A spindle system with an integrated guide element in the clamping portion of the tool holder.

Abstract

The present invention provides a spindle device that allows for the release connection of a tool holder equipped with a clamp capable of withstanding extremely high mechanical loads. [Solution] The spindle system comprises a spindle device having a work spindle to which a housing and a tool holder 400 can be releasably connected, a tool holder 400 having a clamp portion, a gripper portion 403, a tool receiving portion and a vibration transducer coupled thereto, and an energy transmission device having a first induction element and a second induction element 104b, wherein when the tool holder 400 is connected to the work spindle, the first induction element and the second induction element 104b face each other radially, and the second induction element 104b is formed integrally with the clamp portion 402 of the tool holder so that an automatic exchange device can engage with the gripper portion of the tool holder 400.

Description

Technical Field

[0001] The present invention relates to a spindle system, and more particularly, to a spindle system for ultrasonic machining of a workpiece, which uses a tool connected to a work spindle that is rotationally driven via an exchangeable tool holder, and energy is transmitted to the tool holder in a non-contact manner.

Background Art

[0002] Spindle systems for ultrasonic machining of workpieces using rotary tools are already known as prior art. Such systems typically have a vibration transducer connected to the tool receiving portion of the tool holder to transmit vibrations to the tool received in the tool holder.

[0003] For this purpose, for example, a piezoelectric element-based vibration transducer using a piezoelectric element as an actuator for generating vibrations is used. These piezoelectric elements are generally made of piezoelectric ceramics and are usually used as laminates. To generate vibrations, a voltage is applied to such a laminate. As a result, due to the inverse piezoelectric effect, the laminate of the piezoelectric element is deformed.

[0004] In order to effectively transmit vibrations to the tool, it is often necessary to consider a specific geometric relationship between the position of the vibration transducer and the position of the tool holder, so the vibration transducer is often directly installed on the tool holder.

[0005] In this configuration, there is a problem that it is necessary to establish an electrical connection between the rotating spindle (including the tool holder connected thereto) and the vibration transducer installed in the tool holder, and between the stationary housing (or the housing of the machine) around the spindle.

[0006] In this regard, for example, Patent Document EP3616830A1 discloses a configuration in which electrical energy is inductively transmitted from a coil in the spindle housing to a coil connected to the spindle shaft and rotating together with the spindle shaft. The electrical energy of the rotating coil on the spindle shaft is transmitted to a vibration transducer in the tool holder by a spring biasing pin on the tool holder side, which contacts the corresponding connection surface when the tool holder is connected to the spindle. [Overview of the project] [Problems that the invention aims to solve]

[0007] However, this method has several drawbacks. To ensure electrical conductivity, the spring biasing pin on the tool holder side and the contact surface on the spindle shaft side must always be kept clean. However, the contact surface and spring biasing pin are located in the connection area between the tool holder and the spindle shaft, and therefore come into direct contact with lubricants, for example. Furthermore, this connection area is located very close to the machining area, which is particularly susceptible to contamination, for example, by the use of coolant. Therefore, maintaining the cleanliness of the electrical connections requires considerable additional effort. In the worst case, contamination may only be detected during workpiece machining when the surface machining does not proceed as planned.

[0008] Another alternative, known as prior art, attempts to solve these problems by directly attaching the coil to the tool holder. The coil is typically positioned above the area in the tool holder where the tool is received. In this case as well, the electrical connection is established by a second coil inductively coupled to the coil on the tool holder side. Such a configuration restricts the shape of the stationary coil in order to allow the tool holder to be replaced via the tool receiving area, despite the presence of a coil in the tool holder. In particular, it is not possible to use a coil that is radially opposed to the rotating coil of the tool holder over its entire circumference.

[0009] Instead, the stationary coil is positioned so as to be radially opposite the rotating coil of the tool holder only over a portion of the circumference, such as half a turn or one-third of a turn. This allows the tool holder to be automatically separated from the spindle regardless of the position of the rotating coil on the tool holder (above the tool receiving area). However, limiting the range of the stationary coil to a portion of the circumference results in a significant reduction in the efficiency of electrical energy transfer to the rotating coil of the tool holder.

[0010] In short, the prior art solutions for transferring electrical energy from a stationary machine to a rotating tool holder have problems in terms of maintenance efficiency, connection reliability, and connection efficiency.

[0011] The objective of the present invention is to provide a spindle system that avoids the above-mentioned problems.

[0012] A further object of the present invention is to provide a tool holder equipped with a clamp capable of withstanding extremely high mechanical loads, and to enable a non-contact electrical energy transfer from the static environment of the spindle (to which the tool holder is connected) to the rotating tool holder that is more efficient and reliable than the prior art.

[0013] A further object of the present invention is to provide a machine tool that processes a workpiece using vibrations in the ultrasonic range, wherein the electrical energy required to generate ultrasonic vibrations is transmitted from a stationary machine part to a rotating tool holder more efficiently, reliably, and non-contact than in the prior art. Furthermore, the tool holder connected to the workpiece spindle of the machine tool needs to be replaceable by an automatic tool changer. [Means for solving the problem]

[0014] To achieve these objectives, a spindle system according to claim 1, a tool holder according to claim 4, a spindle device according to claim 9, and a machine tool according to claim 10 are provided.

[0015] Each dependent claim relates to a preferred embodiment that can be provided individually or in combination.

[0016] According to a first aspect of the invention, a spindle system for use in a machine tool is provided, the spindle system comprising at least a spindle device, a tool holder and an energy transfer device.

[0017] The spindle device comprises a rotary-driven work spindle having a receiving portion for releasably connecting a tool holder, and a spindle housing that supports the work spindle.

[0018] A releaseable connection is one that can be non-destructively undone again. In particular, connections using safety connections such as screw fasteners, clamps, fasteners, or bayonet closures are understood as releaseable connections.

[0019] Furthermore, the tool holder includes at least a clamp portion that is releasably connected to the work spindle of the spindle device, a gripper portion positioned below the clamp portion relative to the clamp end of the tool holder, a tool receiving portion, and a vibrating transducer coupled to the tool receiving portion and configured to vibrate the machining tool received in the tool receiving portion.

[0020] The clamp end of a tool holder refers to the axial end of the tool holder that connects to the work spindle, while the opposite axial end is called the tool-side end. In particular, the clamp portion is located at the clamp end of the tool holder, and the tool holder is configured to connect to the work spindle only by this clamp portion; therefore, the clamp end clearly indicates the axial side of the tool holder. Accordingly, being positioned below the clamp portion relative to the clamp end means that, in the axial direction from the clamp end to the tool-side end, the clamp portion is positioned first, followed by the gripper portion. Therefore, when the tool holder is connected to the work spindle and the tool holder is in a vertical position, the gripper portion will have its tool-side end facing downwards, i.e., it will be positioned below the clamp portion.

[0021] Furthermore, the energy transfer device includes a first inductive element and a second inductive element. The energy transfer device is configured to transfer energy non-contact between the first inductive element and the second inductive element radially opposite to the first inductive element in order to supply energy to the vibration transducer when the tool holder is connected to the work spindle. In particular, each of these elements may be a coil and configured to be inductively coupled to enable non-contact electrical energy transfer. Particularly advantageous, the two inductive elements are arranged to face each other radially when the tool holder is connected to the work spindle.

[0022] In this example, the first guide element is located in the spindle housing. This guide element may be advantageously configured as a stationary guide element, i.e., fixed in position relative to the rotationally driven workpiece spindle. The first guide element may be advantageously arranged in a ring on the spindle housing so that the axis of the workpiece spindle passes through the center of the guide element. Particularly advantageously, the first guide element is incorporated into the spindle housing and positioned so that the shape of the guide element fits entirely within the shape of the spindle housing.

[0023] The second guide element is positioned on the clamp portion of the tool holder. Advantageously, the second guide element is arranged in a ring on the clamp portion of the tool holder so that the central axis of the tool holder passes through the center of the guide element. In particular, when the tool holder is connected to a workpiece spindle, the axis of the workpiece spindle passes through the center of the second guide element.

[0024] Therefore, particularly advantageously, the first and second guide elements are arranged in a ring shape, and when the tool holder is connected to the work spindle, the axis of rotation of the rotary-driven work spindle passes through the center of both guide elements.

[0025] Furthermore, the guiding elements are oriented so as to face each other radially when the tool holder is connected to the work spindle. In particular, the first guiding element and the second guiding element are arranged so as to extend orthogonally to the axis of rotation of the rotationally driven work spindle. In this case, it is particularly advantageous for the first and second guiding elements to be concentrically oriented. According to this orientation, the two guiding elements arranged in an annular shape are at the same distance from each other over the entire circumference, ensuring a high transmission efficiency.

[0026] The inductive coupling of the guiding elements that face each other radially when the tool holder is connected to the work spindle results in improved transmission reliability compared to a configuration where the guiding elements face each other axially in the event of an incorrect orientation of the tool holder connected to the work spindle. In particular, an incorrect positioning where the tool holder is not properly clamped and as a result is connected too deeply to the work spindle is considered here. That is, the tool holder is incorrectly connected to the work spindle, for example, in a state where the receiving part of the work spindle does not fully fit into the clamping part of the tool holder. When observing the tool holder arranged downward along the axis of rotation of the work spindle, the tool holder is in a state of being seated too deeply with respect to the work spindle.

[0027] When the guiding elements are axially oriented, such an incorrect orientation increases the distance between the guiding elements and has a significant adverse effect on the transmission efficiency.

[0028] In contrast, when the guiding elements are oriented radially with respect to each other, the distance between the guiding elements is mainly determined substantially by the arrangement of the guiding elements on the tool holder and the spindle housing. In this case, an incorrect orientation along the axis of rotation of the tool holder mainly leads to the guiding element on the tool holder side being located slightly deeper, but the influence on the transmission efficiency is much smaller compared to the change in the distance between the guiding elements.

[0029] According to a first aspect of the invention, the second induction element is formed integrally with the clamping part of the tool holder such that an automatic changer can be engaged with the gripper part of the tool holder.

[0030] This integral formation with the clamping part of the tool holder is advantageous for a plurality of reasons compared to prior art solutions.

[0031] First, since it can engage with the gripper part of the tool holder as usual, existing automation devices can continue to be used. Even if the tool holder has an additional function as an induction element that supplies energy to the vibration transducer, the gripper part is not obstructed. The fact that the tool holder is suitable for ultrasonic processing by the induction element and the vibration transducer is so-called transparent (influenceless) to the automation device based on the engagement with the gripper part. Therefore, an automation device can be provided regardless of the presence or absence of ultrasonic processing, improving the flexibility of use of the corresponding device and thus the economy.

[0032] Second, by forming the second induction element integrally with the clamping part of the tool holder, the arrangement of the first induction element that transmits electrical energy to the second induction element in a non-contact manner becomes particularly suitable. The first induction element can be arranged within the spindle housing in the vicinity of the region where the tool holder is connected to the work spindle, but does not protrude into the processing region. This avoids an inconvenient interference profile in the processing region, prevents a decrease in processing flexibility, and also avoids problems related to additional automation devices.

[0033] The first induction element is particularly preferably configured as a coil that completely surrounds the region where the tool holder is connected to the work spindle and the region where the second induction element is arranged over the entire 360° circumference when the tool holder is connected to the work spindle. Thereby, compared to the prior art in which the first induction element is arranged only in a part of the circumferential direction of the second induction element, the electrical energy transmission efficiency to the second induction element is particularly advantageously improved.

[0034] In a particularly advantageous embodiment, the clamp portion of the tool holder is formed as a hollow shank taper. In particular, the clamp portion may be formed as a standardized hollow shank taper (HSK). Particularly advantageous, the second guide element is formed integrally with the standardized hollow shank taper, and in particular, the clamp portion into which the guide element is integrally formed is provided to satisfy all the standard requirements of the HSK.

[0035] This embodiment is particularly advantageous. This is because, according to the HSK standard, it has a flat contact surface positioned above the gripper portion when the tool is positioned downwards. In a tool holder connected to the spindle shaft, this flat contact surface receives more than 80% of the total clamping force, which decisively contributes to the limit load and rigidity of the connection between the spindle shaft and the tool holder. Furthermore, since this flat contact surface is not penetrated by contact pins or the like, or because a flat contact surface conforming to the HSK standard can be formed by integrally forming the clamp portion of the guide element, higher limit load and rigidity are achieved in the connection between the spindle shaft and the tool holder. Therefore, in this embodiment, compared to a configuration in which, for example, contact pins or the like penetrate the flat contact surface, machining requiring greater force becomes possible.

[0036] In another advantageous embodiment, the clamping portion of the tool holder is formed as a steep taper. This embodiment simplifies tool or tool holder replacement and is particularly advantageous in highly automated workpiece machining using a large number of different tools. Furthermore, the steep taper allows for a reduced distance between the cutting edge of the tool received in the tool holder and the spindle bearing of the workpiece spindle to which the tool holder is connected, thereby achieving high bending rigidity.

[0037] In a particularly advantageous embodiment, the tool holder further comprises wiring that is connected to the vibration transducer without soldering in order to transmit electrical energy from the inductive element of the tool holder to the vibration transducer.

[0038] This embodiment is particularly advantageous when using a vibration transducer based on a piezoelectric laminate. In these piezoelectric laminates, electrodes for exciting the piezoelectric elements are typically soldered using a solderable material. Since many piezoelectric laminates are very compact, these connections are made directly on the sides of the piezoelectric laminate, which can result in the formation of large, protruding solder points on the longitudinal sides of the piezoelectric laminate. These large solder points reduce the possibility of miniaturization because they require corresponding space within the tool holder, and they also significantly reduce manufacturing efficiency because soldering is a manual process.

[0039] Therefore, solderless connections reduce the space requirements, particularly for vibration transducers, and consequently, the minimum required size of the tool holder. The combination of the clamp section and the second induction element integrated into the tool holder eliminates the need for dimensional changes, even for tool holders configured for ultrasonic machining. This eliminates the need for additional modifications to automated equipment such as tool changers and magazines.

[0040] Furthermore, this advantageous embodiment of the tool holder eliminates the need for manual soldering, thus significantly improving manufacturing efficiency.

[0041] According to a second aspect of the invention, a tool holder for a spindle system is provided, comprising: a clamp portion for releasably connecting to a work spindle of a spindle device; a gripper portion positioned below the clamp portion relative to the clamp end of the tool holder; a tool receiving portion; and a vibrating transducer coupled to the tool receiving portion and configured to vibrate a machining tool received in the tool receiving portion. The tool holder has an induction element in the clamp portion, which is configured to receive non-contact electrical energy when the tool holder is connected to the work spindle and to transmit it to the vibrating transducer. The induction element is formed integrally with the clamp portion of the tool holder so that an automatic changer can engage with the gripper portion of the tool holder.

[0042] Since the induction element is integrally formed with the tool holder, the tool holder can be used for ultrasonic machining of the workpiece as needed. The induction element, integrally formed with the clamp, can receive electrical energy from other induction elements non-contact and transmit it to the vibration transducer coupled to the tool receiving section. This allows the vibration transducer to vibrate the tool receiving section, and consequently, the tool received in the tool receiving section.

[0043] On the other hand, the tool holder can be used even when ultrasonic machining is not required, or when ultrasonic machining is not supported in a machine that does not have, for example, an induction element for electrical energy transmission. This is because the induction element is formed integrally with the clamp portion of the tool holder, thus avoiding interference in the machining area that may occur if, for example, the induction element is additionally attached to the outside of the tool holder. As a result, the flexibility of using the tool holder is increased, and consequently, the cost-effectiveness is improved compared to a tool holder fixed to one of the machining methods.

[0044] In a particularly advantageous embodiment of the tool holder, its clamping portion is formed as a hollow shank taper. The advantages of this have already been described above.

[0045] In another advantageous embodiment of the tool holder, the tool holder is formed with a steep taper. The advantages of this aspect have already been described.

[0046] Particularly advantageous is that the tool holder further has wiring that is solderless-free connected to the vibration transducer in order to transfer electrical energy from the inductive element to the vibration transducer. The advantages of the solderless connection between the inductive element and the vibration transducer have already been explained.

[0047] Furthermore, it is particularly advantageous that the connecting portion, which includes at least the clamp and gripper portions of the tool holder, is manufactured from at least two parts. The two-part configuration makes it particularly easy to form the guide element integrally with the clamp portion. For example, two different parts can be manufactured in advance: a first part that substantially forms the clamp portion, one of which primarily forms the clamp portion and has a notch for fitting the guide element; and a second part that substantially has a connection to the gripper portion and the rest of the tool holder, which may be formed to precisely fit with the first part forming the clamp portion, thereby surrounding the guide element within the notch of the clamp portion. The two precisely joined parts thus form the connecting portion of the tool holder and also surround the guide element. Pre-manufacturing the individual parts constituting the connecting portion of the tool holder facilitates the assembly and integration of the guide element. In particular, these two individual components may be connected to each other by press-fitting, bonding, welding, or other non-destructive methods, or by a detachable or non-detachable method, in any case surrounding the guide element of the tool holder.

[0048] Furthermore, one or both of the components forming the connection may be provided with holes, such as bores, which allow wiring to be passed through for connecting the induction element to, for example, a vibration transducer of a tool holder.

[0049] In another advantageous embodiment, a circumferential groove is provided in the clamp portion of the tool holder, and a guide element is at least partially embedded in the groove. According to this embodiment, the tool holder can be manufactured as a single unit, further reducing the complexity of manufacturing. For this purpose, the tool holder is manufactured by a well-known method, and then a groove is formed in the clamp portion. In particular, this groove may be formed by milling or turning. Subsequently, the guide element of the tool holder is at least partially embedded in the groove. In particular, the guide element may be formed as a coil that is wound directly in the groove of the clamp portion. Alternatively, a ferrite element having a U-shaped cross-section may be first inserted into the groove, and then a coil may be wound around the ferrite element placed in the groove.

[0050] Advantageously, the guide element is positioned in the clamp portion of the tool holder, or the clamp portion is formed such that the outer diameter of the clamp portion in the region where the guide element is positioned is equal to the outer diameter of the clamp portion in the region where the guide element is not positioned.

[0051] For example, if the connection portion of a tool holder is formed with two parts, the part forming the clamp portion may be manufactured with a constant outer diameter. In particular, the outer diameter does not change in the region where a notch for receiving the guide element is provided. This allows the guide element to be formed integrally with the clamp portion without changing the outer diameter of the clamp portion.

[0052] Furthermore, if the outer diameter is formed according to the corresponding standard, the clamp portion will be standard compliant, differing only in that the corresponding tool holder incorporates a guide element to accommodate ultrasonic machining. This compatibility with ultrasonic machining is transparent to automated devices such as automatic tool changers and / or tool magazines; that is, no special precautions are required for such devices to automatically change and / or store such tool holders, and when such manufactured tool holders are used, the machine used for ultrasonic machining does not require a separate automated system.

[0053] Similarly, in a tool holder having a groove in the clamp portion, if the guide element of the tool holder is embedded in the groove or wound around the groove and formed to match the outer diameter of the clamp portion, it can be constructed without causing a change in the outer diameter of the clamp portion. In particular, the guide element is formed to completely fill the groove and not protrude outside the groove.

[0054] Furthermore, the clamp portion, which is formed integrally with the guide element, is advantageously constructed such that the relative change in the outer diameter of the clamp region along the axial direction of the tool holder in the region where the guide element is positioned is equal to the relative change in the axial outer diameter in the region where the guide element is not positioned. In particular, both relative outer diameter changes are defined in the same axial direction of the tool holder.

[0055] For example, the outer diameter of the clamp portion of a tool holder may increase continuously from the clamp end toward the gripper portion. This occurs when the clamp portion is formed as an HSK or steep taper. In this case, the outer diameter of the clamp portion changes according to the definition or standard of the corresponding taper. In particular, the region in which the guide element is formed integrally with the clamp portion does not differ from the surrounding region of the clamp portion in terms of the change in outer diameter.

[0056] Particularly advantageous is that the clamping portion is formed integrally with the guide element so as to satisfy all standard requirements such as HSK standards or steep taper standards with respect to dimensions, especially changes in outer diameter. Relevant standards include, for example, ISO 12164 (DIN 69893-1) and ISO 7388-1.

[0057] This advantageous embodiment allows the tool holder to be used with all machine tools equipped with a standards-compliant interface, improving flexibility of use.

[0058] According to another aspect of the invention, a spindle device for use in a spindle system is provided. The spindle device comprises at least a rotary-driven work spindle having a receiving portion for a tool holder, a spindle housing supporting the work spindle, and an induction element disposed in the spindle housing, wherein the induction element is configured to non-contactively transmit electrical energy to the induction element of the tool holder when the tool holder is connected to the work spindle.

[0059] In this case, the guide element positioned in the spindle housing is advantageously positioned to be radially opposed to the guide element formed integrally with the clamp portion of the tool holder when the tool holder is connected to the workpiece spindle.

[0060] In a particularly advantageous embodiment, the guide element located in the spindle housing is configured in an annular shape and oriented perpendicular to the principal extending direction of the work spindle, so that the work spindle passes through the center of the annular guide element. In particular, the guide element advantageously extends over the entire 360° of the radial circumference of the work spindle. This advantageous embodiment significantly improves transmission efficiency compared to guide modules that extend only in a portion of the circumferential direction (e.g., only 90° or 120°).

[0061] Particularly advantageous is that the guide element positioned in the spindle housing is mounted to be movable in a direction perpendicular to the main extending direction of the work spindle. This further improves flexibility of use. For example, in a tool holder with a relatively long clamp portion, the guide element formed integrally with the clamp portion may be located deeper relative to the work spindle. In this case, by displacing the guide element on the spindle housing side downward toward the receiving portion, an orientation radially opposed to the guide element of the tool holder with a relatively long clamp portion can be achieved. On the other hand, when a tool holder with a relatively short clamp portion is used, the guide element of the spindle housing may be displaced in the opposite direction to allow for radially opposed orientation of the guide element located higher relative to the work spindle.

[0062] According to a further aspect of the invention, a machine tool is provided that is configured for ultrasonic machining of a workpiece, comprising one of the spindle systems already described. The spindle system provided therein makes the machine tool particularly efficient and effective for achieving ultrasonic machining. In particular, it can be used in a highly automated environment because it can be seamlessly combined with automation devices such as tool changers and / or magazines. A notable advantage is that ultrasonic machining is possible without requiring any modifications to the automation devices. This is made possible, in particular, by tool holders configured to be suitable for ultrasonic machining by guide elements integrally formed with the tool receiving and clamping portions. These can be clamped in the same way as conventional tool holders. They can also be handled by the automation devices in the manner of gripping, moving, positioning, storing, removing and / or other ways. The high degree of automation thus achievable has a particularly positive impact on downtime, and as a result, the presented machine can be operated very economically.

[0063] According to a further aspect of the invention, a milling tool, grinding tool, or drilling tool is received in the tool receiving portion of the tool holder of the spindle system of a machine tool for ultrasonic machining. In this way, depending on the received tool, the machine can be used for the respective machining operations, namely milling, grinding, or drilling. Here, each tool is vibrated by a vibratory transducer to achieve ultrasonic machining of the workpiece surface. As a result, the flexibility of the machine tool is further increased.

[0064] In a more advantageous embodiment, the tool receiving portion of the tool holder of the spindle system of a machine tool for ultrasonic machining accepts tools having geometrically defined or geometrically undefined cutting edges. This embodiment allows for further adaptation of the machining process to a desired machining scenario. [Brief explanation of the drawing]

[0065] [Figure 1] A cross-sectional view of the spindle system 100 into which the tool holder 400 is received is shown. [Figure 2a] This shows the coil arrangement in the radial direction. [Figure 2b] This shows the coil arrangement in the axial direction. [Figure 3] This shows a cross-sectional view of the tool receiving portion of a tool holder 300, which includes a tool receiving portion 404 and a coupled vibration transducer 405. [Figure 4a] This shows an exploded view of the tool holder 400. [Figure 4b] Figure 4a shows the assembled tool holder 400.

[0066] Figure 1 shows a cross-sectional view of an advantageous embodiment of the spindle system 100 in which the tool holder 400 is received. The energy transfer device 103 is configured as a pair of annular coil-based induction elements 104a, 104b arranged radially opposite to each other. Advantageously, in this example, the stationary coil 104a is located within the spindle housing 102. Advantageously, the arrangement of the coil 104b, which rotates with the tool holder 400 within the clamp portion 401, is selected to obtain a favorable radial orientation when the tool holder 400 is connected to a workpiece spindle (not shown). The advantages of this radial orientation will be explained with reference to Figures 2a and 2b.

[0067] Furthermore, Figure 1 shows that the guide element of the tool holder 104b is positioned to sink into the groove 406 that encircles the tool holder. This is advantageous in several respects.

[0068] Firstly, the guide element 104b of the tool holder can be fitted very well to the outer diameter of the tool holder 400 by this method. This makes it possible to keep the distance between the two guide elements (see reference numeral 201 in Figure 2a) small, enabling high efficiency in the transfer of electrical energy between the guide elements.

[0069] Secondly, the diameter of the guide element 104b, which is configured as a coil, can be kept smaller compared to an element mounted on the outside of the tool holder 400 without a groove. This keeps the centrifugal force acting on the guide element 104b small during the rotation of the tool holder. As a result, the tool holder 400 in which the guide element 104b is inserted or embedded in the groove 406 can be rotated at a higher rotational speed, and therefore the surface quality of the workpiece machined by the tool used in such a tool holder 400 is improved.

[0070] In particular, as can be seen from the cross-sectional view in Figure 1, the gripper portion 403 of the tool holder 400 is exposed and is not covered or hidden, for example, by the spindle housing 102. Furthermore, in the embodiment shown in Figure 1, the gripper portion of the tool holder 403 has multiple engagement grooves. This allows for compatibility with a number of different automated devices. Automated devices such as grippers and tool changers can engage with the gripper portion 403 from below the spindle housing 102 in any direction. In particular, such engagement is possible axially from below the tool receiving portion 404 or radially.

[0071] The integral formation of the guide element 104b and the clamp portion of the tool holder 401 allows for a particularly favorable arrangement of the first guide element 104a, and as a result, efficient energy transfer can be achieved without reducing the possibility of automation related to tool changes, for example.

[0072] Figure 2a shows a cross-sectional view of a coil arrangement 200 consisting of two coils 202, each of which is housed within an element 203. This element 203 may be, for example, a groove 406 in the clamping area of ​​a tool holder 400. In an alternative embodiment, element 203 is a (partial) coating made of ferrite material. In such an embodiment, the guide elements 104a, 104b would include a (partial) coating made of ferrite material and coils wound therein. The guide element arrangements described herein should be understood independently of the specific configuration of the corresponding guide elements.

[0073] In particular, Figure 2a shows the radial coil arrangement, which is also realized in the embodiment of Figure 1. For clarity, both coils are shown identically. Note that the advantages of radial coil arrangement also arise in the case of coils with different configurations.

[0074] The distance 201 between the coils is particularly important for the efficiency of electrical energy transfer from one coil to the other. Here again, the advantage of radial arrangement is recognized, because, as can be seen from Figure 1, the distance 201 does not depend on the axial position of the coils, but rather on the diameters of the annular coil elements 104a and 104b. Therefore, even if axial displacement in direction V, i.e., displacement between the coils occurs due to manufacturing tolerances of the tool holder 400, for example, the distance 201 does not change in the case of radial arrangement. As a result, the transfer efficiency is affected to a very small extent.

[0075] In contrast, as is known from prior art and as shown in Figure 2b, when the coils 202 are arranged facing each other in the axial direction, it is understood that such misalignment directly affects the distance between coils 201. For example, if the tool holder 400 is mounted too deeply relative to the spindle, the distance between coils 201 increases, which directly negatively affects the efficiency of electrical energy transfer between the coils 202.

[0076] Figure 3 shows a cross-sectional view of an advantageous embodiment of the tool receiving device 300 of the tool holder 400. In the illustrated embodiment, the vibration transducer 405 of the tool holder 400 is configured as a laminate of piezoelectric elements. Particularly advantageous, the tool receiving device 300 is provided with wiring 301, which is connected to the vibration transducer 405 without the use of soldering. In particular, the connection between the wiring 301 that transmits electrical energy from the induction element 104b to the vibration transducer 405 and the vibration transducer 405 is established via a shape-fit 302. The advantages of such an embodiment have already been described above.

[0077] Figure 4a shows an exploded view of an advantageous embodiment of the tool holder 400, in which the connecting portion of the tool holder, including the clamp portion 401 and the gripper portion 403, is composed of two parts. This embodiment allows for particularly efficient manufacturing of the tool holder because the parts 401 and 403 can be manufactured independently before being assembled as the connecting portion of the tool holder 400. For example, a through hole 412 may be provided through which wiring 301 can pass to facilitate the assembly and integration of the induction element 104b, and the wiring 301 connects the induction element 104b to the vibration transducer 405.

[0078] This embodiment is further advantageous in that the clamp portion 401 has a hollow shank taper 411. Particularly advantageous in this embodiment is the flat contact surface 410, which absorbs most of the clamping force when the tool holder 400 is connected to the workpiece spindle, thereby improving the limit load and rigidity of the tapered-hollow shank connection.

[0079] Figure 4b shows the tool holder 400 after assembly as shown in Figure 4a.

[0080] Exemplary or exemplary embodiments of the present invention and their advantages have been described in detail above with reference to the accompanying drawings.

[0081] It should be emphasized again, however, that the present invention is not limited or restricted in any way to the embodiments and features of the embodiments described above. Rather, the present invention further includes modifications to the above embodiments, in particular modifications to the features of the described examples, or combinations of individual or multiple features of the described examples within the scope of protection of the independent claims. [Explanation of Symbols]

[0082] 100 Spindle System 102 Spindle Housing 103 Energy Transfer Device 104a (Stationary) Induction Element 104b (Rotation) Induction Element 200 coil arrangement 201 Coil spacing 202 coils 203 Elements surrounding the coil 300 Tool receiving device 301 Wiring 302 Connection by shape fitting 400 Tool Holder 401 Clamp section 402 Tool holder clamp end 403 Gripper section 404 Tool receiving section 405 Vibration Transducer 406 Groove formed in the clamp section 410 Flat contact surface 411 Hollow Shank Taper 412 Wiring holes 500 Spindle Device

Claims

1. A spindle system (100) for use in a machine tool, wherein at least, A spindle device (500) comprising a rotary-driven work spindle having a receiving portion to which a tool holder (400) is releasably connected, and a spindle housing (102) that supports the work spindle, A tool holder (400), which comprises at least, A clamp portion (401) for releasably connecting the spindle device (100) to the workpiece spindle, A gripper portion (403) is positioned below the clamp portion (401) relative to the clamp end (402) of the tool holder. Tool receiving portion (404), and A vibration transducer (405) is coupled to the tool receiving portion (404) and configured to vibrate the machining tool received in the tool receiving portion (404). A tool holder (400) having, An energy transfer device (103) having a first induction element (104a) and a second induction element (104b), Equipped with, The first induction element (104a) is positioned in the spindle housing (102), The second guide element (104b) is positioned in the tool holder (400) in the clamp portion (401), and When the tool holder (400) is connected to the workpiece spindle, the energy transfer device (103) is configured to transfer energy non-contact between the first induction element (104a) and the second induction element (104b) which is radially opposite to the first induction element, in order to supply energy to the vibration transducer (405). The second guide element (104b) is formed integrally with the clamp portion of the tool holder (400) so that the automatic exchange device can engage with the gripper portion (403) of the tool holder (400). Spindle system (100).

2. The clamp portion of the tool holder (400) is formed as a hollow shank taper (411). The spindle system (100) according to claim 1.

3. The clamp portion of the tool holder (400) is formed as a sharp taper. The spindle system (100) according to claim 1.

4. The tool holder (400) further includes wiring (301) that is connected to the vibration transducer (405) without soldering, in order to transmit electrical energy from the inductive element of the tool holder (104b) to the vibration transducer (405). A spindle system (100) according to any one of the preceding claims.

5. A clamp portion (401) that can be released onto the workpiece spindle of the spindle device (500), A gripper portion (403) is positioned below the clamp portion (401) relative to the clamp end (402) of the tool holder, Tool receiving portion (404) and A vibration transducer (405) is coupled to the tool receiving portion (404) and configured to vibrate the machining tool received in the tool receiving portion (404), It has at least the following features: The tool holder (400) is configured such that a guide element (104b) is positioned in the clamp portion (401), and when the tool holder (400) is connected to the workpiece spindle, it receives electrical energy in a non-contact manner and provides it to the vibration transducer (405). The guide element is formed integrally with the clamp portion of the tool holder (401) so that the automatic exchange device can engage with the gripper portion of the tool holder (403). A tool holder (400) for a spindle system (100) according to any one of the preceding claims.

6. The clamp portion (401) is formed as a hollow shank taper (411). The tool holder (400) according to claim 5.

7. The clamp portion (401) is formed as a steep taper. The tool holder (400) according to claim 5.

8. The inductive element (104b) further has wiring (301) that is connected to the vibration transducer (405) without soldering in order to transmit electrical energy from the inductive element (104b) to the vibration transducer (405). A tool holder (400) according to any one of claims 5 to 7.

9. The connecting portion of the tool holder, which includes at least the clamp portion (401) and the gripper portion (403), is manufactured from at least two parts. A tool holder (400) according to any one of claims 5 to 8.

10. The guide element of the tool holder (104b) is provided on the clamp portion of the tool holder (401) and is at least partially embedded in a groove (406) that encircles the tool holder. A tool holder (400) according to any one of claims 5 to 9.

11. The outer diameter of the clamp portion (401) of the tool holder (401) in the region where the guide element (104b) is placed is equal to or less than the outer diameter of the clamp portion (401) of the tool holder (401) in the region where the guide element (104b) is not placed. A tool holder (400) according to any one of claims 5 to 10.

12. The relative change in the outer diameter of the clamp portion (401) in the axial direction of the tool holder (400) in the region where the guide element (104b) is placed is equal to the relative change in the outer diameter of the clamp portion (401) of the tool holder (400) in the region where the guide element (104b) is not placed. A tool holder (400) according to any one of claims 5 to 10.

13. A rotary-driven work spindle having a receiving portion for a tool holder (400), The spindle housing (102) that supports the workpiece spindle, The guide element (104a) is arranged in the spindle housing (102), Equipped with, The induction element (104a) is configured to transmit electrical energy to the induction element of the tool holder (104b) in a non-contact manner when the tool holder (400) is connected to the work spindle. A spindle device (500) for a spindle system (100) according to any one of claims 1 to 4.

14. A machine tool comprising a spindle system (100) according to any one of claims 1 to 3, configured for ultrasonic machining of a workpiece.

15. A milling tool, grinding tool, or drill tool is received in the tool receiving portion of the tool holder (404) of the spindle system (100) for ultrasonic machining. The machine tool according to claim 10.

16. A tool having a geometrically defined cutting edge or a geometrically undefined cutting edge is received in the tool receiving portion of the tool holder (404) of the spindle system (100) for ultrasonic machining. The machine tool according to claim 10 or 11.

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