An automatic forming device for composite material special-shaped curved surface

Abstract

The present invention provides an automatic forming device for composite material special-shaped curved surface, comprising a machine tool conveying slide, a movable workbench, a mold, a visual inspection device and an upper mold lifting device; the mold is arranged on the movable workbench, the machine tool conveying slide conveys the movable workbench with the mold to the upper mold lifting device, and the visual inspection device detects the surface morphology of the prepreg on the mold during the conveying process, and the upper mold lifting device has a pair of rollers in the diaphragm frame, and the bottom of the diaphragm frame is fixed with a ductile diaphragm, and the pair of rollers is used to adjust the drape deformation of the diaphragm in the diaphragm frame according to the information detected by the visual inspection device, so that the size of the diaphragm used to compact the prepreg is adapted to the prepreg. The present invention obtains the position of the complex curved surface of the prepreg in the mold by detecting the inner surface morphology of the mold through the visual inspection device, and feeds back to the pair of rollers and adjusts the drape deformation of the diaphragm, so as to realize the pre-deformation of the diaphragm to the prepreg.

Description

Technical Field

[0001] The invention relates to the field of composite material molding, and in particular to an automatic molding device for composite material special-shaped curved surfaces. Background Art

[0002] In the aerospace field, composite materials have been increasingly widely used due to their light weight, high strength and fatigue resistance, such as in key parts such as helicopter blades and aircraft engines, and have gradually shifted from non-load-bearing components to load-bearing components. They have become the main structural material for the new generation of aerospace equipment.

[0003] At present, the industry generally adopts manual stacking to form high-performance composite preforms. The prepreg is directly laid on the mold to make the preform. The main shortcomings are as follows: (1) Low production efficiency: The degree of automation is low and it relies heavily on manual operation, resulting in low stacking efficiency; (2) Unstable molding quality: Manual stacking makes it difficult to ensure the positioning accuracy and stacking quality of the prepreg on the mold, and the molding quality is greatly affected by the workers' technical level.

[0004] Improving the automation of the equipment can effectively improve the molding efficiency of the preform. Composite material thermal insulation preforming is a molding method proposed and gradually applied in recent years. It can achieve rapid molding of preforms and has the advantages of high production efficiency and low cost.

[0005] Chinese patent (CN201910927837.3) discloses "A hot diaphragm preforming device for composite shell and its working method", which is used for hot diaphragm preforming of composite shell. The device includes a workbench, a diaphragm device, a heat insulation door, a heating chamber, a mold, an exhaust system and a control system, and has the characteristics of double molds and three stations. The device and its working method are suitable for multi-station automated molding of composite preforms, optimize the overall process steps, reduce the complexity of the process flow, and improve the molding efficiency.

[0006] The Chinese patent (CN201520675082.X) discloses a "fabric preform preparation device for rapid prototyping composite materials", which proposes a fabric preform preparation device for rapid prototyping composite materials, including an upper mold, a lower mold, and a controller for controlling the temperature, pressure, opening, and closing of the upper mold and the lower mold, which quickly compacts, heats, and cools the fabric with a setting agent to obtain a fabric preform with certain shape requirements. The fabric with a setting agent is quickly compacted, heated, and cooled by vacuum negative pressure to obtain a fabric preform with certain shape requirements. The deformability of the high elastic film can realize a preform of almost any thickness and geometric shape, and the obtained preform is dense, uniform in thickness, and has good anti-deformation ability.

[0007] The above two patents are applicable to the preforming of composite fabrics. The vacuum negative pressure is used to cause a large deformation of the diaphragm to compact the material. However, the initial profile of the diaphragm of the device is fixed and cannot be adjusted according to the actual shape of the composite component. When the prepreg on the mold with a deep cavity is formed, the air pressure generated inside the device causes the deformation of the diaphragm at the deep cavity position to be insufficient to achieve a good fit between the diaphragm and the mold surface, and defects such as gaps and bridging wrinkles are easily formed at the corners of the mold.

[0008] The above two patents are applicable to the preforming of composite fabrics, but both are only formed by applying vacuum negative pressure, and the maximum pressure that can be achieved can only reach less than one atmosphere.

[0009] In addition, these two devices only heat the diaphragm device, but do not heat the mold itself. These two devices have the disadvantages of low device stability, poor molding quality, and easy bridging at the corners and concave cavities of the mold, and are not suitable for preform molding of composite material components with deep cavity structures.

[0010] In order to solve the above problems, ensure the preform molding quality of composite materials with deep cavity structures, and improve the stability of the device, it is an urgent issue to develop a thermal diaphragm preforming device for composite materials with deep cavity structures. Summary of the invention

[0011] In view of the above technical problems, an automatic forming device for composite material special-shaped curved surfaces is provided.

[0012] An automatic forming device for composite material special-shaped curved surface, comprising a machine tool conveying slide, a movable workbench, a mold, a visual inspection device and an upper mold lifting device;

[0013] The movable workbench is arranged on the machine tool conveying slide and moves linearly along the machine tool conveying slide under the drive of the machine tool conveying slide;

[0014] The mold is installed on the movable workbench, the mold has a first vacuum hole connected to the vacuum system, and a prepreg is arranged in the mold;

[0015] The visual inspection device is installed on the side wall of one end of the upper mold lifting device entering toward the movable workbench, and is used to inspect the surface morphology of the prepreg that has been preliminarily bonded to the inner surface of the mold;

[0016] The upper mold lifting device includes a frame, a diaphragm frame arranged in the frame, a lifting mechanism for driving the diaphragm frame to lift and lower, and roller mechanisms respectively arranged on both sides of the inner wall of the diaphragm frame;

[0017] The bottom of the diaphragm frame is fixed with a ductile diaphragm, and the roller mechanism is used to adjust the drape deformation of the diaphragm in the diaphragm frame according to the information detected by the visual detection device, so that the size of the diaphragm used to compact the prepreg is adapted to the prepreg;

[0018] After the diaphragm frame is lowered and docked with the mold, a lower closed space is formed between the diaphragm and the mold, and an upper closed space is formed between the diaphragm and the diaphragm frame. The vacuum system evacuates the lower closed space through the first vacuum hole so that the diaphragm tightly compacts the prepreg and the prepreg is completely fitted with the inner surface of the mold.

[0019] Preferably, a pressurizing hole is provided in the diaphragm frame, and the pressurizing hole is connected to an air source for inflating and pressurizing the upper closed space.

[0020] Preferably, a heating reservoir is provided in the diaphragm frame for heating the upper closed space.

[0021] Preferably, a heating rod and a thermocouple probe are provided in the movable workbench.

[0022] The first vacuum holes are arranged on the side wall and the bottom of the mold.

[0023] Preferably, a second vacuum hole connected to the vacuum system is provided at a corner of the mold, and the vacuum system enables the prepreg to fit tightly with the mold at the corner of the mold through the second vacuum hole.

[0024] Preferably, an electromagnetic clamp is installed at the bottom of the diaphragm frame, and the electromagnetic clamp is used to fix the diaphragm frame to the movable workbench.

[0025] Preferably, the diaphragm frame is provided with a limiting device matched with the frame, and the limiting device is used to limit the lifting stroke of the diaphragm frame.

[0026] Preferably, the visual inspection device is a line scan camera.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] 1. The present invention uses a visual inspection device to scan the surface morphology of the prepreg that has been preliminarily bonded to the inner surface of the mold, and feeds back the position and depth of the deep cavity to the roller mechanism and adjusts the diaphragm overhang deformation, thereby achieving the diaphragm's shape-conforming pre-deformation of the prepreg. For example, if there is a larger depression in the center of the prepreg, the roller mechanism needs to adjust the diaphragm overhang more.

[0029] 2. The present invention increases the deformation capacity of the diaphragm by applying a combination of positive pressure and negative pressure, ensures the molding quality of the prepreg, and reduces the bridging phenomenon of the prepreg in the corners of the mold and the cavity.

[0030] 3. In addition to heating the upper mold lifting device, the present invention also heats the mold and performs feedback adjustment through a thermocouple probe, thereby ensuring good sliding properties of the prepreg and deformation capacity of the diaphragm and reducing the rebound phenomenon of the prepreg after preforming.

[0031] 4. The present invention is aimed at the flexible automatic molding of large composite materials. By installing an electromagnetic clamp between the diaphragm frame and the movable workbench, it is ensured that no vacuum loss and pressure loss occur during the molding process.

[0032] Based on the above reasons, the present invention can be widely promoted in the fields of composite material molding and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a schematic structural diagram of an automatic forming device for special-shaped curved surfaces of composite materials in a specific embodiment of the present invention.

[0035] Figure 2 It is a schematic diagram of the structure of a machine tool conveying slide in a specific implementation manner of the present invention.

[0036] Figure 3 It is a schematic diagram of the mold structure in a specific implementation manner of the present invention.

[0037] Figure 4 It is a schematic diagram of a movable workbench in a specific implementation manner of the present invention.

[0038] Figure 5 It is a three-dimensional view of the upper mold lifting device in a specific implementation manner of the present invention.

[0039] Figure 6 It is a three-dimensional view of the diaphragm frame in a specific implementation manner of the present invention.

[0040] Figure 7 It is a side view of the diaphragm frame in a specific embodiment of the present invention.

[0041] In the figure: 1. Machine tool conveyor slide; 2. Movable workbench; 3. Mould; 31. First vacuum hole; 32. Second vacuum hole; 33. Heating rod; 34. Thermocouple probe; 35. Heating wire connection joint; 4. Visual inspection device; 5. Upper mould lifting device; 51. Machine frame; 52. Diaphragm frame; 53. Roller mechanism; 54. Pressurization hole; 55. Heating reservoir; 56. Limiting device; 57. Electromagnetic clamp; 6. Diaphragm. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be clear that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0046] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0047] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0048] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0049] like Figures 1 to 7 As shown, a composite material special-shaped curved surface automatic molding device includes a machine tool conveying slide 1, a movable workbench 2, a mold 3, a visual inspection device 4 and an upper mold lifting device 5;

[0050] The movable workbench 2 is arranged on the machine tool conveying slide 1, and moves linearly along the machine tool conveying slide 1 under the drive of the machine tool conveying slide 1; the machine tool conveying slide 1 is provided with a guide rail, and the bottom of the movable workbench 2 is provided with a slider matched with the guide rail, and the machine tool conveying slide is provided with a horizontal driving mechanism for driving the movable workbench 2 to move linearly along the guide rail. The horizontal driving mechanism can adopt a servo motor to drive a lead screw (the servo motor is fixed on the machine tool conveying slide 1, connected to the input end of the lead screw, and the output end of the lead screw is connected to the movable workbench), or an electric push rod, or a motor driven gear rack, and there are many ways. The movable workbench 2 has a heating rod 33, a thermocouple sensor 34 and a heating wire connection joint 35.

[0051] The mold 3 is mounted on the movable workbench 2. The mold 3 has a first vacuum hole 31 connected to the vacuum system. The first vacuum hole 31 is located on the bottom surface and side wall of the mold. Prepreg is arranged in the mold 3. The mold 3 has a second vacuum hole 32 connected to the vacuum system at the corner. The vacuum system makes the prepreg fit closely with the mold 3 at the corner of the mold 3 through the second vacuum hole 32.

[0052] The visual inspection device 4 is installed on the side wall of one end of the upper mold lifting device 5 entering toward the movable workbench 2, and is used to detect the surface morphology of the prepreg in the mold 3; the visual inspection device 4 is a line scan camera.

[0053] The upper mold lifting device 5 includes a frame 51, a diaphragm frame 52 arranged in the frame 51, a lifting mechanism for driving the diaphragm frame 52 to rise and fall, and a pair of roller mechanisms 53 respectively arranged on both sides of the inner wall of the diaphragm frame 52;

[0054] The lifting mechanism can be driven by a servo motor to drive a lifting screw, the servo motor is fixedly connected to the frame 51, the output end of the servo motor is connected to the input end of the lifting screw, and the output end of the lifting screw is fixedly connected to the diaphragm frame. The diaphragm frame 52 is provided with a limit device 56 that cooperates with the frame 51, and the limit device 56 is used to limit the lifting stroke of the diaphragm frame 52.

[0055] The roller mechanism 53 uses two rollers, one of which is an active roller connected to a roller motor, and the other is a driven roller. The diaphragm is located in the gap between the active roller and the driven roller, and the movement is achieved through the cooperation of the active roller and the driven roller, thereby adjusting its suspension deformation in the diaphragm frame 52.

[0056] The visual inspection device 4 is mounted on the side wall of the diaphragm frame 52;

[0057] The bottom of the diaphragm frame 52 is fixed with a ductile diaphragm 6, and the roller mechanism 53 is used to adjust the drape deformation of the diaphragm 6 in the diaphragm frame 52 according to the information detected by the visual detection device 4, so that the size of the diaphragm 6 used to compact the prepreg is adapted to the prepreg;

[0058] After the diaphragm frame 52 is lowered and docked with the mold 3, a lower closed space is formed between the diaphragm 6 and the mold 3, and an upper closed space is formed between the diaphragm 6 and the diaphragm frame 52. The vacuum system vacuums the lower closed space through the first vacuum hole 31, so that the diaphragm 6 tightly compacts the prepreg. A pressurizing hole 54 is provided in the diaphragm frame 52, and the pressurizing hole 54 is connected to the air source for inflating and pressurizing the upper closed space. A heating reservoir 55 is provided in the diaphragm frame 52 for heating the diaphragm 6. The installation end of the heating reservoir 55 is installed on the upper surface of the diaphragm frame 52, and the heating end is located in the diaphragm frame 52, and the heating reservoir 55 has a heating mechanism and a temperature sensor.

[0059] An electromagnetic clamp 57 is installed at the bottom of the diaphragm frame 52 , and the electromagnetic clamp 57 is used to fix the diaphragm frame 52 to the movable workbench 2 .

[0060] The working method of the present invention is as follows: the mold 3 is installed on the movable workbench 2 according to a predetermined position, the prepreg is arranged at a suitable position on the surface of the mold 3, and a vacuum is drawn using a vacuum system and a second vacuum hole 32, and during the vacuum drawing process, the mold 3 and the prepreg are heated by an electric heater 33.

[0061] The horizontal drive mechanism works to drive the movable workbench 2 to move below the upper mold lifting device 5. In this process, the visual inspection device 4 installed on the side wall of the diaphragm frame 52 scans the surface morphology of the prepreg, obtains the position of the deep cavity area on the surface of the prepreg and feeds it back to the roller mechanism 53. The roller mechanism 53 adjusts the drape deformation of the diaphragm 6 to obtain the conformal pre-deformation of the diaphragm 6 to the prepreg. The upper mold lifting device 5 moves vertically downward until it is completely in contact with the movable platform 2, the electromagnetic clamp 57 between the diaphragm frame 52 and the movable workbench 2 is closed, and the heating reservoir 55 starts to perform hot air heating. When the temperature sensors in the mold 3 and the heating reservoir 55 reach the set temperature requirements, the vacuum system vacuums the lower part of the diaphragm 6 through the first vacuum hole 31, and the positive pressure is applied to 2MPa above the diaphragm 6 through the boost hole 54. After 3 minutes, the electromagnetic clamp 57 is released, the upper mold lifting device 5 rises, and the movable workbench 2 is removed to obtain a composite material preform.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic forming device for composite material special-shaped curved surface, characterized in that: It includes a machine tool conveying slide, a movable workbench, a mold, a visual inspection device and an upper mold lifting device; The movable workbench is arranged on the machine tool conveying slide and moves linearly along the machine tool conveying slide under the drive of the machine tool conveying slide; The mold is installed on the movable workbench, the mold has a first vacuum hole connected to the vacuum system, and a prepreg is arranged in the mold; The visual inspection device is installed on the side wall of one end of the upper mold lifting device entering toward the movable workbench, and is used to inspect the surface morphology of the prepreg that has been preliminarily bonded to the inner surface of the mold; The upper mold lifting device includes a frame, a diaphragm frame arranged in the frame, a lifting mechanism for driving the diaphragm frame to lift and lower, and roller mechanisms respectively arranged on both sides of the inner wall of the diaphragm frame; The bottom of the diaphragm frame is fixed with a ductile diaphragm, and the roller mechanism is used to adjust the drape deformation of the diaphragm in the diaphragm frame according to the information detected by the visual detection device, so that the size of the diaphragm used to compact the prepreg is adapted to the prepreg; After the diaphragm frame is lowered and docked with the mold, a lower closed space is formed between the diaphragm and the mold, and an upper closed space is formed between the diaphragm and the diaphragm frame. The vacuum system evacuates the lower closed space through the first vacuum hole so that the diaphragm tightly compacts the prepreg and the prepreg is completely fitted with the inner surface of the mold.

2. The automatic forming device for composite material special-shaped curved surface according to claim 1, characterized in that: A pressurizing hole is provided in the diaphragm frame, and the pressurizing hole is connected to an air source and is used for inflating and pressurizing the upper closed space.

3. The automatic forming device for composite material special-shaped curved surface according to claim 1, characterized in that: A heating reservoir is provided in the diaphragm frame for heating the upper closed space.

4. The automatic forming device for composite material special-shaped curved surface according to claim 1, characterized in that: The movable workbench is provided with a heating rod and a thermocouple probe.

5. The automatic forming device for composite material special-shaped curved surface according to claim 1, characterized in that: The first vacuum holes are arranged on the side wall and the bottom of the mold.

6. The automatic forming device for composite material special-shaped curved surface according to claim 1, characterized in that: The mold corner is provided with a second vacuum hole connected to the vacuum system, and the vacuum system allows the prepreg to fit tightly with the mold at the mold corner through the second vacuum hole.

7. The automatic forming device for composite material special-shaped curved surface according to claim 1, characterized in that: An electromagnetic clamp is installed at the bottom of the diaphragm frame, and the electromagnetic clamp is used to fix the diaphragm frame to the movable workbench.

8. The automatic forming device for composite material special-shaped curved surface according to claim 1, characterized in that: The diaphragm frame is provided with a limiting device matched with the frame, and the limiting device is used to limit the lifting stroke of the diaphragm frame.

9. The automatic forming device for composite material special-shaped curved surface according to claim 1, characterized in that: The visual inspection device is a line scan camera.

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