CN106424287A

CN106424287A - Stepwise precise spin-forming process method for large thin-wall dome

Info

Publication number: CN106424287A
Application number: CN201611194740.9A
Authority: CN
Inventors: 李新和; 易兆祥; 常士武; 周磊; 饶国举; 曹权; 魏准; 张坦
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2016-12-22
Filing date: 2016-12-22
Publication date: 2017-02-22

Abstract

The invention relates to a stepwise precise spin-forming process method for a large thin-wall dome. The stepwise precise spin-forming process method comprises the steps that a cone part shearing and spinning process is adopted, specifically, a plate is subjected to spinning to form a cone part through the shearing and spinning process, large-displacement deformation of a plate billet is achieved under the plane-to-cone shearing deformation condition, and the plate billet is changed into a cone from a plane; and secondly, a multi-pass ordinary spinning process is adopted, specifically, the cone part formed in the first step is annealed and fixed to a spherical mandrel, the cone part rotates along with rotation of the spherical mandrel, two rotary wheels are fed to squeeze the cone part in the generatrix direction of the spherical mandrel from the periphery to the center, the cone is increasingly approximating a complex curved surface through the multi-pass spinning process, small-displacement precise forming of the dome is achieved, and the high-precision large dome is finally formed. According to engineering, the stepwise precise spin-forming process method for the large thin-wall dome can be used for achieving integral forming of the dome, the cask effect of welding joints is eliminated, and the carrying capacity of the dome is improved; the weight of the dome can be lowered, and light weight manufacturing of the dome is achieved; and the wall thickness of the dome is uniform, and high-precision forming is achieved.

Description

The substep accurate spinning forming process method of large thin-wall sphere end socket

Technical field

The present invention relates to the substep accurate spinning forming process method of large thin-wall sphere end socket.

Background technology

One national space probation ability, No. 5 fire of the Long March developed depending on the bearing capacity of its carrier rocket, China Arrow, its a diameter of 5.25m, near-earth carrying capacity is 25 tons, and following manned moon landing, the aerospace engineering such as mars exploration requirement rocket Carrying capacity reach hundred tonnes, the carrier rocket of this heavy rank is it is desirable to its rocket body diameter reaches 8-12m.Fuel tank As carrier rocket primary structural members, it is the primary load bearing structure of rocket, Service Environment is extremely harsh, tank thin-wall construction Bear greatly intrinsic pressure, the maximum dynamic loading born more than 10000t, as little as -253 °C of operating temperature, Flight Acceleration reaches 2- 6g, therefore proposes high requirement to its high-performance, high accuracy and lightweight aspect.

For fuel tank sphere end socket, because it has big radius-thickness ratio, weak rigidity, held using traditional diamond-making technique Deformation phenomenon easily occurs, leads to end socket part unstability, promote machining accuracy to be difficult to meet the requirement of aerospace industry.Accelerate thin The research of wall lightweight structure part monolithic molding technology is very urgent, and the Journal of Sex Research achievement that makes a breakthrough is to China's aerospace industry development Most important.

1st, lobe stretch bending welding is divided to shape

Divide lobe welding forming technology to shape thought using " breaking the whole up into parts ", 6～8 pieces of points of lobes will be divided into by an end socket, rush one by one Pressure or pull-shaped obtain each point of lobe, then pass through group weldering by shape divide a lobe welding become an integrated head.Fig. 1 is to be spelled using point lobe It is welded into the end socket schematic diagram of shape, domestic application divides the fuel tank end socket of lobe welding forming technology processing, its maximum gauge reaches 5.25m, is applied to No. 5 rockets of the Long March.

But this process there is also weak point：Welding structure low intensity, poor reliability；Forming head residual stress Greatly, deform big, precision low；Need larger thickness it is impossible to realize lightweight manufacture, affect rocket flight distance.

2nd, conventional spinning shapes

It is that plate or precut blanks are fixed on core that conventional spinning shapes, and drives core with workpiece simultaneously by main shaft gyration Rotate, stress on blank using spinning roller so as to gradually be close to core, thus obtaining the metal forming of required symmetrical casting Method.Fig. 2 is mould pressing schematic diagram.

This technique has the disadvantage that：The easy unstability of large-diameter seal head spinning, wall thickness deviation reaches more than 30%（Thick middle Thin edge）；Milling is needed or using mechanical milling, this technique can lead to seal head material fault of construction or high remaining after therefore shaping Stress, workpiece produces additional deformation, and final precision is uncontrollable.

Content of the invention

For the deficiency of above-mentioned manufacturing process, this seminar has simultaneously obtained big footpath by the research to Forming Equipments, application The high patent rushed rotation shaped device than end socket and rush rotation method of thickness rate longbow（Notification number CN104275378A）.

Patent of the present invention is on the basis of original patent, it is further proposed that substep accurately spinning forming process method,

This forming technology is described in detail below：

The first step：Workpiece is spun into by Tapered Cup by shear spinning technique, plane is configured to the conical surface under the conditions of detrusion, Achieve slab big displacement deformation, heavy slab is configured to Tapered Cup by plectane.

The typical characteristic of cone shear spinning is to meet sinusoidal rule, i.e. blank wall thickness and product wall thickness during shear spinning Relation：（T is the wall thickness of product after spinning, t₀For the wall thickness of blank, it is semi-cone angle).According to bodies such as Plastic Deformation of Metal Materials Long-pending principle, the unit rectangular area abcd of blank is equal with the parallelogram area a ' b ' c ' d ' after deformation, half cone Angle is definite value, so Tapered Cup uniform wall thickness.

Second step：Multi-pass conventional spinning technique, sets up on cone shear spinning Process ba- sis, multi-pass commonly revolves Blanket used in pressure technique is the Tapered Cup of annealing.Tapered Cup flange and flange portion are fixed, by spinning roller Tapered Cup is made to be spun into spherical seal head with spherical core collective effect.For the theory of metal plastic deformation, this by boring Complex-curved thin tail sheep deformation is approached in face, and in forming process, ess-strain is less, it is possible to reduce the defect of thin-walled vessel head cracking, And thin tail sheep stabilization, material flowing is in order, it is possible to increase the forming quality of workpiece.

Multi-pass conventional spinning device is as shown in Figure 6.Tapered Cup 62 external diameter flange is passed through annular pressing plate 63 and bolt 72 It is fixed on spherical core 61 end face, Tapered Cup flange is clamped in spherical core 61 inner face by tensioner 65.In spinning mistake Cheng Zhong, Tapered Cup, tensioner and spherical core random bed main shaft do synchronous rotary motion, spinning roller 64 and spherical core rotary shaft Form an angle, do feed motion along spherical core generatrix direction ecto-entad.Work piece contact zone is in the internal phase of spinning roller and core Produce plastic deformation under interaction, ultimately form sphere end socket with spinning roller propulsion.Which adopts inside and outside constraint cooperation to control, and protects Hinder workpiece directional deformation.

The present invention has following superiority：1）Dome head global formation be can achieve on engineering, eliminate the short slab of weld seam Effect, improves the bearing capacity of end socket；2）End socket weight can be mitigated, realize end socket lightweight manufacture；3）Forming head wall thickness Uniformly, it is possible to achieve high-accuracy shaping.

Brief description

Fig. 1 is the end socket schematic diagram being shaped using point lobe welding,

Fig. 2 is that conventional spinning shapes schematic diagram,

Fig. 3 is that first step cone shear spinning shapes schematic diagram,

Fig. 4 is Tapered Cup wall thickness schematic diagram,

Fig. 5 is that end socket part multi-pass conventional spinning shapes schematic diagram,

Fig. 6 is multi-pass conventional spinning schematic device,

Fig. 7 is cone shear spinning workpiece final molding schematic diagram,

Fig. 8 is sphere end socket flow formed part final molding schematic diagram,

Fig. 9 is that sphere end socket multi-pass conventional spinning shapes Roller locus figure.

Specific embodiment

The substep accurate spinning forming process method of the large thin-wall sphere end socket of the present invention, comprises the following steps that：

The first step：Workpiece rotation is made by Tapered Cup by shear spinning technique, plane is configured to the conical surface under the conditions of detrusion, Achieve slab big displacement deformation, heavy slab is configured to Tapered Cup by plectane.

Cone shear spinning shapes

Tapered core mold materialss adopt 45# steel, and to work conical surface Quenching Treatment, core semi-cone angle is 50 ° it is ensured that its case hardness Reach more than 50HRC.For ensureing the precision of drip molding, the tapered core mould work surface surface roughness of design is Ra=3.2um.

As shown in fig. 7, be fixed on taper core 74 workpiece 71 by bolt 72 and clamping disk 73 cooperation, workpiece is with cone Shape core rotates, and two spinning rollers 64 feed extruding workpiece to surrounding along taper core generatrix direction from center respectively, gradually form Tapered Cup 62.

Second step：Multi-pass conventional spinning technique.Tapered Cup is configured to by spherical seal by multi-pass conventional spinning technique Head, Tapered Cup is gradually approached complex-curved under multi-pass conventional spinning molding condition by the conical surface, realizes sphere end socket thin tail sheep Accurate Shaping, Tapered Cup is spun into spherical seal head.

Sphere end socket mould pressing

Spherical core 82 inner surface is to shape work surface, and therefore surface hardening, to 52HRC, requires its surface roughness to reach simultaneously 3.2um.Outer end end face is uniformly distributed the equal cloth hole of 6 Φ 9, with flanging ring fiting constraint workpiece flange；Internal end surface is uniformly divided 4 M6 screwed holes of cloth, with clamping disk fiting constraint workpiecc lug side.

As shown in Fig. 8, the Tapered Cup 62 that the first step is shaped makes annealing treatment, and Tapered Cup flange and flange portion are respectively With annular pressing plate 63 with step up disk 73 and bolt 72 cooperation be fixed on spherical core, Tapered Cup rotates with spherical core, two Spinning roller 64 feeds extruding Tapered Cup from four circumferences centrally along spherical core generatrix direction respectively, through multi-pass spinning technique, Create into high-precision large spherical surface end socket 81 eventually.

Multi-pass Roller locus figure as shown in figure 9, front two passage spinning do not paste the expanding bulging of spherical core for Tapered Cup, 3rd passage spinning Tapered Cup is close to spherical core, is finally to shape passage.

Claims

1. the substep of large thin-wall sphere end socket accurate spinning forming process method is it is characterised in that include

Step one：Workpiece rotation is made by Tapered Cup by shear spinning technique, plane is configured to the conical surface under the conditions of detrusion, Achieve slab big displacement deformation, heavy slab is configured to Tapered Cup by plectane,

Step 2：Tapered Cup is configured to by sphere end socket by multi-pass conventional spinning technique, Tapered Cup is commonly revolved in multi-pass Gradually approached by the conical surface complex-curved under the conditions of pressing formation, realize sphere end socket thin tail sheep Accurate Shaping, Tapered Cup spinning balling-up Face end socket part.

2. the substep of large thin-wall sphere end socket accurate spinning forming process method is it is characterised in that the concrete mistake of described step one Cheng Wei：Workpiece is fixed on taper core, workpiece rotates with taper core, two spinning rollers respectively from center to surrounding along taper Core generatrix direction feeding extruding workpiece, gradually forms Tapered Cup.

3. the substep of large thin-wall sphere end socket accurate spinning forming process method is it is characterised in that the concrete mistake of described step 2 Cheng Wei：The Tapered Cup that step one is shaped makes annealing treatment, and Tapered Cup is fixed on spherical core, Tapered Cup is revolved with spherical core Turn, two spinning rollers feed extruding Tapered Cup from four circumferences centrally along spherical core generatrix direction, respectively through multi-pass spinning work Skill, forms large spherical surface end socket.