Composite blade RTM compression molding mold and molding method

Abstract

The invention relates to a composite blade RTM compression molding mold and a molding method, and belongs to the technical field of aerospace, the composite blade RTM compression molding mold comprises an upper mold plate, a lower mold plate, a first sliding block, a second sliding block, an upper pressing part and a lower pressing part, the bottom surface of the upper mold plate is provided with an upper pressing groove, and the two inner groove walls of the upper pressing groove are inclined; a lower pressing groove is formed in the top surface of the lower template, and two inner groove walls are inclined; the first sliding block and the second sliding block are oppositely arranged in the upper pressing groove and the lower pressing groove; the upper pressing part and the lower pressing part are oppositely arranged in the two forming grooves and make contact with the groove bottoms of the two forming grooves. The method comprises the following steps: firstly, inserting a propeller root paved with a lightning-protection braid into a forming cavity; and then the upper mold plate and the lower mold plate are pushed to be closed, the first sliding block and the second sliding block are driven to be close to each other, the upper pressing part and the lower pressing part are linked to be close to each other to extrude the paddle root on which the lightning-protection braid is laid, wrinkles of the lightning-protection braid due to horizontal stirring are avoided, and the qualified rate of RTM compression molding of the composite paddle is increased.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and in particular to a RTM compression molding die for a composite blade. Background Art

[0002] The lightning protection webbing on the composite blade is adhesively fixed to the working surface and the non-working surface of the blade with the axis of the blade root as the center. At the blade root, the two lightning protection webbings are respectively crimped and fixed to the metal blade root outer sleeve by a conductive metal press head and a conductive metal screw, and are interconnected. When the blade is struck by lightning, the lightning charge is transmitted and released into the equipotential body of the entire aircraft, thereby ensuring flight safety. This structure is a relatively common lightning protection technology for composite blades internationally at present.

[0003] Currently, when the composite blade is RTM compression molded, the lightning protection webbing needs to be first laid on the surface of the composite blade, and then placed in the cavity of the molding die together with the blade. Then, epoxy resin is injected into the cavity of the molding die, and finally, the temperature in the cavity of the molding die is changed to co-cure and form the lightning protection webbing and the composite blade at the same temperature. However, since the lightning protection webbing is a soft structure, when the epoxy resin is injected into the cavity of the molding die or the first slider and the second slider slide relative to each other, it is very easy to change the shape of the lightning protection webbing and cause the lightning protection webbing to wrinkle, resulting in molding failure.

[0004] Therefore, how to design a RTM compression molding die for a composite blade that is not prone to wrinkling of the lightning protection webbing is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The present invention provides a RTM compression molding die for a composite blade, which solves the technical problem of easy wrinkling of the lightning protection webbing during the molding of the existing RTM compression molding die for a composite blade.

[0006] The technical solution of the present invention for solving the above technical problems is as follows: a RTM compression molding die for a composite blade, comprising: an upper template, a lower template, a first slider, a second slider, a semi-circular upper pressing part and a semi-circular lower pressing part.

[0007] The bottom surface of the upper template is provided with an upper pressing groove, and the two inner groove walls opposite to the upper pressing groove are inclined from the groove opening to the groove bottom toward the inner direction of the upper template; the lower template is located below the lower template and its top surface is provided with a lower pressing groove, and the two inner groove walls opposite to the lower pressing groove are inclined from the groove opening to the groove bottom toward the inner direction of the lower template; the first slider and the second slider are relatively arranged in the upper pressing groove and the lower pressing groove in a direction perpendicular to the upper template, and the lower parts of the side surfaces away from each other are respectively in contact with the two inclined inner groove walls of the lower pressing groove, and the upper parts of the side surfaces away from each other are respectively in contact with the upper The two inclined inner groove walls of the pressing groove are in contact so as to approach or move away from each other as the upper template and the lower template move up and down. The sides of the first slider and the second slider that are close to each other are provided with molding grooves, and the two molding grooves form a molding cavity after the first slider and the second slider are close to each other; the upper pressing part and the lower pressing part are both arranged in the two molding grooves relative to each other in a direction perpendicular to the upper template and are in contact with the groove bottoms of the two molding grooves, and the upper pressing part and the lower pressing part approach or move away from each other as the first slider and the second slider slide.

[0008] The beneficial effects of the present invention are: changing the structure of the traditional RTM compression molding mold for composite blades, first inserting the blade root covered with lightning protection webbing into the molding cavity formed by the first slider and the second slider; then pushing the upper mold plate and the lower mold plate to close the mold, driving the first slider and the second slider to slide along the inclined direction of the inner groove wall of the upper pressing groove and the inclined direction of the inner groove wall of the lower pressing groove and approach each other, and linking the upper pressing part and the lower pressing part to move up and down to squeeze the blade root covered with lightning protection webbing, and then, under the premise that the first slider and the second slider cannot be removed, the movement direction of the upper pressing part and the lower pressing part is adjusted to the up and down direction, thereby avoiding horizontal movement of the lightning protection webbing wrinkles and improving the qualified rate of the RTM compression molding of the composite blades.

[0009] Based on the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, the bottoms of the two forming grooves are each provided with a semi-annular groove; semi-annular sliders are fixed on the outer annular walls of the upper pressing part and the lower pressing part, and the two semi-annular sliders are slidably connected in the two semi-annular grooves.

[0011] A further beneficial effect of adopting the above method is: by using a semi-ring slider fixed on the upper pressure part and the lower pressure part and slidingly connected in the semi-ring groove at the bottom of the forming groove, the sliding direction of the upper pressure part and the lower pressure part can be limited, thereby avoiding the circumferential shaking of the upper pressure part and the lower pressure part along the vertical semi-ring groove.

[0012] Furthermore, it also includes a positioning pin, and the bottoms of the two semi-ring grooves that are close to each other are each provided with a half hole, and the two opposite half holes can constitute a positioning pin hole; the two semi-ring sliders are each provided with a fixing hole, and the two fixing holes are respectively arranged opposite to the two positioning pin holes; there are two positioning pins, and one end of each of the positioning pins is respectively inserted into the two fixing holes, and the other end is respectively inserted into the opposite positioning pin hole, and the diameter of the positioning pin is smaller than the diameter of the positioning pin hole to limit the circumferential shaking of the upper pressure part or the lower pressure part along the perpendicular semi-ring groove and prevent the positioning pin from limiting the circumferential sliding of the upper pressure part or the lower pressure part along the semi-ring groove.

[0013] A further beneficial effect of adopting the above method is: since the extrusion distance between the upper pressure part and the lower pressure part is 0.5mm, the diameter of the positioning pin is smaller than the diameter of the positioning pin hole, which can not only limit the circumferential shaking of the upper pressure part or the lower pressure part along the vertical semi-annular groove, but also prevent the positioning pin from limiting the circumferential sliding of the upper pressure part or the lower pressure part along the semi-annular groove.

[0014] Furthermore, the first slider and the second slider are both semi-hexagonal structures.

[0015] In addition, a composite blade RTM compression molding method is provided, which specifically comprises the following steps:

[0016] S1, first apply a pre-tightening force to the first slider and the second slider, use the first slider and the second slider to approach each other, and then put the first slider and the second slider approaching each other into the lower pressing groove and the upper pressing groove, at this time, the first slider and the second slider are both at a predetermined distance from the bottom of the lower pressing groove and the bottom of the upper pressing groove;

[0017] S2, laying a lightning protection webbing on the surface of the blade and the blade root, and then inserting the blade root with the lightning protection webbing into the molding cavity formed between the first slider and the second slider;

[0018] S3, push the upper mold plate and the lower mold plate up and down to close the mold, at the same time, the first slider and the second slider will slide along the inclined direction of the inner groove wall of the upper pressing groove and the inclined direction of the inner groove wall of the lower pressing groove and approach each other, and link the upper pressing part and the lower pressing part to slide up and down to squeeze the paddle root covered with the lightning protection belt;

[0019] S4, injecting annular resin into the molding cavity;

[0020] S5. According to the temperature-viscosity curve, the temperatures of the first template and the second template are adjusted to change the molding temperature in the molding cavity so as to mold the lightning protection ribbon and the propeller root at the same temperature and co-curing.

[0021] The above method has the further beneficial effect that before the lightning protection webbing and the propeller root are molded together for co-curing at the same temperature, the upper and lower pressure parts are moved up and down to extrude the lightning protection webbing, which can prevent the lightning protection webbing from wrinkling and improve the molding efficiency and molding qualification rate of the lightning protection webbing. Brief Description of the Drawings

[0022] Figure 1 Fig. is a three-dimensional structural schematic diagram of a composite blade RTM compression molding die of the present invention;

[0023] Figure 2 Fig. is a three-dimensional structural schematic diagram of a lower template, a first slider, an upper pressing part and a lower pressing part in a composite blade RTM compression molding die of the present invention;

[0024] Figure 3 is Figure 2 A partial enlarged structural schematic diagram at position A.

[0025] In the drawings, the list of components represented by each reference numeral is as follows:

[0026] 1. upper template, 2. lower template, 21. lower pressing groove, 3. first slider, 31. forming groove, 311. semi-circular groove, 4. upper pressing part, 5. lower pressing part, 6. semi-circular slider, 7. positioning pin. Detailed Embodiment

[0027] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0028] As Figure 1 shown, a composite blade RTM compression molding die includes: an upper template 1, a lower template 2, a first slider 3, a second slider, a semi-circular upper pressing part 4 and a semi-circular lower pressing part 5,

[0029] The bottom surface of the upper template 1 is provided with an upper pressing groove, and both inner groove walls of the upper pressing groove opposite to each other are inclined from the groove opening to the groove bottom towards the inside of the upper template 1; the lower template 2 is located below the lower template 2, and its top surface is provided with a lower pressing groove 21. Both inner groove walls of the lower pressing groove 21 opposite to each other are inclined from the groove opening to the groove bottom towards the inside of the lower template 2; the first slider 3 and the second slider are both arranged oppositely in the upper pressing groove and the lower pressing groove 21 along the direction perpendicular to the upper template 1, and the lower parts of their mutually remote side surfaces are respectively in contact with the two inclined inner groove walls of the lower pressing groove 21, and the upper parts of their mutually remote side surfaces are respectively in contact with the two inclined inner groove walls of the upper pressing groove, so as to approach or move away from each other as the upper template 1 and the lower template 2 move up and down. Forming grooves 31 are provided on the mutually approaching side surfaces of the first slider 3 and the second slider, and the two forming grooves 31 form a forming cavity after the first slider 3 and the second slider approach each other; the upper pressing part 4 and the lower pressing part 5 are both oppositely placed in the two forming grooves 31 along the direction perpendicular to the upper template 1 and are both in contact with the groove bottoms of the two forming grooves 31, and the upper pressing part 4 and the lower pressing part 5 approach or move away from each other as the first slider 3 and the second slider slide.

[0030] In some specific embodiments, semi-circular grooves 311 may be provided at the bottoms of both of the two forming grooves 31; semi-circular sliding blocks 6 are fixedly provided on the outer circumferential walls of the upper pressing portion 4 and the lower pressing portion 5, and the two semi-circular sliding blocks 6 are slidably connected in the two semi-circular grooves 311.

[0031] In some specific embodiments, a positioning pin 7 may further be included. Semi-holes are provided at the bottoms of the two semi-circular grooves 311 close to each other, and the two opposite semi-holes can form a positioning pin hole; fixing holes are provided on both of the two semi-circular sliding blocks 6 and the two fixing holes are arranged opposite to the two positioning pin holes respectively; there are two positioning pins 7 and one ends of them are respectively inserted and fixed in the two fixing holes, and the other ends are respectively inserted into the opposite positioning pin holes. The diameter of the positioning pin 7 is smaller than the diameter of the positioning pin hole to limit the upper pressing portion 4 or the lower pressing portion 5 from swaying along the circumferential direction perpendicular to the semi-circular groove 311 and prevent the positioning pin from restricting the upper pressing portion 4 or the lower pressing portion 5 from sliding along the circumferential direction of the semi-circular groove 311.

[0032] In some specific embodiments, both the first sliding block 3 and the second sliding block may be of a semi-hexagonal prism structure.

[0033] In addition, a method for RTM molding of a composite blade is provided, including the following steps:

[0034] S1. First, apply a pre-tightening force to the first sliding block 3 and the second sliding block, use the first sliding block 3 and the second sliding block to approach each other, and then place the approaching first sliding block 3 and second sliding block into the lower pressing groove 21 and the upper pressing groove. At this time, both the first sliding block 3 and the second sliding block are at a predetermined distance from the bottom of the lower pressing groove 21 and the bottom of the upper pressing groove.

[0035] S2. Lay a lightning protection woven tape on the surfaces of the blade and the blade root, and then insert the blade root with the lightning protection woven tape inserted between the first sliding block 3 and the second sliding block to form a molding cavity.

[0036] S3. Push the upper template 1 and the lower template 2 to close the mold. At the same time, the first sliding block 3 and the second sliding block will slide along the inclined directions of the inner groove walls of the upper pressing groove and the inclined directions of the inner groove walls of the lower pressing groove 21 and approach each other, and drive the upper pressing die and the lower pressing portion 5 to slide up and down to squeeze the blade root with the lightning protection woven tape.

[0037] S4. Inject annular resin into the molding cavity.

[0038] S5. According to the temperature-viscosity curve, adjust the temperatures of the first template and the second template, change the molding temperature in the molding cavity, so as to co-cure and form the lightning protection woven tape and the blade root at the same temperature.

[0039] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A composite blade RTM compression molding die, It is characterized in that include: An upper template (1) and a lower template (2), wherein the bottom surface of the upper template (1) is provided with an upper pressing groove, and the two inner groove walls opposite to the upper pressing groove are inclined from the groove opening to the groove bottom toward the interior of the upper template (1); the lower template (2) is located below the lower template (2) and the top surface thereof is provided with a lower pressing groove (21), and the two inner groove walls opposite to the lower pressing groove (21) are inclined from the groove opening to the groove bottom toward the interior of the lower template (2); A first slider (3) and a second slider, wherein the first slider (3) and the second slider are arranged relatively in the upper pressing groove and the lower pressing groove (21) along a direction perpendicular to the upper template (1), and the lower parts of the mutually distant side surfaces are respectively in contact with the two inclined inner groove walls of the lower pressing groove (21), and the upper parts of the mutually distant side surfaces are respectively in contact with the two inclined inner groove walls of the upper pressing groove, so as to approach or move away from each other as the upper template (1) and the lower template (2) move up and down, and the mutually adjacent sides of the first slider (3) and the second slider are both provided with molding grooves (31), and the two molding grooves (31) form a molding cavity after the first slider (3) and the second slider are adjacent to each other; A semi-annular upper pressing portion (4) and a semi-annular lower pressing portion (5), wherein the upper pressing portion (4) and the lower pressing portion (5) are both arranged in the two molding grooves (31) in a direction perpendicular to the upper mold plate (1) and are in contact with the bottoms of the two molding grooves (31); the upper pressing portion (4) and the lower pressing portion (5) approach or move away from each other as the first slider (3) and the second slider slide.

2. A composite blade RTM compression molding die according to claim 1, It is characterized in that The bottoms of the two forming grooves (31) are each provided with a semi-annular groove (311); semi-annular sliders (6) are fixed on the outer annular walls of the upper pressing portion (4) and the lower pressing portion (5), and the two semi-annular sliders (6) are slidably connected in the two semi-annular grooves (311).

3. A composite blade RTM compression molding die according to claim 2, It is characterized in that It also includes a positioning pin (7), and the bottoms of the two semi-annular grooves (311) close to each other are each provided with a half hole, and the two opposite half holes can constitute a positioning pin hole; the two semi-annular sliders (6) are each provided with a fixing hole, and the two fixing holes are respectively arranged opposite to the two positioning pin holes; there are two positioning pins (7), and one end of each of the positioning pins is respectively inserted into the two fixing holes, and the other end is respectively inserted into the opposite positioning pin hole, and the diameter of the positioning pin (7) is smaller than the diameter of the positioning pin hole to limit the upper pressure part (4) or the lower pressure part (5) from shaking along the circumferential direction perpendicular to the semi-annular groove (311) and prevent the positioning pin from limiting the upper pressure part (4) or the lower pressure part (5) from sliding along the circumferential direction of the semi-annular groove (311).

4. The RTM compression molding die for a composite blade according to claim 1, It is characterized in that The first sliding block (3) and the second sliding block both have a semi-hexagonal structure.

5. A method for RTM molding of a composite blade, characterized in that, it includes the RTM molding die for the composite blade according to any one of claims 1-4, and the specific steps are as follows: S1. First, apply a pre-tightening force to the first slider (3) and the second slider, use the first slider (3) and the second slider to approach each other, and then place the approaching first slider (3) and second slider into the lower pressing groove (21) and the upper pressing groove. At this time, both the first slider (3) and the second slider are at a predetermined distance from the bottom of the lower pressing groove (21) and the bottom of the upper pressing groove; S2. Lay a lightning protection woven tape on the surfaces of the blade and the blade root, and then insert the blade root with the lightning protection woven tape inserted between the first slider (3) and the second slider to form a molding cavity; S3. Push the upper template (1) and the lower template (2) to close the mold up and down. At the same time, the first slider (3) and the second slider will slide along the inclined directions of the inner groove walls of the upper pressing groove and the inclined direction of the inner groove wall of the lower pressing groove (21) to approach each other, and drive the upper pressing part and the lower pressing part (5) to slide up and down to squeeze the blade root with the lightning protection woven tape; S4. Inject annular resin into the molding cavity; S5. According to the temperature-viscosity curve, adjust the temperatures of the first template and the second template, change the molding temperature in the molding cavity, so as to co-cure the lightning protection woven tape and the blade root at the same temperature during mold closing.

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