Grinding disc unit for lateral surface grinding machine
The grinding disc unit with quick-action clamping and segmented cutting layers addresses the complexity of tool changes in segmented cup discs, improving productivity and maintaining quality by enabling rapid and precise tool replacement.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- ELGAN DIAMANTWERKZEUGE
- Filing Date
- 2024-06-17
- Publication Date
- 2026-07-08
AI Technical Summary
Conventional segmented cup discs require complex and time-consuming tool changes, reducing productivity when machining difficult-to-machine workpieces like coated brake discs, without maintaining machining quality.
A grinding disc unit with a segmented cup design featuring quick-action clamping devices and precise mounting areas allows for rapid tool segment replacement without adjusting position, using dovetail clamping and segmented cutting layers for improved efficiency.
Significantly reduces tool change time, enhances productivity, and maintains machining quality by eliminating the need for complex adjustments and subsequent dressing, particularly effective for coated brake discs.
Smart Images

Figure 2026522739000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a grinding disk unit used in a side surface grinding machine, and also to a side surface grinding machine provided with at least one such grinding disk unit, and a method for manufacturing the grinding disk unit.
Background Art
[0002] A side surface grinding machine can particularly be a double-sided side surface grinding machine. A double-sided grinding machine can be used, for example, to simultaneously grind substantially parallel planar circular workpiece surfaces on a disk-shaped workpiece portion of the workpiece. One applicable field is the grinding of the circular brake portion of a brake disk, particularly the coated brake disk surface.
[0003] With the strengthening of regulations regarding the emission of particulate matter from automobiles, it has been suggested that future automotive brake disks need to be designed to emit less particulate matter during braking. One approach to this is to coat the brake disk or the surface portion thereof provided as a friction surface with a thin functional layer made of a more wear-resistant material. In a coated brake disk, each surface of the circular brake portion supports a rotationally symmetric functional layer with respect to the axis of rotation, and its free surface is designed as the friction surface of the brake disk.
[0004] The manufacturing process for coated brake discs includes one or more coating steps for coating the surface of the brake portion of the brake disc with a functional layer, which needs to have a wear-reducing function due to the relatively high mechanical hardness of the individual carbides. Alternatively or additionally, it may have a corrosion-resistant effect. Often, such a functional layer is substantially composed of metal and can consist of a single layer or multiple layers having different properties. Such coatings can be applied, for example, by thermal spraying or laser cladding. Typical layer thicknesses can be, for example, in the range between 50 μm and 350 μm. The coating is generally applied to both sides. Examples of coated brake discs are disclosed in European Publication No. 2746613 and International Publication No. 2019 / 021161.
[0005] The carbides in the functional layer are generally mechanically relatively hard, and the surface of the coated layer is relatively rough. Subsequent grinding processes are intended to give the coating a sufficiently flat surface optimized for braking function. For example, the specifications for the friction surface of a brake disc are such that the central roughness Ra, measured according to DIN EN ISO 4288, is in the range of 1 μm to 3 μm-3.2 μm, and the flatness deviation does not exceed 20 μm (see International Publication No. 2021 / 224308).
[0006] In most cases, a double-sided surface grinder is used to grind brake discs.
[0007] German Patent No. 102021132468 provides a detailed description of the problem of fine dust generated by braking and specific problems when grinding brake discs with coatings that are difficult to machine. The document describes an apparatus for grinding the flat surface of a coated brake disc for automobiles, the apparatus having at least two grinding discs, the first of which is provided for extensive pre-grinding of the flat surface, and the second grinding disc is provided for slight finish grinding of the flat surface. The two grinding discs are designed as cup discs, with each disc being axially displaceable relative to the other.
[0008] German Utility Model Publication No. 202023100514 describes a double-sided surface grinder, particularly suitable for grinding both sides of brake discs, which includes a position data determination system that first determines the axial position of the workpiece surface and then determines the axial position of the polishing outer surface of the grinding disc facing the workpiece surface, relative to the same reference coordinate system. The grinding machine's control unit can control at least one grinding parameter in at least one stage of the grinding operation, according to the workpiece position data and / or tool position data. This provides the user with assistance in optimizing their own grinding process. The grinding disc is designed as a cup disc having circumferentially segmented, individually replaceable, and individually adjustable strip-shaped grinding segments.
[0009] European Publication No. 4147821 discloses, in particular, an apparatus for machining a hard-coated workpiece surface of a rotationally symmetric workpiece, which is configured in the form of a double-sided surface grinder and comprises: a workpiece drive for generating rotational motion around a workpiece rotation axis; at least one grinding disc drive for generating rotational motion around a grinding disc rotation axis; at least one feed device for bringing the grinding disc into contact with the workpiece surface; and at least one setting device for setting the grinding disc rotation axis and the workpiece rotation axis relative to each other so that the grinding disc rotation axis and the workpiece rotation axis are not parallel. The grinding disc in an exemplary embodiment is shown as a segmented cup disc. [Prior art documents] [Patent Documents]
[0010] [Patent Document 1] European Publication No. 2746613 [Patent Document 2] International Publication No. 2019 / 021161 [Patent Document 3] German patent no. 102021132468 [Patent Document 4] German Patent Application Publication No. 202023100514 [Patent Document 5] European Publication No. 4147821 [Overview of the project] [Problems that the invention aims to solve]
[0011] The problem that the present invention solves is to provide a grinding disc unit designed in the form of a segmented cup disc for use in a lateral surface grinding machine, which, by using this grinding disc unit, can improve the productivity of the grinding process, especially when grinding the surface of a workpiece that is difficult to machine, without adversely affecting the machining quality. Furthermore, the invention also provides a method for manufacturing a lateral surface grinding machine and a grinding disc unit. [Means for solving the problem]
[0012] To solve this problem, the present invention provides a grinding disc unit having the features of claim 1. Furthermore, a lateral surface grinding machine comprising at least one such grinding disc unit and a method for manufacturing a grinding disc unit are also provided. Advantageous developments are specified in the dependent claims. All claim language is incorporated herein by reference.
[0013] One aspect of the present invention provides a grinding disc unit for use in a lateral surface grinding machine. The lateral surface grinding machine has at least one tool spindle, which can be rotationally driven around a spindle axis by a spindle drive device. The term “grinding disc unit” refers to a grinding disc composed of multiple components or individual parts. The grinding disc unit has a body that defines the disk rotation axis. The body may be manufactured as a single piece or composed of multiple parts, and preferably has a mass distribution that is substantially rotationally symmetric with respect to the disk rotation axis. The grinding disc unit is mounted or can be mounted on a tool spindle such that when the body is mounted on the tool spindle, the disk rotation axis extends coaxially with the spindle axis.
[0014] The main body has a plurality of mounting areas in its periphery, offset from each other in the circumferential direction of the main body, and in each case, having devices for fastening interchangeable tool segments to the main body. The periphery is an area extending inward from the radially outer circumferential surface of the main body over a predetermined radial width. The radial width of the periphery is, for example, in the range of 2% to 20%, more specifically 2% to 10%, of the radius of the main body. The tool segments extend only over a portion of the periphery of the grinding disc unit, and this grinding disc unit may have a large number of tool segments over its periphery. The number of tool segments can be, for example, in the range of 10 to 20, but may be more or fewer.
[0015] The tool segment comprises a cutting means support having a mounting structure for fixing the cutting means support to a mounting area, and a cutting layer that forms the effective grinding surface of the tool segment on the side surface of the cutting layer. In the fully set up state of the grinding disc unit, the effective grinding surface of the cutting layer of the tool segment is substantially located on a common side surface of the grinding disc unit oriented perpendicular to the disk rotation axis, within an annular effective region of the grinding disc unit at a predetermined radial distance from the disk rotation axis. The annular effective region can be relatively narrow with respect to the radius or half diameter of the body. The annular effective region can have a width ranging from 5% to 20% of the radius or half diameter of the body, for example, measured radially. Such a grinding disc unit can also be described as a cup grinding disc having circumferentially segmented and replaceable tool segments.
[0016] This configuration has the advantage of eliminating the need to remove the entire grinding disc unit from the tool spindle and replace it with a new one, for example, when the cutting layer wears down and the tool needs replacing. Instead, only the tool segment can be replaced while the main body remains attached to the tool spindle. This concept is particularly advantageous for double-sided surface grinders, as replacing the entire grinding disc unit is generally difficult and time-consuming due to limited installation space.
[0017] Despite these design advantages, the inventors have found that, in the case of conventional segmented cup discs with replaceable tool units, replacing a tool segment with a worn cutting layer on the grinding disc unit, replacing it with a tool segment with a new cutting layer, and then restoring the grinding disc to a usable state is relatively complex and time-consuming even for a skilled machine operator. The time required for tool changes cannot be used for productive work, and if tool changes take a considerable amount of time, productivity decreases.
[0018] Herein, the invention described in the claims provides a relief that significantly reduces downtime for tool changes or improves productivity by reducing tool change time.
[0019] According to one embodiment, this is achieved in that each mounting area has a receiving device provided for receiving a tool segment and having a positioning stop surface for receiving the tool segment at a predetermined position on the main body, and further has a quick-action clamping device switchable between an open configuration and a clamped configuration, wherein in the open configuration, the tool segment can be inserted into or removed from the receiving device, and in the clamped configuration, the tool segment can be pressed against the stopper surface and fixed in a predetermined position on the main body.
[0020] In principle, this concept does not require any adjustment options that would allow the position of the mounted tool segment to be adjusted or set relative to the main body using a suitable adjustment device, such as an adjustment screw. Rather, the position of the newly mounted tool segment on the main body can be fixedly defined in several different directions, specifically with respect to the axial position (position parallel to the grinding disc rotation axis), radial position (related to the grinding disc rotation axis), tangential position, or position around the grinding disc unit, by the configuration and arrangement of the stopper surface of the receiving device on the main body and the corresponding mating surfaces on the cutting means support.
[0021] However, adjustment options can be provided as needed. This is useful, for example, for readjusting the tool segment after the tool is damaged. For example, the adjustment option can be created by forming an axially displaceable component on which the axial stop surface normally abuts against the axial stop surface of the recess of the main body, and this component is arranged between the main body and the cutting means support and is axially slightly displaceable as needed, for example by means of a suitable adjustment screw, and is used to lift the tool segment axially. It is also possible to form an inclined wedge surface on the bottom side surface of the cutting means support and / or as the axial stopper surface of the recess in the main body, and the inclined wedge surface is, for example, radially adjustable and interacts with a flat wedge element that causes axial displacement of the cutting means support relative to the main body when displaced radially, and is arranged between the cutting means support and the main body.
[0022] The quick-action clamping device only needs to operate an actuating element (one or more) having a suitable shape to switch between the open state and the clamped state, so it can be operated very quickly and easily manually or automatically (for example, using a robot or a power driver with monitoring). Thus, the tool segment can be easily replaced manually or semi-automatically by the operator. Also, the replacement of the tool segment can be carried out quickly and without problems by a simple robot.
[0023] Particularly, when machining a workpiece surface that is difficult to machine, such as in the case of a coated brake disk, this is associated with a high degree of tool wear, and the reduction in tool change time made possible by the present invention greatly contributes to improving productivity. In addition, when replacing the tool segment, there is no need to perform an adjustment operation for adjusting the position and orientation of the tool segment, so any errors caused by incorrect adjustment are systematically avoided. This contributes to improving productivity while at least maintaining the quality of the grinding result, and in some cases also contributes to improving the quality of the grinding result. <N
[0024] The clamping device is preferably configured to be switched between an open configuration and a clamping configuration by actuating a single actuating element. This is particularly convenient, for example, since an operator can operate the actuating element with one hand and handle the tool segment to be removed and attached with the other hand, which helps to quickly change the tool. Thus, one operator is sufficient. Also, a robot equipped with simple grippers and / or actuating tools can be used to quickly and problem - free change the tool segment.
[0025] According to one development, the receiving device has a recess in the body, the recess opening outwards in the radial direction (with respect to the disk rotation axis) and having at least one radial stop surface in the opposite direction (i.e., radially inwards), and also opening out in the axial direction (i.e., parallel to the grinding disk rotation axis) on the side face and having at least one axial stop surface in the opposite direction. As a result, the axial and radial positions of the tool segment relative to the body are defined by the stops and there is no possibility of adjustment. If the stop surfaces are free, the tool segment cannot be wrongly fastened to the body, i.e., in a wrong position either. This enables rapid tool changing. If necessary, chamfers can be provided on the tool segment and / or in the recess to prevent tilting during attachment.
[0026] Two or more webs that are offset from each other in the circumferential direction and have an intermediate recess are preferably provided in the region of the radial stop surface and / or the axial stop surface on the surface defining the recess, and the upper surface of the web functioning as the stop surface is manufactured with high precision. In some embodiments, the flatness of the contact surface is tolerated at a few hundredths of a millimeter, for example 0.02 mm, and the measured length with respect to the contact surface can be manufactured with the same digit of tolerance.
[0027] In a preferred embodiment, the quick-action clamping device is designed in the form of a dovetail clamping device, where the dovetail groove contour is preferably oriented so that the tool segment can be inserted into and removed from the dovetail clamping device in the axial direction of the grinding disc unit, i.e., parallel to the disc rotation axis. On the one hand, on the tool segment or its cutting means support, and on the other hand, by an interlocking structure provided on the dovetail clamping device, the inserted tool segment is secured in a bidirectional interlocking manner in the circumferential direction in the closed configuration. The tool segment is secured against machining forces on the axial stop surface of the body and additionally secured by pressure fit coupling due to clamping force. When the dovetail clamping device is closed, the tool segment is also secured bidirectionally in the radial direction, specifically first on the radially inward stop surface and then on the flank of the dovetail clamping device.
[0028] The dovetail clamping device preferably has a receiving structure having a fixed dovetail flank and an adjustable dovetail flank located on opposite sides in the circumferential direction, the dovetail flank being designed to define a dovetail groove having a groove bottom surface radially inward and narrowing radially outward.
[0029] In a dovetail clamping device, if only one flank is movable, the position of the tool segment can be defined with particularly high precision by contacting the opposite flank.
[0030] According to one development, the quick-action clamping device has a wedge-shaped clamping element that is radially movable via an actuation screw. The actuation element is preferably oriented radially and is therefore easily accessible in the radial direction, which is particularly advantageous in confined installation space environments.
[0031] Preferably, one of the wedge-shaped faces of the clamping element forms a movable flank of the associated dovetail clamping device, and the wedge-shaped clamping element is in direct contact with the cutting means support portion of the tool segment.
[0032] Embodiments in which a wedge-shaped clamping element can be moved radially inward and radially outward, i.e., bidirectionally, via a radially oriented actuation screw are particularly preferred. The actuation screw may have a right-hand thread portion and a left-hand thread portion, and turning the actuation screw clockwise results in radial movement (e.g., inward) of the wedge-shaped clamping element, while turning the actuation screw counterclockwise results in active movement in the opposite direction (e.g., radially outward). Thus, even when surfaces that come into contact with each other in the area of the clamping device are firmly fixed to each other, for example, when the wedge-shaped element is clamped and cannot be easily moved from its position, the tool segment can be quickly replaced.
[0033] The inventors have identified further methods for optimizing the process and grinding results when using segmented cup discs. One proposal provides that a tool segment has a segmented cutting layer on the side surface of a cutting layer support of a cutting means, and that this segmented cutting layer comprises at least two cutting material bodies arranged at a distance from each other. This strategy can be provided for one or more tool segments, preferably for all tool segments of a grinding disc unit. This embodiment is also referred to as “double segmentation” within the scope of this application, and the corresponding grinding disc unit is referred to as “double segmented cup disc”. It has been found that segmenting the cutting layer of a tool unit can create further degrees of freedom for optimizing the grinding process and grinding results.
[0034] A segmented cutting layer may simply comprise exactly two cutting material bodies. Preferably, a segmented cutting layer comprises three, four, five, six or more cutting material bodies. The number and configuration of individual cutting material bodies can be adapted to a wide range of machining tasks.
[0035] In a preferred embodiment, each cutting material body has a narrow effective surface defined by two longitudinal edges extending parallel or substantially parallel to each other in the longitudinal direction of the cutting material body, and a transverse edge extending laterally to the longitudinal edges, wherein the length of the effective surface measured parallel to at least one longitudinal edge between the transverse edges is several times greater than the width of the effective surface measured perpendicular to the length. The length can be, for example, at least three times the width, and the aspect ratio between length and width is often advantageous to be in the range of 3 to 6. Such narrow effective surfaces can be implemented, for example, on strip-shaped or plate-shaped cutting material bodies. As a result, relatively high surface pressure and correspondingly high machining capacity can be achieved. At the same time, liquid machining aids, such as cooling lubricants, can be introduced through the gaps between the cutting material bodies. This facilitates efficient cooling and allows for easy removal of grinding residue.
[0036] The cutting material body can be positioned on the side surface of the cutting layer of the cutting means support, and when a tool segment is attached, the cutting material body is oriented tangentially to the grinding disc unit, i.e., substantially perpendicular to the radial direction. For example, two, three, or more cutting material bodies can be provided on the side surface of the cutting layer, spaced apart from each other and arranged in a row in the front-to-back direction. It is also possible to arrange two or more rows of cutting material bodies that are radially offset from each other, extend tangentially, and have relatively narrow effective surfaces.
[0037] In particular, a modification of the tool segment having segmented cutting layers has been found to be effective for machining coated grinding discs, in which there are two or more cutting material bodies, which are spaced apart from each other and oriented obliquely to the radial and circumferential directions, and with the tool segment attached, the effective surface is not oriented tangentially or radially, but rather obliquely oriented to these two directions within the annular effective region of the grinding disc unit.
[0038] Furthermore, the present invention relates to a surface grinding machine comprising at least one grinding disc unit of the type first presented in this application.
[0039] Furthermore, the present invention relates to a method for manufacturing a grinding disc unit of the type first presented in this application. In summary, the method provides a step of simultaneously and collectively dressing the cutting layers of all tool segments of a grinding disc unit for batch machining by surface grinding, before the tool segments are subsequently separated and fastened to their respective mounting areas. Prior to the dressing, a group of tool segments is formed, including all the tool segments to be fixed to the body of the grinding disc unit. These tool segments are held together as a bundle in a certain spatial relationship with one another such that the cutting layer sides of the cutting means support are located in a common plane. Subsequently, the cutting layers of the tool segments are jointly dressed simultaneously by surface grinding after the dressing is complete, such that the effective grinding surfaces of all the cutting layers of the group of tool segments are in a common plane. As a result, immediately after the tool segments are attached to the body, the effective surfaces are already substantially in a single plane (the side of the grinding disc unit), so there is no need to perform dressing after attaching new tool segments to the body. A short conditioning period may be required to retract the binder and expose the abrasive grains so that the cutting strip is ready for cutting from the start, allowing the tool segment to resume production immediately after installation.
[0040] Further advantages and aspects of the present invention will become apparent from the description of exemplary embodiments of the present invention, which will be described below with reference to the claims and drawings. [Brief explanation of the drawing]
[0041] [Figure 1] A schematic side view is shown of an exemplary embodiment of a double-sided surface grinder, designed for grinding coated brake discs and having two segmented cup discs according to one exemplary embodiment. [Figure 2]A perspective view of one embodiment of the grinding disc unit is shown. [Figure 3] This shows a detailed enlarged view of a grinding disc unit equipped with an empty receiving device and a quick-action clamping system. [Figure 4] This shows an assembly of a dovetail-type clamping device equipped with a wedge-shaped clamping element. [Figure 5] This shows a tool segment having an oblique cutting strip that forms a segmented cutting layer. [Figure 6] A modified example of a tool segment having a protrusion on the side surface of the cutting layer of a cutting means support is shown. [Figure 7] Another variation of a tool segment having a segmented cutting layer is shown. [Modes for carrying out the invention]
[0042] Figure 1 shows a schematic side view of an exemplary embodiment of a grinding machine 100 designed to grind substantially parallel-plane circular workpiece surfaces O1, O2 on the disc-shaped workpiece portions of brake discs WS1, WS2. In this embodiment, the grinding machine is configured to grind the surface of the circular brake portion BA of a brake disc that is coated on both sides.
[0043] Each brake disc has a body made of, for example, gray cast iron, and comprises a central hub portion NA that serves to fix the brake disc to the axle, and a circular brake portion BA that surrounds the hub portion. The mass distribution of the body as a whole is rotationally symmetric with respect to the axis of rotation of the brake disc. The brake portion has two parallel surfaces (upper workpiece surface O1 and lower workpiece surface O2) that are opposite each other in the axial direction.
[0044] In the upstream stages of the manufacturing process, these surfaces are fitted with a coating or functional layer that is rotationally symmetric with respect to the axis of rotation, and the free surface of this coating or functional layer is intended to ultimately function as the friction surface of the brake disc. The coating may be very hard and may include, for example, a stainless steel alloy containing tungsten, titanium, and / or silicon carbide. In embodiments, both surfaces are coated using a special variant of laser cladding, specifically a variant of ultrafast laser cladding also known as the "EHLA process." The coating may also be applied by other methods, such as high-velocity thermal spraying (HVOF) or cold gas spraying.
[0045] The grinding machine 100 is configured as a numerically controlled rotary indexing machine comprising two workstations, specifically a loading station 110 for loading and unloading, and a grinding station 120. All functions are performed by control commands of a control unit 190 of the operation control system, which can be located locally (on or next to the machine) or remotely, for example, in another room, and in the embodiment, can be operated via an operation unit 195 equipped with a connected display and a graphical user interface.
[0046] The brake discs are transported between workstations 110 and 120 using an internal machine transport system equipped with a rotary table or turntable 150, the rotary table or turntable 150 being mounted on or within a machine base 102 so as to be rotatable around a vertical turntable axis 152, and capable of rotating indefinitely around the turntable axis using a rotary drive unit 105.
[0047] The supply station 110 is located on the left side in Figure 1. There, the first brake disc (here WS1) is supported on a workpiece spindle 154 in a horizontal orientation, i.e., with its rotation axis oriented vertically (record player configuration). Loading can be done, for example, by a robot or other handling device, or manually. Fastening can be done, for example, by clamping the brake disc in a predetermined position, or clamping it in a rotationally fixed state, and clamping it in a predetermined position on the workpiece holding device or workpiece receiving portion 155 of the workpiece spindle so that the rotation axis of the brake disc is coaxial with the rotation axis 156. Rotationally fixed coupling to the workpiece spindle can also be performed by pressing or holding from above. In the embodiment, a vertically displaceable pressing means 158 is provided.
[0048] The brake discs, thus brought in, are then transported to a working position 125 within the area of the grinding station 120 by rotating the rotary table 180° clockwise. The grinding process's work steps (one or more) are then controlled entirely automatically. At the supply station 110, the already fully ground brake discs can be simultaneously removed, and new brake discs that have not yet been ground can be clamped. Once grinding is complete, the brake discs, both fully ground, are rotated 180° and transported to the supply station 110, from where they can be unloaded, for example, by a robot or other handling device, or manually. The new brake discs to be ground can then be clamped onto the now-empty workpiece spindle, so that, except for the changeover time, both workpiece spindles are occupied by brake discs, each in a different handling stage.
[0049] The grinding machine machines the surface of a workpiece by a double-sided surface grinding process. In the grinding station 120, the grinding machine 100 has a grinding unit 121 comprising two tool spindles (an upper tool spindle 132-1 and a lower tool spindle 132-2, respectively), which are ideally arranged coaxially with each other on a frame portion, and each supports a grinding disc (an upper grinding disc 130-2 and a lower grinding disc 130-2, respectively). The grinding discs each have opposing abrasive sides 135-1 and 135-2, which are arranged to define a grinding space 133 in the axial direction. Each grinding disc can be rotated independently of other grinding discs around an associated rotating shaft 136-1 or 136-2 by an associated spindle drive or rotary drive (upper rotary drive 134-1 or lower rotary drive 134-2), and can also be fed or advanced parallel to the associated rotating shaft at a specified feed rate profile by an independent feed drive (upper feed drive 131-1 or lower feed drive 131-2).
[0050] The grinding machine 100 includes a first position measuring system 200 equipped with pneumatic distance sensors S1-1 and S2-1 for determining workpiece position data representing the axial positions of workpiece surfaces O1 and O2 at at least one surface position, relative to a reference coordinate system RKS of the machine base, and a second position measuring system 300 equipped with pneumatic distance sensors S1-2 and S2-2 for determining tool position data representing the axial positions of grinding sides 135-1 and 135-2 facing the workpiece surfaces O1 and O2, relative to the same reference coordinate system RKS. The control unit 190 can control at least one grinding parameter in at least one stage of the grinding process according to the workpiece position data and / or tool position data. The sensors can be calibrated by integrated reference elements RE1, RE2-1 and RE2-2 as needed. Details of these components and their functions are described, for example, in German Patent Publication No. 2020 23 100 514, and in this regard, the disclosures in this document are referred to.
[0051] The grinding discs 130-1 and 130-2 are designed as cup discs that are circumferentially segmented and have individually replaceable tool segments, according to the embodiment of the grinding disc unit described in this application.
[0052] Figure 2 is a perspective view of an embodiment of a grinding disc unit 400 that can be used as the upper grinding disc 130-1 and / or lower grinding disc 130-2 in the grinding machine described above. In this example, both grinding discs have the same configuration.
[0053] The grinding disc unit 400 has a body 410 having a substantially flat circular disc shape, the body 410 having a greater thickness in its outer peripheral portion 412 than the internal region surrounded by this outer peripheral portion. This peripheral portion or peripheral region is a region extending inward from the radially outer peripheral surface 413 of the body with a predetermined radial width. The radial width of the peripheral region can be, for example, less than 10% of the semidiameter of the body.
[0054] The mass distribution of the main body is rotationally symmetric with respect to the disk rotation axis 402, which extends coaxially with the spindle axis of the corresponding tool spindle when the grinding disc unit is mounted. The central through hole and further holes 411 in the internal region of the main body belong to the apparatus, and these holes allow the main body to be fixed to the tool spindle on a coaxial axis.
[0055] In this embodiment, the main body has 18 mounting areas 420 around its perimeter 412, each mounting area occupying a 20° perimeter angle area and in each case having a fastening device for fastening a replaceable tool segment 500 to the main body. The tool segments 500 are identical in configuration to each other. Figure 5 shows an enlarged view of a tool segment 500 of the type shown in Figure 2.
[0056] The tool segment 500 has a plate-shaped cutting means support 510, which can be manufactured, for example, by machining from a solid material by removing material or by an additive manufacturing process. In this embodiment, the cutting means support is made of steel. In the segment coordinate system SKS, the length of the cutting means support, measured in the longitudinal direction L, is several times greater than the width, measured perpendicular to the length in the width direction B, with the ratio being, for example, between 2:1 and 6:1, and approximately 5:1 in this embodiment. The height, measured in the height direction H, is greater than the width and less than the length, and is approximately 3 to 4 times the width.
[0057] The cutting means support 510 has a flat bottom side surface 512, an outer side surface 513 perpendicular to the bottom side surface, an inner side surface 514 located opposite the outer side surface in the width direction, and a cutting layer side surface 515 located opposite the bottom side surface, on which the cutting means support supports the cutting layer (overall reference numeral 520). The upper side surface of the cutting layer located opposite the bottom side surface forms the effective polishing surface 525 of the tool segment 500.
[0058] The effective grinding surfaces of individual tool segments are precisely located, to varying degrees, within a common plane forming the side surface of the grinding disc unit, which is oriented perpendicular to the disc rotation axis 402. Within this side surface, all effective grinding surfaces of the cutting layer are within the annular effective region 430, and the width measured in its radial direction R is only a portion of the radial range of the grinding disc unit between the disc rotation axis 402 and the outer edge, for example, 5% to 20% of this radial range. During machining of the workpiece, the grinding disc unit makes material removal contact with the workpiece surface being ground only by the grinding layer of the effective region 430. In this respect, this corresponds to the function of a conventional cup grinding disc.
[0059] The annular effective region 430 is relatively narrow with respect to the radius or half diameter of the body 410. In the embodiment, the annular effective region is measured radially and has a width in the range of 2% to 10% of the radius or half diameter of the body.
[0060] Furthermore, Figure 2 clearly shows that the annular effective region 430 protrudes radially outward beyond the circumferential surface 413 of the main body 410. Therefore, the annular effective region 430 extends outward beyond the circumferential surface of the main body. In other words, since the annular effective region 430 has an outer radius larger than the radius or half diameter of the main body, a radial projection 414 is generated. The projection 414 can be, for example, 1% or more, 2% or more, or 5% or more of the radius of the main body.
[0061] When the tool segments 500 are mounted in their respective associated mounting areas 420 around the main body 410, the longitudinal direction L of each tool segment is oriented tangentially with respect to the disk rotation axis 402, the width direction is approximately radial with respect to the disk rotation axis, and the height direction is parallel thereto. The direction extending parallel to the disk rotation axis is also referred to here as the axial direction.
[0062] The grinding disc unit 400 is particularly characterized by the fact that individual tool segments can be mounted to the main body in the correct mounting position in a very short time, and can be removed just as quickly to replace them with tool segments having a new cutting layer, if necessary. This allows for quick tool changes without removing the main body from the tool spindle. After the tool is replaced, the tool segment is positioned in a precisely defined position on the main body, so that subsequent joint dressing of the cutting layer can be omitted or some dressing can be performed in a short time. This is achieved by the specific structure or configuration of the main body in each mounting area.
[0063] The configuration of the mounting area 420 is shown particularly clearly in Figure 3, which specifically shows a side view of the mounting area, and does not show the tool segment to be mounted therein later. The mounting area contains a receiving device 440, which is basically designed as a recess in the material of the peripheral portion 412 of the main body 410, and the sides of this receiving device, which are angled relative to each other, have a specific structure and function as a stopper surface for receiving the tool segment 500 in a specified position. The recess in the main body opens outward in the radial direction R of the main body and forms a radial stopper surface 442 of the opposing side 514 of the cutting means support relative to the disk rotation axis 402. The recess opens axially to the side of the grinding disk unit but does not penetrate to the other side of the main body, but rather forms an axial stopper surface 444 at a certain distance from the top surface of the main body, which contacts the bottom side 512 of the cutting means support when the tool segment is mounted.
[0064] The radial and axial stopper surfaces are not designed as simple flat surfaces, but rather are offset several times, so that two webs are formed on each stopper surface, spaced apart from each other, and the free surfaces OB of each of these webs lie on the same plane and are machined with high mechanical precision, for example, to a flatness in the range of 0.02 mm.
[0065] As can be clearly seen from Figure 3 with the tool segment inserted, the cutting means support can be inserted such that the bottom side surface 512 of the cutting means support rests on the flat surfaces OB of the opposing webs, which are axial stopper surfaces, and there is still space between the webs and on the sides of the webs. The inwardly facing radial support surface also forms two mutually parallel webs having a corresponding appearance and coplanar upper sides, the upper sides of which function as stopper surfaces on the sides of the cutting means support.
[0066] These stopper surfaces allow for precise positioning of the inserted tool segment in both the axial and radial directions, eliminating the need for subsequent adjustments in these directions. Consequently, complex adjustment devices are unnecessary and do not need to be provided.
[0067] Precise positioning in the circumferential direction can also be achieved by contacting the stopper surface, which will be further explained below in conjunction with the description of the quick-action clamping device.
[0068] To fasten the tool segment to the main body in a defined position, each mounting area is equipped with a quick-action clamping device 470 designed as a dovetail clamping device. The quick-action clamping device acts substantially in the circumferential or tangential direction of the grinding disc unit so that the effective receiving width of the receiving device can be adjusted in the circumferential direction, allowing for a wider width to be set for the insertion and replacement of the tool segment 500, thereby enabling axial removal and insertion (open state). On the other hand, the dovetail clamping device can also be switched to a closed clamping state with a simple operation, in which case the inserted tool segment is clamped by a force component acting in the circumferential direction and as a result fixed to the main body.
[0069] For this purpose, the recess of the receiving device 440 has a stopper surface 446 that acts in the circumferential direction, is perpendicular to the axial stopper surface, and is at an angle different from 90° with respect to the radial stopper surface. The inclined surface (stopper surface 446) formed in the material of the main body functions as a fixing flank of the dovetail groove contour of the dovetail clamp device. This inclination is such that it can engage behind the inclined flank in the radial direction.
[0070] The movable part of the dovetail clamp device is located on the opposite side in the circumferential direction. This movable part comprises a wedge-shaped clamp element 460 (see Figure 4), which, in the mounted state, extends radially inward to outward and is supported by its circumferentially oriented side surface on the support surface of the main body located in the radial plane, and has a flat inclined surface 447 on the opposite side in the circumferential direction that functions as an adjustable flank of the dovetail clamp device. The fixed flank 446 and the adjustable flank located on the opposite side in the circumferential direction, together with the radial support surface, form a dovetail groove, which extends radially outward to radially inward, i.e., toward the radial contact surface 442.
[0071] Each cutting means support 510 of the inserted tool segment 500 has a corresponding bevel in the region of the end face oriented obliquely to the tangential direction, so the cutting means support of the tool segment is not exactly a cube, but rather has a trapezoidal shape in cross-section along the LB plane, being wider inward than outward in the radial direction. When the clamping device is open, if this type of tool segment is inserted into the receiving device axially from above (or below), an interlocking coupling is immediately established so that the tool segment can no longer move radially even if the clamping device is open.
[0072] The quick-action clamping device 470, configured as a dovetail clamping device, can be easily switched between an open configuration (for inserting or removing tool segments) and a clamped configuration (for securing inserted tool segments) by acting on a single actuation element. It is equally easy to release the dovetail clamping device again to remove a tool segment. This functionality is illustrated with particular reference to Figure 4, which shows a clamp assembly 472, part of the dovetail clamping device, comprising a wedge-shaped clamping element 460, an actuation screw 462, and a cylindrical fitting support element 464 extending over most of its periphery. The fitting support element 464 is inserted into a cylindrical blind hole 465 at the end of the mounting area of the main body, and has a screw hole perpendicular to its flat side, allowing the threaded end of the actuation screw 462 to be screwed into the screw hole.
[0073] The wedge-shaped clamping element 460 has a radially penetrating hole and a female thread that engages with the male thread of the operating screw 462 when the operating screw is inserted. One thread is left-hand thread and the other is right-hand thread. As a result, when the operating screw 462 is rotated in one direction (e.g. clockwise), the wedge-shaped clamping element is moved toward the mating support element, and when the operating screw is rotated in the opposite direction, the radial distance between the mating support element and the clamp wedge is necessarily increased. Consequently, even if the clamping device is stuck, such as after being engaged with a tool segment for a long time, it can be released with appropriate torque.
[0074] Replacing the tool, or more precisely, replacing the tool segment on the body of the grinding disc unit, is very easy and can be done by following these steps. The starting point is a fully mounted grinding disc unit where the grinding layer has worn down due to relatively long-term use and needs to be replaced. Therefore, the rotation of the grinding disc is stopped and the tool segment is removed in stages. To release the tool segment from the corresponding receiving device, an operator or robot only needs to rotate the operating screw 462 of the wedge-shaped clamping element in the release direction. As a result, the clamping wedge will inevitably move outward, and the dovetail-shaped clamping device will be released. The tool segment can then be removed and replaced with a new one. This tool segment can be securely fixed back into the receiving device by rotating the operating screw in the opposite direction and can be pressed against stopper surfaces acting in the axial, radial, and circumferential directions. Such tool replacement can be performed quickly for all tool segments, and therefore the tool replacement time can be significantly reduced compared to conventional solutions.
[0075] The grinding disc unit or its tool segment may be further characterized by specific features, which may be provided independently of any other grinding disc unit of the same type that allows for the rapid replacement of the tool segment.
[0076] One distinctive feature is that each of the tool segments 500 in the exemplary embodiment has a segmented cutting layer on the cutting layer side surface 515 of the cutting means support 510. The segmented cutting layer in this sense has at least two cutting material bodies arranged at a distance from each other. In this embodiment, each of the tool segments 500 has five identical cutting material bodies 522 having a relatively narrow rectangular effective surface 525. Each cutting material body contains irregularly shaped cutting particles of different shapes and sizes bonded within a bonding system. By selecting the type of cutting layer thus formed, the grinding tool can be precisely adapted to a desired machining task. The cutting particles can be, for example, diamond particles or particles made of cubic boron nitride (CBN). The cutting particles may also consist of corundum and / or other types of ceramic materials such as SiC. The binder can consist of, for example, ceramic material or synthetic resin. Metallic bonding systems, such as galvanized bonding or sintered bonding, are also possible, as is solder bonding.
[0077] In the embodiment shown in Figure 5, each of the abrasive cutting material bodies 522 is fixed onto a metallic sole 524, forming a cutting strip 530 together with the sole. The cutting material bodies can be fixed onto the sole, for example, by sintering, soldering, adhesive bonding, or by another adhesive layer. It is also possible for the cutting strip to consist only of the cutting material bodies, i.e., without a stabilizing sole.
[0078] The cutting means support 510 has a total of five rectangular receiving grooves 516 on its cutting layer side, the width of which is such that a cutting strip 530 can be inserted into the receiving groove with precision fitting and little lateral play, and can be fixed there, for example, by adhesive bonding. The receiving grooves are spaced uniformly apart from each other, and the distance measured in the width direction is approximately corresponding to the width of the receiving groove. In this embodiment, a cutting strip 530 is inserted into each of the receiving grooves 516, but in other embodiments, one or more receiving grooves are left empty to accept, for example, only three cutting strips spaced further apart from each other. The cutting means support may also have more or fewer receiving grooves, and advantageously, there should be at least three receiving grooves.
[0079] One distinctive feature here is that the receiving groove or the cutting strip to be received therein is oriented obliquely with respect to the longitudinal direction L of the cutting means support and obliquely with respect to the width direction B of the cutting means support. The acute angle SW between the width direction L of the cutting means support and the longitudinal direction LS of the cutting strip 530 is in the range of 20° to 40° in the embodiment, more specifically about 30°. This means that the longitudinal direction LS of the cutting strip having a tool segment attached to the body is oriented obliquely with respect to the radial direction R of the grinding disc unit so that it is set to approximately 20° to 40° with respect to the radial direction.
[0080] This oblique cutting arrangement has proven advantageous in many tests for several reasons, although these other orientations are also possible. For example, Figure 7 shows an embodiment of a tool segment having a segmented cutting layer, which consists of three cutting strips 530 arranged in a row relative to each other and oriented in the longitudinal direction of the cutting support, or, in the mounted state, in the tangential direction of the grinding disc unit. In other modifications, for example, only two cutting strips arranged in a row, with dimensions of 6x10x30mm (BxHxL), are provided.
[0081] Tests have shown that segmented grinding layers offer improvements over conventional non-segmented grinding layers, particularly in terms of cooling and flushing by cooling lubricants and reduced wear. The rectangular shape allows for manufacturing optimization.
[0082] In addition to the advantages of these segmented cutting layers, the oblique arrangement of the cutting means, as illustrated in Figure 5, offers further advantages. In particular, flushing by the cooling lubricant is further improved. This is due in particular to the fact that when the inclined cutting strips 530 of the grinding disc unit rotate, they act similarly to inclined turbine blades, and the rotation of the grinding disc causes the cooling lubricant to flow through the inclined intermediate space between the cutting strips, firstly cooling the cutting strips more effectively and secondly carrying away wear dust more quickly. Thus, a further reduction in wear is achieved.
[0083] Furthermore, it has been found that inclination can ensure good distribution of machining forces on the workpiece. With a cutting strip positioned substantially tangentially to the cutting disc unit, the effective area achieved radially is relatively narrow, but with an inclined cutting strip of the same width, the effective area is considerably wider due to the inclination, thereby improving load distribution. As a result, the radial cutting area is widened, and force is introduced over a larger area.
[0084] In addition, the overall effective engagement surface for a cutting strip of a particular width is substantially larger for multiple inclined cutting strips than for a tangential cutting strip of the same width. In principle, the inclination of the cutting strip also provides the possibility of fitting a relatively large number of particularly abrasive leading edges of the cutting strip when viewed from the tangential direction. Here, “leading edge” refers to the leading edge in the rotational direction of the grinding disc unit and the longitudinal edge of the cutting strip 530 that first engages with the workpiece being machined. Thus, the type of tool segment shown in Figure 5 has five leading edges of cutting bodies, each extending over a relatively large width in the radial direction (width direction).
[0085] In previous tests, machining scenarios with co-rotation and counter-rotation, as well as grinding disc units of different diameters and different cutting strip entry angles, were investigated. Under the investigated boundary conditions, an inclination of approximately 30° ± 5° (example in Figure 5) was found to be particularly suitable. While deviations from this may be favorable under other machining conditions, the acute angle SW of the grinding disc unit with respect to the radial direction should generally not exceed 45°.
[0086] In the embodiments shown in Figures 5 and 6, all cutting material bodies are set obliquely to the radial and tangential directions of the grinding disc unit via an inclination angle. However, this is not mandatory. In embodiments not shown, the inclined cutting strips are alternated with cutting strips oriented tangentially and positioned close to the outer circumference of the grinding disc unit. Such grinding disc units near the radial edge thus have a total effective surface area larger than the further internal area of the effective surface of the segmented cup disc defined by the cutting layer. Such modifications can be advantageous when machining conditions allow only a slight overrun on the area being ground by the grinding disc unit.
[0087] Some machining tasks involve surfaces that are difficult for grinding disc units to access. For example, there are brake discs where the hub portion extends from the level of the brake portion being ground, and the diameter of the hub portion at the brake portion level is smaller than the diameter at a position further axially away from it. In conventional grinding disc units, the area of the brake portion below the resulting protrusion cannot be reached because the outer circumference of the grinding disc unit collides with the upper protrusion of the hub portion when approaching the hub portion, meaning that the inner area of the brake portion is not reached by the cutting body.
[0088] According to our proposal, this type of problem can be solved by a tool segment of the type shown in Figure 6. The tool segment 600 has a cutting means support 610, which has a greater width in the portion on the cutting layer side than in the portion on the opposite end near the bottom side. In other words, the cutting means support has a projection 612 toward the cutting layer side, and the width BWW of the effective surface of the inclined cutting strip 630 (which is effective in the radial direction of the grinding disc unit) is considerably larger here than the width BS of the cutting means support at its bottom side.
[0089] When such tool segments are attached to the body of a grinding disc unit, the grinding disc unit consequently has an outer effective area on the grinding side, and this outer effective area extends further outward in the radial direction, so that the outer radius of the effective area is greater than the outer radius of the body. In other words, the effective area formed by the inclined cutting strip can extend beyond the intended axial extension of the cylindrical outer shape of the body. As a result, the grinding disc unit can reach the radially inward area of the brake portion for grinding without colliding with the hub portion of the brake disc. [Explanation of symbols]
[0090] 135-1, 135-2 Side view of the grinding disc unit 136-1, 136-2 Tool Spindle 402 Disk rotation axis 410 Main Unit 412 Surrounding area 420 mounting area 430 Annular effective region 500, 600 tool segments 510 Cutting means support 512 Bottom side 513 Exterior side 514 Internal side 515 Cutting layer side surface 520 cutting layer L Longitudinal direction B Width direction H (height direction)
Claims
1. A grinding disc unit (400) for use in a lateral surface grinding machine (100) having at least one tool spindle (132-1, 132-2) and which can be rotationally driven around a spindle axis (136-1, 136-2) by a spindle drive unit (134-1, 134-2), A disk rotation axis (402) is defined, and a body (410) is provided which is attachable to or attached to the tool spindle (136-1, 136-2) such that the disk rotation axis (402) extends coaxially with the spindle axis. The main body (410) has a plurality of mounting areas (420) in a peripheral region (412) located radially outward, the plurality of mounting areas are offset from each other in the circumferential direction of the main body, and in each case has a fastening device for fastening replaceable tool segments (500, 600) to the main body (410). The tool segment (500, 600) is a cutting means support (510) having a mounting structure for fixing the cutting means support (510) to one of the mounting areas, and a cutting layer (520) on the cutting layer side surface (515), the cutting layer forming the effective polishing surface of the tool segment. On the side surfaces (135-1, 135-2) of the grinding disc unit oriented perpendicular to the disc rotation axis, the effective polishing surface of the cutting layer is positioned within a radially outer annular effective region (430) at a predetermined radial distance from the disc rotation axis (402), thereby the grinding disc unit is designed in the form of a cup disc segmented in the circumferential direction. The mounting area (420) has a receiving device (440) equipped with stopper surfaces (442, 444) for receiving the tool segments (500, 600) in predetermined positions, and further has a quick-action clamping device (470), the quick-action clamping device (470) is switchable between an open configuration and a clamped configuration. The tool segments (500, 600) are, in the open configuration, insertable into or removable from the receiving device (440), and in the clamp configuration, the tool segments are pressed against the stopper surface and fixed in a predetermined position on the main body (410) of the grinding disc unit (400).
2. The grinding disc unit according to claim 1, wherein the quick-action clamping device (470) can be switched between the open configuration and the clamped configuration by operating a single actuation element (462).
3. The receiving device (440) is provided with a recess in the main body (410), the recess opening outward in the radial direction (R) and having at least one radial stopper surface (442) in the opposite direction, and the recess opening sideways in the axial direction and having at least one axial stopper surface (444) in the opposite direction. The grinding disc unit according to claim 1 or 2, wherein two or more webs, offset from one another in the circumferential direction and having intermediate recesses, are preferably provided in the region of the radial stopper surface (442) and / or the region of the axial stopper surface (444) on the surface that defines the recesses, and the upper surface (OB) of the webs that function as stopper surfaces is manufactured with high precision.
4. The number of the 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) and is 2% to 20% of the radial range of the grinding disk unit between the disk rotation axis (402) and the outer edge of the grinding disk 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 body; The grinding disc unit has an outer effective region on its polishing side surface, and the outer effective region extends radially outward such that the outer radius of the effective region is greater than the outer radius of the main body. A grinding disc unit according to any one of claims 1 to 3, characterized by at least one of the above.
5. The grinding disc unit according to any one of claims 1 to 4, wherein the quick-action clamping device (470) is designed in the form of a dovetail clamping device, and preferably the dovetail groove contour is oriented so that the tool segments (500, 600) can be inserted into and removed from the dovetail clamping device in a direction parallel to the disc rotation axis (402).
6. The grinding disc unit according to claim 5, wherein the dovetail clamp device (470) has a fixed dovetail flank and an adjustable dovetail flank located on opposite sides in the circumferential direction, and the dovetail flank has a groove bottom surface radially inward and defines a dovetail groove that narrows radially outward.
7. The quick-action clamping device (470) preferably has a wedge-shaped clamping element (460) that is movable in the radial direction (R) via an operating screw (462) which is preferably oriented radially, i) The wedge surface of the wedge-shaped clamping element forms a movable flank of the associated dovetail clamping device (470). ii) The wedge-shaped clamping element can be moved radially inward and radially outward by an operating screw (462), iii) The operating screw (462) has a right-hand thread portion and a left-hand thread portion, A grinding disc unit according to any one of claims 1 to 6, wherein at least one of the following features is implemented.
8. The grinding disc unit according to any one of claims 1 to 7, wherein the tool segments (500, 600) have segmented cutting layers (520) on the cutting layer side surfaces (515) of the cutting means support portions (510, 610), the segmented cutting layers comprise at least two cutting material bodies (522) arranged at a distance from each other, and the cutting layers preferably have three, four, five, six or more cutting material bodies.
9. Each of the cutting material bodies has a narrow, particularly rectangular, effective surface (525) defined by two longitudinal edges extending parallel or substantially parallel to each other in the longitudinal direction of the cutting material body and a transverse edge extending laterally with respect to the longitudinal edges, wherein the length LW of the effective surface measured parallel to the longitudinal edges between the transverse edges is several times greater than the width BW of the effective surface measured perpendicular to the longitudinal edges, and the aspect ratio between the length LW and the width BW is preferably at least 3:1 and / or in the range of 3:1 to 6:1, according to any one of claims 1 to 8.
10. The tool segment (500, 600) has at least one cutting material body (525), the cutting material body being oriented obliquely with respect to the radial direction (R) and tangential direction (T) of the grinding disc unit (400) when the tool segment is attached, and the longitudinal direction of the effective surface is not oriented in either the tangential or radial direction, but rather obliquely with respect to these two directions within the annular effective region (430) of the grinding disc unit. The grinding disc unit according to any one of claims 1 to 9, wherein the tool segments (500, 600) preferably have two or more cutting material bodies (525), the cutting material bodies are arranged at a distance from each other and are oriented obliquely to the radial and tangential directions of the grinding disc unit when the tool segments are mounted.
11. The grinding disc unit according to claim 10, wherein the longitudinal direction (LS) of the obliquely oriented cutting material body (522) includes an acute angle (SW) of up to 45° with respect to the radial direction (R) of the grinding disc unit, and the angle is preferably in the range of 15° to 40°, particularly about 30°.
12. The grinding disc unit according to any one of claims 1 to 11, wherein the main body has a circumferential surface located within the minimum circumscribed circle coaxial with the disk rotation axis, the cutting means support portion of the tool segment has a projection on the side surface of the cutting layer such that, when the tool segment is attached, the cutting layer protrudes radially beyond the minimum circumscribed circle by an overrun width, and the annular effective surface of the grinding disc unit, defined by the effective surface of the cutting layer, preferably has an outer radius larger than the radius of the main body.
13. A lateral surface grinder (100) for grinding a substantially flat workpiece surface on a workpiece portion (WA) of a workpiece (WS1, WS2), and a double-sided surface grinder for grinding the workpiece surface of a circular brake portion of a brake disc, A grinding unit (121) having at least one tool spindle (132-1, 132-2), supporting a grinding disc (130-1, 130-2) having abrasive surfaces (135-1, 135-2), wherein the grinding disc can be rotated around an assigned rotation axis (136-1, 136-2) by associated rotational drive devices (134-1, 134-2), and can be fed parallel to the associated rotation axis by feed devices (131-1, 131-2), At least one workpiece spindle (154) having a workpiece receiving portion (155) for receiving the workpieces (WS1, WS2) in a rotatably fixed manner, wherein the workpiece receiving portion is rotatable by a rotary drive device (157) around a rotation axis (156) extending parallel or obliquely to the rotation axis of the grinding disc, and the at least one workpiece spindle (154) is positioned in a working position during at least one stage of the grinding operation such that the workpiece portion (WA) of the received workpiece is in contact with the grinding surface, Equipped with, A grinding machine wherein the grinding disc is designed as a grinding disc unit (400) according to any one of claims 1 to 12.
14. A method for manufacturing a grinding disc unit according to any one of claims 1 to 12, The steps include forming a group of tool segments from all tool segments fixed to the main body such that the tool segments are held in a certain spatial relationship with each other and the cutting layer sides are located on a common plane, The steps include: co-dressing all the cutting layers of the tool segments of the tool segment group by surface grinding so that the polishing effective surfaces of all the cut bodies become a common plane; The steps include: incorporating the tool segment into the associated receiving device on the main body; A method that includes this.