Device for transforming and transmitting mechanical vibrations to at least one mass

Abstract

The invention relates to a device for transforming and transmitting mechanical vibrations to at least one mass (30). The mass (30) is mechanically connected to at least two clamping bodies (10, 20) in the vibration propagation direction between said tensioning bodies by means of compressive stress. At least the clamping bodies (10, 20) are designed with the mass (30) as a component of a resonance system. An excitation vibration is introduced into the resonance system via a clamping body (10) by means of vibration transformation, the frequency of which excitation vibration substantially corresponds to the resonance frequency of the resonance system, with the result that the resonance system vibrates.

Description

[0001] DEVICE FOR TRANSFORMING AND TRANSMITTING MECHANICAL VIBRATIONS TO AT LEAST A MASS

[0002] The invention relates to a device for transforming and transmitting mechanical vibrations to at least one mass 30.

[0003] Background of the invention

[0004] The present invention relates to a device for transforming and transmitting an oscillating motion to at least one mass 30, in particular a tool.

[0005] To generate mechanical vibrations of solid masses 30, it is known that they are excited by excitation vibrations, such as ultrasound.

[0006] The invention is based on the objective of providing a device for transforming and transmitting an oscillating motion to a relatively heavy mass 30 with high frequency and / or high amplitude in a cost-effective and simple form.

[0007] This problem is solved according to the invention by the device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1. Advantageous embodiments of the device according to the invention are specified in the dependent claims.

[0008] According to the invention, a device for transforming and transmitting an oscillating motion to at least one mass 30 is provided, wherein the mass(s) 30 is mechanically connected to at least two clamping bodies (10, 20) in the direction of oscillation propagation via a compressive stress, and at least the clamping bodies (10, 20) with the mass 30 are designed as part of a resonance system, and an excitation oscillation is introduced into the resonance system via a clamping body 10 by means of oscillation transformation, the frequency of which essentially coincides with the resonance frequency of the resonance system, so that the resonance system oscillates.

[0009] The vibration is preferably a standing wave with a defined direction of propagation. The mass 30 is arranged between the clamping elements (10, 20) in the direction of vibration propagation.

[0010] Preferably, the excitation frequency should exactly match the resonance frequency. However, in practice, deviations of the excitation frequency from the resonance frequency are permissible, whereby the excitation frequency fs can lie in the range of fs = 0.8 ... 1.2 fr. Here, fr defines the resonance frequency.

[0011] The resonant oscillation lies in the range of 10-60 kHz, preferably between 17 and 30 kHz, e.g. 20 kHz.

[0012] Due to the mechanical connection of mass (n) 30 with the clamping elements (10, 20), mass (n) 30 also oscillates at approximately the same or exactly the same frequency when the clamping elements (10, 20) exhibit resonance behavior. The two resonantly tuned clamping elements (10, 20) with at least approximately the same resonant frequency thus form at least part of the resonant system.

[0013] According to the invention, a device is provided for the transformation and transmission of an oscillating motion on at least one mass 30, wherein the mass(s) 30 are mechanically connected to at least two clamping bodies (10, 20) in the direction of vibration propagation via a compressive force, and the clamping body 20 projects into the clamping body 10. For this purpose, the clamping body 10 has a blind hole that is not completely through-hole. The compressive force can be generated by means of a screw connection, preferably a threaded connection, (11, 21) between the clamping bodies (10, 20). Thread 11 belongs to clamping body 10.

[0014] Thread 21 belongs to clamping body 20.

[0015] The clamping body 10 and / or clamping body 20 may contain geometric modifications, such as key surfaces, bores, in order to be able to apply at least one torque for the rotation of the clamping body 20 relative to the clamping body 10.

[0016] The vibration transformation is a transformation of the vibration in its propagation direction and amplitude, preferably a transformation of the vibration direction between 10° and 90°, e.g. 90°.

[0017] In the area of ​​the vibration node of the longitudinally oscillating clamping body (10, 20) a radial vibration is generated.

[0018] The transformation of the vibration direction is carried out via the radial excitation of the longitudinally vibrating clamping body 10, preferably at its vibration node area of ​​the longitudinally vibrating clamping body 10.

[0019] The radial excitation of the longitudinally oscillating clamping body 10 results in a transformation of the amplitude of the oscillation in the longitudinal direction of oscillation.

[0020] The ratio of the amplitude transformation is between 0.1 and 10, preferably between 0.7 and 5, e.g. 3.

[0021] The advantage of the device according to the invention lies particularly in the fact that, by positioning the mass(s) 30 between the clamping elements (10, 20), the device is very compact in its design. The length of the resonance system of the device, in the direction of vibration, is in the range of a resonance length of an integer multiple of 1 to 1.5 x Lambda / 2, preferably in the range of a resonance length of 1 to 1.5 x Lambda / 2.

[0022] The length of the clamping element 10 in the direction of vibration lies in the range of a resonance length of an integer multiple of 1 to 1.5 x Lambda / 2, preferably in the range of a resonance length of 1 to 1.5 x Lambda / 2.

[0023] The length of the clamping element 20 in the direction of vibration lies in the range of a resonance length of 0.5 to 1.5 * Lambda / 2 * X, where X is preferably between 1 and 10, e.g. 1.

[0024] The influence of mass 30 on the resonance frequency must be taken into account and, if necessary, compensated for by geometric adjustments to the resonance system. One such adjustment could be, for example, shortening one or both clamping elements by the thickness of mass 30, so that mass 30 becomes a component of one or both clamping elements and thus also a component of the resonance system. This means that, depending on the clamping force, parts of mass 30 can theoretically be incorporated into the mass of the clamping elements, thus reducing the mass 30 to be accelerated.

[0025] No tensile stresses occur on at least one mass 30; only compressive forces act on the mass(s) 30. It is well known to those skilled in the art that the permissible compressive stresses of most solid materials are significantly higher than the permissible tensile stresses. Permissible tensile and compressive stresses are understood to be the stresses that a body made of the respective solid material can withstand without undergoing plastic deformation.

[0026] During the oscillation of at least one mass 30 with a relatively high frequency and high amplitude, the greatest forces acting on this mass(s) 30 are the inertial forces, which depend on its size (or weight) and its acceleration. The greater the permissible stresses, the greater the permissible forces acting on the mass(s) 30 can be. If the mass 30 remains constant, the acceleration of the mass(s) 30 can therefore be set higher. This means that, in the case of an oscillation, the mass(s) 30 can oscillate with a higher frequency and / or a greater amplitude than is the case with conventional mass oscillations. According to the invention, at least one heavier mass 30 can be accelerated with a conventional frequency or amplitude, or conversely, at least one conventional mass 30 can be accelerated with a higher frequency and a greater amplitude.

[0027] In one embodiment of the device according to the invention, the clamping body 10 is provided to include at least one additional blind hole 22, which is not centrally located and extends in depth to the almost vibration-free point of the clamping body 10, such as at a vibration node where a zero crossing of the longitudinal vibration pattern is observed. At the almost vibration-free point, the additional blind hole(s) 22 provide a means of supporting the device in its position and absorbing forces.

[0028] In one embodiment of the device according to the invention, it is provided that the clamping body 10 and / or clamping body 20 contains at least one transverse bore in order to add or remove additional media in its blind bore or through bore.

[0029] In one embodiment of the device according to the invention, the clamping body 10 is provided to have a through-hole with a locking element 12, e.g. a locking washer.

[0030] This has the advantage that the more complex blind drilling is eliminated and the mass(s) 30 can be removed more quickly after loosening the screw connection by removing the locking element.

[0031] In one embodiment of the device according to the invention, the resonance system is formed by the clamping elements (10, 20) and the mass(s) 30. The frequency of the excitation oscillation that is introduced corresponds to the resonance frequency of the resonance system formed by the clamping elements (10, 20).

[0032] The natural frequency of mass(s) 30 is different from the excitation frequency. Mass 30 can advantageously be configured as a tool. This means that the mass(s) 30 configured as a tool is set into an oscillating motion by the clamping elements (10, 20) between these clamping elements (10, 20), whereby the oscillating motion of the tool can be used for a machining operation.

[0033] According to the invention, a device for generating an oscillating motion of at least one mass 30 is further provided, comprising the mass(s) 30, which may in particular be a tool, and a resonance system with which the mass(s) 30 can be accelerated. The device includes a vibration generator 40 with which an excitation vibration can be generated whose frequency essentially coincides with the resonance frequency of the resonance system. According to the invention, at least two clamping elements (10, 20) are part of the resonance system, wherein the mass(s) 30 are mechanically connected to the clamping elements (10, 20) such that they are fixed between the clamping elements (10, 20). That is to say, when a longitudinal vibration is applied, the mass(s) 30 are fixed between the clamping elements (10, 20) in the direction of vibration propagation.An ultrasonic transducer is preferably used as the vibration generator 40, so that the excitation vibrations are ultrasonic vibrations.

[0034] In one embodiment of the device according to the invention, it is provided that in the direction of propagation of the vibration a parallel arrangement of the mass(s) 30 and the mechanical connection between the clamping elements (10, 20) exists.

[0035] The mechanical connection is preferably a screw connection, that is, a mechanical connection that can optionally also exert a clamping force on the mass(s) 30. This clamping force provides both a positive locking and a force-fit fixing of the mass(s) 30. The position of the mechanical connection, and thus also of the mass 30, is preferably at a vibration maximum, that is, at the point of maximum amplitude of the respective two clamping elements (10, 20).

[0036] The clamping elements (10, 20) and the mass(s) 30 oscillate synchronously with the clamping force as a resonant system, so that there is no risk of either of the clamping elements (10, 20) detaching from the mass(s) 30. Due to their resonant behavior, the stresses resulting from the dynamic loads on the mechanical connection are kept low.

[0037] The clamping force is applied via the threads 11 and 21 of the clamping elements (10, 20) at a virtually vibration-free point on the clamping elements (10, 20), such as at a vibration node where a zero crossing of the vibration pattern is observed in the longitudinal direction. This clamping at the zero crossings is preferably implemented on both clamping elements (10, 20).

[0038] The oscillating motion of the tool is converted into the movement of a work-performing element, such as a cutting edge for machining, a laser for cutting, welding, or flame cutting, or a cleaning element. However, a preferred application is the machining of a workpiece. Such machining can include, for example, ultrasonically assisted wire drawing, profile drawing, tube drawing, external turning, internal turning, cutting with a circular knife, sawing with a circular saw, milling with a disc cutter, or honing.

[0039] Alternatively, the device according to the invention can be used to excite mass(s) 30 for the treatment of liquids with cavitation.

[0040] The present invention will be explained below with reference to the exemplary embodiments shown in the accompanying drawings.

[0041] It shows

[0042] Fig. 1: Sectional view of mass excitation with a mass

[0043] Fig. 2: Sectional view of mass excitation with multiple masses

[0044] Fig. 3: from Fig. 1: view from the right: geometric variants of the clamping body 10

[0045] Fig. 4: from Fig. 1 with additional blind hole 22

[0046] Fig. 5: from Fig. 1: clamping body 10 with through hole and locking element

[0047] Figure 1 shows a section view of a device according to the invention for generating an oscillating motion of a mass 30. The device comprises a first clamping element 10 and a second clamping element 20, with the mass 30 arranged between these clamping elements (10, 20). The mass 30 can, for example, be configured as a tool, as will be described further below. To achieve a positive-locking connection of the mass 30, a mechanical connection in the form of a screw connection, preferably a threaded connection (11, 21), is provided between the clamping elements (10, 20). In this case, the mechanical connection (11, 21) achieves not only a positive-locking fixation of the mass 30, but also a force-locking fixation. Furthermore, the two clamping elements are mechanically connected to each other.By attaching the clamping element(s) 20 to the threaded shoulders 11 and 21, a pressing force can be exerted on the mass(s) 30 by rotating the clamping element 20 relative to the clamping element 10, so that the mass(s) 30 between the clamping elements (10, 20) is subjected to opposing compressive forces. A vibration generator 40, for example an ultrasonic transducer, is arranged on the first clamping element 10. This vibration generator 40 generates, for example, a standing, longitudinal wave. By designing at least the first clamping element 10 and the second clamping element 20 as a resonance system, these clamping elements are excited when an excitation frequency is generated that corresponds to the resonance frequency of the resonance system, such that they oscillate longitudinally in the direction of vibration propagation. This leads to an oscillating motion of the mass(s) 30.

[0048] As can be seen in Fig. 1, two resonant clamping elements are subjected to clamping forces F by means of the threaded connection (11, 21), so that the mass(s) 30 arranged between the clamping elements (10, 20) is subjected to these forces F. This means that a compressive load acts on the vibrating materials. The points where the clamping forces F are introduced into the clamping elements correspond to the zero points or nodes of vibration 0, which the shaft shown alongside has.

[0049] Referring to Fig. 1, this means that the positions of the first threaded shoulder 11 and the second threaded shoulder 21 are the points of application of the clamping forces F and are simultaneously located at the zero points or vibration nodes 0. It is evident that the mass 30 is located within the region of the amplitude A. Thus, when a vibration, such as ultrasound, is introduced into the resonance system, the clamping points, namely the threaded shoulders 11 and 21, are essentially not subject to the vibrations, while the clamping area of ​​the mass 30 vibrates in the direction of vibration propagation during resonance behavior. This is also evident from the fact that the points of application of the clamping forces are located almost at the midpoint of each half-wavelength X.

[0050] Fig. 2 shows that the number of masses 30 is not limited to the embodiment shown in Fig. 1, but that it can also be provided that several different masses 30 are connected to at least one of the clamping elements by positive and / or force-fit.

[0051] Fig. 3 shows the variations of the geometry of the clamping body 10.

[0052] Figure 4 shows that the clamping body 10 contains at least one additional blind hole 22, which is not centrally located and extends to a depth of almost vibration-free point on the clamping body 10, such as at a vibration node where the longitudinal vibration pattern exhibits zero crossing in the longitudinal direction. At this almost vibration-free point, the additional blind hole(s) 22 provide a means of supporting the device in its position and absorbing forces.

[0053] Fig. 5 shows the variant of the clamping body 10 in an embodiment in which the clamping body 10 contains a through-hole with a locking element 12, e.g. a locking washer.

[0054] This has the advantage that the more complex blind drilling is eliminated and the mass(s) 30 can be removed more quickly after loosening the screw connection by removing the locking element. The clamping force must always be greater than the acceleration force to prevent a loose connection of the mass 30. The following calculation will show which technological parameters can be optimized according to the invention.

[0055] The following is the goal: with

[0056] F a = Contact force [N]

[0057] Fb = acceleration force [N],

[0058] The acceleration force Fb is calculated as: b = m • a with m = mass [kg] a = acceleration [m / s²] 2 ].

[0059] The following relationship exists: with r = radius [m] w = angular frequency [1 / s]

[0060] A = mathematical amplitude (oscillation width) [m] f = frequency [1 / s; Hz]

[0061] This results in:

[0062] If F a The possible achievable amplitude, which has been determined from the permissible voltage, is thus derived from:

[0063] By rearranging the formula to solve for the frequency, the maximum frequency can be determined from the mathematical relationship shown.

[0064] Practical amplitudes are, for example, in the range of 1–200 m, preferably 70 pm, at a frequency of 10–60 kHz, preferably between 17 and 30 kHz, e.g., 20 kHz. (List of reference symbols)

[0065] 10 First clamping element

[0066] 11 First threaded section

[0067] 12 safety element

[0068] 20 Second clamping body

[0069] 21 Second threaded section

[0070] 22 Blind hole drilling

[0071] 30 mass

[0072] 40 vibration generators

[0073] A amplitude

[0074] Zero point, node

[0075] F Contact force

[0076] X wavelength

Claims

PATENT CLAIMS 1. A device for transforming and transmitting an oscillating motion to at least one mass 30 is provided, wherein the mass(s) 30 is mechanically connected to at least two clamping bodies (10, 20) in the direction of oscillation propagation via a compressive stress, and at least the clamping bodies (10, 20) with the mass 30 are designed as part of a resonance system, and an excitation oscillation is introduced into the resonance system via a clamping body 10 by means of oscillation transformation, the frequency of which is essentially the same as the resonance frequency of the resonance system, so that the resonance system oscillates.

2. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, wherein the resonant oscillation is in the range of 10-60 kHz, preferably between 17 and 30 kHz, e.g. 20 kHz.

3. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, wherein at least one mass 30 is arranged in the direction of oscillation propagation between the clamping bodies (10, 20).

4. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, wherein the vibration transformation is a transformation of the vibration in its propagation direction and amplitude, preferably a transformation of the vibration direction between 10° and 90°, e.g. 90°, and the transformation of the vibration direction via lateral excitation of the longitudinally oscillating clamping body 10, preferably at its region of the vibration node of the longitudinally oscillating clamping body 10.

5. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, in which at least one mass 30 is mechanically connected to at least two clamping bodies (10, 20) in the direction of oscillation propagation via a compressive stress, the clamping body 10 has a blind hole bore which is not completely through and the clamping body 20 projects into the clamping body 10.

6. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, in which at least one mass 30 is mechanically connected to at least two clamping bodies (10, 20) in the direction of oscillation propagation via a compressive stress, the clamping body 10 has a through-hole which contains a locking element and the clamping body 20 projects into the clamping body 10.

7. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, comprising at least one mass 30, in particular a tool, and a resonance system with which at least one mass 30 can be accelerated, as well as a vibration generator 40 with which an excitation vibration can be generated whose frequency substantially coincides with the resonance frequency of the resonance system, characterized in that the resonance system includes at least two clamping elements (10, 20) with which at least one mass 30 is mechanically connected in such a way that at least one mass 30 is fixed between the clamping elements (10, 20).

8. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, wherein the mass(s) 30 are mechanically connected to at least two clamping bodies (10, 20) in the direction of oscillation propagation via a compressive stress, and the generation of the compressive stress is effected by means of a screw connection, preferably a threaded screw connection, (11, 21) between the clamping bodies (10, 20) such that the thread 11 belongs to clamping body 10 and that the thread 21 belongs to clamping body 20.

9. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, in which at least one mass 30 is clamped by both clamping bodies (10, 20) subjected to a clamping force (F).

10. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, in which clamping body 10 and / or clamping body 20 may contain geometric modifications, such as key surfaces, bores, in order to be able to apply at least one torque for the rotation of the clamping body 20 relative to the clamping body 10.

11. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to claim 1, wherein the length of the resonance system of the device, in the direction of oscillation, is in the range of a resonance length of 1 to 1.5 x Lambda / 2, the length of the clamping element 10 in the direction of oscillation is in the range of a resonance length of 0.5 to 1.5 * Lambda / 2 and the length of the clamping element 20 in the direction of oscillation is in the range of a resonance length of 0.5 to 1.5 * Lambda / 2 * X, wherein X is preferably between 1 and 10, e.g.

1.

12. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to one of claims 1, wherein the clamping body 10 includes at least one additional blind hole 22, which is not arranged centrally and extends in its depth to the almost vibration-free point of the clamping body 10, such as at a vibration node where a zero crossing of the longitudinal vibration pattern is recorded in the longitudinal direction and at the almost vibration-free point, the device can be mounted in its position and forces can be absorbed by means of the additional blind hole(s) 22.

13. Device for transforming and transmitting an oscillating motion on at least one mass 30 according to one of claims 1, wherein the clamping body 10 and / or clamping body 20 has at least one transverse bore contains additional media in its blind hole bore or To add or remove through a through-hole.

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