needle-punched preform with an overall 80 layers is obtained, the density of which is 0.78 g / cm3, and the vertical fiber bundles are 25 bundles / cm 2 , of which the vertical carbon fiber bundles without breakage accounted for 96%, and the vertical fiber bundles with breakage accounted for 4%. Compared with the preform prepared by traditional carbon fiber flat fabric with the same specifications and process parameters, the interlaminar shear mechanical properties were improved by 62%.

[0059] Example 2

[0060] Take 40 sheets of 12K woven cloth with a thickness of 0.4mm and a surface density of 320g / m2 and 24K fiber mesh with a thickness of 0.15mm and a surface density of 80g / m2, cut them into square pieces of 50cm*50cm, and alternately lay the woven cloth and the fiber mesh at a rotation angle of 0° / 90° and stack them into 80 layers (40 layers of fiber mesh layers), and use the acupuncture equipment of the present invention for acupuncture, wherein the carbon fiber wire diameter model is 12k, and the acupuncture rate is 0.2cm / needle on the X-axis and Y-axis, to obtain a needle-punched preform with 80 layers as a whole, with a density of 0.63g / cm3 and a vertical fiber bundle of 25 bundles / cm 2 , of which the vertical carbon fiber bundles without breakage accounted for 92%, and the vertical fiber bundles with breakage accounted for 8%. Compared with the preform prepared by traditional carbon fiber flat fabric with the same specifications and process parameters, the interlayer shear mechanical properties are improved by 59%.

[0061] Example 3

[0062] Take 40 sheets of 12K woven cloth with a thickness of 0.3mm and a surface density of 220g / m2 and 24K fiber mesh with a thickness of 0.12mm and a surface density of 40g / m2, cut them into square pieces of 50cm*50cm, and alternately lay the woven cloth and the fiber mesh at a rotation angle of 0° / 90° and stack them into 80 layers (40 layers of fiber mesh layers), and use the acupuncture equipment of the present invention for acupuncture, wherein the carbon fiber wire diameter model is 6k, the acupuncture rate is 0.2cm / needle on the X-axis and Y-axis, and a needle-punched preform with an overall 80 layers is obtained, the density of which is 0.55g / cm3, and the vertical fiber bundles are 25 bundles / cm 2 , of which 80% are vertical carbon fiber bundles without breakage, and 20% are vertical fiber bundles with breakage. Compared with the preform made of traditional carbon fiber flat fabric with the same specifications and process parameters, the interlaminar shear mechanical properties are improved by 51%.

[0063] Comparative Example (Acupuncture using the traditional acupuncture machine in the background art)

[0064] Take the thickness as 0.4mm and the surface density as 320g / m 2 12K woven fabric with a thickness of 0.15mm and a surface density of 80g / m 2 40 sheets of 12K fiber mesh are cut into 50cm*50cm square pieces. The woven cloth and fiber mesh are placed alternately layer by layer at a 0° / 90° rotation angle. Each layer is needled with a traditional needle-punching machine, and the needle-punching density is controlled to 25 needles / cm 2 The fiber mesh preform with 80 layers (40 fiber mesh layers) was obtained, and its density was 0.51 g / cm 3 , vertical fiber bundles are 6.67 bundles / cm2 , among which the unbroken vertical fiber bundles accounted for 64.75%, and the broken vertical fiber bundles accounted for 35.25%.

[0065] See also Figures 1 to 3 An embodiment of the present invention provides a needling device for preparing the needling preform of the above embodiment, the needling device includes at least one needling unit 10, the needling unit 10 includes a frame 1, a lifting mechanism 2, a needle 3, a wire taking mechanism 4, a first wire rack 5 and a second wire rack 6, one end of the lifting mechanism 2 is installed on the top of the frame 1, the needle 3 is vertically installed at the bottom of the lifting mechanism 2, the lifting mechanism 2 is used to drive the needle 3 to move along the Z-axis direction, the first wire rack 5 and the second wire rack 6 are connected to the frame 1, the first wire rack 5 is used to place the first carbon fiber coil 20, and the second wire rack 6 is used to place the second carbon fiber coil 30; the wire taking mechanism 4 is rotatably connected to the second wire rack 6 and is located below the needle 3, and the needle hole 31 on the needle 3 is used to penetrate the free end of the carbon fiber wire of the first carbon fiber coil 20.

[0066] The wire taking mechanism 4 can be in the wire taking position ( Figure 1 The wire taking mechanism 4 is capable of taking off the carbon fiber wire of the first carbon fiber coil 20 when it is rotated to the wire taking position, and the carbon fiber wire of the first carbon fiber coil 20 and the carbon fiber wire of the second carbon fiber coil 30 are capable of being entangled and knotted to form a locking structure 40 when the wire taking mechanism 4 is rotated to the knotting position. The lifting mechanism 2 is capable of driving the needle 3 to move upward to bring the locking structure 40 into the fiber mesh layer 50.

[0067] In some embodiments, the multi-layer fiber web layer 50 can be pre-fixed on the frame 1, for example, fixed on a layer plate set in the frame 1, and the fiber web layer 50 can be needled by moving the needle 3 in the XY plane.

[0068] In other embodiments, the multi-layer fiber web layer 50 can be placed on a conveying platform, and the needles 3 can be stationary and moved by the conveying platform to achieve needle puncture on the fiber web layer 50.

[0069] in, Figure 3 The enlarged schematic diagram of the locking structure 40 is shown. In order to highlight the locking structure 40, the fiber web layer 50 through which the fibers pass is separated for illustration. The actual product is as follows Figure 4 As shown in the schematic diagram, the fibers forming the locking structure 40 are inserted between the woven cloth and the fiber web layer 50 .

[0070] See also Figure 4The multiple locking structures 40 of each fiber web layer 50 form a row and are located in the middle of the fiber web layer 50 in the Z-axis direction. The fiber web layer 50 can have 10-100 layers. The acupuncture device performs acupuncture layer by layer. The thickness of the fiber web layer 50 is 1-15 mm.

[0071] The planar laying directions of the fibers of the plurality of fiber web batt layers 50 are vertically staggered.

[0072] The diameter of the carbon fiber wire of the first carbon fiber coil 20 should be 3K, 6K or 12K. The diameter of the carbon fiber wire of the second carbon fiber coil 30 should be 3K, 6K or 12K.

[0073] The needling device of the embodiment of the present invention can complete the needling of a single-layer fiber mesh layer 50 by needling the fiber mesh layer 50 multiple times along the XY plane direction. After multiple layers of needling, a needling preform with a certain strength is formed. The needling preform prepared by the needling device has the following characteristics: each fiber mesh layer 50 has a plurality of locking structures 40 formed by two strands of carbon fiber wire (the carbon fiber wire of the first carbon fiber coil 20 and the carbon fiber wire of the second carbon fiber coil 30) wound and knotted, and the locking structure 40 and the vertical parts of the two strands of carbon fiber wire connected to the two ends of the locking structure 40 form a vertical fiber bundle, and the breakage rate of the vertical fiber bundle is less than 20%.

[0074] In addition, the needle punching equipment of the present invention can improve the compactness of the needle punched preform, and the proportion of radial carbon fibers is greatly increased, so that the needle punched preform formed in this way can be well formed. Moreover, each needle punching unit has only one needle 3, and the needle 3 has no barb structure, is not easy to wear, and is not easy to break during the needle punching process, which can reduce production costs. In addition, the needle punched preform prepared by the needle punching equipment also has the following characteristics: the density of the needle punched preform is 0.3-0.8g / cm 3 .

[0075] In addition, since the acupuncture device operates with a single needle, the acupuncture device does not need to be too large, can save space, and is easy to place.

[0076] In addition, the formed carbon fibers are continuous, which solves the problems of short and disordered carbon fibers in the existing needle-punched preform molding process and increases the strength of the needle-punched preform.

[0077] Figure 5This is a schematic diagram of the vertical fiber distribution formed by needle-punching three layers of carbon fiber cloth (fiber mesh layer) with an existing needle-punching machine. It can be seen that the length of the formed vertical fibers is uneven and discontinuous. The first four vertical fibers pass through the woven cloth located on the upper and lower layers, and pass through the fiber mesh in the middle, which plays a good role in enhancing the interlayer shear force, while the last three vertical fibers do not achieve the effect of passing through the upper, middle and lower layers, so they cannot better enhance the interlayer shear force. These three are the broken vertical fibers in the schematic diagram.

[0078] Figure 4 The needling effect diagram of the needling device provided in the embodiment of the present invention shows that continuous long fibers can be formed in the carbon fiber cloth layer (fiber mesh layer 50), and a regular locking structure 40 can be formed in the middle of the carbon fiber cloth layer. As the thickness of the carbon fiber cloth layer increases, a regular locking structure 40 can be formed in the carbon fiber cloth layer, which is not available in the existing needling machine. In addition, the needling device provided in the embodiment of the present invention can needle-punch multiple carbon fiber cloth layers of a certain thickness without the need for stacking needling layers one by one, which can greatly improve production efficiency compared with the existing needling machine.

[0079] The first wire rack 5 and the second wire rack 6 can be separately provided and fixedly connected to the frame 1. The first wire rack 5 and the second wire rack 6 can also be a part of the frame 1.

[0080] In one embodiment, a plurality of acupuncture units 10 are provided. The plurality of acupuncture units 10 are arranged in a rectangular array. In this way, acupuncture operations can be performed with multiple needles at the same time, which can greatly improve the working efficiency of the acupuncture device.

[0081] In one embodiment, the surface of the needle 3 is smooth, and the needle 3 has a columnar needle shaft and a conical needle tip connected to the lower end of the needle shaft. The surface of the needle 3 is smooth, and the needle 3 has no barb structure, so it is not easy to wear and tear, and is not easy to break during the acupuncture process, which can reduce the production cost.

[0082] In one embodiment, the length of the needle 3 is 50-70 mm, and the diameter of the needle rod is 2-3 mm, which can reduce the volume of the needle while ensuring the strength of the needle 3. The needle hole 31 is a circular hole or an elliptical hole, and the maximum diameter of the needle hole 31 is 1-1.5 mm, so that the carbon fiber line can pass through.

[0083] In one embodiment, see Figure 1The wire taking mechanism 4 includes a support frame 41 and a C-shaped ring 42. The support frame 41 is rotatably connected to the second wire frame 6. The C-shaped ring 42 is connected to the outer side of the support frame 41. The two sides of the notch 421 of the C-shaped ring 42 respectively form a head end 422 and a tail end 423. The head end 422 is provided with a wire taking groove 424 for taking out the carbon fiber wire of the first carbon fiber coil 20.

[0084] In one embodiment, a wire-taking driving member is further included for driving the C-shaped ring 42 to rotate. The wire-taking driving member may be, for example, a reduction motor.

[0085] In one embodiment, a controller 7 is further included, and the controller 7 is electrically connected to the lifting mechanism 2 and the wire-taking drive member through cables 8 to control the lifting and lowering of the lifting mechanism 2 and the rotation of the wire-taking drive member. The lifting mechanism 2 is a hydraulic cylinder, a pneumatic cylinder or an electric cylinder.

[0086] In one embodiment, the wire extraction groove 424 has a triangular cross-section and opens toward the notch 421 of the C-shaped ring 42 .

[0087] In one embodiment, the cross section of the wire taking groove 424 is roughly triangular, and the vertex angle of the cross section of the wire taking groove 424 is 60-90 degrees to facilitate wire taking. The radial width (the difference between the outer diameter and the inner diameter) of the C-shaped ring 42 is 2-4 mm. The radial width of the C-shaped ring 42 can be appropriately reduced while ensuring strength to reduce the weight of the C-shaped ring 42.

[0088] In one embodiment, the acupuncture device further comprises:

[0089] The first X-axis moving mechanism is used to drive the lifting mechanism to move along the X-axis direction; the first X-axis moving mechanism is a hydraulic cylinder, a pneumatic cylinder or an electric cylinder.

[0090] The first Y-axis moving mechanism is used to drive the lifting mechanism to move along the Y-axis direction; the first Y-axis moving mechanism is a hydraulic cylinder, a pneumatic cylinder or an electric cylinder

[0091] The second X-axis moving mechanism is used to drive the second wire rack to move along the X-axis direction; the second X-axis moving mechanism is a hydraulic cylinder, a pneumatic cylinder or an electric cylinder.

[0092] The second Y-axis moving mechanism is used to drive the second wire rack to move along the Y-axis direction. The second Y-axis moving mechanism is a hydraulic cylinder, a pneumatic cylinder or an electric cylinder.

[0093] See also Figure 2The frame 1 includes a top rail 11, a bottom rail 12, a first side plate 13 and a second side plate 14, wherein the first side plate 13 and the second side plate 14 extend in the Y-axis direction, and the top rail 11 and the bottom rail 12 extend in the X-direction; the upper end of the lifting mechanism 2 is slidably connected to the top rail 11 through a first slider 21, and the lower end of the second wire rack 6 is slidably connected to the bottom rail 12 through a second slider 61; the top rail 11 is slidably connected between the top of the first side plate 13 and the top of the second side plate 14. Specifically, a first rail 131 is provided on the inner side of the top of the first side plate 13, and a second rail 141 is provided on the inner side of the top of the second side plate 14. One end of the top rail 11 is slidably connected to the first rail 131 through a third slider 9a, and the other end of the top rail 11 is slidably connected to the second rail 141 through a fourth slider 9b.

[0094] The first X-direction moving mechanism can drive the lifting mechanism 2 to move along the top guide rail 11 , and the first Y-direction moving mechanism can drive the top guide rail 11 and the lifting mechanism 2 to move along the Y-axis direction.

[0095] The bottom guide rail 12 is slidably connected between the bottom of the first side panel 13 and the bottom of the second side panel 14. Specifically, a third guide rail 132 is provided inside the bottom of the first side panel 13, a fourth guide rail 142 is provided inside the bottom of the second side panel 14, one end of the bottom guide rail 12 is slidably connected to the third guide rail 132 via a fifth slider 9c, and the other end of the bottom guide rail 12 is slidably connected to the fourth guide rail 142 via a sixth slider 9d.

[0096] The second X-direction moving mechanism can drive the second wire rack 6 to move along the bottom guide rail 12 , and the second Y-direction moving mechanism can drive the bottom guide rail 12 and the second wire rack 6 to move along the Y-axis direction.

[0097] In this way, the needle 3 can move freely in the XY plane, and correspondingly, the thread taking mechanism 4 can also move freely in the XY plane. The forming of the needle-punched preform can be achieved by a needle-punching unit 10 .

[0098] Of course, a plurality of acupuncture units 10 may also move along the XY plane in their respective regions.

[0099] The density of acupuncture can be set by the controller 7, and the fiber web layer 50 does not need to be moved. The needle 3 can completely acupuncture the fiber web layer 50 on the layer through the first X-direction moving mechanism and the first Y-direction moving mechanism. After acupuncture in the X-axis direction, it can also acupuncture in the Y-axis direction, so that the carbon fiber wires in the X-axis and Y-axis of the fiber plane can be overlapped, and the strength is higher.

[0100] Of course, the first X-direction moving mechanism, the first Y-direction moving mechanism, the second X-direction moving mechanism and the second Y-direction moving mechanism may be eliminated, and the needle 3 may remain stationary while the fiber web layer 50 may move in the XY plane.

[0101] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A needle-punched preform, characterized in that: The needle-punched preform comprises a multi-layered fiber web layer, and the needle-punched preform has the following characteristics: Each fiber web layer has a plurality of locking structures formed by two strands of carbon fiber lines being twisted and knotted, and the locking structures and the vertical parts of the two strands of carbon fiber lines connected at both ends of the locking structures form a vertical fiber bundle; In each fiber web layer, the breakage rate of the vertical fiber bundles is less than 20%.

2. The needle-punched preform according to claim 1, characterized in that: In each fiber web layer, the vertical fiber bundles are 20-25 bundles / cm 2 .

3. The needle-punched preform according to claim 1, characterized in that: The multiple locking structures are arranged in a rectangular array in the XY plane.

4. The needle-punched preform according to claim 1, characterized in that: The thickness of the fiber web layer is 1-15 mm.

5. The needle-punched preform according to claim 1, characterized in that: The fiber web layer is provided with 10-100 layers, the thickness of the needle-punched preform is 10-80 mm, and the density of the needle-punched preform is 0.3-0.8 g / cm 3 .

6. An acupuncture device, characterized in that: Used for preparing the needle-punched preform according to any one of claims 1 to 5, the needle-punching device comprises at least one needle-punching unit, the needle-punching unit comprises a frame, a lifting mechanism, a needle, a wire taking mechanism, a first wire rack and a second wire rack, one end of the lifting mechanism is mounted on the top of the frame, the needle is vertically mounted on the bottom of the lifting mechanism, the lifting mechanism is used to drive the needle to move along the Z-axis direction, the first wire rack and the second wire rack are connected to the frame, the first wire rack is used to place a first carbon fiber coil, and the second wire rack is used to place a second carbon fiber coil; The thread taking mechanism is rotatably connected to the second thread rack and is located below the needle, and the needle hole on the needle is used to penetrate the free end of the carbon fiber thread of the first carbon fiber coil; The wire taking mechanism can rotate between a wire taking position and a knotting position. When the wire taking mechanism rotates to the wire taking position, the carbon fiber wire of the first carbon fiber coil can be taken out. When the wire taking mechanism rotates to the knotting position, the carbon fiber wire of the first carbon fiber coil and the carbon fiber wire of the second carbon fiber coil can be entangled and knotted to form a locking structure. The lifting mechanism can drive the needle to move upward to bring the locking structure into the fiber mesh layer.

7. The acupuncture device according to claim 6, characterized in that The acupuncture units are provided in plurality.

8. The acupuncture device according to claim 6, characterized in that The surface of the needle is smooth, and the needle comprises a columnar needle rod and a conical needle tip connected to the lower end of the needle rod.

9. The acupuncture device according to claim 8, characterized in that The length of the needle is 50-70 mm, and the diameter of the needle shaft is 2-3 mm; The pinhole is a circular hole or an elliptical hole, and the size of the pinhole at the maximum aperture is 1-1.5 mm.

10. The acupuncture device according to claim 6, characterized in that The wire taking mechanism includes a support frame and a C-shaped ring, wherein the support frame is rotatably connected to the second wire frame, the C-shaped ring is connected to the outside of the support frame, and the two sides of the notch of the C-shaped ring respectively form a head end and a tail end, and the head end is provided with a wire taking groove for taking out the carbon fiber wire of the first carbon fiber coil; It also includes a wire taking driving member for driving the C-shaped ring to rotate.

11. The acupuncture device according to claim 10, characterized in that Also includes: A controller is electrically connected to the lifting mechanism and the wire-taking driving component respectively to control the lifting and lowering of the lifting mechanism and the rotation of the wire-taking driving component.

12. The acupuncture device according to claim 10, characterized in that The cross section of the wire taking groove is triangular and the opening faces the notch of the C-shaped ring.

13. The acupuncture device according to claim 10, characterized in that The top angle of the cross section of the wire taking slot is 60-90 degrees; The radial width of the C-shaped ring is 2-4 mm.

14. The acupuncture device according to claim 6, characterized in that Also includes: A first X-axis moving mechanism, used for driving the lifting mechanism to move along the X-axis direction; A first Y-axis moving mechanism, used for driving the lifting mechanism to move along the Y-axis direction; A second X-axis moving mechanism, used for driving the second wire rack to move along the X-axis direction; The second Y-axis moving mechanism is used to drive the second wire rack to move along the Y-axis direction.

15. The acupuncture device according to claim 14, characterized in that The frame includes a top rail, a bottom rail, a first side plate and a second side plate, the first side plate and the second side plate extend along the Y-axis direction, and the top rail and the bottom rail extend along the X-direction; the upper end of the lifting mechanism is slidably connected to the top rail, and the lower end of the second wire rack is slidably connected to the bottom rail; The top guide rail is slidably connected between the top of the first side plate and the top of the second side plate, the first X-axis moving mechanism can drive the lifting mechanism to move along the top guide rail, and the first Y-axis moving mechanism can drive the top guide rail and the lifting mechanism to move along the Y-axis direction; The bottom guide rail is slidably connected between the bottom of the first side plate and the bottom of the second side plate, the second X-direction moving mechanism can drive the second wire rack to move along the bottom guide rail, and the second Y-direction moving mechanism can drive the bottom guide rail and the second wire rack to move along the Y-axis direction.

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