CN115488581A - Method for accurately manufacturing double-curvature stringer - Google Patents

Abstract

The invention discloses a method for accurately manufacturing a double-curvature stringer. Sinking the double-curvature stringer subjected to profile forming; the processing method comprises the following steps: a. marking a first sunken processing position of the stringer by taking the head end of the stringer as a positioning reference, stamping the first sunken stringer according to the marking, and detecting the sunken stringer subjected to stamping by using a die mould surface (1) after the stamping is finished; b. repeating the step a to complete the punching processing of the remaining stringer sink; c. after all the stringer sag processing is completed, the length allowance at the other end is cut off by taking the head end of the stringer as a reference. The invention has the characteristics of high forming precision, stable quality, high production efficiency, strong universality and easy operation.

Description

A Precise Manufacturing Method for Double Curvature Long Strings

technical field

The invention belongs to the technical field of plastic forming, and in particular relates to a method for precisely manufacturing double-curvature stringers.

Background technique

The existing manufacturing and inspection of double curvature long truss parts adopts the method of inspecting the bracket template (see Figure 1), and the shape and direction of the long truss parts are controlled by checking the line contact between the bracket template and the long truss parts at the frame position. The determination of the sag position is controlled by marking the size of the scribing diagram based on the scribing of the inspection bracket template. It is impossible to accurately control the entire shape and direction of the truss parts, but only the shape and direction of the truss parts at the frame position. During the assembly process It often occurs that the shape of the long truss parts on the assembly frame and the skin fit gap and the position of the sag is relatively large (see Figure 2), which cannot meet the assembly needs and cause the parts to be repaired, thereby affecting the assembly cycle and assembly quality. In order to solve the problem of large aircraft Due to the poor manufacturing accuracy and high repair rate of double curvature long truss parts, it is necessary to improve the double curvature long truss.

Contents of the invention

The object of the present invention is to provide a precise manufacturing method for double curvature stringers. The invention has the characteristics of high forming precision, stable quality, high production efficiency, strong versatility and easy operation.

The technical solution of the present invention is: a method for accurately manufacturing double curvature stringers, which performs sinking processing on the double curvature stringers that have been shaped; the processing method is as follows:

a. With the head end of the long stringer as the positioning reference, mark the first sinking processing position of the long stringer, and stamp the first sinking of the long stringer according to the marking line. After completion, use the mold tire to face the punched long stringer Truss subsidence detection;

b. Repeat step a to complete the stamping process for the remaining stringers sinking;

c. After finishing all the sagging processing of the stringer, cut off the length allowance at the other end based on the head end of the stringer.

In step a of the above-mentioned precise manufacturing method for double-curvature long stringers, the positioning datum of the head end of the long stringers is determined by a positioning block located on one side of the molded tire profile.

In step a of the above-mentioned precise manufacturing method for double-curved stringers, the detection of sinking of stringers is as follows: placing the processed double-curved stringer with sinking of stringers on the surface of the molded tire and comparing it with the detection line for sinking.

In the step c of the above-mentioned precise manufacturing method of the double-curvature stringer, the length margin at the other end of the double-curvature stringer is cut off, and the cut-off is performed according to the cut-off line after marking with the marking-line block provided on the surface of the molded tire. .

In the above-mentioned precise manufacturing method of the double-curvature stringer, the scribing block has a stringer passing groove reserved at the bottom, and the outline of the outer end of the stringer passing through the groove forms an end allowance removal line.

In the above-mentioned precise manufacturing method of the double-curvature stringer, the marking process of the scribing block is as follows: After one end of the double-curvature stringer is positioned by the positioning block, the other end passes through the bottom of the marking block and is reserved The girders pass through the slots, and the double-curved girders are attached together. At this time, the line is drawn along the end allowance removal line formed by the girders through the outline of the outer end of the slots, and then the end of the double-curved girders is determined. Miter angle and notch location.

In the above-mentioned precise manufacturing method of the double-curvature stringer, the said scoring block is positioned on the surface of the molded tire by pins.

In step a of the above-mentioned precise manufacturing method for double-curvature long stringers, when marking the sinking processing position of the long stringers, the position of the marking line in the length direction is compensated according to the following table,

Sinking Depth(mm) Compensation value(mm) less than 1.0 0.1 1.0-1.5 0.2 1.5-2.5 0.25 greater than 2.5 0.3

.

The advantages of the present invention are: compared with the prior art, the present invention can ensure the precise manufacture of aviation long stringer parts; the aviation long stringer reduces the influence of human factors on product quality by the detachable end positioning block of the aviation stringer, and improves the product quality. It ensures the stability of product quality; this aspect is applicable to the manufacture of all aviation hyperbolic truss parts, and has strong versatility.

The present invention analyzes the problems existing in the process of manufacturing, inspecting and assembling the double-curvature long truss parts according to the inspection bracket template, the manufacturing standard and assembly standard of the long truss parts are not uniform, the end of the long truss is marked and the machining allowance is cut Phenomena such as inaccurate control, large deviation of the sinking forming position, and large gap between tires and other phenomena are caused by the large errors in the length, curvature, and lower limit position of the double-curvature long truss parts during the assembly process. Common problems such as low quality lead to high parts rework rate and unstable quality. In order to solve this problem, the present invention makes the following improvements to the manufacturing process of double-curved truss parts:

(1) Unify parts manufacturing standards and assembly standards

When manufacturing parts, the end of the girder and the sagging forming datum are unified and consistent with the assembly positioning datum, so as to realize the goal of changing the sag position positioning of the long truss to the end positioning, and reduce the inconsistency between part manufacturing and assembly positioning datum. error accumulation;

(2) Control the cutting of the scribing line and machining allowance at the end of the stringer

By controlling the size of the end of the girder (assembly positioning reference end), adding positioning blocks (see Figure 3 and Figure 4) on the inspection mold (membrane surface) of the girder to ensure the accuracy and consistency of the assembly positioning end At the same time, a marking block is designed (see Figure 3, 5, 6), which realizes the accurate control of cutting and drawing lines at the end of the stringer.

(3) Control the sinking forming position

The sag is formed by drawing lines separately to reduce the positional deviation caused by material shrinkage during the sag stamping forming. At the same time, the process method is improved to clarify that the sag is formed after the shape of the long truss is completed. The sag should be drawn with the reference end of the assembly as the reference when forming the sag. Line forming to ensure that the relative position of the sag is consistent with the assembly requirements; when there are 2 or more sags in the stringer, draw lines and form them separately (that is, after the first sag is formed, draw a line to form the next sag) to ensure that the sags are between relative positional accuracy.

Refer to Fig. 7-Fig. 10 for specific technical effects. It can be seen from Fig. 7 that before the implementation: the manufacturing shape deviation of parts has reached 15mm. After implementation: the part manufacturing shape deviation can be controlled within 0.4mm, and the effect is remarkable; as can be seen from Figures 8 and 9, before implementation: the maximum tire bonding gap reaches 5mm, and the fit between the long truss parts and the skin is low. After implementation: the gap between the tires is less than 0.4mm, and the fit between the stringer parts and the skin is significantly improved. It can be seen from Fig. 10 that the parts manufactured by the present invention have very little deviation in the length direction.

To sum up, the present invention unifies parts manufacturing and assembling standards, accurately controls the cutting of the line drawn at the end of the long truss and the cutting of the machining allowance, controls the degree of sinking forming position and other improvement measures, so that the shape and sinking position of the double curvature long stringer parts The problems of large deviation and low fit with the skin have been significantly improved, and the precise manufacturing of double-curvature long truss parts has been realized, the workload of on-site milling and repair has been reduced, and the repair rate of double-curvature long truss parts has been reduced by 90% % or more, effectively improving the assembly quality of parts and reducing production costs.

Description of drawings

Figure 1 is a schematic diagram of the manufacturing and inspection methods of traditional double curvature truss parts;

Figure 2 is a schematic diagram of common problems in the manufacture of traditional double curvature truss parts;

Fig. 3 is a structural representation of the present invention;

Fig. 4 is the schematic diagram of enlarged structure at I place of Fig. 3;

Fig. 5 is a schematic diagram of the enlarged structure at II of Fig. 3;

Fig. 6 is a schematic diagram of the structure of the marking block;

Fig. 7 is the comparison of the shape deviation of the stringer parts on the tooling after implementing the present invention and the traditional method;

Fig. 8 is the comparison of the sticking gap of the stringer parts on the mold tire after implementing the present invention and the traditional method;

Fig. 9 is the comparison of the bonding degree between the stringer part and the skin after implementing the present invention and the traditional method;

Fig. 10 is a comparison of the length deviation of stringer parts on molded tires after implementing the present invention and the traditional method.

Among them: 1-model tire surface, 2-positioning block, 3-marking block, 4-long stringer passing through the groove, 5-end allowance removal line, 6-pin, 7-double curvature long stringer, 8-Sag detection line.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but not as a basis for limiting the present invention.

Example 1. A precise manufacturing method of a double curvature stringer, referring to Fig. 3-6, performs sinking processing on the shape shaped double curvature stringer 7; the processing method is as follows:

a. With the head end of the long stringer as the positioning reference, mark the first sinking processing position of the long stringer, and stamp the first sinking of the stringer according to the marking line. After completion, use the mold tire surface 1 to pair the stamped The sag of the long truss is detected; when the parts are manufactured, the ends of the long truss and the sag forming datum are unified and consistent with the assembly positioning datum, so as to realize the goal of changing the sag position positioning of the long truss to the end positioning, and reduce parts manufacturing and assembly. Accumulation of errors caused by inconsistencies in positioning benchmarks;

b. Repeat step a to complete the stamping process for the remaining sags; through steps a and b, the sags are formed by drawing lines respectively to reduce the position deviation caused by material shrinkage during stamping and forming of the sags, and at the same time improve the process method to clarify the length The shape of the truss parts is formed after the sag is formed. When the sag is formed, the assembly reference end should be used as the reference to draw lines to ensure that the relative position of the sag is consistent with the assembly requirements; Forming (that is: after forming the first sag, draw a line to form the next sag), to ensure the accuracy of the relative position between the sags.

c. After finishing all the sagging processing of the stringer, cut off the length allowance at the other end based on the head end of the stringer. By controlling the size of the assembly and positioning datum end of the girder end, a positioning block (see Figure 3) is added to the inspection mold (membrane surface) of the girder to ensure the accuracy and consistency of the assembly positioning end; at the same time, the A scribing block 3 realizes accurate control of cutting and scribing lines at the end of the stringer.

In step a, the positioning datum of the long stringer head end is determined by the positioning block 2 located on one side of the molded tire profile 1 .

In step a, the detection of stringer sinking is as follows: place the double-curvature stringer with processed stringer sinking on the molded tire surface 1 and compare it with the sinking detection line 8 on it.

In step c, the length margin at the other end of the double-curvature stringer is cut off, and the marking line block 3 provided on the molded tire profile 1 is used to mark the line and then cut off according to the line.

The aforesaid scribing block 3 is reserved at the bottom with a long stringer passing through the groove 4, and the outer end outline of the long stringer passing through the groove 4 forms an end allowance removal line 5.

The scribing process of the aforementioned scribing block 3 is as follows: After one end of the double-curvature stringer is positioned with the positioning block 2, the other end passes through the long stringer reserved at the bottom of the scribing block 3 and passes through the slot 4, and the double Curved girders are fitted together. At this time, a line is drawn along the end margin removal line 5 formed by the girder passing through the outline of the outer end of the groove 4, so as to determine the bevel angle and notch position of the end of the double curvature girder.

The aforesaid scoring block 3 is positioned on the molded tire profile 1 by pins 6 .

In step a, when marking the sagging processing position of the girder, the position of the marking line in the length direction is compensated according to the following table,

Sinking Depth(mm) Compensation value(mm) less than 1.0 0.1 1.0-1.5 0.2 1.5-2.5 0.25 greater than 2.5 0.3

.

Claims (8)

1. A double-curvature stringer precise manufacturing method is characterized in that, the double-curvature stringer that has carried out shape forming is carried out sinking processing; Described processing method is as follows: a. With the head end of the long stringer as the positioning reference, mark the first sinking processing position of the long stringer, and stamp the first sinking of the long stringer according to the marking line, and use the molded tire surface (1) to stamp the punched The sag of the processed stringer is inspected; b. Repeat step a to complete the stamping process for the remaining stringers sinking; c. After finishing all the sagging processing of the stringer, cut off the length allowance at the other end based on the head end of the stringer. 2. The double-curvature long stringer precision manufacturing method according to claim 1, characterized in that, in step a, the positioning reference of the long stringer head end is determined by the positioning block (2) on one side of the molded tire profile (1) )Finish. 3. The method for accurately manufacturing double-curved stringers according to claim 1, characterized in that in step a, the detection of sinking stringers is as follows: placing the double-curvature stringers processed with sinking stringers on the mold tire The profile (1) is compared with the sag detection line on it. 4. The double-curvature stringer precision manufacturing method according to claim 1, characterized in that, in step c, the length margin at the other end of the double-curvature stringer is cut off, and the molded tire surface (1) is used The scribed line is cut off according to the scribed line after being scribed by the block (3). 5. The double-curvature stringer precision manufacturing method according to claim 4, characterized in that, said marking block (3) has a stringer passage groove (4) reserved at the bottom, and the stringer passage groove (4) 4) The outline of the outer end forms the end allowance removal line (5). 6. The double-curvature stringer precision manufacturing method according to claim 5, characterized in that, the marking process of the scribing block (3) is as follows: one end of the double-curvature stringer is positioned using a positioning block ( 2) After positioning, the other end passes through the long stringer passing groove (4) reserved at the bottom of the marking block (3), and makes the double curvature long stringer fit together. At this time, pass through the groove (4) outside the long stringer The end margin removal line (5) formed by the end contour line is marked, and then the bevel angle and the notch position of the end of the double-curvature stringer are determined. 7. The precise manufacturing method of the double-curvature long stringer according to claim 5, characterized in that, the scribing block (3) is positioned on the molded tire profile (1) through pins (6). 8. The double-curvature stringer precision manufacturing method according to claim 1, characterized in that, in step a, when marking the sinking processing position of the stringer, the position of the marking line in the length direction is determined according to the following table compensate, Sinking Depth(mm) Compensation value(mm) less than 1.0 0.1 1.0-1.5 0.2 1.5-2.5 0.25 greater than 2.5 0.3 .

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