EP1312446A2 - Diamond form dressing roller and manufacturing method - Google Patents

Abstract

The roller (10) to dress diamond grinding disks, in a ceramic or metal or synthetic resin bonding, has a metal carrier body (12). It has a cladding (14) in at least one layer, and the separate diamond fragments are of sizes within very tight tolerances, arranged on a plane at right angles to the rotary axis of the roller. The diamonds are laid out in a pattern so that, as the grinding disk wears, the grinding action remains constant. The diamonds are laid in their patterns with an adhesive layer, on a ring-shaped underlay which can be melted away. The bonding powder is added, and the material is compressed while cold, to be sintered. The shaped ring cladding is ground around the circumference.

Description

The invention relates to a diamond dressing roll for dressing Diamond grinding wheels in ceramic, bakelitic or metallic bond according to claim 1.

Grinding disks are used to grind profiles into workpiece surfaces used, which have geometrically defined profiles on their grinding surface. These profiles must first be worked into a new wheel by dressing and then because of the grinding wheel wear of Reworked from time to time. Grinding wheel wear can both impermissible profile deviations also lead to inadequate grinding behavior, where the grinding forces, the temperature of the workpiece surface and / or the surface roughness get out of tolerance.

A profile grinding wheel is often dressed either with a profile dressing roller or a diamond dressing roll. A profile dressing roll is open the workpiece contour. This is in contrast to a diamond dressing roll, the required with a CNC control of the grinding machine Profile is controlled accordingly. For CNC controlled Dressing conventional Have grinding wheels with abrasives made of corundum or silicon carbide diamond form dressing rolls have proven their worth, with one layer on their surrounding area Wear diamonds. This diamond layer can consist of a diamond grain in one Binding consist of electrodeposited nickel or also of polycrystalline Diamond aggregates on the surface of the form dressing roll by a galvanically or chemically deposited nickel deposit or by an in sintered metal applied in a sintering process can be held.

In some cases, very small concave radii have to be introduced into the surface of the grinding wheel to achieve very small corner radii on the workpiece, e.g. 0.2 or 0.1 mm. For this purpose, dressing rolls are ground in their largest diameter, so that a convex radius with a corresponding diameter is created. The wear on the form dressing roller caused by dressing these fine edges is naturally high. If the wear exceeds the profile tolerance, must the form dressing roll is reground or renewed.

Wear is when dressing grinding wheels with cubic crystalline boron nitride on a diamond form dressing roll so large that the economy of the entire grinding process with CBN grinding wheels is in question. From EP 0 116 668 B1 a form dressing roll has become known that this problem by a perpendicular to the axis of rotation of the dressing roller multilayer diamond coating and in Single-layer diamond coating loosens in the direction of the axis of rotation. The diamond coating forms a profile perpendicular to the axis of rotation, that with constant dressing conditions self-generated and thus allows a larger amount of wear without the Profile out of tolerance. With the well-known form dressing roller fine profiles can be achieved by choosing a finer grain.

Dressing consists of profiling and sharpening the grinding wheel together. Profiling is required to get the profile of the grinding wheel into the to bring back the desired shape and tolerance. The sharpening takes place around in addition to restore the grinding ability of the grinding wheel, i.e. the Grinding forces, the heat development and the surface roughness generated on Bring the workpiece back into the required limits.

With conventional grinding wheels, both requirements can be met by one Accomplish the process. With CBN grinding wheels, the profiling and Sharpening can be done one after the other because of the lower difference in hardness between diamond and CBN in conventional profiling with a grinding surface insufficient grinding properties caused by insufficient grain protrusion above the bond level and thus characterized by insufficient chip space is. Only after the so-called touch dressing process was developed Dressing deliveries can be realized that are only a few micrometers and in which the dressing process does not destroy the grain protrusion over the bond.

The invention has for its object to provide a diamond form dressing roll, with which the profiling and sharpening of diamond grinding wheels in one Gear possible and the wear of the form dressing roll is so low that even long Profile trains dressed on a diamond grinding wheel with great profile accuracy can be.

This object is achieved by the features of patent claim 1.

In the form dressing roll according to the invention, the covering consists of at least one Layer of closely sized diamonds, using the setting scheme according to which Diamond grains are set, is selected so that the peripheral geometry in the progress of wear remains approximately constant. This is e.g. the case when the Diamond grains e.g. placed along a spiral, the center of which is on the The axis of rotation of the dressing roller lies.

In the form dressing roll according to the invention, the covering can also have at least two Have layers of narrowly sized diamond grains. In every shift the diamond grains are approximately in a plane perpendicular to the axis of rotation of the Dressing roller arranged according to a predetermined setting scheme. In the betting scheme, the diamond grains are shown in more detail below Spaced from each other. The neighboring layers are like this arranged that the diamond grains of one layer in gaps of the diamond grains the other layer are arranged and partially protrude into the other layer. The layers are thus interlocked or interlaced, so that the Viewed in the axial direction, the thickness of the abrasive coating is less than the sum of the Grain diameter. If one speaks of layers here, then it should cannot be expressed that separate layers are produced from the outset must be made with a plane of diamond grains perpendicular to each Axis of rotation, although this is a convenient manufacturing method; much more the primary purpose is to demonstrate the geometric structure of the covering. The setting scheme after the individual diamond grains of narrowly sized are set is such that the surface geometry of the form dressing roll in Wear progress remains almost constant.

The form dressing roller according to the invention results in a wider diamond coating than in the known form dressing roll mentioned above, the grain sizes so be chosen so that natural radii arise at the edges of the coverings generate themselves and the smallest given concave radius at the Correspond to grinding wheel.

The width of a covering from a "layer" corresponds to the grain size, if the Covering is not ground down to a smaller width. The width of one According to one embodiment of the invention, the covering of two layers is e.g. one and a half times the grain size. With four layers this gives a width of three grain sizes.

Various setting schemes are conceivable to implement the teaching of claim 1. According to one embodiment of the invention, one provides that the setting scheme with at least one spiral or several geometrically identical spirals has a common center, the largest diameter in the circumferential direction are offset by an equal angle and along which the diamond grains are set, with the center on the axis of rotation of the form dressing roller lies. If two layers are produced according to this setting scheme and then composed, is a corresponding angular rotation of the layers to each other required to the mentioned entanglement of the diamond grain arrangements to ensure.

In another embodiment of the invention, the diamond dressing roll is made from dressing plates arranged radially on their circumference, which together are connected by a metallic bond which is easy to sand. For this, e.g. sintered cobalt can be used. In the individual, e.g. Rectangle Platelets are again at least two layers of diamond grain arrangements provided, with a predetermined setting scheme in each layer is realized and the diamond grains of neighboring layers in gaps of diamond grains are arranged in the other layer and the layers partially interlocking to achieve the goal of a wear-independent orbital geometry to obtain. Since the edge radii of the form roller in turn only from defined diamonds at defined points can also be created with this Dress defined radii.

A bond is preferred for a form dressing roll according to the invention galvanic or sintered bond with high tungsten content used. The Grain size is equal to or less than 1.5 mm, and the length of the abrasive coating in the feed direction is preferably between 5 and 10 mm.

• Setzen der Diamantkörner nach dem vorgegebenen Setzschema auf eine ringförmige schmelzbare Unterlage, vorzugsweise mit Klebschicht,
• Zugabe von Bindungspulver,
• Kaltpressen des Materials,
• Sintern und
• Umfangsschleifen des so hergestellten ringförmigen Belags.

Various methods are conceivable for producing a form dressing roll according to the invention. An inventive method comprises the following steps:

• Placing the diamond grains on an annular fusible base, preferably with an adhesive layer, in accordance with the specified setting scheme,
• Adding binding powder,
• Cold pressing the material,
• Sintering and
• Circumferential grinding of the annular covering thus produced.

Instead of the adhesive, the base can also have holes that after the Placement scheme are arranged, e.g. a spiral and each take up a diamond grain. If there are several layers, these are prepared and stacked separately, possibly with relative displacement or rotation, after which the stack is cold pressed. Subsequently, if necessary, grinding or finishing of the thus produced takes place Form dressing role.

Fig. 1

zeigt die Seitenansicht einer Formabrichtrolle nach der Erfindung in schematischer Darstellung.

Fig. 2

zeigt eine Ausschnittsvergrößerung der Formabrichtrolle nach Fig. 1.

Fig. 3

zeigt schematisch einen Teil eines Radialschnitts durch die Formabrichtrolle nach Fig. 1.

Fig. 4

zeigt die Draufsicht auf ein Teil der Formabrichtrolle nach Fig. 3.

Fig. 5

zeigt schematisch ein Setzschema für Diamantkörner einer Schicht einer Formabrichtrolle nach den Figuren 1 bis 4.

Fig. 6

zeigt das Setzschema einer Formabrichtrolle mit zwei Schichten gemäß Fig. 5.

Fig. 7

zeigt schematisch eine andere Ausführungsform einer Abrichtrolle nach der Erfindung.

Fig. 8

zeigt in Draufsicht eine erste Schicht eines Plättchens der Abrichtrolle nach Fig. 7.

Fig. 9

zeigt die Seitenansicht der Schichten nach Fig. 8.

Fig. 10

zeigt die Draufsicht auf eine zweite Schicht des Plättchens der Formabrichtrolle nach Fig. 7.

Fig. 11:

zeigt die Seitenansicht eines aus den Schichten nach Fig. 8 und 10 zusammengesetzten Plättchens für die Formabrichtrolle nach Fig. 7.

The invention will be explained in more detail below with reference to drawings.

Fig. 1

shows the side view of a form dressing roll according to the invention in a schematic representation.

Fig. 2

shows an enlarged detail of the form dressing roll of FIG. 1st

Fig. 3

shows schematically a part of a radial section through the form dressing roller according to FIG. 1.

Fig. 4

shows the top view of a part of the form dressing roller according to FIG. 3.

Fig. 5

shows schematically a setting scheme for diamond grains of a layer of a form dressing roller according to FIGS. 1 to 4.

Fig. 6

shows the setting diagram of a form dressing roll with two layers according to FIG. 5.

Fig. 7

shows schematically another embodiment of a dressing roller according to the invention.

Fig. 8

shows a top view of a first layer of a plate of the dressing roller according to FIG. 7.

Fig. 9

shows the side view of the layers according to FIG. 8.

Fig. 10

shows the top view of a second layer of the plate of the form dressing roller according to FIG. 7.

Fig. 11:

shows the side view of a plate composed of the layers according to FIGS. 8 and 10 for the form dressing roll according to FIG. 7.

A form dressing roller for dressing diamond grinding wheels, not shown in ceramic, metallic or synthetic resin binding is shown at 10. The Form dressing roll has a carrier body 12, e.g. made of steel or the like, on which a covering 14 is applied. As can be seen in particular from FIG. 2, the covering consists of individual tufts of diamonds 16, which have approximately the same size, e.g. 0.9 mm or less. As can also be seen from Fig. 2, the Diamond grains 16 on rays 18 through a common center of the Form dressing roll 10 go. However, the diamond grains 16 are not all in one Level, but in two planes offset in the axial direction of the dressing roller 10. The Diamond grains 16 are in two with each other according to a predetermined setting scheme interlaced layers, the diamonds of one layer in Gaps of the adjacent layers are arranged. This is a little clearer 3 and 4 emerge. A covering 14a is indicated in FIG. 3 with the sides 20 and 21 and the peripheral surface 22. In addition, first diamond grains 24, the are characterized by circular lines and second diamond grains 26 which are additionally hatched. The hatching is only intended to indicate that the diamond grains 24 and 26 are not in the same plane, which is shown in FIG Circumferential direction and in Fig. 4 is meant in the radial direction. Like from the 3 and 4, the diamonds 24, 26 each form in the radial direction a layer or a plane, the diamonds of one layer being opposite the Diamonds of the other layer are offset, but are interlaced. The corresponding setting scheme according to which the diamonds 24, 26 are arranged can be seen as an example in FIG. 5.

5, six geometrically identical spirals 30 are arranged one inside the other the largest diameter is offset by 30 °. The spirals 30 are each drawn at an angle of approximately 360 °. Starting with the largest diameter six diamond grains 32 are therefore arranged at a distance of 30 °. On the drawn rays, which are arranged at a distance of 15 ° therefore alternately radially three or two diamonds 32 can be seen. The diamonds 32 are integrated into a matrix, which consists of a suitable binder, for example a galvanic or a sintered bond with a high proportion of tungsten. The binder is designated 34 in FIGS. 3 and 4. Become two layers 5 set against each other with a certain angular rotation results a diagram according to FIG. 6. In FIG. 6, the diamond grains 32 are in turn open the 15 ° offset rays, the diamond grains 36, the are additionally marked with a dot, each centered radially between the Rays arranged. However, the diamond grains 36 belong to one in the axial direction offset level, the offset being less than the size of a diamond. On An example of the size of an offset is shown in FIGS. 3 and 4. The offset is e.g. such that the thickness of the total covering, e.g. 14a according to FIGS. 3 and 4 is approximately 1.5 times the diameter of the diamond grains 24, 26 and 32, 36, respectively. On The outermost diameter of the dressing roll is therefore twelve diamonds centered around the common center of the spirals 30, which is also the The fulcrum of the form roller is. As wear progresses, diamonds come second in use on the spiral and so on. Thus also at progressive wear an almost constant surface geometry of the Receive form dressing roll that generates itself over the course of its lifespan. This applies in particular to the edges 40, 42 of the covering (FIGS. 3 and 4). The Edge radii remain constant over the course of the wear cross-section. Stay with it the profile radii on the workpiece to be dressed are also constant. Because the dressing volume the form dressing roll is relatively large, the geometric wear is in Direction of delivery relatively small, so that even larger profile trains with large ones Profile accuracy can be trained.

It is also possible, e.g. 5 on a single spiral 30 to be arranged in order to achieve uniform wear in the radial direction. at The diamond grains can have several spirals rotated relative to one another be arranged approximately in one plane to the minimum width of the covering from To obtain the diameter of a grain. During the manufacturing process, the diamond grains arranged on a meltable surface and with sinter powder covered and sintered to exclude a ring-shaped coating.

In Fig. 7, a form dressing roll 50 is shown schematically, which consists of a carrier body 52 and individual platelets 54 arranged radially on the carrier body 52 consists. In the present case, eight such platelets 54 are provided. The tiles 54 are in a matrix 56 made of a suitable, easily wearable binder 56 involved, e.g. has sintered cobalt. The structure of the tiles 54 emerges from FIGS. 8 to 11.

On a film 58 in FIG. 8 there are columns and rows of diamond grains 60 arranged. 10 are also columns and rows of Diamond grains 62 arranged. Between adjacent diamond grains 60 and 62, respectively there are sufficient gaps. Now the arrangement according to FIG. 8 Folded from above onto the arrangement according to FIG. 10, there is an arrangement such as it can be seen in part from FIG. 11. Between adjacent diamond grains 64 or in the gaps in the columns and rows of diamond grains 64, respectively Diamond grains 60 arranged, the diamond grains 60, 61 not in one plane lie, but are only partially entangled, as can be seen from Fig. 11. It This results in a relatively similar arrangement to that shown in FIGS. 3 and 4 is indicated. The diamond grains 60 and 64 are bound galvanically Base or by a sintered metal.

Claims (15)

Form dressing roll with a coating of diamond grains in a suitable bond for dressing diamond grinding wheels in a ceramic, metallic or synthetic resin bond, characterized in that the coating (14, 14a) consists of at least one layer, and individual diamond grains in a narrowly classified size in a vertical plane to the axis of rotation of the form dressing roller (10, 50) are arranged according to a predetermined setting scheme so that the surface geometry of the dressing roller (10, 50) remains approximately constant as the wear progresses. Form dressing roll according to claim 1, characterized in that the covering (14, 14a) consists of at least two layers, wherein in each layer individual diamond grains of narrow size are arranged in a plane perpendicular to the axis of rotation of the form dressing roll (10, 50) according to a predetermined setting scheme , wherein the diamond grains of one layer lie in gaps between the diamond grains of the other layer and partially protrude into the other layer such that the surface geometry of the dressing roller (10, 50) remains approximately constant as the wear progresses. Form dressing roll according to claim 2, characterized in that a covering of two layers has a width of approximately 1.5 times the grain size. Form dressing roll according to one of claims 1 to 3, characterized in that the size of the diamond grains is selected such that natural radii are produced on the edges of the covering, irrespective of the progress of wear, which correspond to a predetermined smallest concave radius of a grinding wheel. Form dressing roll according to one of claims 1 to 4, characterized in that the setting scheme has at least one spiral on which the diamonds are set, the center of the spiral being on the axis of rotation of the form dressing roll. Form dressing roll according to one of claims 1 to 5, characterized in that the setting scheme has a plurality of geometrically identical spirals (30) with a common center, the size of which are spaced apart by an equal angular distance in the circumferential direction and along which diamond grains (32) are set, the The center point lies on the axis of rotation of the form dressing roll. Form dressing roll according to one of Claims 2 to 4, characterized in that it consists of individual, preferably rectangular or trapezoidal, platelets (54) which are arranged one behind the other in the circumferential direction, each platelet having at least two layers, individual diamond grains of closely classified size in each layer a plane perpendicular to the axis of rotation of the dressing roller is arranged according to a predetermined setting scheme, the diamond grains (60) of one layer being in gaps in the diamond grains (64) of the other layer and partially protruding into the other layer such that the peripheral geometry of the dressing roller progresses in wear remains approximately constant. Form dressing roll according to claim 7, characterized in that the platelets (54) are held in a metallic matrix (56) made of easily sandable material. Form dressing roll according to claim 8, characterized in that the material consists of sintered cobalt. Form dressing roll according to one of Claims 1 to 9, characterized in that a galvanic or a sinter bond with a high proportion of tungsten is provided for the diamond grains. Form dressing roll according to one of claims 1 to 10, characterized in that the grain size is equal to or smaller than 0.3 mm. Form dressing roll according to one of claims 1 to 11, characterized in that the length of the abrasive coating in the infeed direction is 5 to 10 mm. A method for producing a form dressing roll according to claim 1, characterized by the following steps: Placing the diamond grains according to the specified setting scheme on an annular, meltable base, preferably with an adhesive layer, Adding binding powder, Cold compressing the material, sintering, Circumferential grinding of the annular covering thus produced. A method according to claim 13, characterized in that the diamond grains are placed along at least one spiral. Method for producing a form dressing roll according to claim 2, characterized by the following steps: Placing the diamond grains according to the specified setting scheme on a base with an adhesive layer to produce a layer, Adding binding powder, Stacking the desired number of layers with relative or angular displacement of the layers to form a package, Cold compressing the layer package, Sintering.

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