A method for forming a spatial three-dimensional truss

Abstract

The present invention provides a method for forming a three-dimensional spatial truss, comprising the following steps: Step 1: Using a fiber-reinforced thermoplastic resin-based composite material prepreg as a raw material, heating and softening it in a shaping mold, and forming it into a truss longitudinal beam structure under the action of roller extrusion; Step 2: Winding the prepreg material onto the outer surfaces of multiple longitudinal beams through a winding mechanism, welding the intersection of the horizontal and longitudinal beams through roller heating to form a truss structure; Step 3: Simultaneously, the longitudinal beams are pulled by a different speed adjustment device to continuously move the longitudinal beams, making the above forming process sustainable, thereby producing a truss of infinite length. During the forming process, the truss is adjusted by adjusting the pulling speed of different longitudinal beams to obtain different bending angles and bending directions, thereby obtaining a spatial three-dimensional truss structure. The present invention achieves different bending angles and bending directions of the truss by regulating the pulling speed of different longitudinal beams in the truss, thereby realizing the formation of a spatial three-dimensional truss structure.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing, and in particular to a spatial three-dimensional truss forming method for realizing the forming of a complex curvature truss structure. Background Art

[0002] Currently, composite truss structures are often formed using mold-assisted manual layup. This presents challenges such as high costs, long construction times, limited processing options, long production cycles, and poor quality uniformity. Truss forming equipment can only produce simple, one-dimensional, linear truss structures, making it difficult to meet the demands of complex curvature truss structures.

[0003] Fiber-reinforced resin-based composites, with their advantages of low weight, high strength, and ease of forming, have been widely used in the aerospace field. Composite truss structures, combining the advantages of lightweight materials and high strength, are widely favored in the aerospace field and have become a key development trend in the future. Summary of the Invention

[0004] To solve the above problems, the present invention discloses a three-dimensional forming method for a spatial truss. By regulating the pulling speed of different longitudinal beams in the truss, different bending angles and bending directions of the truss are obtained, thereby realizing the forming of a spatial three-dimensional truss structure.

[0005] A three-dimensional forming method for a space truss comprises the following steps:

[0006] Step 1: Using fiber-reinforced thermoplastic resin composite material prepreg as raw material, it is heated and softened in a shaping mold and formed into a truss longitudinal beam structure under the action of roller extrusion;

[0007] Step 2: Wrap the prepreg around the outer surface of multiple longitudinal beams through a winding mechanism, and weld the intersection of the transverse and longitudinal beams through roller heating to form a truss structure;

[0008] Step 3: At the same time, the longitudinal beams are pulled by the different speed adjustment device to continuously move the longitudinal beams, so that the above forming process can be sustainable, thereby producing a truss of infinite length. During the forming process, the truss can obtain different bending angles and bending directions by adjusting the pulling speed of different longitudinal beams, thereby obtaining a spatial three-dimensional truss structure.

[0009] Furthermore, the longitudinal beam traction speed adjustment device includes a speed-varying traction transmission mechanism, a clamping device and a clamping mechanism arranged on the traction mechanism mounting plate; the clamping device includes a clamping core shaft, the clamping core shaft is coaxially installed with the longitudinal beam forming mold, and is evenly provided with mounting grooves in three directions, wherein a plurality of driven rollers are arranged in sequence from top to bottom in the mounting grooves; a driving wheel mounting frame is provided in the direction corresponding to each mounting groove; a plurality of driving rollers adapted to the driven rollers are arranged on the driving wheel mounting frame from top to bottom; a transmission gear is installed at one end of each driving roller; wherein every two adjacent transmission gears are meshed with each other; the speed-varying traction transmission mechanism includes a stepping motor, a reduction motor and a coupling; wherein the stepping motor is connected to the coupling through the reduction motor; the coupling is connected to one of the driving rollers; wherein the rear side of the driving wheel mounting frame is connected to the clamping mechanism.

[0010] Furthermore, the clamping mechanism includes an adjustment frame, a positioning pin and a clamping and tightening knob; wherein each end of the driving wheel mounting frame is inserted into the limiting hole of the adjustment frame through the positioning pin; wherein one end of the clamping and tightening knob passes through the adjustment frame and is tightened on the driving wheel mounting frame.

[0011] Furthermore, the lower portion of the clamping core shaft is a hollow structure.

[0012] Furthermore, the method for adjusting the speed of longitudinal beam traction is as follows: the truss is driven by friction between the rubber wheel and the truss surface, and the rubber wheel rotates to continuously pull the truss; each rubber wheel corresponds to a longitudinal beam, and when the speeds of the three rubber wheels are the same, the three longitudinal beams are formed at the same speed, and the produced truss is a one-dimensional linear truss in space; when the speeds of the three rubber wheels are different, the three longitudinal beams are formed at different speeds, and the produced truss is a three-dimensional truss structure in space; specifically: the active roller groups on the three groups of active wheel mounting frames are group A, group B and group C, wherein the active rollers are rubber wheels, wherein the linear speed adjustment range of the rubber wheels is 1cm / min-30cm / min, and the magnitude of the friction force is regulated by adjusting the clamping force, and the adjustment range of the friction force is 1.5N-80N.

[0013] Furthermore, when the friction force is 80N, the traction speed of groups A\B is v1, in cm / min, and the traction speed of group C is v2≤v1+0.2pi / t, where t is the forming time, in min; when the friction force is less than 80N, the traction speed of structure C is v2≤(1+α)(v1+0.2pi / t), where α is the sliding factor, and its value is related to the clamping force and roller material.

[0014] Furthermore, the method for adjusting the speed of longitudinal beam traction is as follows: the truss is driven by friction between the rubber wheel and the truss surface, and the rubber wheel rotates to continuously pull the truss; each rubber wheel corresponds to a longitudinal beam, and when the speeds of the three rubber wheels are the same, the three longitudinal beams are formed at the same speed, and the produced truss is a one-dimensional linear truss in space; when the speeds of the three rubber wheels are different, the three longitudinal beams are formed at different speeds, and the produced truss is a three-dimensional truss structure in space; specifically: the active roller groups on the three groups of active wheel mounting frames are group A, group B and group C, wherein the active rollers are rubber wheels, wherein the linear speed adjustment range of the rubber wheels is 1cm / min-30cm / min, and the magnitude of the friction force is regulated by adjusting the clamping force, and the adjustment range of the friction force is 1.5N-80N.

[0015] Furthermore, when the friction force is 80N, the traction speed of groups A\B is v1, in cm / min, and the traction speed of group C is v2≤v1+0.2pi / t, where t is the forming time, in min; when the friction force is less than 80N, the traction speed of structure C is v2≤(1+α)(v1+0.2pi / t), where α is the sliding factor, and its value is related to the clamping force and roller material.

[0016] Beneficial effects of the present invention:

[0017] 1. The clamping mandrel is coaxially mounted with the stringer forming mold, and three rollers are installed in three directions to support the stringer. The lower portion of the clamping mandrel is hollowed out to minimize contact with the stringer mold, reducing heat transfer and preventing overheating of the traction structure. Traction power is provided by a 42mm stepper motor, which transmits it to the intermediate gear via a reducer and coupling. The intermediate gear transmits power to the upper and lower gears via idler gears, respectively, enabling all three gears to rotate in the same direction. Each gear drives a roller, which contacts the outer surface of the truss, generating friction, which pulls the stringer upward. This friction is adjusted by the roller material and the clamping mechanism.

[0018] 2. It solves the problems of weak bonding of the horizontal and vertical beams of the composite truss, poor overall stiffness of the truss, and poor design of the truss structure, and can improve the forming quality and forming efficiency of the truss structure.

[0019] 3. A forming method for a spatial truss structure is proposed. By regulating the forming speed of different longitudinal beams of the truss, a spatial three-dimensional truss structure with different bending directions and bending angles is obtained. Compared with the technical method of producing one-dimensional trusses and then welding them twice, this method reduces the process and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 , the longitudinal beam traction speed adjustment device of the present invention;

[0021] Figure 2, the three-dimensional truss structure 1 processed and formed in this embodiment.

[0022] Figure 3 , the processed and formed truss three-dimensional structure 2 of this embodiment.

[0023] List of reference numerals:

[0024] Among them, 1-driving roller; 2-driven roller; 3-clamping mandrel; 4-driving wheel mounting frame; 5-transmission gear; 6-traction mechanism mounting plate; 7-reduction motor; 8-stepping motor; 9-coupling; 10-clamping and tightening knob; 11-locating pin; 12-adjustment frame. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inward" and "outward" refer to directions toward or away from the geometric center of a particular component, respectively.

[0026] A three-dimensional forming method of a space truss in this embodiment includes the following steps:

[0027] Step 1: Using fiber-reinforced thermoplastic resin composite material prepreg as raw material, it is heated and softened in a shaping mold and formed into a truss longitudinal beam structure under the action of roller extrusion;

[0028] Step 2: Wrap the prepreg around the outer surface of multiple longitudinal beams through a winding mechanism, and weld the intersection of the transverse and longitudinal beams through roller heating to form a truss structure;

[0029] Step 3: At the same time, the longitudinal beams are pulled by the different speed adjustment device to continuously move the longitudinal beams, so that the above forming process can be sustainable, thereby producing a truss of infinite length. During the forming process, the truss can obtain different bending angles and bending directions by adjusting the pulling speed of different longitudinal beams, thereby obtaining a spatial three-dimensional truss structure.

[0030] like Figure 1As shown, the longitudinal beam traction speed regulating device includes a speed-varying traction transmission mechanism, a clamping device and a clamping mechanism arranged on a traction mechanism mounting plate 6; the clamping device includes a clamping core shaft 3, which is coaxially mounted with the longitudinal beam forming mold and is evenly provided with mounting grooves in three directions, wherein a plurality of driven rollers 2 are sequentially arranged in the mounting grooves from top to bottom; wherein a driving wheel mounting frame 4 is provided in the direction corresponding to each mounting groove; and a plurality of driving rollers 1 adapted to the driven rollers 2 are sequentially provided on the driving wheel mounting frame 4 from top to bottom; a transmission gear 5 is installed at one end of each driving roller 1; wherein every two adjacent transmission gears 5 are meshed with each other; the speed-varying traction transmission The mechanism includes a stepper motor 8, a reduction motor 7 and a coupling 9; wherein the stepper motor 8 is connected to the coupling 9 through the reduction motor 7; the coupling 9 is connected to one of the driving rollers 1; wherein the rear side of the driving wheel mounting frame 4 is connected with a clamping mechanism; the clamping mechanism includes an adjusting frame 12, a positioning pin 11 and a clamping and tightening knob 10; wherein each end of the driving wheel mounting frame 4 is inserted into the limiting hole of the adjusting frame 12 through the positioning pin 11; wherein one end of the clamping and tightening knob 10 passes through the adjusting frame 12 and is tightened on the driving wheel mounting frame 4; the lower part of the clamping mandrel 3 is a hollow structure; the lower part of the clamping mandrel is a hollow structure, which reduces the contact area with the longitudinal beam mold to reduce heat transfer.

[0031] In this embodiment, traction power is provided by a 42-inch stepper motor, which transmits it to an intermediate gear via a reducer and coupling. The intermediate gear then transmits power to the upper and lower gears via an idler gear, enabling all three gears to rotate in the same direction. Each gear drives a roller, which creates friction with the outer surface of the truss, pulling the longitudinal beam upward. This friction is adjusted by the roller material and the clamping mechanism.

[0032] The truss is a triangular prism structure consisting of three longitudinal beams and multiple transverse beams. The longitudinal beams are formed through a pultrusion process, and the forming speed of each beam can be controlled by adjusting the pulling speed. The three longitudinal beams are named A, B, and C. The transverse beam winding speed remains constant throughout the forming process.

[0033] Implementation Plan 1: First, set the pulling speed of longitudinal beams A and B to 10 cm / min, and the pulling speed of longitudinal beam C to 9 cm / min. After 5 minutes of forming, the truss structure will bend in the direction of C to form a two-dimensional truss structure; set the pulling speed of longitudinal beams A and C to 10 cm / min, and the pulling speed of longitudinal beam B to 9 cm / min. After 5 minutes of forming, the truss structure will bend in the direction of B again to form a three-dimensional truss structure, such as Figure 2 shown.

[0034] Implementation Plan 2: Set the pulling speed of longitudinal beam A to 10cm / min, the pulling speed of longitudinal beam B to 9.5cm / min, and the pulling speed of longitudinal beam C to 9cm / min. After the forming process begins, the truss will directly form a spiral three-dimensional truss structure, such as Figure 3 shown.

[0035] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above-mentioned embodiment, but also include technical solutions composed of any combination of the above technical features.

Claims

1. A three-dimensional forming method for a spatial truss, characterized by: The method comprises the following steps: Step 1: Using fiber-reinforced thermoplastic resin composite material prepreg as raw material, it is heated and softened in a shaping mold and formed into a truss longitudinal beam structure under the action of roller extrusion; Step 2: Wrap the prepreg around the outer surface of multiple longitudinal beams through a winding mechanism, and weld the intersection of the transverse and longitudinal beams through roller heating to form a truss structure; Step 3: At the same time, the longitudinal beam is pulled by the speed regulating device to continuously move the longitudinal beam, so that the above forming process can be sustained, thereby producing a truss of infinite length. During the forming process, the truss is adjusted to obtain different bending angles and bending directions by adjusting the pulling speed of different longitudinal beams, thereby obtaining a spatial three-dimensional truss structure; the longitudinal beam pulling speed regulating device includes a speed traction transmission mechanism, a clamping device and a clamping mechanism arranged on a traction mechanism mounting plate (6); the clamping device includes a clamping mandrel (3), the clamping mandrel (3) is coaxially installed with the longitudinal beam forming mold, and Mounting slots are evenly arranged in three directions, wherein a plurality of driven rollers (2) are arranged in the mounting slots in sequence from top to bottom; a driving wheel mounting frame (4) is arranged in the direction corresponding to each mounting slot; a plurality of driving rollers (1) adapted to the driven rollers (2) are arranged in sequence from top to bottom on the driving wheel mounting frame (4); a transmission gear (5) is mounted on one end of each driving roller (1); wherein every two adjacent transmission gears (5) are meshed with each other; a different speed traction transmission mechanism comprises a stepping motor (8), a reduction motor (7) and a coupling (9); wherein the stepper motor (8) is connected to the coupling (9) through the reduction motor (7); the coupling (9) is connected to one of the active rollers (1); wherein the rear side of the active wheel mounting frame (4) is connected to a clamping mechanism; the method for adjusting the speed of the longitudinal beam traction is as follows: the truss is driven by friction between the rubber wheel and the truss surface, and the rubber wheel rotates so that the truss is continuously pulled; each rubber wheel corresponds to a longitudinal beam, and when the speeds of the three rubber wheels are the same, the three longitudinal beams are formed at the same speed, and the produced truss is a spatial one-dimensional linear truss; when the speeds of the three rubber wheels are different At the same time, the forming speeds of the three longitudinal beams are different, and the truss produced is a spatial three-dimensional truss structure; specifically: the active roller groups on the three groups of active wheel mounting frames (4) are group A, group B and group C respectively, wherein the active rollers are rubber wheels, wherein the rubber wheel linear speed adjustment range is 1cm / min-30cm / min, and the friction force is regulated by adjusting the clamping force, and the adjustment range of the friction force is 1.5N-80N; when the friction force is 80N, the traction speed of group A\B is v1, in cm / min, and the traction speed of group C is v2 ≤v1+0.2pi / t, wherein t is the forming time, in min; when the friction force is less than 80N, the traction speed of structure C is v2 ≤(1+α)(v1+0.2pi / t), α is the sliding factor, and the value is related to the clamping force and the roller material.

2. The method for three-dimensionally forming a spatial truss according to claim 1, characterized in that: The clamping mechanism comprises an adjustment frame (12), a positioning pin (11) and a clamping and tightening knob (10); wherein each end of the driving wheel mounting frame (4) is inserted into a limiting hole of the adjustment frame (12) through the positioning pin (11); wherein one end of the clamping and tightening knob (10) passes through the adjustment frame (12) and is screwed onto the driving wheel mounting frame (4).

3. The method for three-dimensionally forming a spatial truss according to claim 1, wherein: The lower part of the clamping core shaft (3) is a hollow structure.

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