A centering jig auxiliary tool for a large-length-diameter thin-wall shell

Abstract

The application discloses a center frame auxiliary tool for a large-length-diameter thin-wall shell, which comprises, from inside to outside, aluminum semi-circular rings, steel semi-circular rings and aluminum outer bushings; the two aluminum semi-circular rings embrace the outer circle of the shell to form a first whole circle; the two steel semi-circular rings embrace the outer circle of the first whole circle to form a second whole circle; and the aluminum outer bushings embrace the outer circle of the second whole circle. The center frame auxiliary tool can support the middle position of the large-length-diameter thin-wall shell, solves the vibration problem of the shell during turning of the middle part of the shell, and thus realizes turning of the middle part of the thin-wall shell; meanwhile, the shell is uniformly stressed during use, and the center frame auxiliary tool can minimize the secondary deformation of the shell caused by the center frame auxiliary tool itself.

Description

Technical Field

[0001] This invention relates to the field of machining, specifically to an auxiliary tooling for mounting a center frame on a thin-walled shell with a large length-to-diameter ratio. Background Technology

[0002] A thin-walled shell with a high length-to-diameter ratio is a crucial component of a solid rocket motor. This shell has a length-to-diameter ratio of 12:1, with large outer diameters at both ends and a small outer diameter in the middle. A turning structure is designed in the middle of the shell, and the coaxiality of this turning structure must be controlled within φ0.1. Conventional turning of the shell uses a "one-clamp-one-support" clamping method (one end clamped by a four-jaw chuck, the other end secured by a tailstock). However, the lack of rigidity in the middle section leads to turning vibrations, failing to meet the design and machining requirements of the middle structure. For common high length-to-diameter ratio parts such as crankshafts and drive shafts, the "one-clamp-one-support" clamping method is typically supplemented with auxiliary supports such as a center rest and a follower rest to enhance the stability of the workpiece during machining and prevent turning vibrations and deformation. The center rest and follower rest are rigid supports, requiring the supported area of ​​the workpiece to be a finished surface with good rigidity. The middle part of the shell has poor rigidity after spinning and heat treatment, and there is irregular deformation. There is no machining allowance in the support position, and it is impossible to form a finished surface. This means that the center rest and follow rest cannot be used directly for support during the shell turning process.

[0003] Therefore, a tooling is needed that can assist in the construction of a center rest to provide additional support when turning the middle structure of the housing. This tooling needs to be able to adapt to the irregular deformation of the outer circle of the housing itself, have sufficient rigidity to use the center rest to provide auxiliary support, and not cause further deformation of the housing. Summary of the Invention

[0004] The technical problem solved by the present invention is to overcome the shortcomings of the prior art and provide an auxiliary tooling for erecting a center frame for a thin-walled shell with a large length-to-diameter ratio, so as to meet the auxiliary support requirements for erecting a center frame when turning the middle structure of the shell.

[0005] A central frame auxiliary tooling for a thin-walled shell with a large length-to-diameter ratio, comprising, from the inside out, an aluminum semi-circular ring, a steel semi-circular ring, and an aluminum outer bushing;

[0006] The aluminum semi-circular rings are two in number, encircling the outer circumference of the shell to form the first complete circle;

[0007] The steel semicircular rings are two in number, encircling the outer circle of the first complete circle to form the second complete circle;

[0008] The aluminum outer bushing surrounds the outer circle of the second complete circle.

[0009] A central frame auxiliary tooling for a thin-walled shell with a large length-to-diameter ratio is provided, wherein two symmetrical aluminum bosses are provided at one end of the outer circular surface of the aluminum semi-circular ring, and the aluminum bosses are provided with radial threaded holes; except for the aluminum bosses, the rest of the aluminum semi-circular ring is a thin-walled semi-circular ring.

[0010] A central frame auxiliary tooling for a thin-walled shell with a large length-to-diameter ratio, wherein steel boss structures are provided on the upper and lower outer sides of both ends of the steel semi-circular ring, and a tightening threaded hole is provided in the middle of the steel boss for connecting the steel semi-circular ring.

[0011] The tightening threaded hole includes a through hole, a pin hole, and a radially stepped through hole;

[0012] The through hole is used to connect the two steel semi-circular rings;

[0013] The pin hole includes an axial positioning pin hole and a radial positioning pin hole, which are used to position the two steel semi-circular rings. To ensure the docking accuracy of the two steel semi-circular rings after disassembly and reassembly, the axial pin hole and the radial pin hole are processed after the two steel semi-circular rings are assembled into a complete circle.

[0014] The radial stepped through hole is used to connect the two steel semi-circular rings and the two aluminum semi-circular rings.

[0015] The steel semi-circular ring is a thick-walled semi-circular ring; the steel semi-circular ring is provided with double-row radially staggered and evenly distributed threaded holes for installing tightening bolts.

[0016] A central frame auxiliary tooling for a thin-walled shell with a large length-to-diameter ratio, wherein the aluminum outer bushing is a thick-walled aluminum ring, and the aluminum outer bushing is a consumable with a radial thickness greater than 20 mm during use.

[0017] A central support tooling for a thin-walled shell with a large aspect ratio is provided, wherein the rotation axis of the first full circle coincides with the rotation axis of the shell; the rotation axis of the second full circle coincides with the rotation axis of the first full circle; and the rotation axis of the aluminum outer bushing coincides with the rotation axis of the second full circle.

[0018] The assembly sequence from the inside out is as follows: the housing, the first complete circle, the second complete circle, and the aluminum outer bushing.

[0019] A central frame auxiliary tooling for a thin-walled shell with a large aspect ratio is provided, wherein the inner circle of the first complete circle is in direct contact with the shell with a clearance fit; the inner circle of the second complete circle is in clearance fit with the outer circle of the first complete circle; and the inner circle of the aluminum outer bushing is in transition fit with the outer circle of the second complete circle.

[0020] A central frame auxiliary tooling for a thin-walled shell with a large length-to-diameter ratio is provided, wherein the steel semi-circular ring and the aluminum semi-circular ring are connected by screws; the two steel semi-circular rings are positioned by radial positioning pins and axial positioning pins, and are fastened together by fastening bolts and fastening nuts.

[0021] A central frame auxiliary tooling for a thin-walled shell with a large length-to-diameter ratio, wherein the steel semi-circular ring is tightened to the aluminum semi-circular ring by the tightening bolt through the double-row radially staggered and evenly distributed threaded holes reserved on the thick-walled semi-circular ring in the middle of the steel semi-circular ring;

[0022] The aluminum semi-circular ring can locally deform to adapt to the irregular deformation of the outer circle of the housing itself, and prevent the housing from being damaged by the tightening bolt.

[0023] A central frame auxiliary tooling for a thin-walled shell with a large length-to-diameter ratio is provided, wherein the second full-circle rotation axis is initially aligned with the rotation axis of the shell by adjusting the tightening bolts installed on the steel semi-circular ring.

[0024] A central support fixture for a thin-walled shell with a large aspect ratio is provided, wherein after each installation, the outer diameter of the aluminum outer bushing needs to be machined to ensure that its axis of rotation is coaxial with the axis of rotation of the shell, thereby achieving precise alignment between the axis of rotation of the central support fixture for the thin-walled shell with the axis of rotation of the thin-walled shell.

[0025] The advantages of this invention compared to the prior art are:

[0026] (1) The present invention can adapt to the deformation of the outer circle of the shell itself, and the deformation of the shell is small when the large length-diameter ratio thin-walled shell with central frame auxiliary tooling is used. The shell is subjected to uniform force during use, which can minimize the secondary deformation of the shell caused by the large length-diameter ratio thin-walled shell with central frame auxiliary tooling itself.

[0027] (2) The present invention has high adjustment accuracy and strong adaptability. The auxiliary tooling for the center frame of the thin-walled shell with a large length-to-diameter ratio can be applied to shells in different deformation states. By adjusting the tightening bolts on the steel semi-circular ring, the rotation axis of the auxiliary tooling for the center frame of the thin-walled shell with a large length-to-diameter ratio can be initially corrected. By turning the outer circle of the aluminum outer bushing, the rotation axis of the auxiliary tooling for the center frame of the thin-walled shell with a large length-to-diameter ratio can be precisely corrected, so that the rotation axis of the auxiliary tooling for the center frame of the thin-walled shell with a large length-to-diameter ratio is coaxial with the rotation axis of the shell.

[0028] (3) The large length-to-diameter ratio thin-walled shell with central frame auxiliary tooling in this invention has strong rigidity. It is installed on the outer circle of the shell, which enhances the rigidity of the shell and reduces turning vibration.

[0029] (4) The present invention has low cost. For shells in different deformation states, the present invention only needs to consume the outermost aluminum bushing; the aluminum semi-circular ring and the steel semi-circular ring can be used continuously without replacement, which can effectively reduce processing costs. Attached Figure Description

[0030] To more clearly illustrate the technical solutions disclosed in this invention, the accompanying drawings used in some embodiments of this invention will be briefly described below. Obviously, the drawings described below are merely drawings of some embodiments of this invention, and those skilled in the art can obtain other drawings based on these drawings. Furthermore, the drawings described below can be considered schematic diagrams and are not intended to limit the actual dimensions of the products or the actual flow of the methods involved in the embodiments of this invention.

[0031] Figure 1 The diagram shown illustrates a usage scenario of the present invention.

[0032] Figure 2 The image shown is an isometric view of the assembly of the present invention.

[0033] Figure 3 The diagram shown is a partial cross-sectional assembly diagram of the present invention.

[0034] Figure 4a The figures shown are a front view and a cross-sectional view of the aluminum semicircular ring of the present invention.

[0035] Figure 4b The image shown is an isometric view of the aluminum semicircular ring of this invention.

[0036] Figure 5a The image shown is a front view of the steel semicircular ring of the present invention.

[0037] Figure 5b The image shown is an isometric view of the steel semicircular ring of this invention.

[0038] Figure 5c The figures shown are BB and CC cross-sectional views of the steel semi-circular ring of the present invention.

[0039] Figure 5d The image shown is a DD cross-sectional view of the steel semicircular ring of the present invention.

[0040] Figure 5e The figures shown are EE and FF cross-sectional views of the steel semi-circular ring of the present invention.

[0041] Figure 6 The images shown are the front view and sectional view of the aluminum outer bushing of the present invention.

[0042] In the diagram: 1 is an aluminum outer bushing, 2 is an axial positioning pin, 3 is a fastening nut, 4 is a steel semi-circular ring, 5 is a tightening bolt, 6 is a radial positioning pin, 7 is a fastening bolt, 8 is a connecting screw, 9 is an aluminum semi-circular ring, 10 is the machine tool tailstock, 11 is the housing, 12 is the auxiliary tooling for the large length-to-diameter ratio thin-walled housing with a center rest, 13 is the center rest, 14 is the machine tool bed, and 15 is the machine tool chuck. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0044] A central frame auxiliary tooling for a thin-walled shell with a large length-to-diameter ratio includes, from the inside out, an aluminum semi-circular ring 9, a steel semi-circular ring 4, and an aluminum outer bushing 1.

[0045] The aluminum semicircular rings 9 are two in number, encircling the outer circle of the shell 11 to form the first complete circle;

[0046] The steel semicircular ring 4 consists of two rings, which encircle the outer circle of the first complete circle to form the second complete circle;

[0047] The aluminum outer bushing 1 surrounds the outer circle of the second complete circle.

[0048] Two symmetrical aluminum bosses are provided on one end of the outer surface of the aluminum semi-circular ring 9. The aluminum bosses are provided with radial threaded holes for connecting the steel semi-circular ring 4. Except for the aluminum bosses, the rest of the aluminum semi-circular ring 9 is a thin-walled semi-circular ring.

[0049] The upper and lower outer sides of the two ends of the steel semi-circular ring 4 are provided with steel boss structures, and the middle of the steel boss is provided with a tightening threaded hole.

[0050] The tightening threaded hole includes a through hole, a pin hole, and a radially stepped through hole;

[0051] The through hole is used to connect the two steel semi-circular rings;

[0052] The pin hole includes an axial positioning pin hole and a radial positioning pin hole, which are used to position the two steel semi-circular rings 4. In order to ensure the docking accuracy of the two steel semi-circular rings 4 after disassembly and reassembly, the axial pin hole and the radial pin hole are processed after the two steel semi-circular rings 4 are assembled into a complete circle.

[0053] The radial stepped through hole is used to connect the two steel semi-circular rings 4 and the two aluminum semi-circular rings 9.

[0054] The steel semi-circular ring 4 is a thick-walled semi-circular ring; the steel semi-circular ring 4 is provided with double-row radially staggered and evenly distributed threaded holes for installing the tightening bolt 5.

[0055] The aluminum outer bushing 1 is a thick-walled aluminum ring, which is a consumable and has a radial thickness greater than 20mm when in use.

[0056] The rotation axis of the first complete circle coincides with the rotation axis of the housing 11; the rotation axis of the second complete circle coincides with the rotation axis of the first complete circle; the rotation axis of the aluminum outer bushing 1 coincides with the rotation axis of the second complete circle.

[0057] The assembly sequence from the inside out is as follows: the housing 11, the first complete circle, the second complete circle, and the aluminum outer bushing 1.

[0058] The inner circle of the first complete circle is in direct contact with the housing 11 with a clearance fit; the inner circle of the second complete circle is in clearance fit with the outer circle of the first complete circle; and the inner circle of the aluminum outer bushing 1 is in transition fit with the outer circle of the second complete circle.

[0059] The steel semi-circular ring 4 and the aluminum semi-circular ring 9 are connected by screws 8; the two steel semi-circular rings 4 are positioned by radial positioning pins 6 and axial positioning pins 2, and are fastened together by fastening bolts 7 and fastening nuts 3.

[0060] The steel semicircular ring 4 uses the tightening bolt 5 to tighten the aluminum semicircular ring 9 through the double-row radially staggered and evenly distributed threaded holes reserved on the thick-walled semicircular ring in the middle of the steel semicircular ring 4.

[0061] The aluminum semi-circular ring 9 can locally deform to adapt to the irregular deformation of the outer circle of the housing 11 itself, and prevent the housing 11 from being damaged by the tightening bolt 5.

[0062] By adjusting the tightening bolts 5 installed on the steel semi-circular ring 4, the second full-circle rotation axis is initially aligned with the rotation axis of the housing 11.

[0063] After each installation, the outer circle of the aluminum outer bushing 1 needs to be machined to ensure that its rotation axis is coaxial with the rotation axis of the housing 11, so as to achieve precise alignment between the rotation axis of the auxiliary tooling 12 for the large length-to-diameter ratio thin-walled housing and the rotation axis of the thin-walled housing 11.

[0064] This invention is preferably used as an auxiliary support during the machining of the middle structure of a certain type of thin-walled shell with a large length-to-diameter ratio.

[0065] This invention needs to be used on a lathe / CNC lathe equipped with a tailstock and a center rest. The specifications of the lathe / CNC lathe should meet the following requirements: the maximum turning diameter of the slide plate is greater than or equal to 450 mm, the effective travel of the Z-axis is greater than or equal to 5000 mm, the maximum clamping diameter of the center rest is greater than or equal to 560 mm, and the minimum clamping diameter is less than or equal to 450 mm.

[0066] The thin-walled shell with a large length-to-diameter ratio, after heat treatment for reinforcement, exhibits varying degrees of deformation and is a thin-walled cylindrical welded component with a turning structure in the middle. Excluding the central machining structure and the joints at both ends, the shell has a diameter of 370 mm, a wall thickness of only 2.1 mm, and a length-to-diameter ratio of 12:1.

[0067] Using this invention for the turning of a certain type of thin-walled shell with a large length-to-diameter ratio, auxiliary support can be provided for the middle part of the shell during the turning process, solving the vibration problem in the turning process of the middle structure of the shell and ensuring the scientific research and production tasks of the shell.

[0068] The application scenarios of the large aspect ratio thin-walled shell with central support auxiliary tooling in this invention are as follows: Figure 1 As shown, one end of the housing 11 is clamped by a machine tool chuck 15, and the other end is secured by a machine tool tailstock 10. A center rest auxiliary fixture 12 for the thin-walled housing with a large length-to-diameter ratio is installed on the housing 11 near the middle of the structure to be machined 11-1. The center rest 13 is mounted on the machine tool bed 14 and adjusted to a suitable position. It is then supported by a three-point support system on the center rest auxiliary fixture 12 for auxiliary support.

[0069] Preferably, the through holes at both ends of the two steel semicircular rings 4 are aligned, and then fastened together using fastening bolts 7 and fastening nuts 3 to form a second complete circle. Figure 5a The radial and axial positioning pin holes shown are matched with positioning pin holes to ensure the consistency of the two steel semi-circular rings 4 after disassembly and reassembly.

[0070] Preferred, such as Figure 2 , Figure 3 As shown, the radial threaded hole at one end of the aluminum semi-circular ring 9 is aligned with the radial stepped through hole at either end of the steel semi-circular ring 4, and they are connected using connecting screws 8. The two aluminum semi-circular rings 9 encircle the housing 11 to form a first complete circle, and the two steel semi-circular rings 4 encircle the outer circle of the first complete circle to form a second complete circle.

[0071] Preferred, such as Figure 2 , Figure 3 As shown, the radial positioning pin 6 is installed in the radial positioning pin hole formed by the two steel semicircular rings 4, and the axial positioning pin 2 is installed in the axial positioning pin hole formed by the two steel semicircular rings 4.

[0072] Preferred, such as Figure 2 , Figure 3 As shown, the tightening bolt 5 is installed in a double row of radially staggered threaded holes in the middle of the steel semi-circular ring 4, and the head of the tightening bolt 5 contacts the outer circle of the aluminum semi-circular ring 9. By adjusting the tightening bolt 5, the following can be achieved:

[0073] 1. The thin-walled portion of the aluminum semi-circular ring 9 deforms along with the shell 11, and the large length-diameter ratio thin-walled shell with the central frame auxiliary tooling 12 fits more tightly with the shell 11.

[0074] 2. Initially correct the outer circle of the second complete circle to maximize the coaxiality between the rotation axis of the steel semi-circular ring 4 and the rotation axis of the housing 11;

[0075] 3 The steel semi-circular ring 4 and the aluminum semi-circular ring 9 are securely installed in the housing 11.

[0076] Preferred, such as Figure 2 , Figure 3 As shown, the aluminum outer bushing 1 is installed on the steel semi-circular ring 4, and the inner circle of the aluminum outer bushing 1 is clearance-fitted with the outer circle of the second full circle. After the aluminum outer bushing 1 is installed, the outer circle of the aluminum outer bushing 1 is machined until it is smooth. When machining the outer circle of the aluminum outer bushing 1, the auxiliary tooling 12 for centering the thin-walled shell with a large length-to-diameter ratio rotates together with the shell 11 to ensure that the rotation axis of the aluminum outer bushing 1 is coaxial with the rotation axis of the shell 11, thus completing the precise correction of the auxiliary tooling 12 for centering the thin-walled shell with a large length-to-diameter ratio.

[0077] After the precise calibration of the auxiliary tooling 12 for the central frame of the thin-walled shell with a large length-to-diameter ratio is completed, the central frame 13 can be installed on the outer circle of the aluminum outer bushing 1 using a three-point support method to achieve auxiliary support for the middle part of the shell 11.

[0078] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention based on the above disclosure without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A central support tooling for a thin-walled shell with a large aspect ratio, characterized in that: From the inside out, it consists of an aluminum semi-circular ring (9), a steel semi-circular ring (4), and an aluminum outer bushing (1). The aluminum semicircular rings (9) are two in number, which encircle the outer circle of the shell (11) to form the first complete circle; The steel semicircular rings (4) are two in number, encircling the outer circle of the first complete circle to form the second complete circle; The aluminum outer bushing (1) surrounds the outer circle of the second complete circle; The aluminum semicircular ring (9) has two symmetrical aluminum bosses on one end of its outer circular surface. The aluminum bosses are provided with radial threaded holes for connecting the steel semicircular ring (4). The upper and lower outer sides of the steel semi-circular ring (4) are provided with steel boss structures, and the steel bosses are provided with tightening threaded holes in the middle. The tightening threaded hole includes a through hole, a pin hole, and a radially stepped through hole; The through hole is used to connect the two steel semi-circular rings; The pin hole includes an axial positioning pin hole and a radial positioning pin hole, used to position the two steel semi-circular rings (4). The radial stepped through hole is used to connect the two steel semicircular rings (4) and the two aluminum semicircular rings (9). The steel semicircular ring (4) is a thick-walled semicircular ring; the steel semicircular ring (4) is provided with double-row radially staggered threaded holes for installing the tightening bolt (5).

2. The auxiliary tooling for assembling a central frame for a thin-walled shell with a large aspect ratio according to claim 1, characterized in that: The aluminum outer bushing (1) is a thick-walled aluminum ring.

3. The auxiliary tooling for assembling a central frame for a thin-walled shell with a large aspect ratio according to claim 1, characterized in that: The axis of rotation of the first complete circle coincides with the axis of rotation of the housing (11); The axis of rotation of the second full circle coincides with the axis of rotation of the first full circle; The axis of rotation of the aluminum outer bushing (1) coincides with the axis of rotation of the second full circle.

4. The auxiliary tooling for assembling a central frame for a thin-walled shell with a large aspect ratio according to claim 1, characterized in that: The inner circle of the first complete circle is in direct contact with the housing (11) with a clearance fit; the inner circle of the second complete circle is in clearance fit with the outer circle of the first complete circle; and the inner circle of the aluminum outer bushing (1) is in transition fit with the outer circle of the second complete circle.

5. The auxiliary tooling for assembling a center frame for a thin-walled shell with a large aspect ratio according to claim 1, characterized in that: The steel semicircular ring (4) and the aluminum semicircular ring (9) are connected by screws (8); the two steel semicircular rings (4) are positioned by radial positioning pins (6) and axial positioning pins (2), and are fastened by fastening bolts (7) and fastening nuts (3).

6. The auxiliary tooling for assembling a center frame for a thin-walled shell with a large aspect ratio according to claim 1, characterized in that: The steel semicircular ring (4) is tightened to the aluminum semicircular ring (9) by the tightening bolt (5) through the double-row radially interlaced threaded holes reserved on the thick-walled semicircular ring in the middle of the steel semicircular ring (4).

7. The auxiliary tooling for assembling a central frame for a thin-walled shell with a large aspect ratio according to claim 1, characterized in that: By adjusting the tightening bolt (5) installed on the steel semi-circular ring (4), the second full-circle rotation axis and the rotation axis of the housing (11) are initially aligned.

8. The auxiliary tooling for assembling a center frame for a thin-walled shell with a large aspect ratio according to claim 1, characterized in that: After each installation, the outer circle of the aluminum outer bushing (1) needs to be machined to ensure that its rotation axis is coaxial with the rotation axis of the housing (11), so as to achieve precise alignment between the rotation axis of the auxiliary tooling (12) for the large length-to-diameter ratio thin-walled housing and the rotation axis of the thin-walled housing (11).

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