Production method and equipment for a composite material circular tube

Abstract

A method and equipment for producing composite material round tubes, including an alloy smelting device, a centerless lathe, a yarn rack, a pultrusion assembly, a tractor and a cutting machine arranged in sequence, the alloy smelting device is used to smelt low-melting-point alloys and is connected to an extrusion die at the same time, extrusion molding to obtain continuous low-melting-point alloy mold cores, the centerless lathe is used to process and straighten the low-melting-point alloy mold cores, the pultrusion assembly is used to solidify and mold composite material round rods; the tractor pulls the composite material round rods to move, and the composite material round rods are cut according to size after leaving the tractor and entering the cutting machine, and finally put into the alloy smelting device to heat and melt the mold core, and the finished composite material round tube can be obtained after cleaning. The present invention overcomes the problems of limited and fixed mold core length, sagging of the mold core in the pultrusion die, uneven wall thickness of the round tube, and flattening of the composite material round tube by the tractor in the traditional pultrusion equipment, greatly improves the dimensional accuracy of the round tube, and is particularly suitable for producing high-precision pultrusion round tubes.

Description

Technical Field

[0001] The present invention relates to the field of composite material pultrusion winding molding, and more specifically to a production method and equipment for a composite material circular tube with a low melting point alloy as a mandrel. Background Art

[0002] In the production process of a composite material pultruded and wound circular tube, one end of the mandrel is usually fixed. After the fibers are impregnated with resin, they are fixed on the surface of the mandrel. Then, the fibers and the mandrel enter the mold together, and the circular tube is obtained by curing and forming. After the circular tube leaves the mold, the mandrel is separated, and the inside of the circular rod becomes hollow. When using a traction device to traction the circular tube, it is then cut into the required length.

[0003] Since only one side of the mandrel is fixed and the other side is completely suspended inside the outer mold, affected by gravity, the mandrel is bound to sag inside the outer mold, thus affecting the concentricity of the pultruded circular tube, resulting in uneven distribution of fibers in the circumferential direction of the circular tube, and further causing a decrease in the straightness of the circular tube.

[0004] During the traction process, it is often difficult to control the clamping force on the circular tube of the traction device. If the clamping force is too small, the circular tube cannot be tractioned; if the clamping force is too large, the clamped part of the circular tube will be deformed; some devices use a belt-type traction machine to clamp the entire composite material circular tube. If the circular tube is clamped and deformed, all the products produced can only be scrapped; there is also a part of the traction machine that only fixes and clamps a certain position of the circular tube, and then drives the circular tube forward. After reaching the end of the stroke, it resets and clamps a certain section to move forward again. This method only clamps the fixed position of the circular tube, but the clamped part of the circular tube will still be deformed. At this time, only the clamped part can be cut off, and a large amount of waste is still generated during the production process.

[0005] If the mandrel moves with the circular tube throughout the process, the problems of the mandrel sagging inside the outer mold and the traction machine squeezing the circular tube can be effectively avoided. After cutting, the mandrel is removed. Since using a common metal material as a movable mandrel has a high cost and is not easy to demold; the present invention uses a low melting point alloy as the mandrel, which can effectively avoid the above problems. The low melting point alloy can effectively avoid the demolding process. It only needs to reheat and melt the obtained circular rod to remove the low melting point alloy. It should be noted that the melting temperature of the low melting point alloy is higher than the resin forming temperature of the circular tube and lower than the thermal deformation temperature of the circular tube. At the same time, the melting process of the low melting point alloy also serves as the annealing process of the circular tube. Using a low melting point alloy as the mandrel can effectively improve the accuracy of various parameters of the circular tube. The low melting point alloy can be recycled during the production process, and no waste is generated during the production process. Compared with the traditional mandrel, it is clean and environmentally friendly and is suitable for the production of high-precision pultruded and wound circular tubes. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a production method and equipment for a composite material circular tube.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A method for producing a composite material round tube comprises the following steps:

[0009] Choose low melting point alloy as the core material;

[0010] Adding a low melting point alloy into an alloy smelting furnace, heating the low melting point alloy to melt the low melting point alloy to form a liquid low melting point alloy fluid;

[0011] The liquid low melting point alloy fluid is extruded through an extrusion device, and then cooled to obtain a low melting point alloy mold core;

[0012] The low melting point alloy mold core is sent to the centerless lathe to be processed and calibrated to the required size and accuracy;

[0013] Pultrusion treatment, winding the yarn pre-impregnated with resin on the surface of the low-melting-point alloy mold core, firstly winding the inner layer yarn on the circumferential surface of the low-melting-point alloy mold core along the longitudinal direction to form an inner layer spiral structure, then using the winding yarn to wind on the inner layer structure formed by the inner layer yarn to form a middle layer winding structure, and then arranging the outer layer yarn on the middle layer winding structure, and the outer layer yarn is wound around the circumferential surface along the longitudinal direction of the low-melting-point alloy mold core to form an outer layer structure, thereby forming a structure with three layers of inner layer, middle layer and outer layer on the surface of the low-melting-point alloy mold core, and then feeding it into the corresponding mold, and the low-melting-point alloy mold core always follows the movement of the pre-impregnated yarn during the pultrusion process;

[0014] The resin on the yarn is solidified to form an outer protective layer by heating and curing in the mold. The winding of the yarn and the curing of the resin make the space between the low-melting-point alloy mold core and the outer protective layer a solid structure, thereby obtaining a composite material round rod with a solid structure.

[0015] The composite material round rod of the solid structure is pulled to the cutting machine by a traction machine and cut according to the required length;

[0016] The cut composite material round rod is then placed in an alloy smelting furnace and heated to melt the low melting point alloy core inside the composite material round rod. The composite material round rod is then taken out and washed with water to obtain a finished composite material round rod. The melted low melting point alloy is recycled again.

[0017] The melting temperature of the low melting point alloy is lower than the thermal deformation temperature of the finished composite material round rod and higher than the resin curing molding temperature on the composite material round rod, so that the low melting point alloy mold core will not be melted when the resin is cured.

[0018] When the composite material round tube is washed with water, ultrasonic cleaning is adopted.

[0019] A production device for a composite material round tube, comprising a sequentially arranged alloy smelting device, a centerless lathe, a yarn rack, a drawing and winding assembly, a tractor and a cutting machine;

[0020] The alloy smelting device includes an alloy smelting furnace and an alloy extrusion device, which are used to melt the core inside the composite material round rod for repeated recycling, and at the same time extrude the low-melting-point alloy core. The core inside the composite material round rod is a low-melting-point alloy core;

[0021] The centerless lathe is installed in the downstream area of the alloy smelting device and is used to process and calibrate the low-melting-point alloy core to the required size and accuracy;

[0022] The yarn rack is installed in the downstream area of the centerless lathe and is used to place yarn bobbins, with a space left in the middle to provide space for the movement of the low-melting-point alloy;

[0023] The drawing and winding assembly is installed in the downstream area of the yarn rack and is used to draw and wind the yarn on the surface of the low-melting-point alloy core, so that an outer protective layer is formed on the surface of the low-melting-point alloy core, and then the low-melting-point alloy core enters the mold for solidification and molding to obtain a solid composite material round rod;

[0024] The tractor is installed in the downstream area of the drawing and winding assembly and is used to pull the extruded composite material round rod;

[0025] The cutting machine is installed in the downstream area of the tractor and cuts off the composite material round rod led out from the tractor.

[0026] The alloy smelting furnace includes a furnace body, which is made of a material that does not react with the low-melting-point alloy. The furnace body is filled with a heating liquid that does not react with the low-melting-point alloy and the composite material round rod. A heating component and a round rod placement rack are provided in the furnace body. The round rod placement rack is used to place the composite material round rod and completely immerse the composite material round rod in the heating liquid. A horizontal plate is provided at the upper end of the furnace body. The round rod placement rack is connected to the horizontal plate through a lifting rod. The density of the heating liquid is less than the density of the low-melting-point alloy.

[0027] The alloy extrusion device includes a cleaning outlet and an extrusion outlet respectively arranged on both sides of the furnace body, and the extrusion outlet is higher than the cleaning outlet. The extrusion outlet is connected to a bent pipe, and the bent pipe is connected to an extrusion die cavity. There is a screw rod inside the extrusion die cavity. The screw rod is connected to a screw motor. The screw rod is used to guide the liquid low-melting-point alloy for extrusion molding. An extrusion head is fixed at one end of the extrusion die cavity. An extrusion die is fixed on the extrusion head. The extrusion head is connected to a cooling device. The cooling device is used to cool the extruded low-melting-point alloy. Switch control valves are provided in both the cleaning outlet and the extrusion outlet to control opening and closing.

[0028] The turning center of the centerless lathe is concentrically arranged with the extrusion die. After the low-melting-point alloy die core comes out of the alloy smelting device, it enters the centerless lathe. The centerless lathe turns the low-melting-point alloy die core to the standard size and then enters the winding and wrapping assembly.

[0029] The winding and wrapping assembly includes a winding and wrapping fixed frame. A vertical plate is fixed on the winding and wrapping fixed frame. A yarn-passing cylinder is fixed on the vertical plate. A die core hole is provided on the yarn-passing cylinder. The low-melting-point alloy die core passes through the center of the yarn-passing cylinder. There are hole positions for passing yarn around the die core hole of the yarn-passing cylinder. A rotatable turntable is installed on the other side of the vertical plate. A winding yarn cylinder is fixed on the turntable. The winding yarn cylinder is used to place winding yarn. The turntable is connected to a motor arranged at the bottom of the winding and wrapping fixed frame through a belt. There is a pre-impregnation tank filled with resin on the vertical plate. A yarn-discharging plate is provided in the pre-impregnation tank. The outer layer yarn entering the pre-impregnation tank passes through the yarn-discharging plate to form pre-impregnation. The bottom of the pre-impregnation tank is connected to the yarn-passing cylinder through a diversion pipe. The resin filled in the pre-impregnation tank will enter the yarn-passing cylinder through the diversion pipe, so that both the inner layer yarn and the outer layer yarn have resin. After the low-melting-point alloy die core leaves the yarn-passing cylinder, the yarn coming out from the yarn-passing holes around the die core will closely adhere to the low-melting-point alloy die core. Then, the inner layer yarn is wound around the die core through the winding yarn, and then enters the die.

[0030] The die includes an upper heating die, a lower heating die and an outer die. The outer die is installed at the layered position of the upper heating die and the lower heating die. Heating rods are provided on both the upper heating die and the lower heating die to heat the outer die. A yarn-discharging device is provided at the front end of the outer die for passing through the outer layer yarn. The yarn-discharging device evenly arranges the outer layer yarn on the wound low-melting-point alloy die core. The arranged outer layer yarn and the wound low-melting-point alloy die core enter the outer die together. The resin on the low-melting-point alloy die core leaves the die after being cured in the outer die.

[0031] The tractor is a belt-type tractor.

[0032] The alloy smelting device, the centerless lathe, the yarn rack, the winding and wrapping assembly, the tractor and the cutting machine are arranged in a straight line.

[0033] The present invention uses a low-melting-point alloy as the core of a resin molding die; a continuous low-melting-point alloy round bar is obtained by metal extrusion molding, and after being processed and straightened, it enters a pultrusion winding device. During the pultrusion winding process, the core always moves with the pre-impregnated fiber. After winding and forming, heating and curing, the composite material round bar is cut according to the size after leaving the tractor, and then put back into the alloy smelting furnace to heat and melt the core. After cleaning, the finished product of the composite material round tube can be obtained. Due to the solid structure, the problem of the round tube being flattened due to too large clamping force of the tractor during the production of traditional round bars is overcome. At the same time, both ends of the core are traction-fixed, and the core is not easy to sag during the production process, affecting the circumferential fiber arrangement of the round tube, which can effectively improve the accuracy of various parameters of the round tube. The low-melting-point alloy can be recycled repeatedly during the production process, and no waste is generated during the production process. Compared with the traditional core, it is clean and environmentally friendly, and is especially suitable for the production of high-precision pultruded round tubes. The prepared composite material round tube is mainly used for crossbow arrows. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Appendix Figure 1 is a schematic structural diagram of the present invention;

[0035] Appendix Figure 2 is a schematic structural diagram of the alloy smelting device of the present invention;

[0036] Appendix Figure 3 is a schematic structural diagram of the pultrusion winding assembly of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] In order to further understand the features, technical means, specific purposes and functions achieved by the present invention, the present invention will be described in further detail below in conjunction with the drawings and specific embodiments.

[0038] As shown in the appendix Figures 1-3 The present invention provides a production method of a composite material round tube, including the following steps:

[0039] Select a low-melting-point alloy as the core material for preparing the core of the composite material round tube. Add the low-melting-point alloy into the alloy smelting furnace and heat it to melt the low-melting-point alloy to form a liquid low-melting-point alloy fluid. In addition to directly adding the low-melting-point alloy, the semi-finished product of the composite material round tube containing the low-melting-point alloy core just prepared can also be added into the alloy smelting furnace. Of course, the temperature in the alloy smelting furnace is just enough to melt the low-melting-point alloy without melting other parts of the composite material round tube.

[0040] Extrude the liquid low-melting-point alloy fluid through an extrusion device, and then cool it to obtain a low-melting-point alloy core. The extrusion device is a known device in the art. The cooling can be air cooling.

[0041] Feed the low-melting-point alloy core into a centerless lathe and machine and align the low-melting-point alloy core to the required dimensions and precision. The centerless lathe is also a well-known machining lathe. If the dimensions of the extruded low-melting-point alloy core do not meet the set requirements, machining can be carried out on the lathe at this time.

[0042] Pultrusion process: Wind the resin-preimpregnated yarns around the surface of the low-melting-point alloy core. First, wind the inner layer of yarn longitudinally along the circumferential surface of the low-melting-point alloy core to form an inner-layer spiral structure. Then, use the winding yarns to wind around the inner-layer structure formed by the inner layer of yarn to form a middle-layer winding structure. Next, arrange the outer layer of yarn on the middle-layer winding structure, and the outer layer of yarn winds along the longitudinal direction of the low-melting-point alloy core around the circumferential surface to form an outer-layer structure. Thus, a structure with a total of three layers, namely an inner layer, a middle layer, and an outer layer, is formed on the surface of the low-melting-point alloy core. Then, it is fed into the corresponding mold, and the low-melting-point alloy core always moves along with the preimpregnated yarns during the pultrusion process. A more specific form is that there are a total of three layers of yarns, namely the inner layer of yarn, the outer layer of yarn, and the winding yarns. First, wind the inner layer of yarn on the outer surface of the low-melting-point alloy core, then tighten it with the winding yarns, and then wind the outer layer of yarn. The three layers of yarns together form an outer protective layer. Since the three layers of yarns are already pre-impregnated with resin, the outer protective layer formed outside the low-melting-point alloy core is a resin protective layer.

[0043] Heat and cure in the mold to cure the resin on the yarns to form an outer protective layer. Combining the winding of the yarns and the curing of the resin makes the structure between the low-melting-point alloy core and the outer protective layer a solid structure, and a solid-structured composite material round rod is obtained. The resin curing temperature is lower than the melting temperature of the low-melting-point alloy core, thus ensuring the curing and forming of the resin, and at the same time not affecting the internal low-melting-point alloy core. Through curing, the three layers of yarns shrink and combine more tightly, thus forming a solid structure.

[0044] Since it is a solid structure, it is not easy to be flattened during the traction process. Use a tractor to traction the solid-structured composite material round rod to a cutting machine and cut it according to the required length to form sections of composite material round rods. At this time, it is still a semi-finished product because the internal low-melting-point core is still contained.

[0045] Put the cut composite material round rod back into the alloy smelting furnace, heat it up to melt the low-melting-point alloy core inside the composite material round rod, then take out the composite material round rod and wash it with ultrasonic water to obtain the finished composite material round rod, and the melted low-melting-point alloy is recycled again.

[0046] The melting temperature of the low-melting-point alloy is lower than the heat deformation temperature of the finished composite material round rod and higher than the resin curing and forming temperature of the composite material round rod, so that the low-melting-point alloy core will not melt during resin curing, and it will not affect the resin protective layer on the outer layer of the composite material when put back into the alloy smelting furnace.

[0047] Through the above processing method, a low-melting-point alloy is used as the core material of the mold, combined with the outer resin to form a solid structure. During the subsequent traction process, it will not be flattened due to the problem of being hollow, improving the preparation quality. Moreover, as the low-melting-point alloy core in the preparation process, it can be recycled repeatedly, saving costs.

[0048] During the entire preparation process, initially, a low-melting-point alloy is used for preparation. Subsequently, the preparation can be basically completed by using a composite material round tube semi-finished product that also includes a low-melting-point alloy core, without the need to continue adding low-melting-point alloy materials.

[0049] In addition, as shown in the appendix Figures 1-3 As shown, the present invention also provides a production device for a composite material round tube, including a sequentially arranged alloy smelting device 1, a centerless lathe 2, a yarn rack 3, a winding and pulling assembly 4, a tractor 5, and a cutting machine 6, which are arranged linearly as a whole to form a production line for preparing a composite material round tube.

[0050] The alloy smelting furnace 101 includes a furnace body 103, which is made of a material that will not react with the low-melting-point alloy and has a heat preservation function. For example, an inner sandwich layer can be provided on the side wall of the furnace body, or a heat preservation layer made of heat preservation material. The furnace body 103 contains a heating component. The furnace body 103 is fixed on a furnace body fixing plate 104. The heating component can be arranged on the furnace body fixing plate to heat from the bottom, or directly arranged inside the furnace body for heating. The lower part of the furnace body fixing plate 104 is connected to a furnace body fixing frame 105. The furnace body 103 contains a heating liquid 106, which will not react with the low-melting-point alloy and the composite material round rod. The density of the heating liquid 106 is less than the density of the low-melting-point alloy, so as to ensure that the low-melting-point alloy will sink in the heating liquid after being put into the furnace body, so that it can be fully heated and melted. The heating component can be a heating rod or a heating wire, which is heated after being powered on.

[0051] A cross plate 107 passing through the center of the upper end of the furnace body is installed on the furnace body 103. A round rod placement rack 108 is fixed at the center position of the cross bar 107. The round rod placement rack is connected to the cross plate by a lifting rod that can move up and down. The lifting rod can be threadedly connected to the cross plate, and only by rotating can the lifting movement be realized, or it has a corresponding buckle structure. Loosen the buckle structure to realize the lifting, and then close the buckle to fix the position after moving up and down to the corresponding position. The round rod placement rack 108 is used to place the cut composite material round rod, completely immerse the composite material round rod in the heating liquid, and remelt the low-melting-point alloy core after heating to recycle the low-melting-point alloy.

[0052] The bottom of the furnace body 103 has two outlets. The one closer to the bottom of the furnace body is the cleaning outlet 109, and the one higher than the cleaning outlet 109 is the extrusion outlet 110. The two outlets are located on both sides of the furnace body 103. The cleaning outlet 109 is used for regular cleaning of the alloy smelting furnace. There is a switching valve 111 on the cleaning outlet 109 to control the opening and closing of the cleaning outlet 109. The extrusion outlet 110 is used to connect to the elbow pipe 112. There is also a switching valve 111 on the extrusion outlet 110 to control the opening and closing. The elbow pipe 112 is connected to the extrusion die cavity 113. Inside the extrusion die cavity 113, there is a screw rod 114. One end of the screw rod 114 is connected to a screw motor 116 after passing through a motor fixing plate 115. The screw motor drives the screw rod to rotate. The screw rod 114 is used to push the liquid alloy forward continuously. The other end of the extrusion die cavity 113 is connected to an extrusion head 117. An extrusion die 118 is inlaid on the extrusion head 117. A cooling device 119 is connected in front of the extrusion die 118. The cooling device 119 is used to cool the low-melting-point alloy mold core 7. The formed low-melting-point alloy mold core is obtained by extrusion using the extrusion die. After cooling, it forms a certain hardness.

[0053] The turning center of the centerless lathe 2 is concentric with the extrusion die 118, which can straighten the low-melting-point alloy mold core. After coming out of the alloy smelting device 1, the low-melting-point alloy mold core 7 enters the centerless lathe 2 after passing through the roller. The centerless lathe 2 will turn the low-melting-point alloy mold core 7 to the precise standard size. After passing through the traction roller, the low-melting-point alloy mold core 7 can enter the winding and wrapping assembly 4 as a mold core.

[0054] The yarn stand 3 is used to place the yarn balls and at the same time provide a constant tension for the yarn. There are two yarn stands. A channel is formed between the two yarn stands for the low-melting-point alloy mold core to pass through, providing space for the movement of the mold core. The required inner layer yarn and outer layer yarn can be respectively led out from the yarn balls.

[0055] The pulling and winding assembly 4 includes a pulling and winding fixing frame 401. A vertical plate 402 is fixed on the pulling and winding fixing frame 401. A yarn threading cylinder 403 is fixed on the vertical plate 402. The low melting point alloy mold core 7 passes through the center of the yarn threading cylinder 403. A mold core hole is provided on the yarn threading cylinder 403, and holes for passing yarns are evenly arranged around the upper mold core hole. At the same time, a rotatable turntable 404 is installed on the other side of the vertical plate 402. A winding yarn cylinder 405 is fixed on the turntable 404. The winding yarn cylinder 405 is used to place winding yarn bobbins. The turntable 404 is connected to a motor 406 at the bottom through a belt 412, and the turntable is driven to rotate by the motor. There is a pre-impregnation tank 407 on the vertical plate 402. The pre-impregnation tank is filled with resin. There is a yarn discharging plate 413 that can be adjusted up and down in the pre-impregnation tank 407. The yarn discharging plate 413 is used to pass through the outer layer of yarns and pre-impregnate the outer layer of yarns with resin. The bottom of the pre-impregnation tank 407 is connected to the yarn threading cylinder 403 through a diversion pipe 414. The resin will enter the yarn threading cylinder 403 from the pre-impregnation tank 407 through the diversion pipe 414 to ensure that both the inner layer and the outer layer of yarns have resin. There are two switches 415 on the diversion pipe and the yarn threading cylinder, which can be valves. The switches are used to control the resin flow. After the low melting point alloy mold core 7 leaves the yarn threading cylinder 403, the inner layer of yarns coming out of the threading holes around the mold core will closely adhere to the low melting point alloy mold core 7. Then, the winding yarns coming out of the winding yarn cylinder will tightly wind the inner layer of yarns around the low melting point alloy mold core 7, and then enter the mold.

[0056] The mold includes an upper heating mold 408, a lower heating mold 409 and an outer mold 410. The outer mold 410 is arranged at the layered position of the upper heating mold and the lower heating mold. The lower heating mold 409 is fixed on the winding and fixing frame 401 through a lead screw 416. The upper heating mold 408 is installed on the surface of the lower heating mold 409. Heating rods are installed on the upper heating mold and the lower heating mold to heat the outer mold 410. There is a yarn distributor 411 at the front end of the outer mold 410 for passing through the outer layer of yarn. The yarn distributor 411 evenly arranges the outer layer of yarn on the wound low-melting-point alloy mold core 7. Then, the arranged outer layer of yarn and the wound mold core enter the outer mold 410 together. The resin is heated and cured in the outer mold 410 and then leaves the mold. At this time, the resin on the yarn is cured and formed. Then the whole enters the traction machine 5. At this time, the round rod structure leaving the outer mold 410 from the inside to the outside is successively a solid low-melting-point alloy mold core 7, an inner layer of vertical yarn, a winding yarn and an outer layer of vertical yarn. Since the yarns are all pre-impregnated with resin, during the pultrusion process, the three layers of yarns are all squeezed more densely and form an integral solid structure after curing. The traction machine 5 uses an ordinary belt-type traction machine. Since the round rod is completely solid, the traction machine 5 will not flatten the round rod. After the round rod leaves the traction machine 5, it enters the cutting machine 6 and is cut according to the required length. The cut round rod is placed on the round rod placement rack 108 on the alloy smelting furnace 101 to melt the internal low-melting-point alloy mold core and then washed with water to obtain the finished product of the composite material round tube. That is to say, there is no low-melting-point alloy mold core in the finished product. However, by utilizing the main role of the low-melting-point alloy mold core, the preparation process is more efficient, and the quality is higher, and the yield rate of good products is also higher.

[0057] The forming temperature of the winding round rod resin system is about 140°C - 160°C. The heat distortion temperature of the obtained round rod by winding is about 230°C. The melting temperature of the low-melting-point alloy is more than 20°C lower than the heat distortion temperature of the round rod. Therefore, remelting the low-melting-point alloy will not have an adverse effect on the round rod, and at the same time, corresponding annealing treatment can be carried out on the composite material round rod.

[0058] In the present invention, a low-melting-point alloy is used as the mold core, and the winding and forming of the yarn is carried out by means of a meltable mold core. Moreover, for the preliminarily cured composite material round rod, it is put back into the alloy smelting furnace for heating again to melt the internal low-melting-point alloy mold core and obtain reuse. In this way, the material loss is saved, and at the same time, the yield rate of good products and the product quality are improved.

[0059] It should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A production device for a composite material round tube, characterized in that, it includes a sequentially arranged alloy smelting device, a centerless lathe, a yarn rack, a drawing and winding assembly, a tractor and a cutting machine; The alloy smelting device includes an alloy smelting furnace and an alloy extrusion device, which is used to melt the core inside the composite material round rod for repeated recycling, and at the same time extrude the low melting point alloy core. The core inside the composite material round rod is a low melting point alloy core; The centerless lathe is installed in the downstream area of the alloy smelting device and is used to process and calibrate the low melting point alloy core to the required size and precision; The yarn rack is installed in the downstream area of the centerless lathe and is used to place yarn balls, with a space left in the middle to provide a moving space for the low melting point alloy core; The drawing and winding assembly is installed in the downstream area of the yarn rack and is used to draw and wind the yarn on the surface of the low melting point alloy core, so that an outer protective layer is formed on the surface of the low melting point alloy core, and then the low melting point alloy core enters the mold for solidification and forming to obtain a solid composite material round rod; The tractor is installed in the downstream area of the drawing and winding assembly and is used to pull the extruded composite material round rod; The cutting machine is installed in the downstream area of the tractor and cuts off the composite material round rod led out from the tractor; The alloy smelting furnace includes a furnace body, the furnace body is made of a material that will not react with the low melting point alloy, the furnace body is filled with a heating liquid that will not react with the low melting point alloy and the composite material round rod, a heating component and a round rod placement rack are arranged in the furnace body, the round rod placement rack is used to place the composite material round rod and completely immerse the composite material round rod in the heating liquid, a horizontal plate is arranged at the upper end of the furnace body, the round rod placement rack is connected to the horizontal plate through a lifting rod, and the density of the heating liquid is less than the density of the low melting point alloy and the two are incompatible; The alloy smelting device, the centerless lathe, the yarn rack, the drawing and winding assembly, the tractor and the cutting machine are arranged in a straight line.

2. The production device for a composite material round tube according to claim 1, characterized in that, The alloy extrusion device includes a cleaning outlet and an extrusion outlet respectively arranged on both sides of the furnace body, and the extrusion outlet is higher than the cleaning outlet. The extrusion outlet is connected to an elbow pipe, the elbow pipe is connected to an extrusion die cavity, a screw rod is arranged inside the extrusion die cavity, the screw rod is connected to a screw motor, the screw rod is used to guide the liquid low melting point alloy for extrusion molding, an extrusion head is fixed at one end of the extrusion die cavity, an extrusion die is fixed on the extrusion head, the extrusion head is connected to a cooling device, and the cooling device is used to cool the extruded low melting point alloy. Switch control valves are arranged in both the cleaning outlet and the extrusion outlet to control opening and closing.

3. The production device for a composite material round tube according to claim 2, characterized in that, The turning center of the centerless lathe is concentrically arranged with the extrusion die. After the low melting point alloy core comes out of the alloy smelting device, it enters the centerless lathe, and the centerless lathe turns the low melting point alloy core to the standard size and then enters the drawing and winding assembly.

4. The production device for a composite material round tube according to claim 3, characterized in that, The stretching and winding assembly includes a stretching and winding fixing frame, on which a vertical plate is fixed. A yarn threading cylinder is fixed on the vertical plate. A die core hole is provided on the yarn threading cylinder. A low-melting-point alloy die core passes through the center of the yarn threading cylinder. There are hole positions for passing yarn around the die core hole of the yarn threading cylinder. On the other side of the vertical plate, a rotatable turntable is installed. A winding yarn cylinder is fixed on the turntable and is used for placing winding yarn. The turntable is connected to a motor arranged at the bottom of the stretching and winding fixing frame through a belt. There is a pre-impregnation tank filled with resin on the vertical plate. A yarn arranging plate is provided in the pre-impregnation tank. The outer layer yarn entering the pre-impregnation tank passes through the yarn arranging plate to form pre-impregnation. The bottom of the pre-impregnation tank is connected to the yarn threading cylinder through a diversion pipe. The resin filled in the pre-impregnation tank will enter the yarn threading cylinder through the diversion pipe, so that both the inner layer yarn and the outer layer yarn have resin. After the low-melting-point alloy die core leaves the yarn threading cylinder, the yarn coming out of the threading holes around the die core will closely adhere to the low-melting-point alloy die core. Then, the inner layer yarn is wound around the die core through the winding yarn, and then enters the mold.

5. The production equipment for the composite material circular tube according to claim 1, characterized in that, the mold includes an upper heating mold, a lower heating mold and an outer mold. The outer mold is installed at the layered position of the upper heating mold and the lower heating mold. Heating rods are provided on both the upper heating mold and the lower heating mold for heating the outer mold. A yarn discharging device is provided at the front end of the outer mold for passing through the outer layer yarn. The yarn discharging device evenly arranges the outer layer yarn on the wound low-melting-point alloy die core. The arranged outer layer yarn and the wound low-melting-point alloy die core enter the outer mold together. The resin on the low-melting-point alloy die core leaves the mold after being cured in the outer mold.

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