CN114871822A - Centrifugal force-free cutting device - Google Patents

Abstract

The invention provides a centrifugal force-free cutting device, belongs to the technical field of machining, and is mainly used for turning a shaft with weak rigidity, namely a slender shaft. The cutting device is arranged on the rack 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 rotationally connected and respectively driven by an inner shaft motor and an outer shaft motor; the cutting structure is driven by an outer shaft to perform circumferential cutting, and the relative differential motion of the inner shaft and the outer shaft is synthesized to realize the radial feed 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 the 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

A non-centrifugal cutting device

technical field

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

Background technique

In mechanical production and processing, lathes are the most widely used type, accounting for about 50% of the total number of machine tools. Shaft parts are the most common type in lathe processing. Weak stiffness shafts are a common type of shaft parts, such as screw rods, transmission shafts, etc., which are difficult to machine shaft parts. The slender shaft is a typical weak stiffness shaft. The definition of the slender shaft is that the ratio of the length to the diameter of the shaft is greater than 25 (ie, L/D>25). The slender shaft usually has machining processes such as turning outer circle, turning step and turning thread. In the machining of slender shafts, the instability caused by centrifugal force will cause deformation and vibration of the workpiece, reducing the machining accuracy and surface quality of the workpiece, thereby reducing the assembly accuracy and use accuracy of the whole machine.

The traditional slender shaft machining method usually adopts a lathe with one clamp and one top, and the method of cooperating with the center frame or the tool rest for processing. The method of using the steady rest has the disadvantages of increasing the number of processing times, difficulty in controlling the clamping force, the centrifugal force still cannot be ignored, and the processing efficiency is low. However, when using the follower holder to process the slender shaft, the follower holder is easy to contact the outer circle of the shaft too tightly or too loosely, resulting in the phenomenon of knife vibration, and there are defects such as slub and polygonal shapes, which affect the processing quality.

In order to solve the above problems, some scholars have improved the slender shaft technology. On the basis of traditional CNC machining, Liang Manying et al. adopted the interpolation method of linear interpolation and circular interpolation to eliminate the defects of cone and drum shape and improve the processing quality. However, this method is only suitable for CNC machine tools, and the interpolation functions of different brands of CNC machine tools are also different, so the scope of application is narrow. Li Xiaozhou et al. designed a magnetic force and tool holder to solve the problem of insufficient contact with the traditional tool holder. After experiments, the magnetic force and tool holder can effectively reduce the vibration of workpiece machining. However, the magnetic follower can not avoid the problem of low processing efficiency of the follower. Wang Nan et al. deeply studied the method of reverse turning of slender shafts based on the pull-clamp method, and verified this method by simulation analysis method. The results show that the bending deformation and vibration of slender shafts can be effectively reduced. However, this method cannot avoid the influence of the defects of traditional single-tool turning. Hao Chunling outlined the technical points of thread rolling. The thread forming hob is used to press the thread on the workpiece. The thread hob requires high power, slow rotation speed and long contact length, which effectively reduces the radial deformation and vibration of processing. The efficiency is high, but the friction force of the pressed thread is large, the thermal deformation is large, and a large amount of lubricating oil is required to maintain the processing. Dai Haigang et al. studied a double-tool turning method, which uses two turning tools to cut simultaneously on both sides of the tool holder, which effectively improves the machining accuracy and efficiency and reduces unit energy consumption. Huang Xiaodong et al. designed a special machine tool for slender shaft double-headed turning with taper. The machine uses the clamping method to replace the traditional top holding and the follower manipulator instead of the follower holder. The method of turning both sides at the same time improves the efficiency of The machining stiffness and machining efficiency of the slender shaft are improved. The research of Dai Haigang and Huang Xiaodong only improved the traditional machine tool processing method and traditional machine tool, but did not solve the problem of vibration caused by centrifugal force on the workpiece. Wang Peng et al. designed a special machine tool for the processing of variable diameter slender shafts, which can effectively improve the machining accuracy and quality of variable diameter slender shafts. The machine is still not free from the drawbacks of single-tool machining and workpiece rotation. Liu Shunhua outlined the principle of whirlwind milling and its application in thread cutting. Whirlwind milling is a relatively advanced processing method in modern times. The principle of whirling thread milling is to rotate the workpiece at high speed through eccentric inclination of the milling cutter head, and cooperate with the feed control. Shape the threads. The disadvantage of whirlwind milling is that the unidirectional cutting of the milling cutter head will cause the workpiece to be deformed by one-way force. Dai Haigang et al. studied a three-tool turning plan with a difference of 120 degrees in plane roundness, analyzed the force of the plan, and used the ANASYS software to simulate and analyze and concluded that the bending deformation of the turning workpiece in this plan is much smaller than the traditional lathe machining deformation. conclusion. This scheme has only been studied in theory, and has not actually verified the authenticity of the theory. Mao Jiangfeng et al. designed a double-knife cyclone cutter head and centering chuck that can be installed on a CA6140 lathe, which can realize the machining method of tool rotation cutting and workpiece feeding. Double-knife machining reduces machining deformation in principle. Effectively improve the machining accuracy. However, the double-knife cyclone cutter head can only be used for the machining of slender shafts with a single diameter, and the machining is not flexible enough.

In addition, some foreign scholars have also done research on the above-mentioned issues. Wu Mingming et al. used the finite element analysis method to study the turning process of the slender shaft, and the study showed that the reverse turning method can improve the machining accuracy of the slender shaft. In order to reduce the number of trials and errors for selecting the optimal process parameters for machining slender shafts, Milad Azvar et al. established a multi-dimensional analysis model for chatter stability in parallel turning. This method can quickly determine the chatter-free and high-productivity cutting conditions and improve the productivity of slender shafts. and machining accuracy. Tie Ling Wang et al. used Pro/ENGINEER and Pro/MECHANICA software to analyze the influence of different clamping methods on the machining deformation and natural frequency of slender shafts, and obtained a process plan to reduce machining deformation and vibration. Aiming at the problem that any slender shaft diameter error will lead to tool wear and poor machining accuracy, Ding Pengfei et al. established a reliability parameter optimization model considering the diameter error. This model can well improve the reliability of selecting cutting parameters and improve the slender shaft. Precision. Hong Wang et al. conducted a mechanical analysis on the use of reverse turning technology for slender shaft machining, established a mathematical model, and the study showed that the bending deformation and machining error under reverse turning conditions were much smaller than those of normal turning. The above-mentioned researches by Wu Mingming, Milad Azvar, Tie Ling Wang and other scholars are all from the perspective of cutting parameters, using the simulation method to analyze the error, optimize the turning of the slender shaft, improve the machining accuracy is limited, still can not solve the centrifugal force effect. Processing problems caused by the workpiece. Lian Qing Chen et al. studied an error compensation method based on PID controller to compensate the machining error of slender shafts. The experimental results show that this method can improve the machining accuracy of slender shafts. Guo Jianliang used Rayleigh beam theory to numerically simulate the turning process to solve the problem of diameter error caused by dynamic response in the machining of slender shafts, and obtained a method to measure the diameter error caused by vibration of rotating workpieces. The research of Lian Qing Chen, Guo Jianliang, etc. provides solutions in terms of actual error measurement, but does not substantially solve the problem that centrifugal force affects machining, and the improved machining accuracy is also limited. Kai Bo Lu et al. studied the dynamic process of double-spindle turning of slender shafts, analyzed the dynamic response of the rotating workpiece, discussed the influence of cutting parameters on the response of the shaft system and the natural frequency, and finally gave a method to improve the machining accuracy. But this method only stays at the stage of theoretical analysis. Jin Chun Feng et al. studied a machining method for turning trapezoidal threads on slender shafts, expounded the methods and approaches for machining trapezoidal threads on slender shafts, and provided experience for high-precision machining of slender screw rods. But still can not get rid of the defects of traditional processing. Yang Lin et al. studied the machining process of variable-diameter slender shafts, and designed a machine tool using a flexible hydraulic follower and an elastic tailstock, which effectively improved the machining accuracy and machining quality. But the defects of workpiece rotary machining still exist.

In summary, the above research partially solves the defects in the machining of slender shafts, but most of them do not involve multi-tool symmetrical circumferential and radial cutting, as well as cutting processing research of workpiece feed.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention proposes a method that converts the rotation of the workpiece into a symmetrical tool for rotary cutting, and converts the axial feed of the tool into a pulling feed, the workpiece is hardly affected by centrifugal force, and the vibration becomes smaller when machining the workpiece. It is a non-centrifugal cutting device that can avoid the stress on one side of the workpiece, reduce the deformation of the workpiece, and achieve the purpose of improving machining accuracy, machining quality and machining efficiency.

The technical scheme of the present invention is realized as follows:

A non-centrifugal cutting device, which is arranged on a frame, includes a main shaft, a cutting mechanism at the front end of the main shaft, and a driving mechanism at the rear end of the main shaft for driving the main shaft to rotate; the main shaft includes an inner shaft and an outer shaft, the inner shaft and the The outer shaft is rotatably connected and is driven by the inner shaft motor and the outer shaft motor respectively; the cutting structure is driven by the outer shaft to perform circumferential cutting, and the relative rotational speeds of the inner shaft and the outer shaft are combined to realize the radial feed of the tool.

Further, the cutting mechanism includes a base frame arranged at the front end of the outer shaft, the base frame is provided with a slider that is slidably connected with the base frame and has arc teeth, and the cutter is fixed on the slider; the front end of the inner shaft is provided with a coil wire. ; The arc teeth on the slider mesh with the coil wire, and the tool feed or retract is controlled synthetically through the speed difference between the outer shaft and the inner shaft.

Further, the two axial ends of the cutting mechanism are respectively provided with a No. 1 clamp and a No. 2 clamp for clamping the workpiece.

Further, the No. 2 clamp is fixed at the front end of the inner shaft, and rotates synchronously with the inner shaft. When rotating, the No. 2 clamp drives the coil wire to rotate through a static connection.

Further, the No. 2 clamp includes a No. 2 base, and a movable clamping claw that is elastically pressed against the base, and a ball is provided on the head of the clamping claw to contact the workpiece.

Further, the No. 1 clamp is arranged on the No. 1 base, and is a three-jaw chuck with elastically retractable jaws, and the end of the jaw is provided with a roller; or, alternatively, the No. 1 clamp is arranged on a No. 1 chuck. The No. 1 base includes a movable gripper that is elastically pressed against the No. 1 base, and a ball is provided on the gripper head to contact the workpiece.

Further, the No. 2 base is a claw clutch, and the front end of the inner shaft drives the coil wire to rotate through the static connection of the claw clutch.

Further, the frame is also provided with a workpiece feeding structure, and the workpiece feeding mechanism is a self-centering fixture, which clamps the workpiece and pulls the workpiece to move in the axial direction to realize the workpiece feeding.

Further, the tools are arranged in pairs, and the 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 the bearing.

The present invention has the following beneficial effects:

1. The cutting mechanism is detachable and installed on the spindle head, and the cutting mechanism can rotate with the spindle to cut the workpiece. The inner shaft and the outer shaft are driven to rotate by their respective drive motors and deceleration mechanisms. When cutting the outer circle of the fixed diameter shaft, the coil wire and the base frame rotate at the same speed at the same time, the relative speed is zero, the tool does not feed, and the equal diameter cutting is realized; When cutting stepped shafts, tapered surfaces, etc., the speed of the coil wire is faster (or slower) than the speed of the base frame, and there is a certain speed difference between them, thereby realizing variable diameter cutting. When the speed difference between the inner shaft and the outer shaft occurs, the synthesis mechanism (coil wire and slider with arc teeth) synthesizes the spindle motion and the radial feed motion, which is reflected as the tool feed (or retract).

2. During the cutting process, the symmetrical force of the tool is offset by even numbers, and the machining process ensures the stable force of the workpiece and avoids deformation.

3. Fix the No. 1 fixture at a distance on the right side of the cutting mechanism, and install the No. 2 fixture at the end of the spindle or the left side of the cutting mechanism. It does not affect the axial feed of the workpiece, and overcomes the obstacles caused by the gripper jaws to the workpiece feed caused by the uneven surface of the workpiece when the workpiece is axially fed.

4. The axial feeding mechanism of the workpiece adopts the method of pulling and clamping, so that the workpiece is fed from left to right to ensure the rigidity of the shaft during processing.

Description of drawings

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;

3 is a schematic diagram of the main shaft mechanism of the present invention;

4 is a structural cross-sectional view of Embodiment 1 of the present invention;

5 is a structural cross-sectional view of Embodiment 2 of the present invention;

Fig. 6 is the sectional view of No. 2 clamp of the present invention;

FIG. 7 is a perspective view of the No. 2 clamp of the present invention.

In the picture: 1-spindle, 101-inner shaft, 102-outer shaft, 2-cutting mechanism, 201-base frame, 202-slider, 203-tool, 204-coil wire, 3-drive mechanism, 301-inner shaft motor, 302-External shaft motor, 4-No.1 clamp, 401-Gripper, 402-Roller, 5-No.2 clamp, 501-No.2 base, 502-Active jaw, 503-Ball, 504-Spring, 5' - No. 1 clamp, 501'- No. 1 base, 502'- movable jaw, 503'- ball, 504'- spring, 6- self-centering clamp, 7- workpiece.

Detailed ways

The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

1-4, a non-centrifugal cutting device is provided on a frame, and is mainly composed of a main shaft 1, a cutting mechanism 2 located at the front end of the main shaft, and a driving mechanism 3 located at the rear end of the main shaft 1 for driving the main shaft 1 to rotate; The main shaft 1 includes an inner shaft 101 and an outer shaft 102, the outer shaft 102 is sleeved outside the inner shaft 101, and the inner and outer shafts can rotate mutually. Lubricated sliding bearing connections can also be used for bearing bush connections. Because the type of workpiece to be machined is a slender shaft, the feed rate and cutting force are small, and the cutting force is also small, so the bearing combination is a speed type combination, and a pair of deep groove ball bearings and thrust ball bearings are selected for the front support of the outer shaft 102 Combination, double deep groove ball bearings improve the rigidity of the front support, the front support configuration of the thrust ball bearing can reduce the influence of thermal deformation of the main shaft; a pair of angular contact ball bearing combination is selected for the rear support, and the reverse installation method is adopted to improve the anti-overturning ability of the main shaft. .

The inner shaft 101 and the outer shaft 102 are driven by the inner shaft motor 301 and the outer shaft motor 302 respectively; the inner shaft and the outer shaft are respectively connected with the inner and outer shaft motors through their respective speed change groups, because the inner shaft 101 needs to cooperate with the electronic control system for stepless adjustment Therefore, the servo motor is selected as the power source, which can precisely control the speed of the inner shaft 101, so as to realize the cutting feed through the speed difference between the inner and outer shafts. The internal and external main shaft transmission scheme adopts ordinary cylindrical spur gear transmission, which is simple and reliable, and can ensure the rotation accuracy. As shown in Figures 3 and 4, the outer shaft gear is placed close to the front support to reduce the force and deformation of the outer shaft; due to structural limitations, the gear of the inner shaft 101 can only be placed at the tail end, in order to strengthen the tail end of the inner shaft 101 To increase the rigidity of the end, add deep groove ball bearings on the left and right of the gear as a support for the rear end of the inner shaft 101. As shown in FIG. 3 , the driving mechanisms are arranged on the left and right sides of the main shaft 1 to prevent the main shaft 1 from being bent and deformed to one side under a unilateral force.

The cutting mechanism 2 is fixed on the front end of the outer shaft 102, and includes a base frame 201. The base frame 201 is provided with a sliding block 202 that is slidably connected to the base frame 201 and has arc teeth. The tool 203 is fixed on the sliding block 202. 102 drives to perform circumferential cutting; the front end of the inner shaft 101 is provided with a coil wire 204; the arc teeth on the slider 202 mesh with the coil wire 204, and through the speed difference between the outer shaft 102 and the inner shaft 101, the synthetic control tool 203 feeds The advantage of using the coil wire is that the processing technology of the coil wire is relatively mature, the feed amount is accurately determined by the pitch, and the feed movement speed of the coil wire drive is constant speed, which can cut evenly, and the coil wire can withstand large The radial cutting reaction force.

The outer circle of the solid lubricated sliding bearing bush is in interference fit with the inner hole of the outer shaft 102, and the outer circle of the inner shaft 101 is in transition fit with the inner circle of the bearing pad with solid lubricant. The inner shaft 101 and the outer shaft 102 can rotate relative to each other. The gears and the gears of the outer shaft 102 transmit power, respectively driving the coil wire 204 and the base frame 201 to realize differential rotation. The inner shaft gear is placed at the rear of the inner shaft 101, and the inner shaft 101 is driven to rotate by a key, and deep groove ball bearings and deep groove ball bearings are arranged before and after the gear to increase the stiffness of the shaft near the tail gear. A space is reserved at the rear of the inner shaft 101 to place the oil pan to deliver the lubricating oil to the lubrication system. The outer shaft 102 is supported by a support method in which one end is fixed and one end is free. The front support is fixed by a sleeve cup, and the rear support is freely placed on the box. Due to the high speed requirement for machining the slender shaft, a pair of deep groove ball bearings are used for the front support, and the front end of the thrust ball bearing is arranged to ensure the high axial precision and rigidity of the main shaft. The rear support adopts a pair of angular contact ball bearings in reverse configuration to improve the anti-overturning performance of the main shaft. The outer shaft gear drives the outer shaft 102 to rotate through a key, and the gear is axially fixed by a radial locking and anti-loosening lock nut. The gear is arranged close to the front support to improve the rigidity of the main shaft.

In order to make the coil wire 204 and the base frame 201 rotate at the same time, the present invention cleverly adopts the structure of the shaft sleeve. The connection drives the coil wire 204 to rotate, and the outer shaft 102 drives the base frame 201 to rotate through bolt tightening. If the inner shaft 101 rotates faster (or slower) than the outer shaft 102, the coil wire 204 and the base frame 201 will generate a relative rotation speed, To advance (or retract) the tool. When cutting the outer circle of the fixed-diameter shaft, the coil wire 204 and the base frame 202 rotate at the same speed at the same time, the relative speed is zero, and the cutter 203 does not feed, so as to realize equal-diameter cutting; when cutting the stepped shaft, the tapered surface, etc., the coil wire 204 The rotational speed of the tool is faster (or slower) than the rotational speed of the base frame 202, and there is a certain rotational speed difference between them, which is reflected in the tool advancing (or retracting), thereby realizing variable diameter cutting.

The arc teeth on the slider 202 are connected with the coil thread for transmission. Theoretically, the arc tooth profile should be consistent with the plane thread, the contact surface is large, and the transmission effect is the best, but if the profile is consistent with the plane thread, due to the different geometric relationship , which will cause the arc teeth to be unable to slide on the concave teeth of the flat thread of the coil wire. When designing the arc tooth profile, since the coil thread is an Archimedes spiral, the upper and lower arcs of the arc tooth need to fit an Archimedes spiral, and the offset arc is calculated, and the arc tooth is convex. The radius of the outer arc should be smaller than the minimum radius of the plane thread, and the radius of the inner arc of the convex tooth should be greater than the maximum radius of the plane thread, so that the arc tooth can slide at each position of the plane thread.

A track is set on the frame, and the workpiece feeding mechanism is slidably connected on the track. The workpiece feeding mechanism is a self-centering fixture 6. After clamping the workpiece 7, it is driven by a driving mechanism to pull the workpiece 7 to move to the right, thereby realizing workpiece feeding. The way of pulling the clamp can ensure the rigidity of the shaft during machining. How the self-centering fixture 6 realizes self-centering is another complete technical solution, which will not be described in detail in the present invention.

The cutters 203 are arranged in pairs, and the turning positions of each pair of cutters 203 are symmetrical, making full use of the cutting stability brought about by the symmetrical force. Only the axial feed movement is performed.

As shown in Figures 2 and 4, a No. 1 clamp 4 is installed on the frame at a distance from the right side of the cutting mechanism 2, and a No. 2 clamp 5 is installed at the tail end of the spindle. The second clamp 5 is installed between the inner shaft 101 and the cutting mechanism 2, and is fixedly connected with the inner shaft 101; the movable jaw 502 of the second clamp 5 is arranged in the second base 501, and the movable jaw 502 is pushed out by a spring , the four movable jaws 502 are close together. The gripper head is equipped with balls 503 that are in contact with the workpiece. The working principle of the mechanism: the initial state is elastic, and the 504 has a pre-compression amount, so that the four gripping jaws are close together. When the workpiece 7 is fed, the workpiece 7 will move the gripping jaws. 502 is pushed open, and the movable jaw 502 clamps the workpiece 7. When the workpiece 7 is processed, the spindle 1 rotates, and the second fixture 5 also rotates. The ball 503 on the movable jaw 502 can make the movable jaw 502 and the workpiece 7 move The relative movement of rotation and translation, when the diameter of the workpiece 7 changes, the spring on the movable jaw 502 can adapt to the diameter of the workpiece, allowing the movable jaw 502 to freely change to clamp the workpiece.

Example 2

As shown in FIG. 5 , on the basis of Embodiment 1, the position of the No. 1 clamp 5 ′ in this embodiment remains unchanged, and the No. 2 clamp 5 is fixed to the front end of the inner shaft. No. 1 clamp 5' and No. 2 clamp 5 adopt the same flexible clamping structure, No. 2 clamp 5 includes No. 2 base 501, movable jaws 502, balls 503 and spring 504, No. 1 clamp 5' includes No. 1 base 501', movable jaw 502', ball 503' and spring 504'. The No. 2 base 501 is a jaw clutch, the No. 2 clamp 5 rotates synchronously with the inner shaft 101, and the inner shaft 101 drives the coil wire 204 to rotate through the static connection of the jaw clutch.

The four movable jaws 502, 502' of the No. 2 fixture 5 and No. 1 fixture 5' are evenly distributed on the circumference of the No. 2 base 501, 501', and move freely in the through grooves of the No. 2 base 501, 501', The movable jaws 502 and 502' are provided with ear plates to prevent them from falling off from the through grooves. The top cover is embedded on the outer circle of No. 2 bases 501 and 501' by screws, and the guide posts are installed on the top cover by screws. The movable jaws 502, 502' have blind holes facing the guide post, and the springs 504, 504' are installed in the blind holes and pass through the guide post, and can freely expand and contract with the movement of the movable jaws 502, 502'. Each movable jaw 502, 502' is installed with two balls 503, 503' to reduce the friction between the movable jaw 502, 502' and the workpiece. The balls 503, 503' are installed on the jaw head, and pass through the The cover limits its axial displacement, and the regular hexagonal grooves on which the balls 503, 503' are mounted on the movable jaws 502, 502' limit the radial displacement of the balls. The movable clamping jaws 502 and 502' are designed with inclined surfaces, which are used to decompose the force between the workpiece and the clamping jaws, so that the workpiece can push the clamping jaws away. The No. 2 base 501 has rectangular teeth on the front and back sides of the claw clutch, which are installed between the inner shaft 101 and the coil wire 204 . The four countersunk holes on the No. 2 base 501 are used for axial positioning on the inner shaft 101 .

Example 3

As shown in FIG. 4 , a non-centrifugal cutting device provided in the third embodiment, on the basis of the first embodiment, the No. 2 clamp 5 adopts the structure of elastic clamping jaws and balls 503, and the No. 1 clamp 4 adopts the elastic three jaws In the chuck structure, the claw head of the movable claw of the three-jaw chuck is provided with a roller (the roller and the ball have the same function), and the No. 1 fixture 4 and the No. 2 fixture 5 are concentric. The No. 2 fixture 5 cooperates with the No. 1 fixture 4 with the roller 402 installed on the right side of the cutting mechanism 2 and the No. 1 fixture 4 with spring clamping jaws to clamp the workpiece, which can well enhance the machining rigidity of the workpiece. Because the elastic structure of the clamping jaw can be realized in various ways, for example, on the existing clamping jaw chuck, the clamping jaw is designed in two parts, one part is engaged with the coil wire to fix the approximate position, and the other part is elastically The structure is connected to the aforementioned separate body, and the diameter variation range of the workpiece can be within the deformation range of the elastic structure. Therefore, the present invention does not provide detailed drawings for this structure.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. The utility model provides a centrifugal force free cutting device, sets up in the frame, its characterized in that: the cutting machine 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 rotationally connected and respectively driven by an inner shaft motor and an outer shaft motor;

the cutting structure is driven by an outer shaft to carry out 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.

2. The centrifugal-force-free cutting apparatus according to claim 1, wherein: the cutting mechanism comprises a base frame arranged at the front end of an outer shaft, a sliding block which is connected with the base frame in a sliding mode 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 sliding block are meshed with the wire coil, and the feeding or retracting of the cutter is controlled by the synthesis through the rotating speed difference between the outer shaft and the inner shaft.

3. The centrifugal-force-free cutting apparatus according to claim 2, wherein: and a first clamp and a second clamp for clamping a workpiece are respectively arranged at two axial ends of the cutting mechanism.

4. The centrifugal-force-free cutting apparatus according to claim 3, wherein: and the second fixture is fixed at the front end of the inner shaft and synchronously rotates with the inner shaft, and the second fixture drives the wire coiling to rotate through static connection during rotation.

5. The centrifugal-force-free cutting apparatus according to claim 4, wherein: the second clamp comprises a second base and a movable clamping jaw elastically and tightly propped against the second base, and a ball is arranged on the clamping jaw head and is in contact with a workpiece.

6. The centrifugal-force-free cutting apparatus according to claim 5, wherein: the first clamp is arranged on the first base and is a three-jaw chuck with clamping jaws capable of elastically stretching, 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 and tightly propped against the first base, and a ball is arranged on the clamping jaw head and is contacted with the workpiece.

7. The centrifugal-force-free cutting apparatus according to claim 5, 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.

8. 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 clamped and pulled to move along the axial direction, so that the workpiece feeding is realized.

9. The centrifugal-force-free cutting apparatus according to claim 2, wherein: the cutters are arranged in pairs, and the turning positions of each pair of cutters are symmetrical.

10. 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.

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