Molded short-cut fiber mat discharge apparatus and fiber orientation control method

Abstract

This invention relates to the field of composite material compression molding technology, and provides a compression molding chopped fiber sheet discharge device, including a frame body with two longitudinal beams mounted on it. A transverse beam is provided between the two beams, and a longitudinal sliding sleeve is fixed to each end of the transverse beam, slidingly engaging the longitudinal beams. The transverse beam is slidably engaged with the transverse sliding sleeve. A reversing motor is fixed to the transverse sliding sleeve, and the reversing motor is driven and connected to a material box. A discharge pipe is provided at the bottom of the material box. One end of the discharge pipe has an inlet connected to the material box, and the other end has a discharge nozzle. The cross-sectional shape of the discharge nozzle is similar to the cross-sectional shape of the chopped fiber sheet. The discharge pipe is configured to guide the chopped fiber sheet, causing it to flow out of the discharge nozzle in a specific orientation. Thus, this invention guides the chopped fiber sheet through the discharge pipe and simultaneously sets the shape of the discharge nozzle to ensure that the flowing chopped fiber sheet has a consistent orientation. After molding, the product has a consistent fiber orientation and good mechanical properties. This invention also provides a fiber orientation control method.

Description

Technical Field

[0001] This invention belongs to the field of composite material compression molding technology, and particularly relates to a compression molding short fiber sheet discharge device and a fiber orientation control method. Background Technology

[0002] Short-cut thermoplastic prepreg sheets can be molded into more complex shapes, such as cross-stiffened panels, and are widely used in aerospace, automotive lightweighting and other fields. Traditional compression molding usually uses randomly laid-out short-cut prepreg sheets with random fiber orientation, resulting in low strength utilization along the length of the stiffeners.

[0003] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0004] To address the aforementioned shortcomings, this invention primarily provides a device for discharging molded chopped fiber sheets, solving the technical problem of being unable to control the fiber orientation during the laying process of chopped prepreg sheets.

[0005] To address the aforementioned problems, this invention provides a device for discharging molded chopped fiber sheets, comprising a frame body with two longitudinal beams mounted on it; a transverse beam is provided between the two longitudinal beams, and a longitudinal sliding sleeve is fixed to each end of the transverse beam, the longitudinal sliding sleeve slidably engaging the corresponding longitudinal beam; a longitudinal sliding screw, parallel to the longitudinal beams and threaded through the longitudinal sliding sleeve, is also rotatably mounted on the frame body; a longitudinal sliding motor, drivingly connected to the longitudinal sliding screw, is also installed on the frame body. The transverse beam is slidably sleeved with a transverse sliding sleeve, and a transverse sliding screw parallel to the transverse beam and threaded through the transverse sliding sleeve is rotatably mounted on the frame body; a transverse motor that is driven and connected to the transverse sliding screw is also installed on the frame body. A reversing motor is fixed on the transverse sliding sleeve, and the reversing motor is connected to the material box. A discharge pipe is provided at the bottom of the material box. One end of the discharge pipe has an inlet connected to the material box, and the other end has an outlet. The cross-sectional area of ​​the discharge pipe decreases continuously from the inlet to the outlet. The cross-sectional shape of the outlet is similar to that of the material sheet. The discharge pipe is configured to guide the material sheet so that it flows out of the outlet in a specific direction.

[0006] According to the molding chopped fiber sheet discharging device of the present invention, the sheet is rectangular, and the cross-sectional shape of the discharging nozzle is similar to the cross-sectional shape of the sheet along its length.

[0007] According to the molding chopped fiber sheet discharging device of the present invention, a longitudinal rail that slides and engages with a longitudinal sliding sleeve is fixed on the longitudinal beam, and a transverse rail that slides and engages with a transverse sliding sleeve is fixed on the transverse beam.

[0008] According to the molding chopped fiber sheet discharging device of the present invention, one side of the frame body has a clearance notch.

[0009] According to the molding chopped fiber sheet discharge device of the present invention, two vertical beams are provided on both sides of the frame body, and a vertical sliding plate is slidably installed on the two vertical beams on the same side; the two ends of the longitudinal beam are fixed on the vertical sliding plate on the corresponding side.

[0010] According to the molding chopped fiber sheet discharge device of the present invention, the top of the two vertical beams located on the same side are connected to a reinforcing beam, and a vertical moving electric cylinder is installed on the reinforcing beam; a horizontally arranged fixing plate is fixed on the vertical moving plate, and the vertical moving electric cylinder is connected to the fixing plate.

[0011] According to the molding chopped fiber sheet discharge device of the present invention, the material box is provided with a feeding port, and a vibrator that abuts against the discharge pipe is installed on the material box; a feeder is provided at the connection position between the material box and the discharge pipe, and a feeder motor that drives the feeder to rotate is provided outside the material box.

[0012] According to the molding chopped fiber sheet discharging device of the present invention, the vibrator is an ultrasonic vibrator; a mounting frame is fixed on the material box, and the vibrator is fixed on the mounting frame.

[0013] A fiber orientation control method based on the emission device, characterized by comprising the following steps: S1, load the material sheet into the material box; the longitudinal and transverse motors move to move the transverse sliding sleeve to the feeding position, and the discharge nozzle is located directly above one end of a longitudinal groove of the forming mold, which is the feeding starting point; S2, Set the rotation speed of the feeder so that the flow rate of the material sheet is q. m ; S3, start the vibrator and adjust its vibration frequency to 20 ~ 40 kHz and amplitude to 0.05 ~ 0.15 mm; S4, the discharge nozzle continuously feeds from the feeding start point to the feeding end point, completing the feeding of the longitudinal trough; Control the travel speed v of the hopper m =L*q m / M; where L is the feeding stroke of the nozzle and M is the total mass of the added material; S5, Repeat steps S1 to S4 to complete the feeding of other longitudinal troughs; In S6, the direction changing motor is actuated to rotate the orientation of the discharge nozzle by 90°, and the steps S1 to S4 are repeated to complete the feeding of the transverse groove.

[0014] According to the fiber orientation control method of the present invention, the material sheet has a length l, a width w, and a thickness t; the width of the discharge nozzle satisfies: w<w0<l; the height of the discharge nozzle satisfies: t<t0<w; the height of the discharge nozzle from the material dropping position is H=k*l, where k is in the range of 0.5 to 2.

[0015] In summary, according to the chopped fiber material sheet discharging device for compression molding of the present invention, the material sheet is guided by the discharge pipe, and the shape of the discharge nozzle is set at the same time, so that the discharged material sheets have a consistent orientation. After molding, the product has consistent fiber orientation and good mechanical properties. The present invention also provides a fiber orientation control method. Brief Description of the Drawings

[0016] Figure 1 is a schematic structural view of the chopped fiber material sheet discharging device for compression molding of the present invention; Figure 2 is Figure 1 a schematic structural view in the direction A in the drawing; Figure 3 is Figure 2 a schematic structural view of a partial region in the drawing; Figure 4 is Figure 3 a schematic sectional structural view of the drawing; Figure 5 is Figure 4 a schematic structural view of region D in the drawing; Figure 6 is Figure 4 a schematic sectional structural view in the direction C in the drawing; Figure 7 is Figure 2 a schematic structural view in the direction B in the drawing; In the drawings: 1- frame body, 10- yielding notch, 11- vertical beam, 111- reinforcing beam, 112- vertical rail; 12- vertical moving plate, 121- fixed plate, 122- vertical moving electric cylinder; 13- longitudinal beam, 131- longitudinal moving lead screw, 132- longitudinal moving motor, 133- longitudinal moving sliding sleeve, 134- longitudinal rail; 14- transverse beam, 141- transverse moving lead screw, 142- transverse moving motor, 143- transverse moving sliding sleeve, 144- transverse rail; 2- material box, 21- feeding port, 22- direction changing motor, 23- material poking device, 231- material poking motor; 3- forming mold, 31- longitudinal groove, 32- transverse groove; 4- discharge pipe, 41- vibrator, 42- mounting frame, 43- discharge nozzle; 100- material sheet. Detailed Description of the Embodiments

[0017] Refer to Figure 1This invention provides a device for discharging molded chopped fiber sheets, including a frame body 1, on which two longitudinal beams 13 are mounted; combined with Figure 2 A transverse beam 14 is provided between the two longitudinal beams 13. A longitudinal sliding sleeve 133 is fixed to each end of the transverse beam 14. The longitudinal sliding sleeve 133 slidably sleeves the longitudinal beam 13 on the corresponding side. A longitudinal sliding screw 131 parallel to the longitudinal beam 13 and threaded through the longitudinal sliding sleeve 133 is also rotatably mounted on the frame body 1. A longitudinal motor 132 that is driven and connected to the longitudinal sliding screw 131 is also installed on the frame body 1. The two longitudinal motors 132 rotate synchronously, which can drive the two longitudinal lead screws 131 to rotate synchronously in the forward or reverse direction, thereby driving the transverse beam 14 to move along the longitudinal beam 13.

[0018] The transverse beam 14 is slidably sleeved with the transverse sliding sleeve 143. The frame body 1 is also rotatably mounted with a transverse sliding screw 141 parallel to the transverse beam 14 and threaded through the transverse sliding sleeve 143. The frame body 1 is also equipped with a transverse sliding motor 142 that is connected to the transverse sliding screw 141. The transverse motor 142 can drive the transverse lead screw 141 to rotate in the forward or reverse direction, so that the transverse sliding sleeve 143 moves along the transverse beam 14.

[0019] See Figure 3 A reversing motor 22 is fixed on the transverse sliding sleeve 143. The reversing motor 22 is connected to the material box 2. A discharge pipe 4 is provided at the bottom of the material box 2. Combination Figure 4 and Figure 5 One end of the discharge pipe 4 has an inlet connected to the material box 2, and the other end has an outlet 43; the cross-sectional area of ​​the discharge pipe 4 continuously decreases from the inlet to the outlet 43; the cross-sectional shape of the outlet 43 is similar to the cross-sectional shape of the material sheet 100; combined with Figure 6 The discharge pipe 4 of the present invention is configured to guide the material sheet 100 so that it flows out from the discharge nozzle 43 in a specific orientation.

[0020] As one embodiment, the material sheet 100 of the present invention is rectangular, and the cross-sectional shape of the discharge nozzle 43 is similar to the cross-sectional shape of the material sheet 100 in the length direction; this ensures that the material sheet 100 flows out of the discharge nozzle 43 in the length direction.

[0021] In one embodiment, a vibrator 41 is installed on the material bin 2, abutting against the discharge pipe 4. The vibrator 41 generates an excitation force, and the horizontally oriented material sheet 100, guided by the channel inside the pipe and under the action of the excitation force, changes its orientation to vertical, and then flows out from the discharge nozzle 43, preventing the material sheet 100 from accumulating in the discharge pipe 4. Under the action of the excitation force, the vertically oriented material sheet 100 can flow rapidly in the channel inside the pipe, increasing the feeding speed.

[0022] Furthermore, the vibrator 41 is an ultrasonic vibrator with a high vibration frequency and small amplitude, which can quickly realize the reversal and flow of the material sheet 100.

[0023] Even better, a mounting bracket 42 is fixed on the material box 2, and the vibrator 41 is fixed on the mounting bracket 42.

[0024] Furthermore, the material box 2 is provided with a feeding port 21 for pre-filling the material sheet 100.

[0025] As one embodiment, a longitudinal rail 134 that slides and engages with a longitudinal sliding sleeve 133 is fixed on the longitudinal beam 13, and a transverse rail 144 that slides and engages with a transverse sliding sleeve 143 is fixed on the transverse beam 14.

[0026] In one embodiment, the molding die 3 is located below the material box 2 and has multiple longitudinal grooves 31 and transverse grooves 32; the longitudinal motor 132 and the transverse motor 142 are activated so that the discharge pipe 4 is located at one end of a longitudinal groove 31; then the longitudinal motor 132 is activated so that the transverse beam 14 moves along the longitudinal beam 13, and the material sheet 100 flows out from the discharge nozzle 43 and continuously enters the longitudinal groove 31.

[0027] After the material is laid in one longitudinal groove 31, the transverse motor 142 moves to position the discharge pipe 4 at one end of another longitudinal groove 31, and repeats the aforementioned action.

[0028] After the material is laid in the longitudinal groove 31, the longitudinal movement motor 132 and the transverse movement motor 142 are activated, positioning the discharge pipe 4 at one end of a transverse groove 32. The reversing motor 22 then rotates the discharge pipe 4 90°, repeating the aforementioned material laying action.

[0029] Since the material sheets 100 flowing out from the discharge nozzle 43 are oriented in the same direction, the fibers are oriented in the same way after molding, resulting in the molded product having better mechanical properties.

[0030] As one embodiment, the frame body 1 has a clearance notch 10 on one side; slide rails can be symmetrically arranged on both sides of the molding mold 3, and the frame body 1 is placed on the slide rails. During material feeding, the frame body 1 slides to the top of the molding mold 3, and after material feeding is completed, it slides to one side of the molding mold 3 without interfering with the molding operation. The material feeding process is convenient and has high positional accuracy.

[0031] As an embodiment, two vertical beams are provided on both sides of the frame body, and a vertical moving plate is slidably mounted on the two vertical beams on the same side; both ends of the longitudinal beam are fixedly arranged on the corresponding vertical moving plate on one side; the two vertical moving plates can slide synchronously along the vertical beams to finely adjust the height of the discharge nozzle, so that it is at the optimal feeding position. When the frame body moves, the discharge nozzle can be raised to avoid collision with the forming mold.

[0032] Further, in combination with Figure 7 , the tops of the two vertical beams on the same side are connected with a reinforcing beam, and a vertical moving electric cylinder is mounted on the reinforcing beam; a horizontally arranged fixing plate is fixedly arranged on the vertical moving plate, and the vertical moving electric cylinder is connected to the fixing plate; the two vertical moving electric cylinders act synchronously to precisely adjust the height of the discharge nozzle. Preferably, a vertical rail in sliding fit with the vertical moving plate is fixedly arranged on the vertical beam.

[0033] According to the chopped fiber sheet discharging device for compression molding of the present invention, the shape of the discharge nozzle of the discharge pipe makes all the discharged material sheets face the same direction. After molding, the fibers of the product are oriented uniformly, and the product has good mechanical properties.

[0034] Optionally, the material sheet of the present invention is a chopped prepreg sheet.

[0035] As an embodiment, a material poking device is provided at the connection position between the material box and the discharge pipe, and a material poking motor for driving the material poking device to rotate is arranged outside the material box.

[0036] Optionally, the material poking device comprises a rotating shaft in transmission connection with the material poking motor, and a plurality of material poking claws are annularly arranged on the rotating shaft; the speed of the rotating shaft is controlled, so as to control the feeding amount and feeding speed in the discharge pipe.

[0037] The present invention provides a fiber orientation control method based on the discharging device, comprising the following steps: S1, loading the material sheets into the material box; actuating the longitudinal moving motor and the transverse moving motor to move the transverse sliding sleeve to the feeding position, so that the discharge nozzle is located directly above one end of a longitudinal groove of the forming mold, which is the feeding start point; Further, the material sheet has a length l, a width w, and a thickness t; the width of the discharge nozzle satisfies: w<w0<l; so that the material sheet flows out from the discharge nozzle along the length direction. The height of the discharge nozzle satisfies: t<t0<w; so as to prevent the material sheet from deflecting in the thickness direction.

[0038] The height of the discharge nozzle 43 from the material drop position is: H=k*l, where k ranges from 0.5 to 2, to prevent the material piece 100 from changing its posture during the fall.

[0039] S2, set the rotation speed of the feeder 23 so that the flow rate of the material sheet 100 is q. m ; S3, start the vibrator 41 and adjust its vibration frequency to 20 ~ 40 kHz and amplitude to 0.05 ~ 0.15 mm; S4, the discharge nozzle 43 continuously feeds from the feeding start point to the feeding end point, completing the feeding of the longitudinal trough 31; Control the travel speed v of hopper 2 m =L*q m / M; where L is the feeding stroke of the discharge nozzle 43, and M is the total mass of the added material piece 100; S5, repeat steps S1 to S4 to complete the feeding of other longitudinal troughs 31; S6, the reversing motor 22 is activated to rotate the direction of the discharge nozzle 43 by 90°, and the steps of S1~S4 are repeated to complete the feeding of the transverse trough 32.

[0040] In summary, this invention provides a device for discharging chopped fiber sheets during molding. The sheet 100 is guided by a discharge pipe 4, and the shape of the discharge nozzle 43 ensures that the outflowing sheet 100 faces the same direction. After molding, the product exhibits consistent fiber orientation and good mechanical properties. This invention also provides a method for controlling fiber orientation.

[0041] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A device for discharging molded short-cut fiber sheets, characterized in that, comprising a frame body, two longitudinal beams are erected on the frame body; a transverse beam is arranged between the two longitudinal beams, two ends of the transverse beam are respectively fixedly connected with a longitudinal movement sliding sleeve, and the longitudinal movement sliding sleeves are slidably sleeved on the longitudinal beam on the corresponding side; the frame body is further rotatably erected with a longitudinal movement lead screw which is parallel to the longitudinal beams and is in threaded penetration connection with the longitudinal movement sliding sleeves; the frame body is further provided with a longitudinal movement motor in transmission connection with the longitudinal movement lead screw; the transverse beam is slidably sleeved with a transverse movement sliding sleeve, and the frame body is further rotatably erected with a transverse movement lead screw which is parallel to the transverse beam and is in threaded penetration connection with the transverse movement sliding sleeve; the frame body is further provided with a transverse movement motor in transmission connection with the transverse movement lead screw; a reversing motor is fixedly arranged on the transverse movement sliding sleeve, the reversing motor is in transmission connection with a material box, and a discharging pipe is arranged at the bottom of the material box; one end of the discharging pipe is provided with a feeding port connected with the material box, and the other end is provided with a discharging nozzle; from the feeding port to the discharging nozzle, the cross-sectional area of the discharging pipe is continuously reduced; the cross-sectional shape of the discharging nozzle is contoured to the cross-sectional shape of the material sheet; the discharging pipe is configured to guide the material sheet so that it flows out from the discharging nozzle in a specific orientation.

2. The device for discharging molded short-cut fiber sheets as described in claim 1, characterized in that, the material sheet is rectangular, and the cross-sectional shape of the discharging nozzle is contoured to the cross-sectional shape of the material sheet in the length direction.

3. The device for discharging molded short-fiber sheets as described in claim 1, characterized in that, longitudinal rails in sliding fit with the longitudinal movement sliding sleeves are fixedly arranged on the longitudinal beams, and transverse rails in sliding fit with the transverse movement sliding sleeve are fixedly arranged on the transverse beam.

4. The device for discharging molded short-fiber sheets as described in claim 1, characterized in that, one side of the frame body is provided with an avoiding notch.

5. The device for discharging molded short-cut fiber sheets as described in claim 1, characterized in that, two vertical beams are arranged on both sides of the frame body, and a vertical movement plate is slidably mounted on the two vertical beams located on the same side; two ends of the longitudinal beam are fixedly arranged on the vertical movement plate on the corresponding side.

6. The device for discharging molded short-cut fiber sheets as described in claim 5, characterized in that, the tops of the two vertical beams located on the same side are connected with a reinforcing beam, and a vertical movement electric cylinder is mounted on the reinforcing beam; a horizontally arranged fixing plate is fixedly arranged on the vertical movement plate, and the vertical movement electric cylinder is connected with the fixing plate.

7. The device for discharging molded short-fiber sheets as described in any one of claims 1 to 6, characterized in that, the material box is provided with a feeding port, and a vibrator abutting against the discharging pipe is mounted on the material box; a material poking device is arranged at the connection position of the material box and the discharging pipe, and a material poking motor for driving the material poking device to rotate is arranged outside the material box.

8. The device for discharging molded short-cut fiber sheets as described in claim 7, characterized in that, the vibrator is an ultrasonic vibrator; a mounting frame is fixedly arranged on the material box, and the vibrator is fixed on the mounting frame.

9. A fiber orientation control method based on the emission device as described in claim 7, characterized in that, comprising the following steps: S1, loading material sheets into the material box; the longitudinal movement motor and the transverse movement motor act to move the transverse movement sliding sleeve to a feeding position, so that the discharging nozzle is located directly above one end of a longitudinal groove of a forming mold, which serves as a feeding starting point; S2, Set the rotation speed of the feeder so that the flow rate of the material sheet is q. m ; S3, starting the vibrator, and adjusting the vibration frequency thereof to 20 ~ 40 kHz and the amplitude thereof to 0.05 ~ 0.15 mm; S4, the discharging nozzle travels from the feeding starting point to a feeding end point for continuous feeding, so as to complete the feeding of this longitudinal groove; Control the travel speed v of the hopper m =L*q m / M; where L is the feeding stroke of the nozzle and M is the total mass of the added material; S5, repeating the steps S1 to S4 to complete the feeding of other longitudinal grooves; S6, the reversing motor acts to rotate the orientation of the discharging nozzle by 90°, and the steps S1 to S4 are repeated to complete the feeding of the transverse grooves.

10. The fiber orientation control method as described in claim 9, characterized in that, the material sheet has a length of l, a width of w and a thickness of t; the width of the discharging nozzle satisfies: w<w0<l; the height of the discharging nozzle satisfies: t<t0<w; the height of the discharging nozzle from the material dropping position satisfies: H=k*l, wherein the range of k is 0.5~2.

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