CN114871822B

CN114871822B - Centrifugal force-free cutting device

Info

Publication number: CN114871822B
Application number: CN202210462551.4A
Authority: CN
Inventors: 唐伟; 赖颂文; 梁潮淋; 肖耘亚; 林梓灿; 郭朝浩; 林永浩; 张楷铎; 神翠楠; 唐溢成; 叶木强; 温汝良; 古伟; 叶际英
Original assignee: Shaoguan University
Current assignee: Shaoguan University
Priority date: 2022-04-28
Filing date: 2022-04-28
Publication date: 2023-05-05
Anticipated expiration: 2042-04-28
Also published as: DE102023110674A1; CN114871822A

Abstract

The invention provides a centrifugal force-free cutting device, belongs to the technical field of machining, and is mainly used for turning a weak-rigidity shaft, namely an slender shaft. The cutting device is arranged on the frame and comprises a main shaft, a cutting mechanism positioned at the front end of the main shaft and a driving mechanism positioned at the rear end of the main shaft and used for driving the main shaft to rotate; the main shaft comprises an inner shaft and an outer shaft which are in rotary connection and are driven by an inner shaft motor and an outer shaft motor respectively; the cutting mechanism is driven by the outer shaft to perform circumferential cutting, and the relative differential motion of the inner shaft and the outer shaft is synthesized to realize radial feeding of the cutter. The centrifugal force-free cutting device provided by the invention can reduce the processing deformation of the weak rigidity shaft, reduce the influence of centrifugal force on the processing process, and simultaneously improve the processing quality and the processing efficiency of the weak rigidity shaft; the processing of the weak rigidity shaft is more intelligent and flexible, the operation difficulty of the processing of the weak rigidity shaft is reduced, the technical requirements on operators are reduced, and the processing level of shaft parts is improved.

Description

Centrifugal force-free cutting device

Technical Field

The invention relates to the technical field of machining, in particular to a centrifugal force-free cutting device for a weak-rigidity shaft.

Background

In machining, lathes are the most widely used type, accounting for about 50% of the total number of lathes, and shaft-type parts are the most common type of lathe machining. The weak rigidity shaft is a common type of shaft parts, such as a screw rod, a transmission shaft and the like, and belongs to shaft parts difficult to process. The elongate shaft is typically a weak stiffness shaft, definition of elongate shaft: the ratio of the length to the diameter of the shaft is greater than 25 (i.e., L/D > 25). The slender shaft is usually provided with processing technologies such as turning an outer circle, turning a step, turning threads and the like. In the slender shaft processing, instability caused by centrifugal force can deform and vibrate a workpiece, and the processing precision and the surface quality of the workpiece are reduced, so that the assembly precision and the use precision of the whole machine are reduced.

Conventional slender shaft processing methods generally adopt a lathe method of clamping one by one and matching a center frame or a follower rest for processing. The method using the center frame has the defects of increased machining times, high clamping force control difficulty, non-negligible centrifugal force and low machining efficiency. The slender shaft is machined by the follower rest, the follower rest is easily in contact with the outer circle of the shaft too tightly or too loosely, the cutter vibration phenomenon occurs, the defects of bamboo joint shape, polygon, and the like exist, and the machining quality is affected.

In order to solve the above problems, some scholars have improved the slender shaft process. Liang Manying, etc., are processed by adopting an interpolation mode combining linear interpolation and circular interpolation on the basis of the traditional numerical control processing to eliminate the defects of cone shape and drum shape and improve the processing quality. However, the method is only suitable for numerical control machine tools, and the interpolation functions of different brands of numerical control machine tools are different, so that the application range is narrow. Li Xiaozhou and the like, solves the problem of insufficient contact of the traditional follower rest, and can effectively reduce the workpiece machining vibration through experiments. However, the problem of low machining efficiency of the follower rest cannot be avoided. Wang Na and the like have intensively studied a method for reversely turning an slender shaft based on a pull clamping method, and verified by adopting a simulation analysis method, and the result shows that the bending deformation and vibration of the slender shaft can be effectively reduced. However, the method cannot avoid the influence caused by the defects of the traditional single-tool turning. Hao Chunling outlines the technical points of thread rolling processing, a thread forming hob is utilized to press threads on a workpiece, the power required by the thread hob is high, the rotating speed is low, the contact length is long, radial deformation and vibration of processing are effectively reduced, the efficiency is high, friction force for pressing threads is high, thermal deformation is high, and a large amount of lubricating oil is required to maintain processing. The method for double-cutter turning is researched by wearing harbors and the like, two turning tools are used for simultaneously cutting two sides of a follower rest, so that the machining precision and efficiency are effectively improved, and the unit energy consumption is reduced. Huang Xiaodong and the like, a special machine tool for turning the taper of the slender shaft with double head bands is designed, the machine tool uses a pulling clamping method to replace the traditional clamping scheme of jacking and replacing a follow rest with a follow rest manipulator, and a method of turning two sides simultaneously is adopted, so that the machining rigidity and the machining efficiency of the slender shaft are improved. Dai Haigang and Huang Xiaodong are only improvements of the traditional machine tool processing method and the traditional machine tool, and the problem that centrifugal force vibrates a workpiece is not solved. Wang Peng and the like, a special machine tool for processing the reducing slender shaft is designed, and the processing precision and quality of the reducing slender shaft can be effectively improved. The machine tool still gets rid of the defects of single-tool machining and workpiece rotation. Liu Shunhua outlines the principle of whirling milling, which is a modern advanced processing mode, and the principle of whirling milling threads is to cut a workpiece by eccentrically tilting a milling cutter head at a single side at a high speed and control the feeding amount to form the threads. The disadvantage of whirling milling is that the unilateral cutting of the milling cutter head can deform the workpiece under unidirectional stress. The proposal of three-cutter turning with 120 degrees of difference in plane roundness is researched by wearing harbor and the like, stress analysis is carried out on the proposal, and the simulation analysis of ANASYS software is adopted to obtain the conclusion that the bending deformation of a turned workpiece of the proposal is far smaller than the processing deformation of a traditional lathe. This scheme is only theoretically studied and does not actually verify the authenticity of the theory. Mao Jiangfeng and the like design a double-cutter whirlwind cutter head and a centering chuck which can be arranged on a CA6140 lathe, can realize the machining mode of cutter rotary cutting and workpiece feeding, reduces machining deformation in principle and effectively improves machining precision. However, the double-cutter cyclone cutterhead can only be used for machining a slender shaft with a single diameter, and machining is not flexible enough.

In addition, some foreign scholars have studied the above problems. Wu Mingming and the like research the turning process of the slender shaft by adopting a finite element analysis method, and the research shows that the reverse turning method can improve the machining precision of the slender shaft. In order to reduce trial and error times of selecting optimal technological parameters for machining the slender shaft, mild Azvar and the like, a parallel turning flutter stability multidimensional analysis model is established, and the method can rapidly determine flutter-free and high-productivity cutting conditions and improve slender shaft productivity and machining precision. Tie Ling Wang et al uses Pro/ENGINEER and Pro/MECHANICA software to analyze the influence of different clamping modes on the processing deformation and the natural frequency of the slender shaft, and analyzes and obtains a process scheme for reducing the processing deformation and vibration. Ding Pengfei and the like are used for solving the problems that any slender shaft diameter error can cause cutter abrasion and machining precision to be poor, and a reliability parameter optimization model is established by considering the diameter error, so that the reliability of selecting cutting parameters can be well improved, and the slender shaft machining precision is improved. The Hong Wang et al performs mechanical analysis on the reverse turning technology for machining the slender shaft, establishes a mathematical model, and researches show that the bending deformation and the machining error under the reverse turning condition are far smaller than those of normal turning. The studies of the Wu Mingming, mild Azvar, tie Ling Wang and other scholars are all from the angle of cutting parameters, and an error analysis is carried out by adopting a simulation method, so that the turning processing of an slender shaft is optimized, the processing precision is improved to a limited extent, and the processing problem caused by centrifugal force on a workpiece still cannot be solved. Lian Qing Chen et al have studied an error compensation method based on PID controller, used for compensating the processing error of slender shaft, the experimental result shows that this method can improve the processing accuracy of slender shaft. Guo Jianliang aims at the problem of diameter error caused by dynamic response during slender shaft machining, and a Rayleigh beam theory is adopted to conduct numerical simulation on a turning process, so that a method for measuring the diameter error caused by vibration of a rotating workpiece is obtained. The study by Lian Qing Chen, guo Jianliang et al gives a solution in terms of actual error measurement, but does not substantially solve the problem of centrifugal force affecting the machining, and the improved machining accuracy is likewise limited. Kai Bo Lu et al have studied the dynamic course of turning slender shaft of dual spindle, have analyzed the dynamic response of the rotary workpiece, have discussed the influence of cutting parameter on axial system response and natural frequency, offer the method to improve the machining precision finally. But the method remains only in the theoretical analysis stage. Jin Chun Feng et al research a processing method for turning trapezoidal threads on an elongated shaft, illustrate a method and a way for processing trapezoidal threads on the elongated shaft, and provide experience for high-precision processing of the elongated screw rod. But still cannot be free from the defects of the traditional processing. The Yang Lin et al research the processing process of the variable-diameter slender shaft, designs a machine tool adopting a flexible hydraulic driven piece and an elastic tailstock, and effectively improves the processing precision and the processing quality. The defect of the workpiece rotation processing still exists.

In summary, the above studies have partially addressed the drawbacks that occur in the machining of elongated shafts, but most do not involve the study of multiple-tool symmetrical circumferential and radial cutting, as well as the cutting of workpiece feed.

Disclosure of Invention

In order to solve the technical problems, the invention provides the centrifugal force-free cutting device which converts the rotation of a workpiece into the rotation cutting of a symmetrical cutter, converts the axial feeding of the cutter into the tension feeding, hardly influences the centrifugal force on the workpiece, reduces the vibration during the workpiece processing, avoids the single-side stress of the workpiece, reduces the deformation of the workpiece and can achieve the purposes of improving the processing precision, the processing quality and the processing efficiency.

The technical scheme of the invention is realized as follows:

the centrifugal force-free cutting device is arranged on the frame and comprises a main shaft, a cutting mechanism positioned at the front end of the main shaft and a driving mechanism positioned at the rear end of the main shaft and used for driving the main shaft to rotate; the main shaft comprises an inner shaft and an outer shaft which are in rotary connection and are driven by an inner shaft motor and an outer shaft motor respectively; the cutting mechanism is driven by the outer shaft to perform circumferential cutting, and the relative rotation speeds of the inner shaft and the outer shaft are synthesized to realize radial feeding of the cutter.

Further, the cutting mechanism comprises a base frame arranged at the front end of the outer shaft, a sliding block which is connected with the base frame in a sliding way and provided with arc teeth is arranged on the base frame, and a cutter is fixed on the sliding block; the front end of the inner shaft is provided with a wire coil; the arc teeth on the slide block are meshed with the wire coil, and the cutter feeding or retracting is controlled through the rotation speed difference between the outer shaft and the inner shaft.

Further, a first clamp and a second clamp for clamping the workpiece are respectively arranged at two axial ends of the cutting mechanism.

Further, the second clamp is fixed at the front end of the inner shaft and synchronously rotates with the inner shaft, and the second clamp drives the wire coil to rotate through static connection during rotation.

Further, the second clamp comprises a second base and a movable clamping jaw elastically propped against the base, and the clamping jaw head is provided with a ball which is in contact with the workpiece.

Further, the first clamp is arranged on the first base and is a three-jaw chuck with elastically telescopic clamping jaws, and the end parts of the clamping jaws are provided with rollers; or alternatively, the first clamp is arranged on the first base and comprises a movable clamping jaw elastically propped against the first base, and the clamping jaw head is provided with a ball to be in contact with the workpiece.

Further, the second base is a jaw clutch, and the front end of the inner shaft drives the wire coil to rotate through static connection of the jaw clutch.

Further, a workpiece feeding mechanism is further arranged on the frame, the workpiece feeding mechanism is a self-centering clamp, and after clamping a workpiece, the workpiece is pulled to move along the axial direction, so that workpiece feeding is realized.

Further, the tools are arranged in pairs, and turning positions of each pair of tools are symmetrical.

Further, the inner shaft and the outer shaft are connected through a sliding bearing, and the outer shaft is supported on the frame through a bearing.

The invention has the following beneficial effects:

1. the cutting mechanism is detachable and installed on the spindle head, and can rotate along with the spindle to cut a workpiece. The inner shaft and the outer shaft are driven to rotate by respective driving motors and speed reducing mechanisms, when the outer circle of the fixed diameter shaft is cut, the wire coil and the base frame rotate at the same speed, the relative speed is zero, the cutter is not fed, and the equal diameter cutting is realized; when the stepped shaft, the conical surface and the like are cut, the rotating speed of the wire coil is faster (or slower) than that of the base frame, and a certain rotating speed difference exists between the wire coil and the base frame, so that the variable-diameter cutting is realized. When the rotation speed of the inner shaft and the outer shaft generates a speed difference, a combining mechanism (a wire coil and a sliding block with circular arc teeth) combines the main shaft motion and the radial feeding motion, and the combination mechanism reflects the feeding (or retracting) of a cutter.

2. The even number of the cutting process counteracts the symmetrical forces of the cutters, and the machining process ensures the stress stability of the workpiece and avoids deformation.

3. The first clamp is fixedly arranged on the right side of the cutting mechanism at a certain distance, the second clamp is arranged on the tail end of the main shaft or on the left side of the cutting mechanism, the clamping jaws of the first clamp and the second clamp are designed to be clamping jaws with balls or rollers, the radial clamping can be realized, the axial feeding of a workpiece is not influenced, and the obstruction of the clamping jaws to the workpiece feeding caused by the uneven surface of the workpiece during the axial feeding is overcome.

4. The workpiece axial feeding mechanism adopts a pull clamp mode to feed the workpiece from left to right so as to ensure the rigidity of the shaft during processing.

Drawings

FIG. 1 is a schematic diagram of the motion principle of the present invention;

FIG. 2 is a schematic diagram of the transmission principle of the present invention;

FIG. 3 is a schematic view of the spindle mechanism of the present invention;

FIG. 4 is a cross-sectional view showing the structure of embodiment 1 of the present invention;

FIG. 5 is a cross-sectional view showing the structure of embodiment 2 of the present invention;

FIG. 6 is a cross-sectional view of a second clamp of the present invention;

fig. 7 is a perspective view of a second clamp of the present invention.

In the figure: 1-main shaft, 101-inner shaft, 102-outer shaft, 2-cutting mechanism, 201-base frame, 202 slide block, 203-cutter, 204 wire, 3-driving mechanism, 301-inner shaft motor, 302-outer shaft motor, 4-first clamp, 401-clamping jaw, 402-roller, the clamping device comprises a No. 5 clamp, a No. 501 base, a No. 502 movable clamping jaw, a No. 503 ball, a No. 504 spring, a6 self-centering clamp and a 7 workpiece.

Detailed Description

The following description of the technical solutions in the embodiments of the present invention will be clear and complete, and it is obvious that the described embodiments 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.

Example 1

Referring to fig. 1-4, a centrifugal force-free cutting device is arranged on a frame and mainly comprises a main shaft 1, a cutting mechanism 2 positioned at the front end of the main shaft, and a driving mechanism 3 positioned at the rear end of the main shaft 1 and used for driving the main shaft 1 to rotate; the main shaft 1 comprises an inner shaft 101 and an outer shaft 102, the outer shaft 102 is sleeved outside the inner shaft 101, the inner shaft and the outer shaft can mutually rotate, and the inner shaft 101 and the outer shaft 102 are connected by adopting solid lubrication sliding bearings or bearing bushes due to the lower relative rotation speed of the inner shaft and the outer shaft. Because the type of the processed workpiece is an slender shaft, the feeding amount and the back cutting amount are smaller, and the cutting force is also smaller, the bearing combination selects a speed combination, the front support of the outer shaft 102 is selected from a pair of deep groove ball bearings and thrust ball bearing combinations, the double deep groove ball bearings improve the front support rigidity, and the front support configuration of the thrust ball bearings can reduce the influence of the thermal deformation of the main shaft; the rear support is a pair of angle contact ball bearing combinations, and the anti-overturning capacity of the main shaft is improved by adopting a reverse installation mode.

The inner shaft 101 and the outer shaft 102 are driven by an inner shaft motor 301 and an outer shaft motor 302, respectively; the inner shaft and the outer shaft are respectively connected with the inner shaft motor and the outer shaft motor through respective speed change groups, and the inner shaft 101 needs to cooperate with an electric control system to carry out stepless speed regulation, so that the servo motor is selected as a power source, the rotating speed of the inner shaft 101 can be accurately regulated and controlled, and the cutting feed is realized through the speed difference of the inner shaft and the outer shaft. The internal and external main shaft transmission schemes all select common cylindrical spur gear transmission, and the transmission scheme is simple and reliable and can ensure the rotation precision. As shown in fig. 3 and 4, the outer shaft gear is positioned adjacent the front bearing to reduce the forced deformation of the outer shaft; due to structural limitations, the gears of the inner shaft 101 can only be placed at the tail end, and in order to enhance the rigidity of the tail end of the inner shaft 101, deep groove ball bearings are added on the left and right sides of the gears to serve as supports for the tail end of the inner shaft 101. As shown in fig. 3, the driving mechanisms are arranged at the left and right sides of the main shaft 1, so that the main shaft 1 is prevented from being bent and deformed to one side by one side under the stress.

The cutting mechanism 2 is fixed at the front end of the outer shaft 102 and comprises a base frame 201, a sliding block 202 with arc teeth is arranged on the base frame 201, the sliding block 202 is connected with the base frame 201 in a sliding mode, a cutter 203 is fixed on the sliding block 202, and the cutter 203 is driven by the outer shaft 102 to perform circumferential cutting; the front end of the inner shaft 101 is provided with a wire 204; the arc teeth on the sliding block 202 are meshed with the wire 204, and the cutter 203 is synthetically controlled to feed or retract through the rotation speed difference between the outer shaft 102 and the inner shaft 101.

The outer circle of the bearing bush of the solid lubrication sliding bearing is in interference fit with the inner hole of the outer shaft 102, the outer circle of the inner shaft 101 is in transition fit with the inner circle of the bearing bush with solid lubricant, the inner shaft 101 and the outer shaft 102 can rotate relatively, and power is transmitted through the gears of the inner shaft 101 and the outer shaft 102 to drive the wire coil 204 and the base frame 201 to rotate in a differential mode. The inner shaft gear is arranged at the tail part of the inner shaft 101, the inner shaft 101 is driven to rotate through a key, and a deep groove ball bearing are arranged in front of and behind the gear so as to increase the rigidity of the tail gear close to the shaft. The tail of the inner shaft 101 is reserved with a space for placing an oil pan to convey lubricating oil into a lubrication system. The outer shaft 102 is supported by a support mode that one end is fixed and the other end is free, the front support is fixed by using a sleeve cup, and the rear support is freely arranged on the box body. Because the requirement on the rotation speed of the processing slender shaft is high, the front support adopts a pair of deep groove ball bearings, and the front ends of the thrust ball bearings are configured so as to ensure the high axial precision and rigidity of the main shaft. The rear support is configured with a pair of angular contact ball bearings in a counter-mounted configuration to improve spindle anti-tipping. The outer shaft gear drives the outer shaft 102 to rotate through a key, and the radial locking and anti-loose lock nut is used for axially fixing the gear, and the gear is arranged close to the front support so as to improve the rigidity of the main shaft.

In order to enable the wire 204 and the base frame 201 to rotate simultaneously, the invention skillfully adopts a shaft sleeve shaft structure, the inner shaft 101 realizes wire rotation, the outer shaft 102 realizes circular cutting movement, the right end of the inner shaft 101 drives the wire 204 to rotate through static connection of the jaw clutch, the outer shaft 102 drives the base frame 201 to rotate through bolt fastening, and if the rotating speed of the inner shaft 101 is faster (or slower) than that of the outer shaft 102, the wire 204 and the base frame 201 generate a relative rotating speed, so that a cutter can be fed (or retracted). When the outer circle of the fixed diameter shaft is cut, the wire 204 and the base frame 202 rotate at the same speed, the relative speed is zero, the cutter 203 is not fed, and the equal diameter cutting is realized; when a stepped shaft, a conical surface or the like is cut, the rotation speed of the wire 204 is faster (or slower) than that of the base frame 202, and a certain rotation speed difference exists between the two, which is represented by cutter feeding (or retracting), so that the variable-diameter cutting is realized.

The circular arc teeth on the sliding block 202 are engaged with the wire threads for transmission, and theoretically, the circular arc teeth are consistent with the plane threads, so that the contact surface is large, and the transmission effect is best. When designing the arc tooth type, because the wire thread is archimedes spiral, the upper arc and the lower arc of the arc tooth need to fit an archimedes spiral, the offset arc is calculated, the radius of the arc outside arc of the arc tooth convex tooth is smaller than the minimum radius of the plane thread, and the radius of the arc inside the convex tooth is larger than the maximum radius of the plane thread, so that the arc tooth can slide at each position of the plane thread.

The frame is provided with a track, the workpiece feeding mechanism is in sliding connection with the track, the workpiece feeding mechanism is a self-centering clamp 6, the workpiece 7 is clamped and then driven by the driving mechanism, and the workpiece 7 is pulled to move rightwards, so that workpiece feeding is realized, and the rigidity of the shaft during processing can be ensured by the mode of the pulling clamp. How the self-centering fixture 6 achieves self-centering is another complete technical solution, which is not described in detail in the present invention.

The cutters 203 are arranged in pairs, the turning positions of each pair of cutters 203 are symmetrical, the cutting stability caused by symmetrical force is fully utilized, the cutters 203 can perform circumferentially symmetrical rotary cutting and simultaneously perform radial feeding cutting, and the workpiece 7 only performs axial feeding movement.

As shown in fig. 2 and 4, a first clamp 4 is arranged on a frame at a certain distance on the right side of the cutting mechanism 2, and a second clamp 5 is arranged at the tail end of the main shaft. The second clamp 5 is arranged between the inner shaft 101 and the cutting mechanism 2 and is fixedly connected with the inner shaft 101; the movable clamping jaw 502 of the second clamp 5 is arranged in the second base 501, the movable clamping jaw 502 is ejected out through a spring, and the four movable clamping jaws 502 are abutted together. The jaw head is provided with a ball 503 which contacts with a workpiece, and the working principle of the mechanism is as follows: the initial state bullet, 504 has precompression volume, makes four clamping jaws close together, and when work piece 7 fed, work piece 7 will be moved in a short distance with movable clamping jaw 502 top, and movable clamping jaw 502 centre gripping work piece 7, and when processing work piece 7, main shaft 1 is rotatory, and No. two anchor clamps 5 follow the rotation too, and the ball 503 on movable clamping jaw 502 enables movable clamping jaw 502 and work piece 7 to carry out rotatory and translational relative motion, and when work piece 7 diameter changes, the spring on the movable clamping jaw 502 can adapt to the work piece diameter, lets movable clamping jaw 502 freely change and presss from both sides tight work piece.

Example 2

As shown in fig. 5, in the embodiment 1, the position of the first clamp 5' is unchanged, and the second clamp 5 is fixed to the front end of the inner shaft. The first clamp 5 'and the second clamp 5 adopt the same flexible clamping structure, the second clamp 5 comprises a second base 501, a movable clamping jaw 502, a ball 503 and a spring 504, and the first clamp 5' comprises a first base 501', a movable clamping jaw 502', a ball 503 'and a spring 504'. The second base 501 is a dog clutch, the second clamp 5 rotates synchronously with the inner shaft 101, and the inner shaft 101 drives the wire 204 to rotate through the static connection of the dog clutch.

The four movable clamping jaws 502 and 502' of the second clamp 5 and the first clamp 5' are uniformly distributed on the circumferences of the second bases 501 and 501', and freely move in the through grooves of the second bases 501 and 501', and the movable clamping jaws 502 and 502' are provided with ear plates to prevent falling from the through grooves. The top cover is embedded on the outer circles of the second base 501 and 501' through screws, and the guide posts are mounted on the top cover through screws. The movable clamping jaws 502 and 502' are provided with blind holes opposite to the guide posts, and the springs 504 and 504' are arranged in the blind holes and penetrate through the guide posts and can freely stretch and retract along with the movement of the movable clamping jaws 502 and 502 '. Each movable jaw 502, 502 'is provided with two balls 503, 503' for reducing friction between the movable jaw 502, 502 'and a workpiece, the balls 503, 503' are arranged on the jaw head, the axial displacement of the movable jaw is limited by a baffle cover, and the radial displacement of the balls is limited by a regular hexagon groove provided with the balls 503, 503 'on the movable jaw 502, 502'. The movable clamping jaws 502, 502' are designed with inclined planes for decomposing the acting force of the workpiece and the clamping jaws so that the workpiece can prop up the clamping jaws. The front and back sides of the second base 501 are respectively provided with rectangular teeth of the jaw clutch, and are arranged between the inner shaft 101 and the wire 204, and the front and back sides are respectively meshed with the wire 204 and the rectangular teeth of the inner shaft 101 to transmit power. Four countersunk holes in base number two 501 are used for axial positioning mounted on the inner shaft 101.

Example 3

As shown in fig. 4, in the centrifugal force-free cutting device provided in this embodiment 3, on the basis of embodiment 1, the second clamp 5 adopts a structure of an elastic clamping jaw and a ball 503, the first clamp 4 adopts an elastic three-jaw chuck structure, rollers (the rollers and the balls act as the same) are arranged on the jaw heads of the movable jaws of the three-jaw chuck, and the first clamp 4 and the second clamp 5 are concentric. The second clamp 5 is matched with the first clamp 4 with the roller 402 and the spring clamping jaw which are arranged on the right side of the cutting mechanism 2 to clamp the workpiece together, so that the processing rigidity of the workpiece can be well enhanced. Because the elastic structure of the clamping jaw can be realized in various modes, for example, on the existing clamping jaw chuck, the clamping jaw is in split type design, one split body is meshed with the wire coil to fix the approximate position, the other split body is connected with the split body through the elastic structure, and the diameter change range of the workpiece is within the deformation range of the elastic structure, therefore, the invention does not need to be illustrated in detail drawings for the structure.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims

1. The utility model provides a no centrifugal force cutting device, sets up in the frame, its characterized in that: the cutting device comprises a main shaft, a cutting mechanism positioned at the front end of the main shaft and a driving mechanism positioned at the rear end of the main shaft and used for driving the main shaft to rotate;

the main shaft comprises an inner shaft and an outer shaft which are in rotary connection and are driven by an inner shaft motor and an outer shaft motor respectively;

the cutting mechanism is driven by the outer shaft to perform circumferential cutting, and the relative rotation speed difference of the inner shaft and the outer shaft is synthesized to realize radial feeding of the cutter;

the cutting mechanism comprises a base frame arranged at the front end of the outer shaft, a sliding block which is connected with the base frame in a sliding way and provided with arc teeth is arranged on the base frame, and a cutter is fixed on the sliding block; the front end of the inner shaft is provided with a wire coil; the arc teeth on the slide block are meshed with the wire coil, and the cutter feeding or retracting is controlled through the rotation speed difference between the outer shaft and the inner shaft;

and a first clamp and a second clamp for clamping the workpiece are respectively arranged at two axial ends of the cutting mechanism.

2. The centrifugal force-free cutting apparatus according to claim 1, wherein: the second clamp is fixed at the front end of the inner shaft and synchronously rotates with the inner shaft, and the second clamp drives the wire coil to rotate through static connection during rotation.

3. The centrifugal force-free cutting apparatus according to claim 2, wherein: the second clamp comprises a second base and a movable clamping jaw elastically propped against the second base, and a ball is arranged on the clamping jaw to be in contact with a workpiece.

4. A centrifugal force-free cutting apparatus according to claim 3, wherein: the first clamp is arranged on the first base and is a three-jaw chuck with elastically telescopic clamping jaws, and the end parts of the clamping jaws are provided with rollers; or the first clamp is arranged on the first base and comprises a movable clamping jaw elastically propped against the first base, and the clamping jaw head is provided with a ball which is in contact with the workpiece.

5. The centrifugal force-free cutting apparatus according to claim 4, wherein: the second base is a jaw clutch, and the front end of the inner shaft drives the wire coil to rotate through static connection of the jaw clutch.

6. The centrifugal force-free cutting apparatus according to claim 1, wherein: the machine frame is also provided with a workpiece feeding mechanism, the workpiece feeding mechanism is a self-centering clamp, and the workpiece is pulled to axially move after being clamped, so that workpiece feeding is realized.

7. The centrifugal force-free cutting apparatus according to claim 1, wherein: the cutters are arranged in pairs, and turning positions of each pair of cutters are symmetrical.

8. The centrifugal force-free cutting apparatus according to claim 1, wherein: the inner shaft and the outer shaft are connected through a sliding bearing, and the outer shaft is supported on the frame through a bearing.