Tool holding device for turning applications and lathe equipped with such tool holding device

Abstract

Disclosed is a tool holding device (1) for a turning machine, the tool holding device comprising a housing (2) and a first vibrating mechanism (5), the first vibrating mechanism (5) being a tool holder (12) for holding a tool (28), the tool holder (12) comprising a vibrating bearing (26), the tool holder (12) comprising at least one elastic element (4) abutting the tool holder (12) at one end and the housing (2) at the other end, a motion link (8) connected to the housing (2) and used to movably embed the tool holder (12), and a pulse spindle (10) mounted on the housing (2) and abutting the vibrating bearing (26) of the tool holder (12) at its side surface (21), the side surface (21) being substantially cylindrical and interrupted by at least one protrusion (22). At least one elastic element (4) is positioned to press the tool holder (12) toward the side (21) of the pulse spindle (10) with the vibrating bearing (26) such that the rotation of the pulse spindle (10) generates vibrations in the tool holder (12) due to irregularities (22) on the side (21) of the pulse spindle (10). The pulse spindle (10) is displaceably mounted in the housing (2) so as to be displaceable along the longitudinal axis (a) of the pulse spindle (10), and at least one irregularity (22) is a surface (22) with an inclined shape when viewed along the longitudinal axis (a) of the pulse spindle (10), so that the contact point between the pulse spindle (10) and the vibrating bearing (26) is selectable along the longitudinal axis (a), and the amplitude of vibration is modifiable and adjustable.

Description

Technical Field

[0001] The present invention relates to the field of lathe machines, and more particularly, to a tool holding device generally for turning applications and more specifically for lathe machines.

Background Art

[0002] When manufacturing a workpiece using a lathe or a turning machine, typically, the blank is fixedly connected to the rotating spindle of the lathe. Material removal occurs when the tool is driven into the rotating blank to produce a final workpiece that includes a circumferential pattern or shape. Workpieces manufactured using a lathe are widely used in machine manufacturing, tool manufacturing, the medical implant industry, the vehicle industry, and the like. The tool is attached to a carriage that can move along the rotating spindle and the blank rotating therewith. Typically, the longitudinal direction defined by the rotating spindle of the lathe and the blank rotating therewith is parallel to the z-direction of the coordinate system. The x-direction of the coordinate system is perpendicular to the longitudinal axis defined by the rotating spindle. To generate an inclined shape, a rounded shape, or other circular symmetric shapes, the tool can be fed in any of the z-direction, the x-direction, or a combination thereof.

[0003] Blanks are made from machinable materials such as metal, wood, plastic, mineral, and stone. At least some of these materials, such as metal and plastic, can produce long chips or shavings that can cause problems. Such long flakes or chips / shavings can significantly hinder the turning process. Long chips or shavings can interfere with actual turning by damaging the cutting inserts of the workpiece and / or tool, resulting in workpiece or tool damage, and associated quality issues and / or maintenance downtime due to the need to replace the tool. Finally, such long chips or shavings are typically spiral in shape and tend to clump together, which can cause problems with coolant distribution, as coolant is sometimes used and the clumps or shavings can clog nozzles, etc., which direct the coolant toward the workpiece. Instead of clogging the nozzles, the clumps or shavings can also misdirect the spray, and therefore the coolant does not reach the workpiece or tool. When chips clump together, other clogging can occur.

[0004] Efforts have been made to provide vibration or oscillation to break down chips into smaller fragments and pieces. However, in the prior art, generating vibration usually requires moving the entire carriage or cross slide that holds the tool post or turret back and forth. However, because the carriage is relatively heavy, there are limitations to generating vibration, which leads to reduced machine efficiency and potential exposure to maintenance downtime. In addition, existing solutions for generating vibration typically attempt to move the entire carriage, which has a fairly large mass, such as the tool and frame, along the x or z direction. This introduces inertial forces, limiting the frequency and amplitude that can be generated, which limits the cutting speed and the resulting productivity. [Overview of the Initiative]

[0005] The objective of the present invention is to provide a reliable tool holding device for a lathe or turning machine that improves efficiency, reduces chip size, particularly chip length, and minimizes maintenance downtime.

[0006] In light of the above problems, the inventors of the present invention have found that a mechanical solution can be used to generate vibration using a pulse spindle, the pulse spindle comprising a side having at least one irregularity, at least one elastic element, thus a spring, a hydraulic or pneumatic cylinder, an elastomer, or any other suitable type of elastic element, and a tool holder preferably held in a unidirectional or unidirectional manner, which is movable but elastic, so that at least one elastic element presses the tool holder toward the side of the pulse spindle so that the irregularity generates vibration within the tool holder when the pulse spindle is rotating. The inventors have further found that it is possible to generate amplitude adjustment of the vibration so that the amplitude can be adjusted by displacing the pulse spindle along its longitudinal axis when the irregularity is formed on a conical or inclined surface. This adjustment may be performed manually or automatically via a control system using a servo motor or the like. The inventors have further found that it is possible to combine two vibration systems or mechanisms to provide vibration to a tool in two different directions. This means that the vibration direction of the turning tool can be adjusted to any cutting direction of the turning tool, which means that many surface shapes with very smooth surfaces, such as inclined surfaces, spherical surfaces, or combinations thereof, can be realized.

[0007] The specification discloses a tool holding device for a turning machine. The tool holding device comprises a housing and a first vibration mechanism. The first vibration mechanism is A tool holder for holding a tool, wherein the tool holder is equipped with a vibrating bearing, At least one elastic element that abuts against the tool holder at one end and against the housing at the other end, A motion link is connected to the housing and the tool holder, and is used to movably embed the tool holder. A pulse spindle embedded in the housing, The pulse spindle is substantially cylindrical and has a side interrupted by at least one irregularity. At least one elastic element is positioned to push the tool holder toward the side of the pulse spindle, such that the rotation of the pulse spindle causes vibration in the tool holder due to the irregularity on the side of the pulse spindle, by the vibrating bearing contacting the side.

[0008] Using the tool holding device for the turning machine described above, long chips and long shavings can be effectively broken into shorter and smaller fragments in a lathe. Generally, the irregularities can be shaped so that the amplitude can be adjusted by displacing the pulse spindle longitudinally. Furthermore, the sides of the pulse spindle may include several irregularities on the sides in order to generate higher frequency vibrations or pulses. One or more irregularities may protrude from the sides or be formed inward from the sides.

[0009] The pulse spindle can be displaced along its longitudinal axis, and thereby at least one of the protrusions is a machined surface that is conically inclined when viewed along the longitudinal axis of the pulse spindle. In this way, the contact point between the pulse spindle and the vibrating bearing can be selected along the longitudinal axis, and consequently, the amplitude of the vibration can be changed and adjusted.

[0010] The ability to adjust the amplitude is beneficial with respect to turning for the following reasons: Typically, the tool is fed, which is typically given by the feed rate per revolution, and therefore, for example, 0.5 mm of z movement per revolution of the turning spindle of a lathe, and thus the workpiece. This means that while the workpiece and, consequently, the turning spindle of the lathe, rotates once, the tool moves 0.5 mm in the feed direction. Accordingly, in order to break (long) chips into shorter pieces, the amplitude of one pulse needs to be at least 0.5 mm, preferably a little more. The pulse frequency and the resulting rotational speed of the pulsed spindle affect the length of the chip, and generally, the higher the frequency, the shorter the chip, but as those skilled in the art will understand, there are certain practical limits. Thus, embodiments of the present disclosure have great advantage because the amplitude can be adjusted according to the feed rate.

[0011] In addition, the length of the generated chips can be adjusted and controlled by changing the frequency. The frequency can be changed by providing two or more grooves / inclined surfaces around the perimeter of the side of the pulse spindle, or by increasing the rotational speed of the pulse spindle. From the above, it becomes even clearer that the cutting speed in meters per minute or the peripheral distance per unit of time on the workpiece affects the length of the chips or shavings. The faster the cutting speed, the longer the chips.

[0012] While pulse frequency and cutting speed affect chip length, the amplitude must be adjusted relative to the feed rate to cause chip fracture. The tool holding devices presented herein allow both pulse frequency and amplitude to be adjusted independently of each other.

[0013] A motion link may comprise one or more devices designed to steer and control the direction of vibration. Such devices may be embodied as laminated springs or membranes. Another embodiment of a motion link may be designed as a linear guide. Such a linear guide may comprise a guide rail oriented parallel to the movement that must move the body, and a thread or slider movably positioned on the guide rail. A motion link may be made of a resilient, elastic material, or may be designed as at least a mechanism that allows forward and backward movement in at least one direction. However, the primary purpose of a motion link is to steer and control the direction of vibration and movement.

[0014] One solution that has proven to work well is one or more membranes connecting the housing or frame to the tool holder, so that the plane defined by the membranes is oriented perpendicular to the direction of vibration. Thus, the vibration or direction of vibration is oriented at least approximately parallel to the perpendicular of the plane defined by the membranes. However, it is clear that such a design can also be achieved by any of the motion link solutions described above, and is therefore not limited to membranes.

[0015] The vibrating bearing may also be a ball bearing. In one embodiment, the tool holder may be designed to hold and fix the tool in various orientations such that the counter-cutting force generated due to the cutting force from the blank as the tool is fed in the feed direction is absorbed by the pulse spindle.

[0016] The above may lead to improved flexibility in tool holding devices. In one embodiment, the tool holder may be embedded in the housing by preferably two motion links, more preferably four motion links.

[0017] The above can improve stability and, along with accuracy. Furthermore, it can also improve the robustness of the tool holding device. The motion link may be a membrane fixed to the housing and tool holder. The membrane may be made of an elastic and durable material, such as steel or any other suitable material.

[0018] The membrane or motion link may be pre-tensioned when in the neutral position. As mentioned earlier, the purpose of the membrane is to direct vibrational movement in a specific direction along the perpendicular to the plane defined by the membrane. In other directions, the membrane keeps the tool holder fixed, at least more or less.

[0019] In another embodiment, the pulse spindle may include two or more protrusions on its side surface, which are preferably conical or inclined surfaces when viewed with respect to the longitudinal direction of the pulse spindle.

[0020] This could lead to an increase in the pulse and vibration frequencies. In yet another embodiment, a portion of the side surface of the pulse spindle is a smooth, uniformly shaped cylinder along its circumference, allowing for the selection of vibrations with zero amplitude.

[0021] The above is advantageous because the final micro-cutting should often be performed with the vibration switched off or with an amplitude equal to zero in order to produce a smooth surface.

[0022] In yet another embodiment, the tool holder may include a first part and a second part, the first part comprising a vibrating bearing, thereby connecting a motion link to the first part, and the second part being a tool-holding portion positioned to hold a tool, and thereby the first part and the second part being pivotable or movable relative to each other.

[0023] Generally, the direction of the pulse or vibration needs to be aligned with the feeding direction of the tool. In other words, if it is assumed that the tool reduces the diameter of the workpiece over a certain length measured in the z - direction and, accordingly, over a certain length measured in the longitudinal direction of the rotating spindle of the lathe, the vibration or pulse needs to be generated in the same z - direction; otherwise, the surface may become uneven. For example, when generating a groove or a combination of grooves and the feeding direction is along the x - direction, the vibration or pulse needs to be generated in the same x - direction. Of course, in order to generate an inclined shape, a curved shape, a convex shape, or a concave shape on the workpiece, a combination of the x - direction and the z - direction may also be possible, and the direction of the vibration can be adapted accordingly, because the first part and the second part of the tool holder may be pivotable or movable relative to each other. This will be described later in this specification by referring to a mechanism having two vibration units.

[0024] The second part may be provided with an adjustment mechanism for holding and adjusting the tool. The adjustment mechanism may be designed to fixedly hold the tool in a predetermined position. Thus, the adjustment mechanism may further include a screw and certain clamping elements so that the position of the tool on the tool holder can be adapted and changed.

[0025] In one embodiment, the tool holding device may include a motor, and the pulse spindle may be driven by the motor. The motor may be an electric motor, such as a servo motor, etc.

[0026] Using a separate motor for the pulse spindle can improve the flexibility and adjustability of the tool holding device. The frequency of the pulse can be adjusted, for example, by changing the motor speed.

[0027] Also, a motor such as a servo motor may be used to adjust the displacement of the pulse spindle along its longitudinal axis. Instead of a motor, the tool holding device may include a rotational transmission unit so that the pulse spindle can be driven from the rotary adapter of a turning machine. Even when a rotary adapter of a lathe or turning machine is used, a motor may be present to drive the longitudinal displacement of the pulse spindle.

[0028] In one embodiment, the tool holding device may comprise two or more elastic elements. This can help to adjust the elastic force used to generate vibrations and pulses. In yet another embodiment, the tool holding device may include a second vibration mechanism, which is: A tool holder for holding a tool, wherein the aforementioned tool holder is equipped with a vibrating bearing, At least one elastic element that abuts against the tool holder at one end and against the housing at the other end, A motion link is connected to the housing and the tool holder, and is used to movably embed the tool holder. A pulse spindle embedded in a housing, wherein the pulse spindle is substantially cylindrical and has sides interrupted by at least one protrusion.

[0029] At least one elastic element is positioned to push the tool holder toward the side of the pulse spindle, thereby causing the vibrating bearing to contact the side, and thus the rotation of the pulse spindle generates vibrations in the tool holder due to irregularities on the side of the pulse spindle, at which time a second vibrating mechanism is connected to the tool holder of the first vibrating mechanism such that a first vibration direction generated by the first vibrating mechanism is directed at an angle with respect to a second vibration direction generated by the second vibrating mechanism.

[0030] When using two vibration units or vibration units / mechanisms, as described in the previous paragraph, it is possible to vibrate the tool in both directions with an angle between them. The movement or vibration in the two directions must be synchronized, and the resulting amplitude can be adjusted so that the resulting vibration or vibration occurs in the tool feed direction. This allows the tool holding device to provide vibration to the tool in various feed directions, enabling the provision of a high-quality surface on the blank or workpiece.

[0031] In one embodiment, the tool holding device may include a support structure, in which the vibrator bearings of the first and second vibration mechanisms are embedded in separate casings that are part of the corresponding tool holder, thereby connecting each casing to the motion link of the first and second vibration mechanisms, respectively. The support structure may be connected to the casing of the first vibration mechanism, and the second vibration mechanism may be attached to the support structure.

[0032] The above embodiment may be useful in transmitting vibrations generated by the first vibration mechanism to the second vibration mechanism. The support structure may be a support plate or the like for easily attaching the second vibration mechanism.

[0033] The elastic element may be a spring, cylinder, elastomer, piston, or any other suitable pre-tensioning device. In one embodiment, the longitudinal directions of the two pulse spindles may be oriented parallel to each other.

[0034] The above can be simplified in terms of structure. In one embodiment, the angle between the first vibration direction and the second vibration direction may be selected to be 90 degrees, and therefore perpendicular.

[0035] This allows one vibration direction to be associated with a sine curve and the other vibration direction with a cosine curve, thus facilitating the calculation of direction and amplitude. By assembling two vibration units or two pulse spindles having different vibration directions, such as 90° or perpendicular to each other, the resulting chip fracture movement can follow the direction of tool movement. The amplitude must and can be adjusted in each direction, which is made possible using the present invention's tool holding device comprising two vibration mechanisms or vibration units.

[0036] In further embodiments, the tool holding device may include a gear mechanism, and the pulse spindles of the first and second vibration mechanisms may be interconnected with each other. This can lead to synchronization between pulsed spindles.

[0037] Furthermore, it is possible to implement motor control of the vibration amplitude in order to adjust and adapt in real time to follow any profile of the workpiece. Chip fracture must occur along the cutting direction to produce a smooth surface on the workpiece.

[0038] Furthermore, in this specification, the terms feed direction or feeding direction relate to the movement of the carriage relative to the workpiece, and therefore to the movement of the tool, and therefore to the direction in which the cutting tool is moving.

[0039] The direction of the force generated by at least one elastic element acts in the same direction as the cutting force generated by the feed direction or feed-in direction. In other words, this means that when the tool holding device is used and moved in the feed-in direction or feed direction, the pulse spindle and its sides provide support.

[0040] This specification also discloses a lathe equipped with a tool-holding device according to any of the embodiments described above. Explanation of terms used in this specification: to attach or attached In this specification, the terms “mounted” or “attached” include both versions of the mounted state, i.e., displaceable mounting or fixed mounting. For example, the pulse spindle may be displaceable mounting within the housing, while other parts are fixedly mounted.

[0041] Motion Link A motion link is designed as an elastic linkage mechanism that elastically connects the tool holder to the housing. That is, the tool holder moves guided relative to the housing and can always be in an idle position when no force is applied. Motion links are sometimes also called cam links, guides, or elastic guides.

[0042] Pulse spindle A pulse spindle is sometimes called a cam, but it is more appropriate to call it a pulse spindle because it generates pulses within the tool holder, thus best describing its function.

[0043] Elastic element The elastic element may be a spring, an elastomer, or a membrane, etc. The term elastic element encompasses all of these embodiments. Essentially, an elastic element can be designed as a device that has an elastic force that causes another structure to move elastically in a certain direction.

[0044] Vibrating bearing A vibrating bearing may be a cam follower. However, because this bearing rotates on a pulse spindle and may vibrate as a result, at least when the pulse spindle is in a certain position, a cam follower may also be called a vibrating bearing, or alternatively, a pulse spindle follower bearing, or simply a cam bearing or bearing.

[0045] Further aspects and exemplary embodiments are shown in the accompanying drawings and / or described below. [Brief explanation of the drawing]

[0046] [Figure 1] A schematic cross-sectional side view of a lathe equipped with the tool holding device according to the present invention is shown. [Figure 2] A schematic perspective view of the tool holding device according to the present invention is shown. [Figure 3] Figure 2 shows a schematic front view of the tool holding device. [Figure 4] A schematic diagram similar to Figure 2 is shown, but a portion of the housing has been removed for illustrative purposes. [Figure 5] A schematic perspective view of the tool holding device in different configurations is shown in Figure 4. [Figure 6] Another perspective view of the tool-holding device according to the present invention, with the housing removed at least partially, is schematically shown. [Figure 7] A schematic exploded view of the tool holding device according to the present invention is shown. [Figure 8a] A schematic diagram of another exemplary embodiment according to the present invention is shown. [Figure 8b] Another schematic diagram of the embodiment shown in Figure 8a is shown, in which part of the housing has been removed. [Modes for carrying out the invention]

[0047] The present invention will be described in more detail below with reference to the accompanying drawings, for illustrative purposes, by means of embodiments. To provide a more complete understanding of the present invention, specific details are described throughout the following description. However, the present invention may be carried out without these details. In other cases, well-known elements are not illustrated or described in detail to avoid unnecessarily obscuring the invention. Accordingly, this specification and the drawings should be considered illustrative rather than restrictive.

[0048] Figure 1 shows a cross-sectional view of a lathe or turning machine 100. The turning machine 100 comprises a machine bed 102 and a headstock 104 and tailstock side 106 interconnected to each other via the machine bed 102. The headstock 104 includes a rotary spindle 115 with a chuck 116 for holding a blank 108. The rotary spindle 115 is fixedly connected to the chuck 116. The headstock 104 also includes a motor (not shown in Figure 1) for driving rotation around the rotary spindle axis A of the lathe 100. Rotation rA is also shown in Figure 1. On the tailstock base 106 is a tailstock 114 with a dead center or rotation center for fixing a relatively long workpiece 108 or blank on the rotary spindle axis A. For short workpieces, a dead center or rotation adapter is not required. The lathe further comprises a carriage 110 that can move along the z-direction, the carriage 110 typically comprising a cross slide designed to hold a tool, the aforementioned cross slide configured for movement along the x-direction. The carriage 110 can be moved along a guide 118 and thus along a rotating spindle such as a lathe, which is in the z-direction. The guide 118 may be a linear guide or the like for the movement of the carriage 110. Figure 1 shows the general principle of a lathe 100, which has no limiting effect on the present invention. The carriage 110 comprises a tool holding device 1 that is slidable in the x-direction on the cross slide, the aforementioned tool holding device 1 comprising a tool 28, which is used to cut into a blank to produce a workpiece such as a rod having a specific diameter along its longitudinal extension. The invention disclosed herein relates to a tool holding device 1 for a lathe.

[0049] Figure 2 shows a tool holding device 1 for a turning machine or lathe 100, where the tool holding device 1 is separated from the lathe for illustrative purposes. The tool holding device 1 comprises a tool holder 12 for holding a tool 28. The tool holder 12 comprises a fixing mechanism 32 for removably mounting the tool 28 to the tool holder 12. The tool 28 itself comprises a replaceable cutting insert 29. The cutting insert 29 is designed to be driven or pressed into a rotating workpiece 108' fixed to the rotating spindle of the lathe 100. In Figure 2, the tool 28 is fed along the z-direction on the workpiece 108', this z-direction corresponding to the rotating spindle axis A in Figure 1. The arrow v indicates the direction of vibration, which will be described in more detail with reference to Figure 4. As can be seen from Figure 2, the direction of vibration corresponds to the feed direction, which is the z-direction. The housing 2 is fixed to the frame 16 (see Figure 4) using screws and / or rivets. The housing 2 is further connected to the frame 16 by means of bolts or screws, for example. The housing 2 is further connected to the lathe using bolts 3 that extend through the housing 2 and the frame 16. The embodiment of the tool holding device 1 shown in Figure 2 further comprises a gear 7 configured to be connected to a gear (not shown) of the lathe 100 to supply power to the drive spindle.

[0050] Figure 2 further illustrates the cutting force RF arising from the feed direction FD of the tool 28 and cutting insert 29 and the rotation of the workpiece. The cutting insert 29 is positioned to face the feed direction FD. The feed direction FD in Figure 2 shows how the tool holding device 1 moves relative to the workpiece or blank 108' during turning of the blank 108'. The cutting force RF arises from the feed direction FD and the resulting engagement between the tool 28 and the blank 108'. In Figure 2, the feed direction FD is parallel to the z-direction, which corresponds to the longitudinal direction of the blank 108'.

[0051] Furthermore, referring to the above, the tool holder 12 may be designed so that the tool 28 can be oriented according to the above even when the tool holder is rotated, for example, 90 degrees and therefore rotated in the x-feed direction as shown in Figure 5, or when rotated at any other angle. Further details regarding the feed direction FD and cutting force RF will be explained with reference to Figure 4. The tool holder 12 may be further designed so that the tool 28 can be moved linearly, as shown.

[0052] Although not shown in the figures herein, it should be noted that all embodiments of the tool holding device 1 as shown herein may be equipped with any type of motor instead of the gear 7 to drive the pulse spindle 6.

[0053] Figure 3 shows a front view of the tool holding device 1 of Figure 2. The tool 28 with the cutting insert 29 is clearly visible, as is the workpiece 108'. The tool holding device 1 further comprises a knob 23, which is used to adjust and control the amplitude of the vibration, as will be described later in this specification. Figure 3 further shows an arrow v indicating the direction of vibration v. Here again, the feed direction z is aligned with the z-direction to provide clear and smooth cutting.

[0054] Here, with reference to Figures 4, 5, and 6, which show the tool holding device 1 according to the present invention with the housing 2 removed, the details of the vibration mechanism 5 will be described. The vibration mechanism 5 is shown as drawing rotational energy from a lathe 100 or the like via a drive shaft 6 and transmitting that rotational energy to a pulse spindle 10 via a gear unit 14 or the like. The gear unit 14, the pulse spindle 10, and the drive shaft 6 are embedded in a frame 16, which comprises a plate having bearings for holding the drive spindle 10, the pulse spindle 6, and the gear unit 14.

[0055] The following description will be based on an embodiment in which the vibration mechanism 5 uses gears 7 to power the tool holding device 1, but those skilled in the art will understand that the vibration mechanism 5 can be driven using, for example, a servo motor or any other type of motor. The tool holding device 1 may have several motors to drive various functions of the vibration mechanism 5.

[0056] The pulse spindle 10 preferably has a side surface 21 with a diameter larger than the axis of the pulse spindle 10. The side surface 21 includes a surface 22, which is shown in the figures as an inclined surface or a conical surface 22. The conical surface 22 is embedded in the side surface 21 and is inclined with respect to the longitudinal axis a defined by the pulse spindle 10. The tool holder 12 includes a vibrating bearing 26, which is in contact with the side surface 21 of the pulse spindle 10 so that the vibrating bearing 26 can roll on the side surface 21 and the conical surface 22 as the pulse spindle 10 rotates. In the embodiments shown in Figures 4 to 6, the side surface 21 has four conical surfaces 22 around it. However, it is obvious that the side surface 21 may have one, two, three, four, five or any preferred number of conical surfaces 21 arranged preferably at regular intervals on the side surface 21. The tool holder 12 is attached to the frame 16 via motion links 8, which hold the tool holder 12 in a central position but allow it to move in a direction perpendicular to the longitudinal direction a of the pulse spindle 10. In the embodiments shown in Figures 4 to 6, four motion links 8 hold the tool holder 12 in place. The motion links 8 are designed to always elastically pull back or move the tool holder 12 back to the idle position, such that the vibrating bearing 26 is in contact with the side surface 21 while at least one elastic element 4 pre-tensions or pushes the tool holder 12 toward the pulse spindle 10. The vibrating bearing 26 is housed in a first portion 24 of the tool holder 12. The tool 28 is mounted within a second portion 27 of the tool holder 12, while the fixing mechanism 32 (see Figure 2) is also part of the second portion 27 of the tool holder 12. At least one elastic element 4 engages with the tool holder 12 on the opposite side of the vibrating body bearing 26, and at least one elastic element 4 abuts against the housing 2 or frame 16 at one end and against the tool holder 12, preferably the first portion 24, at the other end. In the illustrated embodiment of Figure 4, five elastic elements 4 are shown in the tool holding device 1.Naturally, any number of elastic elements 4, such as two, three, four, or five, can be used, depending on their strength and the elastic force required to ensure clear and distinct vibrations. Furthermore, although the elastic elements 4 in the figure are shown as springs, the elastic elements 4 may be elastomers, cylinders, hydraulic cushions, air springs, etc. From Figure 4, it can be understood that the rotation of the pulse spindle 10 generates vibrations or oscillations in the tool holder 12 due to the elastic force generated by the elastic elements 4 and the uneven surface of the side surface 21 of the pulse spindle 10 in the exemplary embodiment, shown as a machined conical or inclined surface 22 on the side surface 21. Furthermore, the amplitude of the vibrations or oscillations can be adjusted by displacing the pulse spindle 10 along its longitudinal axis a, and thus it can be understood that the amplitude decreases when the displacement of the pulse spindle 10 along its longitudinal axis a or side surface 21 moves away from the gear unit 14 towards the knob 23, while the amplitude of the pulses and vibrations increases with displacement away from the knob 23 towards the gear unit 14.

[0057] Referring particularly to Figure 4, details regarding the feed direction FD and the resulting cutting force RF will be explained. The feed direction FD is related to the direction of movement of the tool holding device 1 during turning, as previously mentioned. The resulting forces between the blank 108, the cutting insert 29, and the tool 28 are the cutting force RF, which needs to be absorbed in the tool holding device 1. In order to obtain a smooth and good quality turned surface on the blank 108', this cutting force RF needs to be absorbed by the pulse spindle 10 and the side 21, respectively, via the counter-cutting force RF' shown by the dashed line in Figure 4. If this counter-cutting force RF' is absorbed by the elastic element 4, the quality of the turned surface of the blank 108' may be reduced because it may be impossible for the elastic element 4 to absorb such a reaction force without deformation. Therefore, in order to avoid such deformation, the spring force or elastic force of the elastic element 4 may be adapted so that it is greater than the reaction force RF. The same applies when the tool 28 is rotated 90 degrees around the x-axis and 90 degrees around the y-axis for radial turning of the blank 108', as shown in Figure 5.

[0058] Figure 5 shows another orientation of the tool 28, where the tool holding device 1 is configured to turn radially around the blank 108'. Here again, the feed direction FD and cutting force RF are shown, and it can be seen that in this case as well, the pulse spindle 10 absorbs the cutting force RF with the counter-cutting force RF'. The cutting insert is not visible in Figure 5. The feed direction FD in Figure 5 is parallel to the x-direction, which is essentially radial when viewed from the blank 108'.

[0059] Figures 4 and 5 clearly show that, regardless of the feed direction FD, in order to ensure a high-quality finish on the blank, the cutting insert 29 and the tool 28 must be oriented so that the counter-cutting force RF' is absorbed or generated by the pulse spindle 10. As mentioned above, the tool holder 12 may be designed to change the orientation of the tool 28 in order to absorb the counter-cutting force RF' by the pulse spindle 10.

[0060] Although not clearly visible in the diagram, the side surface 21 can be designed such that, when viewed circumferentially around the pulse spindle 10, a portion of the side surface 21 does not include any cone or inclined surface 22, or does not have a cone or inclined surface 22. Note that this means the amplitude of the pulse or vibration can be null or zero, and consequently, vibration is absent at at least one position along the longitudinal axis of the pulse spindle 10. This makes it possible to turn off vibration at the required position and when required.

[0061] Next, the displacement of the pulse spindle 10 along its longitudinal axis a may be adjusted using the knob 23. However, as those skilled in the art will understand, it is possible to perform the displacement automatically using a motor or servo motor.

[0062] The second portion 27 of the tool holder 12 extends to one side of the first portion 24 in such a manner that the tool 28 can be easily extended and engaged with the blank or workpiece 108'.

[0063] In a preferred embodiment, the second portion 27 can be pivoted relative to the first portion 24 of the tool holder 12, as described with reference to Figure 5. The pivoting movement may be performed using a motor or manually using screw fastening or the like (not shown in the figure). Again, the pivoting may also be performed automatically using a servo motor and interface or the like.

[0064] Figure 5 shows the vibration direction v, which in this case is adjusted to match the x-feed direction x of the tool 28. Here again, for example, if it is necessary to cut grooves or the like into the workpiece 108', the vibration direction v is selected to be parallel to the feed direction x in order to produce smooth cutting. Note that in the case of feeding, preferably the entire tool holding device 1 moves along the feed direction. However, in another embodiment (not shown), the movement of the tool holder 12 along the feed direction may also be included. The vibration mechanism 5 disclosed herein does not preclude such solutions.

[0065] Referring now to Figure 6, which provides a more detailed description of the vibration mechanism 5, the further details are best visible and understandable in Figure 6. The vibrating bearing 26 embedded in the first portion 24 of the tool holder 12 is clearly visible. The vibrating bearing 26 is embodied, for example, in the form of a roller mounted within the first portion 24 via a bearing. The vibrating bearing 26 can be made of a suitable material so as to conform tightly to the side surface 21 of the pulse spindle 10. The elastic element 4 abuts at one end against a removable spring bracket mounted in the frame 16 or housing 2, and also abuts against the first portion 24, which is the bearing bracket of the tool holder 12, and the tool holder 12 is movably embedded or mounted in the frame 16 via a motion link 8.

[0066] In all embodiments disclosed herein, the motion link 8 is shown in the form of a membrane made of, for example, metal or any other suitable material. Alternatively, in any of the embodiments shown herein, the motion link (not shown) may be formed as a spring, elastomer, air damper, cylinder, or any other suitable solution.

[0067] Furthermore, according to any embodiment of this specification, the pulse spindle 10 may also include a cylindrical portion 9 with a side surface 21 and an inclined surface 22 or irregularities 22, as shown in Figure 6, so that the cylindrical portion 9 can be replaced with another cylindrical portion having a different inclined surface or other irregularities than those shown in the embodiments of this specification, for example, to vary the frequency or amplitude and / or motion curve. Those skilled in the art will understand this concept based on the above hints.

[0068] Figure 7 shows an exploded view of the tool holding device according to the present invention. The housing 2 is shown in a separated state, and from Figure 7 it is clear how the cylindrical portion 9 with sides 21 is separated from the shaft 11 of the pulse spindle 10. The cylindrical portion 9 is fixed to the central portion 11 via screws so that it can be replaced. A motion link 8 in the form of a membrane is clamped or positioned in a slot 13 of the frame 16. Screws and bolts 3 are used to mount the housing 2 to the lathe. From Figure 7 it is also clear that the elastic element 4 abuts the first portion 24 of the tool holder 12 at one end, and depending on the selected solution, the other end of the elastic element 4 can abut the housing 2. The drive shaft 6 and pulse spindle 10 are rotatably mounted to bearings or the like in the frame 16.

[0069] In the embodiment shown in the figure, the tool holding device 1 is shown to include one vibration mechanism 5. However, it is possible to install two vibration mechanisms within the tool holding device, which are oriented to provide vibration directions that are angled or perpendicular to each other.

[0070] Such embodiments having two vibration mechanisms are shown in Figures 8a and 8b. The tool holding device 1' according to Figure 8a comprises a housing 2' into which two pulse spindles 10, 10' and, consequently, two vibration mechanisms 5, 5' are embedded, so that vibration can be provided in two directions. For this reason, the angle between the two directions is preferably 90° so that cosine and sine calculations can be used. However, other angles are also possible between the two vibration directions. For illustrative purposes, Figure 8a further shows a tool 28 and a cutting insert 29 as well as a blank 108'.

[0071] Providing the tool holding device 1' with two vibration directions may be even more advantageous when it is necessary to generate surfaces on the blank 108' that have varying inclines and / or surfaces that are not oriented perpendicular or parallel to the feed direction.

[0072] Referring now to Figure 8b, the same embodiment as in Figure 8a is shown, but the housing 2' has been removed for illustrative purposes. Details of the tool holding device 1' shown in Figure 8b are now described. The tool holding device 1' comprises a first vibration mechanism 5 and a second vibration mechanism 5'. The second vibration mechanism 5' is incorporated into the first vibration mechanism 5, and thus the two vibration mechanisms 5, 5' generate a first vibration direction v1 in one direction and a second vibration direction v2 directed at an angle α with respect to the first vibration direction v2. Each of the first vibration mechanism 5 and the second vibration mechanism 5' comprises a pulse spindle 10, 10' having a side surface 21 including at least one irregularity 22 in the form of a milled or inclined surface for generating vibration and pulses, a vibrating body bearing 26, 26' designed to contact the side surface 21, and a motion link 8 for holding the contact element or vibrating body bearing 26 so as to be movable in a particular direction, which corresponds to a first vibration direction v1 and a second vibration direction v2, respectively. Each of the first vibration mechanism 5 and the second vibration mechanism 5' further comprises at least one elastic element 4, 4' which pre-tensions the respective vibrating body bearings 26, 26' toward the side surface 21 to generate pulses when the respective pulse spindles 10, 10' are rotating. The rotation of the pulse spindle 10 of the first vibration mechanism 5 is synchronized with the pulse spindle 10' of the second vibration mechanism 5' via a gear device 15' embodied as a belt drive. Furthermore, the gear device 15 may be implemented as a purely electrical connection, a gear device using gears, or a magnetically driven rotational force transmission device.

[0073] The tool holder 12 is connected to the first part 24' of the second vibrating mechanism 5' and holds a tool 28 having a cutting insert 29. The tool holder 12 may be pivotable relative to the first part 24 of the first vibrating mechanism 5.

[0074] The second vibration mechanism 5' is connected to the first part 24 of the first vibration mechanism 5 via a support structure 35 coupled to the first part 24. The first part 24 includes a casing for holding a vibrator bearing 26, and the support structure 35 is connected to the casing of the first part 24 so that vibrations can be optimally transmitted from the first vibration mechanism 5 to the second vibration mechanism 5'. The first part 24' of the second vibration mechanism 5' is more clearly visible, where the casing holds the vibrator bearing 26'. Note that the support structure 35 is freely movable and is connected only to the first part 24 of the first vibration mechanism 5.

[0075] Note that the longitudinal directions of the pulse spindles 10, 10' in the embodiments shown in Figures 8a and 8b are oriented parallel to each other. This may be feasible for some applications, but is not necessarily required. Furthermore, in order to independently change the amplitudes of the first vibration direction v1 and the second vibration direction v2, each of the sides 21, 21' of the first vibration mechanism 5 and the second vibration mechanism 5' can be moved independently along the corresponding pulse spindles 10, 10'.

[0076] Each of the first vibration mechanism 5 and the second vibration mechanism 5' may further comprise bases 39, 39' which hold at least a portion of the pulse spindles 10, 10' and the motion links. The bases 39, 39' may be located at the lower ends of the first and second vibration mechanisms. The pulse spindles 10, 10' may further be embedded in frames 16, 16'. The bases 39, 39' may be provided for rigidity purposes and can be embodied in any embodiment shown herein.

[0077] The tool holding devices described herein may be equipped with various motors and servo motors to enable automatic or at least remote control of the turning process. The tool holding devices may also be coupled to drive shafts for the driven tools of the lathe.

[0078] Various features have been described herein as existing in “several embodiments,” “another embodiment,” or “yet another embodiment,” etc. Such features are not essential and may not be present in all embodiments. Embodiments of the present invention may include zero, any one, or any combination of two or more such features. This is limited to the extent that a person skilled in the art cannot construct a practical embodiment combining such incompatible features, insofar as certain features among such features are incompatible with other features among such features. Therefore, the description that “several embodiments,” “another embodiment,” or “yet another embodiment,” etc., have feature A, and “several embodiments” have feature B, should be interpreted as an explicit indication that the inventors also envision embodiments combining feature A and feature B (unless otherwise stated in the description, or unless feature A and feature B are fundamentally incompatible).

Claims

1. A tool holding device (1) for a turning machine, the tool holding device comprising a housing (2) and a first vibration mechanism (5), the first vibration mechanism (5) A tool holder (12) for holding a tool (28), wherein the tool holder (12) is equipped with a vibrating bearing (26), At least one elastic element (4) that abuts against the tool holder (12) at one end and against the housing (2) at the other end, A motion link (8) is connected to the housing (2) and the tool holder (12) and is used to movably embed the tool holder (12), A pulse spindle (10) is mounted on the housing (2), wherein the pulse spindle (10) has a side surface (21), the side surface (21) is substantially cylindrical and interrupted by at least one protrusion (22), and Equipped with, The at least one elastic element (4) is positioned to push the tool holder (12) toward the side surface (21) of the pulse spindle (10) so that the vibration bearing (26) abuts against the side surface (21) so that the rotation of the pulse spindle (10) causes vibration in the tool holder (12) due to the irregularities (22) on the side surface (21) of the pulse spindle (10), and the pulse spindle (10) is positioned toward the side surface ( A tool holding device (1) is displaceably mounted to the housing (2) so as to be displaceable along the longitudinal axis (a) of the pulse spindle (10), wherein the at least one protrusion (22) is a surface (22) that is inclined when viewed along the longitudinal axis (a) of the pulse spindle (10), so that the contact point between the pulse spindle (10) and the vibrating body bearing (26) is selectable along the longitudinal axis (a), and the amplitude of vibration is changeable and adjustable.

2. The tool holder (1) is designed to hold and fix the tool (28) in various orientations such that the counter-cutting force (RF') generated due to the cutting force (RF) from the blank (108, 108') when the tool (28) is fed in the feed direction (FD) is absorbed by the pulse spindle (10).

3. The tool holder (12) is attached to the housing (2) by two motion links (8), the tool holding device (1) according to claim 1.

4. The tool holding device (1) according to claim 3, wherein the motion link (8) is a vibrable membrane.

5. The tool holding device (1) according to any one of claims 1 to 4, wherein the pulse spindle (10) includes one or more irregularities (22) on the side surface (21).

6. The tool holding device (1) according to any one of claims 1 to 5, wherein a portion of the side surface (21) is a smooth, uniformly shaped cylinder along the circumference, without any irregularities (22), so that vibrations having zero amplitude can be selected.

7. The tool holder (12) comprises a first portion (24) and a second portion (25), the first portion (24) comprises the vibrating body bearing (26), the motion link (8) is connected to the first portion, the second portion (27) is a tool holding portion including the tool holder (12) and the tool (28), and the first portion (24) and the second portion (27) are pivotable relative to each other, the tool holding device (1) according to claim 3.

8. The tool holding device (1) according to claim 7, wherein the second portion (27) comprises an adjustment mechanism (32) for holding and adjusting the tool (28).

9. The tool holding device (1) according to claim 1 further comprises a motor, wherein the pulse spindle (10) is driven by the motor.

10. The tool holding device (1) according to claim 1 is a tool holding device (1) comprising a rotation transmission unit such that the pulse spindle (10) can be driven from the rotation adapter of the turning machine.

11. The tool holding device (1) according to claim 1 comprises a second vibration mechanism (5'), the second vibration mechanism (5') is A tool holder (12') for holding a tool (28), wherein the tool holder (12) is equipped with a vibrating bearing (26), and At least one elastic element (4') that abuts against the tool holder (12') at one end and against the housing (2) at the other end, A motion link (8') is connected to the housing (2') and the tool holder (12') and is used to movably embed the tool holder (12'), A pulse spindle (10') mounted on the housing (2'), wherein the pulse spindle (10') is substantially cylindrical and has a side surface (21') interrupted by at least one protrusion (22'), comprising: The tool holding device (1) is configured to push the tool holder (12') toward the side surface (21') of the pulse spindle (10') such that the rotation of the pulse spindle (10') is caused by the irregularities (22') of the side surface (21') of the pulse spindle (10') by the vibration bearing (26') contacting the side surface (21'), and the second vibration mechanism (5') is connected to the tool holder (12) of the first vibration mechanism (5) such that the first vibration direction (v1) generated by the first vibration mechanism (5) is directed at an angle to the second vibration direction (v2) generated by the second vibration mechanism (5').

12. The tool holding device (1) according to claim 11 comprises a support structure (35), wherein the vibrating bearings (26, 26') of the first vibrating mechanism (5) and the second vibrating mechanism (5') are mounted on separate casings which are part of the corresponding tool holders (12, 12'), each casing is connected to the motion links (8, 8') of the first and second vibrating mechanisms (5, 5'), the support structure (35) is connected to the casing of the first vibrating mechanism (5), and the first vibrating mechanism (5') is mounted on the support structure (35).

13. The tool holding device (1) according to claim 11, wherein the longitudinal directions of the pulse spindles (10, 10') of the first vibration mechanism (5) and the second vibration mechanism (5') are oriented parallel to each other.

14. The tool holding device (1) according to claim 11, wherein the angle (α) between the first vibration direction (v1) and the second vibration direction (v2) is selected to be 90 degrees, and therefore perpendicular.

15. The tool holding device (1) according to claim 11 further comprises a gear device (15), wherein the pulse spindles (10, 10') of the first vibration mechanism (5) and the second vibration mechanism (5') are interconnected with each other via the gear device (15).

16. A lathe comprising a tool holding device (1) according to any one of claims 1 to 15.

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