EP1928633B1 - Base for a rotating grinding or cutting tool, and grinding or cutting tool produced therefrom - Google Patents

Abstract

In a rotating grinding- or cutting tool, in particular a grinding wheel or grinding roller, on one body, a coating of abrasive material, e.g. cubic boron nitride (CBN) or diamond is applied. The body (2, 12, 22, 32, 42) has two side walls (2a, 12a, 22a, 32a, 42a; 2a, 12a, 22a, 32a, 42a) which are connected to each other on their peripheral region, with the side walls being constructed with fiber-reinforced composite, in particular carbon fiber-, glass fiber- or synthetic fiber-reinforced composite.

Description

The invention relates to a carrier body for a rotating grinding or cutting tool, in particular a grinding wheel, grinding cup or grinding drum, wherein on the carrier body a coating of an abrasive material, e.g. Cubic boron nitride (CBN) or diamond, can be applied.

The invention further relates to a rotary grinding or cutting tool, in particular a grinding wheel, grinding cup or grinding drum, the tool comprising a carrier body and at least one coating applied on a peripheral surface and / or at least one side surface of the carrier body of an abrasive material, e.g. Cubic boron nitride (CBN) or diamond.

Finally, the invention also relates to a method for operating a rotating grinding or cutting tool according to the invention.

High-speed grinding wheels currently in use comprise a carrier body of metal, in particular steel, aluminum or aluminum sintered alloys, on which a coating of abrasive material is applied, wherein the abrasive material coating can be applied to a peripheral surface of the carrier body and / or on the side surfaces of the carrier body ,

A disadvantage of these known grinding wheels on the one hand their high weight, which brings a considerable load on the spindle of a grinding machine on which the grinding wheel is mounted, as well as the bearing of the spindle with it. This weight load of the spindle and its bearings reduces the life of spindle and spindle bearings and thus leads to increased maintenance and repair costs and downtime of the grinding machine. The high weight of the known grinding wheels (typically in the range up to 100 kg) makes a manual change of the grinding wheels difficult or impossible. It must rather be used for almost every change a lifting means, which extends the change process to several hours or requires a complex automatic change and thus reduces the productivity of the grinding machine. Also in pendulum lifting, the high moving masses of the known make Grinding wheels particularly disturbing noticeable. The high weight also leads to increased energy consumption when driving the grinding wheel.

Another disadvantage of these known grinding wheels is their dynamic behavior. Thus, a reversal of direction due to the high moving mass is possible only very slowly. Since the natural frequency of the support body made of metal is usually in the order of the speed of the grinding wheel, must be expected with the occurrence of natural oscillations. Due to the high moving mass in the known grinding wheels and a tendency to unbalance is observed, which increases in proportion to mass x distance. Finally, with the known grinding wheels only a limited grinding speed can be achieved (which in practice is indicated in m / s peripheral speed). This is due to both the radial expansion of the support body at higher speeds and the relatively high thermal expansion coefficient of steel and aluminum, which leads to higher dimensional inaccuracy when heated during grinding and segmentation of the abrasive material coating required for larger slices.

Also known are fiber composite body made of pre-impregnated prepreg fabrics or layers, but due to their quasi-isotropic nature, only insufficient strength values, especially for grinding applications with a lateral axial load, have.

The present invention is therefore based on the object to provide a carrier body for a rotating grinding or cutting tool and a grinding or cutting tool produced therefrom, in which the disadvantages of the prior art are avoided.

The document GB 2 028 860 shows abrasive wheels with abrasive grains embedded in an Kunsthar-Z based binder and having high strength fiber reinforcement fill material. These grinding wheels are designed as full-abrasive bodies in which abrasive grains and a fiber reinforcement are embedded in a resin-based binder. Although this document addresses the problem of lack of lateral stability of the grinding wheels, the only solution is to improve the modulus of elasticity of the fiber reinforcement.

The document EP 0 501 022 A2 describes a grinding or cutting tool and a method for its production. This tool has a fiber-reinforced body with a plastic matrix on top and an abrasive coating of abrasive grains held in a bond. In order to strengthen the connection between the base body and the abrasive coating, a metal layer is applied to the base body, in which are embedded outwardly over the plastic protruding and anchored in the plastic electrically conductive fibers. The electrically conductive fiber sections are etched by etching. the plastic matrix of the body exposed and then applied the metal layer and then the abrasive coating. This document is considered to be the closest prior art. The grinding wheels disclosed therein do not have a separate carrier body with a coating of abrasive material disposed thereon, but are formed as a solid abrasive body.

The document CH 653 590 A5 describes an active damping and Auslenkregelungssystem for Innenschleifaggregate, wherein the grinding wheel-bearing mandrel is provided with a lying in the axis of rotation bore, in which a sensor element which detects vibrations and deflections of the dome, is arranged. The signals of the sensor control via a control and amplifier active damping elements in the form of piezo elements. These piezo elements are arranged between an inner sleeve and an outer sleeve, wherein the inner sleeve carries a roller bearing pair, which carries the grinding spindle with the mandrel. It is therefore an extremely complicated mechanical construction which by no means suggests placing piezo elements in the grinding wheel. In addition, the purpose of the known device is different, namely to dampen vibrations on the grinding spindle, but not on the grinding wheel.

The document EP 0 523 260 A1 discloses a master blade for circular saw blades and / or cut-off wheels, consisting of a circular, at least partially consisting of einm with fiber reinforced plastic material disc body. The fibers are, based on the circular shape of the disk body, embedded in a radial orientation and in a uniform distribution over the circumference of the disk body in the plastic material.

The document DE 195 38 841 A1 relates to a grinding wheel having a cylindrical abrasive surface for working non-metallic surfaces. This abrasive article has a profiled abrasive surface.

The object of the invention is achieved by a carrier body for a rotating grinding or cutting tool with the features of claim 1 and by a grinding or

Cutting tool with the features of claim 25 solved. Advantageous embodiments of the invention are set forth in the subclaims.

The rotationally symmetrical carrier body according to the invention for a rotating grinding or cutting tool, in particular a grinding wheel, grinding cup or grinding drum, comprises two side walls, which are interconnected at their peripheral area, wherein the side walls comprise a fiber-reinforced composite material, in particular a carbon fiber, glass fiber, aramid fiber material. , Basalt fiber or synthetic fiber reinforced composite, exhibit. Fiber-reinforced composites are also referred to in the literature as fiber composites. Advantageously, the fiber composites are injected during the manufacturing process or thereafter with a synthetic resin, which is subsequently cured, whereby the carrier body can be realized in substantially free forms. To increase the structural strength, microfibers or nanofibers made of a reinforcing material such as carbon fibers, glass fibers, aramid fibers, basalt fibers, or synthetic fibers may be embedded in the synthetic resin.

The carrier body is made according to the invention in a lightweight construction, which allows a reduction of its weight to up to 1/10 of the weight of conventional metal carrier body. Nevertheless, the carrier body according to the invention due to the use of fiber-reinforced composite material has an extremely high strength and rigidity, which is even more dramatically increased in the embodiment with two spaced apart side walls in relation to the absorption of lateral forces. The drastically reduced weight of the carrier body according to the invention leads to a lower spindle load of the grinding machine and thus increases the life of the grinding spindle and thus reduces the maintenance and repair costs and downtime of the production plant. Grinding tools made using the support body of the present invention have such low weight that they can be mounted on the grinding machine without any lifting means, reducing the time required for a tool change to a fraction of that of known grinding wheels (up to 1 hour instead of 5 hours). As a result of the greatly reduced weight of the carrier body according to the invention, considerable reductions in the electrical power consumed by the machine can also be achieved.

Another great advantage of the carrier body according to the invention or of rotating grinding and cutting tools produced using this carrier body is the vibration-damping behavior of the composite material or the good adjustability of the natural frequency of the tool to values significantly above the rotational speed of the tool, preferably more than twice or three times over it, so that natural oscillations remain low. The adjustability with respect to damping and vibration behavior is calculated or can be determined iteratively. Due to the reduced weight and the occurrence of imbalance is greatly reduced. Furthermore, a higher machine dynamics can be achieved, ie reversing the direction of rotation is much faster. The grinding wheel according to the invention is also particularly well suited for reciprocating grinding or non-circular grinding.

Abrasive coatings for high-speed grinding consist of the CBN / diamond grain, bond and pores, whereby, for example, ceramic and resin-bonded CBN / diamond coatings are bonded to the base body mainly by adhesion. In the case of galvanically bonded CBN grinding wheels, which are mainly used for profiled grinding surfaces and gear grinding, a thin, metallic, optionally profiled ring is additionally applied to the carbon or CFRP body at the outer circumference so that the electroplating process is physically possible.

In general, higher speeds of the tool with the carrier body according to the invention can be achieved without excessive material stress, since the carrier body of fiber composites of the invention compared with metallic support bodies has a very low material expansion at high speeds and provides a much better dimensional accuracy than the known carrier body made of metal or CFRP prepregs , Due to the higher speed or the higher peripheral speed of the tool, a higher workpiece speed in conjunction with higher feed values is possible. This achieves higher metal removal rates and increased productivity. The achievable speed are mainly limits set by possibly occurring grinding burn.

The compared to the known support bodies reduced coefficient of thermal expansion of the composite body according to the invention leads to a higher dimensional accuracy over a wide temperature range and makes, inter alia, thereby the segmentation of Schleifkömer coating superfluous even for larger discs. The continuous coating of the carrier body with abrasive material leads to optimized surface quality, improves the grinding breakout behavior and thus increases the service life of the grinding wheel.

The fields of application of the invention are very extensive. They range from the formation of the carrier body according to the invention as a grinding wheel carrier body to the outer and inner cylindrical grinding of components. Further fields of application of the invention relate to surface grinding, grooving, profile grinding and tool grinding. In particular, the invention can be used advantageously in the fields of wave grinding, in particular crankshaft grinding, gear shaft grinding, compressor wheel grinding, camshaft grinding, roll grinding, peel grinding, gear grinding (for which profiled disks are used, the high lateral Must take loads, for which the present invention is best) and centerless grinding using a grinding wheel type in drum shape, ie a grinding drum, for example, be used with a diameter of over 1000mm and a length ranging from about half a diameter to a multiple of the diameter. Such grinding drums can be optimally produced with the invention. Furthermore, combined with the invention components of flange and shaft extension with bearings and disc-shaped components can be produced. Likewise, the invention relates to grinding wheels and grinding heads for the wafer grinding of the semiconductor industry.

To support bodies having a circumferential surface of large axial length, e.g. To realize a carrier body in drum shape, it is expedient if the side walls are not connected to each other at its peripheral portion not directly, but by a peripheral wall having the same composite material as the side walls or another fiber reinforced composite material.

A particularly light, highly stable and extensive degrees of freedom in shaping providing carrier body is obtained if between the side walls at least partially a core material, in particular a honeycomb core, preferably made of aramid, or a foam core, is arranged. Other suitable core materials include wood or minerals, e.g. Granite. Hollow chambers may also be suitable.

The carrier body according to the invention allows the formation of its side walls and possibly the peripheral wall as curved surfaces or free-form surfaces. This makes it possible to produce rotating grinding tools based on the carrier body according to the invention, which are used for demanding tasks such as peeling grinding and face shoulder grinding.

For easier attachment of the carrier body or a grinding wheel made therefrom to the receiving of a machine spindle, it is expedient if the carrier body has a hub which passes through the side walls centrally. The hub may optionally be formed as a metal element.

For the realization of an internal cooling or lubrication of the carrier body is provided in one embodiment of the invention that in the support body cooling and lubricant connections and outlets are formed, preferably at least one coolant and lubricant connection in a central region of a side wall, in particular in the area of the hub, is formed and leads into the space between the side walls and at least one coolant and lubricant outlet is formed through a sidewall or through the outer peripheral wall and perforated or porous abrasive segments. The supply of the carrier body with coolant and lubricant takes place via the machine spindle, in which corresponding, corresponding channels are formed, or via lateral accesses.

To increase the resistance of the carrier body according to the invention to compressive stresses and to avoid material damage of the side walls of the carrier body by crushing, especially when clamping in a machine, is provided in a variant of the invention that are provided by both side walls passing spacer sleeves, the spacer sleeves preferably are fixed by means of interference fit and adhesives in the side walls. The spacer sleeves are in this case e.g. mounted in one or more concentric circles in the force introduction region of the carrier body. Preferably, the spacer sleeves are conically shaped, so that positive engagement exists and they can not dissolve from Trägersträger.le. Furthermore, it has proved to be advantageous to fine balance the carrier body by steel pins are used with different lengths and diameters, for which holes are drilled in the preparatory operation with corresponding diameters in the carrier body. Even by the mere provision of holes balancing can be achieved. The holes and steel inserts can be arranged on arbitrary pitch circles.

In order to achieve the highest possible stability and rigidity of the carrier body according to the invention, various advantageous laying directions of the fibers of the composite are proposed according to the invention, which can be applied individually or in combination depending on the required shape of the carrier body. In a preferred embodiment, the fibers of the composite material are laid according to the force curve calculated for the use in the side walls or the peripheral wall. In this case, fibers can also be wound around deflection points, wherein pins can be used as deflection points. In particular, fibers of the composite in the sidewalls may be disposed substantially radially or arcuately extending from the center of the sidewall to the periphery to minimize material strain. For the same purpose, the fibers may be arranged specifically in the sidewalls and also in the peripheral wall in the tangential circumferential direction in concentric and eccentric circles, respectively. High stability is also achieved if in the sidewalls fibers of Verbundwelkstoffs circular, elliptical and / or spirally arranged extending from the center to the periphery. Especially with carrier bodies with a large axial length of the peripheral wall, it is advantageous in the peripheral wall fibers of the To arrange composite material helically in the axial direction. A drastic increase in the rigidity of the carrier body is achieved if the fibers are arranged in a plurality of layers in the side walls and optionally the peripheral wall, in particular in a cross position.

A further increase in the rigidity of the carrier body according to the invention and its ability to absorb lateral forces can be achieved if the side walls are connected to one another by transverse webs. The transverse webs may be in any shape, e.g. in the radial straight direction, radial arc shape or in the circumferential direction on different pitch circle diameters, be formed.

Excellent rigidity of the carrier body in its peripheral region is achieved if a band with unidirectional reinforcing fibers is arranged around the peripheral region.

A further reduction of the weight of the carrier body according to the invention while maintaining the necessary stability can be achieved if the thickness of the side walls tapers from a central region towards the circumference or vice versa at least in sections.

Further degrees of freedom in the design of the carrier body according to the invention are obtained by gluing individual parts of the carrier body together. For example, the diameter can thus be reinforced in a central region of the carrier body.

The invention also provides to combine the actual support body with flanges, shafts, spindles, etc., either by the aforementioned bonding or by a one-piece design to reduce the total weight of this group of components and thereby drive higher speeds with lower energy consumption and can to obtain an optimized and integrated vibration system.

In a particularly preferred embodiment of the invention, which enables the active damping of vibrations in the carrier body, the fiber-reinforced composite material of the side walls and optionally the peripheral wall with energy converter materials (so-called adaptive materials), such as piezoelectric, in particular piezoceramic films and fibers, or magnetostrictive or electroactive materials, combined. The energy converter materials are partially connected as sensors with an electrical control to detect mechanical vibrations as they occur, and deriving therefrom a control signal, which in turn different Energiewandler materials that are operated as actuators, is supplied to counteract the mechanical vibrations. Piezo fibers and foils without energy supply can also be used, but they have a lower damping effect. Furthermore, the piezo fibers and foils can be connected to energy stores or externally supplied with energy via the spindle in order to achieve a higher damping effect.

Finally, in one embodiment of the invention, provision is also made for a data carrier, preferably a contactless recordable and readable data carrier, to be introduced into one of the walls of the carrier body in order to store production data, etc.

The invention also encompasses a rotating grinding or cutting tool, in particular a grinding wheel or grinding drum, which comprises a carrier body according to the invention and at least one covering made of an abrasive material, for example applied to a peripheral surface and / or at least one side surface of the carrier body. Cubic boron nitride (CBN) or diamond. In one embodiment, the carrier body is connected by means of positive connection, in particular a dovetail connection, with the lining of abrasive material. Also, because of this solid compound, it is possible in contrast to the prior art, the lining of abrasive material in one piece in ring form instead of segmented form. Alternatively or in addition to the positive connection, the carrier body can be connected by means of adhesive bonding to the covering made of abrasive material.

• das Einlegen von zumindest einem Schleifbelagselement in die Werkzeugform,
• das Einlegen von Verstärkungsfasern (Preformen), insbesondere Kohlefasern, Glasfasern, Aramidfasern, Basaltfasern oder Synthetikfasern in eine Werkzeugform,
• das integrierte Tränken bzw. Injizieren mit Kunstharz und Aushärten der Verstärkungsfasern sowie der Verbindungsstellen zwischen den Verstärkungsfasern und den Schleifbelagselementen.

According to the state of the art, CBN / diamond abrasive coatings are bonded to the carrier body by means of adhesive. A substantial increase in the adhesive force between abrasive coating and carrier body is achieved according to the invention by an integrated impregnation or injection with synthetic resin and curing of the carbon fiber preforms, etc., as well as the joint of abrasive coating and the underlying carrier body. In a process step, the impregnation of the preforms of the carrier body and the splice occurs. The subsequent curing also takes place together. In summary, the manufacturing process has the following steps:

• the insertion of at least one abrasive covering element into the mold,
• the insertion of reinforcing fibers (preforms), in particular carbon fibers, glass fibers, aramid fibers, basalt fibers or synthetic fibers into a mold,
• the integrated impregnation or injection with synthetic resin and curing of the reinforcing fibers and the joints between the reinforcing fibers and the abrasive covering elements.

Finally, the invention also encompasses a method for operating a rotating grinding or cutting tool according to the invention, which is characterized in that the grinding or cutting tool is pivoted in the direction of the force resulting from the vector addition of contact force and feed force. This increases the stability of the grinding wheel carrier body and the service life of the abrasive coating by optimally compensating the anisotropy of the strength of the materials used.

• Fig. 1 zeigt eine erfindungsgemäße Schleifscheibe im Längsschnitt.
• Fig. 2 zeigt einen erfindungsgemäßen Trägerkörper im Längsschnitt.
• Fig. 3 zeigt ein Detail einer weiteren Ausführungsform eines erfindungsgemäßen Trägerkörpers.
• Fig. 4 zeigt im Teillängsschnitt und in Teilansicht einen trommelförmigen Trägerkörper gemäß der Erfindung.
• Fig. 5 stellt einen Längsschnitt einer weiteren Ausführungsform einer erfindungsgemäßen Schleifscheibe 41 dar.
• Fig. 6 zeigt in Seitenansicht eine Seitenwand eines erfindungsgemäßen Trägerkörpers.
• Fig. 7 zeigt in Seitenansicht eine Seitenwand eines weiteren erfindungsgemäßen Trägerkörpers.
• Fig. 8 zeigt ein Beispiel für spitzenloses Schleifen unter Verwendung einer Schleiftrommel mit einem erfindungsgemäßen Trägerkörper.
• Fig. 9 zeigt ein weiteres Beispiel für spitzenloses Schleifen unter Verwendung einer Schleiftrommel mit einem erfindungsgemäßen Trägerkörper.
• Die Figuren 10A und 10B zeigen in einer Schnittansicht bzw. in Draufsicht eine weitere Ausführungsform eines Trägerkörpers
• Die Figuren 11A und 11B zeigen in einer Schnittansicht bzw. in Draufsicht eine weitere Ausführungsform eines erfindungsgemäßen Trägerkörpers
• Die Figuren 12A und 12B zeigen in einer Schnittansicht bzw. in Draufsicht eine weitere Ausführungsform eines erfindungsgemäßen Trägerkörpers.
• Die Figuren 13A und 13B zeigen in einer Schnittansicht bzw. in Draufsicht eine weitere Ausführungsform eines erfindungsgemäßen Trägerkörpers.
• Die Figuren 14, 15, 16 zeigen in Querschnittsansichten Ausführungsformen von erfindungsgemäßen Schleif- bzw. Schneidwerkzeugen, die eine formschlüssige Verbindung zwischen dem Trägerkörper aus faserverstärktem Verbundwerkstoff und einem Belag aus Abrasivmaterial aufweisen.
• Fig. 17 erläutert ein Verfahren zum Betrieb eines rotierenden Schleif- bzw. Schneidwerkzeugs.
• Fig. 18 zeigt im Längsschnitt eine weitere Ausführungsform eines trommelförmigen Trägerkörpers gemäß der Erfindung.

The invention will now be described by way of non-limiting example with reference to the drawings.

• Fig. 1 shows a grinding wheel according to the invention in longitudinal section.
• Fig. 2 shows a carrier body according to the invention in longitudinal section.
• Fig. 3 shows a detail of another embodiment of a carrier body according to the invention.
• Fig. 4 shows in partial longitudinal section and in partial view a drum-shaped carrier body according to the invention.
• Fig. 5 FIG. 3 shows a longitudinal section of a further embodiment of a grinding wheel 41 according to the invention. FIG.
• Fig. 6 shows in side view a side wall of a carrier body according to the invention.
• Fig. 7 shows in side view a side wall of another carrier body according to the invention.
• Fig. 8 shows an example of centerless grinding using a grinding drum with a carrier body according to the invention.
• Fig. 9 shows another example of centerless grinding using a grinding drum with a carrier body according to the invention.
• The Figures 10A and 10B show in a sectional view or in plan view a further embodiment of a carrier body
• The Figures 11A and 11B show in a sectional view or in plan view a further embodiment of a carrier body according to the invention
• The Figures 12A and 12B show in a sectional view or in plan view a further embodiment of a carrier body according to the invention.
• The FIGS. 13A and 13B show in a sectional view or in plan view a further embodiment of a carrier body according to the invention.
• The FIGS. 14, 15, 16 show in cross-sectional views embodiments of grinding or cutting tools according to the invention, which have a positive connection between the carrier body made of fiber-reinforced composite material and a lining of abrasive material.
• Fig. 17 illustrates a method for operating a rotating grinding or cutting tool.
• Fig. 18 shows in longitudinal section a further embodiment of a drum-shaped carrier body according to the invention.

Fig. 1 shows in longitudinal section a first embodiment of a grinding wheel 1 according to the invention. The grinding wheel 1 comprises a rotationally symmetrical support body 2, on the circumference of which an abrasive material 3, for example cubic boron nitride (CBN), is applied. The carrier body 2 has two spaced-apart side walls 2a, 2b, which are interconnected at their peripheral region via a peripheral wall 2c. The carrier body 2 is designed rotationally symmetrical and has in its center on a hub 4 which is rotatable about a rotation axis A. According to the invention, the side walls 2a, 2b and the peripheral wall are made of a fiber-reinforced composite material, wherein carbon fiber, glass fiber or synthetic fiber reinforced composite materials are preferred. Carbon fiber reinforced plastics (CFRP), glass fiber reinforced plastics (GRP) or synthetic fiber reinforced plastics (SFK) are particularly well suited. Aramid or basalt fibers can also be used as reinforcing fibers. In the course of the manufacturing process of the carrier body 2, the reinforcing fibers can be embedded in a matrix of synthetic resin, in particular epoxy resin, wherein the synthetic resin can also contain microfibers or nanofibers for increasing the strength, eg carbon fibers, glass fibers, aramid fibers, basalt fibers or synthetic fibers. The side walls 2a, 2b, the peripheral wall 2c and the hub 4 enclose a cavity 6. Due to the mutual spacing of the side walls 2a, 2b, the carrier body 2 is outstandingly suitable for receiving lateral forces. Its special feature is the low weight combined with excellent strength and rigidity due to the use of fiber reinforced composite material. To further increase the rigidity of the carrier body 2, the side walls 2a, 2b are connected to each other at approximately half the radius of the carrier body by a circumferential cylindrical web 5. It should be noted, however, that instead of a cylindrical web 5, a plurality of individual webs may be provided, which are configured, for example, rod-shaped or circular-segment-shaped. In order to prevent the side walls 2a, 2b from being damaged by transverse forces or pinching, a plurality of spacer sleeves 9 arranged in a circle around the hub 4 are press-fit through the side walls 2a, 2b in the carrier body 2 fixed. Alternatively, the carrier body may also be at least partially formed as a solid body, with foam cores can be used to save weight, see Figure 12 ,

Furthermore, in the hub 4, a coolant and lubricant connection 7 is formed, guided by the coolant and lubricant from a machine spindle, not shown, into the cavity 6 of the carrier body 2 and through a coolant and lubricant outlet 8, which passes through the side wall 2a is formed, can be discharged from the cavity 6 of the carrier body 2. So that the coolant and lubricant can pass from the hub region into the peripheral region of the cavity 6, the cylindrical web 5 has at least one through-hole 5a. The outlet for the coolant and lubricant may also be through the peripheral wall and perforated or porous abrasive segments. In principle, the carrier body can also be realized without a hub, which should also be the goal, in particular for less demanding applications, for cost reasons.

For reasons of weight saving, the wall thickness of the side walls 2 a, 2 b decreases from the hub region to the peripheral region, with a constant wall thickness d 1 being initially provided from the hub 4 to approximately the web 5, which then reduces to a smaller wall thickness d 2 relative to the peripheral region. The dimensioning of the wall thicknesses d1, d2 takes place as a function of the expected load on the carrier body. The balancing quality of the carrier body according to the invention can be adjusted on the one hand via the selected manufacturing process and on the other hand via mechanical post-processing. The same applies to dimensional, shape and bearing tolerances, in particular for the roundness, the concentricity and the flatness as well as the parallelism at the force introduction point. It is also possible to form the carrier body 2 without a separate hub, that is to provide a solid body section at least in the center region, which can be connected directly to a machine spindle, spacer sleeves and spacer pins also being able to be inserted into this solid body section. Furthermore, it has proved to be advantageous to fine balance the carrier body 2 by steel pins are used with different lengths and diameters in the solid body portion, for which holes are drilled with corresponding diameters in a preparatory operation.

Fig. 2 shows a further carrier body 12 according to the invention in longitudinal section. This carrier body 12 comprises two side walls 12a, 12b, which approach each other towards the circumference 12c. The side walls 12a, 12b are directly connected to each other, ie without a peripheral wall therebetween. Reference numeral 12e denotes a connecting joint. Furthermore, the side walls are at their peripheral area of one unidirectional band 12d - preferably of CFK - surrounded having extending in a direction reinforcing fibers. Suitably, the unidirectional belt 12d is first inserted into a mold during production and then the side walls 12a. 12b inserted as preforms in the mold, whereupon a resin impregnation step and a curing step are performed. As the side walls 12a, 12b approach each other towards the periphery, they define between each other a cavity 6 which is partially filled by a foam 13.

For actively damping vibrations in the support body 12 and changing its stiffness, energy converters materials 14, 15, also referred to in the art as adaptive materials, are loaded in the fiber reinforced composite of the sidewalls 12a, 12b. These energy converter materials convert mechanical forces into electrical or magnetic forces or vice versa. Such energy converter materials include, for example, piezoelectrics, in particular piezoceramic films and fibers, or magnetostrictive or electroactive materials. In the present embodiment, the energy converter materials are formed as piezoceramic films 14, 15 which are inserted during the preform production for the side walls 12a, 12b between layers of the fiber-reinforced composite material. In this case, some of the piezoceramic foils 14 are used as sensors which convert mechanical forces acting on them into electrical signals due to vibrations, and others of the piezoceramic foils 15 are used as actuators which compensate the detected vibrations by movements (displacement, displacement, expansion, contraction , Deflection) counteract actorically, their movements being controlled by an electronic controller 17, which receives the sensor signals of the piezoceramic films 14 on the one hand and calculates corresponding control signals therefrom, and on the other hand activates the piezoceramic films 15 with these control signals. The regulator 17 is connected to the piezoceramic foils by means of electrical conductors 16. It is also possible, instead of the proposed active, electronically controlled damping to realize a simpler, semi-passive damping, in which instead of an electronic regulator, a simple electrical wiring of the lines 16 takes place, which can be integrated directly into the carrier body 12. For example, the electrical pulses supplied by the piezoceramic foils 14 can be supplied to the piezoceramic foils 15 either directly or via intermediate storage in an electrical storage element. An even simpler, albeit inferior in efficiency damping is obtained when piezo fibers and / or piezo elements are used without energy supply. The energy converter materials can also be attached to the outside or inside of the walls of the carrier body.

The production of this support body 12 is advantageously carried out by building the side walls 12a, 12b as two component halves to form the side walls of preforms of the fiber reinforced composite material, placing the foam 13 on the side wall 12a, placing the second side wall 12b on the foam 13, so the two side walls abut against each other at the joint 12d, the application of circumferential fibers in the peripheral portion 12c, the introduction of the entire structure into a curing mold (not shown), the injection of the side walls 12a, 12b and their bonded peripheral portion 12c with a synthetic resin and the Curing the synthetic resin and removing the carrier body from the Aushärteform. Subsequently, the hub 4 can be pressed.

Fig. 3 shows a detail of another embodiment of a support body 22 according to the invention, wherein the side walls 22a, 22b are arranged on the peripheral portion 22c so as to overlap each other over the entire peripheral portion 22c, whereby an excellent rigidity in the peripheral portion 22c is achieved. It should be noted that the overlap can also go so far that the side walls completely overlap each other, ie, so that there is a two-walled configuration. To further increase the strength of the carrier body, three bands 22d, 22e, 22f with unidirectional reinforcing fibers are disposed around the peripheral portion 22c, with the band 22d outwardly around the side walls 22a, 22b, the band 22e between the side walls, and the band 22f inside on the side walls 22a, 22b is fixed.

Fig. 4 shows in partial longitudinal section and in partial view a drum-shaped carrier body 32 with side walls 32a, 32b, which are interconnected at great axial distance by a peripheral wall 32c, wherein the side walls 32a, 32b and the peripheral wall 32c are constructed on a foam core 36. The fiber-reinforced composite material is arranged in the circumferential wall 32c in cross-layers such that the fibers 34, 35 extend helically in the axial direction of the peripheral wall, wherein for the production of a winding technique is used, in which the fibers run through an impregnating bath before winding, then are wound in the desired configuration in the wet state and then the thus formed body is cured. The drum-shaped carrier body 32 thus has a design with CFK fiber present on all sides and an inner filler body (core). The present embodiment of the carrier body 32 is ideal for the production of a grinding drum for the centerless grinding of products after the Durchführ- or puncture method, wherein for the puncture method, the peripheral wall 32c may also be constructed more complicated (eg different cylindrical sections with different diameters) to allow the grinding of products with other than cylindrical shape.

A further embodiment of a drum-shaped carrier body 161 is shown in longitudinal section in FIG Fig. 18 shown. The carrier body 161 is designed as a hubless carrier body, ie it has a central cylindrical cavity 165 which is plugged in operation on a spindle. The support body 161 has a structure 162 of fiber reinforced plastic, the structure 162 having an inner wall 162d defining the cavity 165, side walls 162a, 162b, and an outer peripheral wall 162c. These walls enclose a foam core 166. The production of this support body 161 takes place by first winding the inner wall 162d on a mandrel (not shown). Subsequently, the foam core 166 is applied and subsequently the side walls 162a, 162b and the peripheral wall 162c are wound. During production, the fibers pass through an impregnating bath prior to winding, are then wound up in the wet state in the desired configuration, and then the shaped body is cured. The drum-shaped carrier body 161 thus has a design with CFK fiber present on all sides and an internal filling body 166.

Fig. 5 FIG. 3 shows a longitudinal section of a further embodiment of a grinding wheel 41 according to the invention, which shows that the carrier body 42 can also be largely constructed in free form. It is a foam core 46 is used, on which the side walls 42a, 42b are constructed, which are joined together at the periphery 42c. The grinding wheel 41 is provided for side grinding, for which reason an annular coating 43 of abrasive material is applied to the side wall 42a.

Using foam cores and honeycomb cores, a wide variety of embodiments of the support body can be realized, e.g. Shell shapes, discs with recesses, cup wheels, in particular cup wheels specially for wafer grinding, beveled shells, shapes with tapers, etc. It should be further noted that the two side walls need not be spaced apart over the entire carrier body, but at least partially merge into each other can, ie can form a full wall.

As a rule, the carrier bodies according to the invention are produced in multiple layers from one or more fiber-reinforced composite materials. To achieve high dimensional accuracy, rigidity, stability and to prevent circumferential expansion Depending on the purpose of different laying arrangements of the fibers of the fiber-reinforced composite expediently. The following is a discussion of some basic types of lice that can be used individually or in combination.

Fig. 6 shows in side view a side wall 52a, in which a half arcuate course of fibers 54, 55 is illustrated from the center of the side wall to its circumference, wherein the fibers 54, 55 are in a cross position, and in the other half of the side wall 52a a radial Course of fibers 56 is shown. Furthermore, fibers 57 are provided with a tangential course in the form of concentric or eccentric circles.

Fig. 7 FIG. 11 shows in side view a side wall 62a in which the fiber 65 spirals from the hub to the circumference and is in a cross-plane with radial fibers 64. Instead of the spiral course and fibers in circles (tangential arrangement), ellipses and concentric and eccentric circles can be arranged in multiple layers.

In the FIGS. 8 and 9 Examples of centerless grinding using a grinding drum 71, 81 with a carrier body 72, 82 according to the invention are shown. The workpiece 76, 86 to be ground thereby rests on a support ruler 75. A counter drum 74, 84 presses the workpiece 76, 86 against the peripheral surface 72c, 82c of the grinding drum, the peripheral surface 72c (FIG. Fig. 8 ) has a cylindrical shape and the peripheral surface 82c ( Fig. 9 ) is designed several times discontinued.

Carbon fiber rovings (carbon rovings) or the like are used to produce the carrier body according to the invention. An insert may be provided, e.g. made of foam, on which the walls of the fiber-reinforced composite material are built. The compound of the carrier body with the abrasive material is expediently carried out by means of an adhesive, in particular an epoxy resin adhesive.

In the Figures 10A and 10B a further embodiment of a carrier body 92 is shown, wherein Fig. 10B a top view and Fig. 10A a sectional view along the line AA of Fig. 10B represent. This carrier body 92 is suitable for grinding concave camshafts and is designed as a solid body in a pure winding technique. For the production of carbon fibers (carbon rovings) or the like are wound around a rotating mandrel and thereby withdrawn from a spool. The winding process is a wet process, which means that the carbon rovings are pulled through an impregnating bath just prior to positioning on the winding mandrel and cured after completion of the winding process in an oven. The final geometry is created by mechanical CNC machining. The main advantage of the carrier body 92 is its low mass and thus the optimized unbalance, damping and thus vibration behavior. The abrasive coating is applied to collars 93, 95 on the outside diameter. The attachment to the spindle by means of a screw through the inner bore 94. If necessary, a highly accurate fit inside a steel insert is introduced.

In the Figures 11A and 11B a further embodiment of a carrier body 102 according to the invention is shown, wherein Fig. 11B a top view and Fig. 11A a sectional view along the line AA of Fig. 11B represent. This carrier body 102 is provided for the grinding of shafts with flat shoulders or the flat grinding. Face shoulder grinding refers to shaft shoulders where the surface is to be machined 90 ° to the longitudinal axis. The carrier body 102 is constructed in sections as a solid body made of fiber-reinforced composite material and offers a CFRP-compliant, completely novel geometry with curved surfaces 103, 106 on both sides, on which a coating of abrasive material is applied. Instead of the curved surfaces 103, 106, free-form surfaces can also be formed. The carrier body 102 is fastened by means of the threaded holes 104 directly or via the larger inner bore on a grinding machine and further has small through holes 105, can be used in the not shown for fine balancing steel pins of different lengths. The production takes place by a solid fiber construction on a foam core 107.

The Figures 12A and 12B show a further embodiment of a carrier body 112 according to the invention, wherein Fig. 12B a top view and Fig. 12A a sectional view along the line AA of Fig. 12B represent. The carrier body 112 is constructed of fiber-reinforced composite material, in which are arranged circularly arranged conical spacers 113, which have through-holes 114, so that the carrier body 112 can be screwed directly onto a rotating spindle of a grinding machine. At the periphery of the carrier body 112, a metallic ring 115 as a base for the galvanic attachment / coating of a coating of abrasive material, in particular CBN / diamond abrasive coating, arranged.

The FIGS. 13A and 13B again show a further embodiment of a carrier body 122 according to the invention, wherein Fig. 13B a top view and Fig. 13A a sectional view along the line AA of Fig. 13B represent. The carrier body 122 differs from the previous embodiments in that it consists of two Parts composed of fiber reinforced composite material, namely a cylindrical disc 123 and a conical reinforcing disc 124. The two discs 123, 124 are bonded together at their interface 125. It should be noted that, instead of the conical reinforcing disc 124, a fiber reinforced composite spindle sheath could be connected to the disc 123, thereby forming an assembly which is a unit of the actual cutting / grinding tool whose support body is the disc 123 and a spindle , which is connectable to the drive of a grinding machine. The reinforcing disk 124 can also be made in other material qualities such as steel or aluminum.

The invention also provides a rotating grinding or cutting tool in which a carrier body made of fiber-reinforced composite material is connected by means of positive connection with a coating of abrasive material. The positive connection is preferably a dovetail connection. The FIGS. 14, 15 and 16 show in each case in cross-section different embodiments of such grinding or cutting tools. Fig. 14 FIG. 5 shows a grinding wheel 131 having a fiber reinforced composite support body 132 and a coating 134 of abrasive material bonded to the support body 132 via a dovetail joint 133. In the dovetail region of the abrasive material there are transverse through holes 135, through which fibers are passed in the production of the grinding wheel 131, in order to achieve an even better bonding of carrier body 132 and abrasive material 134. Fig. 15 FIG. 12 shows a grinding wheel 141 having a fiber reinforced composite support body 142 and a coating 144 of abrasive material bonded to the support body 142 via a dovetail joint 143. This embodiment is different from that of Fig. 14 by an inverted dovetail connection, which is considered to be even more durable, since the coating of abrasive material 144 rests against the outer surfaces of the dovetail element of the support body 142 and compresses it upon the application of centrifugal forces. Fig. 16 shows a grinding wheel 151 with a carrier body 152 of fiber reinforced composite material and an outer ring of abrasive material 154, which is connected to the carrier body 152 via a simple dovetail connection (undercut). This grinding wheel 151 is particularly easy to produce.

It is further proposed to connect the carrier bodies 132, 142, 152 with the coverings of abrasive material 134, 144, 154 not only via the form-fitting dovetail connections, but additionally with each other be bonded, which in addition to thermosets as adhesives and thermoplastics can be used, which are toughened than thermosets.

• 1) Die Segmente aus Abrasivmaterial werden in die Werkzeugform aussen am Umfang noch vor dem Einlegen der Preformen und noch vor dem Injizieren des Trägerkörpers eingelegt bzw. angeordnet.
• 2) Es kann eine formschlüssige Schwalbenschwanzverbindung geschaffen werden, indem die Preformen (das sind die noch nicht injizierten Faserhälften) des Trägerkörpers derart gestaltet werden, dass eine Art Schwalbenschwanz-Nut oder - Feder am Außendurchmesser entsteht. Die Schwalbenschwanz-Gegenform ist dabei an der Belagsinnenseite angebracht.
• 2a) Optional werden die Segmente noch vor dem Injizieren mit einem geeigneten Epoxyharzkleber eingestrichen. Dieser warm aushärtende Epoxyharzkleber muss eine bestmögliche Bindung mit dem Epoxyharz, das beim Injizieren und Aushärten des Grundkörpers verwendet wird, eingehen bzw. kann auch das gleiche Epoxyharz verwendet werden.
• 3) Gemeinsames Injizieren, Tempern und Aushärten der Preformen sowie der Klebefläche mit den eingelegten Segmenten aus Abrasivmaterial.

According to the prior art, segments made of CBN and the carrier body have been manufactured separately and then connected together by an adhesive bond. However, the inventor proposes another, novel approach in which a further improved bonding of the CBN segments, ie the Abrasivmaterialbelags on the carrier body made of fiber-reinforced composite material is realized in a process step. This manufacturing method comprises the following steps:

• 1) The segments of abrasive material are inserted or arranged outside in the tool shape on the circumference before inserting the preforms and before injecting the carrier body.
• 2) A form-fitting dovetail connection can be created in that the preforms (that is, the fiber halves not yet injected) of the carrier body are designed in such a way that a type of dovetail groove or tongue is formed on the outside diameter. The dovetail counterform is attached to the lining inside.
• 2a) Optionally, the segments are coated with a suitable epoxy resin adhesive prior to injection. This thermosetting Epoxyharzkleber must be the best possible bond with the epoxy resin, which is used in the injection and curing of the base body, enter, or the same epoxy resin can be used.
• 3) Joint injection, annealing and curing of the preforms and the adhesive surface with the inserted segments of abrasive material.

The proposed manufacturing method of the grinding / cutting tools according to the invention also allows ring pads made of abrasive instead of the usual segments form to additionally generate a positive connection with the carrier body in addition to the adhesion or adhesive bond.

Based on Fig. 17 Now, a method for operating a rotating grinding or cutting tool is explained, in this embodiment, the Figs. 13A and 13B has known carrier body 122. The aim of the method according to the invention is to provide absorb forces occurring during operation of the tool as possible, ie with minimal component deformation. The support bodies made of fiber-reinforced composite material according to the invention can absorb high normal forces, ie the contact forces Fn without component deformation, but are susceptible to component deformation when axial forces occur, ie at feed forces Fa, depending on the design, since they do not achieve rigidity in arbitrary directions, such as isotropic materials such as steel. The operating method according to the invention now proposes that the grinding or cutting tool is pivoted in the direction of the force Fres resulting from the vector addition of contact force Fn and feed force Fa. Fig. 17 shows the vector addition and the resulting pivot angle a. During this pivoting, the resulting force Fres on the carrier body 122 acts as a pure normal load.

Claims (32)

1. A body for a rotating grinding or cutting tool, in particular a grinding wheel or grinding roller, where a coating of an abrasive material, e.g., cubic boron nitride (CBN) or diamond, can be applied to the body, characterized in that the body (2, 12, 22, 32, 42) has two spaced-apart side walls (2a, 12a, 22a, 32a, 42a; 2b, 12b, 22b, 32b, 42b) which are connected on their peripheral region, where the side walls are constructed with fibre reinforced composite, in particular carbon fibre-, glass fibre-, aramid fibre-, basalt fibre- or synthetic fibre-reinforced composite.
2. A body according to claim 1, characterized in that the fibre-reinforced composites are impregnated with a synthetic resin, where as an option, micro-fibres or nano-fibres of a strength-reinforcing material, e.g., carbon fibres, glass fibres, aramid fibres, basalt fibres, or synthetic fibres, are embedded in the synthetic resin.
3. A body according to claim 1 or 2, characterized in that the side walls are connected to each other on their peripheral region though a peripheral wall (2c, 32c) of fibre-reinforced composite.
4. A body according to any of the preceding claims, characterized in that, between the side walls, at least in sections, a core material is arranged, in particular a foam core (13), a wood core, a honeycomb core (36), preferably of aramid, or a core of mineral materials (e.g., granite).
5. A body according to any of the preceding claims, characterized in that the side walls and optionally the peripheral wall are finished as curved surfaces or free-form surfaces.
6. A body according to any of the preceding claims, characterized in that a hub (4) centrally crosses the side walls (2a, 2b).
7. A body according to any of the preceding claims, characterized in that in the body coolant and lubricant connections (7) and outlets (8) are formed, preferably with at least one coolant and lubricant connection (7) formed in a central area of one side wall, in particular in the area of the hub (4), and leading into the space (6) between the side walls, and at least one coolant and lubricant outlet (8) is created through one side wall (2a) or through the peripheral wall and through perforated or porous grinding segments.
8. A body according to any of the preceding claims, characterized in that preferably conically shaped spacer sleeves (9) going through both side walls (2a, 2b) and/or spacer pins are provided, with the spacer sleeves and/or spacer pins preferably being fixed via press fixing and/or bonding in the side walls.
9. A body according to any of the preceding claims, characterized in that the fibres of the composite are laid in the side walls or the peripheral wall based on the force path calculated for the use.
10. A body according to claim 9, characterized in that fibres dry and/or wet, i.e., soaked in the resin or impregnated with resin, are wrapped around deviating points.
11. A body according to claim 9 or 10, characterized in that fibres of the composite are arranged in the side walls running basically radial (56, 64), curved (54, 55), circular or tangential and/or elliptical from the centre of the side wall (52a, 62a) to the periphery.
12. A body according to any of the preceding claims, characterized in that fibres of the composite, at least in the area of the side walls or in the peripheral wall, are arranged in the peripheral direction.
13. A body according to any of the preceding claims, characterized in that, in the side walls, fibres (65) of the composite are arranged to run spirally from the centre to the periphery.
14. A body according to any of claims 3 to 13, characterized in that, in the peripheral wall (32c), fibres (34, 35) of the composite are arranged to run in a helical curve in axial direction.
15. A body according to any of the preceding claims, characterized in that the fibres in the side walls and optionally in the peripheral wall are arranged in several layers.
16. A body according to claim 15, characterized in that fibres of the composite are arranged in the side walls and/or optionally in the peripheral wall in cross layers.
17. A body according to any of the preceding claims, characterized in that the side walls are connected to each other by cross webs (5).
18. A body according to any of the preceding claims, characterized in that the thickness (d1, d2) of the side walls tapers from a central area towards the periphery or vice versa, at least in sections.
19. A body according to any of the preceding claims, characterized in that at least one band (12d; 22d, 22e, 22f) with unidirectional reinforcement fibres is arranged around the peripheral section.
20. A body according to any of the preceding claims, characterized in that parts of the body are stuck to each other.
21. A body according to any of the preceding claims, characterized in that the body has an integrated shaft or an impregnated spindle mantle with connection option to a drive.
22. A body according to any of the preceding claims, characterized in that the fibre-reinforced composite of the side walls and optionally of the peripheral wall is combined with energy converter materials (14, 15), such as piezo electrics, in particular piezoceramic foils and fibres, or magnetostrictive or electroactive materials, where the energy converter materials can on the one hand be optionally connected as sensor to an electrical control and on the other hand controlled by the electrical control as actuators.
23. A body according to any of the preceding claims, characterized by an inbuilt data carrier, preferably a non-contact, writable and readable data carrier.
24. A body according to claim 1, characterized in that the side walls (22a, 22b) are arranged on the peripheral region (22c) in such a way that they overlap each other across the entire peripheral region (22c).
25. A rotating grinding or cutting tool (1, 41), in particular a grinding wheel or grinding roller, with one body and a layer of abrasive material applied to one peripheral surface and/or at least one lateral surface of the body, e.g., cubic boron nitride (CBN) or diamond, characterized in that the body is designed according to one or several of claims 1 to 26.
26. A rotating grinding or cutting tool according to claim 25, characterized in that its natural frequency is adaptable or can be set to values that are above the nominal rotational frequency of the tool, with the natural frequency preferably being at least double the nominal rotational frequency and, even more preferably, at least three times the nominal rotational frequency.
27. A rotating grinding or cutting tool according to claim 25 or 26, characterized in that an electrically conductive, in particular metal ring as the basis for the galvanic applying/coating of a layer of abrasive material, in particular CBN/diamond-grinding layer, is arranged on the body.
28. A rotating grinding or cutting tool according to any of claims 25 to 27, characterized in that the body is connected to the layer of abrasive material via a guided joint, in particular dovetailing.
29. A rotating grinding or cutting tool according to claim 28, characterized in that, in a part of the guided joint, through-holes are provided to take the fibres.
30. A rotating grinding or cutting tool according to claim 25 or 26, characterized in that the body is connected to the layer of abrasive material via bonding, in particular via a thermosetting or thermoplastic adhesive.
31. A rotating grinding or cutting tool according to any of claims 25 to 30, characterized in that the layer of abrasive material is finished in one piece.
32. A method for operating a rotating grinding or cutting tool according to any of claims 25 to 31, characterized in that the grinding or cutting tool is deviated in the direction of the force resulting from the addition of vectors of clamping force and feed force.

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