Device and method for implanting Z-direction yarn in high-thickness preform

Abstract

The invention discloses a device and method for implanting Z-direction yarn into a high-thickness preform. The device comprises a felting needle, a needle guide assembly, a long-stroke machine head, a linear module and an auxiliary movement supporting module. The needle guide assembly is installed on the front side of the long-stroke machine head and used for supporting the pricking needle to linearly move front and back in the y-axis direction in a sliding mode. The long-stroke machine head comprises a machine base, a needle tube, a connecting rod assembly and a handle, one end of the machine base is supported on the linear module and is driven by the linear module to linearly move left and right in the x-axis direction, and the other end of the machine base is slidably installed on the auxiliary movement supporting module; the front end of the needle tube is coaxially and fixedly connected with the pricking needle, and the rear end of the needle tube is hinged to the connecting rod assembly which is driven by the handle to rotate, so that the needle tube drives the pricking needle to linearly move back and forth. According to the method, the Z-direction yarn can be directly implanted, the implanting efficiency is high, stitches are uniform, and a plane cloth layer is not damaged.

Description

Technical Field

[0001] The invention relates to the technical field of fiber preform needle punching, in particular to a device and a method for implanting Z-direction yarns in a high-thickness preform. Background Art

[0002] Evenly implanting Z-direction yarns inside the preform can strengthen the composite material in the normal direction of the ply plane, thereby improving the damage tolerance between material layers. Stitching technology is a new technology developed to address the shortcomings of traditional preform molding methods and is a typical Z-direction yarn implantation technology.

[0003] The stitching process has been widely used in load-bearing and functional components in the fields of aerospace, shipbuilding, etc. due to its remarkable characteristics such as rapid prototyping, high-precision profiling, and excellent performance of preform composite materials. It is one of the main processes for forming preforms for advanced composite materials in the future. However, with the changes in application requirements in the material field, the application demand for high-thickness stitched preforms represented by ≥60mm has increased significantly. Conventional stitching processes and equipment face problems such as messy stitching stitches, difficult to control the verticality in the thickness direction, and instability of the stitching needle. They may even be unable to complete the stitching, which directly affects the final composite material performance and the application and promotion of the process. Therefore, the preparation of high-thickness preforms poses a great challenge to the stitching process.

[0004] In the prior art, for Z-direction yarn implantation in a high-thickness preform, it is first necessary to pre-make a hole in the preform, and then use a suture needle to manually drive the yarn through the pre-made hole to achieve the Z-direction yarn implantation; however, for high-thickness preforms, the existing process has two major problems: First, due to the large thickness of the preform, if the punching needle is relatively slender, it is very easy for the needle to shift during punching; if the needle is thicker and the needle hole formed is larger, the needle will seriously damage the planar fiber, making it difficult to meet the performance requirements of the composite material; second, due to the flexibility of the preform, the preformed hole is easy to close automatically after a period of time, and the worker cannot accurately find the position of the preformed hole during suture, which affects the suture efficiency and suture quality. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a device and method for implanting Z-direction yarns in a high-thickness preform.

[0006] The specific technical solution adopted by the present invention is as follows:

[0007] A device for implanting Z-direction yarn in a high-thickness preform, comprising a needle, a needle guide assembly, a long-stroke head, a linear module, and an auxiliary motion support module;

[0008] The needle guide assembly is installed on the front side of the long-stroke machine head and is used to slide and support the needle to move forward and backward in a straight line along the y-axis direction;

[0009] The long-stroke head includes a machine base, a needle tube, a connecting rod assembly and a handle. One end of the machine base is supported on a linear module, which is driven by the linear module to move left and right along the x-axis direction, and the other end can be slidably installed on an auxiliary motion support module; the needle tube is slidably installed on the machine base along the y-axis direction, the front end of the needle tube is coaxially fixedly connected to the acupuncture needle, and the rear end is hinged to the connecting rod assembly. The connecting rod assembly is driven to rotate by the handle, thereby driving the acupuncture needle to move forward and backward linearly through the needle tube.

[0010] Furthermore, the needle guide assembly includes a guide frame and a guide head; the first guide frame is arranged upwardly and tilted, and its lower end is fixed on the long-stroke head, and the guide head is fixedly installed on the upper end of the first guide frame, and the central part of the guide head is provided with a central through hole adapted to the puncture needle.

[0011] Furthermore, a first waist-shaped hole is vertically opened at the lower end of the first guide frame, and the first guide frame is fixed to the long-stroke machine head by screws passing through the first waist-shaped hole.

[0012] Furthermore, the needle guide assembly includes a second guide frame, a guide head and an adjustment frame. The adjustment frame is horizontally arranged, and its rear end is fixed on the long-stroke machine head. The adjustment frame is provided with a long groove extending along the y-axis direction. The second guide frame is connected to the adjustment frame by a screw passing through the long groove. The guide head is fixedly installed on the upper end of the second guide frame, and the central part of the guide head is provided with a central through hole adapted to the puncture needle.

[0013] Furthermore, a second waist-shaped hole is vertically opened at the rear end of the adjustment frame, and the adjustment frame is fixed to the long-stroke machine head by means of screws passing through the second waist-shaped hole.

[0014] Furthermore, the guide head is made of Teflon material, and the guide head is connected to the first guide frame and the second guide frame through threads.

[0015] Furthermore, a needle hole is arranged on the head of the needle, and a notch is arranged on one side of the needle hole.

[0016] Furthermore, the linear module is of synchronous belt type, and the synchronous belt is driven by a servo motor to rotate, thereby driving the long-stroke machine head to move linearly left and right along the x-axis direction.

[0017] Furthermore, the auxiliary motion support module includes a support frame, a slider and a linear guide rail. The linear guide rail is arranged parallel to the linear module. The slider is slidably installed on the linear guide rail. The support frame is fixedly installed on the slider. The upper end of the support frame is fixedly supported on the rear end of the base of the machine base.

[0018] A method for implanting Z-direction yarns in a high-thickness preform, using any of the above-mentioned devices, specifically comprising the following steps:

[0019] (1) The high-thickness preform is clamped and fixed vertically on the existing flat-plate forming machine, and the surface of the preform is parallel to the x-axis;

[0020] (2) Pass the needle through the guide head of the needle guide assembly and fix it on the needle tube. Adjust the position of the needle guide assembly so that the guide head and the needle are coaxial. Lock and fix the needle guide assembly to the machine base. Take a piece of cotton thread, tie one end of it to the Z-direction yarn, and tie a knot with the other end. Put the circle into the needle hole from the notch of the needle.

[0021] (3) Push the handle to make the needle drive the Z-direction yarn to penetrate the preform vertically from the front;

[0022] (4) Take out the cotton thread from the notch on the reverse side of the preform, separate the Z-direction yarn from the needle, tighten the Z-direction yarn in the preform, and pull the handle to make the needle withdraw from the preform;

[0023] (5) Start the linear module to drive the long-stroke machine head to move a yarn implantation spacing in the positive direction of the x-axis;

[0024] (6) Push the handle again to make the needle pierce the preform vertically from the front side, and insert the cotton thread into the needle hole on the back side of the preform;

[0025] (7) Pull the handle to make the needle withdraw from the preform, and the needle drives the Z-direction yarn to be vertically implanted into the preform from the reverse side; remove the cotton thread from the needle hole on the front side of the preform;

[0026] (8) Start the linear module to drive the long-stroke machine head to move a yarn implantation spacing in the positive direction of the x-axis;

[0027] (9) Repeat steps (3) to (9) until a row of carbon fiber yarns is implanted;

[0028] (10), moving the preform along the z-axis direction by a yarn implantation spacing;

[0029] (11) Repeat steps (3) to (10) until all Z-direction yarns are implanted, and then test and package the samples.

[0030] The beneficial effects of the present invention are:

[0031] 1. The device of the present invention can be used to directly introduce Z-direction yarns while performing needle punching on a high-thickness preform, without the need to pre-make holes in the preform, thereby improving the implantation efficiency of the Z-direction yarns and avoiding the problem of easy closure of the preformed holes.

[0032] 2. The present invention provides a needle guide assembly, which can always provide support for the slender needle, reduce the cantilever length of the needle, reduce the instability of the needle, reduce the offset of the needle, and improve the uniformity of the needle; and avoid the problem of serious damage to the flat cloth layer when using a coarse needle.

[0033] 3. The present invention forms a simply supported beam structure of the machine head by arranging a linear module and an auxiliary support module, thereby reducing the shaking of the long-stroke machine head when the needle penetrates the preform, enhancing its stability, further ensuring the verticality and uniformity of the Z-direction yarn, and improving the preparation quality of high-thickness preforms.

[0034] 4. The method of the present invention can realize the direct implantation of Z-direction yarns and the continuous implantation of high-performance fibers along the Z direction of high-thickness preforms in a "J-shaped" manner, thereby improving the preparation efficiency of high-thickness preforms and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural diagram of the device of the present invention.

[0036] Figure 2 It is a partial structural diagram of the needle of the present invention.

[0037] Figure 3 It is a structural diagram of the fixed guide assembly of the present invention.

[0038] Figure 4 It is a structural diagram of the adjustable guide assembly of the present invention.

[0039] Figure 5 This is a diagram of the needle hanging yarn of the present invention.

[0040] Figure 6 The single-cycle process diagram of the present invention for implanting Z-direction yarns into a high-thickness preform is shown.

[0041] Figure 7 The present invention is a process flow chart for implanting Z-direction yarns into a high-thickness preform.

[0042] FIG8( a ) is a front view of a high-thickness preform after Z-direction yarn implantation according to the present invention.

[0043] FIG8( b ) is a photograph of the reverse side of the high-thickness preform after Z-direction yarn implantation according to the present invention. DETAILED DESCRIPTION

[0044] The specific implementation modes of the present invention are described below to facilitate those skilled in the art to understand the present invention. Detailed implementation modes and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0045] See also Figure 1-Figure 4 , a device for implanting Z-direction yarn in a high-thickness preform, comprising a needle 1, a needle guide assembly 2, a long-stroke head 3, a linear module 4 and an auxiliary motion support module 5.

[0046] The long-stroke machine head 3 includes a machine base 33, a needle tube 31, a connecting rod assembly 34 and a handle 32. One end of the machine base 33 is supported on the linear module 4, and is driven by the linear module 4 to move linearly along the x-axis, that is, to move left and right. The other end of the machine base 33 can be slidably mounted on the auxiliary motion support module 5. The machine base 33 includes a base and a sliding support seat fixed on the top surface of the base. One end of the sliding support seat is provided with a through hole extending along the y-axis direction, and the other end is provided with a connecting rod mounting support. The needle tube 31 is slidably mounted in the through hole of the sliding support seat. The front end of the needle tube 31 is coaxially fixedly connected to the needle 1, and the rear end is connected to the connecting rod assembly 34. The connecting rod assembly 34 includes a first connecting rod and a second connecting rod. The front end of the first connecting rod is hinged to the needle tube 31, and the rear end is rotatably connected to the second connecting rod through axis A. The rear end of the second connecting rod is rotatably connected to the connecting rod mounting support through axis B. The handle 32 is fixedly mounted on the axis A. The second connecting rod is driven to rotate around the axis B by the handle 32, thereby driving the needle tube 31 to move linearly along the y-axis direction through the first connecting rod, that is, the needle tube 31 drives the needle 1 to move linearly forward and backward.

[0047] The linear module 4 is of prior art, and may be a synchronous belt type or a lead screw type linear module. In this embodiment, the linear module 4 is of a synchronous belt type, and the servo motor 41 drives the synchronous belt to rotate, driving the long-stroke machine head 3 to move left and right along the x-axis.

[0048] The auxiliary motion support module 5 includes a support frame 51, a slider 52 and a linear guide 53. The linear guide 53 is arranged parallel to the linear module 4, the slider 52 is slidably mounted on the linear guide 53, and the support frame 51 is fixedly mounted above the slider 52 by screws. The upper end of the support frame 51 is fixedly supported on the rear end of the base of the machine base 33.

[0049] The needle guide assembly 2 can be a fixed guide assembly or an adjustable guide assembly.

[0050] See also Figure 3 The fixed guide assembly includes a first guide frame 21 and a guide head 22; the first guide frame 21 is Z-shaped as a whole, including an upper end and a lower end, the upper end and the lower end are connected by an inclined middle portion, the upper end is provided with a threaded hole, and the lower end is provided with a waist-shaped hole 211.

[0051] The guide head 22 is made of Teflon material and is generally cylindrical with one end larger than the other. The center of the cylinder is provided with a central through hole 221 adapted to the needle 1, and the small cylindrical section is provided with an external thread adapted to the first guide frame 22. The end surface of the large cylindrical section is provided with a deep and long groove 222 to facilitate the installation of the guide head 22.

[0052] The guide head 22 is threadedly connected to the upper end of the first guide frame 21. The first guide frame 21 is fixed to the front side of the machine base 33 by screws passing through the waist-shaped hole 211. The installation height of the first guide frame 21 is adjusted by the screws so that the axis of the central through hole 221 is colinear with the axis of the through hole of the sliding support seat.

[0053] The needle 1 slides through the central through hole 221 of the guide head 22, and the tail end is inserted and fixed on the front end of the needle tube 31. Figure 2 The head of the needle 1 is provided with a needle hole, and a notch 11 is provided on one side of the needle hole.

[0054] See also Figure 4 The adjustable guide assembly includes a second guide frame 23, a guide head 22 and an adjustment frame 24; the structure of the guide head 22 is consistent with that of the guide head in the fixed guide assembly. The adjustment frame 24 is L-shaped, and its horizontal portion is provided with a long slot extending along the y-axis direction. The second guide frame 23 is connected to the adjustment frame 24 by screws passing through the long slot. The front and rear positions of the second guide frame 23 can be adjusted by the screws to adapt to needles 1 of different lengths. The connection method between the second guide frame 23 and the guide head 22 is the same as that of the fixed guide assembly. The second guide frame 23 is fixed to the front side of the machine base 33 through the vertical portion of the adjustment frame 24. The vertical portion of the adjustment frame 24 can also be provided with a waist-shaped hole (not shown in the figure) with the same structure as the first guide frame 21, so as to facilitate the adjustment of the installation height of the second guide frame 23.

[0055] The needling method for a high-thickness preform of the present invention is described below by means of specific embodiments.

[0056] Example 1

[0057] See also Figure 5-Figure 7 , a method for implanting Z-direction yarns in a carbon fiber preform with a length of 2000 mm and a thickness of 60 mm using the above device, wherein the Z-direction yarn implantation spacing of the preform is 6×6 mm, and the specific steps are as follows:

[0058] (1) A carbon fiber preform with a thickness of 60 mm is vertically clamped and fixed on an existing flat-plate forming machine, and the surface of the carbon fiber needle-punched preform is parallel to the x-axis line;

[0059] (2) Pass a stainless steel needle 1 with a diameter of 1.6 mm through the guide head 22 of the needle guide assembly 2 and fix it on the needle tube 31. Adjust the position of the guide frame so that the guide head 22 is coaxial with the needle 1, and lock the needle guide assembly to the machine base; take a piece of cotton thread, tie one end of it to the carbon fiber yarn, and tie a knot with the other end, and insert the circle into the needle hole from the notch of the needle 1;

[0060] (3) Push the handle 32 so that the needle 1 drives the carbon fiber yarn to penetrate the preform vertically from the front;

[0061] (4) Take out the cotton thread from the notch on the reverse side of the preform, so as to separate the carbon fiber yarn from the needle 1, tighten the carbon fiber yarn in the preform, and pull the handle 32 to withdraw the needle 1 from the preform;

[0062] (5) Start the servo motor 41, and the linear module 4 drives the long-stroke head 3 to move 6 mm in the positive direction along the x-axis;

[0063] (6) Push the handle 32 again to make the needle 1 vertically penetrate the preform from the front side, and insert the cotton thread into the needle hole on the back side of the preform;

[0064] (7) Pull the handle 32 to make the needle 1 withdraw from the preform, and the needle 1 drives the carbon fiber yarn to vertically penetrate the preform from the back side; remove the cotton thread from the needle hole on the front side of the preform;

[0065] (8) Start the servo motor 41, and the linear module 4 drives the long-stroke head 3 to move 6 mm in the positive direction along the x-axis;

[0066] (9) Repeat steps (3) to (9) until a row of carbon fiber yarns is implanted;

[0067] (10) Move the preform 6 mm along the z-axis direction;

[0068] (11) Repeat steps (3) to (10) until all carbon fiber yarns are implanted, and then take samples for testing and packaging.

[0069] The stitching effects on the front and back sides of the high-thickness preform after the Z-direction yarn is implanted are shown in Figures 8(a) and 8(b). The red circles are the insertion positions of the needles. It can be seen from the figures that the Z-direction yarn is implanted in the high-thickness preform by the method of the present invention. The needle positions on the front and back sides of the obtained high-thickness preform are basically coincident, indicating that the Z-direction yarn implantation of the present invention has a high verticality and uniform stitching on the front and back sides.

Claims

1. A device for implanting Z-direction yarns in a high-thickness preform, characterized in that: It comprises a needle (1), a needle guide assembly (2), a long-stroke handpiece (3), a linear module (4) and an auxiliary motion support module (5); The needle guide assembly (2) is installed on the front side of the long-stroke head (3) and is used to slide and support the needle (1) to move forward and backward in a straight line along the y-axis direction; The long-stroke machine head (3) comprises a machine base (33), a needle tube (31), a connecting rod assembly (34) and a handle (32). One end of the machine base (33) is supported on a linear module (4) and driven by the linear module to move linearly left and right along the x-axis direction, and the other end can be slidably mounted on an auxiliary motion support module (5); the needle tube (31) is slidably mounted on the machine base (33) along the y-axis direction, the front end of the needle tube (31) is coaxially fixedly connected to the needle (1), and the rear end is hinged to the connecting rod assembly (34). The connecting rod assembly (34) is driven to rotate by the handle (32), thereby driving the needle (1) to move linearly forward and backward through the needle tube (31).

2. A device for implanting Z-direction yarns in a high-thickness preform according to claim 1, characterized in that: The needle guide assembly (2) comprises a guide frame and a guide head; the first guide frame is arranged to be inclined upward, and its lower end is fixed on the long-stroke machine head (3); the guide head is fixedly installed on the upper end of the first guide frame, and the central part of the guide head is provided with a central through hole adapted to the puncture needle (1).

3. A device for implanting Z-direction yarns in a high-thickness preform according to claim 2, characterized in that: A first waist-shaped hole is vertically opened at the lower end of the first guide frame, and the first guide frame is fixed on the long-stroke machine head (3) by means of screws passing through the first waist-shaped hole.

4. The device for implanting Z-direction yarns in a high-thickness preform according to claim 1, characterized in that: The needle guide assembly (2) comprises a second guide frame, a guide head and an adjustment frame. The adjustment frame is arranged horizontally, and its rear end is fixed on the long-stroke machine head (3). The adjustment frame is provided with a long slot extending along the y-axis direction. The second guide frame is connected to the adjustment frame by a screw passing through the long slot. The guide head is fixedly mounted on the upper end of the second guide frame. The central part of the guide head is provided with a central through hole adapted to the puncture needle (1).

5. A device for implanting Z-direction yarns in a high-thickness preform according to claim 4, characterized in that: A second waist-shaped hole is vertically opened at the rear end of the adjustment frame, and the adjustment frame is fixed on the long-stroke machine head (3) by means of screws passing through the second waist-shaped hole.

6. A device for implanting Z-direction yarns in a high-thickness preform according to claim 2 or 4, characterized in that: The guide head is made of Teflon material, and the guide head is connected to the first guide frame and the second guide frame through threads.

7. The device for implanting Z-direction yarns in a high-thickness preform according to claim 1, characterized in that: The head of the needle (1) is provided with a needle hole, and a notch (11) is provided on one side of the needle hole.

8. The device for implanting Z-direction yarns in a high-thickness preform according to claim 1, characterized in that: The linear module (4) is of a synchronous belt type, and the synchronous belt is driven by a servo motor (41) to rotate, thereby driving the long-stroke machine head (3) to move linearly left and right along the x-axis direction.

9. The device for implanting Z-direction yarns in a high-thickness preform according to claim 1, characterized in that: The auxiliary motion support module (5) comprises a support frame (51), a slider (52) and a linear guide rail (53), wherein the linear guide rail (53) is arranged in parallel with the linear module (4), the slider (52) is slidably mounted on the linear guide rail (53), the support frame (51) is fixedly mounted on the slider (52), and the upper end of the support frame (51) is fixedly supported on the rear end of the base of the machine base (33).

10. A method for implanting Z-direction yarns in a high thickness preform, characterized in that: Using the device according to any one of claims 1 to 9, specifically comprising the following steps: (1) The high-thickness preform is clamped and fixed vertically on the existing flat-plate forming machine, and the surface of the preform is parallel to the x-axis; (2) Pass the needle through the guide head of the needle guide assembly and fix it on the needle tube. Adjust the position of the needle guide assembly so that the guide head and the needle are coaxial. Lock and fix the needle guide assembly to the machine base. Take a piece of cotton thread, tie one end of it to the Z-direction yarn, and tie a knot with the other end. Put the circle into the needle hole from the notch of the needle. (3) Push the handle to make the needle drive the Z-direction yarn to penetrate the preform vertically from the front; (4) Take out the cotton thread from the notch on the reverse side of the preform, separate the Z-direction yarn from the needle, tighten the Z-direction yarn in the preform, and pull the handle to make the needle withdraw from the preform; (5) Start the linear module to drive the long-stroke machine head to move a yarn implantation spacing in the positive direction of the x-axis; (6) Push the handle again to make the needle pierce the preform vertically from the front side, and insert the cotton thread into the needle hole on the back side of the preform; (7) Pull the handle to make the needle withdraw from the preform, and the needle drives the Z-direction yarn to vertically penetrate the preform from the back side; remove the cotton thread from the needle hole on the front side of the preform; (8) Start the linear module to drive the long-stroke machine head to move a yarn implantation spacing in the positive direction of the x-axis; (9) Repeat steps (3) to (9) until a row of carbon fiber yarns is implanted; (10), moving the preform along the z-axis direction by a yarn implantation spacing; (11) Repeat steps (3) to (10) until all Z-direction yarns are implanted, and then test and package the samples.

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