A flexible pressure roller with controllable hardness and its use method

Abstract

The present invention relates to a flexible pressure roller with controllable hardness, comprising a flexible rubber layer, a thermosensitive rubber layer, an airbag layer, a metal core layer, a mandrel, an air intake pipe, a pressure sensor and a heating coil; wherein the mandrel, the metal core layer, the airbag layer, the thermosensitive rubber layer and the flexible rubber layer are sequentially fitted and sleeved from the inside to the outside; the air intake pipe is connected to the airbag layer and is used to inflate the airbag layer, the heating coil is wound around the outside of the thermosensitive rubber layer, and the pressure sensor is arranged in the flexible rubber layer. The present invention also relates to a method for using a flexible pressure roller with controllable hardness. The purpose of the flexible pressure roller with controllable hardness and the method for using the same is to solve the problem of difficulty in fitting and compacting prepreg layers during the automatic laying process of variable curvature parts.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to a flexible pressure roller with controllable hardness and a use method thereof. Background Art

[0002] The widespread application of composite parts in military and civilian fields such as aerospace and high-speed rail is inseparable from the strong support of automated manufacturing technology, especially automatic tape laying technology and automatic wire laying technology (collectively referred to as automatic placement technology). Automatic placement technology can not only effectively reduce manufacturing costs and improve manufacturing efficiency, but also accurately control the placement process parameters, which can effectively ensure the reliability and stability of composite parts. However, the current automatic placement technology has strict requirements on the structural surfaces and molds of composite materials. Due to the complex local surface structure of parts with variable curvature, it is difficult to fit and compact the layers after the prepreg is automatically laid, and the cured parts are prone to internal quality defects such as delamination and porosity.

[0003] Therefore, the inventor provides a flexible pressure roller with controllable hardness and a method for using the same. Summary of the invention

[0004] (1) Technical issues to be solved

[0005] The embodiment of the present invention provides a flexible pressure roller with controllable hardness and a method for using the same, which solves the technical problem of difficulty in laminating and compacting prepreg layers during the automatic placement of variable curvature parts.

[0006] (2) Technical solution

[0007] The present invention provides a flexible pressure roller with controllable hardness, comprising a flexible rubber layer, a heat-sensitive rubber layer, an airbag layer, a metal core layer, a core shaft, an air intake pipe, a pressure sensor and a heating coil; wherein:

[0008] The core shaft, the metal core layer, the airbag layer, the heat-sensitive rubber layer and the flexible rubber layer are sequentially fitted and sleeved from the inside to the outside;

[0009] The air inlet pipe is connected to the airbag layer and is used to inflate the airbag layer. The heating coil is wound around the outside of the heat-sensitive rubber layer. The pressure sensor is arranged in the flexible rubber layer.

[0010] Furthermore, the airbag layer has airbag struts in it, and the airbag struts are distributed along the length direction thereof and connect the inner layer and the outer layer of the airbag layer.

[0011] Furthermore, the flexible pressure roller with controllable hardness also includes a pressure-controlled air source system, and the pressure-controlled air source system is used to regulate the air intake volume of the air intake pipe.

[0012] Furthermore, the flexible pressure roller with controllable hardness also includes a temperature control system, and the temperature control system is used to adjust the temperature of the heating coil.

[0013] Furthermore, the thermosensitive rubber layer is made of thermosensitive rubber material, and its heat-resistant temperature is higher than 200°C.

[0014] Furthermore, the heating coil is in a single-ring form, and a plurality of the heating coils are sequentially and spaced apart in a ring-shaped manner and wound around the outer surface of the heat-sensitive rubber layer.

[0015] Furthermore, the heat-resistant temperature of the heating coil is higher than 200°C.

[0016] Furthermore, the distance between two adjacent heating coils is 5 mm to 70 mm.

[0017] The present invention also provides a method for using a flexible pressure roller with controllable hardness, comprising the following steps:

[0018] Installing the flexible pressure roller on the automatic placement equipment;

[0019] Inflate the airbag layer through an air inlet pipe so that the airbag layer swells under the action of air pressure, and close the air inlet pipe after the pressure sensor reaches a predetermined pressure reading;

[0020] The automatic placement equipment places the prepreg on the variable curvature part mold according to a predetermined program;

[0021] The flexible pressing roller rolls and compacts the prepreg;

[0022] The heating coil starts to heat up in the area where the pressure sensor reading changes, and the local hardness of the thermosensitive rubber layer decreases;

[0023] When the readings of the pressure sensors at different positions tend to be consistent, the heating of the heating coil is stopped;

[0024] The flexible pressing roller rolls and compacts the prepreg again;

[0025] After the prepreg is laid, the gas in the airbag layer is released through the air inlet pipe, and the flexible pressing roller is removed from the automatic laying equipment.

[0026] Furthermore, the internal gas pressure of the airbag layer ranges from 0.1 MPa to 0.4 MPa.

[0027] (3) Beneficial effects

[0028] In summary, the present invention heats the thermosensitive rubber layer by means of the heating coil, and the local hardness of the thermosensitive rubber layer is reduced, and the flexible pressure roller with controllable hardness is locally deformed to completely fit the surface of the variable curvature workpiece, thereby applying uniform pressure to the surface of the laid prepreg material to ensure that the prepreg layers are fitted and compacted. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 It is a structural schematic diagram of a flexible pressure roller with controllable hardness provided by an embodiment of the present invention;

[0031] Figure 2 is a cross-sectional schematic diagram of a flexible pressure roller with controllable hardness provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic cross-sectional view of an airbag layer of a flexible pressure roller with controllable hardness provided by an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of the application of the flexible pressure roller provided by an embodiment of the present invention in a variable curvature mold;

[0034] Figure 5 It is a flow chart of a method for using a flexible pressure roller with controllable hardness provided in an embodiment of the present invention.

[0035] In the figure:

[0036] 1-flexible rubber layer; 2-thermosensitive rubber layer; 3-airbag layer; 4-metal core layer; 5-core shaft; 6-intake pipe; 7-pressure sensor; 8-heating coil; 9-airbag support; 10-pressure control air source system; 11-temperature control system; 12-variable curvature part mold; 13-preg. DETAILED DESCRIPTION

[0037] The following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments, and covers any modification, replacement and improvement of parts, components and connection modes without departing from the spirit of the present invention.

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] Figure 1 is a schematic diagram of the structure of a flexible pressure roller with controllable hardness provided by an embodiment of the present invention, such as Figure 1-2As shown, the flexible pressure roller may include a flexible rubber layer 1, a heat-sensitive rubber layer 2, an airbag layer 3, a metal core layer 4, a core shaft 5, an air intake pipe 6, a pressure sensor 7 and a heating coil 8; wherein,

[0040] The core shaft 5, the metal core layer 4, the airbag layer 3, the thermosensitive rubber layer 2 and the flexible rubber layer 1 are sequentially fitted and sleeved from the inside to the outside; the air intake pipe 6 is connected to the airbag layer 3 and is used to inflate the airbag layer 3, the heating coil 8 is wound around the outside of the thermosensitive rubber layer 2, and the pressure sensor 7 is arranged in the flexible rubber layer 1.

[0041] In the above embodiment, the local hardness of the thermosensitive rubber layer 2 is reduced by heating through the heating coil 8, and the flexible pressure roller with controllable hardness is locally deformed to completely fit the surface of the variable curvature workpiece, and uniform pressure is applied to the surface of the laid prepreg 13 to ensure that the prepreg 13 is laid and compacted between layers.

[0042] Specifically, Figure 1 As shown, a plurality of pressure sensors 7 are sequentially spaced apart along the axial direction of the flexible rubber layer 1 , so that the external (prepreg) pressure borne by different regions of the flexible rubber layer 1 can be obtained in real time.

[0043] In some optional embodiments, such as Figure 3 As shown, the airbag layer 3 has airbag struts 9, which are distributed along its length and connect the inner and outer layers of the airbag layer 3. Specifically, a plurality of airbag struts 9 are sequentially arranged at intervals in the airbag layer 3, and such an arrangement can support the airbag layer 3 more stably.

[0044] In some optional embodiments, such as Figure 4 As shown, the flexible pressure roller with controllable hardness also includes a pressure-controlled air source system 10, which is used to control the air intake of the air intake pipe 6. The pressure-controlled air source system 10 can adjust the air intake of the air intake pipe 6 in real time according to the actual needs of the preparation, so that the air pressure control is more accurate.

[0045] In some optional embodiments, such as Figure 4 As shown, the flexible pressure roller with controllable hardness also includes a temperature control system 11, which is used to control the temperature of the heating coil 8. The temperature control system 11 can adjust the working temperature of the heating coil 8 in real time according to the actual needs of the preparation, so that the temperature control is more accurate.

[0046] In some optional embodiments, the thermosensitive rubber layer 2 is made of thermosensitive rubber material, and its heat-resistant temperature is higher than 200°C. The Shore hardness of the thermosensitive rubber at room temperature is about 60A, and the hardness of the thermosensitive rubber decreases with increasing temperature. The temperature range is from room temperature to 100°C, the Shore hardness varies between 60A and 20A, and the thickness is 3mm to 15mm. Such thickness selection can ensure that the thermosensitive rubber layer has sufficient thickness to support sufficient deformation, so that the flexible pressure roller with controllable hardness can fully fit the surface prepreg layer of the variable curvature part, thereby applying uniform pressure to the surface of the variable curvature part.

[0047] In some optional embodiments, such as Figure 1 As shown, the heating coil 8 is in a single ring form, and a plurality of heating coils 8 are sequentially wound around the outer surface of the heat-sensitive rubber layer 2. Specifically, each heating coil 8 is a parallel circuit, and the single-ring heating coils are connected in parallel, and each heating coil can be heated separately, so that the local hardness of the flexible pressure roller can be controlled, rather than the entire roller becoming softer or harder.

[0048] In some optional embodiments, the spacing between two adjacent heating coils 8 is 5 mm to 70 mm. The spacing of the heating coils is selected according to the structural characteristics of the variable curvature workpiece to be compacted, so that after the heating coils are heated, the flexible pressing roller can completely fit the surface of the variable curvature workpiece, so as to apply uniform pressure to the surface of the variable curvature workpiece.

[0049] The width of a single heating coil 8 is 1 mm to 10 mm. The width of the heating coil is selected according to the structural characteristics of the variable curvature workpiece to be compacted, so that after the heating coil is heated, the flexible pressing roller can completely fit the surface of the variable curvature workpiece, so as to apply uniform pressure to the surface of the variable curvature workpiece.

[0050] Figure 5 1 is a flow chart of a method for using a flexible pressure roller with controllable hardness provided by an embodiment of the present invention. The method may include the following steps:

[0051] S100, installing the flexible pressure roller on the automatic placement equipment;

[0052] S200, inflating the airbag layer through the air intake pipe so that the airbag layer swells under the action of air pressure, and closing the air intake pipe after the pressure sensor reaches a predetermined pressure reading;

[0053] S300, the automatic placement equipment places the prepreg on the variable curvature part mold according to a predetermined program;

[0054] S400, flexible roller rolling and compacting prepreg;

[0055] S500, the heating coil in the area where the pressure sensor reading changes starts to heat up, and the local hardness of the thermosensitive rubber layer decreases;

[0056] S600, when the readings of the pressure sensors at different positions tend to be consistent, the heating of the heating coil is stopped;

[0057] S700, the flexible pressing roller rolls and compacts the prepreg again;

[0058] S800. After the prepreg is laid, the gas in the airbag layer is released through the air inlet pipe, and the flexible pressure roller is removed from the automatic laying equipment.

[0059] In the above embodiment, the airbag layer 3 is firstly inflated through the air inlet pipe 6, and the inflation pressure is adjusted by the pressure control system 10 to control the pressure sensor pressure reading to 0.2 MPa.

[0060] like Figure 4 As shown, the automatic laying equipment lays the prepreg 13 on the variable curvature workpiece mold 12 according to a predetermined program, and the flexible pressure roller with controllable hardness rolls and compacts the prepreg 13; due to the change in the surface curvature of the prepreg 13, the pressure readings of different pressure sensors 7 in the flexible pressure roller with controllable hardness change to 0.25MPa~0.30MPa. The heating coil 8 starts to heat the area where the reading of the pressure sensor 7 changes, the local hardness of the thermosensitive rubber layer 2 decreases, and the readings of all pressure sensors 7 are controlled between 0.25MPa and 0.26MPa. The annular heating coil 8 stops heating. The flexible pressure roller with controllable hardness rolls and compacts the prepreg 13 at the curvature change position of the workpiece. After the prepreg 13 is laid, the gas in the airbag layer 3 is released through the air inlet pipe 6.

[0061] According to the display reading of the pressure sensor 7, the heating coil 8 can perform local heating to adjust the hardness of the thermosensitive rubber layer 2, thereby making the surface hardness of the pressure roller uniform and stable.

[0062] The airbag layer 3 used in the present invention controls the air intake through the indication of the pressure sensor 7, adjusts the overall hardness of the flexible roller with controllable hardness to match the viscosity of the applied prepreg and the thickness of the prepreg; adjusts the local hardness of the flexible roller with controllable hardness through the heating coil 8, so that the flexible roller with controllable hardness is completely fitted with the surface prepreg layer of the variable curvature workpiece. The method has the characteristics of simple operation and adaptability to various complex surfaces, and can effectively avoid internal quality risks such as delamination and porosity of variable curvature workpieces during the automatic molding process.

[0063] In some optional embodiments, in step S200, the internal gas pressure of the airbag layer is in the range of 0.1MPa to 0.4MPa. Specifically, if the internal gas pressure of the airbag layer is too low, it cannot effectively support the surface flexible rubber layer and the heat-sensitive rubber layer. If the internal gas pressure of the airbag layer is too high, the surface rigidity of the flexible rubber layer and the heat-sensitive rubber layer is too large, and the flexible rubber layer is still difficult to completely adhere to the surface of the variable curvature workpiece after being heated and softened.

[0064] It should be clear that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. In addition, for the sake of brevity, a detailed description of known methods and technologies is omitted here.

[0065] The above are only embodiments of the present application and are not limited to the present application. For those skilled in the art, the present application may have various changes and variations without departing from the scope of the present invention. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method for using a flexible pressure roller with controllable hardness, characterized in that: The flexible pressure roller comprises a flexible rubber layer (1), a thermosensitive rubber layer (2), an airbag layer (3), a metal core layer (4), a core shaft (5), an air intake pipe (6), a pressure sensor (7) and a heating coil (8); wherein the core shaft (5), the metal core layer (4), the airbag layer (3), the thermosensitive rubber layer (2) and the flexible rubber layer (1) are sequentially fitted and sleeved from the inside to the outside; the air intake pipe (6) is connected to the airbag layer (3) and is used to inflate the airbag layer (3); the heating coil (8) is wound around the outside of the thermosensitive rubber layer (2); and the pressure sensor (7) is arranged in the flexible rubber layer (1); the method comprises the following steps: Installing the flexible pressure roller on the automatic placement equipment; Inflate the airbag layer through the air inlet pipe so that the airbag layer swells under the action of air pressure, and close the air inlet pipe after the pressure sensor reaches a predetermined pressure reading; The automatic placement equipment places the prepreg on the variable curvature workpiece mold according to a predetermined program; The flexible pressing roller rolls and compacts the prepreg; The heating coil starts to heat up in the area where the pressure sensor reading changes, and the local hardness of the thermosensitive rubber layer decreases; When the readings of the pressure sensors at different positions tend to be consistent, the heating of the heating coil is stopped; The flexible pressing roller rolls and compacts the prepreg again; After the prepreg is laid, the gas in the airbag layer is released through the air inlet pipe, and the flexible pressing roller is removed from the automatic laying equipment; The flexible pressure roller further comprises a temperature control system (11), wherein the temperature control system (11) is used to adjust the temperature of the heating coil (8); the thermosensitive rubber layer (2) is made of a thermosensitive rubber material having a heat resistance temperature higher than 200° C. The heating coil (8) is in the form of a single ring, and a plurality of the heating coils (8) are sequentially and spaced in an annular direction and wound around the outer surface of the thermosensitive rubber layer (2).

2. The method for using the flexible pressure roller with controllable hardness according to claim 1, characterized in that: The internal gas pressure of the airbag layer ranges from 0.1 MPa to 0.4 MPa.

3. The method for using the flexible pressure roller with controllable hardness according to claim 1, characterized in that: The airbag layer (3) has airbag struts (9) in it, and the airbag struts (9) are distributed along its length direction and connect the inner and outer layers of the airbag layer (3).

4. The method for using the flexible pressure roller with controllable hardness according to claim 1, characterized in that: The flexible pressure roller further comprises a pressure-controlled air source system (10), wherein the pressure-controlled air source system (10) is used to regulate the air intake volume of the air intake pipe (6).

5. The method for using the flexible pressure roller with controllable hardness according to claim 1, characterized in that: The heat-resistant temperature of the heating coil (8) is higher than 200°C.

6. The method for using the flexible pressure roller with controllable hardness according to claim 1, characterized in that: The distance between two adjacent heating coils (8) is 5 mm to 70 mm.

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