Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
  • B24B5/18—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centreless means for supporting, guiding, floating or rotating work
  • B24B5/30—Regulating-wheels; Equipment therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
  • B24B5/18—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centreless means for supporting, guiding, floating or rotating work
  • B24B5/22—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centreless means for supporting, guiding, floating or rotating work for grinding cylindrical surfaces, e.g. on bolts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
  • B24B5/18—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centreless means for supporting, guiding, floating or rotating work
  • B24B5/24—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centreless means for supporting, guiding, floating or rotating work for grinding conical surfaces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
  • B24B5/18—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centreless means for supporting, guiding, floating or rotating work
  • B24B5/28—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centreless means for supporting, guiding, floating or rotating work for grinding outer surfaces concentrically to bores, involving additional centering means

Definitions

• the invention relates to a method for centerless grinding of shaft parts, in particular of tubes for built camshafts and a provided for performing the method grinding wheel and regulating wheel pair in a centerless grinding machine, the shaft parts to the workpiece longitudinal axis concentrically extending end Zentrierboh- ments have.
• the workpiece between the grinding wheel and regulating wheel is ground resting and rotating on a support ruler.
• Regulating wheel and grinding wheel thereby form a grinding gap which is closed downwards by the support ruler so that the wave-shaped workpiece is enclosed by a linear contact with the regulating wheel, the grinding wheel and the support surface of the support ruler and is thus fixed in position with respect to its longitudinal axis and rotates.
• the aim of this arrangement is a quiet as possible position despite rotation and runout of the rough blank.
• the blank to be ground is subject to pre-processing before it is finish-machined. After preprocessing, the blank has dimensional errors, in particular straightness errors or rounding errors.
• the workpiece is first ground at the location of the highest concentricity impact. Because of such form errors, the workpiece does not lie exactly on the support ruler during grinding. Only after the complete grinding of the workpiece will this rest in the grinding gap substantially full length on the support ruler and can - if at all - now defined and cut to size and shape.
• centering is introduced on each end face of the workpiece to be ground, which is also referred to as the center. This centering is intended to define the longitudinal axis of the finished workpiece, to which the intermediate and finish machining subsequent to the pre-processing should relate.
• the workpiece enters a prismatic groove through a linear contact present on each leg of the support prism and is held in the middle region by means of a pinch roller and pressed into the prism.
• the known grinding method describes the grinding of two pin-like end portions of the workpiece.
• the pins can only have sufficient concentricity if the workpiece has previously been ground exactly concentric, d. H. just can not be left in its rough contour.
• the pins present in the end area are ground by means of a grinding wheel without an abutment on the side opposite the grinding wheel. The concentricity accuracy required today can not be achieved with such a method.
• a workpiece holder for a centerless grinding of cylindrical parts in which in a known manner a grinding gap is defined by a grinding wheel, control disk and a support ruler.
• a very long cylindrical rod body is ground by passage grinding.
• the support is mounted hydrodynamically on the support ruler by pockets or nozzles arranged there, which are acted upon by a pressure medium.
• the pressure is controlled in dependence on the load during the respective grinding phase.
• DE 10 2010 010 758 A1 describes a method for centerless cylindrical grinding of rod-shaped workpieces and a centerless cylindrical grinding machine for grinding such workpieces.
• the individual grinding wheels are arranged so that the grinding gap gradually becomes narrower in the direction of the exit from the grinding device.
• the cylindrical outer contour is thus ground through a peel grinding through the respective individual grinding wheels.
• the width of the Reef discs and the grinding wheels is significantly less than the length of the workpiece to be ground in this known cylindrical grinding machine.
• a targeted grinding takes place by means of a pre-centering device, which is arranged in the direction of passage of the workpiece to be ground at the entrance.
• a concentric grinding of end regions for the purpose of centering the blank with respect to the centers is not described in this known method. Rather, a support disk is provided at the entrance and at the exit of the device, which serve the balance of forces because of the offset arranged and thus unevenly acting grinding wheels.
• the width of the regulating wheel is greater than the width of the grinding wheel and that on the other hand, the respective spindle for the regulating wheels and for the grinding wheels are dimensioned strong and a small axial gap between the Overlap areas of regulating wheel and grinding wheel must be realized.
• Mikrosa is known as a manufacturer of centerless grinding wheels. It uses a method in which the workpiece is ground between so-called auxiliary tips and then, after loosening the tips, the workpiece is finish-ground in the same grinding station centerless on a support rail between the grinding wheel and the regulating wheel. Both the technical structure and the alignment of the tips require a relatively large effort, and the complete system is difficult to control bar in terms of accuracy bar.
• the object of the present invention is to provide a method for centerless grinding of shaft parts, in particular of tubes for built camshafts, and a pair of grinding wheel and regulating wheel, taking into account the geometry of the shaft parts to be ground for performing the method, with which Deformation of a Wellenrohteils from the pre-machining effect to a much lesser extent on the accuracy of the finished shaft part, as is the case with known methods, therefore, therefore, a higher accuracy of the finished ground shaft part can be achieved.
• camshaft tubes are to be ground so that only a minimal concentricity error occurs, namely, such a high concentricity should be achieved, which can not be achieved with known centerless grinding methods.
• the basic idea on which the present invention is based is that the base part to be ground is first sanded at its ends in the centerless grinding process, without the grinding and regulating disks already grinding at the points of the highest concentricity of the wave-shaped part.
• This makes it possible for the corrugated part to be ground first in the area in which centering is found. This ensures that the grinding zones of the shaft part are located exactly above the center, d. H. the respective centering at the ends of the shaft part, so that with respect to the respective center a centric grinding of the shaft part can be achieved, so that at the ends of the shaft part, a high concentricity of the shaft part is achieved.
• the grinding wheel and the regulating wheel have a radial distance from one another in the radial direction in the region of the ends of the shaft part, which is smaller than in the area between the end regions of the shaft part, ie in the so-called intermediate region.
• the required for grinding the shaft part grinding gap is thus - seen in the axial direction of the grinding wheel and the regulating wheel - defined between the grinding wheel and the regulating wheel and is bounded below by a support ruler.
• the distance between the grinding wheel and the regulating wheel in the radial direction is less in the region of the ends of the shaft part than the distance in the intermediate region between the end regions of the shaft part.
• the end portions of the shaft part are first ground. This is followed by the sanding of the intermediate region between the end regions, followed by a dimensionally and form-wise grinding of the entire shaft part to final dimension, on the basis of the polished contours on the end regions of the bearing surface concentric with the centerings shaft part.
• the dimensionally and form-containing grinding of the entire shaft part joins, which on the basis of concentric to the centerings executed polished sections at the end portions of the Weilenteils even with normally always existing rounding at elongated wavy components thereby to a higher Concentricity leads to the centerings at the end areas, as is the case with conventional centerless grinding.
• Radial distance between the grinding wheel and the regulating wheel is not necessarily the smallest distance in the radial direction between the regulating wheel and the grinding wheel understood, but a distance above and below both longitudinal axes of the grinding wheel and the regulating wheel having plane in which the wave-shaped Workpiece is arranged and held down by the support ruler in the grinding gap.
• the geometric relationships for such Centerless loops are shown in a basic arrangement in Fig. 7.
• the position of the plane above or below is defined by whether it is ground above or below the center.
• the grinding wheel and the regulating wheel are designed such that they have on their sides, which during grinding of the shaft part, the end part thereof. Chen correspond, are profiled and have a larger diameter than in the lying between the end regions intermediate area. Due to the respective larger diameter in the areas corresponding to the end portions of the shaft part, a smaller distance between grinding wheel and regulating wheel is present than in the intermediate region, so that during grinding first the end portions of the shaft part are ground.
• the areas of larger diameter of the grinding wheel and the regulating wheel in this case have such a diameter that in fact first the end portions are ground on the shaft portion before the grinding wheel and the regulating wheel in the region of the largest rounding of the shaft part engages with this.
• the polished sections are produced concentrically with the axial centering of the shaft part and serve as a basis for the subsequent dimensional and shape-based grinding. This achieves an improved grinding result on the workpiece.
• the shaft portion used in centerless grinding according to the invention each have an area of increased diameter, preferably in the form of a collar in its end regions, which also first to the ground portions of the shaft portion with improved concentricity to the axial centerings are produced.
• this is only achieved if the region of increased diameter has a diameter such that initially the engagement of the grinding wheel and the regulating wheel takes place only on the polished sections on the end regions of the shaft part, without grinding already in the region of the greatest rounding error of the shaft part.
• the grinding wheel and the regulating wheel in their areas corresponding to the intermediate areas of the shaft part have such diameters that the end areas of the shaft part are first ground.
• shaft parts with a certain greater length are provided according to a further exemplary embodiment in that the grinding wheel and the regulating wheel are located in the intermediate region between the end regions of the shaft part, in particular the center, a region of larger diameter, by means of which in addition to the polished sections at the end regions a likewise concentric to the centering support seat is ground to the shaft part.
• this supporting seat to be ground is arranged in the region of the maximum rounding error of the shaft part.
• This support seat is preferably ground by the fact that the grinding wheel and the regulating wheel each have an area of increased diameter in this area.
• the shaft part itself may preferably have an area of increased diameter in its middle region or intermediate region, which first either coincides with the grinding process the end portions or after this comes into contact with the grinding wheel in the regulating wheel.
• the dimensioning of the distance ie the profiling of grinding and regulating wheel or the dimensions of the shaft part, either at the end regions of the shaft part or in its middle region is designed so that this distance is so small that initially a grinding on the End areas and only then a grinding in the region of the largest concentricity of the shaft part takes place, which is preferably possible even in the presence of a arranged between the end regions support seat.
• the grinding wheel and the regulating wheel in the intermediate region, which lies between the end regions of the shaft part to be ground are profiled to a small extent.
• This low profiling includes such a number of respective grooves in both the grinding wheel and the regulating wheel as seats on components, in particular cams, are needed on the finished shaft part.
• Such cam seats do not constitute support seats in the sense of the present invention and only have a small increase in diameter of, for example, approximately 0.02-0.05 mm relative to the remaining area of the camshaft part.
• a cam seats for mounting of respective cam-exhibiting shaft part is otherwise centered also ground according to the method of the invention, so that compared to the ground with known centerless loops shaft part has an increased, ie improved concentricity to the axial centerings.
• This higher accuracy of the concentricity of the camshaft stressess leads to improved running and operating conditions of the finished assembled camshaft in the respective engines.
• a pair of grinding wheels and a pair of washers used in a centerless grinding machine for carrying out the method according to the invention and having such a profiling that on each side of the grinding wheel and the regulating wheel, which face each other , an area of larger diameter is present, so that there is a respective radial distance between the grinding wheel and the regulating wheel, which is smaller than in an area between these thus profiled areas of the grinding wheel and the regulating wheel, d. H. in an intermediate area.
• Fig. 1 shows a basic arrangement of grinding wheel and regulating wheel with a
• FIG. 2 shows an arrangement as in FIG. 1, but with an additional profiling in the intermediate region between the end regions for producing a further grinding surface serving for a supporting seat, which has not yet come into contact with the shaft part in the region of the largest rounding;
• FIG. 3 shows an arrangement according to FIG. 2, in which the contact with the grinding wheel has just occurred in the region of the greatest rounding error of the shaft part;
• FIG. 4 shows an exemplary embodiment in which the grinding wheel and regulating wheel have a substantially constant diameter, but the shaft part has in each case at its end regions an area of increased diameter which is provided for a bevel according to the invention
• Fig. 5 shows an embodiment of FIG. 4, in which by means of grinding wheel and regulating wheel in the respective end region of the shaft part in there existing, larger diameter of the shaft part, the polished section, wherein additionally in the region of the largest rounding error, a region of increased diameter on the workpiece is present, which is provided for the production of a bevel for a support seat;
• FIG. 6 shows the embodiment according to FIG. 5, wherein, however, the area of enlarged diameter provided on the workpiece for the support seat is also just ground;
• FIG. 1 to 6 show a basic arrangement in plan view in an arrangement of the workpiece between the grinding wheel 1 and the regulating wheel 2 in a section through the cutting planes 27 of FIG. 7.
• a shaft portion 9 is disposed between the grinding wheel 1 and the regulating wheel 2, which has a curvature in exaggerated representation, so that in the central region of a maximum rounding error is present.
• Both the grinding wheel 1 and the regulating wheel 2 have at their lateral end portions profilings 3 and 4, which areas of larger diameter 5 of the grinding wheel 1 and larger diameter 6 of the regulating wheel 2 have.
• the diameters of the regions of increased diameter 5, 6 are dimensioned so that with them at the end portions of the base part 9, to which at the respective end faces centerings 11 are introduced, a bevel occurs before the grinding wheel 1 and the regulating wheel 2 in the region of the largest Rounding the shaft part 9 come into contact with this.
• a to be grounded shaft part 9 which additionally has a collar, which also in this centerless grinding process is grinded from the outer diameter.
• a corresponding groove is provided in the grinding wheel 1 and also in the regulating wheel 2.
• the profiled areas 3, 4 of the grinding wheel 1 and the regulating wheel 2 according to FIGS. 2 to 6 are identical in their dimensioning to the embodiment according to FIG. 1.
• the grinding wheel 1 and the regulating wheel 2 approximately in the region of the maximum rounding error of the shaft part to be ground has an additional profiling 30 which forms a distance 13 for a supporting seat 15 to be ground (see FIG.
• FIG. 3 the embodiment of FIG. 2 is shown, but wherein the profiling 30 in
• Fig. 4 shows a further embodiment according to the invention, in which the grinding wheel 1 and the regulating wheel 2 with respect.
• the dimensional and Formhaltigkelt of the shaft part 9 have substantial areas of constant diameter.
• Both the grinding wheel 1 and the control disk 2 thus have, except for the collar 12 on the base part 9 no profiling in their edge regions. Rather, the shaft part 9 is formed so that it at its end regions in each case a collar, d. H. Has areas of larger diameter.
• the workpiece 9 is also shown in an exaggerated manner with a curvature having an approximately in its center existing maximum rounding error.
• the grinding wheel 1 and the regulating wheel 2 are not yet in engagement with the shaft part 9 in the situation illustrated in FIG. 4.
• the procedure according to the invention initially takes place at the area of the collar, d. H. at the end regions of the base part 9, because there the distance between the grinding wheel 1 and the control disk 2 is less than in the intermediate region, even in the region of the greatest rounding error of the shaft part 9.
• FIG. 5 shows a further exemplary embodiment in which a section is made by the region of increased diameter, ie the collar 14, in the end region of the workpiece 9, wherein the situation is precisely the engagement of grinding wheel 1 and regulating wheel 2.
• an area of increased diameter 31 is provided on the shaft part, ie a further collar which is suitable for the Grinding an additional support seat is provided.
• Such an additional support seat is useful above all when certain larger lengths of the workpiece, ie the Wellenteiis are present.
• the area provided for the supporting seat is not yet ground. Only when a sufficiently strong bevel has taken place in the end regions of the base part 9 will the grinding wheel 1 and the regulating wheel 2 come into engagement with the middle collar on the workpiece for grinding a supporting seat.
• FIG. 6 This situation is illustrated in FIG. 6, which otherwise corresponds in its details to the representation according to FIG. 5.
• Fig. 7 in side view, d. H. in a view in the direction of the longitudinal axes of the grinding wheel 1 and the regulating wheel 2, the arrangement of the distance between the grinding wheel and the regulating wheel including the arrangement of the Welieseils 9 at this distance, d. H. in the grinding gap in conjunction with the support ruler 16 shown.
• the wave-shaped part or the Weilenteil 9 is moved by engagement of the grinding wheel 1, which is driven in the direction of rotation 21 about its longitudinal axis 19 when resting on the support surface 24 of the support ruler 6 in the direction of rotation 23.
• the regulating wheel 2 is also in its direction of rotation 22 in engagement with the shaft part 9 and thereby supports its rotation and forms together with the support surface 24 of the support ruler an abutment for introducing the grinding forces from the grinding wheel 1.
• the grinding wheel 1 rotates about its axis of rotation 17 and the regulating wheel 2 about its axis of rotation 18.
• the grinding wheel 1 is delivered in the feed direction 25, wherein the feed direction of the regulating wheel is characterized by the double arrow 26. Under delivery direction in each case a positive or negative feed direction is characterized, which is represented by the respective double arrows 25 and 26 respectively.
• the reference numeral 27 is the
• the method according to the invention and the grinding wheel and regulating wheel pair present for realizing the method it is possible to produce a higher concentricity of a wave-shaped part relative to the axial centering provided on the end regions.
• Both the method and the pair of grinding wheels and regulating wheels prevent according to the invention that the rounding error which is always present in the case of shaft parts has a negative effect on the concentricity or concentricity of the finished component.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Grinding Of Cylindrical And Plane Surfaces (AREA)
• Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)

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• 2013
  • 2013-07-19 DE DE102013214226.9A patent/DE102013214226B4/de active Active
• 2014
  • 2014-06-16 ES ES14731228T patent/ES2765207T3/es active Active
  • 2014-06-16 US US14/903,202 patent/US9878417B2/en active Active
  • 2014-06-16 EP EP14731228.4A patent/EP3022014B1/fr active Active
  • 2014-06-16 CN CN201480040728.5A patent/CN105392596B/zh active Active
  • 2014-06-16 RU RU2016102744A patent/RU2660943C2/ru active
  • 2014-06-16 WO PCT/EP2014/062525 patent/WO2015007444A1/fr not_active Ceased

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