62results about "Broaching tools" patented technology

The invention provides an efficient broach grinding machine with double grinding wheels for collaborative grinding, and belongs to the technical field of broach grinding machines. The problem that a broach grinding machine in the prior art is insufficient in flexibility is solved. The machine tool comprises a machine tool body, an X-axis assembly, a Y-axis assembly and a Z-axis assembly, the X-axis assembly, the Y-axis assembly and the Z-axis assembly are installed in the machine tool body, an upper driving box is installed at the upper end of an X-axis sliding block, an upper workbench is installed at the upper end of the upper driving box and is in driving connection with the interior of the upper driving box, a clamp groove is formed in the upper workbench, and a driving clamp and a driven clamp are connected in the clamp groove; the upper bearing box assembly is installed on one side of the upper end of the upper workbench, the chuck driving motor is installed at the upper end of the upper bearing box assembly and is in driving connection with the interior of the upper bearing box assembly, the chuck cylinder is connected with the chuck base and installed on one side of the upper bearing box assembly, and the interior of the chuck cylinder and the interior of the chuck base are in driving connection with the upper bearing box assembly. The broaching tool supporting device has the advantages of being stable in broaching tool supporting and capable of adapting to multi-size broaching tools.

The utility model discloses a broach with a special tooth embedded blade, which solves the problems that the service life of the existing broach is short due to the fact that the special tooth is easy to abrade in the broaching process to cause meat falling and strain at an outlet, and the existing broach is lack of special structural design in the radial direction and is not capable of improving the performance of individual teeth. The cutter comprises a cylindrical cutter body, a cutter strip groove is formed in the outer wall of the cutter body in the direction parallel to the central axis, a cutter strip is arranged in the cutter strip groove and connected to the cutter body through a bolt, and a plurality of special key grooves are formed in the cutter strip at equal intervals to form special teeth. The cutter further comprises a plurality of rows of spline cutting teeth, each row of spline cutting teeth is arranged on the outer wall of the cutter body, and the two ends of each row of spline cutting teeth are located on the two sides of the corresponding cutter strip groove respectively. A plurality of splines are arranged on each row of spline cutting teeth at equal intervals to form the spline cutting teeth; the broach is an assembly type broach, the blade can be replaced according to the actual use condition, and the economic cost is reduced.

A broach device for simultaneously machining a plurality of arc grooves in the outer surface of a workpiece comprises a tool apron which is of a disc-shaped structure, and a cylindrical mounting hole used for containing and positioning a tool is formed in the center of the tool apron; the broaching tools are evenly distributed in the circumferential direction of the tool apron, and each broaching tool comprises a tool body used for installation and positioning; the shape of the tooth part is composed of a section of arc and two oblique lines tangent to the arc, and the radius of the arc is smaller than that of the outer circle of the workpiece; and the plurality of screws are used for fixing the broaching tool in the positioning groove of the tool apron through the screw holes in the tool body.

The utility model relates to the technical field of broaching tools and provides a heavy-load broaching tool assembly which comprises a broaching tool box and a broaching tool arranged on the broaching tool box, an inserting hole is formed in the back face of the broaching tool box, a first hanging column is arranged on the first side face of the broaching tool box, and a second hanging column is arranged on the second side face of the broaching tool box. According to the heavy-load broach assembly, a complex grabbing clamp does not need to be adopted for fixing the broach box to carry out operations such as feeding, feeding and discharging of broaches any more, so that the operations such as loading, taking and placing of the heavy-load broach assembly are very convenient and fast, and the heavy-load broach assembly is convenient to use. The broach box can be conveniently and rapidly fixed in the using process of the heavy-load broach assembly.

A broach (20) or broach segment (20) has a spine (22). A longitudinal array of teeth (40-1...40-n) protrude from the spine (22), each said tooth (40-1...40-n) having: a first face and an opposite second face; and a distal surface joining the first face and second face; and at least some of the teeth (40-1...40-n) being firtree teeth (40-1...40-n) and have a peripheral trench adjacent the cutting edge of the at least one tooth (40-1...40-n).

The broach mechanism for the long-span main shaft comprises a main shaft body, the surface of a pull rod is movably connected with a pull rod sliding sleeve in a sleeved mode, a sealing ring is installed on the surface of one side of the pull rod sliding sleeve in an embedded mode, the outer side of the pull rod sliding sleeve is connected with a sliding sleeve fixing block, and the sliding sleeve fixing block is fixedly connected with the main shaft body. A hexagonal groove hole is fixedly formed in the surface of one side of the sliding sleeve fixing block, four sets of rear bearings and four sets of front bearings are installed on the inner side of the main shaft body, a front bearing seat is fixedly installed on one side of each front bearing, movement of a pull rod is separated from rotation of a rotor assembly, the complexity of the pull rod is reduced, and the service life of the pull rod is prolonged. And the number of structural parts is reduced. The fixing of the pull rod sliding sleeve can effectively reduce vibration and noise caused by too many degrees of freedom of the pull rod, the front bearing and the rear bearing are used at the front end of the main shaft body, through the paired use of the bearings, the axis positioning of the rotor assembly during high-speed rotation can be kept, and vibration and deviation are reduced.

This invention provides a broaching tool structure with complementary irregular cutting edges, including a tool holder, a precision adjustment component, a tool holder, and broaching inserts. The bottom of a guide rail is fixed to the tool holder, and the top of the guide rail has a groove that slides with a slide block. The tool holder is fixed to the slide block. Below the groove, the guide rail has an adjustment groove. A first wedge and a second wedge are positioned within the adjustment groove, their inclined surfaces engaging. The guide rail has an adjustment hole. A cylindrical boss is located on the outer surface of the first wedge, passing through the adjustment hole. A coarse adjustment sleeve is axially positioned within the adjustment hole and threaded onto the boss. A fine adjustment screw is axially positioned inside the boss and threaded to the outer surface of the first wedge. The second wedge is connected to the bottom of the slide block. An elastic reset element is positioned between the first or second wedge and the adjustment groove. This invention solves the problems of existing broaching tool cutting edge positions being unadjustable or having low adjustment resolution.

The application discloses a super-long internal broach for long-ratio inner hole profile broaching, which comprises a broach bar, a broach disc, a broach handle and a broach holder. The broach disc is detachably arranged on the broach handle. One end of the broach holder is detachably arranged on the broach handle and is positioned and connected with the broach disc. The other end of the broach holder is detachably connected with one end of the broach bar. The other side of the broach bar is detachably arranged on a machine tool. The application solves the problems of single broach manufacturing difficulty, multi-broach tool changing inconvenience, high manufacturing cost and high labor intensity when the conventional internal broach is used to broach a large aperture and a long-ratio hole with a ratio greater than 5 times. When the aperture is greater than 100 mm and the long-ratio is greater than 25 times, the application solves the bottleneck problem of being unable to manufacture. The broaching part and the non-broaching part are separated. The working part and the non-working part are clamped and loosened by hydraulic pressure. There is no pipeline winding, and the disassembly and assembly are convenient, and the labor intensity of workers is low.

The utility model discloses a high-precision numerical control broaching edge grinding machine, and relates to the technical field of broaching edge grinding machines. Comprising a grinding machine base, a machining mechanism used for the high-precision numerical control broaching edge grinding machine is arranged on the grinding machine base, the machining mechanism comprises a machining assembly, and the machining assembly comprises a supporting platform fixed to the upper end face of the grinding machine base. The grinding wheel and the broach are prevented from being damaged due to overheating, meanwhile, the spraying of the water source can play a role in lubrication, friction between the grinding wheel and the broach is reduced, grinding efficiency and quality are improved, grinding precision and surface quality are improved, and chippings in air are effectively reduced, so that the working environment is improved, and harm of dust to health of operators is reduced. A water source containing waste chips directly flows into the water collecting shell through the through holes to be collected, and the waste chips and sewage can be rapidly cleaned away.

The application discloses a kind of cutting performance prediction methods of flocking broach.The method includes the following steps: one, the effective contact length of the tested broach in cutting process is obtained.Two, the transduction coefficient for evaluating the heat dissipation capacity of the tested broach is obtained.Three, the broaching performance of the tested broach is judged.The application considers the various parameters of broach rake face flocking and the factor parameters of lubricating fluid, constructs the temperature field mathematical model of flocking broach, and realizes the accurate evaluation of temperature field in the cutting process of flocking broach through transduction coefficient.The application can accurately obtain the effective contact length and transduction coefficient of flocking broach by constructing two mathematical models, and evaluate the cutting performance of flocking broach and provide corresponding optimization scheme for flocking broach.The broaching tool designed for the size of horizontal broaching machine integrated broach realizes the effects of optimizing and reforming traditional broach, convenient disassembly and assembly and replacing single-tooth broach.

The invention belongs to the technical field of broaching equipment, and discloses a broach facilitating workpiece positioning and a positioning method thereof.The broach comprises a broach body, broach teeth distributed on the broach body in an array mode and a guide handle, an adaptive side groove is formed in the side face of the broach body, and a self-positioning assembly is elastically connected into the adaptive side groove in a sleeved mode; the bottom of the cutter body is elastically connected with an adjustable positioning mechanism, one end of the adjustable positioning mechanism is fixedly connected with a guide handle, and a hydraulic control mechanism is arranged in the guide handle. The self-positioning assembly which is elastically connected and arranged on the side face of the tool body is matched with a clamp to conduct intermittent clamping during machining and sleeving, so that a workpiece is in self-adaptive broach sleeving, automatic elastic calibration is conducted after sleeving, automatic positioning is completed, transverse deviation in a machining area is avoided, the actual pulling machining precision is greatly improved, and the machining efficiency is improved. Positioning operation is simple, and the using effect is good.

The present invention discloses a broaching device for an arc-shaped tenon groove, which relates to the field of mechanical processing. The device comprises a broaching disc, a turbine disc drive mechanism, and a turbine disc clamping mechanism. The broaching disc is connected to the broaching disc drive mechanism. The broaching disc comprises a broaching disc base and a sliding broaching tool holder. The surface of the broaching disc base is provided with multiple linear guides, and a lead screw is installed in the linear guide. One end of the lead screw is connected to the broaching tool drive mechanism. The sliding broaching tool holder is threadedly engaged with the lead screw, and one or more broaches are mounted on the sliding broaching tool holder. The turbine disc drive mechanism comprises a turbine disc rotating mechanism and a turbine disc telescopic mechanism. The turbine disc is mounted on the turbine disc rotating mechanism, and the turbine disc rotating mechanism is connected to the turbine disc telescopic mechanism. The turbine disc clamping mechanism comprises a bidirectional slide rail structure, and the turbine disc telescopic mechanism is fixed to the bidirectional slide rail structure. The present invention can accurately machine an arc-shaped tenon groove that matches the arc radius of the tenon groove, thereby improving processing efficiency and quality.

An automatic groove broaching device for tool pliers comprises tooth groove cutting dies which are linearly and fixedly arranged, the tooth groove cutting dies comprise a fixed tooth cutting die, a single variable cutting die and a double variable cutting die, the single variable cutting die is arranged at the lower end of the fixed tooth cutting die, the double variable cutting die is arranged at the lower end of the single variable cutting die, and the shape of the cross section of the fixed tooth cutting die is kept constant; the height of the cross section of the single variable cutting die is constant, the width of the cross section is gradually reduced in the length direction, the height and the width of the cross section of the double variable cutting die are gradually reduced in the length direction, and oil nozzles are arranged in the tooth groove cutting die at intervals. The cross section of the tooth groove cutting die is designed to be gradually changed, cutting resistance can be reduced and cutting scrap iron can be reduced by gradually increasing the feeding amount when a jaw is cut through groove broaching, and the oil spray nozzle can coat lubricating oil on the tooth face of the jaw in the groove broaching operation process, improve groove broaching smoothness and solve the problems that the tooth face is rough, passivated and the like.

The application relates to the field of metal cutting, in particular to a broaching machine and a broaching method thereof. The broaching machine comprises outer surface broaches, the outer surface broaches are provided with a plurality of outer surface broaching teeth, the right part of the lower side of the outer surface broach is uniformly provided with a plurality of broaching teeth, the heights of the plurality of broaching teeth increase from left to right in sequence, the left part of the outer surface broach is provided with a plug hole, the plurality of outer surface broaches are arranged in front and back sticking mode, and a plug rod simultaneously penetrates through the plurality of plug holes. The broaching machine further comprises a door-shaped piece, the door-shaped piece is provided with a limiting groove, the left end of the plurality of outer surface broaches is inserted into the limiting groove, the front and back two ends of the plug rod are respectively inserted into the front and back two sides of the door-shaped piece, and the front and back two ends of the plug rod are all screw-connected with blocking heads. The width of the broach can be adjusted.

The invention relates to the field of gearbox part machining, and discloses a gearbox input shaft machining method which comprises the steps that a spline inner hole is machined in an input shaft blank before heat treatment, an internal spline is machined after heat treatment, then the internal spline is adopted for positioning, and center holes in the two axial ends of the input shaft blank and a journal outer circle are machined. A spline inner hole is machined before heat treatment, and an internal spline is machined after treatment, so that the small diameter of the internal spline and the pitch circle of the internal spline are used as the consent machining reference, the internal spline is used as the machining reference for positioning and machining center holes in the two axial ends of the gearbox input shaft, and the machining reference of the pitch circle of the internal spline and the machining reference of the outer circle of a shaft neck are kept uniform; the central holes in the two axial ends of the input shaft of the gearbox are used for positioning and machining the outer circle of the journal, reference conversion is achieved, the technical precision of the pitch circle of the internal spline and the outer circle of the journal is guaranteed, and the machining precision of the input shaft of the gearbox is improved. The invention further provides the gearbox input shaft and a gearbox assembly.

The invention relates to the technical field of broach grinding machines, in particular to a seven-axis linkage device for a numerical control broach grinding machine, a supporting seat body is further arranged on a control rail, and the supporting seat body is positioned through an arranged regulation and control positioning assembly; the auxiliary mechanism is used for conducting auxiliary supporting on the broach workpiece. Limiting is carried out through matched use of the driving tip and the rotating tip, and on the basis of limiting, flexible support is provided for a broach workpiece through matched use of the arranged supporting seat body and the auxiliary mechanism, so that the influence caused by vibration in the machining process is avoided; when the broach workpiece is rotated, the broach teeth of the broach workpiece are prevented from being scratched and damaged; the method is achieved through cooperative use of the arranged auxiliary roller and the flexible assembly. Besides, a positioning effect is provided for the supporting seat body through the arranged regulating and positioning assembly, the supporting seat body is slidably adjusted on the control rail according to actual machining requirements, and after the supporting seat body is adjusted to a proper position, the position of the supporting seat body is positioned.

The invention belongs to the technical field of machining equipment, and particularly relates to a broaching machine which comprises a machine body, a hydraulic cylinder is arranged at the tail end of the machine body, a tool rest groove is formed in the machine body, and a limiting hole and a workpiece mounting opening are formed in the front end of the machine body. The main tool rest is movably arranged in the tool rest groove and is driven by a hydraulic cylinder to move in the front-back direction of the lathe body; the guide rods are arranged in the tool rest groove, the two guide rods are symmetrically distributed in the left-right direction of the lathe body, and the guide rods are used for limiting the moving direction of the main tool rest; the broach is pulled by the main tool rest to cut the workpiece; the auxiliary mechanism is arranged on the front side of the lathe body and comprises a bracket used for supporting the broach during the return stroke of the broach; the damping mechanism is arranged on the bed body and located in the middle of the bed body in the front-back direction, and the damping mechanism comprises a guide roller with lifting damping in the vertical direction. Compared with the prior art, the working efficiency and the workpiece cutting quality are improved.

This invention discloses a tenon and grooving broach and its atomizing cooling structure. Addressing the technical problem in existing technologies where coolant struggles to penetrate the narrow gap between the broach head and the workpiece, the invention incorporates a main coolant channel, a main compressed gas channel, coolant branch channels, compressed gas branch channels, and a compressed gas loop within the broach body. Each coolant branch channel includes a gas-liquid mixing chamber with an inverted cone and a fan-shaped slit outlet at its top, forming a nozzle structure. Each compressed gas loop contains multiple inclined injection channels for injecting compressed gas into the gas-liquid mixing chamber. During operation, the coolant and compressed gas mix and atomize in the gas-liquid mixing chamber, forming finer, higher-pressure atomized particles that are projected onto the broach head surface through the nozzles, achieving effective cooling of the broach head. Through this atomizing cooling structure, this invention effectively reduces the operating temperature of the tenon and grooving broach, extends its lifespan, and improves machining quality and surface integrity.

The utility model provides an improved broaching tool which comprises a broaching tool body. The positioning structure is arranged on the broach body and comprises a front positioning part and a rear positioning part; the optimized tooth profile is formed on the broach body, and the optimized tooth profile has an optimized tooth profile angle; and the grinding wheel is matched with the broach body.

The invention relates to the related technical field of numerical control lathes, in particular to an air floating type tailstock structure for a numerical control broach grinding machine, which comprises guide rails, a sliding seat, a base, a tailstock main body and a telescopic electric cylinder, a connecting lug is integrally formed on the side edge of the sliding seat, and the connecting lug on the sliding seat is fixed to the lower surface of the base through a first-stage bolt. The upper air cavity and the first-stage mounting groove are formed in the sliding seat, and the first-stage air floating plate is mounted in the first-stage mounting groove, so that air is supplied to the upper air cavity through the first-stage air supply equipment and is supplied to the upper air cavity through the first-stage air floating micropores in the first-stage air floating plate, and a layer of air film is formed between the guide rail and the sliding seat through the air; therefore, the operation friction resistance of the sliding seat is effectively reduced, the mechanical abrasion of the guide rail and the sliding seat is effectively reduced, the service life of the structure is prolonged, and the movement flexibility of the sliding seat is improved.

This utility model discloses a quick-change fixture for a knife grinding machine, comprising: an integrated tool holder with an assembly groove on it, wherein a knife is installed at the bottom of the cavity of the assembly groove; a downward positioning mechanism mounted on the knife; a mounting plate fixedly mounted on one side of the integrated tool holder; a rotary propulsion mechanism inserted into the top of the mounting plate; and a pressing mechanism connected to one end of the rotary propulsion mechanism. This utility model utilizes the combined arrangement of the downward positioning mechanism and the pressing mechanism, and by optimizing the fit between the pin and the center hole of the diamond blade, eliminates assembly gaps, ensuring consistent clamping positions each time, significantly improving the uniformity of blade dimensions after grinding. The linkage design of the elbow clamp and the connecting mechanism allows the downward positioning mechanism to clamp or release the knife simply by lifting and rotating the elbow clamp, greatly shortening the clamping time.

The utility model discloses a kind of circular-arc blade of broach, including blade main body, the blade main body includes main cutting edge, positioning groove, locating surface and tool tooth, the main cutting edge is the circular-arc blade being set in tool tooth top, the tool tooth is evenly arranged along blade main body long side side, and both sides tool tooth is set with blade central axis as axis symmetry, axially extending chip flute is equipped between adjacent tool tooth, the locating surface one side is equipped with main cutting edge rake face, the main cutting edge rake face extends to tool tooth, and main cutting edge rake face and locating surface transition connection;The positioning groove is symmetrically set in blade main body short side side.The utility model's cutting edge is high in strength, not easy to wear, and the cutting life of blade is high, improves the cutting stability and processing efficiency of blade.

The present invention relates to the technical field of correction broaches and discloses a combined carbide fine broach, comprising a tool body, wherein the tool body is composed of a plurality of toothed knives and a plurality of annular knives, the blade portion of the toothed knives being adapted to the spline groove of the inner ring of the correction part, the annular blade of the annular knife being adapted to the spline inner ring surface of the inner ring of the correction part, and the plurality of toothed knives and annular knives being alternately distributed in sequence along the axial direction; the combined carbide fine broach, by designing alternately distributed toothed knives and annular knives, and in the movement direction of the fine broach, making the tooth portion sizes of the plurality of toothed knives distributed in sequence from large to small, and making the sizes of the plurality of annular knives distributed in sequence from large to small, can reduce the cutting amount of correction of each toothed knife and annular knife, can perform one-time correction processing on the correction part to improve the correction processing accuracy and efficiency of the correction part, and at the same time reduce the difficulty of feed and avoid damage to the correction part.

The invention belongs to the technical field of machining, and particularly relates to a method for accurately driving a target vibration mode of an ultrasonic broaching machine, which comprises the following steps of: S1, designing a band-pass filter, carrying out a frequency sweep test, determining an axial modal bandwidth and carrying out thermal drift compensation; s2, realizing a digital filter, and optimizing a transition zone by adopting a Kaiser Window (Kaiser Window); a filter coefficient is quantized into a 18-bit fixed-point number format, so that the calculation efficiency during hardware implementation is improved; the FPGA is used for accelerating the filter, and the FIR filter is designed and has a linear phase characteristic so as to ensure that the signal is not distorted due to the filtering process; a standby analog circuit design is designed to serve as a supplement of a digital filter, and more redundancy and stability are provided. The broach vibration mode can be accurately driven, the purity of axial vibration is remarkably improved, the radial vibration suppression ratio is increased, and the machining precision and stability of ultrasonic equipment are further improved.

The invention relates to a broach quick dismounting device applied to a machine tool, and belongs to the technical field of machine tool machining, the quick dismounting device structurally comprises a broach lathe, a quick dismounting mechanism is arranged on the broach lathe, a quick dismounting machine comprises a driving assembly, a quick dismounting assembly is arranged at one end of the driving assembly, and the quick dismounting assembly comprises an unlocking head; a hollow cavity is formed in the unlocking head, a receding groove is formed in the position, on the outer ring of the hollow cavity, of the unlocking head, a first sliding hole penetrating through the hollow cavity is formed in the unlocking head, an unlocking disc and multiple sets of balls are arranged in the hollow cavity, and multiple sets of unlocking holes are formed in the side wall of the hollow cavity in the circumferential direction. The multiple sets of balls are arranged in the multiple sets of unlocking holes in a sliding mode, the unlocking disc is arranged in the hollow cavity in a sliding mode and abuts against the balls, and the driving assembly is used for driving the unlocking disc to slide; the tool changing device has the technical effects that the tool changing efficiency is improved, and the tool is stably clamped.

The invention relates to a variable-shape groove broaching method capable of changing the depth of an inner hole and a machining tool, and belongs to the field of deep hole broaching machining. The cutter comprises a brush (1), a plug (2), a front guide sleeve (3), a spring (4), a compression screw (5), a broaching blade (6), a body (7), a rear guide sleeve (8), a cutter bar (9) and a mandrel (10), the connected broaching blade extends into a steel pipe along with the cutter bar (9) and the mandrel (10) under the driving of a spindle box (12) according to the length and depth size of a groove, the spindle box (12) drives the cutter bar (9) and the mandrel (10) to move towards the left end together, and the groove broaching blade (6) and the body (7) are pulled into the steel pipe. The method has the remarkable effects that the machining precision of the depth-variable large-width special-shaped long groove of the inner hole of the ultra-long steel pipe is greatly improved, and the tool consumption cost is reduced.

The utility model provides a chip collecting box of a broach and a notch broaching machine. The chip collecting box of the broach comprises a filter screen, a first box body, a plurality of second box bodies and a plurality of installation frames. The first box body is provided with an inner cavity, and a via hole for a broach to penetrate through is formed in the inner cavity. The second box bodies are attached to one another to be installed in the inner cavity and detachably connected with the first box body. The plurality of mounting frames are arranged on the plurality of second box bodies in a one-to-one correspondence manner, each mounting frame comprises an opening part and a plurality of mounting parts, the opening parts are used for exposing the second box bodies, and the plurality of mounting parts are arranged around the opening parts at intervals and are used for mounting the filter screens so as to filter lubricating oil containing metal filings. The scrap collecting box solves the technical problems of mixed pollution and inconvenience in operation of a traditional scrap collecting box.

The invention relates to the technical field of sharpening machines, in particular to a broach sharpening machine which comprises a sharpening tool system and a broach movement system, the sharpening tool system is installed on the side edge of the broach movement system, and the broach movement system comprises a broach transverse moving device. The broach turning device, the two broach turning and aligning devices and the two vibration alarm devices are respectively mounted on the broach transverse moving device, each broach turning and aligning device comprises a broach turning frame, a broach turning bearing and a plurality of aligning clamping jaw screw sleeves, and each aligning clamping jaw screw sleeve is mounted on an inner ring of the corresponding broach turning bearing. A clamping jaw rod is installed at the output end of each aligning clamping jaw threaded sleeve, each clamping jaw rod is connected with a broach workpiece in a clamped mode, each vibration alarm device comprises a plurality of sensing pieces, and the sensing pieces are installed on a broach transverse moving device and located on the two sides and the bottom of the broach workpiece respectively. And each sensing piece is externally connected with an alarm, so that the machining precision is high.

An automated grooving device for a tool pliers includes linearly fixedly arranged grooving dies. The grooving dies include a fixed-tooth die, a single-variable die, and a double-variable die. The single-variable die is located below the fixed-tooth die, and the double-variable die is located below the single-variable die. The cross-sectional shape of the fixed-tooth die remains constant. The cross-sectional height of the single-variable die is constant, but its cross-sectional width gradually narrows along its length. Both the height and width of the double-variable die gradually narrow along its length. Oil nozzles are spaced apart in the middle of the grooving dies. In this invention, the cross-section of the grooving dies is designed with a gradual change. By gradually increasing the feed rate during grooving and cutting the jaws, cutting resistance and cutting chips are reduced. The oil nozzles apply lubricating oil to the jaw teeth during the grooving process, improving the smoothness of grooving and reducing problems such as tooth surface roughness and dulling.

A broach or broach segment has a spine. A longitudinal array of teeth protrude from the spine, each tooth having: a first face and an opposite second face; and a distal surface joining the first face and second face; and at least some of the teeth being firtree teeth and have a peripheral trench adjacent the cutting edge of the at least one tooth.