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EP-4739455-A1 - GRINDING DISC UNIT FOR A LATERAL SURFACE GRINDING MACHINE

EP4739455A1EP 4739455 A1EP4739455 A1EP 4739455A1EP-4739455-A1

Abstract

The invention relates to a grinding disc unit (400) for use in a lateral surface grinding machine, comprising a main part (410) which defines a disc rotational axis (402) and which is installed or can be installed on a tool spindle such that the disc rotational axis (402) runs coaxially to the spindle axis, wherein a circumferential region (412) of the main part (410) has a plurality of installation regions (420) which are offset to one another in the circumferential direction of the main part and which comprise securing devices for securing a respective exchangeable tool segment (500) to the main part (410). A tool segment (500) has a cutting means support (510), which comprises installation structures for securing the cutting means support in one of the installation regions, and a cutting fitting (520) on a cutting fitting side, said cutting fitting forming an abrasive functional surface of the tool segment. The abrasive functional surfaces of the cutting fittings are arranged on a lateral surface of the grinding disc unit, said lateral surface being oriented perpendicularly to the disc rotational axis, within an annular functional region (430) at a radial distance to the disc rotational axis (402). At least one tool segment has a segmented cutting fitting (520) on the cutting fitting side of the cutting means support, said segmented cutting fitting comprising at least two cutting material bodies which are arranged in a mutually spaced manner.

Inventors

  • Duda, Sebastian
  • Dzivenko, Dmytro
  • KRANICHSFELD, Florian
  • Neumann, Nick
  • WITT, THOMAS

Assignees

  • Elgan-Diamantwerkzeuge GmbH & Co. Kg

Dates

Publication Date
20260513
Application Date
20240617

Claims (14)

  1. 1. Grinding wheel unit (400) for use in a side face grinding machine (100) having at least one tool spindle (132-1, 132-2) which can be driven in rotation about a spindle axis (136-1, 136-2) by means of a spindle drive (134-1, 134-2), comprising: a base body (410) which defines a wheel rotation axis (402) and is mountable or mounted on the tool spindle (136-1, 136-2) such that the wheel rotation axis (402) runs coaxially to the spindle axis; wherein the base body (410) has, in a radially outer peripheral region (412), a plurality of mounting regions (420) arranged offset from one another in the peripheral direction of the base body, with fastening devices for fastening a respective exchangeable tool segment (500, 600) to the base body (410); wherein a tool segment (500, 600) has a cutting means carrier (510) with mounting structures for fastening the cutting means carrier in one of the mounting areas and a cutting coating (520) on a cutting coating side (515), which forms an abrasive active surface of the tool segment, wherein the abrasive active surfaces of the cutting coatings are arranged in a side surface (135-1, 135-2) of the grinding wheel unit oriented perpendicular to the wheel rotation axis within a radially outer annular active region (430) with a radial distance from the wheel rotation axis (402), so that the grinding wheel unit is designed in the manner of a cup wheel segmented in the circumferential direction, characterized in that at least one tool segment on the cutting coating side (515) of the cutting means carrier (510) has a segmented cutting coating (520) which has at least two cutting material bodies arranged at a mutual distance from one another (522) includes.
  2. 2. Grinding wheel unit according to claim 1, characterized in that the cutting coating (520) has three, four, five, six or more cutting material bodies (522).
  3. 3. Grinding wheel unit according to claim 1 or 2, characterized in that the cutting material bodies (522) each have a narrow, in particular rectangular, effective surface (525) which is delimited by two longitudinal edges running parallel (or almost parallel) to one another in the longitudinal direction of the cutting material body and transverse edges running transversely to the longitudinal edges, wherein a length LW of the effective surface measured parallel to the longitudinal edges between the transverse edges is several times greater than a width measured perpendicular to the longitudinal edges BW of the effective area, wherein preferably an aspect ratio between the length LW and the width BW is at least 3:1 and/or is in the range from 3:1 to 6:1.
  4. 4. Grinding wheel unit according to one of the preceding claims, characterized in that a tool segment (500, 600) has at least one cutting material body (525) which, in the assembled state of the tool segment, is oriented obliquely to the radial direction (R) and obliquely to the tangential direction (T) of the grinding wheel unit (400) in such a way that the longitudinal direction of the effective surface within the annular effective area (430) of the grinding wheel unit is neither tangential nor radial, but obliquely to these two directions,
  5. 5. Grinding wheel unit according to claim 4, characterized in that a tool segment (500, 600) has two or more cutting material bodies (525) arranged at a mutual distance from one another, which, in the assembled state of the tool segment, are oriented obliquely to the radial direction and obliquely to the tangential direction of the grinding wheel unit.
  6. 6. Grinding wheel unit according to claim 4 or 5, characterized in that a longitudinal direction (LS) of an obliquely oriented cutting material body (522) encloses an acute angle (SW) of a maximum of 45° with a radial direction (R) of the grinding wheel unit, wherein the angle is preferably in the range from 15° to 40°, in particular approximately 30°.
  7. 7. Grinding wheel unit according to one of the preceding claims, characterized in that the base body has a circumferential surface which lies within a minimum enveloping circle coaxial with the wheel rotation axis and that the cutting means carriers of the tool segments have a projection (612) on the cutting coating side such that when the tool segment is mounted, the cutting coating projects in the radial direction by an overflow width beyond the minimum enveloping circle, wherein preferably an annular effective surface of the grinding wheel unit defined by the effective surfaces of the cutting coatings has an outer radius which is larger than the radius of the base body.
  8. 8. Grinding wheel unit according to one of the preceding claims, characterized in that an assembly area (420) has a receiving device (440) with stop surfaces (442, 444) for positionally defined receiving of a tool segment (500, 600) and a quick-clamping device (470) which can be switched between an open configuration and a clamping configuration, wherein in the open configuration a tool segment (500, 600) can be inserted into the receiving device (440) or removed from the The receiving device can be removed and in the clamping configuration the tool segment is pressed against the stop surfaces and can be fixed in a predetermined position on the base body (410).
  9. 9. Grinding wheel unit according to claim 8, characterized in that the quick-clamping device (470) can be switched between the open configuration and the clamping configuration by actuating a single actuating element (462).
  10. 10. Grinding wheel unit according to claim 8 or 9, characterized in that a receiving device (440) comprises a recess in the base body (410), wherein the recess is open to the outside in the radial direction (R) and has at least one radial stop surface (442) in the opposite direction and is open towards the side surface in the axial direction and has at least one axial stop surface (444) in the opposite direction, wherein preferably in the region of a radial stop surface (442) and/or in the region of an axial stop surface (444) on the surfaces delimiting the recess, two or more webs offset from one another in the circumferential direction with recessed sections in between are provided, wherein the upper sides (OB) of the webs serving as stop surfaces are manufactured with high precision.
  11. 11. Grinding wheel unit according to one of claims 8 to 10, characterized in that the quick-clamping device (470) is designed in the manner of a dovetail clamping device, wherein preferably a dovetail contour is oriented such that the tool segment (500, 600) can be inserted and removed from the dovetail clamping device in a direction parallel to the wheel rotation axis (402), wherein preferably the dovetail clamping device (470) has a fixed dovetail flank and an adjustable dovetail flank opposite in the circumferential direction and the dovetail flanks delimit a dovetail groove which has a radially inner groove bottom surface and narrows radially outwards.
  12. 12. Grinding wheel unit according to one of claims 8 to 11, characterized in that the quick-clamping device (470) has a wedge-shaped clamping element (460) which is movable in the radial direction (R) via an actuating screw (462) which is preferably aligned in the radial direction, wherein preferably at least one of the following features is realized: i) a wedge surface of the wedge-shaped clamping element forms a movable flank of an associated dovetail clamping device (470) ii) the wedge-shaped clamping element can be moved both radially inwards and radially outwards by means of the actuating screw (462), iii) the actuating screw (462) has a section with a right-hand thread and a section with a left-hand thread.
  13. 13. Grinding wheel unit according to one of the preceding claims, characterized by at least one of the following features: a number of tool segments (500, 600) is in the range of 10 to 20; the annular effective region (430) has a width measured in the radial direction (R) that is 2% to 20% of the radial extent of the grinding wheel unit between the wheel rotation axis (402) and an outer edge of the grinding wheel unit; the annular effective region (430) has a width measured in the radial direction (R) that is 2% to 20% of the radius of the base body; the grinding wheel unit has an external effective region on the abrasive side surface that extends outwards in the radial direction such that the outer radius of the effective region is larger than the outer radius of the base body.
  14. 14. Side face grinding machine (100) for grinding a substantially flat workpiece surface on a workpiece section (WA) of a workpiece (WS1, WS2), in particular a double-side face grinding machine for grinding workpiece surfaces of a circular brake section of a brake disk, comprising a grinding unit (121) with at least one tool spindle (132-1, 132-2) which carries a grinding disk (130-1, 130-2) with an abrasive side surface (135-1, 135-2), wherein the grinding disk can be rotated about the associated rotation axis (136-1, 136-2) by means of an associated rotation drive (134-1, 134-2) and can be fed parallel to the associated rotation axis by means of a feed drive (131-1, 131-2), at least one workpiece spindle (154) with a workpiece holder (155) for the rotationally fixed reception of the workpiece (WS1, WS2), wherein the workpiece holder is rotatable by means of a rotary drive (157) about a rotation axis (156) running parallel or obliquely to the rotation axis of the grinding wheel and is arranged in a working position at least during a phase of a grinding operation such that the workpiece section (WA) of the received workpiece comes into contact with the abrasive side surface, characterized in that the grinding wheel is designed as a grinding wheel unit (400) according to one of the preceding claims.

Description

Grinding wheel unit for a side face grinding machine FIELD OF APPLICATION AND STATE OF THE ART The invention relates to a grinding wheel unit for use in a side face grinding machine and to a side face grinding machine equipped with at least one such grinding wheel unit. The side face grinding machine can in particular be a double side face grinding machine. Double side face grinding machines can be used, for example, for grinding essentially plane-parallel, circular workpiece surfaces on a disk-shaped workpiece section of a workpiece. One possible area of application is the grinding of surfaces of a circular brake section of a brake disk, in particular a coated brake disk. Upcoming tightening of the regulations on fine particle emissions from motor vehicles means that future brake discs for motor vehicles will have to be designed in such a way that fewer fine particles are released during braking. One approach to this is to coat the brake discs or their surface sections intended as friction surfaces with a thin functional layer made of more wear-resistant material. In a coated brake disc, the surfaces of the annular braking section each have a functional layer that is rotationally symmetrical with respect to the axis of rotation, the free surface of which is designed as the friction surface of the brake disc. The manufacturing process of a coated brake disc comprises one or more coating operations for coating the surfaces of the brake section of the brake disc with a functional layer that is intended to have a wear-reducing function due to its relatively high mechanical hardness. Alternatively or additionally, a corrosion-inhibiting effect can also be present. Such functional layers often consist essentially of metal; they can have a single layer or several layers with different properties. Such coatings can be applied, for example, by flame spraying or laser cladding. Typical layer thicknesses can be in the range between 50 pm and 350 pm, for example. The coatings are usually applied on both sides. The documents EP 2 746 613 A2 and WO 2019/021161 A1 disclose examples of coated brake discs. The carbides of the functional layers are usually mechanically relatively hard and the layers are relatively rough on the surface after coating. A subsequent grinding process is intended to produce a sufficiently flat surface on the coating that is optimized for the braking function. The specifications for friction surfaces of a brake disc can, for example, be such that a mean roughness Ra determined in accordance with DIN EN ISO 4288 should be in the range of 1 m to 3 pm - 3.2 pm and a flatness deviation should be no more than 20 pm (cf. WO 2021/224308 A). Double-sided face grinding machines are often used for grinding brake discs. The document DE 102021 132468 B3 contains a detailed description of fine dust problems caused by braking and specific problems in the grinding of brake discs that have a coating that is difficult to machine. A device for grinding flat sides of a coated brake disc for a motor vehicle is described, wherein the device has at least two grinding wheels, of which a first grinding wheel is provided for pre-grinding the flat side by a large allowance and a second grinding wheel is provided for finish-grinding the flat side by a small allowance. The two grinding wheels are designed as cup wheels that can be moved axially relative to one another and lie one inside the other. The document DE 20 2023 100 514 U1 describes, among other things, a double-sided surface grinding machine suitable for grinding brake discs on both sides, which Position data determination systems are included which determine, on the one hand, the axial position of the workpiece surface and, on the other hand, the axial position of the abrasive side surface of a grinding wheel facing the workpiece surface in relation to the same reference coordinate system. A control unit of the grinding machine can control at least one grinding parameter in at least one phase of the grinding operation depending on the workpiece position data and/or the tool position data. This gives a user a tool for optimizing "his" grinding process. The grinding wheels are designed as cup wheels segmented in the circumferential direction with individually replaceable and individually adjustable strip-shaped grinding segments. The document EP 4 147 821 A1 discloses a device, designed in the manner of a double-side surface grinding machine, for machining a hard-coated workpiece surface of a rotationally symmetrical workpiece, comprising a workpiece drive device for generating a rotational movement about a Workpiece rotation axis, at least one grinding wheel drive device for generating a rotational movement about a grinding wheel rotation axis, at least one feed device for bringing the grinding wheel into contact with the workpiece surface and at least one adjustment device for adjusting the grinding wheel rotation axis and the workpiece rotation axis to one anot