A preheating device for compression molding of thermoplastic composite materials

Abstract

This invention relates to the field of auxiliary equipment for thermoplastic composite molding, specifically a preheating device for thermoplastic composite compression molding, comprising a machine body, a heating device, a transmission structure, and a main control device. The machine body is divided into an upper heating chamber and a lower electrical control cabinet. The heating chamber has a front opening with a front sliding door and a rear opening with a rear lifting door. The heating device is located inside the heating chamber and includes an upper graphene heating plate and a lower graphene heating plate located on the upper and lower sides of the heating chamber. The transmission structure is connected to the upper graphene heating plate and drives the upper graphene heating plate to move up and down. This invention uses symmetrical graphene heating plates for heating, and the spacing between the heating plates can be adjusted through the transmission structure to accommodate materials of different thicknesses. The front sliding door and rear lifting door design ensure heat preservation during heating and facilitate material feeding. It can be highly matched with the molding machine to achieve rapid material feeding after heating, greatly reducing heat loss.

Description

Technical Field

[0001] This invention relates to the field of auxiliary equipment for thermoplastic composite molding, specifically a preheating device for thermoplastic composite compression molding. Background Technology

[0002] Continuous carbon fiber reinforced thermoplastic composites are widely used in aerospace, automotive manufacturing, and sporting goods industries due to their excellent properties such as high strength, lightweight, and corrosion resistance. During compression molding, the carbon fiber laminate needs to be preheated before being placed in the mold to ensure the material temperature and reduce subsequent molding pressure.

[0003] Traditional oven heating methods suffer from problems such as rapid heat loss and rapid temperature drop during feeding, resulting in carbon fiber laminates being transferred to the molding press at a temperature lower than the process requirements, thus affecting the performance of the final product.

[0004] Therefore, there is an urgent need for a preheating device that can deliver materials conveniently and with minimal heat loss. Summary of the Invention

[0005] The purpose of this invention is to provide a preheating device for compression molding of thermoplastic composite materials, enabling rapid and uniform preheating of composite material sheets. This solves the technical problems in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a preheating device for thermoplastic composite material compression molding, comprising a machine body, a heating device, a transmission structure, and a main control device;

[0007] The machine body is divided into an upper heating cavity and a lower electrical control cabinet. The heating cavity is a hollow structure that runs through the front and back. The front opening of the heating cavity is provided with a front sliding door, and the rear opening is provided with a rear lifting door.

[0008] The heating device is disposed in the heating cavity, including an upper graphene heating plate and a lower graphene heating plate disposed on the upper and lower sides of the heating cavity; the central control device is electrically connected to the heating device and controls the heating device to heat through the central control device.

[0009] The transmission structure is connected to the upper graphene heating plate and drives the upper graphene heating plate to move up and down.

[0010] Furthermore, the heating device also includes a lifting rod, a lifting plate, an upper base, and a lower base;

[0011] Four lifting rods are vertically fixed at the four corners inside the heating chamber. The four corners of the lifting plate are slidably engaged with the four lifting rods via linear bearings. The lower base is fixed at the center of the bottom of the heating chamber, and the lower graphene heating plate is horizontally fixed on the upper surface of the lower base. The upper base is fixed at the center of the lower surface of the lifting plate, and the upper graphene heating plate is horizontally fixed on the lower surface of the upper base. The upper and lower graphene heating plates are parallel to each other vertically and their working surfaces are opposite each other. The transmission structure is connected to the lifting plate, and the lifting plate is driven to move up and down along the lifting rods through the transmission structure.

[0012] Furthermore, several high-temperature resistant ceramic support columns are arranged around the upper surface of the lower graphene heating plate to support the composite material plate to be preheated.

[0013] Furthermore, the transmission structure includes a nut movement lifting mechanism, a first bevel gear, a second bevel gear, and a screw;

[0014] The nut lifting mechanism is installed on the upper right side of the machine body. The nut lifting mechanism includes a housing, a worm gear, a handwheel, and a rotating shaft. The handwheel is connected to the worm gear. The worm gear drives the worm gear to rotate. The rotating shaft is connected to the worm gear key. The rotating shaft rotates with the worm gear. Rotating the handwheel drives the rotating shaft to rotate.

[0015] The first bevel gear is fixedly installed on the left end of the rotating shaft; the screw is vertically arranged on the central axis of the heating cavity, and the upper end of the screw is rotatably installed on the inner wall of the top of the heating cavity; the second bevel gear is fixed on the upper end of the screw, and the first bevel gear and the second bevel gear mesh perpendicularly; the center of the lifting plate has a through threaded hole, and the lower end of the screw passes through the threaded hole to form a screw-nut transmission engagement; the rotational power output by the nut movement lifting machine is transmitted to the screw through the bevel gear reversal, and the rotation of the screw drives the lifting plate to move vertically along the lifting rod to adjust the distance between the upper graphene heating plate and the lower graphene heating plate.

[0016] Furthermore, one side of the front sliding door is hinged to the front side of the machine body, and can rotate horizontally around the hinge axis to open and close the front opening; vertical slots are provided on the left and right sides of the rear opening of the machine body, and the left and right edges of the rear sliding door are engaged in the slots, and can slide vertically along the slots to open and close the rear opening.

[0017] Furthermore, the main control device is installed inside the electrical control cabinet in the lower half of the machine body. The main control device includes a temperature control panel, a main switch, and an emergency stop switch. The temperature control device adopts a PID temperature controller. Temperature sensors are built into both the upper and lower graphene heating plates, and the temperature sensors are connected to the PID temperature controller.

[0018] Furthermore, it also includes support feet; the support feet are adjustable feet with four installed at the bottom of the machine body.

[0019] Beneficial effects

[0020] This invention employs symmetrical graphene heating plates for bidirectional heating, resulting in rapid and uniform temperature rise. The spacing between the heating plates can be adjusted via a transmission structure to accommodate materials of varying thicknesses and heating rates. The front sliding door and rear lifting door design ensure heat preservation during heating while facilitating material feeding. It is highly compatible with molding machines, enabling rapid material feeding after heating and significantly reducing heat loss. It features temperature control and safety protection functions, making it easy to operate and highly reliable. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 This is a schematic diagram of the overall structure of the preheating device disclosed in this invention;

[0023] Figure 2 This is a partial structural schematic diagram of the heating device disclosed in this invention;

[0024] Figure 3 This is a schematic diagram of the internal structure of the transmission structure disclosed in this invention;

[0025] Figure 4 This is a schematic diagram of the nut movement lifting mechanism disclosed in this invention;

[0026] Figure 5 This is a schematic diagram of the panel arrangement of the master control device disclosed in this invention.

[0027] In the diagram: 1. Body; 11. Rear sliding door; 12. Front sliding door; 13. Support feet; 2. Heating device; 21. Lifting rod; 22. Lifting plate; 23. Upper base; 24. Upper graphene heating plate; 25. Lower base; 26. Lower graphene heating plate; 3. Transmission structure; 31. Nut-driven lifting mechanism; 32. First bevel gear; 33. Second bevel gear; 34. Screw; 35. Handwheel; 36. Rotating shaft; 41. Temperature control device; 42. Main switch; 43. Emergency stop switch. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] To achieve the above objectives, the present invention provides the following technical solutions, such as... Figure 1-5 As shown, a preheating device for compression molding of thermoplastic composite materials is provided. This device is an auxiliary equipment for compression molding production lines and is suitable for preheating composite materials such as carbon fiber laminates and prepregs. It can significantly improve the quality of compression molding and increase production efficiency. It includes a machine body 1, a heating device 2, a transmission structure 3, and a central control device. The entire device is arranged on the feed side of the compression molding machine, with its rear end facing the inlet of the compression molding machine, and is used for preheating carbon fiber laminates before molding.

[0030] The machine body 1 is divided into two parts: an upper heating chamber and a lower electrical control cabinet. The upper heating chamber is a rectangular cavity that runs from front to back, serving as the working space for preheating operations. The lower electrical control cabinet is a closed structure used for installing electrical components and wiring. A front sliding door 12 is hinged to the left side of the front opening of the heating chamber. The front sliding door 12 can rotate horizontally around the hinge axis, covering the front opening when closed and allowing the workpiece to be preheated to be placed from the front when open. Vertical U-shaped slots are welded to the left and right sides of the rear opening of the heating chamber. The left and right edges of the rear lifting door 11 are embedded in the slots and can slide up and down along the slots. Pulling it upwards opens the rear opening, and lowering it closes the rear opening. The front sliding door 12 and the rear lifting door 11 form a sealed and insulated heating space, effectively reducing heat loss.

[0031] Furthermore, the heating device 2 is disposed inside the heating cavity. The heating device 2 also includes an upper graphene heating plate 24, a lower graphene heating plate 26, a lifting rod 21, a lifting plate 22, an upper base 23, and a lower base 25;

[0032] Four lifting rods 21 are vertically fixed at the four corners inside the heating chamber. The lifting plate 22 is a rectangular steel plate with linear bearings installed at its four corners, which are respectively fitted onto the four lifting rods 21. The four corners of the lifting plate 22 slide with the four lifting rods 21 through the linear bearings, forming a vertically guiding lifting structure to ensure that the lifting plate 22 remains horizontal during the lifting process. The lower base 25 is fixed to the center of the bottom of the heating chamber by bolts, and the lower graphene heating plate 26 is laid flat and fixed to the upper surface of the lower base 25. The upper base 23 is fixed to the center of the lower surface of the lifting plate 22 by bolts, and the upper graphene heating plate 24 is fixed to the lower surface of the upper base 23. Both graphene heating plates are planar infrared heating elements with their working surfaces facing each other and arranged in parallel. After being powered on, they can emit far-infrared rays to provide bidirectional radiant heating to the carbon fiber plate placed between them.

[0033] Furthermore, high-temperature resistant ceramic support columns are provided at the four corners of the upper surface of the lower graphene heating plate 26 to support the plate to be preheated, so that the lower surface of the plate and the heating plate maintain a uniform radiation gap, avoid the plate directly contacting the heating plate and causing local overheating, and ensure heating uniformity.

[0034] Furthermore, the transmission structure 3 is installed on the machine body 1 and is used to drive the lifting plate 22 to reciprocate up and down along the lifting rod 21; the transmission structure 3 includes a nut-moving lifting mechanism 31, a first bevel gear 32, a second bevel gear 33 and a screw 34;

[0035] When the rear sliding door 11 and the front sliding door 12 are opened, the heat in the heating chamber is dissipated outward and upward; the nut movement lift 31 is set on the upper right side of the body 1 to avoid the heat dissipated from the front and top of the body 1.

[0036] The nut lifting machine 31 is an externally purchased device, and its structure is existing technology, including a housing, a worm gear, a worm shaft, a handwheel 35, and a rotating shaft 36; the handwheel 35 is connected to the worm shaft; the worm shaft drives the worm gear to rotate, and the rotating shaft 36 is connected to the worm gear key; the rotating shaft 36 rotates with the worm gear, and rotating the handwheel 35 drives the rotating shaft 36 to rotate.

[0037] The first bevel gear 32 is fixedly installed at the left end of the rotating shaft 36; the screw 34 is vertically arranged on the central axis of the heating cavity, and its upper end is fixed to the top of the cavity by a bearing with a seat, allowing it to rotate freely; the upper end of the screw 34 is fixedly installed with the second bevel gear 33 by a flat key, and the first bevel gear 32 and the second bevel gear 33 mesh perpendicularly, converting the horizontal rotation of the rotating shaft 36 into the vertical rotation of the screw 34. The center of the lifting plate 22 is machined with an internal threaded through hole, through which the screw 34 passes and engages with its thread, forming a screw-nut transmission pair. When the handwheel 35 is turned clockwise, power is transmitted to the screw 34 via the worm gear reducer and bevel gear reversal. The clockwise rotation of the screw 34 causes the lifting plate 22 to move downwards along the lifting rod 21, reducing the heating distance; when the handwheel 35 is turned counterclockwise, the lifting plate 22 moves upwards, increasing the heating distance. The worm gear mechanism has a self-locking characteristic; after the handwheel 35 is stopped, the lifting plate 22 can lock itself at the current height and will not slide down due to its own weight.

[0038] Combination Figure 5 As shown, the main control unit is integrated into the lower electrical control cabinet, responsible for the power supply and temperature control of the entire machine. The temperature control device 41 uses an intelligent PID temperature controller, installed on the upper part of the electrical control cabinet door. The panel displays the set temperature and real-time temperature, and supports temperature parameter setting and saving. Both graphene heating plates have built-in temperature sensors, and the sensor signal lines are connected to the temperature controller, forming a closed-loop control circuit. The main switch 42 is a self-locking button with an indicator light, installed below the temperature control device 41. Pressing it powers on the entire machine and illuminates the indicator light; pressing it again de-energizes the machine. The emergency stop switch 43 is a red mushroom-shaped button, installed in a prominent position on the right side of the cabinet door. It uses normally closed contacts connected in series in the main power supply circuit. In an emergency, pressing the emergency stop switch 43 immediately cuts off the power supply to the entire machine, ensuring the safety of the equipment and personnel.

[0039] Furthermore, adjustable support feet 13 are installed at the four corners of the bottom of the machine body 1. The overall height and level of the equipment can be adjusted by rotating the foot bolts, so that the height of the heating chamber is consistent with the inlet height of the matching molding machine, ensuring that the preheated sheet can be pushed horizontally into the molding machine, minimizing temperature drop.

[0040] The specific usage process and working principle of this invention are as follows:

[0041] Depending on the thickness and process requirements of the carbon fiber laminate to be preheated, adjust the spacing between the upper and lower graphene heating plates by turning handwheel 35 to ensure optimal radiant heating. Close the main switch 42 and set the preheating temperature through the temperature control device 41. After the temperature control system is activated, the graphene heating plates begin to heat up. Once the temperature reaches the set value and stabilizes, the preheating operation can begin.

[0042] Keeping the rear sliding door 11 closed, turn the front sliding door 12 outwards to open it. Place the carbon fiber laminate to be preheated horizontally into the heating chamber, positioning it on the ceramic support column, ensuring the board is centered and not tilted. Close the front sliding door 12, creating a sealed space within the heating chamber. The board rapidly heats up under bidirectional infrared radiation from both above and below. During preheating, the temperature control system adjusts the heating power in real time to maintain a stable temperature.

[0043] After the preset preheating time is reached, open the front sliding door 12 and lift the rear sliding door 11. Use the high-temperature resistant pusher to push the sheet material out from the rear from the front. The sheet material enters the mold cavity of the molding machine horizontally, completing the feeding. After feeding is completed, lower the rear sliding door 11 to insert the next sheet material for continued preheating.

[0044] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A preheating device for compression molding of thermoplastic composite materials, characterized in that, It includes the fuselage (1), heating device (2), transmission structure (3), and main control device; The body (1) is divided into an upper heating cavity and a lower electrical control cabinet. The heating cavity is a hollow structure that runs through the front and back. The front opening of the heating cavity is provided with a front sliding door (12), and the rear opening is provided with a rear lifting door (11). The heating device (2) is disposed in the heating cavity, including an upper graphene heating plate (24) and a lower graphene heating plate (26) disposed on the upper and lower sides of the heating cavity; the main control device is electrically connected to the heating device (2) and controls the heating device (2) to heat through the main control device; The transmission structure (3) is connected to the upper graphene heating plate (24) and drives the upper graphene heating plate (24) to move up and down.

2. The preheating device for compression molding of thermoplastic composite materials according to claim 1, characterized in that: The heating device (2) also includes a lifting rod (21), a lifting plate (22), an upper base (23), and a lower base (25); Four lifting rods (21) are vertically fixed at the four corners inside the heating cavity. The four corners of the lifting plate (22) are slidably connected to the four lifting rods (21) through linear bearings. The lower base (25) is fixed at the center of the bottom of the heating cavity. The lower graphene heating plate (26) is horizontally fixed on the upper surface of the lower base (25). The upper base (23) is fixed at the center of the lower surface of the lifting plate (22). The upper graphene heating plate (24) is horizontally fixed on the lower surface of the upper base (23). The upper graphene heating plate (24) and the lower graphene heating plate (26) are parallel to each other and their working surfaces are opposite to each other. The transmission structure (3) is connected to the lifting plate (22). The transmission structure (3) drives the lifting plate (22) to move up and down along the lifting rods (21).

3. The preheating device for compression molding of thermoplastic composite materials according to claim 2, characterized in that: The upper surface of the lower graphene heating plate (26) is provided with several high-temperature resistant ceramic support columns to support the composite material plate to be preheated.

4. The preheating device for compression molding of thermoplastic composite materials according to claim 2, characterized in that: The transmission structure (3) includes a nut movement lifting mechanism (31), a first bevel gear (32), a second bevel gear (33), and a screw (34); The nut lifting mechanism (31) is installed on the upper right side of the machine body (1). The nut lifting mechanism (31) includes a housing, a turbine, a worm gear, a handwheel (35), and a rotating shaft (36). The handwheel (35) is connected to the worm gear. The worm gear drives the turbine to rotate. The rotating shaft (36) is connected to the turbine key. The rotating shaft (36) rotates with the turbine. Rotating the handwheel (35) drives the rotating shaft (36) to rotate. The first bevel gear (32) is fixedly installed on the left end of the rotating shaft (36); the screw (34) is vertically installed on the central axis of the heating cavity, and the upper end of the screw (34) is rotatably installed on the inner wall of the top of the heating cavity; the second bevel gear (33) is fixed on the upper end of the screw (34), and the first bevel gear (32) and the second bevel gear (33) mesh vertically; the center of the lifting plate (22) is provided with a through threaded hole, and the lower end of the screw (34) passes through the through threaded hole and forms a screw-nut transmission fit; the rotational power output by the nut movement lifting machine (31) is transmitted to the screw (34) through the bevel gear reversal, and the screw (34) rotates to drive the lifting plate (22) to move vertically along the lifting rod (21) to adjust the distance between the upper graphene heating plate (24) and the lower graphene heating plate (26).

5. The preheating device for compression molding of thermoplastic composite materials according to claim 1, characterized in that: One side of the front sliding door (12) is hinged to the front side of the body (1) and can rotate horizontally around the hinge axis to open and close the front opening; vertical slots are provided on the left and right sides of the rear opening of the body (1), and the left and right edges of the rear lifting door (11) are engaged in the slots and can slide vertically along the slots to open and close the rear opening.

6. The preheating device for compression molding of thermoplastic composite materials according to claim 1, characterized in that: The main control device is installed inside the electrical control cabinet in the lower half of the machine body (1). The main control device includes a temperature control device (41) panel, a main switch (42) and an emergency stop switch (43). The temperature control device (41) adopts a PID temperature controller. The upper graphene heating plate (24) and the lower graphene heating plate (26) are both equipped with built-in temperature sensors. The temperature sensors are connected to the PID temperature controller signal.

7. The preheating device for compression molding of thermoplastic composite materials according to claim 1, characterized in that: It also includes support feet (13); the support feet (13) are adjustable feet with four installed at the bottom of the body (1).

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