Method for manufacturing a rolling tool, rolling tool, and method for producing a tooth portion by rolling using the rolling tool

Abstract

A method for manufacturing a rolling tool with cutting teeth is provided, the method including the steps of: determining a tooth profile to be formed using the rolling tool to create a tooth portion from a workpiece; determining a cutting tooth geometry including cutting edges of the cutting tooth geometry that can form the determined tooth profile formed from the workpiece by a rolling process; dividing the cutting tooth geometry into at least two different partial cutting tooth geometries, the different partial cutting tooth geometries being formed such that at least one of the partial cutting tooth geometries has a segment that recedes behind the outer contour of the cutting tooth geometry and such that an overlap between the different partial cutting tooth geometries reproduces the cutting tooth geometry; providing a rolling tool blank; and forming cutting teeth having the different partial cutting tooth geometries from the rolling tool blank. The method also includes the steps of a rolling tool and a method for creating a tooth portion using the rolling tool.

Description

Technical Field

[0001] The present invention relates to Rotary cutting a method for manufacturing a tool method .

Background Art

[0002] Rotary cutting Machining methods, in particular hobbing methods and skiving methods known from Patent Document 1, play an important role when producing tooth flanks by cutting. In this case, a series of cutting processes are carried out using a tool having cutting teeth, in which the cutting teeth each usually remove chips of the material of the workpiece blank, and tooth spaces are formed in the workpiece blank, whereby the tooth flanks are produced. In that case, for a given machining geometry, the shape of the cutting teeth of the tool, hereinafter referred to as the cutting tooth geometry, which is defined by the contour shape of the cutting edge, is predetermined by the shape of the tooth spaces formed in the workpiece blank. Rotary cutting Basically, in all machining methods, the achievable accuracy and the quality of the surface of the produced tooth flanks are affected by chip generation. So far, attempts have been made to optimize accuracy and quality, in particular by improving the cutting edges of the cutting teeth. For example, attempts have been made to use rounded cutting edges in order to minimize the action of uncontrolled forces on the cutting edge and to obtain a tool with an improved service life. However, in that case, it has been found that new problems arise, especially with regard to the exact positioning of the start of cutting of the cutting edge and the engaging cutting edge. The surface properties are not determined by the sliding up (Aufgleiten) of the cutting edge on the material to be cut and / or the "peeling off" of the material, and in addition, due to the "peeling off" and the pressing of the cutting edge against the material, associated adverse heat input and frictional losses occur. Rotary cutting The shape of the cutting teeth of the tool is predetermined by the shape of the tooth spaces formed in the workpiece blank.

[0003] Basically, all Rotary cutting In machining methods, the achievable accuracy and the quality of the surface of the produced tooth flanks are affected by chip generation. So far, attempts have been made to optimize accuracy and quality, in particular by improving the cutting edges of the cutting teeth. For example, attempts have been made to use rounded cutting edges in order to minimize the action of uncontrolled forces on the cutting edge and to obtain a tool with an improved service life. However, in that case, it has been found that new problems arise, especially with regard to the exact positioning of the start of cutting of the cutting edge and the engaging cutting edge. The surface properties are not determined by the sliding up (Aufgleiten) of the cutting edge on the material to be cut and / or the "peeling off" of the material, and in addition, due to the "peeling off" and the pressing of the cutting edge against the material, associated adverse heat input and frictional losses occur.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] Therefore, the object of the present invention is to improve the quality of the tooth part and Rotary cutting provide a method for manufacturing a tool. method That is what is to be provided.

[0006] The above object is solved by a method according to the present invention for manufacturing a tool having the features of claim 1, method and is thus solved. 。

[0007] equipped with cutting teeth. Rotary cutting The method according to the present invention for manufacturing a tool, in particular, already includes the steps that are necessary anyway, namely, - Rotary cutting a step of determining the tooth profile formed from the workpiece to be machined using the tool; - a step of determining a cutting tooth geometry including the cutting edge of the cutting tooth geometry that can be formed by a machining method for forming the defined tooth profile formed from the workpiece to be machined into a tooth part; Rotary cutting - a step of providing a tool blank; - Rotary cutting - a step of forming cutting teeth from the tool blank. - Rotary cutting This includes the step of forming cutting teeth from the tool blank. This is included.

[0008] What is important for the present invention is that the cutting tooth geometry is divided into at least two different partial cutting tooth geometries, and these different partial cutting tooth geometries are formed such that at least one of the partial cutting tooth geometries has a segment that retreats behind the outer contour of the cutting tooth geometry, and the overlap between the different partial cutting tooth geometries is formed to reproduce the cutting tooth geometry. Preferably, each of the partial cutting tooth geometries has these segments.

[0009] That is, each segment of the cutting edge of the cutting tooth geometry required to form a predetermined tooth space is a component of at least one partial cutting tooth geometry. Conversely, there is at least one partial cutting tooth geometry that does not have at least one of these segments. In each of the partial cutting tooth geometries, it is preferable that at least a part of the cutting edge of the cutting tooth geometry is missing.

[0010] That is, according to the prior art, a tooth space of a desired shape is introduced into the workpiece Rotary cutting The cutting edges of the cutting teeth of the same shape of the tool are, in the present invention, distributed among several cutting teeth, and at least one, preferably a plurality, of these cutting teeth have, in addition to one or more such cutting edge segments, further cutting edge segments located within the cutting tooth geometry whose contour is predefined by the cutting edge.

[0011] In that case, when forming the cutting teeth, cutting teeth having various partial cutting tooth geometries are Rotary cutting formed from a tool blank. That is, the tool manufactured according to the present invention Rotary cutting has cutting teeth of various shapes, and these cutting teeth are sequentially at least partially engaged with each other in order to form a tooth space together with the tooth profile defined when producing a tooth portion from the workpiece when machining the workpiece using this Rotary cutting tool. This can be ensured, for example, by adapting the ratio of the number of teeth of the tool to the tooth portion to be produced. In that case, material can be removed by cutting.

[0012] This can result in, in particular, when these cutting teeth interact with the workpiece at least several times, only a part of the already partially formed tooth profile of the tooth space formed respectively is subsequently machined, that is, material is removed only there. In this case, at least one segment of the tooth surface of the tooth space already partially formed from the workpiece has an unprocessed tooth profile after completion.

[0013] Intuitively, dividing the cutting tooth geometry into partial cutting tooth geometries might seem to increase the machining time. However, in fact, it has been found that this is not the case to a significant extent. That is, by doing so, on the one hand, the addition of the force required during cutting can be reduced by reducing the number or length of the tooth flanks of the tooth flank segments of the tool that interact with the workpiece being machined simultaneously, and on the other hand, a positive effect on the machining speed is exerted in that the chip flow characteristics can be improved. Rotary cutting that are interacted with the workpiece machined by the tool Rotary cutting By reducing the number or length of the tooth flanks of the tooth flank segments of the tool, on the one hand, the addition of the force required during cutting can be reduced, and on the other hand, a positive effect on the machining speed is exerted in that the chip flow characteristics can be improved.

[0014] At the same time, this procedure can result in a significant improvement in the quality of machining, especially with regard to the quality of the tooth flanks. According to the inventors' understanding, this is due to the changes in the chip generation process associated with this division.

[0015] The improvement in machining quality, especially tooth flank quality, is brought about by the division of the cutting tooth geometry into partial cutting tooth geometries affecting the engagement of the individual segments of the cutting edge as it enters the material and by enabling control of the chip thickness or the variation in chip thickness in different fragments of the chip.

[0016] To obtain a reliable prediction that results in an optimized partial cutting tooth geometry, the method preferably further includes the step of calculating the theoretical material removal when the cutting tooth interacts with a predetermined cutting tooth geometry and / or the partial cutting tooth geometry interacts with the workpiece.

[0017] In particular, for the tool manufactured according to the present invention Rotary cutting and the tool according to the present invention Rotary cutting do not use (at least) tooth flanks that can remove only very fine chips in (at least) one partial cutting tooth geometry, and thus, by adapting the partial cutting tooth geometry so that the cutting process performed by the cutting tooth having this partial cutting tooth geometry is skipped, it is possible to ensure that the removed chips have a minimum thickness at any location.

[0018] In practice, this can be achieved by not using the cutting edge or a segment of the cutting edge of the cutting tooth geometry in the partial cutting tooth geometry that results in theoretical material removal being below a predefined limit value when the cutting tooth geometry is divided into partial cutting tooth geometries.

[0019] According to a further advantageous embodiment of the method, cutting teeth having different partial cutting tooth geometries are Rotary cutting formed from a tool blank using a grinding wheel or a standard grinding wheel having a standardized profile, whereby different cutting tooth shapes can be machined / produced using the same grinding wheel, in particular in line machining (in zeilender Bearbeitung). This is cheaper than using a form grinding wheel, which was previously common, and which was individually produced for each cutting tooth shape. In addition, it enables easy individualization of cutting teeth having various partial cutting tooth geometries.

[0020] Rotary cutting machining A tool according to the invention for producing a toothed portion on a workpiece to be machined by forming a tooth shape by a method Rotary cutting is Rotary cutting characterized in that the tool comprises cutting teeth having at least two different partial cutting tooth geometries, the partial cutting tooth geometries together forming a cutting tooth geometry including the cutting edges of the cutting tooth geometry that can form a defined tooth shape to be formed from the workpiece to be machined by a method, and the different partial cutting tooth geometries are formed such that when at least one cutting tooth having one of the partial cutting tooth geometries interacts with the workpiece to be machined, only a part (Untermenge) of the cutting edge of the cutting tooth geometry interacts with the workpiece to be machined. Rotary cutting machining It is particularly preferred that the different partial cutting geometries are formed such that when the cutting teeth having the respective partial cutting tooth geometries interact with the workpiece to be machined, only a part of the cutting edge of the cutting tooth geometry interacts with the workpiece to be machined.

[0021] It is particularly preferred that the different partial cutting geometries are formed such that when the cutting teeth having the respective partial cutting tooth geometries interact with the workpiece to be machined, only a part of the cutting edge of the cutting tooth geometry interacts with the workpiece to be machined.

[0022] Such Rotary cuttingUsing a tool Rotary cutting In the method according to the invention for producing a toothed portion on a workpiece to be machined by forming a tooth profile by machining using a tool, when sequentially forming a predetermined gap between two teeth of the tooth profile, having different partial cutting tooth geometries Rotary cutting characterized in that the cutting teeth of the tool are sequentially used. This can be done, in particular, by adapting them when the number of teeth of the toothed portion and Rotary cutting the tool is appropriately selected.

[0023] The present invention will be described in detail below based on the drawings showing embodiments.

Brief Description of the Drawings

[0024]

Figure 1a

Figure 1b

Figure 2a

Figure 2b

Figure 3a

Figure 3b

Figure 4a

Figure 4b

Figure 5a

Figure 5b

DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1a shows, on the left side, a workpiece 1 having external teeth that have already been fully introduced into the workpiece 1 by forming tooth spaces 1a, and on the right side, a Rotary cutting tool 100 having a plurality of identical cutting teeth 101, the cutting tooth geometry of these cutting teeth being defined by the contour line of the cutting edge. As clearly recognized in FIG. 1, despite the cutting teeth 101 being significantly narrower than the tooth spaces 1a, the fact that the cutting teeth can introduce the tooth spaces 1a into the workpiece 1 is a Rotary cutting result typical of the Rotary cutting machining method of the operation of the tool 100 on the workpiece 1.

[0026] FIG. 1b shows, on the right side, a workpiece 2 having internal teeth that have already been fully introduced into the workpiece 2 by forming tooth spaces 2a, and on the right side, a Rotary cutting tool 200 having a plurality of identical cutting teeth 201, the cutting tooth geometry of these cutting teeth being defined by the contour line of the cutting edge. As recognized from the comparison between FIG. 1a and FIG. 1b, the radius ratio of the internal teeth and Rotary cutting tool 2 is significantly more similar than that of the external teeth and Rotary cutting tool 1, whereby the width of the cutting teeth 201 is significantly more similar to the width of the tooth spaces 2a.

[0027] FIG. 2a or FIG. 2b each shows a prior art Rotary cuttingA series of intermediate states when introducing tooth portions into the workpiece according to Fig. 1a or Fig. 1b using a tool is (shown). These illustrations are each greatly enlarged, and in the simulations shown here, the formation of a tooth gap with a total depth of 4 mm realized by a series of about 80 cuttings is shown respectively.

[0028] In that case, in Fig. 2a, the tooth gap is gradually cut from right to left, whereby cutting line 11 is formed on a part of the workpiece surface after the cutting that removes the first material, and cutting line 12 etc. are formed after the cutting that removes the second material. In Fig. 2b, the tooth gap is gradually cut from left to right, whereby cutting line 21 is formed on a part of the workpiece surface after the cutting that removes the first material, and cutting line 22 etc. are formed after the cutting that removes the second material.

[0029] Therefore, the regions between two adjacent cutting lines each show the teeth that result from the next cutting following in the direction of the tooth bottom of the tooth gap, in their "ideal shape", i.e., the teeth that are not affected by the chips while the chips are being removed. It is recognized that there are a plurality of very closely arranged cutting lines in both the case of the external tooth cut shown in Fig. 2a and the case of the internal tooth cut shown in Fig. 2b. Accordingly, from Fig. 2a and Fig. 2b, as is known from the prior art Rotary cutting When producing a tooth gap using a tool, a large number of chips are generated. The chips have very fine fragments and are thus easily deformed during cutting, while being removed indeterminately, which results in quasi-optimal chip generation and, as a result, quasi-optimal tooth portion quality.

[0030] Figs. 3a and 3b show an example for dividing the cutting tooth geometry 30 for forming external teeth into two partial cutting tooth geometries 31, 32 according to the present invention. In this example, the corresponding Rotary cuttingThe tool has only cutting teeth whose cutting edges each include one of the partial cutting tooth geometries 31, 32, and these cutting teeth are arranged such that successive cutting is performed using cutting teeth with different partial cutting tooth geometries. Of course, if it is clear that this is meaningful, it is also possible to perform further division into more partial cutting tooth geometries. In addition, as is particularly recognized in FIGS. 2a and 2b, since the first chip to be removed still does not have the problem of fine chip fragments, the cutting edges can be Rotary cutting provided on the tool for cutting teeth corresponding to the cutting tooth geometry.

[0031] In FIG. 3a, the cutting tooth geometry 30, the partial cutting tooth geometry 31, and the partial cutting tooth geometry 32 are each shown offset from each other by a certain offset. As already recognized in this figure, the partial cutting tooth geometry 31 is created by shortening the cutting tooth geometry 30 by its tip portion but has the side surface of the cutting tooth geometry, while the partial cutting tooth geometry 32 reproduces the tip of the cutting tooth geometry 30 but has a narrower side surface area.

[0032] As recognized in FIG. 3b where the partial cutting tooth geometries 31, 32 are shown overlapping each other, the partial cutting tooth geometries 31 and 32 together reproduce the cutting tooth geometry 30 corresponding to the outer contour of the overlapping partial cutting tooth geometries 31 and 32. The segments 31a and 31c of the partial cutting tooth geometry 31 form the side surfaces of the cutting tooth geometry 30, and the segment 32b of the partial cutting tooth geometry 32 forms the tip of the cutting tooth geometry 30.

[0033] Therefore, conversely, the partial cutting tooth geometry 31 has a segment 31b that retreats behind the cutting tooth geometry 30, and the partial cutting tooth geometry 32 has segments 32a, 32c that retreat behind the cutting tooth geometry 30.

[0034] Figures 4a and 4b show a similar situation for each of the cutting tooth geometries 40 introducing internal teeth and the associated partial cutting tooth geometries 41 and 42 having segments 41a, 41b, 41c or 42a, 42b, 42c, and in this regard, reference can be made to the description of Figures 3a and 3b where the reference signs are respectively adapted.

[0035] However, it should be clearly emphasized that another division into two or more partial cutting tooth geometries 31, 32, 41, 42 of the cutting tooth geometries 30, 40 is also possible, and it is not necessary for one partial cutting tooth geometry to necessarily reproduce the tip and the second partial cutting tooth geometry to reproduce the flank of the cutting tooth geometry.

[0036] The effect of this measure is recognized in Figures 5a and 5b, which show a series of intermediate states represented by the cutting lines 51, 52, 61, 62 when introducing external or internal teeth into the workpieces 1 or 2, as in Figures 2a and 2b. However, different from Figures 2a and 2b, here, in the illustrated examples, the cutting teeth having the partial cutting tooth geometry 31 or 41 and the cutting teeth having the partial cutting tooth geometry 32 or 42 are used alternately Rotary cutting arranged on the tool and having different types of each cutting tooth including the partial cutting tooth geometries 31, 32 or 41, 42 Rotary cutting are machined using the tool. In that case, the total depth and feed of the tooth part are the same as those in Figures 2a or 2b.

[0037] It can be immediately recognized here that the areas where only very fine chips are removed are significantly reduced. In these areas, a definite chip generation can be predicted, which brings about a significantly higher quality of the tooth part.

Description of the reference signs

[0038] 1, 2... workpieces 100, 200... Rotary cutting tools 101, 201... cutting teeth 1a, 2a... tooth spaces 11, 12, 21, 22, 51, 52, 61, 62... cutting lines 30, 40... cutting tooth geometry 31, 32, 41, 42... partial cutting tooth geometry 31a, 31b, 31c, 32a, 32b, 32c... segments of partial cutting tooth geometry 41a, 41b, 41c, 42a, 42b, 42c... segments of partial cutting tooth geometry

Claims

【Claim 1】 A method for manufacturing a rotary cutting tool (100, 200) provided with cutting teeth (101, 201), comprising: - determining a tooth profile formed for producing a tooth portion from a workpiece (1, 2) using the rotary cutting tool (100, 200); - determining the cutting tooth geometry (30, 40) including the cutting edges of the cutting tooth geometry (30, 40) that can form the determined tooth profile from the workpiece (1, 2) by a rotary cutting method; - a step of dividing the cutting tooth geometry (30, 40) into at least two different partial cutting tooth geometries (31, 32, 41, 42), wherein the different partial cutting tooth geometries (31, 32, 41, 42) are formed such that at least one of the partial cutting tooth geometries (31, 32, 41, 42) has a segment (31b, 32a, 32c, 41b, 32a, 32c) located inside the contour of the cutting tooth geometry (30, 40), and the overlap between the different partial cutting tooth geometries (31, 32, 41, 42) reproduces the cutting tooth geometry (30, 40); - providing a rotary cutting tool blank; - forming cutting teeth (101, 201) having the different partial cutting tooth geometries (31, 32, 41, 41) from the rotary cutting tool blank; - calculating the size of the material theoretically removed when the cutting teeth (101, 201) having a predetermined cutting tooth geometry (30, 40) and / or a predetermined partial cutting tooth geometry (31, 32, 41, 42) interact with the workpiece (1, 2); A method, when dividing the cutting tooth geometry (30, 40) into the partial cutting tooth geometries (31, 32, 41, 42), of positioning at least one segment of the partial cutting tooth geometry (31, 32, 41, 42) corresponding to a segment of the cutting tooth geometry (30, 40) where the size of the material theoretically removed when interacting with the workpiece (1, 2) is less than a predetermined limit value but greater than zero, inside the contour of the cutting tooth geometry.

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