Method and apparatus for grinding elongated workpieces

Abstract

The invention relates to a method for grinding an elongated workpiece (14), comprising the following steps: - clamping the workpiece (14), wherein the workpiece (14) is supported at a first workpiece end (82) in a first workpiece holder (12) by means of a first centering device (44) and at a second workpiece end (84) in a second workpiece holder (78) by means of a second centering device (80); - carrying out a first grinding step at at least a first section of a lateral surface of the workpiece (14) by means of a tool assembly (18); - switching the clamped workpiece (14), wherein the workpiece (14) is released from the first centering device (44) and the second centering device (80) and one of the workpiece ends (82, 84) is held in the first workpiece holder (12); and - carrying out a second grinding step at a second section of the lateral surface of the workpiece (14) by means of the tool assembly (18), wherein a support device (69) supports the workpiece (14) on at least one portion of the lateral surface of the workpiece (14).

Description

Technical Field

[0001] This invention relates to a method and apparatus for grinding slender workpieces. Background Technology

[0002] Workpieces can be ground in different ways. In the case of rotationally symmetrical, elongated workpieces, it is usually necessary to first shape the workpiece blank into a rotationally symmetrical form so that further grinding operations can be performed on the workpiece subsequently. For rotationally symmetrical grinding of the blank, it is advantageous to support the workpiece via its end faces, so that the entire lateral surface of the workpiece can be freely machined.

[0003] In rotationally symmetric workpieces, where the ratio of workpiece length to diameter is particularly large or increased due to material removal during grinding, and the workpiece is to be ground up to its first end, it is known that the workpiece is supported only at its second end in a workpiece holder and also supported by supports on the lateral surface of the workpiece near the tool. Therefore, it is possible to apply the pressure necessary for grinding to the workpiece using the grinding tool while simultaneously ensuring sufficient support near the workpiece to withstand the pressure. This avoids deviations from the desired workpiece profile.

[0004] DE 694 21 859T2 discloses a grinding machine for cutting rotationally symmetric workpieces, wherein the ratio of the workpiece length to its diameter is large. A spindle carrying the workpiece is mounted on a frame via a spindle head, allowing it to move relative to two opposing grinding discs along the longitudinal axis of the workpiece. Furthermore, supports for supporting the workpiece on its lateral surfaces are fixedly arranged on the frame. To grind the rotationally symmetric workpiece to a predetermined diameter, the workpiece and grinding discs are rotated, and the workpiece is moved relative to the frame via the spindle head and along the workpiece axis in the direction of the grinding discs.

[0005] The different grinding operations described above are usually performed on different grinding equipment, which are designed for each grinding process.

[0006] However, the investment cost of various grinding equipment is high. This is particularly disadvantageous when dealing with a small number of pieces. Furthermore, the large number of grinding machines required for a workpiece typically results in a long production time for that workpiece.

[0007] Therefore, there is a need to provide grinding processes that are both time-efficient and simple for slender workpieces. Summary of the Invention

[0008] This objective is achieved by the method according to claim 1. Furthermore, this objective is also achieved by the apparatus according to claim 12. The dependent claims relate to advantageous modifications of the invention.

[0009] The method for grinding slender workpieces according to the present invention includes the following steps:

[0010] - Clamping the workpiece, wherein the workpiece is supported in a first workpiece holder at a first workpiece end by means of a first centering device, and supported in a second workpiece holder at a second workpiece end by means of a second centering device;

[0011] - Perform a first grinding step on at least a first section of the side surface of the workpiece using a tool assembly;

[0012] - The workpiece is switched and clamped, wherein the workpiece is disengaged from the first and second centering devices, and one end of the workpiece is received in the first workpiece holder; and

[0013] - A second grinding step is performed on a second section of the side surface of the workpiece using a tool assembly, wherein a support device supports the workpiece on at least a portion of the side surface of the workpiece.

[0014] Clamping the workpiece at its end allows for flexible machining, particularly on its entire side surface. Furthermore, despite unevenness in the side surfaces, the workpiece can be supported by a workpiece holder. This means that even if the workpiece initially has a non-rotationally symmetric shape about its longitudinal axis, the workpiece with the longitudinal axis can be easily clamped and supported.

[0015] Using a centering device ensures that the clamped workpiece is positioned relative to the workpiece holder and thus also relative to the tool assembly. In other words, using a centering device ensures that the workpiece has a defined longitudinal axis about which it is rotationally symmetrical. The workpiece can rotate about this longitudinal axis.

[0016] The desired geometry or external profile can be produced in a first section of the workpiece using the first grinding step. For the first grinding step, the entire side surface of the workpiece is available because the workpiece is supported via its ends. The side surface extends between the two ends of the workpiece. During the first grinding step, the support device is not in contact with the workpiece or does not support the workpiece.

[0017] The workpiece is ensured to no longer contact the centering device by changing the clamping mechanism. Furthermore, the workpiece is no longer supported by the second workpiece holder. For example, depending on the orientation of the workpiece held in the first workpiece holder, the area on the workpiece side surface associated with the second workpiece end can be flexibly machined if the workpiece is not directly supported by a supporting device there. This is particularly advantageous for rotationally symmetrical workpieces that require machining up to one end. Defined support of the workpiece can be achieved by holding one end of the workpiece in the first workpiece holder. It can be specified that the first workpiece holder holds and supports the workpiece in the area on the workpiece side surface corresponding to the first or second workpiece end. This achieves reliable holding and support in the first workpiece holder. After the workpiece side surface has been machined at least in the first section during the first grinding step, the workpiece can be held there to support it in a defined manner.

[0018] Because of the support device that holds the workpiece during the second grinding step, even relatively long and thin workpieces can be processed. The forces generated during grinding are received via the support device, effectively preventing workpiece bending. This means that even workpieces with a particularly large length-to-diameter ratio can be processed with high precision.

[0019] Overall, the method according to the invention provides efficient grinding of elongated workpieces.

[0020] According to another improvement of the invention, during clamping, the workpiece is coupled to a first centering device via a centering portion of the workpiece's axial end face and / or, in particular, an inclined surface adjacent to the axial end face of the workpiece, and / or via another centering portion of the workpiece's other axial end face and / or, in particular, an inclined surface adjacent to the other axial end face of the workpiece, to a second centering device. This allows the entire side surface of the workpiece to be substantially or completely freely machined. Simultaneously, the workpiece is supported in a defined manner. Advantageously, the two end faces are arranged parallel to each other within the clamping zone. If the two end faces are not arranged parallel to each other, it can be specified that the end faces of the workpiece can be machined in a previous machining step such that these end faces are parallel to each other. The term "axial" generally refers to the direction along the longitudinal axis of the workpiece.

[0021] According to one aspect of the invention, during the first grinding step, the first workpiece holder is brought close to the tool assembly at a first speed. Therefore, simple machining along the first section can be achieved. Alternatively, during the first grinding step, the first workpiece holder is moved away from the tool assembly at a first speed.

[0022] According to one design of the present invention, during the first grinding step, the support device approaches the tool assembly at a second speed.

[0023] According to one aspect of the invention, the second speed may be less than the first speed. This causes the support device to gradually approach the first workpiece holder.

[0024] According to another improvement of the invention, the first and / or second grinding steps may include peel grinding.

[0025] According to one aspect of the invention, the workpiece may be ground into a rotationally symmetrical shape in a first section, at least in the first grinding step. Rotational symmetry relates to the longitudinal axis of the workpiece. This is advantageous for further grinding and allows the workpiece to be held in a defined manner in a first workpiece holder during clamping changes.

[0026] According to one embodiment of the invention, the first section may comprise the entire side surface of the workpiece. Therefore, complete grinding of the side surface of the workpiece can be achieved in the first grinding step. This simplifies the operation, subsequent grinding steps, and subsequent support.

[0027] According to one aspect of the invention, during the change clamping process, the workpiece is supported on its side surface by means of a support device before and / or during disengagement, and in particular, the workpiece is clamped by means of the support device. Therefore, a defined position of the workpiece during the change clamping process can be achieved. Clamping prevents undesirable skewing or slippage of the workpiece. The workpiece can be reliably held.

[0028] According to another improvement of the invention, a gripper is provided to hold the first centering device. During the changeover clamping, the gripper holds the first centering device and removes it from the area between the first workpiece holder and the end of the first workpiece. Therefore, it is sufficient for the first workpiece holder and the workpiece to only need to translate relative to each other along a defined axis. Thus, a simple and time-saving changeover clamping can be achieved overall.

[0029] According to one design of the present invention, the second section may be arranged within or corresponding to the first section. Therefore, it is possible to process the area of ​​the workpiece's side surface that has previously been processed in the first grinding step by means of a second grinding step.

[0030] According to another improvement of the invention, the tool assembly is offsetly engaged with the workpiece relative to the engagement area of ​​the support device in the direction of the workpiece's longitudinal axis, particularly on the side of the support device opposite to the first workpiece holder. Due to this offset, a large engagement area can be achieved on the workpiece for the workpiece holder. Simultaneously, no grinding occurs at the location where the support device simultaneously supports the workpiece. This ensures reliable support using the support device. The offset can be specified to be small relative to the workpiece length, for example, 1 / 20, 1 / 30, or 1 / 40. This allows the forces generated by grinding to be absorbed through the support device as a good or short force flow in the workpiece. Workpiece deformation or bending due to grinding can be avoided or at least reduced. The aim is to process the workpiece with the tool assembly as close as possible to the support device.

[0031] According to the present invention, during the first grinding step and / or the second grinding step, the workpiece is moved relative to the support device along the longitudinal axis of the workpiece. In this case, at least during the second grinding step, the workpiece can be movably or slidably supported on the support device along the longitudinal axis of the workpiece.

[0032] According to another improvement of the invention, the support device and the tool assembly are spaced apart from each other at a constant distance during the second grinding step.

[0033] Alternatively, according to one aspect of the invention, the support device may be positioned at a fixed location on the workpiece relative to the longitudinal axis of the workpiece, at least during the second grinding step. Then, the support device also moves simultaneously with the first workpiece holder in the direction of the longitudinal axis of the workpiece.

[0034] According to another improvement in the alternative approach, the distance between the support device and the tool assembly changes, preferably decreases, during the second grinding step. Overall, this alternative design achieves so-called "fliegend" machining, where the length of the workpiece to be machined can freely contact the workpiece during the second grinding step without being affected by the support device. This is particularly advantageous when producing non-rotationally symmetric configurations or profiles on the workpiece and / or when the second grinding step is repeated multiple times.

[0035] According to one aspect of the invention, the tool assembly may be oriented at least partially different from that of the first grinding step during the second grinding step. Therefore, for example, it is possible to achieve a different grinding mode relative to the first grinding step even though the same tool or the same plurality of tools are engaged with the workpiece.

[0036] According to another improvement of the invention, in the second grinding step, a region of the first workpiece side surface is ground to a first workpiece diameter, and a region of the second workpiece side surface is ground to a second workpiece diameter, wherein the first diameter is smaller than the second diameter. It can be specified that the second workpiece side surface is arranged closer to the first workpiece holder than the first workpiece side surface. It can also be specified that regions of the third, fourth, and other side surfaces of the workpiece are ground to corresponding diameters. All diameters, or some of the diameters, can be different. It can be specified that the diameter decreases or increases with the distance from the first workpiece holder.

[0037] According to another aspect of the invention, it can be specified that, in the second grinding step, a variable diameter, particularly a constant diameter along the longitudinal axis of the workpiece or a diameter extending according to a function, is formed in a region of the side surface of the first workpiece.

[0038] According to another improvement of the invention, at least one of the two workpiece holders, particularly the first workpiece holder, includes a rotatably driven workpiece spindle, and the workpiece is rotatably driven by the rotatably driven workpiece spindle at least during the first and second grinding steps. This rotatable drive occurs about the longitudinal axis of the workpiece.

[0039] According to one aspect of the invention, it can be specified that at least one workpiece diameter in the first section is measured after the first grinding step and / or at least one workpiece diameter in the second section is measured after the second grinding step. Therefore, it is possible to check whether the workpiece has reached a preset size. If the preset size has not been reached, it can be specified that, for example, the first or second grinding step is repeated.

[0040] According to another improvement of the present invention, the measurement may be repeated at least once, and the first grinding step may be repeated if necessary, until the workpiece reaches the preset size.

[0041] Furthermore, according to one aspect of the invention, it can be specified that the workpiece length, particularly the position of the first or second workpiece end, is measured after the clamping change. Whether the position of the first or second workpiece end is measured depends on the orientation of the workpiece received in the first workpiece holder. In other words, it is advantageous to measure the position of the workpiece end facing away from the first workpiece holder. This may be necessary in order to perform the second grinding step with high precision and to begin the second grinding step directly at the first or second workpiece end.

[0042] The aforementioned measurements can be performed using appropriate measuring devices or common measuring devices, especially measuring instruments.

[0043] The aforementioned methods and / or further improvements thereof can be advantageously implemented on a single device, particularly on grinding equipment.

[0044] According to another improvement of the invention, the elongated workpiece may be specified to have a non-rotationally symmetric shape at least in the second section after the second grinding step, wherein the non-rotationally symmetric shape of the elongated workpiece is preferably produced by means of the second grinding step. It may be specified that the elongated workpiece has a polygonal, elliptical, or other arbitrarily complex shape after the second grinding step. This can be achieved, in particular, by means of coordinated movement of the workpiece relative to the tool assembly in the direction of the workpiece's longitudinal axis.

[0045] Furthermore, the objective according to the invention is achieved by an apparatus for grinding elongated workpieces, wherein the apparatus comprises:

[0046] - A first workpiece retainer for supporting the workpiece via a first workpiece end and a second workpiece retainer for supporting the workpiece via a second workpiece end;

[0047] - Tool assemblies for grinding workpieces;

[0048] - A support device for supporting a workpiece at least in stages via at least a portion of the side surface of the workpiece; wherein the device is arranged to implement a method according to any of the foregoing types.

[0049] The workpiece holder can support the workpiece individually and collectively via the workpiece end. Support via the workpiece end means that the workpiece can be connected directly or via an intermediate component, such as via a centering device, to the respective workpiece holder.

[0050] According to another improvement of the invention, the support device may include a support with a support groove. The support groove can be used to hold the workpiece, but still allows the workpiece to move relative to the support device in the direction of its longitudinal axis. To improve the sliding motion of the workpiece relative to the support groove, the support groove may be made of or coated with a material with a low coefficient of friction.

[0051] According to another design embodiment of the invention, the support can be height-adjustable in the direction perpendicular to the longitudinal axis of the workpiece. Therefore, the support device can support the workpiece regardless of its diameter.

[0052] According to one aspect of the invention, the support device further includes a clamping device, particularly a clamping roller, arranged opposite the support, wherein the support device supports the workpiece between the support and the clamping device. The clamping device ensures that the workpiece is reliably held on the support, particularly in the support groove. Furthermore, the clamping roller allows the workpiece to rotate relative to the support device during support.

[0053] According to another improvement of the invention, the support device is arranged on a support carriage, which is designed to be movable relative to the tool assembly and relative to the first workpiece holder along the support carriage direction. Here, the support carriage direction corresponds to the longitudinal axis of the workpiece at least during the first or second grinding step. This mobility allows the workpiece to be easily clamped by the auxiliary switching of the support device and also easily supported during the second grinding step.

[0054] According to one design of the present invention, the tool assembly has a first tool spindle capable of rotational drive including a first grinding tool and a second tool spindle capable of rotational drive including a second grinding tool.

[0055] According to the present invention, the first grinding tool may include a coarse grinding disc and / or the second grinding tool may include a fine grinding disc. Therefore, different grinding processes, particularly with different surface roughnesses, can be achieved.

[0056] Furthermore, according to the present invention, the workpiece may be arranged between the first and second grinding tools during the grinding process.

[0057] Furthermore, according to the invention, during the first and / or second grinding steps, the contact area between the first grinding tool and the workpiece is arranged closer to the first workpiece holder than the contact area between the second grinding tool and the workpiece. Therefore, the contact point is offset about the longitudinal axis of the workpiece. Thus, in conjunction with the relative movement of the workpiece relative to the tool assembly, the first grinding operation is achieved by means of the first grinding tool, and the subsequent second grinding operation is achieved by means of the second grinding tool. Therefore, overall, efficient grinding of the workpiece can be achieved. This is particularly advantageous when the first grinding tool is designed as a coarse grinding disc and the second grinding tool is designed as a fine grinding disc.

[0058] According to another improvement of the invention, a first grinding tool is arranged on a first tool carriage, and a second grinding tool is arranged on a second tool carriage, so that the tools move in a translational direction perpendicular to the longitudinal axis of the workpiece and perpendicular to the height direction. Therefore, it is possible to easily match the wear on the grinding tool or the material removal from the workpiece.

[0059] According to one embodiment of the invention, the first tool carriage and / or the second tool carriage are further arranged on a rotary device for rotating the grinding tool about the rotation axis of the tool carriage, wherein the rotation axis of the tool carriage is oriented in the height direction, i.e., perpendicular to the longitudinal axis of the workpiece and perpendicular to the translation direction. This allows the first or second grinding tool to engage with the workpiece in different orientations.

[0060] According to an improved embodiment of the present invention, during the second grinding step, the first grinding tool rotates by a certain angle relative to the first grinding step around the first rotation axis.

[0061] According to an improved embodiment of the invention, the apparatus for grinding may further include a workpiece hopper and a workpiece holder for holding the workpiece, wherein the workpiece holder is configured to transport the workpiece between positions between the workpiece hopper and the workpiece holder.

[0062] According to one improved embodiment, the workpiece holder may include at least two workpiece holder arms for holding the workpiece. This allows the workpiece holder to hold, for example, a workpiece to be processed in one workpiece arm while simultaneously holding a processed workpiece in the other workpiece arm.

[0063] According to one aspect of the invention, an apparatus for grinding includes: a guide carriage with a first workpiece holder disposed on it; and a workpiece holder carriage with a second workpiece holder disposed on it, wherein the guide carriage is movable along a workpiece carriage direction, and the workpiece holder carriage is movable along a workpiece holder carriage direction. The workpiece carriage direction and the workpiece holder carriage direction can be parallel or the same as each other. This allows the workpiece holder to hold workpieces of different lengths. Furthermore, it enables different positions of the workpiece relative to the grinding tool.

[0064] According to one improvement, a first workpiece holder can be arranged on a carriage that allows the first workpiece holder to be displaced in the height direction. This height direction is preferably oriented perpendicular to the longitudinal axis of the workpiece or perpendicular to the direction of the workpiece carriage. Therefore, even if the support cannot be displaced in the height direction, workpieces of different diameters can be machined during a second grinding step on a grinding machine. Alternatively or additionally, a second workpiece holder can also be arranged on another such carriage.

[0065] According to another improvement of the present invention, the equipment for grinding further includes a control unit for controlling the equipment.

[0066] It is generally important to note that the features, designs, or advantages described in relation to the method of this invention also apply to the device. Therefore, the features of the method can be implemented through the device and, in particular, embodied in the features of the device, without requiring an explicit description of the device features. Conversely, the same applies; that is, the features of the device also apply to the method. Attached Figure Description

[0067] The invention will now be described in detail with reference to the accompanying drawings. The drawings show:

[0068] Figure 1A perspective view of a device according to an embodiment of the present invention is shown;

[0069] Figure 2 A detailed perspective view of a device according to an embodiment of the present invention is shown;

[0070] Figure 3 Another detailed perspective view of the device according to an embodiment of the invention is shown;

[0071] Figure 4 Another detailed perspective view of the device according to an embodiment of the invention is shown;

[0072] Figure 5 Another detailed perspective view of the device according to an embodiment of the invention is shown;

[0073] Figure 6 Another detailed perspective view of the device according to an embodiment of the invention is shown;

[0074] Figure 7 Another detailed diagram of the device according to an embodiment of the invention is shown;

[0075] Figure 8 Another detailed perspective view of the device according to an embodiment of the invention is shown;

[0076] Figure 9 Another detailed perspective view of the device according to an embodiment of the invention is shown;

[0077] Figure 10 Another detailed perspective view of the device according to an embodiment of the invention is shown;

[0078] Figure 11a A cross-sectional view of the centering device according to the first embodiment is shown;

[0079] Figure 11b A cross-sectional view of the centering device according to the second embodiment is shown;

[0080] Figure 12a A simplified detailed diagram of the device according to the invention is shown;

[0081] Figure 12b A simplified detailed diagram of the device according to the invention is shown;

[0082] Figure 13a A simplified detailed diagram of the device according to the invention is shown;

[0083] Figure 13b A simplified detailed diagram of the device according to the invention is shown;

[0084] Figure 14a A simplified detailed diagram of a device according to the invention is shown, which performs grinding steps in a varied manner; and

[0085] Figure 14b A simplified detailed diagram of a device according to the invention is shown, which performs grinding steps in a varied manner. Detailed Implementation

[0086] Figure 1 A view of an apparatus 10 for grinding operations according to an embodiment of the present invention is shown. The apparatus 10 includes a first workpiece holder 12 in which a workpiece 14 is held, and the first workpiece holder 12 includes a rotatably driven workpiece spindle 16 that carries the workpiece 14. Furthermore, the apparatus 10 includes a tool assembly 18 comprising a rotatably driven first tool spindle 20 and a rotatably driven second tool spindle 24, a first grinding tool 22 disposed in the rotatably driven first tool spindle 20, and a second grinding tool 26 disposed in the rotatably driven second tool spindle 24. Additionally, the apparatus 10 includes a support device 69, which is only partially visible here and is partially obscured by the tool assembly 18. A clamping roller 72 on a clamping arm 74, which is part of the support device 69, is visible. The support device 69 will be shown in more detail in conjunction with other figures. Furthermore, the apparatus 10 includes a hopper 28 with other workpieces 14'. A workpiece holder 30 is also formed on the device 10.

[0087] A first workpiece holder 12 is arranged on a first guide carriage 32, which is movable along two tracks 36 of a first carriage guide 34 in the height direction Z1. A second guide carriage 38 is then formed on the first carriage guide 34, and is arranged to move along a second carriage guide 39 formed on the base 40 of the device 10. In other words, the first carriage guide 34 can move together with the first workpiece holder 12 along the first workpiece carriage direction X1 by means of the second guide carriage 38 and the second carriage guide 39. When the workpiece 14 is held in the workpiece holder 12, the first workpiece carriage direction X1 coincides with the longitudinal axis W of the workpiece.

[0088] Furthermore, a gripper 42 for holding the first centering device 44 or the workpiece 14 is arranged on the first workpiece holder 12. The gripper 42 is designed to insert and remove the first centering device 44 into and from the workpiece spindle 16 of the first workpiece holder 12. For this purpose, the gripper 42 is capable of rotating about a rotation axis C2, which extends in the height direction Z1, by means of a gripper actuator 46. Furthermore, the gripper 42 is coupled to the first workpiece holder 12 by means of a gripper carriage assembly 47. The gripper carriage assembly 47 allows the gripper 42 to move on the first workpiece holder 12 along a gripper carriage direction X5, which is parallel to the first workpiece carriage direction X1. Additionally, the gripper 42 includes an actuable gripper clamp 43 by means of which the gripper 42 holds the first centering device 44 or the workpiece 14.

[0089] The workpiece spindle 16, capable of rotational drive, is configured to drive the workpiece 14 to rotate about the workpiece rotation axis A1. The workpiece rotation axis A1 extends parallel to the direction X1 of the first workpiece carriage.

[0090] The tool assembly 18 includes a first tool carriage 48, on which a first tool spindle 20 is formed, and the first tool carriage 48 is movable relative to the base 40 in a first tool carriage direction Y2. The first tool carriage direction Y2 is perpendicular to the height direction Z1 and perpendicular to the first workpiece carriage direction X1. The tool assembly 18 also includes a second tool carriage 50, on which a second tool spindle 24 is disposed, and which is movable relative to the base 40 in a second tool carriage direction Y1 independently of the first tool carriage 48. The second tool carriage direction Y1 is parallel to the first tool carriage direction Y2.

[0091] Furthermore, the first tool carriage 48 is rotatable relative to the base 40 about a tool carriage rotation axis C1 via a pivoting device 49, wherein the tool carriage rotation axis C1 is oriented parallel to the height direction Z1 and perpendicular to the first tool carriage direction Y2. The first tool spindle 20 drives the first grinding tool 22 about a first tool spindle rotation axis A2, which is perpendicular to the tool carriage rotation axis C1. As the first tool carriage 48 rotates, the orientation of the first tool spindle rotation axis A2 can change in space and relative to the base 40. Here, the first tool spindle rotation axis A2 is arranged parallel to the first workpiece carriage direction X1. The second tool spindle 24 drives the second grinding tool 26 about a second tool spindle rotation axis A3, which is also arranged parallel to the first workpiece carriage direction X1.

[0092] The workpiece holder 30 is connected to the base 40 via a connector assembly 52 on the workpiece holder carriage assembly 54. The connector assembly 52 allows the workpiece holder 30 to rotate relative to the workpiece holder carriage assembly 54 about the workpiece holder rotation axis B1. The workpiece holder rotation axis B1 is arranged parallel to the two tool carriage directions Y2, Y1 or perpendicular to the height direction Z1 and the workpiece carriage direction X1. The workpiece holder carriage assembly 54 allows the workpiece holder 30 to move relative to the base 40 in a direction Z2 parallel to the height direction Z1 and in another direction Y3. The other direction Y3 is arranged parallel to the tool carriage directions Y2 and Y1 or perpendicular to the height direction Z1 and the workpiece carriage direction X1.

[0093] The hopper 28 is arranged on the hopper carriage assembly 56, which is configured to move the hopper 28 along the hopper carriage direction X4. The hopper carriage direction X4 is arranged parallel to the workpiece carriage direction X1 or perpendicular to the height direction Z1 and another direction Y3. The hopper carriage assembly 56 allows the hopper 28 to be positioned relative to the workpiece holder 30, enabling the workpiece holder 30 to remove or insert workpieces into the hopper 28. The other workpieces 14' shown are vertically inserted, i.e., along the height direction Z1, into the holes of each hopper tray 58. Six hopper trays 58 are provided, each rectangular in shape and having twenty holes 60 for inserting workpieces.

[0094] A second workpiece holder 78 is centrally arranged within the tool assembly 18, between the first tool spindle 20 and the second tool spindle 24, opposite to the first tool holder 12. The second workpiece holder 78 is shown partially obscured here and will be described in more detail below.

[0095] The device 10 includes a base 40 and a frame 66, on which other components of the device 10 are arranged or formed. The base 40 is substantially cubic in shape. For example, a second guide carriage 38 is arranged on one side of the base and a workpiece holder carriage assembly 54 including a gripper 30 is arranged on the other side. The base 40 and the frame 66 are connected to each other near the bottom. The frame 66 is formed as an elongated support structure on which a tool assembly 18, a support device 69, a second workpiece holder 78 are formed on a first portion of the frame 66 and a hopper 28 is formed on an adjacent second portion of the frame 66.

[0096] The following is shown Figures 2 to 10 This is used to illustrate and explain the various steps of the method according to the invention. The apparatus 10 may be shown simplified in these figures to present the various steps of the method in a simple and understandable manner. Figures 2 to 10The same device 10 is shown in the figures, and these figures are constructed or illustrate sequential steps or brief descriptions of the method.

[0097] Figure 2 Detailed views of a device 10 according to an embodiment of the invention are shown, wherein, relative to Figure 1 The device 10 is shown in a simplified manner. The workpiece holder 30 holds the workpiece 14 using a first workpiece holder arm 62, where the workpiece 14 is not yet machined, and the workpiece holder 30 holds the machined workpiece 14 using a second workpiece holder arm 64. The longitudinal axis W of the workpiece 14 is shown for the workpiece 14; since the workpiece 14 is not yet clamped, the longitudinal axis W is not yet aligned with the workpiece carriage direction X1. For simplicity, the workpiece holder 30 is shown floating freely and therefore not coupled to the base 40.

[0098] Furthermore, the rotatably driven workpiece spindle 16 of the first workpiece holder 12 is empty, i.e., there are no workpieces 14, 14” and no first centering device 44 installed in the first workpiece holder 12. However, the gripper 42 is prepared to hold the first centering device 44 and feed it to the workpiece spindle 16.

[0099] Figure 2 Tool assembly 18 is also shown; however, tool assembly 18 is in a ready mode and is not engaged or machined with any workpieces 14, 14”. The first grinding tool 22, inserted into the first tool spindle 20, is designed as a coarse grinding disc. The second grinding tool 26, inserted into the second tool spindle 24, is designed as a fine grinding disc. The first tool carriage 48 is shown rotating about the tool carriage rotation axis C1. (The last sentence appears to be incomplete and possibly refers to a different document.) Figure 1 As can be seen, a support carriage 65 is also arranged on the frame 66 coupled to the base 40 as described above. The support carriage 65 is movable relative to the frame 66 in the support carriage direction X2 along a support carriage assembly (not shown in detail here). Furthermore, three guide posts 67 are arranged on the support carriage 65, such as those for... Figure 12aA more detailed illustration is provided. A support 68 with a support groove 70 is formed on the support carriage 65, which is a support device 69. The support groove 70 is formed as a V-shaped groove in the support 68. The support 68 can also be referred to as a fixed bracket. Furthermore, a clamping roller 72 is arranged above the support 68, which, as part of the support device 69, is rotatably connected at one end to a clamping arm 74, which is directly connected to the support carriage 65. The clamping arm 74 is coupled at its other end to an actuator 76, which in turn couples the clamping arm 74 to the support carriage 65. The actuator 76 is designed to move the clamping arm 74 in the height direction Z1. This allows the clamping roller 72 to press the workpiece into or release it from the support groove 70 of the support 68, i.e., without applying pressure to the workpiece. Here, the clamping roller 72 is arranged spaced apart from the support groove 70 and no workpiece is arranged in or between the clamping roller 72 and the support groove 70.

[0100] Furthermore, on the frame 66, a second workpiece holder 78 is arranged on a workpiece holder carriage (not shown in detail here), as if combined with... Figure 12a The workpiece holder carriage is described in more detail. The workpiece holder carriage is movable relative to the support carriage 65 along the workpiece holder carriage direction X3. Here, the workpiece holder carriage, together with the workpiece holder 78, is displaced on three guide posts 67. The guide posts 67 are fixedly coupled to the support carriage 65. The workpiece holder carriage direction X3 is parallel to the first workpiece carriage direction X1. With the aid of the workpiece holder carriage, the second workpiece holder 78 can be moved away from or towards the first workpiece holder 12. Furthermore, the second workpiece holder 78 can be displaced relative to the tool assembly 18 even when its distance relative to the first workpiece holder 12 remains constant. This is particularly important during the grinding of the workpiece 14. A second centering device 80 is rotatably held in the second workpiece holder 78 about the workpiece rotation axis A1. The second centering device 80 is arranged on the side of the second workpiece holder 78 facing the first workpiece holder 12. Furthermore, the hopper 28 is at least partially shown.

[0101] Figure 3 Another detailed view of the device 10 according to one embodiment of the invention is shown. (Comparison) Figure 2As can be seen, the first centering device 44 is held within the workpiece spindle 16 of the first workpiece holder 12. Furthermore, the workpiece 14 is coupled to the first centering device 44 and centered relative to the first workpiece rotation axis A1 via the first centering device 44. The gripper 42 no longer holds the first centering device 44, as the first centering device 44 is surrounded and supported by the workpiece spindle 16. However, the gripper now holds the workpiece 14 to hold it in place. The workpiece 14 is no longer held by the workpiece gripper 30. Instead, the gripper 42 presses the first workpiece end 82 of the workpiece 14 against the first centering device 44. The second workpiece end 84 of the workpiece 14 floats freely and is not yet coupled to the second centering device 80. Therefore, the workpiece 14 is held in place only by the gripper 42 and by contact with the first centering device 44.

[0102] Figure 4 Another detailed view of the device 10 according to one embodiment of the invention is shown. Here, workpiece 14 is shown as... Figure 3 The image shows a state where the workpiece 14 is coupled to and centered via the first centering device 44. Furthermore, the workpiece 14 is held in place by the gripper 42 and pressed against the first centering device 44. (As shown in...) Figure 3 As shown, the second workpiece end 84 is not yet coupled to the second centering device 80 of the second workpiece holder 78. However, the second workpiece end 84 is about to be coupled to the second centering device 80. For this purpose, the workpiece 14 is moved via the gripper 42 and the first workpiece holder 12 in the direction of the first workpiece carriage X1 by means of a second guide carriage 38 (not shown here). In addition, the support carriage 65 and the workpiece holder carriage 78 are moved in the direction of the workpiece spindle 16 (X3 direction).

[0103] The workpiece 14 is arranged in the support groove 70 of the support 68, but above and spaced apart from the support 68 by about 1 to 3 mm. Therefore, in this method step, no support is achieved by the support 68. The pressure roller 72 is arranged above and spaced apart from the workpiece 14, so no pressure is applied to the workpiece 14 in the direction of the support 68.

[0104] Figure 5 Another detailed view of the device 10 according to one embodiment of the invention is shown, wherein the pressure roller 72 and pressure arm 74 are not shown for better presentation. (Comparison) Figure 4 Workpiece 14 is coupled not only to the first centering device 44 but also to the second centering device 80, and is centered and supported by it about the workpiece rotation axis A1. Thus, workpiece 14 is clamped between the two workpiece holders 12, 78.

[0105] Compared to Figure 4The gripper 42 is now disengaged from the workpiece 14 and also from the first centering device 44 and is in a ready position. The support 68 and the clamping roller 72 (not shown here) are as described. Figure 4 The workpiece 14 remains in contact with the workpiece 14 at its ends only by means of the corresponding centering devices 44, 80 in the corresponding workpiece holders 12, 78.

[0106] The workpiece 14 is driven to rotate by the workpiece spindle 16 and rotates about the workpiece rotation axis A1. The unprocessed workpiece 14 is already largely cylindrical, but does not precisely correspond to a cylindrical shape or has an excessively large diameter or unevenness along its side surfaces.

[0107] exist Figure 5 In this process, tool assembly 18 performs the first grinding step. For this purpose, workpiece 14 is driven to rotate as described previously. Furthermore, a first grinding tool 22, designed with a coarse grinding disc, contacts workpiece 14 on one side with the side surface 86 of the coarse grinding disc. The first grinding tool 22 is driven to rotate by means of a first tool spindle 20 about a first tool spindle rotation axis A2. The coarse grinding disc has a relatively high surface roughness. Material is removed from workpiece 14 due to the relative movement and contact between the first grinding tool 22 and workpiece 14.

[0108] Furthermore, for the first grinding step, a second grinding tool 26, designed as a fine grinding disc, is rotated and driven by a second tool spindle 24 about a second tool spindle rotation axis A3. The second grinding tool 26 contacts the workpiece 14 on the other side of the first grinding tool 22. The fine grinding disc has a smaller, but still sufficient, surface roughness compared to the coarse grinding disc. Material is removed from the workpiece 14 due to the relative movement and contact between the second grinding tool 26 and the workpiece 14. The second grinding tool 26 has a contact area with the workpiece 14 that is further away from the first workpiece holder 12 along the first workpiece carriage direction X1 than the contact area between the first grinding tool 22 and the workpiece 14. Furthermore, the workpiece 14 is displaced along the first workpiece carriage direction X1 such that the workpiece 14 is ground along its entire side surface from the second workpiece end 84 to the first workpiece end 82 by both grinding tools 22 and 26. Due to the distance between the two contact areas and the relative movement of the workpiece 14 with respect to the grinding tools 22 and 26, it is possible to perform rough grinding with a coarse grinding disc and then fine grinding with a fine grinding disc.

[0109] Figure 6 Another detailed view of the device 10 according to one embodiment of the invention is shown. Compared to Figure 5Workpiece 14 has been fully ground on its entire side surface from the second workpiece end 84 to the first workpiece end 82 by means of the first grinding step. Therefore, the first grinding step is now completed and workpiece 14 is cylindrical, and thus workpiece 14 is rotationally symmetrical with respect to the workpiece longitudinal axis that coincides with the workpiece rotation axis A1. The two grinding tools 22, 26 are no longer in contact with workpiece 14.

[0110] Before workpiece 14 is clamped, its diameter is measured along its side surface. For this purpose, a first measuring device 88, consisting of two parallel measuring arms 90 arranged on a support carriage 65, contacts the side surface of workpiece 14. Simultaneously, workpiece 14 is displaced relative to the first measuring device 88 in the first workpiece carriage direction X1, and is rotated around its rotation axis A1 by means of a workpiece spindle 16. Therefore, the diameter is measured along the side surface of workpiece 14 from the first workpiece end 82 to the second workpiece end 84. This measurement allows verification of whether a predetermined workpiece diameter and rotational symmetry of workpiece 14 have been achieved. If not, the first grinding step can be repeated at least for a specific section of the side surface of workpiece 14.

[0111] Figure 7 Another detailed view of the device 10 according to one embodiment of the invention is shown. At least one sub-step of clamping the workpiece 14 is shown here. The workpiece 14 is no longer driven to rotate. The first measuring device 88 is now back in the ready position and is not touching the workpiece 14. Compared to Figure 6 It can be seen that the actuator 76 pushes the clamping arm 74 downward and now presses the workpiece 14 into the support groove 70 by means of the clamping roller 72. Therefore, the workpiece 14 can be held in place by means of the support device 69 alone. The workpiece 14 is coupled to the device 10 by means of the support device 69 alone.

[0112] Compared to Figure 6As can be seen, both workpiece holders 12 and 78 are spaced apart from the workpiece 14. To this end, the first workpiece holder 12 is first moved together with the workpiece 14 in the direction of the support groove 70 (X1 direction). Then, the gripper 42 is rotated toward the workpiece 14, so that the gripper 42 holds the workpiece 14. Then, the workpiece 14 is separated from the workpiece holder 78 by the movement of the workpiece holder 78 (X3 direction), so that the tool 14 is initially held only by the first workpiece holder 12 and the gripper 42. Then, the carriage 32 is lowered in the Z1 direction, and therefore also by the workpiece holder 12 and the gripper 42, until the workpiece contacts the support groove 70. Then, the clamping roller 72 is brought into contact with the workpiece 14 by the actuation of the actuator 76, so that the workpiece is clamped between the support groove 70 and the clamping roller. Then, the gripper 42 is removed from the workpiece, and also the first workpiece holder 12 is removed from the workpiece 14 along the first workpiece carriage direction X1, and therefore also from the second workpiece holder 78. Furthermore, the support device 69 is displaced (in the X2 direction) by means of the support carriage 65 arranged on the frame 66, that is, displaced in the direction of the first workpiece holder 12. Thus, the workpiece is now held only by clamping between the clamping roller 72 and the support groove 70. Then the gripper 42 holds around the first centering device 44, and after there is no longer contact between the first workpiece end 82 and the first centering device 44, the gripper 42 removes the first centering device 44 from the area between the first workpiece end 82 and the workpiece spindle 16, thereby disengaging the first centering device 44 from the workpiece spindle 16.

[0113] Figure 8 Another detailed view of the device 10 according to one embodiment of the invention is shown. Compared to Figure 7 As can be seen, workpiece 14 is now clamped in the first support device 12 or in the workpiece spindle 16. The clamping of workpiece 14 is switched such that at least a portion of the side surface of workpiece 14 contacts the workpiece spindle 16. Therefore, workpiece 14 is now mounted in the first support device 12 such that the workpiece has a defined position along the workpiece rotation axis A1 and cannot be tilted. Therefore, at least a slight lateral force on workpiece 14 in the direction transverse to the longitudinal axis of the workpiece can be absorbed by the first support device 12, and the support device 69 does not apply a supporting effect to workpiece 14. Here, workpiece 14 is not in contact with the support device 69.

[0114] Due to the change clamping in the first support device 12, it is necessary to determine the precise position of the workpiece 14 in the device 10. For this purpose, a second measuring device 94, in the form of a measuring instrument, is provided on the support carriage 65. To this end, the measuring head 96 of the measuring device 94 is brought to the vicinity of the second workpiece end 84, more specifically, to the area in front of the second workpiece end 84. Then, the workpiece 14 is moved toward the measuring head 96 along the first workpiece carriage direction X1 by means of the guide carriage 38 until the second workpiece end 84 contacts the measuring head 96. Thus, the position of the workpiece 14 or the second workpiece end 84 with respect to the first workpiece carriage direction X is determined, thereby enabling grinding to begin on the side surface of the workpiece 14 at the second workpiece end 84.

[0115] Figure 9 Another detailed view of the device 10 according to one embodiment of the invention is shown. Figure 9 The image shows the execution of the second grinding process. It can be seen that, compared to the first grinding step, the first grinding tool 22 now rotates approximately 90 degrees counterclockwise around the tool carriage rotation axis C1 when viewed from above. This is not absolutely necessary, but it improves the removal of material from the workpiece 14.

[0116] Workpiece 14 is driven to rotate by workpiece spindle 16 about workpiece rotation axis A1. Workpiece 14 rests against support groove 70 on support 68 and is pressed into support groove 70 by clamping roller 72. Compared to the first grinding step, the second workpiece end 84 is no longer coupled to the second workpiece holder 78, but is spaced apart from it. This allows workpiece 14 to be freely machined at the second workpiece end 84. During the second grinding step, two grinding tools 22, 26 contact the workpiece. The second grinding tool 26 again has a contact area with workpiece 14, which is located further away from the first workpiece holder 12 in the direction of the first workpiece carriage X1 than the contact area between the first grinding tool 22 and workpiece 14. Furthermore, workpiece 14 is displaced in the direction of the first workpiece carriage X1, such that workpiece 14 is ground along its side surface from the second workpiece end 84 to a desired area near or towards the first workpiece end 82 by the two grinding tools 22, 26 (machining length dx1). Due to the distance between the two contact areas and the relative movement of the workpiece 14 with respect to the grinding tools 22 and 26, it is possible to perform rough grinding with a coarse grinding disc and then fine grinding with a fine grinding disc.

[0117] Here, the two grinding tools 22 and 26 move by means of their respective tool carriages 48 and 50, causing the workpiece 14 to be machined to a predetermined workpiece diameter. Here, the workpiece 14 is ground to a first workpiece diameter in a section of its side surface corresponding to the second workpiece end 84, and ground to a second workpiece diameter in a section of its side surface adjacent to the section above it in the direction towards the first workpiece end 82, wherein the first workpiece diameter is smaller than the second workpiece diameter. This can also be done differently, for example, in the opposite direction. (In the following...) Figure 10 The Chinese will see this more clearly.

[0118] In the second grinding step, the workpiece diameter is significantly reduced. Simultaneously, forces are applied to the workpiece 14 by the grinding tools 22 and 26. To at least partially withstand these forces and achieve high machining quality, a support device 69 is arranged near the contact area of ​​the two grinding tools 22 and 26 during the second grinding step. The contact area is preferably no more than 10 mm, particularly preferably no more than 5 mm, but at least 0.5 mm, from the contact area between the support device 69 and the workpiece 14. Specifically, the support device 69 is arranged in the area between the first workpiece holder 12 and the two grinding tools 22 and 26.

[0119] During the second grinding step, the two grinding tools 22, 26 and the support device 69 are fixed in position relative to the frame 66 and do not move relative to each other. The workpiece 14 is moved along the first workpiece carriage direction X1 in the direction of the two grinding tools 22, 26 and the support device 69 by means of two tool holders 12, 78.

[0120] Figure 10 Another detailed view of the device 10 according to one embodiment of the invention is shown. Figure 9 The second grinding step is now complete. The finished workpiece 14 is no longer in contact with the two grinding tools 22, 26 and the support device 69, but is supported or held only by the first workpiece holder 12. It can be seen that, based on the second grinding step, the workpiece 14 has a first workpiece diameter in the section of its side surface adjacent to the second workpiece end 84 (i.e., the first workpiece side surface 98), which is smaller than the second workpiece diameter. This second workpiece diameter is formed on another section of the side surface of the workpiece 14, i.e., the second workpiece side surface 100, in the direction immediately following this section in the direction of the first workpiece end 82. In the workpiece spindle 16 and in the region adjacent to the workpiece spindle 16, i.e., the third workpiece side surface 102, the workpiece 14 is not processed by the second grinding step, but only by the first grinding step.

[0121] To check the second grinding step, the workpiece diameter is measured again using the first measuring device 88. For this purpose, the first measuring device 88, having two measuring arms 90 arranged parallel to each other, contacts the side surface of the workpiece 14. Simultaneously, the workpiece 14 is displaced relative to the first measuring device 88 in the direction of the first workpiece carriage X1 and is rotated about the workpiece rotation axis A1 by means of the workpiece spindle 16. Therefore, the workpiece diameter is measured at least in the area of ​​the side surface of the workpiece 14 processed by the second grinding step. The measurement allows verification that a predetermined workpiece diameter and rotational symmetry of the workpiece 14 have been achieved in the corresponding section of the side surface. If this is not achieved, the second grinding step can be repeated at least for the specific section of the side surface of the workpiece 14.

[0122] Another major kinematic advantage is the Z1 axis. It moves X2, Y1, and Y2 relative to the frame 66. The first guide carriage 32 (in the Z1 direction) specifically carries the workpiece rotation axis A1 and the workpiece spindle 16. This allows the workpiece 14 to be moved onto the support 68 for support after the first grinding step. This enables the use of a fixedly mounted support with high precision and rigidity. Furthermore, this degree of freedom allows for compensation for wear on the support 68. Moreover, in the second grinding step, different workpiece diameters can be machined within the geometry of the support 68. For this, only the first guide carriage (Z1 axis) needs to be moved accordingly. In practice, the support 68 is designed with replaceable inserts.

[0123] Once the measurement is successfully completed, another workpiece 14' can be ground. For this purpose, the other workpiece 14' has been held in place by the workpiece holder 30. Workpiece changeover can be performed as follows: Figure 2 The grinding process can be performed as shown in the diagram. Figures 2 to 10 The process is repeated as shown.

[0124] Figure 11a A cross-sectional view of a first centering device 44 according to a first embodiment is shown. Here, the first centering device 44 is received in and supported by a first workpiece holder 12 via a portion of its side surface. It can be seen that the first workpiece holder 12 includes a clamping device 104, not shown in detail. A V-shaped recess 106 is formed on the side of the first centering device 44 opposite to the first workpiece holder 12, wherein the recess 106 has a circumferential centering surface 108 adjacent to and inclined relative to the side surface of the first centering device 44 and a blind hole 110.

[0125] Figure 11a Workpiece 14 is also shown, wherein the workpiece has a circumferential ramp 112 at its first workpiece end 82. Workpiece 14 is coupled to a portion of a circumferential centering surface 108 by means of the circumferential ramp 112, thereby supporting and centering the workpiece. Figure 11a The details shown in the middle are based on Figures 1 to 10 This can also be achieved in other embodiments. For completeness, it should be made clear that, for the sake of simplicity, workpiece 14 is only partially shown on the side opposite to the first workpiece holder 12.

[0126] Figure 11b A cross-sectional view of the first centering device 44 according to the second embodiment is shown. (As shown in...) Figure 11a Similarly, the first centering device 44 is also received in and supported by the first workpiece holder 12 via a portion of its side surface. It can be seen that the first workpiece holder 12 includes a clamping device 104, which is not shown in detail.

[0127] A V-shaped tip 114 with a circumferential centering surface 116 is formed on the side of the first centering device 44 facing away from the first workpiece holder 12. A V-shaped centering hole 118 is formed at the first workpiece end 82 of the workpiece 14, at the center of the workpiece 14, i.e., on the workpiece axis W. The tip 114 engages in the centering hole 118. Therefore, the workpiece 14 is supported and centered in the first workpiece holder 12.

[0128] Figure 12a A simplified detailed diagram of the device 10 according to the invention is shown, in which only the various components of the device 10 are shown. It can be seen that the support carriage 65 is coupled to the frame 66 by means of a support carriage assembly 120 and is therefore movable relative to the frame 66 in the support carriage direction X2. The support carriage assembly 120 includes at least two tracks 121 arranged on the support carriage 65, the tracks 121 being guided in track guides 123 attached to the frame 66 and thus guiding the support carriage 65. The arrangement of the tracks 121 and track guides 123 relative to the support carriage 65 and the frame 66 may also be reversed. Furthermore, to facilitate the displacement of the support carriage 65 in the X2 direction, a threaded spindle (not shown) is provided in the support carriage assembly 120.

[0129] Three guide posts 67 are attached to the support carriage 65, allowing the second workpiece holder 78 to be displaced on the guide posts along the workpiece holder carriage direction X3 via the workpiece holder carriage 121. The workpiece carriage direction X3 and the support carriage direction X2 are arranged parallel to each other. The guide posts 67 are coupled to the stop member 122 on the side opposite to the support carriage 65.

[0130] An actuator 124 in the form of a pneumatic cylinder is also shown between the guide posts 67. The actuator 124 can be actuated, thereby displacing the second workpiece holder 78 along the workpiece holder carriage direction X3 on the guide posts 67. Due to the design of the actuator 124, as will also be combined with... Figure 12bAs clearly shown, without clamping the workpiece 14, it can only approach the end position on the guide post 67, i.e., on the support carriage 65 or the stop 122. Instead of a design with a pneumatic cylinder, the actuator 124 can also be implemented, for example, by means of a threaded spindle or a servo drive.

[0131] The support carriage 65 is also provided with a clamping arm 74 including a clamping roller 72, an actuator 76, and a support 68.

[0132] Figure 12b A simplified cross-sectional view of the device 10 according to the invention is shown, wherein Figure 12a The schematic diagram is shown in cross-section. A hollow column 126 is formed in the support carriage 65, in which the actuator 124 is movable in a piston-like manner. To actuate the actuator 124, fluid, such as air or oil, can be supplied to the hollow column 126 on one side of the piston-like design of the actuator 124. Furthermore, a vacuum can be generated in the hollow column 124.

[0133] If the workpiece 14 is to be supported by two workpiece holders 12 and 78, the workpiece 14 is first coupled to the first support device 12. During this process, the second guide carriage 38 can be displaced along the workpiece carriage direction X1. Then, the workpiece 14 is coupled to the second support device 78 by actuating the actuator 124. Depending on the workpiece length of the workpiece 14 and the position of the second guide carriage 38 relative to the second carriage guide 39 along the workpiece carriage direction X1, the second workpiece holder 78 can also be located between the support carriage 65 and the stop 122. When the workpiece 14 is inserted, the movement of the second workpiece holder 78 along the workpiece holder carriage direction X3 depends on the movement of the second guide carriage 38 along the workpiece carriage direction X1.

[0134] Figure 13a A simplified detailed diagram of the device 10 according to the invention is shown, wherein the combination Figure 13b The relationship between the movement path and the carriage is shown. Workpiece 14 has a machining length dx1. To machine this length, for example by means of a first grinding tool 22, the first machining holder 12 is displaced by the same amount dx1 along the workpiece carriage direction X1. Furthermore, the support carriage 65 is displaced by a distance dx2 and the workpiece holder carriage 121 is displaced by a distance dx3. Therefore, as a formula, the relationship dx1 = machining length = dx2 + dx3 is obtained.

[0135] Figure 13b A simplified detailed diagram of the device 10 according to the invention is shown, wherein compared to Figure 13aThe first workpiece holder 12 has moved by a machining length dx1, the support carriage 65 has moved by a distance dx2, and the workpiece holder carriage 121 has moved by a distance dx3 relative to the support carriage 65 due to its coupling with the first workpiece holder 12 via the workpiece 14. The workpiece holder carriage 121 has also been spatially displaced by a machining length dx1 relative to the frame 66.

[0136] Figure 14a and Figure 14b A simplified detailed diagram of the device 10 according to the invention is shown, but in which the second grinding step is performed by means of an alternative process, which may also be referred to as on-the-fly processing (der fliegendenBearbeitung). Figure 14a This illustrates the start of the second grinding step. Unlike the previous description, the first grinding tool 22 and the second grinding tool 27 are as follows: Figure 14a As can be seen, the second grinding step begins away from the support device 69 and also away from the support 68 and the clamping roller 72. In other words, the second grinding step of this workpiece 14 also begins at the second workpiece end 84 and extends in the direction of the first workpiece end 82, but the support device 69 is not arranged near the second workpiece end 84, but rather near the first workpiece end 82 or near the area where the workpiece 14 is received in the first workpiece holder 12.

[0137] Combination Figure 14a and Figure 14b It is clear that the position of the support device 69 relative to the workpiece 14 and relative to the first workpiece holder 12 does not change during the instantaneous machining process in the second grinding step. Instead, the first workpiece holder 12 moves synchronously, i.e., to the same extent and simultaneously, in the direction of the grinding tools 22 and 26 along the X1 direction and the support carriage 65 moves along the X2 direction to process the workpiece 14 along the machining length dx1. As a result, the distance between the support device 69 and the grinding tools 22 and 26 is variable during instantaneous machining, while this distance remains substantially constant during the aforementioned second grinding step.

[0138] In the case of on-the-spot machining, the workpiece 14 is also rotated during the second grinding step. To also create a non-rotationally symmetric geometry on the workpiece 14, it can be specified that the oscillating motion of tools 22 and 26 along tool axes Y1 and Y2 is performed synchronously with the rotational motion of the workpiece 14. The rotational speed of the workpiece 14 is preferably not constant, but it can also be constant. It can also be specified that the second grinding step is performed multiple times. One advantage of on-the-spot machining becomes apparent here, especially in cases where the workpiece profile is asymmetrical, the movement of the support device 69 along the workpiece 14 may be problematic in some situations due to the different workpiece profiles: the support device 69 is arranged in an area of ​​the workpiece 14 that was not machined in the second grinding step. Of course, it must be considered that this supporting effect is reduced due to the large distance between tools 22 and 26 and the support device 69. Therefore, preferably, during on-the-spot machining, the distance between tools 22 and 26 or their engagement area with the workpiece 14 and the support device 69 or its engagement area is in the range of 0.5 to 100 mm.

Claims

1. A method for grinding an elongated workpiece (14), the method comprising the following steps: - Clamp the workpiece (14), wherein the workpiece (14) is supported in the first workpiece holder (12) at the first workpiece end (82) by means of the first centering device (44) and in the second workpiece holder (78) at the second workpiece end (84) by means of the second centering device (80); - A first grinding step is performed on at least a first section of the side surface of the workpiece (14) by means of a tool assembly (18); - Change the clamping of the workpiece (14), wherein the workpiece (14) is disengaged from the first centering device (44) and the second centering device (80), and one of the workpiece ends (82, 84) is received in the first workpiece holder (12); and - A second grinding step is performed on a second section of the side surface of the workpiece (14) by means of the tool assembly (18), wherein the support device (69) supports the workpiece (14) on at least a portion of the side surface of the workpiece (14), wherein the second section is arranged within or corresponds to the first section.

2. The method according to claim 1, wherein, During clamping, the workpiece (14) is coupled to the first centering device (44) via the axial end face of the workpiece (14) and / or the centering portion in the axial end face of the workpiece (14) and / or the inclined surface adjacent to the axial end face of the workpiece (14), and / or the workpiece (14) is coupled to the second centering device (80) via another axial end face and / or another centering portion in another axial end face of the workpiece (14) and / or another inclined surface adjacent to another axial end face of the workpiece (14).

3. The method according to claim 1 or 2, wherein, The workpiece (14) is ground into a rotationally symmetrical shape in the first section at least in the first grinding step; and / or wherein the first section includes the entire side surface of the workpiece (14).

4. The method according to claim 1 or 2, wherein, During the change clamping process, the workpiece (14) is supported on the side surface of the workpiece (14) by means of the support device (69) before and / or during disengagement; and / or The device includes a gripper (42) for holding the first centering device (44), which holds the first centering device (44) during a change clamping process and removes the first centering device (44) from the area between the first workpiece holder (12) and the first workpiece end (82); and / or The tool assembly (18) engages with the workpiece (14) offset relative to the engagement area of ​​the support device (69) in the direction of the workpiece longitudinal axis (W).

5. The method according to claim 1 or 2, wherein, During the transition clamping, the workpiece (14) is clamped on the side surface of the workpiece (14) by means of the support device (69) before and / or during disengagement; and / or During the second grinding step, the tool assembly (18) engages with the workpiece (14) offset from the engagement area of ​​the support device (69) in the direction of the workpiece longitudinal axis (W) of the workpiece (14), on the side of the support device (69) away from the first workpiece holder (12).

6. The method according to claim 1 or 2, wherein, During the first grinding step and / or the second grinding step, the workpiece (14) is moved relative to the support device (69) along the direction of the workpiece longitudinal axis (W) of the workpiece (14); and / or During the second grinding step, the support device (69) and the tool assembly (18) are spaced apart from each other at a constant distance.

7. The method according to claim 1 or 2, wherein, At least during the second grinding step, the support device (69) is arranged at a fixed position on the workpiece (14) relative to the longitudinal axis (W) of the workpiece. During the second grinding step, the distance between the support device (69) and the tool assembly (18) changes.

8. The method according to claim 1 or 2, wherein, During the second grinding step, the distance between the support device (69) and the tool assembly (18) is reduced.

9. The method according to claim 1 or 2, wherein, During the second grinding step, the tool assembly (18) is oriented at least partially different from the first grinding step.

10. The method according to claim 1 or 2, wherein, In the second grinding process, the first workpiece side surface (98) is ground to the first workpiece diameter, and the second workpiece side surface (100) is ground to the second workpiece diameter, wherein the first diameter is smaller than the second diameter.

11. The method according to claim 10, wherein, The second workpiece side surface (100) is arranged closer to the first workpiece holder (12) than the first workpiece side surface (98).

12. The method according to claim 1 or 2, wherein, At least one of the two workpiece holders (12, 78) includes a rotatably driven workpiece spindle (16), and the workpiece (14) is rotatably driven by the rotatably driven workpiece spindle (16) at least during the first grinding step and the second grinding step.

13. The method according to claim 12, wherein, The first workpiece holder (12) includes the workpiece spindle (16) which is rotatably driven.

14. The method according to claim 1 or 2, wherein, Measure at least one workpiece diameter in the first section after the first grinding step and / or measure at least one workpiece diameter in the second section after the second grinding step.

15. The method according to claim 1 or 2, wherein, Measure the length of the workpiece after changing the clamping position.

16. The method according to claim 1 or 2, wherein, After the clamping is changed, measure the position of the first workpiece end (82) or the second workpiece end (84).

17. An apparatus (10) for grinding an elongated workpiece (14), the apparatus (10) being configured to perform the method according to any one of claims 1 to 16, the apparatus (10) comprising: - A first workpiece retainer (12) for supporting the workpiece (14) via a first workpiece end (82) and a second workpiece retainer (78) for supporting the workpiece (14) via a second workpiece end (84). - Tool assembly (18) for grinding the workpiece (14); and - A support device (69) for supporting the workpiece (14) at least in stages on at least a portion of the side surface of the workpiece (14). The first workpiece holder (12) includes a rotatably driven workpiece spindle (16), wherein the rotatably driven workpiece spindle (16) is configured to at least partially receive the side surface of the workpiece (14).

18. The device (10) according to claim 17, wherein, The support device (69) is arranged on a support carriage (65), which is designed to be movable relative to the tool assembly (18) and relative to the first workpiece holder (12) in the direction of the workpiece longitudinal axis (W).

19. The device (10) according to claim 17 or 18, wherein, The tool assembly (18) includes a first grinding tool (22) and a second grinding tool (26), wherein the first grinding tool (22) is arranged on a first tool carriage (48) and the second grinding tool (26) is arranged on a second tool carriage (50) so that the grinding tools (22, 26) can move in a translational direction perpendicular to the longitudinal axis (W) of the workpiece (14) and / or perpendicular to the height direction (Z1); The first tool carriage (48) and / or the second tool carriage (50) are also arranged on a rotary device (49) for rotating the grinding tools (22, 26) about the tool carriage rotation axis (C1), wherein the tool carriage rotation axis (C1) is oriented in the height direction (Z1).

20. The device (10) according to claim 17 or 18, wherein, The apparatus (10) for grinding includes: a guide carriage (38) on which a first workpiece holder (12) is disposed; and a workpiece holder carriage (121) on which a second workpiece holder (78) is disposed, wherein the guide carriage (38) is movable along the workpiece carriage direction (X1) and the workpiece holder carriage (121) is movable along the workpiece holder carriage direction (X3).

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