A hot diaphragm preform experimental device

Abstract

The utility model belongs to the field of composite preforming, disclose a kind of hot diaphragm preforming experimental device, including movable heating device, movable vacuum bed, vacuum pump, mould and diaphragm;Movable heating device is equipped with the space for movable vacuum bed insertion, and the space is located in the heating range of movable heating device;Movable vacuum bed is equipped with only the cavity of upper opening;Vacuum pump is used to form the vacuum environment required in the cavity by preforming;Mould is located in the cavity;Diaphragm is used to close the opening of the cavity.The hot diaphragm preforming experimental device of the utility model adopts split design, it is convenient to carry in laboratory, and when placing mould material, operation space is large, easy to install, and it can adapt to the demand of frequently changing mould material in experimental scene.

Description

Technical Field

[0001] This utility model belongs to the field of composite material preforming and relates to an experimental device for preforming thermal insulation film. Background Technology

[0002] Composite material preforming technology is a key step in the fabrication of high-performance complex structural components. Among these technologies, thermal diaphragm preforming is widely studied due to its broad applicability and relatively low cost. In laboratory research, thermal diaphragm preforming devices are mainly used to study the influence of process parameters (temperature, vacuum level, heating rate, etc.) on preforming quality, optimize process windows, and reveal the formation mechanism of defects such as wrinkles.

[0003] Currently, most small-scale thermal insulation film preforming devices commonly used in laboratories are designed as integrated, immovable structures. However, these devices lack flexibility in practical applications and are difficult to adapt to experimental needs. Even those devices with a split design and guide rails only have a limited range of movement near the heating zone, which is insufficient to meet the demands of frequent mold material changes in experimental scenarios.

[0004] Patent CN212288845U discloses a thermal diaphragm vacuum bed, including a support, a vacuum platform, a vacuum pump, a sealing ring, and a diaphragm frame. The vacuum platform is fixed to the top of the support, and the diaphragm frame is stacked on the vacuum platform and fixed to the four sides of the thermal diaphragm through grooves and strips. Although this patent improves the fixing efficiency of the thermal diaphragm, its vacuum bed and support are a fixed integrated structure, which is not movable. In experimental scenarios, the operating space is limited when changing molds and materials, resulting in insufficient flexibility and inability to meet the experimental needs of frequent mold changes.

[0005] Patent application CN110654040A discloses a preforming device for a composite material shell with a thermal diaphragm and its operating method. The device includes a worktable, a diaphragm assembly, an insulation door, a heating chamber, a mold, an exhaust system, and a control system. The worktable is moved along a longitudinal track by a cylinder to achieve multi-station alternating operation. However, the heating chamber, worktable, and diaphragm assembly are all integrated on the same base, resulting in a bulky and immovable overall structure. This makes it difficult to adapt to the needs of frequent mold and material changes in a laboratory setting. Furthermore, its closed structure prevents real-time observation of key physical phenomena during the preforming process.

[0006] Patent application CN106142587A discloses a method for preforming a composite material double-bag thermal separator. The method involves encapsulating prepreg layers within a double-bag consisting of an inner and outer separator bag, and then installing the bag on a preforming device for double-bag thermal separator preforming. However, this method uses a fixed preforming device, failing to consider the needs for miniaturization and portability in laboratory settings. Furthermore, its heating and vacuum systems are controlled as a single unit, making it impossible to achieve differentiated heating in specific zones to study the impact of temperature field inhomogeneity on preforming defects.

[0007] Furthermore, the laboratory-scale double diaphragm forming machine described in the literature (Double diaphragm forming simulation for complex composite structures[J]. Composites Part A: Applied Science and Manufacturing, 2017,95: 346-358.) has a diaphragm size of 1.8m × 1.5m, and uses a pneumatic cylinder to raise and lower the diaphragm relative to the forming tool. Although this device is laboratory-scale, the diaphragm frame is fixed to the pneumatic cylinder, resulting in a fixed installation structure with poor mobility. Moreover, the use of a closed heating environment makes it impossible to observe the physical changes during the preforming process in real time, making it difficult to meet the flexible operational needs of frequent mold and material changes in the laboratory.

[0008] Therefore, a thermal insulation film preforming experimental device is needed to solve the above problems, which is of great significance. Utility Model Content

[0009] The purpose of this invention is to solve the problems existing in the prior art and to provide a thermal insulation film preforming experimental device.

[0010] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0011] A thermal diaphragm preforming experimental apparatus includes a movable heating device, a movable vacuum bed, a vacuum pump, a mold, and a diaphragm;

[0012] The portable heating device has a space for inserting a portable vacuum bed, and this space is located within the heating range of the portable heating device;

[0013] The movable vacuum bed has a cavity with an opening only at the top;

[0014] A vacuum pump is used to create the vacuum environment required for preforming within the cavity;

[0015] The mold is located inside the cavity;

[0016] The diaphragm is used to seal the opening of the cavity.

[0017] As a preferred technical solution:

[0018] As described above, the thermal insulation film preforming experimental device includes a movable heating device frame, a liftable platform, a heating lamp, and heating device rollers.

[0019] The liftable platform is installed on top of the heating device frame;

[0020] The heating lamp is installed on the lower surface of the liftable platform;

[0021] The heating device rollers are mounted at the bottom of the heating device frame.

[0022] The thermal insulation film preforming experimental device described above includes a heating device frame comprising four columns distributed at the four corners of a rectangle.

[0023] Each pair of uprights is connected by a horizontal column; all horizontal columns are installed at the same height.

[0024] The space within the movable heating device for inserting the movable vacuum bed is the space beneath all the horizontal columns within the heating device frame.

[0025] As described above, the experimental apparatus for preforming thermal insulation film has an observation window on the heating device frame, which is located above the horizontal column.

[0026] Existing thermal diaphragm preforming experimental devices mostly adopt a closed structure to ensure heating efficiency. Researchers cannot observe key physical processes such as diaphragm stretching and prepreg bonding to the mold in real time during the preforming process. Defect analysis can only be deduced from the final state of the forming. Therefore, this utility model has an observation window on the heating device frame so that researchers can observe key physical processes such as diaphragm stretching and prepreg bonding to the mold in real time during the preforming process.

[0027] As described above, in a preforming experimental device for thermal insulation film, the side wall of the heating device frame located above the horizontal column is a transparent structure.

[0028] As described above, the thermal insulation film preforming experimental device has multiple heating lamps divided into multiple groups, with each group having at least one heating lamp, and each group of heating lamps is independently controlled to turn on and off.

[0029] In existing thermal insulation film preforming devices, the heating lamp assembly is mostly controlled by a single on / off switch, resulting in a uniform and singular temperature field. There is a lack of systematic research on the impact of temperature field non-uniformity on preforming defects. However, in the actual preforming process of large structures, due to their large size and differences in mold heat capacity distribution, a complex non-uniform temperature field exists. Simple area division and differentiated heating can only control the temperature of each block, failing to reproduce the actual temperature field conditions in a small-scale laboratory setting. Therefore, to study the impact of non-uniform temperature field distribution during the preforming of large structures using a small-scale laboratory preforming device, this invention employs multiple individually controllable heating lamps, with the lamp height controlled as a whole via a lamp assembly platform, thus reproducing the actual temperature field distribution.

[0030] As described above, the thermal insulation film preforming experimental device includes a movable vacuum bed comprising a vacuum bed, a vacuum bed wall, a vacuum tube opening, and vacuum bed rollers.

[0031] The vacuum bed wall is installed above the vacuum bed, and together with the vacuum bed, they form the cavity.

[0032] The vacuum port is installed on the vacuum bed and communicates with the cavity. The vacuum port is connected to the vacuum pump through a vacuum tube.

[0033] The vacuum bed rollers are installed at the bottom of the vacuum bed.

[0034] As described above, in a thermal insulation membrane preforming experimental device, the vacuum bed wall and the vacuum bed are detachably connected, and the two can be sealed by an interference fit.

[0035] To ensure airtightness, existing thermal insulation film preforming experimental devices often use a single integrated structure between the vacuum bed wall and the vacuum bed, with a fixed height. This limits the size of the mold that can be accommodated and cannot meet the needs of studying the influence of vacuum bed depth on defects in the preforming process. To adapt to various molds, this invention adopts a structure with a vacuum bed and a detachable vacuum bed wall. Different molds can be adapted by replacing the vacuum bed wall with one of different heights, and the influence of vacuum bed depth on preforming defects can be studied.

[0036] The thermal diaphragm preforming experimental apparatus described above further includes a pressure frame, which is used to press the periphery of the diaphragm to maintain the sealed environment of the cavity.

[0037] Beneficial effects:

[0038] (1) The thermal insulation film preforming experimental device of this utility model adopts a split design. The vacuum bed and heating lamp holder are designed to be movable, which makes it easy to move in the laboratory. When the vacuum bed is pushed to an open space to place the mold material, the operating space is large and the installation is convenient. In addition, it can also be used as a trolley when changing the mold stored far away, which greatly reduces the experimental preparation time.

[0039] (2) The present invention has an observation window on the heating device frame, which can observe and record the dynamic behavior of the entire preforming process in real time, providing direct evidence for the analysis of defect formation mechanism, and overcoming the problem that the traditional closed structure cannot observe the process.

[0040] (3) This utility model uses multiple independently controlled heating lamps in conjunction with a liftable heating platform, which enables researchers to select and turn on the heating lamps in a specific area and adjust the heating distance according to experimental needs, thereby constructing a uniform or controllable gradient radiation temperature field on the surface of the prepreg, providing experimental means for studying the influence of temperature non-uniformity on the formation of defects such as wrinkles, and making up for the shortcomings of the single temperature field control means of the existing device.

[0041] (4) The present invention can flexibly adjust the height of the chamber by means of the detachable vacuum bed wall to adapt to the mold size of different thicknesses and configurations, thus effectively expanding the experimental application range of the device. Attached Figure Description

[0042] Figure 1 This is a front view of the thermal insulation film preforming experimental device of this utility model;

[0043] Figure 2 This is a perspective view of the thermal insulation film preforming experimental device of this utility model;

[0044] Figure 3 This is a perspective view of the experimental apparatus for preforming thermal insulation film of this utility model;

[0045] Figure 4 This is a front view of the portable heating device of this utility model;

[0046] Figure 5 This is a perspective view of the portable heating device of this utility model;

[0047] Figure 6 This is a schematic diagram of the movable vacuum bed of this utility model; in the figure, a is a front view of the movable vacuum bed, and b is a perspective view of the movable vacuum bed.

[0048] Figure 7 This is a top view of the pressure frame of this utility model;

[0049] In the diagram, 1-vacuum pump, 2-vacuum tube, 3-vacuum tube port, 4-vacuum bed wall, 5-vacuum bed, 6-mold, 7-prepreg, 8-diaphragm, 9-pressing frame, 11-heating device frame, 111-column, 112-horizontal column, 113-observation window, 12-heating lamp, 13-liftable platform. Detailed Implementation

[0050] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0051] A thermal insulation film preforming experimental device, such as Figures 1-7 As shown, it includes a movable heating device, a movable vacuum bed, a vacuum pump 1, a mold 6, a diaphragm 8, and a pressing frame 9;

[0052] like Figures 1-5 As shown, the movable heating device includes a heating device frame 11, a liftable platform 13, a heating lamp 12, and heating device wheels;

[0053] The heating device frame 11 includes four columns 111 distributed at the four corners of the rectangle;

[0054] Each pair of uprights 111 is connected by a horizontal column 112; all horizontal columns 112 are installed at the same height.

[0055] The heating device frame 11 is provided with an observation window 113, which is located above the horizontal column 112;

[0056] Alternatively, the side wall of the heating device frame 11 above the horizontal column 112 may be a transparent structure;

[0057] The liftable platform 13 is installed on top of the heating device frame 11;

[0058] Heating lamps 12 are installed on the lower surface of the lifting platform 13; there are multiple heating lamps 12, divided into multiple groups, with at least one heating lamp 12 in each group, and each group of heating lamps is independently controlled to turn on and off;

[0059] The heating device rollers are installed at the bottom of the heating device frame 11;

[0060] The space below all the horizontal columns 112 within the heating device frame 11 is a space for inserting a movable vacuum bed, and this space is located within the heating range of the movable heating device.

[0061] like Figures 1-3 , Figure 6 As shown, the movable vacuum bed includes a vacuum bed 5, a vacuum bed wall 4, a vacuum tube port 3, and vacuum bed rollers;

[0062] The vacuum bed wall 4 is installed above the vacuum bed 5 in a detachable manner, forming a cavity together with the vacuum bed 5;

[0063] Vacuum port 3 is installed on vacuum bed 5 and communicates with the cavity. Vacuum port 3 is connected to vacuum pump 1 through a vacuum tube 2.

[0064] Vacuum bed rollers are installed at the bottom of vacuum bed 5;

[0065] Vacuum pump 1 is used to create the vacuum environment required for preforming within the cavity;

[0066] Mold 6 is located inside the cavity and can be used to place prepreg 7;

[0067] The diaphragm 8 is used to seal the opening of the cavity;

[0068] The pressure frame 9 is used to press the periphery of the diaphragm 8.

[0069] The process of preforming the prepreg with the above-mentioned device is as follows:

[0070] The prepreg is laid layer by layer into a laminate according to the designed layup angle and size. A release film is laid on the upper and lower sides of the laminate. The selected mold is then installed in the central area of ​​the upper surface of the vacuum bed. The laminate with the release film is then laid on the pre-forming area of ​​the mold. The release film is then laid flat over the opening of the cavity, and the periphery of the release film is pressed with a pressure frame to achieve the sealing of the cavity.

[0071] After moving the vacuum bed directly under the heating device frame and fixing it, the vertical distance between the heating lamp and the upper surface of the prepreg is adjusted by the lifting platform, and the opening and closing of the heating lamps at different positions are controlled independently to form a target temperature field distribution on the surface of the prepreg. After the temperature reaches the preset target value, heat preservation is carried out.

[0072] Start the vacuum pump to bring the negative pressure inside the vacuum bed to the preset value. Under the action of negative pressure, the diaphragm is stretched downward and presses the prepreg against the mold surface. After the prepreg is completely attached to the mold shape, maintain the vacuum and pressure for a period of time to ensure sufficient compaction.

Claims

1. A preforming experimental apparatus for thermal insulation films, characterized in that, Includes a movable heating device, a movable vacuum bed, a vacuum pump (1), a mold (6), and a diaphragm (8); The portable heating device has a space for inserting a portable vacuum bed, and this space is located within the heating range of the portable heating device; The movable vacuum bed has a cavity with an opening only at the top; The vacuum pump (1) is used to create the vacuum environment required for preforming within the cavity; The mold (6) is located inside the cavity; The diaphragm (8) is used to close the opening of the cavity.

2. The experimental apparatus for preforming a thermal insulation film according to claim 1, characterized in that, The portable heating device includes a heating device frame (11), a liftable platform (13), a heating lamp (12), and heating device wheels; The liftable platform (13) is installed on top of the heating device frame (11); Heating lamp (12) is installed on the lower surface of the lifting platform (13); The heating device rollers are installed at the bottom of the heating device frame (11).

3. The experimental apparatus for preforming a thermal insulation film according to claim 2, characterized in that, The heating device frame (11) includes four columns (111) distributed at the four corners of the rectangle. Every two uprights (111) are connected by a horizontal post (112); all horizontal posts (112) are installed at the same height; The space within the movable heating device for inserting the movable vacuum bed is the space below all the horizontal columns (112) within the frame (11) of the heating device.

4. The experimental apparatus for preforming a thermal insulation film according to claim 3, characterized in that, The heating device frame (11) is provided with an observation window (113), which is located above the horizontal column (112).

5. The experimental apparatus for preforming a thermal insulation film according to claim 3, characterized in that, The side wall of the heating device frame (11) above the horizontal column (112) is a transparent structure.

6. The experimental apparatus for preforming a thermal insulation film according to claim 2, characterized in that, There are multiple heating lamps (12), which are divided into multiple groups. Each group has at least one heating lamp (12), and each group of heating lamps is independently controlled to turn on and off.

7. The experimental apparatus for preforming a thermal insulation film according to claim 1, characterized in that, The movable vacuum bed includes a vacuum bed (5), a vacuum bed wall (4), a vacuum tube port (3), and vacuum bed rollers; The vacuum bed wall (4) is installed above the vacuum bed (5) and together with the vacuum bed (5) forms the cavity; The vacuum port (3) is installed on the vacuum bed (5) and communicates with the cavity. The vacuum port (3) is connected to the vacuum pump (1) through a vacuum tube (2). The vacuum bed rollers are installed at the bottom of the vacuum bed (5).

8. The experimental apparatus for preforming a thermal insulation film according to claim 7, characterized in that, The vacuum bed wall (4) is detachably connected to the vacuum bed (5).

9. The experimental apparatus for preforming a thermal insulation film according to claim 1, characterized in that, It also includes a pressure frame (9), which is used to press the periphery of the diaphragm (8).

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