A double vertical clamping structure for double worm gear flying cutters

Abstract

The present invention relates to a double vertical clamping structure of a double worm gear flying cutter, wherein a center hole concentric with the cutter rod is provided at the passive end of the cutter rod, two parallel connecting through holes for installing and tightening the flying cutter are provided radially, and are connected with the center hole, and the center distance thereof is the axial pitch of a working worm, and planes are provided at both ends of the connecting through hole, and a tightening screw is provided on the plane on the same side, and is connected with a screw hole on a straight handle of the flying cutter, and a positioning clamping mechanism is provided in the center hole, and a force-applying component, a plurality of round balls, a positioning push rod, a flying cutter, an elastic push rod, etc. are provided in sequence from the end face of the passive end, and under the action of the tightening screw and the force-applying component, the opposite end oblique end face of the positioning push rod slides to the oblique flat plane of the straight handle of the flying cutter to form a close surface contact, and the two flying cutters are fastened in the corresponding connecting through holes, so that the cutting edge part of the flying cutter is in the same position as the working worm. This positioning and double vertical clamping technical scheme is suitable for rolling cutting of multi-head worm wheels with large cutting force, modulus and lead angle.

Description

Technical Field

[0001] The invention relates to a double vertical clamping structure of a double worm gear flying cutter, which is mainly used for rolling cutting of cylindrical worm driven multi-head worm gears with small working worm diameter, high precision and large cutting force. Background Art

[0002] When rolling a worm gear, the basic geometric parameters of the worm gear hob must generally be the same as those of the working worm (i.e., the worm meshing with the worm gear being rolled). Therefore, the worm gear hob is a highly targeted special tool with low utilization and high price. It has a long production cycle and is not economical to use. In addition, it is difficult to manufacture multi-head worm gear hobs. It is very uneconomical to manufacture worm gear hobs in single-piece small batch production. In this case, a fly cutter can be used to process the worm gear. The fly cutter is essentially a worm gear hob with no less than one tooth. Its tooth cutting principle is the same as that of a tangential worm gear hob. The main advantages and disadvantages of the fly cutter are simple structure and easy manufacturing, low cost and production efficiency. However, if the fly cutter and the tool bar are properly designed, accurately manufactured, and used correctly, the precision of the worm gear processed is not lower than that of the worm gear hob. This is also one of the main reasons why fly cutters are often used to process worm gears. Regardless of whether the number of worm gear teeth and the number of thread heads of the working worm are integer multiples or whether there is a greatest common factor between them, in order to reduce manual separation (error) and improve gear cutting efficiency and tool bar rigidity, the axial center distance of the flying cutter along the tool bar is generally taken as the axial pitch of a working worm. Due to its small structural size, it is easy for the flying cutter to interfere with the clamping and positioning parts and weaken the strength of the tool bar here, and even cause difficulties in manufacturing the tool bar; thus, it is necessary to use the axial pitch of more than one working worm, which increases the tool bar length and tangential feed length. In this way, the distance between the tool bar seats supported by the active and passive ends of the tool bar is relatively long, the rigidity of the tool bar is weakened, and the tangential feed time is prolonged, affecting the rigidity and strength of the tool bar and the gear cutting efficiency, and even the tooth surface quality. It is also limited by the limit of the tangential feed stroke of the machine tool, making it difficult or impossible to implement. Figure 1 The figure shows the clamping structure for processing medium and small module worm gear cutters; the straight round shank of the cutter is installed in the round hole of the tool bar 1, and the nuts 3 and 4 are tightened to make the round sleeve 2 move axially along the outer cylindrical surface of the tool bar 1. The concave arc groove set along the center line of the round sleeve 2 hole and along its axial direction is clamped along the straight round shank of the cutter. Because the round sleeve 2 needs to move axially along the outer cylindrical surface of the tool bar 1, the diameter of the tool bar 1 becomes smaller, affecting the strength; this tool bar structure is simple and easy to adjust, but the clamping reliability is slightly poor, and the concave arc groove has higher requirements. Obviously, this structure is not suitable for positioning and clamping of double worm gear cutters and working worms with smaller diameters. There are two clamping structures for processing large module worm gear cutters, such as Figure 2 and 3As shown, tightening the nut causes the round tie rod with the screw to move axially within the circular hole. The concave arc groove or beveled surface provided on the cylindrical portion of the tie rod locks the round straight shank of the fly cutter or the beveled surface of the round straight shank of the fly cutter, respectively. This clamping structure has a strong clamping force and the fly cutter is not easy to loosen. However, the circular holes for mounting the round tie rod and the fly cutter are arranged perpendicularly and cross-through along the radial direction of the tool arbor in these two clamping structures, which weakens the tool arbor's strength and rigidity. This vertically staggered hole structure is suitable for situations where the working worm (tool arbor) diameter and the adjacent center distance of the fly cutters are large. Therefore, it limits the use of multiple fly cutters. To avoid the difficulties in manufacturing the tool arbor for multiple fly cutters and adjusting the fly cutters, a single fly cutter has to be used instead, which reduces productivity. Because the number of flying cutters is very small and the cutting volume is large, the cutting edge is easy to wear, and the local wear is fast, which increases the cutting resistance. Because the flying cutter is fed tangentially when rolling the worm gear, when the flying cutter rolls from the cutting end to the cutting end, the cutting edge of the flying cutter cuts from one side to both sides and then to the other side. The flying cutter generates a large periodic alternating torque along its axis. There is a small gap between the round straight shank of the flying cutter and the round hole of the tool rod, and is affected by the stiffness of the tool rod and the support end and the gap between rotating parts such as bearings. The poor dynamic stiffness is easy to cause vibration, which causes the flying cutter to loosen, fall off, or even damage the worm gear under the action of the alternating cutting impact force; especially the working worm has a small diameter, a large module and a cutting force, and especially the cutting conditions of the cutting edges on both sides of the flying cutter with a large lead angle are quite different, and the above-mentioned clamping structures are difficult to cope with. Summary of the Invention

[0003] The purpose of the present invention is to provide a double worm gear flying cutter with a center distance equal to the axial tooth pitch of a working worm, and an online radial precise adjustment and positioning and a double vertical clamping structure to improve the worm gear precision and productivity and the durability of the flying cutter; it is suitable for the firm clamping of double worm gear flying cutters with small working worm diameters, large modules and cutting forces, especially for the rolling cutting of multi-head worm gears that require manual separation and high precision.

[0004] The technical solution of the present invention is: it includes a tool rod, the tool rod consists of an active end with a tapered shank and an elongated passive end, the passive end is provided with a center hole facing the active end and concentric with the rotation center line of the tool rod, and two parallel connecting through holes for installing and tightening the flying cutter are radially provided along the rotation center line of the tool rod in the middle of the tool rod, the center distance between the connecting through holes is the axial tooth pitch πm of a working worm, and the two straight-view ends of the connecting through holes are provided with planes, wherein the planes on the same side of the rotation center line of the tool rod are provided with tightening screws, and are connected to the screw holes provided on the axis line of the straight shank of the flying cutter, the center line of the connecting through hole is perpendicular and passes through the rotation center line of the tool rod, and is connected with the center hole, a positioning clamping mechanism is provided in the center hole, and a force-applying component, a plurality of balls, a first fixed component are provided inwardly from the end face of the passive end. The positioning push rod, the first flying cutter, the elastic push rod and pass through the hole on the oblique flat plane of the first flying cutter straight handle, the second positioning push rod and the second flying cutter, and the cylindrical end of the elastic push rod is inserted into the concentric positioning blind hole at one end of the oblique end surface of the first positioning push rod. The angle between the oblique flat plane of the flying cutter straight handle and the axis of the flying cutter straight handle is an acute angle θ or 0°. Under the joint action of the force generated by the tightening screw and the force-applying component, the opposite end oblique end surfaces of the first positioning push rod and the second positioning push rod slide simultaneously to the oblique flat plane of the flying cutter straight handle to form a close surface contact, and the two flying cutters are fastened in the corresponding connecting through holes. The cutting edge parts of the two flying cutter heads are in the same position as the working worm, and are extended in the same direction as the tool rod and the zero rake angle rake surface of the flying cutter faces the rotation direction when the flying cutter is working.

[0005] By adopting this technical solution, the center distance of the double worm gear cutters axially arranged on the two adjacent threads is minimized, and thus the elastic push rod is shortest, which makes it easier to position and clamp the double cutters, and the tangential stroke of the cutters is short, resulting in the highest productivity. In addition, a positioning and clamping mechanism is provided in the concentric center hole of the cutter bar, so that the cutter bar length can be set to the shortest and the diameter to the largest. From the perspective of material mechanics, the center hole has the least effect on the strength and stiffness of the cutter bar, and at this time the strength and stiffness of the cutter bar are maximized, which is very important for worm gears with smaller working worm diameters. Since there is an additional cutter, manual separation and rough tooth cutting can be reduced to improve productivity and tooth surface quality as well as the durability of the cutter between two regrindings. When sharpening the cutter during the precision cutting process, step differences will appear on the tooth surface, and tooth thickness differences may also appear for multi-head worm gears. Therefore, the durability of the cutter between two regrindings is extremely important, which is especially critical for multi-head, large-module, high-number of teeth, and hard precision worm gears. At the same time, according to the working conditions, it is also possible to set up fly cutter groups with different cutting performances (such as coarse and fine) and cutting methods (radial, constant or variable tangential feed) and tooth shapes, so as to give full play to their respective advantages, improve productivity and tooth cutting efficiency, and improve the tooth shape accuracy and productivity of fly cutter rolling worm gears on the basis of existing technologies.

[0006] Since the positioning clamping mechanism is arranged in the center hole and does not take up space, the structure is simple and compact, and the ball is used as the force transmission medium, it is flexible in operation and has less rolling friction loss, so the first positioning push rod is very short, which is convenient for it to move and rotate more freely in the center hole. The closed center hole can store lubricant, which is not easy to lose and can be prevented from being contaminated, making the positioning clamping mechanism more flexible in movement and rust-proof, reducing maintenance. The plane provided in the connecting through hole is combined with the open washer, and online measurement is carried out with the help of measuring instruments, which facilitates the precise radial positioning of the flying cutter on the tool rod and prevents it from moving toward the center of the tool rod after being subjected to cutting force. The setting of the tightening screw adds a vertical clamping force, making the positioning clamping self-locking more reliable and suitable for strong cutting. Under the combined force of the tensioning screw and the force-applying member, the opposing oblique end surfaces of the positioning push rod slide onto the obliquely cut flat surface of the fly cutter's straight shank, forming close surface contact. The two fly cutters are secured within corresponding connecting through-holes. The cutting edges of the two fly cutter heads are located at the same position as the working worm, extending out of the shank in the same direction, and the zero-rake angle rake faces of the fly cutters face the direction of rotation during operation. This creates conditions for fly cutter processing of integral shank worm gear hobs, resolving the bottleneck of manufacturing multi-start worm gear hobs with smaller working worm diameters. The provision of a tensioning screw and a split washer prevents the fly cutter from retreating, making it suitable for roughing with large cutting depths and feed rates, and particularly for fine cutting with small tangential feed rates. This conforms to the principle that fly cutters can artificially improve tooth profile accuracy, significantly improving productivity, particularly for multi-start, large-module, and small-tooth worm gears. Therefore, with proper design of the fly cutter and shank, and the creation of conditions for proper use and maintenance, the precision of the worm gear machined is comparable to that of a worm gear hob, while also achieving higher productivity.

[0007] The length of the tool cutting path during rolling is L P (High-speed steel) or number of load cycles N P (hard alloy), which has a great impact on the life of the tool, so the technical solution of large cutting depth and large tangential cutting amount is adopted to reduce L P and N P The impact on the durability of the fly cutter can improve productivity and tooth surface quality as well as the durability of the fly cutter between two regrindings. Therefore, optimizing the cutting amount is one of the conditions for the correct use of the fly cutter.

[0008] When the number of worm gear teeth and the number of thread heads of the working worm are integer multiples or there is a greatest common factor between them, if manual head separation is not performed, the number of flying cutters (groups) on consecutive adjacent heads shall not be less than the integer multiple or the greatest common factor, and there shall be no less than one flying cutter on each head. In this way, all the tooth grooves of the worm gear can be cut out in one pass. Otherwise, manual head separation is required. The use of double worm gear flying cutters can reduce or eliminate the need for manual head separation, reduce manual head separation errors, and improve productivity.

[0009] When the number of worm gear teeth and the number of thread heads of the working worm are not integer multiples or there is no greatest common factor between them, automatic head separation is used, that is, one fly cutter can cut out all the tooth grooves of the worm gear in one pass; when one of the fly cutters is only used as an "invalid enveloping tooth", the cutting edges of the fly cutter are provided with chip grooves or corrugated edges (hereinafter referred to as edge shapes), or the top height of the fly cutter teeth is slightly increased, so that the top edge of the fly cutter of the "effective enveloping tooth" (with cutting and enveloping functions) does not participate in the cutting, thereby changing the cutting pattern and improving the cutting conditions, especially the technical solution of slightly increasing the top height of the tooth of a fly cutter and the edge shape. This is particularly important for fly cutters with very few teeth, and can very effectively improve the cutting conditions and local wear of the "effective enveloping tooth" fly cutter. The use of technical solutions such as chip grooves can achieve large cutting depth and large feed rate rolling, which greatly improves Gear cutting efficiency, productivity and fly cutter durability. Under the condition of the same tangential feed rate, the final enveloping effect (precision) of the worm gear tooth surface remains unchanged, turning the disadvantage of "ineffective enveloping cutter teeth" with only cutting function but no enveloping function into an advantage, thereby dividing wide thin chips into narrow and thick chips, eliminating the most unfavorable cutting conditions, П and Γ-shaped chips, reducing chip deformation, reducing cutting force and chatter, and facilitating chip removal and heat dissipation without chip entanglement, reducing the friction of chips on the front face of the fly cutter, reducing power consumption, cutting smoothly, and chips forming debris in a controlled manner without damaging the processed tooth surface. The cutting load peak is decomposed and reduced, making the fly cutter wear more evenly, increasing the service life of the fly cutter, and further improving the durability of the fly cutter between two regrindings. It is suitable for efficient cutting of rough tooth grooves, and optimizes the edge shape structure and fly cutter combination of the fly cutter. When the number of worm gear teeth and the number of worm thread starts are integer multiples or have a greatest common factor, a fly cutter can be equipped with a chip splitter to improve cutting conditions, but this requires more manual splitting. Therefore, the use of a chip splitter or a corrugated edge is one of the requirements for proper fly cutter design and use, creating the conditions for optimizing high-efficiency and powerful cutting with large cutting loads.

[0010] The fundamental difference between the flying cutter rolling (tangential feed) and the radial feed method in terms of cutting amount (force) is that the flying cutter is a tangential cutter formed by continuously divided teeth, so the flying cutter always cuts teeth one by one from the side of the tooth blank turning end. The flying cutter (or the flying cutter cutting end) also bears the additional cutting amount that should be removed by the edge of the other teeth of the radial worm gear hob, which increases the cutting load of the flying cutter. At the same time, the number of flying cutters is very small, the cutting amount itself is large, the cutting resistance is also large, the cutting load peak is extremely large, and the flying cutter wears unevenly and wears quickly, which causes the flying cutter to fail prematurely, seriously restricting the improvement of productivity. The flying cutter has a simple structure and small geometric size, and is easy to manufacture and sharpen. High-precision, high-performance, and high-hardness flying cutters are easier to obtain than hobs. By optimizing and improving the blade shape, cutting angles, structural form, material, etc. of the rough cutting flying cutter, the flying cutter cutting conditions (environment) are improved, and the existing deficiencies are overcome. Optimizing and improving the rough cutting flying cutter (group) is the key to improving productivity.

[0011] Regardless of whether the number of worm gear teeth and the number of thread heads of the working worm are integer multiples or whether there is a greatest common factor between them, the double worm gear fly cutters can also be divided into two groups, rough cutting and fine cutting, to improve productivity (tooth cutting efficiency) and tooth profile accuracy (contact spots). When using the rough cutting fly cutter group, the rolling and adjustment are performed according to the radial feed method, that is, the machine tool only has tooth-splitting movement, and no additional developing (tangential) movement, so the tangential feed movement (transmission chain) is reduced, and the rigidity of the machine tool-tool process system is improved. Combined with the maximum strength and rigidity of the tool rod of the present invention, the fly cutter can be accurately positioned and firmly clamped on the tool rod and never retreat, as well as the chip groove technology, which is suitable for strong and efficient cutting of rough cutting tooth grooves to overcome the inherent deficiency of low tooth cutting efficiency due to a small number of fly cutters, especially radial feed to make up for the tangential feed cutting method. The radial feed method has the inherent disadvantage of a longer entry length and thus a lower productivity than the radial feed method. At this time, the radial feed method has the advantage of the cutting edges on both sides of the hob teeth participating in the cutting, the cutting allowance is more uniform, and the subsequent tooth cutting conditions are improved. The design principle of the rough cutting fly cutter group is: the cutting load of the first cutting fly cutter should not be too heavy and the tooth top height of the later cutting fly cutter should be slightly higher than that of the fine cutting fly cutter. The cutting edges (such as chip grooves) and cutting angles (such as specially sharpened front cutting edges) are optimized, and the cutting load of the double fly cutters with different tooth heights, tooth profile angles, and tooth thicknesses is relatively uniform. When rough cutting, the center line between the double worm gear fly cutters passes through the center of the tooth blank. After the rough cutting is completed, the motion relationship between the machine tool and the tool is kept unchanged, the fly cutter is moved tangentially and the fine cutting fly cutter is replaced. The connection starts the expansion motion and the rolling cut is carried out with a small tangential feed. This technical solution fully leverages the advantages of the blade and tooth profiles of fly cutters with different feed methods and cutting performance, as well as the optimized cutting edges and process system. This fully leverages the advantages of the fly cutter, balancing or reducing the peak cutting load, effectively improving the cutting conditions for rough and fine tooth cutting, and further increasing productivity and the durability of the fly cutter between regrindings, thereby improving tooth profile accuracy and productivity. This improves the tooth profile accuracy and productivity of fly cutter hobbing worm gears compared to existing technologies. By fully leveraging the advantages of the blade and tooth profiles of fly cutters with different feed methods and cutting performance, as well as the optimized cutting edges and process system, this process design creates conditions for optimizing cutting parameters, which is one of the conditions for correct fly cutter use.

[0012] According to the working conditions (such as hard tooth surface), the double flying cutters of the fine cutting fly cutter group can adopt a one coarse and one fine tool matching scheme, that is, the double flying cutters are used to alternately cut on the same tooth surface by using a split head, which optimizes the fine cutting process scheme to improve the durability of the fine cutting fly cutter between two re-grindings. The effective cutting depth of the chip groove or the concave part of the wave edge matches the feed rate and the trajectory of the fly cutter cutting, which is more conducive to improving the division into narrower and thicker chips and balancing or reducing the cutting load peak, improving the effect of chip removal, chip breaking and efficient gear cutting, and facilitating rolling cutting with large cutting depth and large feed rate, creating conditions for optimizing cutting parameters, reducing the number of feeds and improving gear cutting efficiency and the durability of the fly cutter. Therefore, the optimized process design scheme is one of the conditions for the correct use of the fly cutter.

[0013] Because fly cutter hobbing does not suffer from the same theoretical errors as hobbing, and because fly cutters are simple structures and mostly single-tooth, they are easy to manufacture and sharpen, at a low cost. High-precision, high-performance, and high-hardness fly cutters are more readily available than hobs. The number of broken line segments encompassing the tooth profile can be freely controlled during the cutting process, adjusting the tangential feed rate. This is inversely proportional to the tangential feed rate and is independent of the number of worm gear teeth. Fly cutters lack the chip flutes of hobs, allowing chips to curl freely without the chip blockage caused by insufficient chip space. Frictional work and frictional deformation during chip flow are minimized, reducing plastic deformation and cutting forces during cutting. Chips form and flow smoothly along the rake face, falling under their own weight. This improves heat dissipation and reduces cutting resistance and power consumption. The open rake face facilitates improved cutting conditions (environment). For example, fly cutters can be ground to an optimized cutting angle based on the material, cutting parameters, and experience, which is not possible with hobs. Furthermore, direct cooling of the cutting zone is difficult with hobs due to their chip flutes. Since flying cutters can create better cutting conditions (environment) than hobs, flying cutters are more advantageous for worm gears that require higher transmission performance and higher tooth surface hardness.

[0014] Fly cutters, which are not commonly known to technicians in this field, have two major advantages over hobs. The most fundamental advantage is that it leaves enough space for the design of the flying cutter's sharpening process, which is easy to control. That is to say, according to the different worm gears and working conditions, the cutting edges (such as chip grooves) can be flexibly sharpened to optimize the cutting angles (such as specially sharpened front cutting edges), and it is convenient to use excellent materials and surface or edge strengthening treatments to obtain high-precision, high-performance, and high-hardness flying cutters, thereby improving productivity, tooth cutting efficiency, and flying cutter service life while ensuring the required accuracy. In particular, at the tooth cutting site, different performance blade shapes and optimized cutting angles can be more conveniently designed and sharpened according to the accuracy, material, working conditions, and experience of the worm gear to be cut. Compared with the radial feed method, the most essential advantages and disadvantages are: 1. Since the number of broken line segments of the enveloping worm gear tooth profile is inversely proportional to the size of the tangential feed, and the productivity is directly proportional to it, the number of strokes of each tooth pitch is also the number of broken line segments expanded by the flying cutter, which can be adjusted within a wide range according to the accuracy requirements (contact spots) of the worm gear to be cut, the module, the number of teeth (or the ratio to the number of heads), the lead angle, the material, the productivity, etc.; the more broken line segments there are, the smaller the tooth profile angularity, the higher the tooth profile accuracy, and the smaller the tooth surface roughness. The number of broken line segments in radial gear hobbing is directly proportional to the number of chip grooves of the hob and inversely proportional to the number of hob heads. It cannot be increased or decreased by changing the processing conditions. This phenomenon is more prominent when hobbing a worm gear with a small number of teeth. Therefore, the tooth surface roughness of fly cutter hobbing can be smaller than that of gear hobbing, and the tooth profile accuracy is higher. Therefore, according to the accuracy and working conditions required by the worm gear to be cut, the processing conditions can be changed, that is, the tangential feed rate is adjusted. Therefore, the contact spot (tooth profile accuracy) and productivity can be artificially controlled during the gear cutting process, especially by using CNC to change the tangential feed rate to obtain the optimal contact spot (the tangential feed rate is inversely calculated based on the requirements of the broken line segments) and higher productivity or rough cutting. Higher productivity (using a larger tangential feed in the section with smaller cutting force) and no principle error (such as overcutting due to radial feed) are particularly important for multi-head, large-module, and small-tooth worm gears. At the same time, because the tangential feed method has a longer cutting length, the tool cutting path length or the number of cycles under load is increased, and the fly cutter also bears the additional cutting volume that should have been removed by the other teeth of the radial hob, increasing the cutting load of the fly cutter. Because the number of fly cutters is extremely small and the cutting volume itself is large, the cutting resistance is also large, causing the fly cutter to wear out prematurely, especially local wear. As a result, the productivity and durability of the fly cutter are not as high as those of the radial feed method. 2. The maximum cutting speed of the fly cutter is affected by the hardness of the material being processed and the fly cutter material, as well as the rigidity of the process system. Under the condition of ensuring the tooth shape accuracy and the durability of the fly cutter, the cutting speed of the fly cutter and the tangential feed should be increased as much as possible to improve the tooth cutting efficiency. The cutting speed and tangential feed can be selected independently and can both be optimized. Taking full advantage of these characteristics can optimize the fly cutter process design and cutting amount, creating conditions for powerful and efficient cutting, and is also one of the conditions for the correct design and use of the fly cutter.

[0015] By means of the tightening screw and the open washer of the present invention, the flying cutter can be accurately positioned and firmly clamped on the tool rod, the strength and rigidity of the tool rod are maximized, the rigidity of the machine tool-tool process system is good, and the blade shape and tooth shape of the flying cutters (groups) with different feed methods and different cutting performances, the respective advantages of the optimized cutting edges and process systems are fully utilized, and the advantages of the flying cutters are fully utilized. For example, the conventional flying cutter with only one layer of cutting edge is designed into a stepped two-layer cutting edge to process a tooth surface at the same time, and it is easier to obtain a high-precision, high-performance and high-hardness flying cutter (group) than a hob. For example, the technical solution of slightly increasing the tooth top height of the flying cutter and the chip groove can effectively improve the cutting conditions (environment) of rough and fine tooth cutting to obtain better cutting conditions than the hob, creating conditions for adopting the optimal high cutting speed, large feed rate and large cutting depth, improving the tooth cutting efficiency and the durability of the flying cutter, and the characteristics of the flying cutter such as no principle error and no chip groove for convenient chip removal, so that the productivity of the flying cutter rolling worm gear is improved compared with the existing technology, and the precision is higher than that of the worm gear hob.

[0016] A further technical solution of the present invention is that the connecting through hole is any one of the following: a round hole, a square hole, and a stepped hole, and the connecting through hole and the positioning part of the flying knife straight handle are straight holes.

[0017] A further technical solution of the present invention is: the size and shape of the connecting through hole are the same, wherein the distance from the plane on the side where the flying knife straight handle is installed to the rotation center line of the knife rod is consistent, and the distance dimension value and the flying knife installation orientation are engraved and marked, an open washer is provided between the plane and the flying knife head positioning plane, and a flat washer is provided or not provided between the plane on the other side and the tightening screw, and the plane is perpendicular to the center line of the connecting through hole.

[0018] With this technical solution, the flat washer is placed between the supporting surface of the tightening screw and the plane, or the supporting surface of the tightening screw is placed directly on the plane. In this case, the small hole of the stepped hole is equivalent to the hole of the flat washer, which plays the role of increasing the contact area of ​​the connected parts, reducing the pressure per unit area, and protecting the surface of the connected parts from damage. The size and shape of the connecting through-holes are set to be the same, and the installation positioning reference is consistent with the distance between the plane on the side where the flying cutter straight handle is installed and the rotation center line of the cutter bar and is engraved with a mark, which facilitates the interchange, production and installation of flying cutters. When the cutting part of the flying cutter is worn and reground, the thickness of the open washer is changed, such as adding a thin open washer or replacing a thick open washer, so that the flying cutter tooth thickness is precisely adjusted to the dividing cylinder of the working worm and prevents movement toward the center of the cutter bar after being subjected to cutting force, while ensuring that the cutting edge parts of the two flying cutter heads extend out of the cutter bar in the same direction.

[0019] A further technical solution of the present invention is that the force applying member is selected from the following

[0020] The force-applying member adopts a screw with a square cylindrical end, which generates an axial force when the screw is tightened. The force-applying terminal of the force-applying member and the threaded part of the force-applying member that generates force are integrated.

[0021] By adopting this technical solution, the spiral clamping mechanism plays the role of clamping, force amplification and self-locking. It is a commonly used, simple and reliable clamping mechanism. In particular, it has the advantages of large force amplification, good self-locking performance and easy use. When the product of the external (acting) force and the lever arm is constant, the force generated by the thread is constant.

[0022] The force-applying component adopts an electro-hydraulic push rod or a liquid or pneumatic cylinder, or a gas-liquid force-amplifying mechanism, which uses liquid, air pressure or electricity as energy to generate axial force, and uses the piston rod of the hydraulic cylinder or pneumatic cylinder as the force-applying terminal. The rotation center line of the force-applying component is provided with an interface for connection with electricity, liquid or gas.

[0023] With this technical solution, when using a hydraulic or pneumatic cylinder, for a given piston pressure area S, the pressure F is proportional to the pressure P, i.e., F = PS. Increasing the pressure increases the corresponding pressure. Because the central bore is relatively small, multiple pistons can be connected in series to multiply the force to avoid the inconvenience of excessive pressure. The pressure of hydraulic oil is much higher than that of air, so the cylinder diameter can be much smaller than that of an air cylinder, typically eliminating the need for a force-boosting mechanism, resulting in a simpler and more compact structure. Liquids are incompressible, resulting in high clamping rigidity, stable operation, reliable clamping, and low noise. The energy for the combined pneumatic and hydraulic pressure-gas-liquid force-boosting mechanism is compressed air, which is pressurized by intensifiers of varying cross-sections before entering the hydraulic cylinder to activate the piston rod. Valve or locks, such as check valves, are provided to self-lock the hydraulic or pneumatic cylinder. When using an electro-hydraulic push rod, the motor drives a bidirectional hydraulic pump in both forward and reverse directions to output pressure oil, which is then delivered to the cylinder via a hydraulic control valve to achieve reciprocating motion of the piston rod. It has many advantages, including being suitable for applications requiring reciprocating push-pull linear motion or clamping, and can be automatically controlled. It has a very reliable automatic overload protection function, can be started under load, and has stepless force adjustment. It uses a fully hydraulic transmission, making it very sensitive and stable, buffering external impact forces. It occupies a small space, is self-locking, and does not require a hydraulic (pneumatic) pressure station; it only requires a power supply. It is a hydraulically driven flexible transmission mechanism that integrates mechanical, electrical, and hydraulic functions. This technical solution uses electricity, liquid, or gas pressure as energy, and when the pressure is constant, the axial force generated is constant.

[0024] The force-applying member is a spring or spring assembly. When compressed, the spring uniformly deforms elastically, generating an axial force that propels the force-applying terminal axially. The force is adjusted using a flat washer or screw. The spring assembly can be a series of multiple disc springs or a set of overlapping cylindrical helical compression springs of varying diameters.

[0025] Using this technical solution, it can be seen from Hooke's law that when the spring undergoes elastic deformation, the elastic force F is proportional to the elongation (or compression) x of the spring, that is, F = kx. When x does not change, the elastic force is constant. k is the elastic coefficient of the material, which is determined by the properties of the material and has nothing to do with other factors. It uses the change in spring length to increase force, and the spring has a buffering effect on impact force.

[0026] A further technical solution of the present invention is that the elastic push rod is a composite component provided with a ball, an adjusting flat washer and a spring, and one end corresponding to the second positioning push rod is a ball.

[0027] With this technical solution, the elastic push rod provided between the first and second positioning push rods uses the adjusting flat washer (by changing the thickness) to adjust the elastic force or compensate for the dimensional change of the oblique flat surface of the flying knife shank on the rotation center line of the knife rod. For example, if the manufacturing error or the flying knife cutting part is worn and reground, it is adjusted to the correct position along its axial direction. This solves the problem of no interference when clamping the two flying knives in the center hole, making the clamping force of the two flying knives tend to be consistent: in order to achieve the opposite end surfaces of the first and second positioning push rods sliding simultaneously onto the oblique flat surface of the flying knife shank to form a close surface contact, and to enable flexible axial movement and rotation in the center hole to avoid jamming, the sphere is provided. According to Hooke's law, if the compression amount remains unchanged, the elastic force is constant. The force is increased by changing the length of the spring, and the spring has a buffering effect on the impact force. A spherical ball is used at one end of the second positioning push rod, so that it has the ability of automatic centering, so as to be compatible with or offset the manufacturing and installation errors of the elastic push rod and the positioning push rod, thereby improving its service life and clamping reliability; and the equivalent friction radius with the end face (point contact) of the second positioning push rod is zero, which improves the transmission efficiency and the flexibility of the positioning push rod in rotating in the center hole, and is more conducive to the opposite end oblique end face of the positioning push rod sliding to the oblique flat surface of the straight handle of the flying cutter to form a close surface contact.

[0028] A further technical solution of the present invention is that the force-applying member is positioned and connected to the center hole, or the force-applying member is slidably positioned with the center hole and connected to the passive end face of the tool rod.

[0029] A further technical solution of the present invention is that the thread of the screw hole at the inlet end of the central hole can be selected as a single-line or single-line fine-pitch thread, and the single-line fine-pitch thread is selected.

[0030] With this technical solution, fine threads have better force amplification and self-locking effects than coarse threads.

[0031] A further technical solution of the present invention is that the thread of the screw hole at the inlet end of the central hole is selected from any one of the following: rectangular thread, trapezoidal thread, and ordinary thread, and the rectangular thread is selected.

[0032] With this technical solution, under the same conditions, since the tooth angle of the rectangular thread is zero, the equivalent friction angle is also zero, so the rectangular thread has better force amplification and self-locking effects.

[0033] A further technical solution of the present invention is: the positioning and clamping mechanism can optionally use one of the following lubricants: lubricating wax, calcium-based grease, molybdenum disulfide or thin oil, and the lubricant is lubricating wax.

[0034] By adopting this technical solution, under the same conditions, friction is reduced, movement is flexible, assembly and disassembly is convenient, transmission efficiency and force-enhancing effect as well as rust prevention are improved; the lubricating wax does not stick to dust, is easy to use, is not easy to lose, has little pollution, is safe and harmless, has a long service life, avoids oil drying up or lack of lubrication, especially the adhesion formed by fat oils, and because the center hole provides a closed space for storing lubricant, it is not easy to lose or be contaminated.

[0035] A further technical solution of the present invention is that the tightening screw can be selected as a coarse thread or a fine thread, preferably a fine thread.

[0036] A further technical solution of the present invention is that a concentric ejector hole is provided at the inlet end of the central hole, which is a 60° tapered hole.

[0037] A further technical solution of the present invention is that the force-applying terminal end face of the force-applying member is a straight end face and is hardened.

[0038] A further technical solution of the present invention is: in order to make the opposite oblique end surfaces of the first positioning push rod and the second positioning push rod slide simultaneously onto the oblique flat plane of the flying knife straight handle to form close surface contact, the inclination angle of the opposite oblique end surfaces of the first positioning push rod and the second positioning push rod is equal to the acute angle θ of the oblique flat plane of the flying knife straight handle, or is 0°.

[0039] With this technical solution, when the tool bar is clamped axially (force-applying member), since the tensioning screw can only generate a force (pulling force) that is directed away from the cutter head, and the intermittent cutting force is always directed toward the center of the tool bar, the cutting force changes the size and direction of the gap on the working tooth side of the tensioning screw thread pair, resulting in unstable cutting and unsatisfactory dynamic stiffness between the tool and the tool bar. Therefore, it is difficult to ensure the tooth surface roughness, and this limits the improvement of productivity. When the opening direction of the acute angle θ is toward the cutter head (the large end of the acute angle θ is in the direction of the cutter head), the force-applying member generates a component force on the cutter toward the cutter head. At this time, the intermittent cutting force causes the cutter and the inclined wedge (surface) to generate a force-increasing and self-locking effect. That is, the greater the cutting force, the tighter and more firmly the cutter is wedged. At the same time, the intermittent cutting force directly impacts the positioning and clamping mechanism. When the opening direction of the acute angle θ is toward the cutter shank (the large end of the acute angle θ is in the direction of the cutter shank), the force-applying member generates a force-increasing and self-locking effect on the cutter and the inclined wedge (surface). In other words, the greater the cutting force, the tighter and more firmly the cutter is wedged. At the same time, the intermittent cutting force directly impacts the positioning and clamping mechanism. When the opening direction of the acute angle θ is toward the cutter shank (the large end of the acute angle θ is in the direction of the cutter shank), the force-applying member generates a force-increasing and self-locking effect on the cutter and the inclined wedge (surface). The flying cutter generates a component force that is directed back to the flying cutter head. At this time, the intermittent cutting force prevents the flying cutter and the inclined surface from forming an inclined wedge, and does not generate a force amplification and self-locking effect. Therefore, the intermittent cutting force will not have a direct impact on the positioning and clamping mechanism. When the angle θ between the inclined flat plane of the flying cutter straight shank and the axis of the flying cutter straight shank is 0°, there is no inclined surface structure, so there is no inclined wedge force amplification and self-locking condition. Therefore, the force-applying component will not generate a component force on the flying cutter that is directed back to or toward the flying cutter head, and the intermittent cutting force will not have a direct impact on the positioning and clamping mechanism.

[0040] Because the smaller the acute angle θ is, the better the double superposition force-enhancing effect of the tightening screw and the bevel is, and the more guaranteed the double self-locking performance is; when the bevel wedge force-enhancing and self-locking conditions are not met (i.e. θ = 0° or there is an acute angle θ but the bevel does not form a bevel and there is no wedging tendency), only the force-enhancing and self-locking of the bevel are missing, and the fly cutter with only the self-locking property of the tightening screw is difficult to loosen; another important characteristic of the bevel structure is the clamping stroke (i.e. axial movement in the center hole) and the distance that the fly cutter moves along its axial direction. As the acute angle θ decreases, the sensitivity of the fly cutter to its axial displacement increases, which is conducive to multiple regrinding of the fly cutter after wear (economic efficiency), but is not conducive to the adjustment of the axial positioning accuracy. For this reason, the acute angle θ should not be selected to be too small.

[0041] A further technical solution of the present invention is that the value range of the acute angle θ is between 3° and 6°.

[0042] A further technical solution of the present invention is that the acute angle θ is 4.5°.

[0043] From the perspective of positioning, the flying cutter rotates and moves around its own axis. After clamping, the two inclined planes of the flying cutter straight shank and the positioning push rod are tightly fitted together. Under the joint action of the flying cutter head positioning plane, the open washer and the cutting force, the freedom of these two directions is limited. When the connecting through hole and the flying cutter straight shank positioning part are non-cylindrical holes, it is only necessary to limit the freedom of the flying cutter movement, especially the clamping of the inclined wedge (i.e. the inclined end face of the positioning push rod) and the composite positioning vertical cross clamping composed of the tightening screw, the positioning inclined surface and the force-applying component. It has automatic centering, high repeat positioning accuracy, reliable clamping, positioning and self-locking are achieved simultaneously, and the resistance to thread loosening is improved to overcome the problem that the two side edges of the flying cutter sometimes alternately participate in cutting, and the teeth generate a large periodic alternating torque along its axis.

[0044] Because the split washer and angled wedge are used for clamping and positioning, the position of the fly cutter along its axis can be adjusted by adjusting the thickness of the split washer. Even after axial adjustment for wear and resharpening, the fly cutter's tooth thickness remains on the indexing cylinder of the working worm. The fly cutter's axial positioning accuracy is insensitive to the travel distance of the positioning mandrel, enhancing its ability to be repeatedly resharpened. The degree of freedom of the fly cutter to rotate about its axis within the cylindrical hole is determined by the contact accuracy of the two surfaces joined by the angled wedge.

[0045] By adopting this technical solution, since the positioning and clamping mechanism is arranged in the center hole and facilitates the force of the tightening screw, the length of the flying knife straight shank must exceed the center hole, the contact length of the flying knife straight shank is increased, and under the action of the tightening screw, the relative positioning is more reliable and the stability is better, thereby improving the repeated positioning accuracy and the service life of the connecting through hole.

[0046] This technical solution utilizes a wedge (surface) at the terminal end of the positioning and clamping mechanism, resulting in a large contact area. This mechanism not only clamps, amplifies, and self-locks, but also provides automatic centering. This provides a simple, reliable, and highly accurate clamping and positioning structure. In particular, it is a composite clamping and dual self-locking mechanism comprised of two simple mechanisms: the wedge and the spiral clamp. Furthermore, the cutting force causes the cutter and the wedge (surface) to produce a force-amplifying and self-locking effect, significantly improving clamping reliability. When the force-applying member applies force, the two inclined planes, acting in concert with the open washer, closely align, simultaneously achieving accurate positioning and clamping of the cutter on the arbor. This results in dual vertical clamping and triple self-locking properties generated by the tensioning screw, the wedge, and the force-applying member, resulting in excellent positioning and clamping performance. This mechanism is particularly suitable for securely clamping twin worm gear cutters with high cutting forces and high precision.

[0047] A further technical solution of the present invention is: the outer circumferential surfaces of the first positioning push rod and the second positioning push rod are provided with multiple sections of annular grooves with guide angles, and the annular grooves are started and ended at both ends of the first positioning push rod and the second positioning push rod and the end surfaces are hardened.

[0048] A further technical solution of the present invention is: the angle δ between the oblique flat plane of the flying cutter straight shank and the flying cutter zero rake angle front cutting edge should be determined according to the type, precision grade, size and rotation direction of the working worm gear when the flying cutter is clamped on the tool rod, so that the flying cutter zero rake angle front cutting edge is exactly on the normal or axial plane of the working worm gear; when the flying cutter zero rake angle front cutting edge is exactly on the normal plane of the working worm gear, the angle δ between the oblique flat plane of the flying cutter straight shank and the flying cutter zero rake angle front cutting edge is equal to the working worm gear indexing cylindrical lead angle γ; when the flying cutter zero rake angle front cutting edge is exactly on the axial plane of the working worm gear, the angle δ between the oblique flat plane of the flying cutter straight shank and the flying cutter zero rake angle front cutting edge is 0°.

[0049] This technical solution comprehensively considers the differences in the cutter axis, cutting force and tool shank diameter during normal clamping, whether it is metal or non-metal, material strength (properties) and manufacturing convenience, the means of grinding the front cutting edge, the tooth shape and the cutting conditions of the cutting edges on both sides. For example, when rolling an Archimedean worm gear, when the cutter rake angle is 0°, the tooth shape of the cutter in the axial direction is a straight line, and the working rake angles of the cutting edges on both sides are different (in order to improve the cutting conditions, a special grinding method is adopted to grind the rake face), and the tooth shape of the cutter in the normal direction is a (drum-shaped) curve that is the same as the normal section of the Archimedean worm, and the working rake angles of the cutting edges on both sides are the same.

[0050] The beneficial effects of the present invention are:

[0051] 1. From the perspective of material mechanics, this technical solution minimizes the weakening of the strength and rigidity of the tool bar, and the tool bar length can be set to the shortest and the diameter to the largest, which greatly improves the connection rigidity and reliability between the fly cutter and the tool bar, reduces vibration and improves cutting conditions. Since the positioning and clamping mechanism is located in the center hole and does not occupy axial space, it avoids the difficulties in manufacturing the fly cutter and tool bar caused by the axial arrangement of the fly cutter along the tool bar, the poor rigidity of the tool bar, and the long tangential cutting time. At the same time, it improves safety, creates conditions for the fly cutter processing of the integral shank worm gear hob, and solves the bottleneck of the difficulty in manufacturing multi-head worm gear hobs with small working worm diameters.

[0052] 2. The combination of the tightening screw and the open washer integrates the radial fine adjustment, clamping, and self-locking threaded connection mechanism, with high adjustment accuracy. With the help of measuring instruments, the radial position of the flying cutter extending out of the tool rod can be accurately adjusted within a certain range. The flying cutter has high positioning accuracy and precise positioning, double vertical clamping, double superposition force of the inclined wedge and the tightening screw, large clamping force, multiple self-locking effects, and the flying cutter is difficult to loosen after clamping, which is suitable for strong cutting. The structure is simple and compact, and it is easy to manufacture, use and maintain.

[0053] In particular, the double superimposed force amplification and self-locking properties generated by the tightening screw and the bevel wedge can obtain better and more reliable positioning and clamping performance, especially the intermittent cutting force causes the flying cutter and the bevel wedge (surface) to produce force amplification and self-locking effects. In this way, the greater the cutting force, the tighter and more firmly the flying cutter is wedged, the dynamic stiffness between the tool and the tool rod is good, which is beneficial to productivity, and the cutting stability can ensure the tooth surface roughness. Under the joint action of the force generated by the tightening screw and the force-applying component, the double vertical clamping and triple self-locking properties generated by the tightening screw, the bevel wedge and the force-applying component can obtain better positioning and clamping performance.

[0054] 3. Due to the addition of a fly cutter, there is no need for manual head separation or the manual head separation (error) is reduced and it can be used for rough cutting (such as with a chip dividing groove), which improves the worm gear envelope (precision) effect and productivity and the durability of the fly cutter. Especially in the process of precision cutting, the durability of the fly cutter between two re-grindings is extremely important. This is especially critical for precision worm gears with multiple heads, large modules, a large number of teeth, and harder materials.

[0055] When one of the fly cutters only serves as an "ineffective enveloping cutter tooth", the cutting edges of the fly cutter are provided with chip grooves, or the top height of the fly cutter tooth is slightly increased. In this way, the top edge of the fly cutter with the "effective enveloping cutter tooth" does not participate in cutting, thereby changing the cutting pattern and improving the cutting conditions. The use of technical solutions such as chip grooves can achieve efficient rolling cutting with large cutting depth and large tangential feed, thereby improving the tooth cutting efficiency, productivity and durability of the fly cutter. Under the conditions of the same tangential feed rate, the final enveloping effect of the worm gear tooth surface remains unchanged, turning the disadvantage of the "ineffective enveloping cutter tooth" that only has cutting function but no enveloping function into an advantage, thereby increasing the service life of the tool, thereby eliminating the П and Γ shaped chips with the most unfavorable cutting conditions, further improving the durability of the fly cutter between two regrindings, and optimizing the edge shape structure of the fly cutter cutting edge and the fly cutter combination form.

[0056] We can also further optimize the process design by taking advantage of the fact that the fly cutter has a simple structure and most of them are single teeth. The fly cutters with high precision, high performance and high hardness are easy to obtain and the working conditions are optimized. That is, the fly cutter groups with different cutting performances (such as coarse and fine) and the feeding (radial and tangential feed) methods, heads and tooth shapes are set up in the double fly cutter, which gives full play to the respective advantages of the feed method and tooth shape, optimized blade shape and cutting angle and process system to improve the cutting conditions. The optimized cutting amount further improves the productivity and the durability of the fly cutter between two re-grindings, especially when rough cutting the teeth, the radial feed method is used to make up for the cutting The inherent deficiency of low tangential feed productivity or the use of large cutting depth and large or variable tangential feed to obtain higher productivity, and the use of small or variable tangential feed during fine tooth cutting to improve or optimize the tooth profile accuracy (contact spot) and productivity (tooth cutting efficiency), so according to the required accuracy and working conditions of the worm gear to be cut, the tooth profile accuracy and productivity can be improved or optimized by adjusting the size of the tangential feed and the cutting method during the tooth cutting process, so that the productivity of the fly cutter rolling worm gear is improved compared with the existing technology, and the accuracy is higher than the accuracy of the worm gear hobbing.

[0057] In addition, the process scheme that matches the effective cutting depth of concave parts such as chip grooves with the feed rate and the trajectory of fly cutter cutting is more conducive to optimizing cutting parameters and improving gear cutting efficiency and the durability of the fly cutter.

[0058] 4. The use of balls and lubricating wax allows each component to move freely without obstruction, easy disassembly and assembly, flexible movement, simple structure, easy material acquisition and low cost, which simplifies the manufacture and maintenance of the tool bar.

[0059] 5. The included angle δ between the oblique cut plane of the flying tool straight shank and the flying tool's zero rake angle rake surface is independent of the included angle θ with the flying tool's straight shank axis, and is also independent of the inclination angle θ of the positioning push rod, that is, there is no principle error in the included angle δ between the flying tool's zero rake angle rake surface and the tool arbor's rotation centerline.

[0060] In summary, this technical solution has a simple and compact structure, is easy to manufacture, use and maintain, has low cost, the positioning and clamping mechanism moves freely, there is no principle error (such as the angle θ), the fly cutter has high fine-tuning and repeated positioning accuracy, the clamping force is large and difficult to loosen, the process system has good rigidity, and it gives full play to the advantages of the radial feed method, the fly cutter and the fly cutters with different cutting performances, and is convenient for strong, efficient and high-quality cutting with optimized cutting amounts. In particular, in the tooth cutting process, the tooth profile accuracy (contact spot) and productivity can be improved or optimized by regulating the size of the tangential feed and the cutting method, thereby improving the durability and service life of the fly cutter. The productivity and tooth profile accuracy of the fly cutter rolling worm gear are improved over the existing technology, and the accuracy is higher than that of the worm gear hob, especially for the rolling of multi-head, large-module and small-tooth worm gears with small working worm diameter and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1Schematic diagram of the clamping of the fly cutter bar of the medium and small module worm gear in the existing technology

[0062] Figure 2 Schematic diagram of the clamping of the existing large-module flying knife arbor with an arc surface (r is the radius of the concave arc groove of the cylindrical part of the round tie rod with a screw)

[0063] Figure 3 Schematic diagram of the clamping of the existing large-module flying knife arbor with an inclined surface (β is the acute angle of the bevel plane of the cylindrical part of the round tie rod with a screw)

[0064] Figure 4 This is a structural diagram of Example 1 of the present invention (R is the radius of the working worm indexing cylinder, m is the axial module of the working worm, δ is the angle between the oblique flat plane of the flying tool straight shank and the flying tool zero rake angle front cutting edge, θ is the angle between the oblique flat plane of the flying tool straight shank and the axial centerline of the flying tool straight shank and the inclination angle of the oblique end face of the positioning push rod) features: right-handed, the flying tool is placed in the normal direction, the force-applying member adopts a screw with a square cylindrical end, the force-applying member is positioned and connected to the center hole, the opening direction of the acute angle θ is toward the flying tool head, and δ = γ.

[0065] Figure 5 This is a structural diagram of Example 2 of the present invention. The features are: left-hand rotation, the flying cutter is placed in the normal direction, the force-applying component adopts an electro-hydraulic push rod or a liquid or pneumatic cylinder and a gas-liquid force-amplifying mechanism, the force-applying component is slidably positioned with the center hole and connected to the passive end face of the tool rod, the opening direction of the acute angle θ is toward the flying cutter head, and δ = γ.

[0066] Figure 6 This is a structural diagram of embodiment 3 of the present invention. Features: left or right rotation, the flying cutter is placed in the axial direction, the force-applying component is a spring or a spring assembly, the force-applying component is slidably positioned with the center hole and connected to the passive end face of the tool rod, the opening direction of the acute angle θ is toward the flying cutter head, δ = 0°.

[0067] Figure 7 This is a structural diagram of Example 4 of the present invention. Features: right-handed, the flying cutter is placed in the normal direction, the force-applying member adopts a screw with a square cylindrical end, the force-applying member is positioned and connected to the center hole, the opening direction of the acute angle θ is toward the straight handle of the flying cutter, δ=γ, the connecting through hole is a stepped hole, and no flat washer is provided.

[0068] Figure 8 This is a structural diagram of Example 5 of the present invention. Features: right-handed, the flying cutter is placed in the normal direction, the force-applying member uses a screw with a square cylindrical end, the force-applying member is positioned and connected to the center hole, θ=0°, δ=γ. DETAILED DESCRIPTION

[0069] Implementation Method 1

[0070] like Figure 4The clamping structure of a double worm gear flying cutter shown in the figure includes a tool rod 1, which consists of an active end with a tapered shank (not shown in the figure) and a slender passive end. A center hole 4 is provided at the passive end facing the active end and concentric with the rotation center line of the tool rod 1. Two parallel connecting through holes 2 for installing and tightening the flying cutter straight handle 72 are radially provided along the rotation center line of the tool rod 1 (axially) at an appropriate position in the middle of the tool rod 1. The center distance between the connecting through holes 2 is the axial tooth pitch πm of a working worm. Flat surfaces 21 are provided at the two straight-viewing ends of the connecting through holes 2, wherein the flat surfaces 21 on the same side of the rotation center line of the tool rod 1 are provided with a tightening screw 10, and are connected to the screw hole provided on the axial center line of the flying cutter straight handle 72. The center line of the connecting through hole 2 is perpendicular to and passes through the rotation center line of the tool rod 1, and is connected with the center hole 4. The tool rod 1 can be selected as a symmetrical cross-section shaft such as a circular shaft, a variable diameter shaft, a polygonal shaft, or a circular shaft to be suitable for high-speed rolling; the plane 21 can be selected as the bottom plane of a countersink or a groove, the plane of the outer periphery of a polygonal shaft, etc. This embodiment takes the countersink of a through hole as an example.

[0071] A further technical solution is: the connecting through hole 2 can be any one of the following: a circular hole, a square hole, or a stepped hole; the circular hole can be a cylindrical hole or a Sui circular hole, the square hole can be a quadrilateral hole or a hexagonal hole, the stepped hole can be a two-stage stepped hole or a multi-stage stepped hole, the stepped holes are all circular holes or square holes and a combination of circular holes and square holes, but the small hole is a through hole; the positioning part of the connecting through hole 2 and the flying knife straight handle 72 is a straight hole, which satisfies the sliding fit between the flying knife straight handle 72 and the inner circumference of the connecting through hole 2, thereby realizing that the flying knife 7 can slide and position axially along the connecting through hole 2.

[0072] By adopting this technical solution, when the connecting through hole 2 and the positioning part of the flying cutter straight handle 72 are non-cylindrical holes (such as square holes), the freedom of rotation of the flying cutter 7 is limited. Even if the force-applying component 6 does not apply force, the flying cutter will never move or rotate under the action of the tightening screw 10. It is particularly suitable for rough cutting of teeth with large cutting depth and large feed rate.

[0073] A further technical solution is: to ensure that there is a good contact state and anti-loosening performance between the supporting surface of the tightening screw 10 and the flat surface 21; to ensure that the flying cutter 7 is installed in the connecting through hole 2 without moving and can be axially adjusted in size to adjust the radial position of the flying cutter 7 on the tool rod 1, because there is a necessary radial clearance when the working worm and the worm wheel are engaged, the tooth top height of the flying cutter is increased by a certain amount compared with the working worm, in order to facilitate positioning measurement and repeated positioning, the flying cutter 7 is accurately installed and can continue to be used after sharpening, and there is a unified positioning installation reference so that the cutting edge parts of the two flying cutter heads are in The connecting hole 2 is identical in size and shape to the working worm and extends out of the arbor in the same direction. The flat surface 21 on the side where the fly cutter shank 72 is installed is aligned with the rotational centerline of the arbor 1 and is inscribed with the distance dimension and the orientation of the fly cutter 7. A split washer 3 is positioned between the flat surface 21 and the fly cutter head positioning flat surface 71, while a flat washer 9 is positioned between the flat surface 21 and the tensioning screw 10 on the other side. The flat surface 21 is perpendicular to the centerline of the connecting hole 2 to precisely adjust the fly cutter tooth thickness to coincide with the indexing cylinder of the working worm and prevent movement toward the center of the arbor 1 under cutting forces. The tensioning screw 10 is a screw with a tightening head, such as a hexagonal head bolt or a hexagon socket head cap screw. The head of the tensioning screw 10 must not interfere with the worm gear being cut during cutting. Alternatively, all flat surfaces 21 can be aligned with the rotational centerline of the arbor 1 and inscribed with the distance dimension.

[0074] With this technical solution, the flat washer 9 is placed between the supporting surface of the tightening screw 10 and the plane 21, which increases the contact surface area of ​​the connected parts, reduces the pressure per unit area and protects the surface of the connected parts from being damaged. When the fly cutter 7 is installed or its cutting portion is worn and regrinded, the thickness of the split washer 3 can be changed, such as by adding a thin split washer or replacing a thick split washer 3, to facilitate precise adjustment of the fly cutter tooth thickness so that it is exactly on the indexing cylinder of the working worm and prevents movement toward the center of the arbor 1 after being subjected to cutting forces. This eliminates the need to remove the entire fly cutter 7 from the connecting through hole 2, achieving the purpose of convenient and quick adjustment and saving auxiliary time. When the fly cutter 7 rotates, the split washer 3 is restricted by the plane 21 and the fly cutter head positioning plane 71, and will not fly out and injure people or objects under the action of centrifugal force. At the same time, it ensures that the cutting edge portions of the two fly cutter heads 74 extend out of the arbor 1 in the same direction. The radial position of the fly cutter extending out of the arbor 1 is one of the conditions for correct use. Therefore, the fly cutter and arbor are properly designed, creating conditions for correct use. The two working planes of the split washer 3 are parallel, and of course, a non-split flat washer can also be selected.

[0075] The positioning and clamping mechanism 8 is disposed within the central hole 4. A force-applying member 6, a plurality of balls 12, a first positioning ejector rod 5A, a first fly cutter 7A, an elastic ejector rod 13 extending through a hole in the obliquely flattened flat surface 73 of the straight shank of the first fly cutter 7A, a second positioning ejector rod 5B, and a second fly cutter 7B are disposed in sequence from the passive end face 11 inward. The elastic ejector rod 13 then passes through a hole in the obliquely flattened flat surface 73 of the straight shank of the first fly cutter 7A, the second positioning ejector rod 5B, and the second fly cutter 7B. The cylindrical end of the elastic ejector rod 13 is inserted into a concentric positioning blind hole 53 at one end of the oblique end face 51 of the first positioning ejector rod 5A. The force-applying member 6 can be applied manually or mechanically. Manual force application requires the use of various force-amplifying mechanisms. Due to limited and unstable manpower, when mechanical clamping is employed, the original clamping force (acting force) can be continuously applied, ensuring reliable clamping and eliminating the need for a self-locking mechanism.

[0076] The ball 12 is a spherical body with high rigidity, such as a hardened steel ball or even a steel ball in a discarded deep groove ball bearing. Using the ball 12 as part of the force transmission medium has a simple structure, is easy to obtain and has low cost, is flexible in operation, has low rolling friction loss, and has low requirements for the hole it matches. It can even roll normally in a curved hole (or a tool rod with a slight curve), simplifying the high requirements for deep hole processing. For example, this section of the hole is processed with an ordinary twist drill, and the manufacturing process and tool rod maintenance are simple.

[0077] With this technical solution, the concentric positioning blind hole 53 provided at one end of the oblique end surface 51 of the first positioning push rod 5A supports and positions the elastic push rod 13. When the force-applying member 6 applies force, the ball 12 causes the oblique end surface 51 of the first positioning push rod 5A to slide onto the oblique flat surface 73 of the flying knife shank, forming a close surface contact, thereby securing the first flying knife 7A within the connecting through-hole 2. Simultaneously, the first positioning push rod 5A passes through the hole in the oblique flat surface 73 of the first flying knife 7A shank through the elastic push rod 13, causing the oblique end surface 51 of the second positioning push rod 5B to slide onto the oblique flat surface 73 of the flying knife shank, forming a close surface contact, thereby securing the second flying knife 7B within the connecting through-hole 2. This allows the first positioning push rod 5A to be very short, enabling it to move and rotate more freely within the center hole 4.

[0078] Due to the force generated by the tightening screw 10 and the positioning clamping mechanism 8, the point of force applied to the flying cutter straight handle 72 is far away from the force point of the flying cutter 7. Since the open washer 3 is provided between the flying cutter head positioning plane 71 and online measurement is performed with the aid of precision measuring instruments, the accuracy, consistency and reliability of the repeated positioning of the double worm gear flying cutter are improved.

[0079] A further technical solution is that the force-applying member 6 uses a screw with a square cylindrical end, and an axial force is generated when the screw is tightened. At this time, the force-applying terminal 61 (i.e., the cylindrical end) and the threaded portion 62 of the force-applying member 6 that generates force are integrated.

[0080] Those skilled in the art will appreciate that when the fly cutter 7 is axially clamped within the center hole 4, the equivalent friction radius of the sphere 12 between the force-applying terminal 61 and the first positioning push rod 5A is zero. The axial (clamping) force generated by the screw is directly proportional to the applied force and the lever arm, and inversely proportional to the screw diameter. This force is typically tens or even hundreds of times greater than the applied force, resulting in a significant clamping force and thus a significant force-amplifying effect. Furthermore, the angle θ between the obliquely cut flat surface 73 of the fly cutter shank and the axis of the fly cutter shank 72 is relatively small, resulting in a negligible effect on the clamping force within the center hole 4. The force-applying member 6 utilizes the screw's force-amplifying and self-locking properties to create conditions for the proper use of the fly cutter and cutter bar.

[0081] In order to facilitate free movement, improve precision, and facilitate assembly and production, the center hole 4 is a three-stage stepped hole, that is, from the end face 11 close to the passive end of the tool rod, there are screw holes 42 with larger diameters inward, followed by a first circular light hole 41A with smaller and longer diameters, and the rest is a second circular light hole 41B between the two connecting through holes 2 and slightly smaller than the first circular light hole 41A. The first circular light hole 41A and the second circular light hole 41B are respectively provided with the first positioning push rod 5A and the second positioning push rod 5B that can slide with the inner hole wall. Because the ball 12 can roll and move freely and flexibly in the curved first circular light hole 41A, the first circular light hole 41A is provided with the ball 12 that can slide and roll with the inner hole wall.

[0082] A further technical solution is that the elastic push rod 13 is a composite component provided with a ball, an adjusting flat washer and a spring, and one end corresponding to the second positioning push rod 5B is a ball.

[0083] With this technical solution, the elastic push rod 13 provided between the first positioning push rod 5A and the second positioning push rod 5B uses the adjusting flat washer (by changing the thickness) to adjust the elastic force or compensate for the dimensional changes of the flat beveled flat surface 73 of the flying knife shank on the rotation centerline of the knife bar. For example, the adjustment is made to the correct position along the axial direction due to manufacturing errors or the wear and tear of the flying knife cutting part after re-grinding. This solves the problem of no interference when clamping the two flying knives 7 in the center hole 4, making the clamping force of the two flying knives 7 tend to be consistent. In order to achieve the simultaneous sliding of the opposing oblique end surfaces 51 of the first positioning push rod 5A and the second positioning push rod 5B onto the flat beveled flat surface 73 of the flying knife shank to form a close surface contact, the spherical ball is provided to enable the elastic push rod 13 to move and rotate flexibly in the axial direction within the center hole 4 to avoid jamming. According to Hooke's law, if the compression amount remains unchanged, the elastic force is constant. The force is increased by changing the spring length, and the spring has a buffering effect on the impact force. The second positioning push rod 5B is provided with a spherical end, which provides self-aligning capability, thereby compatibility with or offsetting manufacturing and installation errors of the elastic push rod 13 and the positioning push rod 5, improving their service life and clamping reliability. The equivalent friction radius with the end face (point contact) of the second positioning push rod 5B is zero, thereby improving transmission efficiency and the flexibility of the positioning push rod 5 in rotating within the center hole 41, and further facilitating the opposite end oblique end face 51 of the positioning push rod 5 to slide onto the oblique flat surface 73 of the flying knife straight handle to form a close surface contact. The opposite end face of the second positioning push rod 5B and the sphere of the elastic push rod 13 can be a straight end face or a concave or convex spherical surface with a radius greater than the radius of the sphere. A straight end face is preferred due to its simplicity in manufacturing and good centering properties.

[0084] At the same time, the ball is a spherical body with high rigidity, such as a hardened steel ball, or even a steel ball in a discarded deep groove ball bearing; the elastic push rod 13 has a built-in ball as a partial force transmission medium, which has a simple structure, convenient material acquisition and low cost, flexible operation, low rolling friction loss, low requirements for the hole it matches, and can even roll normally in a curved hole. The manufacturing process is simple, which is conducive to adjusting the movement of the flat washer and the spring.

[0085] The elastic push rod 13 uses a spring and an adjusting flat washer to solve the problem of over-positioning and non-interference during clamping, and makes the clamping force of the two flying knives 7 tend to be consistent. The ball solves the problem of working flexibility, so the flying knife and the knife rod are properly designed, which creates conditions for correct use.

[0086] A further technical solution is that the threaded portion 62 of the square cylindrical end screw of the force applying member 6 is positioned and connected to the screw hole 42 of the central hole 4 .

[0087] A further technical solution is that the thread of the screw hole 42 (the entrance end of the center hole 4) can be a single-start or single-start fine-pitch thread. Because fine-pitch threads provide better force amplification and self-locking effects than coarse-pitch threads, single-start fine-pitch threads are preferred. Conventional threads are classified into coarse, fine, and ultra-fine threads; trapezoidal threads are classified into single-start and multi-start threads. Single-start threads of the same nominal diameter may have one or more pitches.

[0088] A further technical solution is: the thread of the screw hole 42 (the entrance end of the central hole 4) is selected from the following: rectangular thread, trapezoidal thread, and ordinary thread, and the rectangular thread is selected.

[0089] With this technical solution, under the same conditions, since the tooth angle of the rectangular thread is zero, the equivalent friction angle is also zero, so the rectangular thread has better force amplification and self-locking effects.

[0090] A further technical solution is: the positioning and clamping mechanism 8 can optionally use one of the following lubricants, lubricating wax, calcium-based grease, molybdenum disulfide or thin oil. Because lubricating wax does not stick to dust, is easy to use, has less pollution, is safe and harmless, has a long service life, and avoids the drying up of oil or lack of lubrication, especially the adhesion formed by lipid oils. The lubricant is selected as lubricating wax.

[0091] By adopting this technical solution, under the same conditions, friction is reduced, movement is flexible, assembly and disassembly is convenient, transmission efficiency and force amplification effect as well as rust prevention are improved. Since the center hole provides a closed space for storing lubricant, it is not easy to lose or be contaminated, so the fly cutter and the cutter bar are also used and maintained correctly.

[0092] A further technical solution is that the tightening screw 10 can be selected as a coarse thread or a fine thread. In order to improve the self-locking property and clamping force of the thread, a fine thread is preferably used.

[0093] A further technical solution is: in order to facilitate the processing, inspection or trimming of the tool rod 1, a concentric ejector hole 43 is provided at the inlet end of the center hole 4, and the concentric ejector hole 43 is a 60° tapered hole.

[0094] A further technical solution is: the end face of the force terminal (i.e., the cylindrical end) 61 of the square cylindrical end screw (force-applying component) 6 is a straight end face and is hardened. Because a ball 12 is provided between it and the first positioning push rod 5A, it has the ability to automatically adjust its centering to be compatible with or offset the manufacturing and installation errors of the screw hole 42 and the first positioning push rod 5A, thereby improving its installation accuracy, service life, and clamping reliability; and the equivalent friction radius of the end face of the force terminal 61 and the first positioning push rod 5A and the ball 12 (point contact) is zero, which improves the force amplification ratio and efficiency of the square cylindrical end screw 6, while making the first positioning push rod 5A rotate flexibly in the center hole 41A, so that the opposite end oblique end face 51 of the first positioning push rod 5A slides to the oblique flat surface 73 of the straight handle of the flying knife to form a close surface contact. The opposite end faces of the force-applying terminal 61, the first positioning push rod 5A and the sphere 12 can be straight end faces or concave or convex spherical surfaces with a radius greater than the radius of the sphere 12. Straight end faces are preferred due to their simplicity in manufacturing and good centering properties.

[0095] When the opening direction of the acute angle θ is toward the flying cutter head 74, under the action of the axial clamping force (force-applying member 6) along the tool rod 1, the flying cutter 7 generates a component force toward the flying cutter head 74, and always generates a cutting force toward the center of the tool rod 1 during cutting. At this time, the intermittent cutting force causes the flying cutter 7 and the inclined wedge (surface) to produce a force-increasing and self-locking effect. At the same time, the intermittent cutting force directly impacts the positioning clamping mechanism 8, resulting in a poor clamping effect of the positioning clamping mechanism 8; when the tightening screw 10 generates a force back to the flying cutter head 74, those skilled in the art know that it complies with The wedge-type force amplification and self-locking conditions, where tightening the tensioning screw 10 generates a double superimposed force amplification (tensioning screw and wedge) and self-locking, cannot eliminate the clearance between the threaded working tooth flanks. Under the combined action of the tensioning screw 10 and the cutting force directed toward the center of the tool arbor 1, the fly cutter 7 tends to move toward the center of the tool arbor 1, further compacting the fly cutter head positioning plane 71 against the open washer 3 on the plane 21. This is also achieved through online measurement using precision measuring instruments to improve the repeatability and positional accuracy of the twin worm gear fly cutter 7. The fly cutter 7 also prevents movement or rotation. In particular, the double superimposed force amplification (locking screw and wedge) and self-locking generated by tightening the tensioning screw 10, combined with the intermittent cutting force that creates a force amplification and self-locking effect between the fly cutter 7 and the wedge (surface), results in a greater cutting force, a tighter and more secure wedging of the fly cutter, and improved dynamic stiffness between the tool and tool arbor, resulting in optimal positioning and clamping performance. This is the optimal implementation.

[0096] When the square cylindrical end screw (force-applying member) 6 is tightened, the cylindrical end 61 of the square cylindrical end screw moves axially together and generates force, which causes the first positioning push rod 5A to move axially through the ball 12. At the same time, the spring of the elastic push rod 13 is compressed and generates axial force, causing the second positioning push rod 5B to move axially. The oblique end surfaces 51 of the opposite ends of the first positioning push rod 5A and the second positioning push rod 5B slide simultaneously to the oblique flat surface 73 of the straight handle of the flying knife to form a close surface contact, and under the combined action of the dual force amplification and self-locking generated by the tightening screw 10 and the oblique wedge, the first flying knife 7A and the second flying knife 7B are fastened in the corresponding connecting through hole 2 at the same time.

[0097] A further technical solution is: to ensure that the opposing oblique end surfaces 51 of the first and second positioning push rods simultaneously slide onto the obliquely cut flat surface 73 of the flying knife shank, thereby forming close surface contact and ensuring reliable clamping and accurate flying knife positioning, the inclination angle of the opposing oblique end surfaces 51 of the first and second positioning push rods 5A, 5B is equal to the acute angle θ of the obliquely cut flat surface of the flying knife shank, or is 0°. In other words, the inclination angle of the opposing oblique end surfaces 51 of the first and second positioning push rods 5A, 5B is consistent with the angle of the obliquely cut flat surface 73 of the flying knife shank.

[0098] On the one hand, the smaller the value of the acute angle θ, the better the superimposed force-enhancing effect of the tightening screw 10 and the bevel wedge, and the more guaranteed the dual self-locking performance of the screw and the bevel wedge; on the other hand, another important characteristic of the inclined surface structure is the clamping stroke (i.e., axial movement in the center hole 4) and the corresponding movement distance of the fly cutter 7 along its axial direction. If the acute angle θ decreases, the sensitivity of the fly cutter 7 to its axial displacement increases, which is conducive to the regrinding of the fly cutter 7 after wear, but is not conducive to the adjustment of the axial positioning accuracy. For this reason, the acute angle θ should not be selected to be too small.

[0099] A further technical solution is that the value range of the acute angle θ is between 3° and 6°.

[0100] A further technical solution is: in order to facilitate the adjustment and axial positioning accuracy of the flying cutter 7 after regrinding, and to obtain greater pulling force and reliability, the acute angle θ is selected to be 4.5°.

[0101] Those skilled in the art know that the stress state of the flying cutter 7 when clamped along its axial direction is composed of a double superposition of the inclined wedge and the tightening screw 10, and a double self-locking effect is produced by the inclined wedge and the thread. When the acute angle θ between the inclined flat plane 73 of the flying cutter straight handle and the axis of the flying cutter straight handle 72 is 4.5°, the clamping force of the inclined wedge is about 3.5 times the applied force, and the pulling force generated by the tightening screw 10 is more than dozens of times the applied force. The clamping force of the above forces combined is hundreds of times the applied force. Obviously, the force acting on the flying cutter 7 is very large, and the clamping force generated is very large. Therefore, the ingenious combination of the inclined wedge clamping structure and the screw tightening structure has a great force-enhancing and self-locking effect.

[0102] To sum up, the double superposition force amplification and double self-locking of the bevel wedge and the tightening screw 10, and the positioning vertical cross clamping composed of the square cylindrical end screw (force-applying component) 6 have automatic centering, high repeat positioning accuracy and reliable clamping, and positioning, double clamping and triple self-locking are achieved simultaneously, especially when the connecting through hole 2 and the straight handle positioning part of the flying tool 7 are square holes; it meets the requirements that the flying tool 7 is reliably clamped after being installed in the tool rod 1, and the flying tool does not move or rotate during cutting.

[0103] Under the dual vertical action of the axial tension along the connecting through hole 2 (tightening screw 10) and the axial clamping force along the tool rod 1, the acute angle θ is small, and the dual superimposed (increased) force and self-locking produced by the tightening screw 10 and the inclined wedge (the inclined surface of the positioning push rod) have good self-locking and clamping reliability, and can obtain better positioning and clamping performance, especially the dual vertical clamping and triple self-locking produced by the tightening screw 10, the inclined wedge and the force-applying member 6, which can obtain excellent positioning and clamping performance. The flying cutter 7 will not move or rotate, and can meet the requirements of large cutting force and large lead angle.

[0104] A further technical solution is: in order to facilitate the flexible and free sliding and rotation of the positioning push rod 5 along the circular light hole 41, in order to reduce the contact area between the positioning push rod 5 and the circular light hole 41 and to accommodate lubricants and debris, the circumferential surface of the positioning push rod 5 or the circular light hole 41 can be provided with multiple sections of circular annular grooves with guide angles. In order to facilitate processing, it is preferred that the outer circumferential surfaces of the first positioning push rod 5A and the second positioning push rod 5B are provided with multiple sections of circular annular grooves 52 with guide angles, and the starting and ending points of the circular annular grooves 52 are set at the two ends of the first positioning push rod 5A and the second positioning push rod 5B. In this way, it is easy to pass through this part when installing and disassembling the positioning push rod 5 and when it is slightly bent or the two ends are squeezed and deformed for a long time. In order to improve the service life of the positioning push rod 5 and reliable clamping, the two end surfaces of the first positioning push rod 5A and the second positioning push rod 5B are hardened.

[0105] Generally, the rake angle of the flying cutter is 0°. At this time, the flying cutter front cutting surface 75 coincides with the axis of the flying cutter straight shank 72. In order to improve productivity or roll cut polymer materials (MC nylon), a positive rake angle is selected. The rake surface when the flying cutter rake angle ≠0° is projected onto the flying cutter rake surface 75 with a rake angle of 0° or the rake angle of the rake surface 75 is 0°. This flying cutter rake surface 75 is called the flying cutter zero rake angle rake surface 75; reasonable selection and sharpening of the flying cutter front and back angles can significantly improve the cutting performance and improve the durability and productivity of the tool, and the tooth surface roughness and power consumption are also small; when the flying cutter 7 is clamped on the tool rod 1, the flying cutter zero rake angle rake surface 75 is exactly in the normal plane of the working worm, that is, the angle between the flying cutter zero rake angle rake surface 75 and the rotation centerline of the tool rod 1 is γ, so that the cutting edge part of the flying cutter head 74 is in the same position as the working worm.

[0106] A further technical solution is: the angle δ between the inclined flat plane 73 of the flying cutter straight shank and the flying cutter zero rake angle front cutting edge 75 should be such that when the flying cutter 7 is clamped on the tool rod 1, the flying cutter zero rake angle front cutting edge 75 is exactly in the normal plane of the working worm, that is, δ = γ.

[0107] For example, when rolling an Archimedean or normal straight-profile right-handed worm gear with a large working worm indexing cylindrical lead angle γ, the angle δ between the inclined flat plane 73 of the flying cutter straight shank and the flying cutter zero rake angle front cutting edge 75 is equal to the working worm indexing cylindrical lead angle γ, and the flying cutter zero rake angle front cutting edge 75 is exactly in the normal plane of the working worm. Since the flying cutter zero rake angle front cutting edge 75 is clamped in the normal direction, the cutting edges on both sides of the flying cutter have reasonable front and back angles, which can improve cutting conditions and improve quality and work efficiency.

[0108] By adopting this technical solution, the angle δ between the flying cutter straight shank beveled flat plane 73 and the flying cutter zero rake angle front cutting surface 75 and the angle θ between the flying cutter straight shank 72 and the axis line of the flying cutter straight shank 72 of the present invention is independent of each other, and only affects the accuracy of the contact surface between the opposite end beveled end surface 51 of the positioning push rod and the flying cutter straight shank beveled flat plane 73, that is, the influence of the processing error of the θ angle on the δ angle is avoided, so there is no principle error of the angle δ between the flying cutter zero rake angle front cutting surface 75 and the rotation center line of the tool rod 1, and the azimuth angle (angle δ) of the flying cutter zero rake angle front cutting surface 75 on the tool rod 1 is one of the conditions for the correct use of the flying cutter, so the flying cutter and the tool rod are properly designed, which creates conditions for correct use, while the existing technology is related to the inclination angle β of the beveled plane set on the cylindrical part of the round pull rod (see Figure 3 ).

[0109] By utilizing the double superimposed force application (increase) of the inclined wedge (the inclined surface of the positioning push rod) and the tightening screw 10, double self-locking and the force application (increase) and self-locking of the square cylindrical end screw (force-applying component) 6, the elastic push rod 13 is used to solve the interference problem of the clamping of the two flying cutters 7. Through the above measures, positioning, double clamping and triple self-locking are achieved at the same time; it fully meets the requirements that the two flying cutters 7 are reliably clamped after being installed in the tool rod 1, and do not move or rotate during strong cutting, and has high connection stiffness and reliability; it is a commonly used and reliable force-increasing self-locking mechanism.

[0110] The present invention does not involve other parts of the tool rod, which are set up in a conventional manner; because the present invention avoids the influence of the processing error of the angle θ on the angle δ, ordinary technicians in this field can make adaptive changes to the flying cutter, such as a screw hole provided on the axis line of the flying cutter straight handle 72, a waist-shaped hole provided on the oblique flat surface 73 of the straight handle of the first flying cutter 7A along the axis of the flying cutter, and the blades on both sides of the flying cutter are symmetrical with respect to the axis line of the flying cutter straight handle 72, etc. The other settings of the flying cutter are conventional.

[0111] As a reminder, the front cutting surface of the teeth (fly cutter) of the shank worm gear tool is directional because the active end of its tapered shank is fixed to one end of the tool, and the rolling cutting motion relationship of the specific machine tool is unchanged. The sleeve worm gear tool can be turned around and installed in the tool arbor to change it. This is the fundamental difference from the sleeve worm gear tool.

[0112] The main clamping procedures of the flying cutter are as follows:

[0113] 1) Based on the distance from the fly cutter's tooth thickness on the working worm indexing cylinder to the fly cutter head positioning plane 71, and from the plane 21 to the rotation centerline of the cutter bar, select an open washer 3 of appropriate thickness and install it into the fly cutter shank 72. The positioning and clamping components are sequentially placed in the center hole 4. At the same time, the fly cutter shank 72 is inserted into the corresponding connecting through hole 2 from the side engraved with the orientation mark. In this way, the two fly cutter cutting edges extend out of the cutter bar in the same direction, and the fly cutter's zero rake angle rake face 75 faces the direction of rotation when the fly cutter is working.

[0114] 2) At this time, the flat plane 73 of the straight handle of the flying cutter is facing the passive end surface 11 of the cutter bar, ensuring that a close surface contact is formed between the positioning plane 71 of the flying cutter head and the open washer 3 and the plane 21, and the positioning clamping mechanism 8 applies appropriate force;

[0115] 3) Depending on whether there is a stepped hole, tighten the tensioning screw 10 with or without the flat washer 9 appropriately. Measure online with the help of a precision measuring instrument. When the tooth thickness of the fly cutter is exactly on the indexing cylinder of the working worm, position the clamping mechanism 8 and clamp it. Then further tighten the tensioning screw 10, and apply force alternately until the fly cutter 7 is clamped.

[0116] 4) When the fly cutter (set) is replaced or the hobbing cutter is worn and then reground after a period of time, repeat the above process.

[0117] The above working process respectively determines the correct position of the tooth thickness of the two flying cutters 7 on the working worm indexing cylinder in the radial direction of the cutter bar 1 and the orientation of the flying cutter zero rake angle rake surface 75.

[0118] Implementation Method 2

[0119] Figure 5 It reflects the specific structure of another embodiment of the present invention. The difference between this embodiment and Example 1 is that the force-applying member 6 is an electro-hydraulic push rod or a liquid or pneumatic cylinder, or a gas-liquid force-amplifying mechanism and is positioned and connected with the tool rod 1; specifically, the larger diameter part of the center hole 4 (entrance end) is a circular light hole 42 to facilitate the sliding positioning of the force-applying member 6, and a plurality of screw holes connected to the force-applying member 6 are provided on the passive end face 11, and the rolled worm gear is left-handed.

[0120] A further technical solution is: the force-applying component 6 adopts an electro-hydraulic push rod or a liquid or pneumatic cylinder, or a gas-liquid force-amplifying mechanism, which uses liquid, air pressure or electricity as energy to generate axial force, and uses the piston rod of the hydraulic cylinder or pneumatic cylinder as the force-applying terminal 61. The rotation center line of the force-applying component 6 is provided with an interface 63 connected to electricity, liquid, or gas, such as a hydraulic or pneumatic control interface 63 that is a rotary joint.

[0121] When the hydraulic, pneumatic cylinder or electro-hydraulic push rod is working, the force-applying terminal 61 moves axially to generate axial force, and through the plurality of balls 12, the opposite end oblique end surfaces 51 of the first positioning push rod and the second positioning push rod slide simultaneously to the oblique flat surface 73 of the flying knife straight handle to form a close surface contact, so that the two flying knives 7 are fastened in the corresponding connecting through holes 2 and are in the correct position.

[0122] A further technical solution is that the force-applying member 6 is slidably positioned with the central hole 4 and connected to the passive end face 11 of the tool rod.

[0123] Implementation 3

[0124] Figure 6 This embodiment reflects the specific structure of another embodiment of the present invention. The difference between this embodiment and Example 2 is that the force member 6 is δ=0°. Specifically, the force member 6 is a spring or a spring assembly. Figure 6 Shown in the center hole 4 are the disc spring and the adjusting flat washer.

[0125] A further technical solution is that the force-applying member 6 adopts a spring or a spring assembly, which is uniformly elastically deformed after being compressed, and the elastic force generates an axial force to push the force-applying terminal 61 to move axially, and the elastic force is adjusted by adjusting a flat washer or a screw.

[0126] When the spring is compressed and uniformly deformed, the force-applying terminal 61 moves axially to generate axial force, and through the plurality of balls 12, the opposite oblique end surfaces 51 of the first positioning push rod and the second positioning push rod slide simultaneously to the oblique flat surface 73 of the flying knife straight handle to form a close surface contact, so that the two flying knives 7 are fastened in the corresponding connecting through holes 2 and are in the correct position.

[0127] The adjusting flat washer can also be arranged between the force applying member 6 and the passive end face 11 of the knife bar (not shown separately). In order to facilitate the screwing to generate compression force on the spring, the screw is arranged on the center line of the force applying member 6 and the passive end face 11 of the knife bar (not shown separately).

[0128] Generally, the front angle of the flying cutter is 0°. At this time, the flying cutter front cutting surface 75 coincides with the axis of the flying cutter straight handle 72, and has front and back angles suitable for cutting. When the flying cutter 7 is clamped on the tool rod 1, the flying cutter zero front cutting surface 75 is just in the axial plane of the working worm, that is, it coincides with the rotation center line of the tool rod 1, so that the cutting edge part of the flying cutter head 74 is in the same position as the working worm, that is, the flying cutter zero front cutting surface 75 coincides with the rotation center line of the tool rod 1 (that is, the angle is 0°).

[0129] A further technical solution is: the angle δ between the inclined flat plane 73 of the straight shank of the flying cutter and the zero-rake angle front cutting edge 75 of the flying cutter should be such that when the flying cutter 7 is clamped on the tool rod 1, the zero-rake angle front cutting edge 75 of the flying cutter is exactly in the axial plane of the working worm, that is, δ = 0°, according to the type of working worm, the precision grade, the size of the working worm indexing cylindrical lead angle and the direction of rotation.

[0130] For example, when rolling an Archimedean gear with a smaller cylindrical lead angle γ of the working worm and a normal straight-profile worm gear with low precision requirements, the angle δ between the beveled flat plane 73 of the flying cutter straight shank and the flying cutter zero-rake angle front cutting edge 75 is equal to 0°, and the flying cutter zero-rake angle front cutting edge 75 is just in the axial plane of the working worm. Since the flying cutter zero-rake angle front cutting edge 75 is clamped axially, the cutting angles of the cutting edges on both sides are different, such as the sharp edge has a positive rake angle and the blunt edge has a negative rake angle, etc., the cutting conditions are inconsistent, and vibration ripples are easily generated on the tooth surface of the cut worm gear, which limits the improvement of productivity and the performance of the machine tool and the tool cannot be brought into play. In order to improve the cutting conditions, a special grinding method can be used to grind the front cutting edge so that the cutting edges on both sides of the flying cutter have a suitable rake angle.

[0131] Implementation 4

[0132] Figure 7It reflects the specific structure of another embodiment of the present invention (only the features of Example 1 are used for illustration). The difference between this embodiment and the above embodiments is that the opening direction of the acute angle θ is opposite to them, that is, the opening direction of the acute angle θ is toward the flying knife straight handle 72, and the connecting through hole 2 is a stepped hole, and no flat washer 9 is provided. At this time, the supporting surface of the tightening screw 10 is directly placed on the plane 21, which is equivalent to the flat washer 9 being integrated into the tool rod 1 and becoming one. At this time, the small hole of the stepped hole is the hole of the flat washer 9, and the rest is the same; similarly, the inclination angle of the oblique end faces 51 of the opposite ends of the first positioning push rod 5A and the second positioning push rod 5B is equal to the acute angle θ of the oblique flat plane of the flying knife straight handle. Those skilled in the art know that although there is an inclined surface here, the tightening screw 10 generates a force and intermittent cutting force against the flying cutter head 74, which does not meet the conditions of inclined wedge force amplification and self-locking. The intermittent cutting force will not have a direct impact on the positioning clamping mechanism 8. When the flying cutter 7 is clamped along its axial direction, only the spiral clamping force amplification and self-locking of the tightening screw 10 are used. The tension generated by the tightening screw 10 is more than dozens of times the applied force, generating a large clamping force. Therefore, when the flying cutter 7 is clamped along its axial direction, the force generated by the tightening screw 10 is generated when the tightening screw 10 is tightened. That is to say, in this embodiment, under the combined action of the force generated by the tightening screw 10 and the force-applying member 6, the two flying cutters 7 are fastened in the corresponding connecting through-holes 2 through a plurality of the balls 12. This embodiment takes a two-stage stepped hole as an example. The omission of the flat washer 9 simplifies the structure and facilitates tool management.

[0133] At this time, under the action of the axial clamping force and cutting force along the tool rod 1, the flying cutter 7 generates a force toward the center of the tool rod 1, and the flying cutter 7 tends to move toward the center of the tool rod 1. Under the action of the tightening screw 10, the flying cutter head positioning plane 71 further compacts the opening gasket 3 on the plane 21 to improve the repeat positioning accuracy. The flying cutter 7 will not move or rotate, the dynamic stiffness between the tool and the tool rod is better, and better positioning and clamping performance is obtained, which is a better implementation method.

[0134] Implementation 5

[0135] Figure 8This embodiment reflects the specific structure of another embodiment of the present invention (illustrated only with reference to the features of Example 1), and can be considered a special case of Examples 1, 2, 3, and 4. This embodiment differs from these embodiments in that the angle θ between the obliquely cut flat surface 73 of the fly cutter shank and the axis of the fly cutter shank 72 is 0°, while all other aspects remain the same. In this case, the angle of inclination of the oblique end surfaces of the opposing ends of the first positioning push rod 5A and the second positioning push rod 5B is 0°. Clearly, there is no wedge force amplification or self-locking, only the spiral clamping force amplification and self-locking of the tensioning screw 10. Therefore, the axial clamping of the fly cutter 7 is generated by the force generated by tightening the tensioning screw 10. In other words, in this embodiment, the two fly cutters 7 are secured within the corresponding connecting through-holes 2 via the plurality of balls 12, under the combined force of the tensioning screw 10 and the force-applying member 6.

[0136] At this time, under the action of the axial clamping force along the tool rod 1, no force will be generated to cause the flying cutter 7 to move away from or toward the center of the tool rod 1. Under the combined action of the tightening screw 10 and the cutting force toward the center of the tool rod 1, the flying cutter 7 tends to move toward the center of the tool rod 1, so that the flying cutter head positioning plane 71 further compacts the open gasket 3 on the plane 21 to improve the repeat positioning accuracy. The flying cutter 7 will not move or rotate, and the dynamic stiffness between the tool and the tool rod is better, thereby obtaining better positioning and clamping performance, which is a better implementation method.

[0137] The differences in cutting force and arbor diameter, material strength, working worm type, working worm indexing cylindrical lead angle and accuracy, and manufacturing convenience can be comprehensively considered. In order to ensure better clamping and self-locking effects and economy, the above five embodiments can be selected or combined.

[0138] The angle between the oblique flat plane of the flying cutter straight shank and the axis of the flying cutter straight shank is an acute angle θ or 0°. Since the tightening screw and the open washer combine to form a threaded pair connection mechanism with fine adjustment, clamping and self-locking properties, and are measured online with the aid of a measuring instrument, since the acute angle θ is small, no matter which direction the opening of the acute angle θ is facing or is 0°, or no matter how large the external (resistance) force is, even without the force increase and self-locking of the inclined wedge, the flying cutter will not move or rotate, and will be guaranteed to be in the correct position to meet the working conditions.

[0139] Through the above measures, combined with the existing manufacturing technology, the accuracy and consistency of the production of the flying cutter and the tool rod can be guaranteed. The present invention better realizes the proper design and correct use of the flying cutter and the tool rod. Since the flying cutter has a simple structure and is mostly single-tooth, it is more convenient to manufacture, sharpen and detect. High-precision, high-performance and high-hardness flying cutters are easier to obtain than worm hobs. Since the number of broken line segments that envelop the worm gear tooth profile is inversely proportional to the size of the tangential feed, and the productivity is directly proportional to it, the tooth profile accuracy (contact spots) can be manually controlled during the tooth cutting process, and the productivity is improved compared to the existing technology, and the accuracy is higher than the accuracy of processing with a worm hob, especially in the case of a small diameter of the worm hob for the rolling cutting work, the accuracy is higher, and a multi-head, large-module and small-tooth worm gear has more advantages.

[0140] However, those skilled in the art should understand that the force applying member 6 is not limited to Figures 4 to 8 The specific structural form shown, for example, the spring can be a truncated cone helical compression spring or a truncated cone scroll spring, or even a rubber spring, etc. In addition, the center hole 4 is not limited to being formed as a circular hole cavity and a hole with three steps, it can also be formed as a square hole cavity, such as a square hole, or a hole with two steps, etc. Of course, in this case, the shapes of the positioning push rod 5 and the force member 6 are correspondingly modified or changed, and the positioning and connection methods of the force member 6 are adaptively changed.

[0141] The preferred embodiment of the present invention has been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiment. Within the scope of the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all fall within the scope of protection of the present invention. For example, if the distance from the top edge of the fly cutter 7 to the outer circle of the tool bar 1 is determined by measurement, then the opening washer 3 can be omitted, or the corresponding end plane 21 can also be omitted. For example, to reduce the number of tool bars, there can be more than two connecting through holes 2, but only two fly cutters 7 can be installed, or the center distance between adjacent connecting through holes 2 is not equal to an integer multiple of 1 of the axial pitch of the working worm. In addition, even if only one fly cutter is installed and the opening direction of the acute angle θ of the fly cutters used simultaneously is opposite, this does not affect the realization of the purpose of the present invention.

[0142] It should also be noted that the various technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0143] The above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention, and the scope of patent protection of the present invention should be defined by the claims.

Claims

1. A double vertical clamping structure of a double worm gear flying cutter, comprising a cutter bar (1) and a flying cutter (7), wherein the flying cutter (7) comprises a first flying cutter (7A) and a second flying cutter (7B), characterized in that The tool rod (1) is composed of an active end with a tapered shank and an elongated passive end, the passive end is provided with a center hole (4) facing the active end and concentric with the rotation center line of the tool rod (1), two parallel connecting through holes (2) for installing and tightening the flying cutter (7) are radially provided in the middle of the tool rod (1) along the rotation center line of the tool rod, the center distance between the connecting through holes (2) is the axial tooth pitch of a working worm gear πm, and the two straight-view ends of the connecting through holes (2) are provided with planes (21), wherein the planes (21) on the same side of the rotation center line of the tool rod (1) are provided with tightening screws ( 10), and connected with the screw hole provided on the axis line of the flying knife straight handle (72), the center line of the connecting through hole (2) is perpendicular and passes through the rotation center line of the knife rod (1), and is connected with the center hole (4), the positioning clamping mechanism (8) is arranged in the center hole (4), and a force-applying member (6), a plurality of balls (12), a first positioning push rod (5A), a first flying knife (7A), an elastic push rod (13), a second positioning push rod (5B), and a second flying knife (7B) are sequentially arranged inward from the passive end face (11), wherein the elastic push rod (13) passes through the first flying knife (7A) ), the elastic push rod (13) is a composite component provided with a ball, an adjusting flat washer and a spring, and the cylindrical end of the elastic push rod (13) is inserted into the concentric positioning blind hole (53) at one end of the inclined end surface (51) of the first positioning push rod (5A), and the corresponding end of the second positioning push rod (5B) is a ball, the angle between the inclined flat plane (73) of the straight handle of the flying knife and the axis line of the straight handle (72) of the flying knife is an acute angle θ or 0°, and the value range of the acute angle θ is between 3° and 6°, and between the tension screw (10) and Under the joint action of the force generated by the force-applying member (6), the oblique end surfaces (51) of the opposite ends of the first positioning push rod (5A) and the second positioning push rod (5B) simultaneously slide onto the oblique flat surface (73) of the straight shank of the flying cutter to form a close surface contact, and the flying cutter (7) is fastened in the corresponding connecting through hole (2), and the cutting edge portion of the flying cutter head (74) is located at the same position as the working worm, and the cutting edge portion of the flying cutter head (74) extends out of the tool rod (1) in the same direction as the zero rake angle front face (75) of the flying cutter faces the rotation direction of the flying cutter when it is working; The connecting through hole (2) has the same size and shape, wherein the distance from the plane (21) on one side of the flying knife straight handle (72) to the rotation center line of the knife rod (1) is consistent, and the distance dimension value and the flying knife (7) installation orientation are engraved and marked, an open washer (3) is provided between the plane (21) and the flying knife head positioning plane (71), and a flat washer (9) is provided or not provided between the plane (21) on the other side and the tightening screw (10), and the plane (21) is perpendicular to the center line of the connecting through hole (2); The inclination angle of the oblique end surfaces (51) at the opposite ends of the first positioning push rod (5A) and the second positioning push rod (5B) is equal to the acute angle θ of the oblique flat plane (73) of the straight handle of the flying knife, or the inclination angle of the oblique end surfaces (51) at the opposite ends of the first positioning push rod (5A) and the second positioning push rod (5B) is 0°; The included angle δ between the straight shank beveled flat plane (73) of the flying cutter and the zero rake angle front cutting surface (75) of the flying cutter is equal to the working worm indexing cylinder lead angle γ, or the included angle δ between the straight shank beveled flat plane (73) of the flying cutter and the zero rake angle front cutting surface (75) of the flying cutter is 0°.

2. The double vertical clamping structure of the double worm gear flying cutter according to claim 1 is characterized in that The connecting through hole (2) is a round hole, a square hole or a stepped hole, and the connecting through hole (2) and the positioning part of the flying knife straight handle (72) are straight holes.

3. The double vertical clamping structure of the double worm gear flying cutter according to claim 1 is characterized in that The force-applying member (6) adopts a screw with a square cylindrical end, and an axial force is generated when the screw is tightened. The force-applying terminal (61) of the force-applying member (6) and the threaded part (62) of the force-applying member (6) that generates force are integrated; or, the force-applying member (6) adopts an electro-hydraulic push rod or a liquid or pneumatic cylinder, or a gas-liquid force-increasing mechanism, and the axial force is generated by liquid, gas pressure or electricity as energy, and the piston rod of the hydraulic cylinder or the pneumatic cylinder is used as the force-applying terminal (61). An interface (63) connected to electricity, liquid or gas is provided on the rotation center line of the force-applying member (6); or, the force-applying member (6) adopts a spring assembly, and the spring is uniformly elastically deformed after being compressed by force, and the elastic force generates an axial force, which pushes the force-applying terminal (61) to move axially, and the elastic force is adjusted by adjusting a flat washer or a screw.

4. The double vertical clamping structure of the double worm gear flying cutter according to claim 1 is characterized in that The force-applying member (6) is positioned and connected to the center hole (4), or the force-applying member (6) is slidably positioned with the center hole (4) and connected to the passive end face (11) of the knife rod.

5. The double vertical clamping structure of the double worm gear flying cutter according to claim 1 is characterized in that The positioning clamping mechanism (8) is lubricated by lubricating wax, calcium-based grease, molybdenum disulfide or thin oil.

Images