MXPA01000065A - Method for grinding at least one surface on a cutting knife used in machining, use of said method and grinding wheel used to carry out said method - Google Patents

Abstract

A grinding wheel (28) that rotates around an axis and that has a working area consisting of a ring area with a circular arc profile is used to create a surface by initial grinding with the ring surface oriented at a first point in space between the grinding wheel (28) and the cutting knife (22) by means of at least one first translational relative movement between the same, and subsequently by grinding at least one part of the surface produced with the ring surface oriented at a second point in space between the grinding wheel (28) and the cutting knife (22) by means of at least one second translational relative movement between the same. The grinding wheel (28) is a diamond cupped grinding wheel. One part (34') of the working area (34) is located in a face area and another part (34") is located in a cylinder area of the grinding wheel (28). One part (34') is used for roughing down and the other is used to smooth-polish the surface that is to be created on the cutting knife (22). The grinding wheel (28) has the same abrasive covering for the entire working area (34). Roughing down and smooth-polishing occur using areas of the grinding wheel (28) that have the same specifications but different grinding parameters. Preferably, spatial orientation between the grinding wheel (28) and the cutting knife (22) is selected by adjusting the cutting knife (22) in relation to the grinding wheel (28). The inventive method enables planar and/or convex and concave surfaces to be created on a cutting knife.

Description

METHOD TO MILL AT LEAST ONE SURFACE ON ONE CUTTING KNIFE USED IN MACHINING. USE OF THE METHOD AND ESMERIL WHEEL USED TO CARRY OUT THE METHOD DESCRIPTIVE MEMORY The invention relates to a method for grinding at least one surface on a cutting blade used in machining, with an emery wheel rotating about an axis and having a working area consisting of an annular surface; to an advantageous use of the method; and an emery wheel used to carry out the method. Currently, there are two techniques for grinding cutting blades used in machining, namely, shape grinding and generator grinding. The main difference between these two grinding techniques is that in the grinding of form, the generatrix is produced in the tool in operation (revival). In this way, a simple procedure is created in which the emery tool carries the profile. Only a feed movement is then required to form a surface. Contrary to this, in the grinding generator, the generator is produced by at least two machine movements, which complicates the procedure. However, the grinding generator is more flexible than the shape grinding, since a variety of profiles can be produced by any combination of movement. Increased flexibility is highly desirable if lots of special small or medium size profiles have to be produced. In this case, it is not necessary to rekindle the generator profile on the grinding wheel. However, the grinding of the generator requires a more elaborate control than the shape grinding. From the patent of E.U.A. 5,168,661 a method of the type given above is known. In this known method, a special emery wheel configuration and a particular sequence of movements are used when moving the cutting blade relative to the grinding wheel, to allow the formation of a plurality of desired surfaces on a cutting blade. In addition, spiral grooves produced on the surface of the piece by the grain that stands out from the grinding wheel will be avoided. For this purpose, the known method uses a profile grinding wheel which is described and illustrated in US 5 168 661 A mentioned above, but which is claimed in US 5 241 794. This profile grinding wheel has a profile of Emery, which for finishing grinding has a substantially flat narrow surface on the outer portion of the grinding wheel. This flat surface is maintained substantially tangent to a workpiece surface during finishing grinding. This profile grinding wheel consists of an expensive, highly durable abrasive material such as CBN crystals. However, other materials such as aluminum oxide can also be used, since the profile grinding wheel does not need to be re-revived. In addition to the narrow, flat surface used for finishing grinding, the working area of the known profile emery wheel has an internal conical surface, an internal arcuate surface and an external arcuate surface. The internal conical surface, the internal arcuate surface and / or the external arcuate surface is used for rough grinding. The rough blade surface is subsequently finished with the narrow flat surface. This known method requires a complex sequence of movements, because each surface to be ground on the cutting blade is first roughly trimmed at least with the inner conical surface and then finished with the narrow flat surface. The profile grinding wheel used in the known method comprises materials with different grain sizes in their rough grinding and finishing grinding areas. The work of roughing and finishing that will realize the known wheel of emery is in this way distributed on the two different areas of emery wheel, of which the first area is used only for rough grinding and the other only for finishing grinding. Cutting blades ground with the known method are common blades of high speed steel. A further disadvantage of the known method is that it is not possible to grind concave surfaces, since the finishing grinding always takes place with the narrow flat surface. Another disadvantage of the known method of grinding generator is that due to the CBN wheels used in this method, cemented carbide blades can not be grinded. A CBN wheel would not be properly stable to machine cemented carbide blades. However, the cemented carbide blades could not be frosted. A large diamond wheel would be necessary to grind cemented carbide blades. However, such diamond wheels are very difficult to condition. For example, to produce the teeth of a gear it may be necessary to use six different types of blades in order to produce six different profiles. These six profiles can be produced by reprofiling on a shaker wheel. This would not be economical on a diamond grinding wheel. Instead, they would have to provide different diamond wheels for shape grinding. The object of the invention is to provide a method of the type given above, having a simpler machining cycle and allowing the use of a grinding wheel of simpler configuration, and particularly allowing the grinding to also take place on curved surfaces. In addition, an advantageous use of the method and an emery wheel will be provided to perform the method. The object is made according to the invention by the method given in claim 1, by the use defined in claim 15 and / or by the grinding wheel according to claim 16. In contrast to the known method that uses a wheel of emery with a complex configuration, in the method according to the invention can be used a universal grinding wheel which has a working area consisting of an annular surface, whose axial cross section has an arched profile. With the method according to the invention, a surface is first generated on the cutting blade when grinding with the annular surface during a first orientation in space between the grinding wheel and the cutting blade by means of at least a first relative movement of translation between the grinding wheel and the cutting blade, and then at least a part of the generated surface is re-ground with the annular surface during a second orientation in space between the grinding wheel and the cutting blade by means of at least a second relative movement of translation between the grinding wheel and the cutting blade. According to the invention, a surface can be ground with an area of the annular surface, and this can be re-merged with another area of the annular surface. The grinding wheel used in the method of the invention does not need to have different specifications for this in these two areas. That is, because the same surface of the cutting blade can be ground and subsequently re-wetted, that is roughing and finishing, for example, only through the selection of suitable parameters together with the two different spatial orientations. This is true, regardless of whether the finished surface is flat, convex or concave. The grinding wheel used in the method of the invention only needs a radius in its work area, and therefore, has a substantially simpler configuration than the grinding wheel used in the known method. The method in the method according to the invention is also simpler than in the known method, because only two different spatial orientations can be selected, for example by selecting a different angle for the cutting blade relative to the wheel of emery In this way, the method according to the invention is by far more flexible in use than the known method. Spiral-shaped grooves, which are avoided in the known method by complicated means, are also avoided by the method according to the invention, without the need to use an emery wheel with a narrow flat surface for finishing grinding. . It is possible to generate cemented carbide blades using the method according to claim 15. This is a very important application of the method according to the invention, since dry milling, in which carbide cutting blades have to be used Cemented, it is becoming more common in gear production. Cemented carbide can only be machined with diamond, but diamond profile grinding wheels can hardly be profiled by revival. Therefore, the profile grinding of cemented carbide blades is virtually ruled out. In this way, simply by the use of a diamond grinding wheel, the method according to the invention can be implemented not only for the grinding generator of cutting blades of high speed steel, but also for the cutting blades of Cemented carbide. To carry out the method according to the invention, an emery wheel is used according to the preamble of claim 16, which has a work area similar to that provided in an emery wheel of US 5 259 148 A , but which is provided for the grinding glass lens generator. The use of such a diamond cup type grinding wheel with a work area located partially in a leading area and partly in a cylindrical area of the cup type grinding wheel, offers the advantage that grinding flat or curved surfaces (with the front area) or alternatively, concave surfaces (with the cylindrical area or the front area) can be grinded in a cutting blade used in machining, depending on the spatial orientation between the grinding wheel and the cutting blade. The performance with respect to wear improves with a diamond grinding wheel and the geometry of the wheel becomes more stable than in the known CBN profile grinding wheel. The diameter of the so-called profiling point, which can be determined precisely, no longer changes during a technological phase compared to a CBN grinding wheel. Therefore, it is not necessary to compensate the position of the diamond grinding wheel. In addition, in a separate technological step, a blade gap with a larger oversize can be produced, thus contributing to the increased economic feasibility of the process. Because in the emery wheel according to the invention, the working area consists of an annular surface having an arched profile in an axial cross section extending through a total contact angle, the working areas of roughing and finishing of the grinding wheel can be moved relative to each other or even be separated within this work area by selecting different profile inclination angles. Because the total contact angle is approximately 145 °, the part of the work area used can be selected in the front area and / or the cylindrical area of the grinding wheel. Due to the circular arc profile provided in the grinding wheel according to the invention, with a radius of curvature that is within a scale of 0.5 to 5 mm and preferably 0.5 to 1 mm, and preferably 0.5 mm or less, possibilities of flexibility in the machining of the cutting blade are offered. The cutting blades that will be ground using the method according to the invention, can comprise different types of cemented carbide. A side of a blade generated with the grinding wheel according to the invention may comprise one or more geometric surfaces. The surface and side shape is produced by the relative positioning of the grinding wheel and the cutting blade. In this sense, the cylindrical area of the grinding wheel generates a concave surface, while the front area can generate a curved or flat surface. Therefore, the blade side may comprise two or more than two different surfaces (e.g., a concave surface with a greater relief angle, and a flat facet with a minor relief angle). Advantageous embodiments of the invention form the subject matter of the subclaims. In an advantageous embodiment of the method according to the invention, the first space orientation between the grinding wheel and the cutting blade is obtained by fixing a first position of the cutting blade in relation to the grinding wheel, and the second Orientation in space between the grinding wheel and the cutting blade is obtained by fixing a second position of the cutting blade relative to the grinding wheel. In this case, a conventional grinding machine can be used, in which the grinding wheel rotates around its own axis and moves on the Y axis. In another advantageous embodiment of the method according to the invention, the first position of the The cutting blade is selected in such a way that the grinding wheel generates the surface on the cutting blade with a first surface element of the annular surface located in a cylindrical area of the grinding wheel, and the second position of the grinding blade. The cut is selected in such a way that the grinding wheel grinds at least the part of the surface generated in the cutting blade with a second surface element of the annular surface located in the front area of the grinding surface. In this case, the concave surface generated with the cylindrical area may alternatively be re-merged with the front area, such that the generated surface remains concave or becomes flat or at least partially flat. In a further advantageous embodiment of the invention, the second position of the cutting blade is selected in such a way that the grinding wheel generates at least the part of the surface generated in the cutting blade as a concave or flat facet. In this case, only the spatial orientation between the grinding wheel and the cutting blade needs to be selected in accordance. In a further advantageous embodiment of the method according to the invention, the removal of material during generation of a surface on the cutting blade occurs only through feeding on a Y axis of the machine. In this case, the generator grinding process can be easily controlled. In another advantageous embodiment of the method according to the invention, the surface on the cutting blade is generated only with three mutually orthogonal linear axes, and other axes are simply used as adjustment axes and placed before the actual surface generating grinder. on the cutting blade. In this case, each desired surface can be generated in the cutting blade with three controlled linear movements in a conventional grinding machine such as the B22 type of the applicant (compare with the company brochure "CNC-Werkzeugschleifzelle Oerlikon B22" OGT -B22 / D / hJ or type B5 of the applicant (compare the two company brochures both titled "profil B 5", sections 1.11-d / e-cH and OGT-profil B5 / E / dH, respectively). A further advantageous embodiment of the method according to the invention, the surface in the cutting blade is generated in one and / or the other step in two operations by means of two first movements and two second relative movements of translation between the grinding wheel and the cutting blade, respectively, In this case, the surface can be trimmed and finished in two steps each In a further advantageous embodiment of the method according to the invention, the method is carried out in a machine. In this case, the grinding process can be controlled in a conventional manner with respect to geometry and technology. In another advantageous embodiment of the method according to the invention, a CDS computation system is used (CDS is the abbreviation of Controlled Disk System) to determine the interrelations between geometrical and technological parameters for the generator grinding. In this case, all that is required is a special software package to convert a conventional grinding machine such as the aforementioned B22 type, into a grinding generator according to the invention. In another advantageous embodiment of the method according to the invention, the surface in the cutting blade is generated in at least one step with at least one roughing cut, and at least part of the generated surface is re-ground with a finishing cut. in another step. In this case, each surface can be generated separately and the geometries of the macro and micro surfaces can be influenced separately. In another advantageous embodiment of the method according to the invention, the relative movement of translation between the grinding wheel and the cutting blade takes place by imparting a driving or pushing movement to the cutting blade relative to the grinding wheel. In this case, the desired simple machining cycle can be achieved through the corresponding selection of this movement. In another advantageous embodiment according to the invention, a thrust movement relative to the grinding wheel is imparted to the cutting blade during re-milling with a finishing cut. Although this is the preferred method, an impulse movement for the finishing cut can be arranged in place of the pushing movement, depending on the surface to be ground. Each technological step (roughing or finishing) can be defined geometrically and technologically separately in the convenient modalities of the method according to the invention. In another advantageous embodiment of the method according to the invention, an emery wheel is used which has the same specifications over its entire annular surface used for grinding. In this case, it is convenient to select the roughing cut and finishing cut only through the selection of power parameters, such as direction and feed speed. In another advantageous embodiment of the method according to the invention, the roughing and finishing are interchangeable in the two steps of the method according to the invention and therefore, are the surface elements of the annular surface used for grinding. To be sure, two technological phases, roughing and finishing, may be required. However, the technological process can include a plurality of roughing cuts and a finishing cut and vice versa. In another advantageous embodiment of the grinding wheel according to the invention, the grinding wheel has a fixed geometry and can not be revived. This makes its production especially simple. It is much easier to perform the grinding only with a specific radius if the radius remains constant. This is the case with diamond grinding wheels, which have a long lifespan. It can be assumed that the method is carried out with a constant radius, which simplifies and facilitates the control of the procedure. The question of whether an emery wheel that can be revived or that can not be revived is used depends on the grinding capacity of the grinding wheel. Preferably, a non-revolving emery wheel comprises a metal vehicle body on which an abrasive coating of diamond grain and a galvanic bond from which the diamond grain protrudes is applied, with the galvanic connection preferably consisting of nickel. You can use an emery wheel that can be revived instead of an emery wheel that can not be revived. This is possible due to the design of the type B22 machine, since it has an adequate revival medium and adequate revival software is provided to allow occasional revival of the grinding wheel in order to re-profile its radius.

The embodiments of the invention are described in more detail below with reference to the drawings, in which Figure 1 shows a conventional grinding machine type B22 of the applicant, which has been equipped by the further development of its software to perform the method according to the invention; Figure 2 shows a schematic drawing of a cup-type grinding wheel for the method according to the invention; Figure 3 shows an explanatory drawing of the grinding wheel according to the invention; Figure 4 shows an enlarged detail drawing of the working area of the grinding wheel according to the invention; figures 5a-5c show three different types of cutting blade which can be ground using the method according to the invention in a machine according to figure 1, with the left side of each figure showing the arrangement of the blade cutting on a cutter head and the right side showing the arrangement of the cutting blade in the grinding machine attachment; Figure 6a shows the distribution of cut on a cutting blade with different material removal in the blade shoulder and the tip of the blade; Figure 6b shows the cut pattern on a cutting blade with approximately constant material removal at the blade shoulder and at the tip of the blade; Figure 7 shows the use of the method according to the invention for grinding by roughing the surface of a cutting blade in two operations; figure 8 shows the use of the method according to the invention for finishing grinding the same surface as in figure 7, figure 9 shows the grinding of a shoulder on a cutting blade by means of the emery wheel according to the invention, in the type B22 grinding machine with software developed subsequently, figure 10 shows the different grinding positions possible for different process steps for grinding a cutting blade by means of the grinding wheel according to the invention, the figure 11 shows the grinding by roughing of a relief side in a cutting blade by means of the emery wheel according to the invention; Figure 12 shows the finishing grinding of the same relief side as in Figure 11 by means of the grinding wheel according to the invention; Figure 13 shows the determination of the work area of the grinding wheel during roughing; Figure 14 shows an explanatory drawing of how a total contact angle GKW is shifted by changing a profile inclination angle PKW; Figure 15 shows the determination of the working area of the grinding wheel according to the invention during finishing; Figure 16a shows the conditioning of an emery wheel that can be revived by means of a contour roller when applied to the contour of the grinding wheel, and Figure 16b shows the conditioning of an emery wheel according to the invention by means of a revival roller by interpolation around the contour of the grinding wheel. Figure 1 shows a blade grinding machine type B20 of the Applicant, referred to in its entirety as B22. Normally, this machine is provided for grinding bar knives by means of profiled wheels in a shape grinding process. Here, however, it has been extended to grind cutting blades, particularly cemented carbide blades, in a generator grinding process. Mainly, the expansion comprises the expansion of the software to control the blade grinding machine 20, especially in the area of adaptation control (PMC), machining cycles and CNC macros, the user interface and data management with an integrated PC. He CNC works like the "master" and serves for axes control, execution of part programs (procedure sequence control), parts program management, and for screen displays.

CNC The adaptation control, also referred to as a programmable control, is responsible for the interface function between the CNC and the blade grinding machine, the control of the sequences of machine operation, monitoring functions, operator panels of the machine , digital input / output and interface to the robot / feeder tank. Due to the available resources (RAM in the PC) a program is established for the user interface for each of the two grinding procedures (shape grinding and grinding generator). The change between the user interface for the shape grinding or the grinding generator can be done during the start phase of the PC software. The blade form is generated only with the linear axes X, Y, Z. An axis A and a C axis only serve as adjustment axes and are placed before the actual generator grinding of the knife surfaces. The calculation of cutting trajectory and distribution is made in the PC, so that only macros and cycles have to be provided for part exchange and conditioning of the grinding wheel at the CNC level. The main interpolation plane for grinding cutting blades is formed by the Y and Z axes. The part spectrum comprises cutting blades 22, of which three different types are described in Figures 5a-5c. The structural geometry and the arrangement in one head of the cutter 24 are different in the three types of blade. Accordingly, the three types of blades are ground in three different clamping fixtures 26. The left part of figure 5a shows an angle of relief of 8 ° and a blade inclination angle of 20 ° in the head of the cutter. Accordingly, the cutting blade 22 to the right of FIG. 5a must have an inclination angle of 28 ° in the clamping fixture 26 so that the head of the blade is arranged to grind without relief angle. This is analogous to Figures 5b and 5c. The angles shown at the left end and at the upper left end in Figures 5a and 5c are not of interest for the present description and therefore, do not require further explanation. In the generation of the surface in the cutting blade 22, the removal of material is done only by feeding on the Y axis of the machine, as suggested in figures 1 and 5a. The properties of the axis A of the knife grinding machine 20 shown in FIG. 1 are an important prerequisite for the method described herein, which has been specially developed for grinding cemented carbide. In the conventional method of shape grinding, the axis A serves only to place the apparatus and then it is fixed. The head radius is produced by at least two translation movements (Y, Z). These translation movements are described in more detail below with reference to FIGS. 7-15. The generator grinding method described herein is performed with an emery wheel 28, which is preferably an emery wheel type cup. Diamond. In Figure 2, an axial cross section of the grinding wheel 28 is schematically represented and an extended portion thereof is shown in its working position in Figure 3. In the embodiment shown in Figure 3 and described herein , the grinding wheel 28 comprises a steel vehicle body 30 on which an abrasive coating 32 comprising grain and a galvanic connection is applied. The galvanic connection consists of nickel that has been deposited electrolytically in the steel vehicle body 30 in galvanic baths. The diamond grains (not shown individually) stand out from the union that exists at the end of the galvanic treatment. An emery wheel that can be revived can be joined with synthetic resin. In addition, reference is made to Figure 4, which shows an even larger enlargement of a work area 34. The grinding wheel 28 has a grinding radius or radius of curvature R. A portion 34 'of the work area 34 is located in a front area and a portion 34"of the work area 34 is located in a cylindrical area of the grinding wheel 28. The grinding wheel 28 has a fixed geometry and can not be re-lit. If the useful life has been finished, the working area 34, that is to say the active surface of the grinding wheel, can be coated. According to the drawing in figure 3, the grinding wheel 28 has a radius of grinding or radius of curvature R at the grinding edge.; an SR wheel radius to a tangent to the grinding edge; a wheel height SH from a spindle contact surface 36 to a tangent to the grinding edge; an internal angle IW of an inner surface (cone) 40 to the axis 38 of the grinding wheel 28; and an external angle AW of an external surface (cone) 42 to the shaft 38. The working area 34 of the grinding wheel 28 comprises an annular surface extending as shown in Figure 4 from a point 44 in the front area to a point 46 in the cylindrical area of the grinding wheel 28, and having an arcuate profile in its axial cross section shown in Figure 4, extending over a total contact angle GKW, which is shown in the figures 13 to 15 and which will be described in more detail with reference to these figures. The total contact angle GKM is approximately 145 °. The arched profile is in the form of a circular arc, and the radius of curvature is within a scale of 0.5 to 5 mm, preferably 0.5 to 1 mm. The grinding wheel has one and the same abrasive coating throughout the work area 34. That is, the different parts of the work area do not have to be provided with different coatings for roughing or finishing. The respective coating limits of the work area 34 are referred to as 48 and 50 in Figure 4. The excess length by which the coating boundary extends beyond the actual work area is designated 52 and 54, respectively. The angle within which the grinding wheel 28 may be in contact with the head of the cutting blade 22 during grinding is referred to as the head contact angle KKW. The contact angle of the head for use of the grinding wheel 28 in roughing corresponds to the part 34"of the work area, and the finishing corresponds to the part 34 'of the work area, as indicated in figure 4 The use of these different parts of the work area for roughing and / or finishing is described in more detail below: A cutting blade in which the grinding is performed has three active surfaces, namely two relief sides 56 (of which only one is visible in Figure 5a) and a slope side 58. These three surfaces can be defined separately in the knife grinding machine 20 and subsequently separately grinded in. Each relief flange may comprise two different surfaces ( with two different relief angles and with two geometries.) The technological procedure can include a plurality of roughing cuts and a finishing cut.Each procedure phase (roughing or finished) or ignition operations can be defined separately. Figures 13, 14 and 15 schematically represent the roughing and finishing techniques. In the finishing (Figures 13 and 14), the cutting blade 22 is inclined by a profile inclination angle PK, so that the working area 34 is brought into contact with the cylindrical area of the grinding wheel 28. the relief side which is thus generated in the cutting blade, becomes concave in the side and cylindrical in the head of the cutting blade 22. The generator grinding method described herein provides that the "relief side" roughing "is frosted with a relief angle greater than the" finish relief side ". Figures 13 and 14 clearly show that the total contact angle GKM depends on the profile inclination angle PK. The profile contact angle PKW is within a range of alpha to 90 ° -alpha. For different angles of inclination of profile PK, the different parts 34 ', 34"of the working area 34 of the grinding wheel 28 are in contact with the cutting blade 22. In this way, the roughing parts and the parts of The finishing of the working area 34 of the grinding area 28 can be displaced in relation to one another or even separated.The separation limit is at PK = 90 ° -alfa (with different methods of grinding: impulse or thrust). 14 serves to illustrate how the profile inclination angle PK shifts the total contact angle GKM For the finishing grinding phase, described with reference to Figure 15, the blade profile is positioned vertically (PK = alpha). The grinding wheel 28 operates the side of the cutting blade 22, where the generatrix is an arc in a plane. On the side, a flat or cylindrical facet is produced, whose width can be calculated. However, a theoretically exact cylinder is not produced in the head of the cutting blade 22, but a correct cutting edge is given. The "finish relief angle" setting is lower than the setting for roughing. In this way, the two different surfaces are generated. Of course, the value of the "finishing relief angle" must be correct for the machining process. As mentioned above, the different areas 34"and 34 'of the grinding wheel 28 are used by deferring the position of the cutting blade 22 during roughing and finishing, respectively, resulting in an increased service life. profile inclination is less than 90 ° -alpha, there will always be an area of overlap between roughing and finishing Figure 6 shows the distribution of cut for a blade machining, in which the removal of material is done only by In this procedure, the removal of material in the blade shoulder and the tip of the blade is substantially greater than the lateral surfaces, if the grinding technique dictates that the removal of material is approximately constant, an appropriate cutoff distribution must be calculated.The additional intermediate positions must then be converted in due order into a parts program CNC with the correct sequence of grinding operations. Additional grinding operations are marked with shaded lines in Figure 6b. The machining of the blade is described in more detail below with reference to FIGS. 7 and 8, using the example of a surface that was cut in two operations and subsequently finished. For roughing in two operations, the positions set as 0-14 can be reached with the cutting blade, which is clamped in the clamping fixture 26 (compare figure 5a) not shown in figures 7 and 8. The first operation is shown to the left of figure 7 and the second operation to the right. The grinding wheel 28 maintains its respective position, and the positions shown by the cutting blade 22 are reached, although the illustration in FIGS. 7 and 8 is such that the grinding wheel 28 appears to move. However, as shown in Figure 1, this can only be moved on the Y-axis. The attachment 26 in which the cutting blade 22 is secured, carries the movements on the X, Z axes and if necessary , on the Y axis.

In Figure 7, O is the initial position that can be reached without shock from a standard position. This position corresponds to X = 0, Y = 0, Z = 0, with the displacement to zero effective. Short dashed arrows indicate fast-speed movement and long dashed arrows indicate feed speed. 1 designates the approximate polygon point at fast speed. 2-6 are the points in the path of the first operation that are approximate in the feed rate. Points 7 and 8 are approximate intermediate points at fast speed. Points 9-14 are points in the path of the second operation at which the feed rate is reached. The withdrawal from the standard position occurs at fast speed from point 14 forward. 0 in figure 8 again indicates the initial position that can be reached without shock from a standard position. 1 is the first point in the trajectory, which is still approximated at fast speed. 2-6 are points in the path that are approximate to the feed rate. The withdrawal from the standard position occurs at fast speed from point 6 onwards. Figures 9-12 show how the work operations schematically shown in Figures 7 and 8 actually work in the blade emery machine 20. The cutting blade 22 in Figure 9 is adjusted in such a way that the emery wheel 28 grind a surface (A) of the cutting blade 22 using the portion 34"of its work area located in the cylindrical area.

That is, it grinds the surface by grinding, starting from a shoulder 21 to a head 23 of the cutting blade 22. Figure 10 shows the different grinding positions possible for different technological stages for grinding the cutting blade 22 with the grinding wheel. Emery 28. According to the drawing of Figure 11, the other surface (B) of the cutting blade 22 is ground by means of the working area part 34"located in the cylindrical area. According to the drawing of figure 12, the surface previously cut on the cutting blade 22 is then placed in a vertical position in which it is tangential to the front area of the grinding wheel 28. This surface of the blade 22 is finished in this position The adjustment of the blade in relation to the grinding wheel, which is movable on the Y axis, will now be described in detail with reference to figures 13-15. to one of Figures 13-15 only the ground edge of the emery wheel 28 is suggested by a circle shown on the cutting edge in Figure 4. The emery wheel, which is not otherwise shown, has the same orientation as in figure 4, that is, its face extends vertically and the axis of rotation is horizontal. The finishing and roughing techniques are shown schematically in Figures 13-15. In roughing (Figures 13 and 14), the cutting blade 22 is inclined by the profile inclination angle PKW, so that the profile is brought into contact with the cylindrical area of the emery wheel 28. In this way , a relief side is generated which is concave on the side and cylindrical on the head 23 of the cutting blade 22.

Preferably, the grinding on the "rough relief side" is carried out with a relief angle greater than that of the "finishing relief side". Figures 13 and 14 clearly show that the total contact angle GKW depends on the angle of inclination of the profile PKW as already explained above. The profile of the blade is placed vertically (PK = - alpha) for the finishing phase (figure 15). Emery wheel 28 works the side of the cutting blade with its face, where the generatrix is an arc in a plane, as already discussed. As mentioned above, different parts of the working area 34 of the grinding wheel 28 are used as the position of the cutting blade is deferred during roughing and finishing. Of course, the feeding direction (impulse or push) is important in this aspect. The method described above for grinding at least one surface on a cutting blade 22 used in machining, using an emery wheel 28 that rotates about axis 38 and having a work area 34, consists of an annular surface with its cross section axially in the form of an arched profile (compare particularly with figure 4), can be summarized as follows: a) first, a surface is generated in the cutting blade 22 when grinding with the annular surface during a first orientation in space between the emery wheel 28 and cutting blade 22 by means of at least a first relative movement of translation between the grinding wheel and the cutting blade, as shown for a surface in figure 11, for example, and b) subsequently, at least a part of the generated surface is re-merged with the annular surface during a second orientation in space between the grinding wheel 28 and the cutting blade 22 by means of minus a second relative movement of translation between the grinding wheel 28 and the cutting blade 22, as shown in Fig. 12. Preferably, in this regard, the first and second spatial orientations between the grinding wheel 28 and the blade 22 are obtained by fixing a first and a second respective position of the cutting blade 22 relative to the grinding wheel 28. Depending on the inclination of the cutting blade 22 in FIG. 12, at least a portion of the The produced surface is generated in the cutting blade 22 by the grinding wheel 28 as a concave or flat facet. For practical purposes, the removal of material during the generation of the surface on the cutting blade 22, occurs only through feeding on the Y axis of the machine. It is essential for the invention that only relative translation movements be made between the cutting blade 22 and the grinding wheel 28. Neither the grinding wheel 28 nor the cutting blade 22 need to be rotated during work on the blade, except for of course, by the rotation of the grinding wheel 28 on its own axis 38. Here, the surface on the cutting blade 22 can be generated in step a) and / or in step b) in two operations by two first movements and two relative second translation movements between the grinding wheel 28 and the cutting blade 22, respectively. It has already been indicated that the method is preferably carried out on a CNC machine and that a CDS computer system is used to determine the interrelations between geometrical and technological parameters for the generator grinding. Furthermore, based on an example, it has been described above that the surface on the cutting blade 22 is generated in step a) in two operations, that is with two roughing cuts. However, it is clear that at least one roughing cut is sufficient. At least a part of the generated surfaces is then re-ground with a finishing cut in step b). The relative movement of translation between the grinding wheel 28 and the cutting blade 22 is produced by imparting an impulse movement (as shown in Figs. 13 and 14) or a pushing movement (as shown in Fig. 15) to the cutting blade 22 relative to the grinding wheel 28. The special advantage of the grinding wheel 28 used in the method described herein is that the grinding wheel has the same specifications on the entire annular surface used for grinding, that is, for example that the entire work area of the grinding wheel has one and the same abrasive coating, and that the roughing and finishing cuts are selected only through the choice of feeding parameters, such as direction and speed of feeding, cutting speed and excessive measurement. The surface elements of the annular surface that are used in steps a) and b) for roughing and finishing, respectively, are interchangeable. The method described herein is preferably used to grind cemented carbide blades by means of a diamond cup type grinding wheel. Emery wheel 28 can be revived or can not be revived. If an emery wheel is used that can be revived, the revival can be carried out using the following methods: - revive with a contour roller (figure 16a) that has a negative correction. In this case, no additional axial movements are required apart from the approach to the grinding wheel 28, or - reviving with a contour roller 68 having an outline similar to that which is commonly used. In this case, an outline has to be drawn around the profile of the wheel with the contour roller 68. Due to the inclined axis of the revival screw, the commonly existing arrangement of the revival unit can not be used for this. The control must be informed by a new input signal that the revival device (contour roll 66 or 68) has been set for the diamond cup type grinding wheel, so that the scale limit switches can then be activated of software and that additional monitoring and credibility controls can be made regarding the grinding procedure. Figure 16a schematically represents the conditioning by means of the contour roll 66, with linear interpolation in the approach to the contour of the grinding wheel. Figure 16b shows the conditioning with the contour roller 68 by interpolation around the contour of the emery wheel. In both cases, the conditioning process can be carried out at different relative speeds of the contact points of the cup-type wheel to the revival tool, in order to achieve the desired surface quality or removal capacity of the grinding wheel 28 The actual revival procedure will be a cycle that is in file in the CNC and which has access to the data of the tool database. The conditioning procedure according to Figure 16b can be carried out if the condition for the spokes and the slope of the cone has been met. Then, a theoretical point contact occurs between the grinding wheel 28 and the revival roller 68. The revival cycle will be established in such a way that a revival roller with a cylindrical part and with a radius each can be applied to the edge. To be sure, it is stated above that at least two translation movements are necessary, that is, one for the side of the cutting blade 22 and another for the head 23 of the cutting blade 22. However, an third additional translation movement.

The optimization performed in the generator grinding method described here, for example, may consist in that the force on the grinding surface remains constant. To achieve this optimization it is possible, for example, to design the surfaces on the cutting blade 22 so that the cutting exit of the grinding wheel 28 always remains the same. The manufacturer of the grinding wheel generally recommends a certain cutting output, which should be observed. It is then possible for the user to adapt the knife surfaces to be grinded to this. A controlled cutoff distribution such as that described above with reference to FIGS. 6a and 6b, allows for an improved optimization of the grinding process, ie, uniform force output, production of a desired facet width, etc. A further optimization consists in that the final state of the ground surface may be optionally flat or concave and that in turn, each relief side may comprise a combination of two separation areas. For this, it is only necessary to select the orientation in space between the grinding wheel 28 and the cutting blade 22, combined with a driving or pushing movement of the cutting blade 22, as explained above. In this way, the method described herein is extremely flexible.

Industrial application An emery wheel that rotates around an axis and that has a working area consisting of an annular surface with a circular arc profile in axial cross section, is used to first generate a surface on a cutting blade when grinding with the annular surface during a first orientation in space between the grinding wheel and the cutting blade by means of at least a first relative movement of translation between them, and subsequently at least a part of the generated surface is re-ground with the surface annular during a second orientation in space between the grinding wheel and the cutting blade by means of at least a second relative movement of translation between them. The grinding wheel is a grinding wheel type diamond cup. A part of the work area is located in a front area and another part is located in a cylindrical area of the grinding wheel. The first part is used for grinding by roughing and the other part is used to finish grinding the surface that will be generated in the cutting blade. The grinding wheel has the same abrasive coating for the entire work area. In this way, the roughing and finishing are carried out using areas of the wheel of emery that have the same specifications but different parameters of grinding. Preferably, the spatial orientation between the grinding wheel and the cutting blade is selected by adjusting the cutting blade relative to the grinding wheel. The method allows flat and / or concave surfaces to be generated in a cutting blade. It also allows a simpler sequence of operations and allows an emery wheel to be used, which has a simpler configuration than the most novel.

Claims (19)

NOVELTY OF THE INVENTION CLAIMS

1. - A method for grinding at least one surface on a cutting blade (22) used in machining, with an emery wheel (28) rotating around an axis (38) having a working area (34) consisting of an annular surface having a circular arc profile in axial cross section, comprising a) generating a surface on the cutting blade (22) when grinding with the annular surface during a first orientation in space between the grinding wheel (28) and the cutting blade (22) by means of at least a first relative movement of translation between the grinding wheel (28) and the cutting blade (22), and b) re-smearing at least a part of the surface generated with the surface annul during a second orientation in space between the grinding wheel (28) and the cutting blade (22) by means of at least a second relative movement of translation between the grinding wheel (28) and the cutting blade (22) .

2. The method according to claim 1, further characterized in that in step a) the first orientation in space enters the grinding wheel (28) and the cutting blade (22) is obtained by fixing a first position of the cutting blade (22) in relation to the grinding wheel (28), and because in step b) the second orientation in space between the grinding wheel (28) and the cutting blade (22) is obtained by fixing a second position of the cutting blade (22) in relation to the grinding wheel (28).

3. The method according to claim 2, further characterized in that the first position of the cutting blade (22) is selected so that the grinding wheel (28) generates the surface on the cutting blade (22) with a first surface element of the annular surface located in a cylindrical area of the grinding wheel (28), and in that the second position of the cutting blade (22) is selected so that the emery wheel (28) grinds the less a part of the surface generated in the cutting blade (22) with a second surface element of the annular surface located in a front area of the grinding wheel (28).

4. The method according to claim 3, further characterized in that the second position of the cutting blade (22) is selected such that the grinding wheel (28) generates at least a part of the surface generated in the cutting blade (22) as a concave or flat facet.

5. The method according to any of claims 1 to 4, further characterized in that the removal of material during the generation of surface in the cutting blade (22) occurs only through feeding on a Y axis of the machine.

6. The method according to any of claims 1 to 5, further characterized in that the surface on the cutting blade (22) is generated only with three mutually orthogonal linear axes (X, Y, Z), and other axes ( C, A) are used only as adjustment axes and are placed before the actual generator grinding of the surface in the cutting blade (22).

7. The method according to any of claims 1 to 6, further characterized in that the surface in the cutting blade (22) is generated in step a) and / or in step b) in two operations by means of two first movements and two second relative movements of translation between the grinding wheel (28) and the cutting blade (22), respectively.

8. The method according to any of claims 1 to 7, further characterized in that the method is performed in a CNC knife grinding machine (22).

9. The method according to claim 8, further characterized in that a CDS computer system is used to determine the interrelations between geometrical and technological parameters for the generator grinding.

10. The method according to any of claims 1 to 9, further characterized in that the surface on the cutting blade (22) is generated in step a) with at least one roughing cut and because at least a part of the generated surface is re-smeared in step b) with a finishing cut .

11. The method according to any of claims 1 to 10, further characterized in that the relative movement of translation between the grinding wheel (28) and the cutting blade (22) occurs when imparting an impulse or push movement. to the cutting blade (22) in relation to the grinding wheel (28).

12. The method according to claim 10, further characterized in that in the re-milling with a finishing cut, a pushing movement relative to the grinding wheel (28) is imparted to the cutting blade (22).

13. The method according to claim 10, further characterized in that an emery wheel (28) is used having the same specifications through its annular surface used for grinding and because the roughing and finishing cuts are selected only to through the choice of power parameters such as direction and speed of feeding, excessive measurement and speed of grinding.

14. The method according to claim 10 or 13, further characterized in that the roughing and finishing in steps a) and b), respectively, and in this way the surface elements of the annular surface used for grinding, are interchangeable.

15. The use of the method according to any of claims 1 to 14 which uses a diamond cup type grinding wheel (28) for grinding cemented carbide blades (22).

16. An emery wheel for carrying out the method according to any of claims 1 to 15, the grinding wheel (28) comprises a grinding wheel type diamond cup with a work area (34) having a part (34 ') located in a front area and a part (34") located in a cylindrical area of the cup-type grinding wheel, the work area (34) consists of an annular surface having a circular arc profile in section axial cross section extending over a total contact angle (GKW) and the grinding wheel has one and the same abrasive coating (32) throughout the working area (34), characterized in that the total contact angle (GWK) is of approximately 145 ° and because the circular arc profile has a radius of curvature (R) which is within a scale of 0.5 to 5 mm and preferably 0.5 to 1 mm 17.- The grinding wheel in accordance with the claim 16, characterized further by the emery wheel ( 28) has a fixed geometry and can not be revived. 18. The emery wheel according to claim 17, further characterized in that the grinding wheel (28) comprises a metal vehicle body (30) on which an abrasive coating (32) of diamond grain and a Galvanic union consisting of nickel, with the diamond grain protruding from the galvanic junction. 19. The grinding wheel according to claim 16, further characterized in that the emery wheel (28) can be revived. SUMMARY OF THE INVENTION An emery wheel that rotates about an axis and that has a work area consisting of an annular surface with a circular arc profile in axial cross section, is used to first generate a surface on a cutting blade when grinding with the The annular surface during a first orientation in space between the grinding wheel and the cutting blade by means of at least a first relative movement of translation between them, and subsequently at least a part of the generated surface is re-merged with the annular surface during a second orientation in space between the grinding wheel and the cutting blade by means of at least a second relative movement of translation between them. The grinding wheel is a grinding wheel type diamond cup. A part of the work area is located in a front area and another part is located in a cylindrical area of the grinding wheel. The first part is used for grinding by roughing and the other part is used to finish grinding the surface that will be generated in the cutting blade. The grinding wheel has the same abrasive coating for the entire work area. In this way, the roughing and finishing are carried out using areas of the wheel of emery that have the same specifications but different parameters of grinding. Preferably, the spatial orientation between the grinding wheel and the cutting blade is selected by adjusting the cutting blade relative to the grinding wheel. The method allows flat and / or concave surfaces to be generated in a cutting blade. MC / igp * pbg * aom * jtc * rcp * P00 / 1727F