Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23F—MAKING GEARS OR TOOTHED RACKS
  • B23F21/00—Tools specially adapted for use in machines for manufacturing gear teeth
  • B23F21/12—Milling tools
  • B23F21/22—Face-mills for longitudinally-curved gear teeth
  • B23F21/223—Face-mills for longitudinally-curved gear teeth with inserted cutting elements
  • B23F21/226—Face-mills for longitudinally-curved gear teeth with inserted cutting elements in exchangeable arrangement
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T407/00—Cutters, for shaping
  • Y10T407/17—Gear cutting tool
  • Y10T407/1735—Rotary, gear shaving cutting tool

Definitions

• the invention relates to a knife head with a disc-shaped knife carrier comprising a plurality of knife receptacles, and with a plurality of a knife shaft having bar knives, which are inserted with their knife shank in the knife receptacles and their knife shafts seen in cross section have a circular segment-shaped surface.
• a cutter head of this type which is designed to interlock spiral bevel gears, can be taken from DE 101 12 165 B4.
• the blade carrier described herein has blade receptacles whose cross-sectional geometry is composed of a semicircle and a prism.
• the semicircular cross-sectional geometry serves to accommodate a bar knife.
• a clamping wedge is inserted, with the help of the bar knife is attached. For fastening the clamping wedge clamping screws are still provided.
• EP 0 813 927 A2 discloses a knife head which is provided with cylindrical knife receivers which serve to receive substantially round knife shanks. To fasten these round blade shafts holes are provided approximately in the radial direction in the cutter head, which intersect the blade holders approximately in the region of their tangent. In these holes, pulling or pushing wedges are introduced.
• the present invention is therefore based on the object to provide a cutter head of the type mentioned above, which has a particularly simple construction and also ensures a secure fit of the bar blade in the knife holders.
• the object is achieved by a cutter head with the features of claim 1. Thereafter, the blade receptacles form complementary to the blade shafts in cross-section a circular segment-shaped surface, so that the bar knife eino with their knife shafts each accurately fit in the blade holders.
• This embodiment makes it possible to carry out the production of the bar blades or their attachment in the knife holders in a particularly simple and efficient manner.
• a hard metal round bar is necessary whose circular cross-sectional area is flattened by a simple machining operation, such as grinding, so that the blade shank of the bar blade has a flat outer side.
• the complementary design of the recordings manufacturing technology is very easy to implement. Due to the precisely fitting, positive fit of the bar knives in the receptacles, a torsion-proof fit of the bar knives in a defined and exact position is achieved.
• a particular advantage of the embodiment is to be seen in the fact that are not required and not provided for further adjustment elements, such as wedges or the like, for alignment in a defined angular position of the bar.
• the precise alignment in the defined angular position required for high-precision workpiece machining is achieved exclusively by the high-precision design and alignment of the respective blade holder.
• the bar knives only need to be inserted into the knife receptacles without the need for further setting operations. Only the axial position of the bar knives must be adjusted.
• the circular segment-like cross-sectional area of the knife holders also permits a favorable design of webs or material bridges of the knife carrier, which are arranged between two adjacent knife holders, especially in the case of a large number of bar meters.
• the circular segment of the knife cross section covers an angular range with a center angle which is> 180 °.
• the center angle is the angle at the center of a circle over which the arc of the circle segment is defined.
• a larger center angle results in a longer circular arc or a larger cross-sectional area in the measuring shaft and is therefore preferred for reasons of stability. This means that the stability of the bar knife remains relatively high.
• an angular range with a large center angle on a long peripheral side which provides a good fit in the blade holder and offers a large contact surface.
• the center angle is preferably in the range between 220 ° and 270 °. Investigations have shown that such bar knives are characterized by a particularly high stability coupled with high resistance to twisting.
• the blade receptacles are formed by an erosion process.
• EDM processes offer very high accuracy in shaping due to material removal by means of a sequence of electrical charges.
• the desired cut shape is stored and the machine then independently cuts the given shape.
• at least one clamping screw is provided for fastening a respective bar knife, which is screwed substantially radially to the disc rotation axis in the knife carrier.
• the measuring shaft is clamped by means of the clamping screw and secured against axial slipping.
• the respective bar knife is fastened non-positively in the blade receptacle exclusively via the clamping screw.
• the clamping screw presses directly against the measuring shaft and it is applied to any adjusting elements, such as. Clamping wedges, omitted between the clamping screw and the measuring shaft.
• an indirect power transmission is provided by means of a clamping or clamping element with or without damping properties, which is formed between the clamping screw and the measuring shaft and transmits the force formed by the clamping screw to the measuring shaft in a deflection-free manner.
• the bar knife on a clamping side acts on the clamping screw.
• the clamping side is flattened, so that the effect of the clamping screw is not point-like, but flat.
• the clamping side also extends over the length of the blade shaft, so that with different settings of the vertical position of the bar blade in the blade receiving the surface contact with the clamping screw is still guaranteed.
• the clamping side is inclined relative to the longitudinal axis of the bar blade and includes with it an angle which is ⁇ 5 °, in particular about 1 °.
• a wedge effect is achieved.
• the high axial load of the bar blade in use there is a risk that it slips deeper into the blade holder.
• the cross section of the knife bar increases towards its tip.
• the bar blade is secured in its axial position in the blade holder in addition to the non-positive fixation with the clamping screw.
• the blade holder on its circular-segment-shaped surface on an arc portion whose radius is slightly smaller than the radius of the remaining circular-segment-shaped surface.
• the arc section forms, in addition to the flattened side of the blade receptacle, a second defined contact surface for the measuring shaft. This ensures an exact radial positioning or adjustment of the bar knife in the knife carrier.
• the arc portion exceeds an angle between 45 ° and 90 ° and in particular an angle in the range of about 60 °.
• the arcuate portion is further preferably arranged such that it does not directly adjoin the flattened side of the blade receptacle, but that between the arcuate portion and the flattened side, another arc portion is arranged, which has the larger radius.
• This further arc section expediently exceeds an angle of about 5 ° to 30 °, in particular of about 15 °.
• Fig. 1 is a perspective view of a cutter head, consisting of a
• FIG. 2 is a plan view of the knife carrier of FIG. 1,
• Fig. 4 is a plan view of a circular segment-shaped blade holder
• Fig. 5 shows a cross section through a bar knife, trapped in a knife holder.
• like-acting parts are provided with the same reference numerals.
• a cutter head 2 which consists of a disc-shaped and one-piece blade carrier 4 and a plurality of bar knives 6.
• the knife carrier 4 is rotatable about a disc rotation axis A. It has a processing side 8 with a plurality of blade receptacles 10, are received in the bar blade 6.
• the disk rotation axis A passes through the center M of the knife carrier 4.
• the knife holders 10 are arranged in pairs around the center M of the disk-shaped knife carrier 4.
• the knife holders 10 are formed by means of an erosion method and have a circular segment-shaped cross section.
• the knife carrier 4 also has a peripheral side 12 on which mounting holes 14 are mounted in two rows, which extend approximately radially to the disk axis of rotation A. The lower row is arranged directly under the upper and thus columns 16 are formed from two mounting holes 14.
• the number of columns 16 corresponds to the number of blade receptacles 10 or bar knives 6.
• the two mounting holes 14 of each column 16 extend in the same direction.
• the bar knives 6 are inserted into the blade holders 10. Only the wedge-shaped blade tips 18 protrude above the plane of the machining side 8.
• the blade shank 20 of the respective bar blade 6 (see FIG. 3) is formed in the manner of a circle segment when viewed in cross-section.
• the size and shape of the blade rod 20 and the blade receptacles 10 are adapted to each other so that the blade rod 20 is accurately inserted into the blade holder 10 and rests against the walls of the blade holder 10.
• the individual bar blades 6 are in this case formed identical to each other.
• FIG. 2 shows a plan view of the machining side 8 of the disc-shaped blade carrier 4 according to FIG. 1, in which the projections of the fastening bores 14 are shown.
• Circular around the center M of the knife carrier a plurality of knife holders 10 is arranged, each with a circular segment-shaped cross-section. All knife receptacles 10 have the same size and shape, but are mutually offset and twisted in pairs, ie they are at different distances to the center M and close with the radial direction of the disc-shaped blade carrier 4 different angle.
• two mounting holes 14 extend substantially radially, which are formed in the form of a channel.
• Each of the fastening bores 14 serves to receive a clamping screw 22 (according to FIG. 3) which is provided for fastening the bar blade 6 introduced into the blade holder 10.
• FIG. 3 two pairs of clamping screws 22 are shown, which are pressed against the blade shaft 20 by a respective bar blade 6.
• the measuring shaft 20 of each of the bar blades 6 has a circular segment-shaped cross section with a center angle of about 255 °.
• the measuring shaft 20 thus has a rounded side 24 and a flattened side 26.
• the knife tip 18 has the shape of a wedge.
• the rounded side 24 has a tension side 28 that is flat and extends the length of the blade shaft 20.
• the clamping side 28 tapers in the direction of the blade tip 18, so that it is formed in the manner of a triangle.
• Each clamping screw 22 is formed in two parts and usually has a threaded portion 30 and a bolt portion 32. With the help of the threaded part 30, the clamping screw 22 is screwed into the mounting hole 14. The clamping screw 22 is then tightened in the mounting hole 14 until the bolt member 32 is pressed against the clamping side 28 and thus the clamping screw 22 is clamped against the wall of the blade holder 10. In this case, no fasteners in the form of clamping blocks or clamping wedges are necessary to transmit the force of the clamping screws 22, but there is a direct frictional connection between the clamping screw 22 and the bar blade.
• the two threaded parts 30 with a common clamping block 34, the clamping side 28 press.
• the force of the clamping screws 22 is transmitted via the common clamping block 34 on the tension side 28 without deflection in this case.
• FIG. 10 A circular segment-shaped blade receptacle 10 with a rounded side 24a and a flattened side 26a is shown in FIG.
• the rounded side 24a passes over an angular range whose center angle ⁇ is about 255 °.
• the knife holder 10 represents a recess in the disk-shaped knife carrier 4, which is formed by means of a wire EDM process. With the help of wire erosion, all electrically conductive materials can be processed and it avoids the difficulties encountered in machining production in the machining of workpieces with high strength.
• two bores 36 are first introduced into the disc-shaped blade carrier 4, so that the wire can be passed through the disc-shaped blade carrier 4. From the holes 36, a machine accurately cuts the desired shape by guiding the wire along a predetermined distance.
• the measuring shaft 20 is inserted into the blade holder 10 and secured by means of the clamping screw 22.
• the radius R of the rounded side 24 of the blade shank 20 is 8mm in this embodiment.
• the rounded side 24a of the blade holder 10 in contrast, has a larger radius Ri of, for example, 8.1 mm.
• a radius R of 2 is provided, which corresponds to the radius R and in the exemplary embodiment, therefore, 8mm.
• the arc section 38 in the exemplary embodiment at an angle ß of about 60 °.
• the arcuate portion 38 is positioned to laterally join another arcuate portion 40 adjacent to the flattened side 26a.
• the further arc section 38 sweeps - viewed from the center point N - an angle ⁇ of about 15.
• the clamping screw 22 exerts a force against the clamping side 28 of the blade shank 20.
• the knife shaft 20 is pressed in the direction of this force until it rests firmly with its flattened side 26 on the corresponding flattened side 26 a of the blade holder 10 and with a part of its rounded side 24 on the arc portion 38.
• the flattened side 26a of the blade holder 10 and the arc portion 38 are two base surfaces on which the vectorially decomposed force of the clamping screw 22 acts, so that the bar blade 6 immovably and securely clamped in the blade holder 10 at a defined position.
• a defined contact surface for the measuring shaft 20 is predetermined by the arc section 38, which defines the radial position of the respective measuring shaft 20 in the knife carrier 4. Due to the exact design of the arc section 38 when inserting the blade holder 10 into the blade carrier 4, therefore, the respective bar blade 6 is adjusted to a predetermined cutting circle, which is defined by the individual bar blades 6.
• the individual cutting corners of the bar knives 6 must namely lie exactly on a common cutting circle, or in the application of the Vernierens of spiral bevel gears, the cutting corners must be alternately on an inner circle and on an outer circle.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Gear Processing (AREA)
• Shearing Machines (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36809065

Family Applications (1)

Country Status (5)

Families Citing this family (6)

Citations (1)

Family Cites Families (8)

• 2005
  • 2005-07-14 DE DE102005032761A patent/DE102005032761A1/de not_active Ceased
• 2006
  • 2006-05-17 WO PCT/EP2006/004646 patent/WO2007006361A1/de not_active Application Discontinuation
  • 2006-05-17 EP EP06753670A patent/EP1910004A1/de not_active Withdrawn
  • 2006-05-17 CN CNA2006800251037A patent/CN101218059A/zh active Pending
• 2008
  • 2008-01-11 US US12/013,097 patent/US20080170915A1/en not_active Abandoned

Patent Citations (1)

Non-Patent Citations (1)

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