Non-rotational symmetric thickness core rod for bending spaceflight ultra-thin wall pipe

Abstract

The utility model discloses a non-rotational symmetrical thickness core rod for spaceflight ultrathin wall pipe bending, and belongs to the field of pipe fitting bending forming. The problems of forming defects such as serious wall thickness reduction and wrinkling during bending forming of an existing ultrathin-wall pipe are solved. The core rod comprises a core shaft and a non-rotational symmetric thickness core ball. The core ball body is integrally manufactured, but the thickness of the outer side and the thickness of the inner side are different, the small thickness is arranged on the bent outer side, and the large thickness is arranged on the bent inner side. The front end and the rear end of the core ball body are provided with insertion piece head installation grooves and insertion piece tail installation grooves, and the insertion piece head and the insertion piece tail can be fixedly connected with the core ball body through bolt and nut connection. The insertion piece head and the insertion piece tail are provided with pin shaft mounting holes, and the connection between a plurality of core balls with non-rotational symmetrical thicknesses and the connection between the core balls with non-rotational symmetrical thicknesses and the core shaft can be realized through pin shaft assembly. The device is simple in structure, the forming quality of the spaceflight ultra-thin-wall bent pipe can be improved, the production success rate is increased, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of tube bending and forming, in particular to a non-rotationally symmetrical thickness mandrel for bending aerospace ultra-thin wall tubes. Background Art

[0002] At present, metal hollow pipe bends are widely used in the field of aerospace manufacturing. Improving the forming quality of ultra-thin wall pipe bends plays an important role in improving production efficiency and ensuring the working stability of pipe fittings. However, due to the hollow structure of the pipe, various forming defects are prone to occur during the bending process, including: wall thickness reduction, bending cracks, wrinkling, cross-sectional distortion, collapse, etc. In order to improve the forming quality of the pipe bend, a mandrel is usually placed in the pipe as a support to reduce or avoid the above defects.

[0003] According to the actual situation, the thickness of the core ball has a great influence on the forming quality: when the thickness of the core ball increases, the contact surface between the core ball and the outer tube of the bend increases, the friction increases, and the wall thickness thinning intensifies, but it can inhibit wrinkling of the tube on the inner side of the bend; when the thickness of the core ball decreases, the contact surface between the core ball and the outer tube of the bend can be reduced, thereby reducing the wall thickness thinning rate, but due to insufficient constraints, wrinkling is prone to occur on the inner side of the tube bend. In other words, when the core ball thickness adopts a uniform rotationally symmetrical thickness, the forming quality of the outer and inner sides of the bend cannot be guaranteed at the same time. Utility Model Content

[0004] In response to the problems raised in the background, this paper proposes a non-rotationally symmetric thickness mandrel for bending ultra-thin wall tubes in aerospace, which is mainly composed of a mandrel, a non-rotationally symmetric thickness core ball and a connector. The mandrel and the non-rotationally symmetric thickness core ball, as well as the non-rotationally symmetric thickness core balls and the non-rotationally symmetric thickness core balls can be freely assembled, which is easy to adjust and can reduce production costs.

[0005] In order to take into account the forming quality of both the outer and inner sides of the pipe bend, the non-rotationally symmetrical thickness core ball is set with a small thickness on the outer side of the bend and a large thickness on the inner side of the bend. This design can ensure the forming quality of both the inner and outer sides of the pipe bend, and reduce the risk of forming defects such as thinning and cracking of the outer side of the pipe bend and thickening, instability and wrinkling of the inner side of the pipe bend.

[0006] The technical solution adopted by the utility model is as follows:

[0007] A non-rotationally symmetrical thickness mandrel for bending and forming an aerospace ultra-thin wall tube, comprising a plurality of non-rotationally symmetrical thickness core balls, a mandrel and a plurality of sets of connectors;

[0008] The thickness W1 of the curved outer hemisphere and the thickness W2 of the curved inner hemisphere of the non-rotationally symmetrical thickness core ball are non-rotationally symmetrical and equal in thickness, and W1<W2; a concave mounting platform for mounting the plug head and the plug tail is provided in the middle of both sides of the non-rotationally symmetrical thickness core ball, and mounting through holes are provided at both ends of the concave mounting platform, chamfers r2 and r3 are provided on both end surfaces of the curved outer side and the curved inner side of the non-rotationally symmetrical thickness core ball, and a transition section chamfer r4 is provided on W1 and W2 on the tail side of the plug of the non-rotationally symmetrical thickness core ball.

[0009] In the above-mentioned non-rotationally symmetrical thickness mandrel for bending and forming aerospace ultra-thin wall tubes, the mandrel near the tail is a cylinder, the mandrel near the core ball end is a truncated cone, the truncated cone end surface of the mandrel is provided with a mounting groove, and threaded blind holes are provided on both sides of the mounting groove for fixing and installing the insert tail;

[0010] In the above-mentioned non-rotationally symmetrical thickness mandrel for bending and forming aerospace ultra-thin wall tubes, each set of the connectors includes a plug head, a plug tail, a spring washer, a bolt, a nut, a pin, a pin washer and a retaining spring;

[0011] The plug head is a T-shaped structure, a first pin shaft through hole for installing a pin shaft is arranged in the middle of the plug head, and first bolt through holes for installing bolts are arranged at both ends of the plug head; two brackets are arranged in the middle of the plug tail, and second pin shaft through holes for installing a pin shaft are arranged on the two brackets, and second bolt through holes for installing bolts are arranged at both ends of the plug tail;

[0012] The insert tail is fixedly installed in the installation groove of the core shaft by screws;

[0013] The insert head and insert tail are respectively installed on the concave mounting platforms on both sides of the non-rotationally symmetrical thickness core ball, and the spring washer, the insert head, the non-rotationally symmetrical thickness core ball, the insert tail and the spring washer are fixedly connected in sequence by nuts and bolts. The spring washer is used to prevent the fastener from loosening.

[0014] The pin passes through the pin gasket, the insert tail, the insert head, the pin gasket and the retaining spring in sequence to realize the pin-hinged movable connection between the core ball and the core shaft, and the core ball and the core ball. The pin gasket is used to reduce the surface pressure, the retaining spring is installed in the limit groove at the end of the pin, and the retaining spring is used for limiting.

[0015] Compared with the prior art, the utility model has the advantages of free assembly, convenient adjustment and reduced production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 The utility model is a structural schematic diagram of a non-rotationally symmetrical thickness mandrel for bending and forming an aerospace ultra-thin wall tube.

[0018] Figure 3 It is a structural schematic diagram of a core ball with non-rotationally symmetrical thickness according to the utility model.

[0019] Figure 4 It is a schematic diagram of the explosion structure of the core ball with non-rotationally symmetrical thickness of the utility model.

[0020] Figure 5 It is a schematic diagram of the explosion structure of the core ball with non-rotationally symmetrical thickness of the utility model.

[0021] Figure 6 It is a structural schematic diagram of the mandrel of the utility model.

[0022] Figure 7 It is a structural schematic diagram of the connector of the utility model.

[0023] In the figure, 1. a core ball with non-rotationally symmetrical thickness, 2. a core shaft, 3. a connector, 1101. a mounting through hole, 1102. a concave mounting platform, 201. a mounting groove, 202. a threaded blind hole, 22. a screw, 31. a plug head, 3101. a first bolt through hole, 3102. a first pin through hole, 13. a plug tail, 3201. a second bolt through hole, 3202. a second pin through hole, 33. a spring washer, 34. a bolt, 35. a nut, 36. a pin, 361. a limiting groove, 37. a pin gasket, and 38 a retaining spring. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below according to the accompanying drawings and preferred embodiments, and the purpose and effect of the present invention will become more clear. The present invention will be further described in detail below in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] like Figure 1-7 As shown, the non-rotationally symmetrical thickness mandrel for bending and forming aerospace ultra-thin wall tubes of the utility model comprises a plurality of non-rotationally symmetrical thickness core balls 1, a mandrel 2 and a plurality of sets of connectors 3.

[0026] like Figure 3 , 45, the thickness W1 of the curved outer hemisphere and the thickness W2 of the curved inner hemisphere of the non-rotationally symmetrical thickness core ball 1 are non-rotationally symmetrical and equal, and W1<W2; the middle of the two sides of the non-rotationally symmetrical thickness core ball 1 is provided with a concave mounting platform 1102 for mounting the plug head 31 and the plug tail 32, and the two ends of the concave mounting platform 1102 are provided with mounting through holes 1101, and the two end surfaces of the curved outer side and the curved inner side of the non-rotationally symmetrical thickness core ball 1 are both provided with chamfers r2 and r3, and W1 and W2 on the tail side of the non-rotationally symmetrical thickness core ball mounting plug are provided with transition section chamfers r 4， The concave mounting platform 1102 disposed in the middle of both sides of the core ball 1 with a non-rotationally symmetrical thickness can be used to mount the insert head 31 and the insert tail 32, and the distance between the core balls can be adjusted and reduced according to the depth of the concave mounting platform.

[0027] like Figure 6 As shown, the core shaft 2 is cylindrical near the tail and truncated cone near the core ball. A mounting groove 201 is provided on the truncated cone end surface of the core shaft 2, and threaded blind holes 202 are provided on both sides of the mounting groove 201 for fixing and installing the insert tail 32. The insert tail 32 is fixedly installed in the mounting groove 201 of the core shaft 2 by screws 22.

[0028] like Figure 4 , 5 As shown in , 6 and 7 , each set of connectors 3 includes a plug head 31 , a plug tail 32 , a spring washer 33 , a bolt 34 , a nut 35 , a pin 36 , a pin washer 37 and a retaining spring 38 .

[0029] like Figure 4 , 5 As shown, the insert head 31 is a T-shaped structure, with a first pin shaft through hole 3102 for installing the pin shaft 36 in the middle, and first bolt through holes 3101 for installing the bolt 34 at both ends; the insert tail 32 is a similar Π structure, with two brackets provided in the middle, and second pin shaft through holes 3202 for installing the pin shaft 36 are provided on the two brackets, and second bolt through holes 3201 for installing the bolt 34 are provided at both ends. The insert head 31 and the insert tail 32 are respectively installed on the concave installation platform 1102 on both sides of the non-rotationally symmetrical thickness core ball 1, and the spring washer 33, the insert head 31, the non-rotationally symmetrical thickness core ball 1, the insert tail 32, and the spring washer 33 are fixedly connected in sequence by nuts 35 and bolts 34. The spring washer 33 can prevent the loosening of the fastener.

[0030] like Figure 7 As shown, the pin 36 passes through the pin gasket 37, the insert tail 32, the insert head 31, the pin gasket 37 and the snap ring 38 in sequence to achieve a movable connection, and realize the pin articulation of the core ball and the core shaft, and the core ball and the core ball. The pin gasket 37 can reduce the surface pressure, and the snap ring 38 is installed in the limit groove 361 at the end of the pin for limiting.

[0031] The following is the installation process of the non-rotationally symmetrical thickness mandrel for bending and forming the aerospace ultra-thin wall tube of the utility model.

[0032] First, the components of the connector 3 on both sides of the core ball 1 with a non-rotationally symmetrical thickness are separately installed. Figure 3 , 4 As shown, the insert head 31 and the insert tail 32 are respectively installed on the concave installation platform 1102 on both sides of the non-rotationally symmetrical thickness core ball 1, and the spring washer 33, the insert head 31, the non-rotationally symmetrical thickness core ball 1, the insert tail 32, and the spring washer 33 are fixedly connected in sequence by nuts 35 and bolts 34. The spring washer 33 can prevent the fastener from loosening.

[0033] Then install the parts of the connector 3 on the end face of the mandrel 2 separately. Figure 5 As shown, the insert tail 32 is fixedly installed in the installation groove 201 of the core shaft 2 by means of screws 22 .

[0034] like Figure 7 The figure shows the process of installing the hinge of the core ball 1 with a non-rotationally symmetrical thickness and the core shaft 2. The pin 36 is passed through the pin washer 37, the insert tail 32, the insert head 31, the pin washer 37 and the retaining spring 38 in sequence to achieve a movable connection, and realize the pin hinge of the core ball and the core shaft, and the core ball and the core ball. The pin washer 37 can reduce the surface pressure, and the retaining spring 38 is installed in the limit groove 361 at the end of the pin for limiting.

[0035] Those skilled in the art can understand that the above are only preferred examples of the utility model and are not intended to limit the utility model. Although the utility model is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. Non-rotationally symmetrical thickness mandrel for bending ultra-thin wall tubes in aerospace, characterized in that: It comprises a plurality of core balls (1) with non-rotationally symmetrical thickness, a core shaft (2) and a plurality of sets of connectors (3); The thickness W1 of the curved outer hemisphere and the thickness W2 of the curved inner hemisphere of the non-rotationally symmetrical thickness core ball (1) are non-rotationally symmetrical and equal in thickness, and W1<W2; a concave mounting platform (1102) for mounting a plug head (31) and a plug tail (32) is provided in the middle of both sides of the non-rotationally symmetrical thickness core ball (1), and mounting through holes (1101) are provided at both ends of the concave mounting platform (1102); chamfers r2 and r3 are provided on both end surfaces of the curved outer side and the curved inner side of the non-rotationally symmetrical thickness core ball (1); and transition section chamfers r4 are provided on W1 and W2 of the non-rotationally symmetrical thickness core ball (1) on the side where the plug tail (32) is mounted.

2. The non-rotationally symmetrical thickness mandrel for bending aerospace ultra-thin wall tubes according to claim 1, characterized in that: The core shaft (2) is cylindrical near the tail, and is truncated cone near the core ball end. A mounting groove (201) is arranged on the truncated cone end surface of the core shaft (2). Threaded blind holes (202) are arranged on both sides of the mounting groove (201) for fixing the insert tail (32).

3. The non-rotationally symmetrical thickness mandrel for bending aerospace ultra-thin wall tubes according to claim 1, characterized in that: Each set of the connecting body (3) comprises a plug head (31), a plug tail (32), a spring washer (33), a bolt (34), a nut (35), a pin (36), a pin washer (37) and a retaining spring (38); The insert head (31) is a T-shaped structure, a first pin shaft through hole (3102) for installing a pin shaft (36) is arranged in the middle of the insert head (31), and first bolt through holes (3101) for installing bolts (34) are arranged at both ends of the insert head (31); two brackets are arranged in the middle of the insert tail (32), and second pin shaft through holes (3202) for installing the pin shaft (36) are arranged on the two brackets, and second bolt through holes (3201) for installing bolts (34) are arranged at both ends of the insert tail (32); The insert tail (32) is fixedly mounted in the mounting groove (201) of the core shaft (2) by means of screws (22); The insert head (31) and the insert tail (32) are respectively mounted on the concave mounting platforms (1102) on both sides of the non-rotationally symmetrical thickness core ball (1), and the spring washer (33), the insert head (31), the non-rotationally symmetrical thickness core ball (1), the insert tail (32), and the spring washer (33) are sequentially fixedly connected by nuts (35) and bolts (34), and the spring washer (33) is used to prevent the fastener from loosening; The pin shaft (36) passes through the pin shaft gasket (37), the insert tail (32), the insert head (31), the pin shaft gasket (37) and the retaining spring (38) in sequence to realize the pin-hinged movable connection between the core ball (1) and the core shaft (2), and between the core ball (1) and the core ball (1). The pin shaft gasket (37) is used to reduce the surface pressure. The retaining spring (38) is installed in the limiting groove (361) at the end of the pin shaft, and the retaining spring (38) is used for limiting.

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