Method for adhesive forming of a fiber-wound housing skirt

Abstract

The application discloses a kind of fibre winding shell skirt bonding forming method, winding core mould is formed according to the profile of fibre winding shell inner thermal insulation layer after machining, inner thermal insulation layer is pasted on winding core mould and is polished, according to the winding mode of spiral winding and ring winding alternation, skirt inner winding is carried out on the surface of inner thermal insulation layer to obtain un-solidified shell, process stress release groove, rubber buffer layer is bonded on skirt inner surface and outer surface and solidified, skirt is installed to the skirt bonding area of un-solidified shell, and the buffer layer of skirt outer surface is bound skirt and ring winding, after ring winding, hoist to solidification furnace is carried out to rotate solidification.The bonding forming method of the application improves the bonding quality of upper skirt, and process reliability is strong, and is suitable for wet upper skirt fibre winding shell.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of solid rocket engine shell forming, and particularly relates to a fiber winding shell skirt bonding forming method. BACKGROUND

[0002] The composite material shell connecting skirt is mainly used for connecting the engine and the interstage section or connecting other cabin section components of the rocket. During the flight of the solid rocket engine, the huge thrust generated by the engine is transmitted to the projectile body through the connecting skirt to push the whole projectile to fly. The connecting skirt is an important force receiving component of the rocket, and has to bear the combined action of axial pressure, bending moment and other loads during the flight of the rocket, and the stress condition is complex. How to improve the structural efficiency of the connecting skirt is of great significance to the improvement of the overall performance of the engine and even the whole rocket. A large number of existing studies have made parameter research, performance analysis and failure analysis on the connecting part of the composite material shell skirt of the solid rocket engine, but none of them has shown what kind of process method can improve the bonding quality of the skirt part. SUMMARY

[0003] The present application belongs to the technical field of solid rocket engine shell forming, and particularly relates to a fiber winding shell skirt bonding forming method.

[0004] To achieve the above-mentioned purpose, the present application provides a fiber winding shell skirt bonding forming method comprising the following steps:

[0005] S1) Selecting a winding core mold according to the length-diameter ratio of the fiber winding shell, and machining the winding core mold according to the inner type surface of the inner thermal insulation layer of the fiber winding shell after the winding core mold is formed;

[0006] S2) Pasting the inner thermal insulation layer on the winding core mold, and polishing the skirt bonding area on the surface of the inner thermal insulation layer by using an automatic polisher;

[0007] S3) Carrying out skirt inner winding on the surface of the inner thermal insulation layer in a winding mode of alternately winding in a spiral and in a hoop direction to obtain an uncured shell;

[0008] S4) Processing a stress release groove on the skirt and at a bonding area bonded with the uncured shell;

[0009] S5) Uniformly brushing nitrile phenolic adhesive on each bonding surface of the inner and outer surfaces of the skirt and the rubber buffer layer, bonding the rubber buffer layer to the inner and outer surfaces of the skirt, and then vacuumizing and curing;

[0010] S6) Uniformly brushing nitrile phenolic adhesive on the surface of the buffer layer of the inner surface of the skirt, and installing the skirt to the skirt bonding area of the uncured shell;

[0011] S7) Uniformly brushing nitrile phenolic adhesive on the surface of the buffer layer of the outer surface of the skirt, and binding and hoop winding the skirt;

[0012] S8) Laying a layer of glue absorbing cloth on the surface of the uncured shell at the end of the hoop winding, then using glass fiber yarn to hoop winding the surface of the uncured shell, after the hoop winding is finished, hoisting into the curing oven for rotary curing.

[0013] Further, the winding core mold is a gypsum core mold or a sand core mold.

[0014] Further, in step S3), the hoop winding before the last spiral winding is used to control the shell interference amount, and then the last spiral winding is performed; the specific method of interference amount control is:

[0015] First, confirm the theoretically required size: set the skirt adhesive starting point position as (0, (D1-d-2h-0.5) / 2) and the skirt tip position as (L, (D2-d-2h+2) / 2), wherein D1 is the inner diameter of the skirt adhesive starting point, d is the increment of the diameter of one spiral winding uncured shell, D2 is the inner diameter of the skirt tip, h is the thickness of the rubber buffer layer, and L is the axial length from the skirt adhesive starting point to the skirt tip; then, bring the two points of the skirt adhesive starting point and the skirt tip into the equation Y=kX+b to calculate the values of k and b, and then take a diameter value Y n as a measurement point, i.e., X n = 20-40n, n=1, 2, 3…, until L-X n ≤ 20mm, every diameter Y n tolerance is ±0.3mm;

[0016] First, measure the outer diameter of the uncured shell before the last spiral winding, and confirm the thickness a that needs to be supplemented for each measurement point by comparing the actual measurement value with the theoretically required size; then divide the thickness a by the increment b of the single-layer hoop winding thickness to obtain the number c1 of hoop layers that need to be supplemented for each measurement point, and perform hoop winding from the position of the maximum supplemented hoop layer on the side of the barrel segment 10-20mm to the skirt adhesive starting point direction, to the position of the minimum supplemented hoop layer on the side 10-20mm, and then perform reverse hoop winding to the position of the minimum supplemented hoop layer on the other side 10-20mm; if the maximum supplemented hoop layer is the skirt tip, then perform hoop winding from the position of the skirt tip 10-20mm, and continue to supplement according to the above requirements, so that the actual number of supplemented hoop layers for each position in the first time meets c1 or c1-1; after the first supplement is completed, measure the outer diameter of the uncured shell for the second time, and obtain the number c2 of hoop layers that need to be supplemented for the second time by using the above-mentioned hoop layer calculation method, and perform the above-mentioned supplementing operation, so that the actual number of supplemented hoop layers for the second time meets c2 or c2-1; finally, measure the outer diameter of the uncured shell for the third time, and obtain the number c3 of hoop layers that need to be supplemented for the third time by using the above-mentioned hoop layer calculation method, and only need to perform in-situ hoop winding on the position of the corresponding number c3 of supplemented hoop layers.

[0017] Further, in the step S4), the stress release groove length extends from the skirt bonding starting point to the skirt tip.

[0018] Further, in the step S4), the stress release groove number is 24-48, and the width is 2-5 mm.

[0019] Further, in the step S5), the curing is performed at 60-70 DEG C for 2-6 h, and the vacuum degree is -90 to -110 KPa.

[0020] Further, in the step S7), the specific process of binding the skirt and circumferentially winding is as follows: 5-7 layers of the skirt binding layer are circumferentially wound back and forth from the front equator position to the front skirt tip; after the skirt binding is completed, the continuous yarn is wound to the surface of the uncured shell and the skirt tip triangular area is leveled, and then the rear skirt is circumferentially wound, and finally the circumferential winding of the outer skirt is completed.

[0021] Further, in the step S7), the starting point of the skirt binding is wound back and forth from the equator to the skirt tip, and the single yarn tension is 50-70 N.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] 1) The present application adopts the shell outer diameter size calculation scheme and the shell outer diameter supplementary winding method, which not only ensures that the interference amount of the upper skirt area is from negative to positive transition from the equator to the skirt tip, increases the upper skirt area angle, improves the adhesion strength of the skirt and the shell, but also effectively ensures the straightness of the upper skirt area, which can effectively improve the adhesion quality of the skirt and the shell, and prevent the adhesion of the skirt and the shell interface.

[0024] 2) The adhesion forming method of the present application improves the adhesion quality of the upper skirt, and the process has high reliability, and is suitable for wet upper skirt fiber winding shell. DETAILED DESCRIPTION

[0025] The present application will be further described below in conjunction with specific examples.

[0026] The fiber winding shell skirt adhesion forming method of the present application comprises the following steps:

[0027] S1) Select a winding core mold according to the length-diameter ratio of the fiber winding shell, and machine the winding core mold according to the inner type surface of the inner thermal insulation layer after the winding core mold is formed; the winding core mold can be selected from gypsum core mold or sand core mold.

[0028] S2) Paste the inner thermal insulation layer on the winding core mold, and polish the skirt bonding area on the surface of the inner thermal insulation layer with an automatic polisher to ensure the roundness and straightness of the skirt bonding area, which avoids the quality problems such as uneven force on the skirt and skirt adhesion area arching caused by the non-circular shell in the subsequent winding process.

[0029] S3) The skirt is spirally wound on the surface of the inner thermal insulation layer in an alternating winding mode of spiral winding and circumferential winding to obtain an uncured shell, and the shell interference amount control is performed before the last spiral winding, and then the last spiral winding is performed.

[0030] The specific method of interference amount control is as follows: first, the theoretically required size is confirmed: the skirt bonding starting point position is set as (0, (D1-d-2h-0.5) / 2), and the skirt tip position is set as (L, (D2-d-2h+2) / 2), wherein D1 is the inner diameter of the skirt bonding starting point, d is the increment of the diameter of one spiral wound uncured shell, D2 is the inner diameter of the skirt tip, h is the thickness of the rubber buffer layer, and L is the axial length of the skirt bonding starting point to the skirt tip; then the two points of the skirt bonding starting point and the skirt tip are brought into the equation Y=kX+b to calculate the values of k and b, and then a diameter value Y is taken every 20-40 mm from the skirt bonding starting point n as the measurement point, i.e. X n =20-40n, n=1, 2, 3……, until L-X n ≤20mm, and the tolerance of each diameter Y n is ±0.3mm.

[0031] The outer diameter of the uncured shell before the last spiral winding is measured for the first time, and the difference between the actual measured value and the theoretically required size is compared to confirm the required thickness a of each measurement point to be supplemented; then the thickness a of each measurement point to be supplemented is divided by the thickness increment b of a single layer of circumferential winding, and the maximum number of circumferential layers c1 to be supplemented at each measurement point is obtained by taking the integer part; starting from the position of the maximum number of circumferential layers on the side of the cylinder segment 10-20mm, the circumferential winding is performed towards the skirt bonding starting point, and then the reverse circumferential winding is performed to pass through the position of the minimum number of circumferential layers on the other side 10-20mm; if the maximum number of circumferential layers is the skirt tip, then the circumferential winding is performed to pass through the skirt tip 10-20mm, and then the circumferential winding is continued from the position as the starting point according to the above requirements, so that the actual number of circumferential layers supplemented at each position in the first time satisfies c1 or c1-1; after the first time of supplementing, the outer diameter of the uncured shell is measured for the second time, and the number of circumferential layers c2 to be supplemented in the second time is obtained by taking the above-mentioned circumferential layer number calculation method, and the circumferential winding is performed according to the above-mentioned supplementing operation, so that the actual number of circumferential layers supplemented in the second time satisfies c2 or c2-1; finally, the outer diameter of the uncured shell is measured for the third time, and the number of circumferential layers c3 to be supplemented in the third time is obtained by taking the above-mentioned circumferential layer number calculation method, and only the circumferential layer number c3 corresponding to the supplementing position needs to be wound in place.

[0032] The theory shell outer diameter requirement size calculation scheme and shell outer diameter supplement method, relative to traditional fiber winding shell, adopt general calculation method to obtain the last spiral winding front outer diameter requirement size of the upper skirt area of the shell, that is, ensure the interference amount of the upper skirt area to be from negative to positive transition, and ensure the straightness of the upper skirt area; continuous ring winding is used for supplement, which ensures the outer shape surface roundness of the upper skirt area, avoids the high and low points in the upper skirt area, and the above method effectively improves the bonding quality of the skirt and the shell and prevents the interface debonding of the skirt and the shell.

[0033] S4) stress release grooves are processed on the skirt and located at the bonding area bonded with the uncured shell, the stress release groove length extends from the bonding starting point of the skirt to the skirt tip, which can effectively prevent the debonding at the starting position of the bonding area; the number of stress release grooves is 24-48, and the width is 2-5 mm.

[0034] S5) nitrile butyl phenolic adhesive is uniformly brushed on each bonding surface of the inner and outer surfaces of the skirt and the rubber buffer layer, and the rubber buffer layer is bonded to the inner and outer surfaces of the skirt, then vacuumization is carried out at 60-70 DEG C for 2-6 h, and the vacuum degree is -90 to -110 KPa. The rubber buffer layer is bonded to the inner and outer surfaces of the skirt in advance, which effectively avoids the sliding phenomenon of the rubber buffer layer caused by friction during the upper skirt process, and effectively ensures the bonding strength of the skirt and the rubber buffer layer.

[0035] S6) nitrile butyl phenolic adhesive is uniformly brushed on the surface of the buffer layer of the inner surface of the skirt, the skirt is installed to the skirt bonding area of the uncured shell, and the interval between the front and rear skirts and the quadrant deviation are ensured.

[0036] S7) nitrile butyl phenolic adhesive is uniformly brushed on the surface of the buffer layer of the outer surface of the skirt, then 5-7 layers of ring winding are wound back and forth from the front equator line position to the front skirt tip, the continuous yarn is wound to the surface of the uncured shell after the binding of the skirt is finished, and the skirt tip triangular area is leveled, then the rear skirt is also ring wound, and finally the outer ring winding of the skirt is completed; the starting point of the binding of the skirt is wound back and forth from the equator line to the skirt tip, and the tension of the single yarn is 50-70 N.

[0037] S8) a layer of glue absorbing cloth is laid on the surface of the uncured shell after the ring winding is finished, then glass fiber yarn is used for ring winding on the surface of the uncured shell, and the uncured shell is hoisted into the curing furnace for rotary curing after the ring winding is finished.

[0038] The bonding forming method of the application improves the bonding quality of the upper skirt, and has strong process reliability, and is suitable for wet upper skirt fiber winding shell.

Claims

1. A fiber-wound shell skirt bonding molding method, characterized in that: The bonding molding method comprises the following steps: S1) selecting a winding core mold according to the aspect ratio of the fiber-wound shell, and machining the winding core mold according to the inner surface of the insulation layer of the fiber-wound shell after the winding core mold is formed; S2) pasting the inner insulation layer onto the winding core mold, and grinding the skirt bonding area on the surface of the inner insulation layer with an automatic grinder; S3) performing skirt winding on the surface of the inner thermal insulation layer in a winding manner alternating between spiral winding and hoop winding to obtain an uncured shell; S4) machining a stress relief groove on the skirt at a bonding area with the uncured shell; S5) Use nitrile phenolic adhesive to evenly apply it to the inner and outer surfaces of the skirt and the bonding surfaces of the rubber buffer layer, and bond the rubber buffer layer to the inner and outer surfaces of the skirt, and then vacuum cure; S6) evenly applying nitrile phenolic adhesive to the buffer layer on the inner surface of the skirt, and installing the skirt to the skirt bonding area of ​​the uncured shell; S7) Evenly apply nitrile phenolic adhesive on the buffer layer on the outer surface of the skirt, then tie the skirt and wrap it in a hoop; S8) laying a layer of adhesive tape on the surface of the uncured shell after the hoop winding is completed, and then hoisting the uncured shell surface with glass fiber yarn. After the hoop winding is completed, the shell is hoisted into a curing furnace for rotation curing; In step S3), the shell interference is controlled during the hoop winding before the last spiral winding, and then the last spiral winding is performed; the specific method of controlling the interference is: First, confirm the theoretical required dimensions: set the skirt bonding starting point to (0, (D1-d-2h-0.5) / 2) and the skirt tip to (L, (D2-d-2h+2) / 2), where D1 is the inner diameter of the skirt bonding starting point, d is the increment of the diameter of a spirally wound uncured shell, D2 is the inner diameter of the skirt tip, h is the thickness of the rubber buffer layer, and L is the axial length from the skirt bonding starting point to the skirt tip; then substitute the skirt bonding starting point and the skirt tip into the equation Y=kX+b to calculate the values ​​of k and b, and then take a diameter value Y every 20~40mm from the skirt bonding starting point. n As the measurement point, that is, X n =20~40n, n=1, 2, 3..., until LX n ≤20mm, each diameter Y n Tolerance is ±0.3mm; Measure the outer diameter of the uncured shell before the last spiral winding for the first time, and confirm the required winding thickness a for each measuring point by comparing the actual measured value with the theoretical required size. Then divide the winding thickness a by the single-layer circumferential winding thickness increment b, and round down to get the number of circumferential layers c1 required for each measuring point. Start with the position of the maximum number of circumferential layers 10~20mm on the side of the barrel section as the starting point, and perform circumferential winding in the direction of the skirt bonding starting point until it passes the position of the minimum number of circumferential layers on this side by 10~20mm. Then run the reverse circumferential winding until it passes the position of the minimum number of circumferential layers on the other side by 10~20mm. If the maximum number of circumferential layers is at the skirt tip, then pass the skirt. The tip is 10~20mm, and then starting from this point, continue to perform patching according to the above requirements, so that the actual number of circumferential layers of patching at each position for the first time meets c1 or c1-1; after the first patching is completed, measure the outer diameter of the uncured shell for the second time, and adopt the above-mentioned method for calculating the number of circumferential layers of patching to obtain the number of circumferential layers c2 for the second patching, and perform the above-mentioned patching operation so that the actual number of circumferential layers of patching for the second time meets c2 or c2-1; finally, measure the outer diameter of the uncured shell for the third time, and adopt the above-mentioned method for calculating the number of circumferential layers of patching to obtain the number of circumferential layers c3 for the third patching, and only need to perform circumferential winding in situ for the corresponding number of circumferential layers c3 at the patching position.

2. The fiber-wound shell skirt bonding molding method according to claim 1, characterized in that: The winding core mold is a gypsum core mold or a sand core mold.

3. The fiber-wound shell skirt bonding molding method according to claim 1, characterized in that: In the step S4), the length of the stress relief groove extends from the skirt bonding starting point to the skirt tip.

4. The fiber-wound shell skirt bonding molding method according to claim 1, characterized in that: In the step S4), the number of the stress relief grooves is 24 to 48, and the width is 2 to 5 mm.

5. The fiber-wound shell skirt bonding molding method according to claim 1, characterized in that: In the step S5), curing is carried out at 60-70° C. for 2-6 hours, and the vacuum degree is -90-110 KPa.

6. The fiber-wound shell skirt bonding molding method according to claim 1, characterized in that: The specific process of step S7) tying the skirt and circumferentially winding is as follows: starting from the front equator position, circumferentially winding 5 to 7 layers of skirt tying layers back and forth towards the skirt tip; after the skirt tying is completed, the yarn is continuously wound to the surface of the uncured shell and the triangle area of ​​the skirt tip is leveled, and then the rear skirt is circumferentially wound in the same manner, and finally the circumferential winding of the skirt outer surface is completed.

7. The fiber-wound shell skirt bonding molding method according to claim 1, characterized in that: In the step S7), the skirt binding starting point is wound back and forth from the equator to the skirt tip, and the tension of the single yarn is 50-70N.