CN120734785B

CN120734785B - A machining center for machining housings

Info

Publication number: CN120734785B
Application number: CN202511255998.4A
Authority: CN
Inventors: 张双阳; 周军; 沈曙光; 王宝剑
Original assignee: Cixi Changhe Sanhe Metal Shell Co ltd
Current assignee: Cixi Changhe Sanhe Metal Shell Co ltd
Priority date: 2025-09-04
Filing date: 2025-09-04
Publication date: 2025-11-04
Anticipated expiration: 2045-09-04
Also published as: CN120734785A

Abstract

The invention provides a machining center for machining a shell, which belongs to the technical field of shell machining equipment and comprises a machine tool, a machining table positioned in the machine tool, a placing plate, a clamping mechanism and a clamping mechanism, wherein the placing plate is arranged on the machining table, the clamping mechanism is arranged on the placing plate and comprises a supporting ring which is rotatably arranged on the placing plate, a plurality of clamping blocks are arranged on the supporting ring, the clamping blocks are connected with a first gear through a rotating shaft penetrating through the supporting ring, the first gear is meshed with a gear ring, the first gear and the clamping blocks are driven to synchronously rotate when the gear ring rotates, the clamping blocks are abutted against or far away from a workpiece, the workpiece is fixed by a fixing device and then rotated, and when a limiting column corresponds to a bottom hole of the workpiece, the limiting column moves upwards for limiting, so that the workpiece mounting difficulty is reduced, the operating efficiency is improved, the surface damage of the workpiece is effectively avoided, and the mechanical abrasion of the positioning column is reduced.

Description

Machining center for machining shell

Technical Field

The invention belongs to the technical field of shell processing equipment, and particularly relates to a processing center for processing a shell.

Background

The machining center for the shell parts is a high-precision numerical control machine tool capable of realizing multi-station centralized machining and is used for efficiently and precisely machining complex structures of the shell parts (such as a mechanical shell, a box body, a pump body, a valve body and the like). Such machining centers are required to meet the stringent requirements of the housing parts for dimensional accuracy, form and location tolerances, and surface quality.

The patent CN113798885B discloses a shell clamp structure and a vertical machining center, the vertical machining center comprises a first tool and a second tool, the first tool comprises a first base, a first mounting column, a front inner support assembly, a rear inner support assembly and a pressing block assembly, the front inner support assembly and the rear inner support assembly are used for propping up the inner wall of a shell blank, the pressing block assemblies are used for pressing the shell blank, the second tool comprises a second base, a second mounting column and a positioning block assembly, the second mounting column is provided with a plurality of mounting holes, the shell blank is partially inserted into the mounting holes, and the positioning block assembly is used for locking the shell blank. The workman only need change the machining processing that two sets of frock can accomplish the casing blank to all can install a plurality of casing blanks simultaneously on first frock and the second frock, can improve work efficiency.

But this above-mentioned technical scheme still has following problem, need place the casing in positioning fixture department and aim at location structure and fix when fixing the casing, frequently place the location when the clamping and not only waste time and energy, make casing and location structure plug repeatedly when artifical placing, rub, lead to location structure surface wearing and tearing, the clearance increases after wearing and tearing, and the positioning accuracy increases along with the use number of times and descends fast.

Disclosure of Invention

The invention aims to provide a machining center for machining a shell, and aims to solve the problem that in the prior art, when the shell is machined and positioned, the surface of a positioning structure is worn due to frequent contact friction of the positioning structure, and the positioning accuracy is affected.

In order to achieve the purpose, the invention provides the following technical scheme that the machining center for machining the shell comprises a machine tool and a machining table positioned in the machine tool, and further comprises:

a placing plate mounted on the processing table;

The clamping mechanism is arranged on the placing plate and comprises a supporting ring rotatably arranged on the placing plate, a plurality of clamping blocks are arranged on the supporting ring, the clamping blocks are connected with a first gear through a rotating shaft penetrating through the supporting ring, the first gear is meshed with a gear ring, the first gear is driven to synchronously rotate with the clamping blocks when the gear ring rotates, the clamping blocks are abutted against or far away from a workpiece, and when the clamping blocks are abutted against the workpiece, the clamping blocks drive the workpiece to synchronously rotate through friction force, and a first torsion spring for resetting the rotation of the supporting ring is arranged on the supporting ring;

The limiting mechanism is arranged in the clamping mechanism, the limiting mechanism comprises a limiting ring which is rotatably arranged on the supporting ring, a lifting frame which can slide up and down is arranged at the bottom of the limiting ring, a limiting column which penetrates through the limiting ring is arranged on the lifting frame, the top of the limiting column is higher than the upper surface of the limiting ring, a spring which is used for pushing the limiting column upwards is arranged on the lifting frame, the position of the limiting column is matched with the position of a bottom hole of a workpiece, and when the clamping mechanism drives the bottom hole of the workpiece to rotate to correspond to the limiting column, the spring can push the top end of the limiting column into the bottom hole of the workpiece.

According to the further technical scheme, the lower bottom surface of the clamping block is flush with the upper surface of the supporting ring and the upper surface of the limiting ring, the bottom of the clamping block is provided with an inclined surface, and when the clamping block rotates, the inclined surface contacts with the top of the limiting column and pushes the limiting column to move downwards.

According to a further technical scheme, through holes are formed in the placing plate, the supporting ring is rotatably installed in the through holes, a supporting frame is arranged at the bottom of the placing plate, the gear ring is rotatably installed on the supporting frame, a second gear is connected to the outer side of the gear ring in a meshed mode, a motor capable of driving the second gear to rotate is arranged on the supporting frame, one end of the first torsion spring is fixedly installed on the supporting frame, and the other end of the first torsion spring is fixedly connected with the supporting ring.

According to the further technical scheme, a through hole is formed in the supporting ring, the limiting ring is rotatably installed in the through hole, the bottom surface of the limiting ring is fixedly connected with a second torsion spring, one end, away from the limiting ring, of the second torsion spring is fixed on the supporting frame, the second torsion spring is used for applying resistance to rotation of the limiting ring, and when the limiting ring rotates, the second torsion spring can be driven to start torsion and accumulation.

According to the technical scheme, a diversion hole is formed in the bottom of the support frame, through grooves and sensing pieces are formed in the inner walls of two sides of the diversion hole, a limiting block sliding along the through grooves is arranged on one side of the bottom of the lifting frame, when the top of the limiting column is flush with the top of the limiting ring, the limiting block is located in the through grooves, the lifting frame can be limited to rotate at the moment, an indicating plate matched with the sensing pieces is arranged on the other side of the bottom of the lifting frame, the sensing pieces detect the position of the limiting column in the bottom hole of a workpiece through the indicating plate, and when the limiting column is inserted into the bottom hole of the workpiece, the limiting block and the indicating plate move to the position above the through grooves, and at the moment, the lifting frame can rotate along with the limiting ring.

According to the further technical scheme, the number of the limiting columns is consistent with the number of bottom holes, which are required to be limited, of the workpiece, and the tops of the limiting columns are arc-shaped surfaces.

According to a further technical scheme, a pressing plate is arranged above the placing plate, two ends of the pressing plate are located right above a workpiece, and a hydraulic cylinder for driving the pressing plate to be far away from or close to the workpiece is arranged on the upper surface of the placing plate.

According to a further technical scheme, the upper surface of the processing table is symmetrically provided with two fixing frames, the fixing frames are rotatably provided with fixing plates for fixing the placing plates, and the fixing frames are provided with driving devices capable of driving the fixing plates to rotate.

According to a further technical scheme, a tool rest 2 and a track 3 are arranged in the machine tool 1 and are used for adjusting and processing the position of a workpiece.

Compared with the prior art, the invention has the beneficial effects that:

1. Through the reciprocates of spacing post, earlier press down spacing post through the work piece when placing the work piece, rotate after fixed the work piece through fixing device, upward move again and carry out spacingly when spacing post corresponds with the work piece bottom hole, reduced the work piece installation degree of difficulty, promote operating efficiency, the rigid impact when will placing simultaneously converts elastic deformation's buffer force, effectively avoids work piece surface damage, reduces the mechanical abrasion of reference column simultaneously.

2. When the clamping block can rotate above the limiting column in the non-working process, the limiting column is protected, and the phenomenon that impurities adhere to the limiting column or rust and corrode after the limiting column contacts air for a long time to influence the positioning accuracy is avoided.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

FIG. 2 is a schematic diagram of an embodiment of the present invention;

FIG. 3 is a schematic view of a fixing device according to an embodiment of the present invention;

FIG. 4 is a transverse isometric cross-sectional view of an embodiment of the invention;

FIG. 5 is an enlarged schematic view of the structure shown at A in FIG. 4;

FIG. 6 is a schematic view of a clamping mechanism according to an embodiment of the present invention;

FIG. 7 is a schematic view of a support ring according to an embodiment of the present invention;

FIG. 8 is a schematic view of a limiting mechanism according to an embodiment of the present invention;

FIG. 9 is a schematic view of a supporting frame according to an embodiment of the present invention;

FIG. 10 is an isometric cross-sectional view of a spacing mechanism in an example embodiment of the invention;

fig. 11 is a schematic structural view of a lifting frame according to an embodiment of the present invention.

The device comprises a machine tool, a tool holder, a tool 2, a tool post, a rail 3, a 4, a processing table, a 41, a fixing frame, a 42, a fixing disc, a 43, a driving device, a 5, a fixing device, a 51, a placing plate, 511, a through hole, 52, a clamping mechanism, 521, a supporting ring, 5211, a first torsion spring, 5212, a through hole, 522, a clamping block, 5221, a rotating shaft, 5222, a first gear, 5223, an inclined plane, 523, a gear ring, 524, a supporting frame, 5241, a guide hole, 5242, a through groove, 5243, a sensing piece, 525, a second gear, 526, a motor, 53, a limiting mechanism, 531, a limiting ring, 5311, a guide hole, 5312, a second torsion spring, 532, a lifting frame, 5321, a limiting post, 5322, a spring, 5323, a limiting block 5324, an indicating plate, 6, a hydraulic cylinder, 7 and a pressing plate.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1-11, the invention provides a machining center for machining a shell, which comprises a machine tool 1, a tool rest 2, a track 3, a machining table 4 and a fixing device 5;

The lathe 1 level is placed subaerial, knife rest 2 sets up inside lathe 1, install multiunit processing cutter on the knife rest 2, and knife rest 2 can fixed axis rotation realize the switching of processing cutter, track 3 installs on lathe 1 and sets up in knife rest 2 below, knife rest 2 can follow inside the reciprocate of lathe 1 and be close to or keep away from track 3, processing platform 4 sets up on track 3, can drive processing platform 4 and remove on horizontal plane through track 3, fixing device 5 installs on processing platform 4, put the work piece on fixing device 5 and fix a position and centre gripping fixed to the work piece, then knife rest 2 moves down and is close to the work piece and adjusts suitable cutter to knife rest 2 bottom and process the work piece.

It should be noted that, the tool rest 2 and the rail 3 are common supporting devices of the machining center, and specific structures are not described again.

Referring to fig. 2, 3 and 4, two fixing frames 41 are symmetrically installed on two sides of the upper surface of the processing table 4, fixing plates 42 are installed on opposite side surfaces of the two fixing frames 41 in a rotating mode, the fixing plates 42 can rotate on the fixing frames 41 in a fixed shaft mode, a placing plate 51 is arranged between the two fixing plates 42, two ends of the placing plate 51 are respectively installed on the two fixing plates 42, a driving device 43 is installed on one side, away from the fixing plates 42, of one fixing frame 41, the fixing plates 42 are driven to rotate together through the driving device 43, the angle of the placing plate 51 is adjusted, and when processing is achieved, the angle adjustment of workpieces is achieved, and processing requirements of different angles are met.

Referring to fig. 3-8, a holding mechanism 52 is disposed on the placement plate 51, two through holes 511 are symmetrically disposed on the placement plate 51, the through holes 511 vertically penetrate through the placement plate 51, the holding mechanism 52 is mounted in the placement plate 51, the holding mechanism 52 includes a supporting ring 521, the supporting ring 521 is coaxially rotatably mounted in the through holes 511, and the supporting ring 521 is axially slid through a sliding chute and slider structure to limit the sliding of the supporting ring 521, and the upper surface of the supporting ring 521 is flush with the upper surface of the placement plate 51. The supporting ring 521 is provided with clamping blocks 522, the clamping blocks 522 are arranged in a long strip shape, the lower bottom surface of the clamping blocks 522 is flush with the upper surface of the supporting ring 521, and in the embodiment, the clamping blocks 522 are four. The bottom of clamping block 522 one side is provided with pivot 5221, and pivot 5221 runs through and installs on the supporting ring 521, and clamping block 522 carries out the dead axle rotation on the supporting ring 521 through pivot 5221, and pivot 5221 bottom is provided with first gear 5222, and first gear 5222 outside meshing is connected with the ring gear 523, and the inside and outside face of ring gear 523 all is equipped with the tooth, and the internal tooth of ring gear 523 all meshes with a plurality of first gears 5222.

The bottom of the placing plate 51 is provided with a supporting frame 524, the gear ring 523 is rotatably arranged on the supporting frame 524, when the gear ring 523 rotates on the supporting frame 524 in a fixed shaft manner, the gear ring 523 can drive the first gear 5222 to synchronously rotate, the outer side of the gear ring 523 is connected with a second gear 525 in a meshed manner, the bottom of the supporting frame 524 is provided with a motor 526, the output end of the motor 526 is fixedly connected with the second gear 525, the second gear 525 is driven by the motor 526 to drive the gear ring 523 and the first gear 5222 to synchronously rotate, one end of the clamping block 522 far away from the rotating shaft 5221 can synchronously rotate inwards to clamp the lower end of a workpiece or rotate outwards to loosen the workpiece, and due to the eccentric arrangement of the rotating shaft 5221 at the bottom of the clamping block 522, the clamping requirements of workpieces with different sizes can be met when the workpieces are fixed, and the contact positions of the clamping blocks 522 are different when the workpieces with different sizes are clamped, so that the abrasion is caused by contact between one position and the workpieces is avoided.

The bottom of the supporting ring 521 is fixedly provided with a first torsion spring 5211, and one end of the first torsion spring 5211 far away from the supporting ring 521 is fixedly arranged on the supporting frame 524. When clamping is started, the supporting ring 521 is limited to rotate under the torsion force of the first torsion spring 5211, the clamping block 522 firstly rotates fixedly and clamps a workpiece, then the second gear 525 continues to rotate, and the rotation of the first gear 5222 is limited due to the existence of the workpiece, so that the gear ring 523 drives the first gear 5222 to revolve when rotating, and then drives the supporting ring 521 and the workpiece to synchronously rotate, so that the first torsion spring 5211 is stressed to twist, when the workpiece needs to be loosened, the second gear 525 firstly drives the supporting ring 521 to rotate to an initial position, and then the workpiece is loosened.

Referring to fig. 4-11, a through hole 5212 is formed in the support ring 521, a limiting mechanism 53 is further disposed on the placement plate 51, the limiting mechanism 53 includes a limiting ring 531 coaxially rotatably mounted in the through hole 5212, the support ring 521 axially slides and limits the limiting ring 531 through a sliding groove sliding block structure, the upper surface of the limiting ring 531 is flush with the upper surface of the support ring 521, a plurality of guide holes 5311 are formed in the limiting ring 531, the number of the guide holes 5311 is consistent with that of holes for limiting workpieces, four guide holes 5311 are formed in the embodiment, a lifting frame 532 is disposed at the bottom of the limiting ring 531, limiting columns 5321 are disposed on the lifting frame 532, the diameters and the number of the limiting columns 5321 are matched with those of the guide holes 5311, and the diameters of the limiting columns 5321 are matched with those of the holes for limiting at the bottom of the workpieces. The limiting column 5321 penetrates through the limiting ring 531 through the guide hole 5311, the limiting column 5321 can slide up and down along the limiting ring 531, a spring 5322 is arranged at the bottom of the limiting column 5321, one end of the spring 5322 is connected with the lifting frame 532, the other end of the spring 5322 is connected with the bottom surface of the limiting ring 531, the lifting frame 532 is tightly attached to the bottom surface of the limiting ring 531 through the tensile force of the spring 5322 in an initial state, and at the moment, the top end of the limiting column 5321 extends out of the upper surface of the limiting ring 531 for limiting a workpiece. The bottom surface of the limiting ring 531 is fixedly provided with a second torsion spring 5312, and one end, away from the limiting ring 531, of the second torsion spring 5312 is fixedly arranged on the supporting frame 524.

During processing, a workpiece is placed on the upper surface of the limiting ring 531, at the moment, the hole position at the bottom of the workpiece is not directly matched with the limiting column 5321, the limiting column 5321 drives the lifting frame 532 to move downwards under the action of the gravity of the workpiece until the top of the limiting column 5321 is flush with the upper surface of the limiting ring 531, at the moment, the spring 5322 is elongated, then the workpiece is fixed through the clamping mechanism 52 and rotates, at the moment, the limiting ring 531 cannot rotate under the torsion action of the second torsion spring 5312, when the hole position at the bottom of the workpiece is aligned with the limiting column 5321, the spring 5322 rebounds to drive the lifting frame 532 and the limiting column 5321 to move upwards, and the limiting column 5321 is inserted into the hole at the bottom of the workpiece to limit the workpiece. The limit post 5321 is prevented from frequently rubbing with the workpiece to accelerate abrasion when the workpiece is installed and positioned. The limiting post 5321 moves upwards to penetrate through the limiting ring 531 to be inserted into a bottom hole of the workpiece, then the limiting ring 531 rotates together, and at the moment, the second torsion spring 5312 starts to bear and twist, and the workpiece is machined. It should be noted that the torsion force of the second torsion spring 5312 is smaller than the friction force between the clamping block 522 and the workpiece, so as to ensure the normal rotation of the limiting ring 531 during processing. When the processing is finished and the workpiece is taken out, the second torsion spring 5312 releases the torsion force and drives the limit ring 531 to rotate to the initial position.

Referring to fig. 4, 9, 10 and 11, a guide hole 5241 is formed at the bottom of the supporting frame 524, a hole corresponding to the guide hole 5241 is formed on the limiting ring 531, cooling liquid or chips can be discharged through the hole on the limiting ring 531 and the guide hole 5241, a through groove 5242 is formed on the inner wall of one side of the guide hole 5241, a limiting block 5323 capable of sliding up and down along the through groove 5242 is formed on one side of the bottom of the lifting frame 532, when the lifting frame 532 moves downwards, a limiting block 5323 can slide in the through groove 5242, a sensing piece 5243 is arranged on the inner wall of the other side of the guide hole 5241, the sensing piece 5243 can be arranged as an infrared sensor, an indicating plate 5324 matched with the sensing piece 5243 is arranged on the other side of the bottom of the lifting frame 532, when the limiting block 5323 slides in the through groove 5242, the indicating plate 5324 corresponds to the sensing piece 5343, and the sensing piece 5343 is used for detecting the position of the lifting frame 532, so as to judge whether the limiting post 5321 is inserted into the workpiece bottom hole. When the limiting post 5321 is completely inserted into the bottom hole of the workpiece, the limiting block 5323 and the indicating plate 5324 move upwards to above the through groove 5242, and at this time, the indicating plate 5324 is disconnected from the sensing piece 5243 for detection, and the limiting block 5323 is separated from the through groove 5242, so that the normal rotation of the lifting frame 532 is ensured.

Referring to fig. 2-4, a hydraulic cylinder 6 is disposed on the upper surface of the placement plate 51, a pressing plate 7 is disposed above the placement plate 51, an output end of the hydraulic cylinder 6 is connected with the bottom surface of the pressing plate 7, two ends of the pressing plate 7 are located right above the workpieces on two sides of the placement plate 51, and the pressing plate 7 is controlled to move downwards to contact with the upper surface of the workpieces to assist in clamping and fixing the workpieces or move upwards away from the workpieces through the hydraulic cylinder 6.

Through the cooperation of the pressing plate 7 and the clamping mechanism 52, after the processing of a certain position of a workpiece is finished, the fixing of the pressing plate 7 is loosened, the angle of the workpiece is adjusted through the clamping mechanism 52, the processing of different positions of the workpiece is realized, and the situation that the position clamping is frequently replaced repeatedly due to the fact that the fixing structure blocks the position to be processed is avoided. Meanwhile, as the clamping mechanism 52 drives the workpiece to rotate, the stress of the first torsion spring 5211 is gradually increased, the clamping force of the clamping block 522 on the workpiece is also gradually increased, the workpiece is prevented from rotating after the part is machined, and the workpiece is prevented from being clamped and loosened due to the fact that the center of gravity of the workpiece is shifted to generate vibration, so that accuracy errors are caused.

Referring to fig. 6 and 11, an inclined plane 5223 is provided at the bottom of the clamping block 522, so that the upper bottom surface of the clamping block 522 is larger than the lower bottom surface, and an arc surface is provided at the top of the limiting post 5321. After the workpiece is taken out, the inclined surface 5223 is contacted with the arc-shaped surface at the top of the limit post 5321 through the rotation of the clamping block 522, the limit post 5321 is pushed downwards, at the moment, the limit block 5323 moves downwards and slides into the through groove 5242, the lifting frame 532 is fixed in an auxiliary mode, and the limit ring 531 is prevented from rotating due to the fact that the thrust is too large when the clamping block 522 rotates. Because grip block 522 bottom surface and placement plate 51 bottom surface parallel and level, can strike off the difficult piece that is cleared up around spacing post 5321 when grip block 522 rotates, use the coolant liquid to wash out the piece that adheres to on the inclined plane 5223 at last. After the cleaning is finished, the clamping block 522 can rotate to the position above the position-limiting column 5321, the position-limiting column 5321 is completely pressed into the position-limiting ring 531, the upper end of the position-limiting column 5321 is sealed, and impurities are prevented from adhering to the surface of the position-limiting column 5321 when the device is not used, so that later use is prevented from being influenced.

Claims

1. Machining center for machining a housing, comprising a machine tool (1) and a machining table (4) located inside the machine tool (1), characterized in that it further comprises:

A placement plate (51), the placement plate (51) being mounted on the processing table (4);

The clamping mechanism (52) is arranged on the placing plate (51), the clamping mechanism (52) comprises a supporting ring (521) rotatably arranged on the placing plate (51), a plurality of clamping blocks (522) are arranged on the supporting ring (521), the clamping blocks (522) are connected with a first gear (5222) through a rotating shaft (5221) penetrating through the supporting ring (521), the first gear (5222) is meshed with a gear ring (523), when the gear ring (523) rotates, the first gear (5222) and the clamping blocks (522) are driven to synchronously rotate, the clamping blocks (522) are abutted against or separated from a workpiece, when the clamping blocks (522) are abutted against the workpiece, the clamping blocks (522) drive the workpiece to synchronously rotate through friction force, and a first torsion spring (5211) for resetting the rotation of the supporting ring (521) is arranged on the supporting ring (521);

The limiting mechanism (53) is installed in the clamping mechanism (52), the limiting mechanism (53) comprises a limiting ring (531) which is rotatably installed on a supporting ring (521), a lifting frame (532) capable of sliding up and down is arranged at the bottom of the limiting ring (531), a limiting column (5321) penetrating through the limiting ring (531) is arranged on the lifting frame (532), the top of the limiting column (5321) is higher than the upper surface of the limiting ring (531), a spring (5322) used for pushing the limiting column (5321) upwards is arranged on the lifting frame (532), the position of the limiting column (5321) is matched with the position of a workpiece bottom hole, and when the clamping mechanism (52) drives the bottom hole of a workpiece to rotate to correspond to the limiting column (5321), the spring (5322) can push the top end of the limiting column (5321) into the inside of the workpiece bottom hole.

2. A machining center for machining a housing according to claim 1, wherein the lower bottom surface of the clamping block (522) is flush with the upper surface of the supporting ring (521) and the upper surface of the limiting ring (531), an inclined surface (5223) is arranged at the bottom of the clamping block (522), and when the clamping block (522) rotates, the inclined surface (5223) contacts with the top of the limiting column (5321) and pushes the limiting column (5321) to move downwards.

3. A machining center for machining a shell according to claim 1, wherein the placement plate (51) is provided with a through hole (511), the support ring (521) is rotatably installed in the through hole (511), the bottom of the placement plate (51) is provided with a support frame (524), the gear ring (523) is rotatably installed on the support frame (524), the outer side of the gear ring (523) is connected with a second gear (525) in a meshed mode, the support frame (524) is provided with a motor (526) capable of driving the second gear (525) to rotate, one end of the first torsion spring (5211) is fixedly installed on the support frame (524), and the other end of the first torsion spring is fixedly connected with the support ring (521).

4. A machining center for machining a shell according to claim 3, wherein the supporting ring (521) is internally provided with a through hole (5212), the limiting ring (531) is rotatably installed in the through hole (5212), the bottom surface of the limiting ring (531) is fixedly connected with a second torsion spring (5312), one end, away from the limiting ring (531), of the second torsion spring (5312) is fixed on the supporting frame (524), the second torsion spring (5312) is used for exerting resistance to rotation of the limiting ring (531), and when the limiting ring (531) rotates, the second torsion spring (5312) can be driven to start torsion and accumulation.

5. A machining center for machining a shell according to claim 3, wherein the bottom of the supporting frame (524) is provided with a guide hole (5241), through grooves (5242) and sensing pieces (5243) are formed in inner walls of two sides of the guide hole (5241), one side of the bottom of the lifting frame (532) is provided with limiting blocks (5323) sliding along the through grooves (5242), when the top of the limiting columns (5321) is flush with the top of the limiting ring (531), the limiting blocks (5323) are located in the through grooves (5242) and can limit the lifting frame (532) to rotate at the moment, the other side of the bottom of the lifting frame (532) is provided with an indicating plate (5324) matched with the sensing pieces (5243), the sensing pieces (5243) detect the positions of the limiting columns (5321) in workpiece bottom holes through the indicating plates (5324), and when the limiting columns (5321) are inserted into the workpiece bottom holes, the limiting blocks (5323) and the indicating plates (5324) move to the positions above the through grooves (5242), and the lifting frame (532) can rotate along with the limiting ring (531).

6. The machining center for machining a shell according to claim 5, wherein the number of the limiting columns (5321) is identical to the number of bottom holes, which are required to be limited, of the workpiece, and the tops of the limiting columns (5321) are arc-shaped.

7. A machining center for machining a shell according to claim 1, wherein a pressing plate (7) is arranged above the placing plate (51), two ends of the pressing plate (7) are located right above a workpiece, and a hydraulic cylinder (6) for driving the pressing plate (7) to be far away from or close to the workpiece is arranged on the upper surface of the placing plate (51).

8. A machining center for machining a housing according to claim 1, wherein two fixing frames (41) are symmetrically installed on the upper surface of the machining table (4), a fixing plate (42) for fixing a placing plate (51) is rotatably installed on the fixing frames (41), and a driving device (43) capable of driving the fixing plate (42) to rotate is arranged on the fixing frames (41).

9. A machining center for machining a housing according to claim 1, wherein a tool rest (2) and a rail (3) are provided inside the machine tool (1) for the position adjustment and machining of a workpiece.