CN-121972914-A - Nuclear island driving rod integrated processing and manufacturing method

CN121972914ACN 121972914 ACN121972914 ACN 121972914ACN-121972914-A

Abstract

The invention discloses an integrated processing and manufacturing method of a nuclear island driving rod, which adopts a turning and milling compound host machine, a feeding mechanism and a discharging mechanism; the turning and milling compound main machine is provided with a positive main shaft and a secondary main shaft, upper part the discharging mechanisms are respectively arranged at the outer sides of the axial direction of the discharging mechanisms. The machining method comprises the steps of S1, preparing before machining, S2, feeding and rough machining the right end of a workpiece, S3, finish machining the right end of the workpiece, S4, milling the right end of the workpiece, S5, carrying out outer circle segmented machining, namely driving the workpiece to axially and precisely move through full closed loop control of an auxiliary main shaft, synchronously driving the auxiliary main shaft and the auxiliary main shaft, segmentally turning all outer circle annular grooves, adopting a supporting component capable of automatically stretching in the axial direction to solve the problem of machining vibration of a long overhanging section, S6, machining the left end of the workpiece, S7, blanking, S8, and cleaning after machining. The invention realizes the integrated processing of all turning and milling procedures of the ultra-fine long nuclear island driving rod under one-time clamping, and greatly improves the processing precision, efficiency and quality stability.

Inventors

LI XIAOJUN
ZHANG XINYI
WU GUANGTAO
YANG HUI
CHEN ZHENG
GUO YUNQIANG
LUO CHUANYOU
DENG LONG
LI ZHIQIANG
LI HONGLIN
HUANG CHAO

Assignees

东方电气集团东方汽轮机有限公司

Dates

Publication Date: 20260505
Application Date: 20260202

Claims (7)

1. The integrated processing and manufacturing method for the nuclear island driving rod is characterized by comprising a turning and milling compound main machine, a feeding mechanism and a discharging mechanism, wherein the turning and milling compound main machine is provided with a positive main shaft and a secondary main shaft which are opposite in the axial direction and are arranged at intervals, the feeding mechanism is arranged on the axial outer side of the positive main shaft, and the discharging mechanism is arranged on the axial outer side of the secondary main shaft, and the method is characterized by comprising the following steps: s1, checking and cleaning before machining, namely checking the sizes of an inner hole and an outer circle of incoming materials, cleaning the surface of a workpiece, and loading the workpiece into a feeding mechanism; S2, feeding and rough machining, namely pushing the right end of the workpiece into the front main shaft end from the feeding mechanism, clamping the workpiece on the front main shaft, enabling the right end surface of the workpiece to extend out of the front main shaft by 100mm, and supporting the rest length of the workpiece by the feeding mechanism; s3, finishing one end, namely finishing the machining of deep holes, inner grooves, outer circular grooves and chamfers at the right end of the workpiece; S4, milling, namely controlling the positioning angle of the positive main shaft, and mounting a milling cutter on the milling main shaft to complete the whole milling content of the right end of the workpiece; S5, outer circle segmentation processing, namely stopping moving when the auxiliary main shaft moves towards the end face of the positive main shaft and approaches the end face of the positive main shaft, clamping a workpiece by the auxiliary main shaft, loosening the workpiece by the positive main shaft and a supporting part of a feeding mechanism, and driving the workpiece to axially move to a preset position by the auxiliary main shaft; after moving in place, the supporting parts of the positive main shaft, the feeding mechanism and the discharging mechanism clamp the workpiece, and the automatic and accurate movement of the workpiece is completed; The positive main shaft and the auxiliary main shaft synchronously drive the workpiece to rotate, the tool rest moving main body is provided with a turning tool, and a ring groove on the outer circular surface of the workpiece between the positive main shaft and the auxiliary main shaft is processed under the driving of the rest linear shafts; the outer ring groove of the workpiece is processed section by section in the mode until all the ring grooves on the outer circle of the workpiece are processed; S6, processing the other end, namely automatically driving the workpiece to move towards the end of the blanking mechanism by the auxiliary spindle until the left end face of the workpiece extends out of the left end face of the auxiliary spindle by 100mm; The auxiliary main shaft drives the workpiece to integrally move to the rightmost end of the turning and milling compound main machine, the auxiliary main shaft and a supporting part of the blanking mechanism fix the workpiece, and all excircles and inner holes of the left end of the workpiece are machined; s7, blanking, namely loosening a workpiece by the auxiliary main shaft and a supporting part of a blanking mechanism, and removing the workpiece from a blanking end and hanging the workpiece away from a machine tool; and S8, cleaning the workpiece after machining until the technical requirements are met, and finishing the whole machining of the workpiece.
2. The method according to claim 1, wherein in step S5, when the auxiliary spindle drives the workpiece to move axially, a fully closed loop control system is adopted, and the positioning precision and the repeated positioning precision are less than or equal to 0.004mm.
3. The method according to claim 1, wherein in step S5, the spacing between the primary and secondary spindles is not more than 750mm when ring groove processing is performed.
4. The method according to claim 1, wherein one end of the blanking mechanism facing the auxiliary main shaft is provided with a telescopic supporting component capable of automatically stretching axially; In step S5, when the processing position is located at the workpiece section between the auxiliary main shaft and the blanking mechanism, the telescopic supporting component capable of automatically stretching axially is configured to automatically stretch out according to a program instruction during processing so as to provide auxiliary support for the workpiece located between the auxiliary main shaft and the blanking mechanism, and can automatically retract to make room for the next axial movement of the workpiece when the workpiece needs to move axially.
5. The method according to claim 4, wherein the telescopic travel of the telescopic support member is greater than or equal to 600mm, and the movements thereof are precisely controlled by a numerical control program.
6. The method of claim 1, wherein in step 3, the deep hole is drilled using gun drilling, and the remaining margin of the inner diameter after drilling is reamed three times to remove.
7. The method according to claim 1, wherein in step S2, the rough machining comprises rough turning of the total length of the workpiece, and the reserved machining allowance is 3-5mm.

Description

Nuclear island driving rod integrated processing and manufacturing method Technical Field The invention belongs to the field of machining, and particularly relates to an integrated machining and manufacturing method of a nuclear island driving rod. Background The driving rod of the nuclear island control rod driving mechanism is an slender shaft workpiece with the length-diameter ratio reaching 1:150 times, the outer circle of the slender shaft workpiece is provided with 260 annular grooves, the error of the groove distance is smaller than 0.01mm, the inner structure comprises phi 13-phi 22mm through holes, two-end stepped inner holes, external threads and the like which are used for being connected with other structures, and the straightness, coaxiality, length and groove distance of the workpiece are extremely high. Slender shaft machining is a typical problem in the mechanical manufacturing industry, is limited by the thermal expansion coefficient, shape and rigidity of workpiece materials, has a length-diameter ratio of 30 times and a machining difficulty coefficient of high, and is a slender shaft workpiece with a length-diameter ratio of more than 150 times, and a plurality of factors such as a manufacturing process, operators, equipment, cutters, auxiliary supports, a cooling system, a measuring method and environment are key factors influencing the quality of the workpiece. The requirements on the size, form and position tolerance and surface roughness of the driving rod of the nuclear island control rod driving mechanism are extremely high, and workpieces which do not meet the requirements of drawing paper are scrapped. The current machining method of the nuclear island driving rod mainly adopts turning and milling procedures to finish machining work. The turning working procedure mainly comprises two modes: The workpiece is axially fixed, a plurality of groups of center frames and an excessive support sleeve clamp workpiece are arranged, the main working principle is that a special slender rod lathe and a plurality of center frames are adopted for supporting and clamping the workpiece, the workpiece is driven by a lathe spindle to do rotary motion and does not do axial movement, the center frame supporting position is moved after a section of annular groove is processed, and the adjacent annular groove area is reprocessed until the working content of all turning procedures is finished (figure 1). The workpiece is axially moved, namely, an automatic feeding mechanism is added with double fixed spindles to clamp the workpiece, the main working principle is that a double-spindle special lathe is adopted to support and clamp the workpiece, the workpiece is driven by a lathe spindle to rotate, the workpiece is supported by the feeding devices at the two ends of the lathe and axially moves, after a section of annular groove is machined, the feeding device moves the workpiece to position, the adjacent annular groove is reprocessed until the excircle machining working content of the turning procedure is finished (figure 2), and then deep holes at the two ends are machined by adopting other lathes (figure 3). As shown in fig. 4, the milling process is performed by using a vertical machining center after the turning process is completed. The current processing method of the nuclear island driving rod mainly has the following problems: (1) The special slender shaft turning equipment is used, the equipment has no tool magazine, the skill level requirement of operators is high, the tools are required to be frequently replaced and assembled, programs and manually adjusted in the operation process for tool compensation, the labor intensity is high, the production efficiency is low, the operation errors are more, and the quality stability of workpieces is poor; (2) When the special slender shaft turning equipment is used for machining the workpieces in an axial fixed turning mode, a group of center frames are needed to serve as auxiliary supports at intervals of 10 times of the diameter length positions, the whole workpiece needs to be supported by more than 15 groups of center frames in an auxiliary mode, and the number of the center frames is large. Because of the structural factor of the equipment, the center frame for supporting the workpiece is required to bear the cutting component force, so that a transition sleeve is required to be arranged at each center frame position to protect the outer circle of the workpiece from being damaged, when an outer circular groove is machined, the outer circle transition protective sleeve at the center frame is required to be frequently moved, the auxiliary time of each movement is longer, and the machining efficiency of the workpiece is low; (3) When the special slender shaft turning equipment is used for machining deep holes at two ends of a driving rod, 12 kinds of cutters are needed, the cutter is limited by the cutter frame structure of a machine tool and the shape of