Ring frame piece forming mold and method

Abstract

The invention discloses a ring frame piece forming mold and method.The ring frame piece forming mold comprises a mold body and a pressing block assembly, two intersecting forming grooves are formed in the mold body and intersect to form an 8-shaped structure, pasting grooves are formed in the two sides of the mold body, and the pressing block assembly is arranged on the mold body; the length direction of the pasting groove is parallel to the arrangement direction of the two forming grooves, the two ends of the pasting groove communicate with the two forming grooves correspondingly, protrusions between the pasting groove and the two forming grooves are protruding blocks, and the pressing block assembly can be matched with the forming grooves and the pasting groove to extrude the prepreg, so that prepressing and curing of the annular frame part are achieved. The ring frame piece forming method is implemented on a ring frame piece forming mold, and when the prepreg is laid, fibers of the prepreg with different fiber angles in a designated area are continuous, so that the continuity of a prepreg laying layer and the accuracy of the fiber angles are ensured to the greatest extent, and the bearing capacity of the prepared ring frame piece is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of composite material load-bearing structural component forming, and specifically relates to a ring frame component forming mold and method. Background Art

[0002] In order to meet the increasing demand for lightweight spacecraft, all-composite load-bearing cabins are increasingly being used. Among them, the ring frame composite structural parts, as the annular components of the cabin, are important main load-bearing structures that can support the cabin and diffuse concentrated loads. The cabin of a certain model product contains an 8-shaped ring frame, which requires the molding process to adopt the lay-up-autoclave process. The specific structure of the ring frame is as follows: Figure 1 shown.

[0003] Ring-frame composite structural parts are mainly subjected to bending and axial shear loads. Bending failure is the main failure mode of this type of structural parts. Therefore, during the manufacturing process, the design of the fiber direction determines the strength and performance of the structure.

[0004] The ring frame is prepared by the lay-up-autoclave molding process. The prepreg materials of the parts are stacked in the mold according to the designed order and layers, and then hot-pressed and cured.

[0005] However, ring-frame composite structural parts have non-expandable curved surfaces. When laying prepreg, the fiber angle will change with the structural form. That is, when laying prepreg, bending the prepreg will cause its fiber angle to deviate from the design direction, making it difficult to achieve consistency between the fiber angle and the structural design direction at each laying angle during the prepreg laying process. Therefore, it is impossible to accurately control the direction and distribution of the fibers, which in turn affects the mechanical properties of the part structure. Summary of the invention

[0006] In order to solve the above technical problems, the present application provides a ring frame forming mold on the one hand to solve the technical problem that it is difficult to achieve consistency between the fiber angle and the structural design direction at each layup angle in the prepreg layup process in the prior art, and therefore the fiber angle and distribution cannot be accurately controlled.

[0007] The technical solution adopted to achieve the purpose of this application is:

[0008] A ring frame forming die, comprising:

[0009] A mold body, used for carrying the prepreg for preparing the ring frame, the mold body is provided with two intersecting molding grooves, the cross-section of the molding groove is circular, the two molding grooves intersect to form an "8"-shaped structure, both sides of the mold body are provided with pasting grooves, the length direction of the pasting groove is parallel to the arrangement direction of the two molding grooves, and the two ends of the pasting groove are respectively connected with the two molding grooves, and the protrusion between the pasting groove and the two molding grooves is a convex block;

[0010] A pressing block assembly is used to cooperate with the molding groove and the pasting groove to extrude the prepreg; wherein, when the prepreg is laid on the mold body, the pressing block assembly is adhered to the side wall of the molding groove and the bottom wall of the molding groove and the side wall of the pasting groove and the bottom wall of the pasting groove, and is assembled in the molding groove and the pasting groove to pre-press and shape the prepreg.

[0011] In order to better realize the present application, further optimization is made in the above structure. A groove is provided on the top of the protrusion, and a demolding module matching the shape of the groove is provided in the groove. A demolding bolt is provided at the bottom of the mold body, and a threaded hole is provided at the bottom of the groove. The abutting end of the demolding bolt can pass through the threaded hole and abut against the demolding module.

[0012] In order to better realize the present application, further optimization is made in the above structure, wherein the pressing block assembly includes a first pressing block, a second pressing block and a conformable skin;

[0013] There are multiple first pressing blocks, which are arranged along the circumference of the forming groove, and a force-bearing inclined surface is provided on the side of the first pressing block away from the side wall of the forming groove, the upper edge of the force-bearing inclined surface is connected to the top surface of the first pressing block, the lower edge of the force-bearing inclined surface is connected to the bottom surface of the first pressing block, and the upper edge of the force-bearing inclined surface is inclined toward the extrusion surface of the first pressing block;

[0014] The side wall of the second pressing block is provided with an extrusion inclined surface matching the force-bearing inclined surface;

[0015] The conformable skin can be arranged along the circumference of the forming groove or the extension direction of the pasting groove, and can extrude prepreg in cooperation with the side wall and the bottom wall of the forming groove or the side wall and the bottom wall of the pasting groove.

[0016] In order to better implement the present application, the above structure is further optimized, wherein a locking piece is provided on the second pressing block, and a connecting end of the locking piece passes through the second pressing block and is connected to the mold body;

[0017] A positioning protrusion is arranged at the bottom of the forming groove, and a positioning hole matching the positioning protrusion is arranged on the second pressing block.

[0018] On the other hand, the present application provides a ring frame forming method, the method is implemented using the above-mentioned ring frame forming mold, and the method includes the following steps:

[0019] Primer: using mesh cloth to lay on the mold body to form a bottom layer, the bottom layer covers the molding grooves, bumps and pasting grooves;

[0020] Laying layers, using a mesh cloth folded in half and laid on the bottom layer at the intersection of two molding grooves to form a partition, so that the two molding grooves are isolated from each other; two thickened layers are arranged in the molding groove, and the thickened layers extend from the side wall of the molding groove away from the partition to the position where the molding groove and the two pasting grooves are connected, and the two thickened layers are symmetrically arranged with respect to the arrangement direction of the two molding grooves, and the thickness of the thickened layer at one end close to the connection between the molding groove and the pasting groove is greater than the thickness of the thickened layer at one end away from the connection between the molding groove and the pasting groove; the prepreg is laid layer by layer on the bottom layer at different fiber angles, and it is ensured that the fibers of the prepreg in the designated area are continuous under different fiber angles; when the number of layers of the prepreg reaches the designated number of layers, a pressing block assembly is assembled in the molding groove and the pasting groove for pre-pressing;

[0021] Curing: when the number of prepreg layers reaches the designed number, the pressing block assembly is assembled in the forming groove and the pasting groove for curing;

[0022] Demolding process, taking out the solidified primary finished product from the mold body, and processing the primary finished product to obtain the ring frame part.

[0023] In order to better realize the present application, further optimization is made in the above method. When laying the layers, the prepreg is laid on the bottom layer in sequence with fiber angles of 0°, 45°, 90° and -45°, and the angle of the fiber direction is the angle between the length direction of the fiber in the prepreg and the arrangement direction of the two molding grooves.

[0024] In order to better realize the present application, the above method is further optimized, the molding groove is divided into A1 area, A2 area, A3 area, A4 area, A5 area and A6 area along its circumferential direction, the A1 area is located at one end of the two molding grooves away from each other, the A2 area, the A3 area, the A4 area, the A5 area and the A6 area are arranged in a clockwise direction, the A4 area is located at the intersection of the two molding grooves, and the two ends of the pasting groove are respectively connected to the A2 area and the A6 area of ​​the two molding grooves; the prepreg is laid layer by layer on the bottom layer at different fiber angles, and the fiber continuity of the prepreg in the specified area under different fiber angles is ensured to refer to:

[0025] When laying the prepreg with a fiber angle of 0°, the prepreg at the intersection of the upper end surface of the protrusion and the side wall of the molding groove and at the intersection of the side wall of the molding groove connecting the protrusion and the bottom wall of the molding groove remain continuous;

[0026] When laying prepreg with fiber angles of 45° and -45°, the prepreg remains continuous at all locations where folding is required;

[0027] When laying the prepreg with a fiber angle of 90 degrees, the prepreg at the intersection of the upper end surface of the protrusion and the side wall of the groove remains continuous.

[0028] In order to better realize the present application, further optimization is made in the above method, and the two ends of the pasting groove are respectively connected with the A2 area and the A6 area of ​​the two forming grooves;

[0029] Before laying the layers, thickening layers are arranged in the A2 area and the A6 area so that the end of the thickening layer away from the A1 area can be connected with the prepreg laid in the molding groove and the prepreg laid in the pasting groove; wherein the thickening layer is laid by 60 layers of prepreg, and the fiber angles of the prepregs for laying the thickening layer are laid in sequence of 0°, 45°, 90° and -45°, and the length of every 4 layers of prepreg decreases once, so that the thickness of the end of the thickening layer away from the A1 area is greater than the thickness of the end of the thickening layer close to the A1 area.

[0030] In order to better realize the present application, the above method is further optimized. During the plying process, every time 5 layers of the prepreg are laid, the pressing block assembly is used to extrude the prepreg in the forming groove and the pasting groove for a normal temperature prepressing. During the normal temperature prepressing, the vacuum pressure is -0.09MPa to -0.1MPa, and the prepressing time is 20min to 30min.

[0031] When laying the 10th and 35th layers, use a pressing block assembly to extrude the prepreg in the forming groove and the pasting groove and put it into an oven for oven-vacuum prepressing; during oven-vacuum prepressing, the vacuum pressure in the oven is -0.09Mpa to -0.1Mpa, the prepressing temperature is 130±5℃, and the prepressing time is 2h;

[0032] When the number of laid layers reaches the designed number of layers, a pressing block assembly is used to extrude the prepreg in the molding groove and the pasting groove and put into the autoclave for autoclave-vacuum prepressing; during the autoclave-vacuum prepressing, the vacuum pressure in the autoclave is -0.09MPa~-0.1MPa, the external pressure is 0.6Mpa, the prepressing temperature is 130±5℃, and the prepressing time is 2h.

[0033] In order to better realize the present application, further optimization is made in the above method. During curing, a pressing block assembly is used to extrude the prepreg in the molding groove and the pasting groove and put it into a curing tank for curing; the vacuum pressure in the curing tank is -0.09MPa to -0.1MPa, and the external pressure is 0.6Mpa; during the curing process, the temperature in the curing tank is adjusted according to the following steps:

[0034] Raise the temperature in the curing tank to 90°C and maintain for 1 hour;

[0035] Raise the temperature in the curing tank to 180°C and maintain for 3 hours;

[0036] Raise the temperature in the curing tank to 200°C and maintain for 2 hours.

[0037] Raise the temperature in the curing tank to 240°C and maintain for 4 hours;

[0038] When the temperature in the curing tank naturally drops below 60°C, the ring frame molding mold is taken out.

[0039] It can be seen from the above technical scheme that the ring frame molding mold and method provided in the present application can ensure the continuity of the prepreg ply and the accuracy of the fiber angle to the greatest extent while ensuring the overall external dimensions of the ring frame, thereby improving the load-bearing capacity of the prepared ring frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of the 8-shaped ring frame recorded in the background technology;

[0041] Figure 2 A schematic structural diagram of a ring frame forming die provided in this application;

[0042] Figure 3 An exploded view of a ring frame forming die provided in the present application;

[0043] Figure 4 A schematic structural diagram of a mold body in a ring frame molding mold provided in the present application;

[0044] Figure 5 for Figure 4 A partial enlarged view of point C in the middle;

[0045] Figure 6 A schematic structural diagram of a pressing block assembly in a ring frame forming mold provided in the present application.

[0046] Description of reference numerals:

[0047] 1-mold body, 11-molding groove, 12-sticking groove, 13-bump, 131-stripping module;

[0048] 2-pressing block assembly, 21-first pressing block, 22-second pressing block, 23-conformable skin. DETAILED DESCRIPTION

[0049] In order to enable technicians in the technical field to which the present application belongs to understand the present application more clearly, the technical solution of the present application is described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0050] In the embodiments of the present application, Figures 2 to 6 As shown, the ring frame forming mold includes a mold body 1 and a pressing block assembly 2; wherein,

[0051] The mold body 1 is used to carry the prepreg for preparing the ring frame. Two intersecting molding grooves 11 are arranged on the mold body 1. The cross-section of the molding groove 11 is circular. The two molding grooves 11 intersect to form an "8"-shaped structure. Both sides of the mold body 1 are provided with pasting grooves 12. The length direction of the pasting groove 12 is parallel to the arrangement direction of the two molding grooves 11, and the two ends of the pasting groove 12 are respectively connected with the two molding grooves 11, so that the prepreg laid on the side wall of the pasting groove 12 can be connected with the prepreg laid on the side wall of the molding groove 11. The protrusion between the pasting groove 12 and the two molding grooves 11 is a bump 13;

[0052] The pressing block assembly 2 is used to cooperate with the forming groove 11 and the pasting groove 12 to extrude the prepreg so as to achieve shaping of the prepreg.

[0053] In some embodiments, a groove is provided on the top of the protrusion 13, see Figure 4 The sink is provided with a stripping module 131 matching the shape of the sink, the bottom of the mold body 1 is provided with a stripping bolt, the bottom of the sink is provided with a threaded hole, and the abutting end of the stripping bolt can pass through the threaded hole and abut against the stripping module 131;

[0054] After the prepreg is cured, the staff can install the demoulding bolts at the threaded holes and tighten the demoulding bolts so that the abutting ends of the demoulding bolts abut against the demoulding module 131, and push the demoulding module 131 away from the sink, so as to push the preliminary finished product out of the mold body 1 and realize the demoulding of the preliminary finished product.

[0055] It should be noted that when laying the prepreg, the stripping module 131 is embedded in the sink, and the top surface of the stripping module 131 coincides with the top surface of the bump 13 to ensure that the prepreg can be laid flat on the top surfaces of the bump 13 and the stripping module 131 .

[0056] In some embodiments, the above-mentioned pressing block assembly 2 includes a first pressing block 21, a second pressing block 22 and a conformal skin 23, see Figure 6 ;in,

[0057] There are multiple first pressing blocks 21, which are arranged along the circumference of the forming groove 11, and a force-bearing inclined surface is provided on the side of the first pressing block 21 away from the side wall of the forming groove 11, the upper edge of the force-bearing inclined surface is connected to the top surface of the first pressing block 21, the lower edge of the force-bearing inclined surface is connected to the bottom surface of the first pressing block 21, the upper edge of the force-bearing inclined surface is inclined toward the extrusion surface of the first pressing block 21, and the force-bearing inclined surface and the extrusion surface of the first pressing block 21 are arranged on both sides of the first pressing block 21 opposite to each other;

[0058] The side wall of the second pressing block 22 is provided with an extrusion inclined surface matching the force-bearing inclined surface. When the second pressing block 22 is extruded into the molding groove 11, the extrusion inclined surface on the second pressing block 22 can cooperate with the force-bearing inclined surface on the first pressing block 21, and the first pressing block 21 is extruded obliquely downward of the molding groove 11, so that the extrusion surface and the bottom surface of the first pressing block 21 can cooperate with the side wall and the bottom wall of the molding groove 11 to extrude the prepreg, thereby completing the pre-pressing and curing of the ring frame member with an "L"-shaped cross-section;

[0059] The conformable skin 23 can be arranged along the circumference of the molding groove 11 (not shown in the figure) or the extension direction of the pasting groove 12, and can cooperate with the side walls of the molding groove 11 and the bottom wall of the molding groove 11 or the side walls of the pasting groove 12 and the bottom wall of the pasting groove 12 to extrude the prepreg.

[0060] In some embodiments, a locking piece is provided on the second pressing block 22, and the connecting end of the locking piece passes through the second pressing block 22 and is connected to the mold body 1; wherein the locking piece is a bolt; when the second pressing block 22 needs to be pressed, the locking piece can be passed through the second pressing block 22 and connected to the mold body 1, and then the locking piece is tightened so that the nut end of the locking piece can drive the second pressing block 22 to be squeezed into the molding groove 11; and when the locking piece stops being twisted, the locking piece can maintain the position of the second pressing block 22, providing a stable squeezing force for the first pressing block 21;

[0061] A positioning protrusion is provided at the bottom of the above-mentioned molding groove 11, and a positioning hole matching the positioning protrusion is provided on the second pressing block 22 to fix the moving direction of the second pressing block 22, thereby ensuring that the second pressing block 22 can simultaneously squeeze multiple first pressing blocks 21 arranged circumferentially along the molding groove 11 toward the side wall of the molding groove 11.

[0062] Based on the above-mentioned ring frame forming mold, the present application also provides a ring frame forming method, which is implemented by the above-mentioned ring frame forming mold, and the method includes the following steps:

[0063] Primer: Use mesh cloth to lay on the mold body 1 to form a bottom layer, which covers the molding groove 11, the protrusion 13 and the pasting groove 12;

[0064] Laying: using a mesh cloth folded in half and laid on the bottom layer at the intersection of the two forming grooves 11 to form a partition, so that the two forming grooves 11 are isolated from each other;

[0065] Two thickening layers are arranged in the forming groove 11, and the thickening layers extend from the side wall of the forming groove 11 away from the partition to the position where the forming groove 11 is connected with the two pasting grooves 12. The two thickening layers are symmetrically arranged with respect to the arrangement direction of the two forming grooves 11, see Figure 4 and Figure 5, and the thickness of the thickened layer at one end close to the connection between the forming groove 11 and the pasting groove 12 is greater than the thickness of the thickened layer at one end away from the connection between the forming groove 11 and the pasting groove 12, so as to fill the defect (deformation) at the connection between the forming groove 11 and the pasting groove 12, so that the radius of the side wall of the forming groove 11, the side of the thickened layer away from the forming groove 11 and the partition are equal;

[0066] The prepreg is laid on the bottom layer layer by layer at different fiber angles, and the fibers of the prepreg in the designated area are ensured to be continuous under different fiber angles; when the number of prepreg layers reaches the designated number, the pressing block assembly 2 is assembled in the forming groove 11 and the pasting groove 12 for pre-pressing;

[0067] Curing: When the number of prepreg layers reaches the designed number of layers, the pressing block assembly 2 is assembled in the forming groove 11 and the pasting groove 12 for curing;

[0068] Demolding process, using the demolding module 131 to remove the cured primary product from the mold body 1, and process the height, long axis flange thickness (prepreg corresponding to the groove 12) and inner circle size (prepreg corresponding to the molding groove 11) of the primary product to obtain a ring frame part.

[0069] In some embodiments, when laying the layers, the prepreg is laid on the bottom layer in sequence with fiber angles of 0°, 45°, 90° and -45°, and the fiber direction angle is the angle between the length direction of the fiber in the prepreg and the arrangement direction of the two molding grooves 11.

[0070] In some embodiments, the forming groove 11 is divided into an A1 area, an A2 area, an A3 area, an A4 area, an A5 area and an A6 area along its circumferential direction. Figure 4 The first pressing block 21 is also provided with six corresponding to the A1 area, the A2 area, the A3 area, the A4 area, the A5 area and the A6 area, see Figure 2 , area A1 is located at one end of the two molding grooves 11 away from each other, area A2, area A3, area A4, area A5 and area A6 are arranged in a clockwise direction, area A4 is located at the intersection of the two molding grooves 11, area A2, area A3 and area A5 and area A6 are symmetrically arranged with respect to the arrangement direction of the two molding grooves 11, and both ends of the sticking groove 12 are respectively connected with area A2 and area A6 of the two molding grooves 11;

[0071] The above-mentioned laying of the prepreg on the substrate layer by layer at different fiber angles and ensuring the fiber continuity of the prepreg at the designated area under different fiber angles refers to:

[0072] When laying the prepreg with a fiber angle of 0°, the prepreg at the intersection of the upper end surface of the protrusion 13 and the side wall of the molding groove 11 and at the intersection of the side wall of the molding groove 11 and the protrusion 13 and the bottom wall of the molding groove 11 remain continuous;

[0073] When laying prepregs with fiber angles of 45° and -45°, the prepregs remain continuous at all positions that need to be folded, such as: the intersection of the upper end surface of the protrusion 13 and the side wall of the pasting groove 12, the intersection of the upper end surface of the protrusion 13 and the side wall of the molding groove 11, and the intersection of the side wall of the molding groove 11 and the bottom wall of the molding groove 11;

[0074] When laying the prepreg with a fiber angle of 90°, the prepreg at the intersection of the upper end surface of the protrusion 13 and the side wall of the pasting groove 12 remains continuous;

[0075] The adjacent prepregs are butt-jointed, and the gap is controlled within 0-1mm. During the layering process, the prepregs must be effectively fitted together without wrinkles or hollows. If wrinkles or hollows occur, manual intervention is required, that is, the wrinkles or hollows are cut with a tool so that the wrinkles or hollows can be flatly fitted on the mold body 1. The fibers must not be cut during the process to ensure the continuity of the prepreg.

[0076] It is worth noting that the above-mentioned prepreg is a strip structure. When laying prepregs with fiber angles of 0°45°, -45° and 90°, multiple prepregs are laid in sequence along a direction perpendicular to the limiting angle.

[0077] In some embodiments, the two ends of the above-mentioned pasting groove 12 are respectively connected to the A2 area and the A6 area of ​​the two forming grooves 11;

[0078] Before laying, thickening layers are arranged in the A2 area and the A6 area, so that the end of the thickening layer away from the A1 area can be butted against the prepreg laid in the forming groove 11 and the prepreg laid in the pasting groove 12; wherein,

[0079] The thickening layer is formed by paving 60 layers of prepreg, and the fiber angles of the prepreg for paving the thickening layer are laid in sequence of 0°, 45°, 90° and -45°, and the length of every 4 layers of prepreg decreases once, so that the thickness of the end of the thickening layer away from the A1 area is greater than the thickness of the end of the thickening layer close to the A1 area. The thicker end of the thickening layer can be connected to the prepreg at the pasting groove 12 to ensure the structural stability of the formed ring frame.

[0080] In some embodiments, during the layering process, every time 5 layers of prepreg are laid, the conformable skin 23 is used to extrude into the forming groove 11 and the pasting groove 12 for a normal temperature pre-pressing; during the normal temperature pre-pressing, the vacuum pressure is -0.09MPa to -0.1MPa, and the pre-pressing time is 20min to 30min;

[0081] When laying the 10th and 35th layers, the first pressing block 21 and the second pressing block 22 are pressed on the prepreg in the forming groove 11 and put into the oven for oven-vacuum prepressing; during the oven-vacuum prepressing, the vacuum pressure in the oven is -0.09Mpa to -0.1Mpa, the prepressing temperature is 130±5°C, and the prepressing time is 2h;

[0082] When the number of laid layers reaches the designed number of layers, the first pressing block 21 and the second pressing block 22 are squeezed on the prepreg in the molding groove 11 and put into the autoclave for autoclave-vacuum prepressing; during the autoclave-vacuum prepressing, the vacuum pressure in the autoclave is -0.09MPa~-0.1MPa, the external pressure is 0.6Mpa, the prepressing temperature is 130±5℃, and the prepressing time is 2h.

[0083] In some embodiments, during curing, the A4 area uses the first pressing block 21, and the prepregs in other areas of the molding groove 11 and the pasting groove 12 are pressed onto the prepregs using the conformable skin 23 and placed in a curing tank for curing; the vacuum pressure in the curing tank is -0.09MPa to -0.1MPa, and the external pressure is 0.6MPa; during the curing process, the temperature in the curing tank is adjusted according to the following steps:

[0084] Raise the temperature in the curing tank to 90°C and maintain for 1 hour;

[0085] Raise the temperature in the curing tank to 180°C and maintain for 3 hours;

[0086] Raise the temperature in the curing tank to 200°C and maintain for 2 hours.

[0087] Raise the temperature in the curing tank to 240°C and maintain for 4 hours;

[0088] When the temperature in the curing tank naturally drops below 60°C, the ring frame molding mold is taken out.

[0089] Through the above embodiments, the present application has the following beneficial effects or advantages:

[0090] The ring frame molding mold and method can ensure the continuity of the prepreg layer and the accuracy of the fiber angle to the greatest extent while ensuring the overall external dimensions of the ring frame, thereby improving the load-bearing capacity of the prepared ring frame.

[0091] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0092] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A ring frame forming die, characterized in that: include: A mold body (1) is used to carry a prepreg for preparing the ring frame member. The mold body (1) is provided with two intersecting molding grooves (11). The cross-section of the molding groove (11) is circular. The two molding grooves (11) intersect to form an "8"-shaped structure. Both sides of the mold body (1) are provided with pasting grooves (12). The length direction of the pasting groove (12) is parallel to the arrangement direction of the two molding grooves (11), and the two ends of the pasting groove (12) are respectively connected to the two molding grooves (11). The protrusion between the pasting groove (12) and the two molding grooves (11) is a bump (13); and, A pressing block assembly (2) is used to cooperate with the molding groove (11) and the pasting groove (12) to extrude the prepreg; wherein, when the prepreg is laid on the mold body (1), the pressing block assembly (2) is pasted to the side wall of the molding groove (11) and the bottom wall of the molding groove (11) as well as the side wall of the pasting groove (12) and the bottom wall of the pasting groove (12) to pre-press and shape the prepreg.

2. The ring frame forming mold according to claim 1, characterized in that: A recessed groove is provided at the top of the protrusion (13), a demoulding module (131) matching the shape of the recessed groove is provided in the recessed groove, a demoulding bolt is provided at the bottom of the mold body (1), a threaded hole is provided at the bottom of the recessed groove, and the abutting end of the demoulding bolt can pass through the threaded hole to abut against the demoulding module (131).

3. The ring frame forming die according to claim 1, characterized in that: The pressing block assembly (2) comprises a first pressing block (21), a second pressing block (22) and a conformable skin (23); The number of the first pressing blocks (21) is multiple, and the multiple first pressing blocks (21) are arranged along the circumference of the forming groove (11), and a force-bearing inclined surface is provided on the side of the first pressing block (21) away from the side wall of the forming groove (11), the upper edge of the force-bearing inclined surface is connected to the top surface of the first pressing block (21), the lower edge of the force-bearing inclined surface is connected to the bottom surface of the first pressing block (21), and the upper edge of the force-bearing inclined surface is inclined toward the extrusion surface of the first pressing block (21); The side wall of the second pressing block (22) is provided with an extrusion inclined surface matching the force-bearing inclined surface; The conformable skin (23) can be arranged along the circumference of the molding groove (11) or the extension direction of the pasting groove (12), and can cooperate with the side wall of the molding groove (11) and the bottom wall of the molding groove (11) or the side wall of the pasting groove (12) and the bottom wall of the pasting groove (12) to extrude the prepreg.

4. The ring frame forming die according to claim 3, characterized in that: The second pressing block (22) is provided with a locking piece, and the connecting end of the locking piece passes through the second pressing block (22) and is connected to the mold body (1); A positioning protrusion is provided at the bottom of the molding groove (11), and a positioning hole matching the positioning protrusion is provided on the second pressing block (22).

5. A ring frame forming method, characterized in that: The method is implemented by using the ring frame forming mold described in any one of 1 to 4, and the method comprises the following steps: Primer: using a mesh cloth to be laid on the mold body (1) to form a bottom layer, wherein the bottom layer covers the molding groove (11), the convex block (13) and the pasting groove (12); Laying layers, using a mesh cloth folded in half and laid on the bottom layer at the intersection of two molding grooves (11) to form a partition, so that the two molding grooves (11) are isolated from each other; two thickening layers are arranged in the molding groove (11), and the thickening layers extend from the side wall of the molding groove (11) away from the partition to the position where the molding groove (11) and the two pasting grooves (12) are connected, and the two thickening layers are symmetrically arranged with respect to the arrangement direction of the two molding grooves (11), and the thickness of one end of the thickening layer close to the connection between the molding groove (11) and the pasting groove (12) is greater than the thickness of one end of the thickening layer away from the connection between the molding groove (11) and the pasting groove (12); laying the prepreg layer by layer on the bottom layer at different fiber angles, and ensuring that the fibers of the prepreg in the specified area are continuous under different fiber angles; when the number of layers of the prepreg reaches the specified number of layers, assembling the pressing block assembly (2) in the molding groove (11) and the pasting groove (12) for pre-pressing; Curing: when the number of prepreg layers reaches the designed number of layers, a pressing block assembly (2) is assembled in the molding groove (11) and the pasting groove (12) for curing; Demolding process, taking out the solidified primary finished product from the mold body (1), and processing the primary finished product to obtain a ring frame part.

6. The ring frame forming method according to claim 5, characterized in that: During plying, the prepreg is laid on the bottom layer in sequence at fiber angles of 0°, 45°, 90° and -45°, and the fiber direction angle is the angle between the length direction of the fibers in the prepreg and the arrangement direction of the two molding grooves (11).

7. The ring frame forming method according to claim 6, characterized in that: The molding groove (11) is divided into an A1 area, an A2 area, an A3 area, an A4 area, an A5 area and an A6 area along its circumferential direction, the A1 area is located at one end of the two molding grooves (11) away from each other, the A2 area, the A3 area, the A4 area, the A5 area and the A6 area are arranged in sequence in a clockwise direction, the A4 area is located at the intersection of the two molding grooves (11), and the two ends of the pasting groove (12) are respectively connected to the A2 area and the A6 area of ​​the two molding grooves (11); laying the prepreg layer by layer on the bottom layer at different fiber angles, and ensuring that the fibers of the prepreg in the designated area at different fiber angles are continuous refers to: When laying prepreg with a fiber angle of 0°, the prepreg at the intersection of the upper end surface of the protrusion (13) and the side wall of the molding groove (11) and at the intersection of the side wall of the molding groove (11) connected to the protrusion (13) and the bottom wall of the molding groove (11) remain continuous; When laying prepreg with fiber angles of 45° and -45°, the prepreg remains continuous at all locations where folding is required; When laying prepreg with a fiber angle of 90 degrees, the prepreg at the intersection of the upper end surface of the protrusion (13) and the side wall of the groove (12) remains continuous.

8. The ring frame forming method according to claim 7, characterized in that: The two ends of the pasting groove (12) are respectively connected to the A2 area and the A6 area of ​​the two forming grooves (11); Before ply laying, thickening layers are arranged in the A2 area and the A6 area, so that the end of the thickening layer away from the A1 area can be connected with the prepreg laid in the forming groove (11) and the prepreg laid in the pasting groove (12); wherein the thickening layer is formed by laying 60 layers of prepreg, and the fiber angles of the prepregs laying the thickening layer are laid in sequence of 0°, 45°, 90° and -45°, and the length of every 4 layers of prepreg decreases once, so that the thickness of the end of the thickening layer away from the A1 area is greater than the thickness of the end of the thickening layer close to the A1 area.

9. The ring frame forming method according to claim 5, characterized in that: During the plying process, after laying five layers of the prepreg, the pressing block assembly (2) is used to extrude the prepreg into the forming groove (11) and the pasting groove (12) for a prepressing at room temperature; during the prepressing at room temperature, the vacuum pressure is -0.09MPa to -0.1MPa, and the prepressing time is 20min to 30min; When laying the 10th and 35th layers, a pressing block assembly (2) is used to press the prepreg in the forming groove (11) and the pasting groove (12) and put into an oven for oven-vacuum prepressing; during the oven-vacuum prepressing, the vacuum pressure in the oven is -0.09Mpa to -0.1Mpa, the prepressing temperature is 130±5°C, and the prepressing time is 2h; When the number of laid layers reaches the designed number of layers, a pressing block assembly (2) is used to extrude the prepreg in the forming groove (11) and the pasting groove (12) and put it into an autoclave for autoclave-vacuum prepressing; during the autoclave-vacuum prepressing, the vacuum pressure in the autoclave is -0.09MPa to -0.1MPa, the external pressure is 0.6Mpa, the prepressing temperature is 130±5°C, and the prepressing time is 2h.

10. The ring frame forming method according to claim 5, characterized in that: During curing, a pressing block assembly (2) is used to press the prepreg in the molding groove (11) and the pasting groove (12) and put into a curing tank for curing; the vacuum pressure in the curing tank is -0.09MPa to -0.1MPa, and the external pressure is 0.6MPa; during the curing process, the temperature in the curing tank is adjusted according to the following steps: Raise the temperature in the curing tank to 90°C and maintain for 1 hour; Raise the temperature in the curing tank to 180°C and maintain for 3 hours; Raise the temperature in the curing tank to 200°C and maintain for 2 hours. Raise the temperature in the curing tank to 240°C and maintain for 4 hours; When the temperature in the curing tank naturally drops below 60°C, the ring frame molding mold is taken out.

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