EP3875233B1 - Ultrasound cutting system - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The technical field of the invention is that of ultrasonic cutting, and in particular of food products.

The invention relates more particularly to a device for the ultrasonic cutting of industrial products, in particular agri-food products, by means of a non-resonant blade.

TECHNOLOGICAL BACKGROUND OF THE INVENTION

At a time when food products are more and more often presented pre-sliced in order to facilitate their use or consumption, mastering slicing and cutting operations remains a delicate issue for many products: soft, chewy , sticky, crumbly, hard, heterogeneous, small or even large.

In order to be able to respond to these different problems, new cutting tools and processes are continually being developed. Thus, new techniques have been developed to improve the cutting of certain products, such as cutting by ultrasonic vibrations, for example, by vibrating a blade by resonance.

Ultrasonic cutting is a process using an ultrasonic vibration device setting in motion at high frequency a rigid blade having at least one cutting edge. Thus, the ultrasonic vibrations of the rigid blade, although of moderate amplitude, have such characteristics (speed, acceleration, frequency of vibration) that the object tends not to adhere to the blade and make it possible to increase the power of blade cut. Consequently, this cutting process is particularly suitable for cutting fragile products that cannot tolerate large deformations under the effect of a blade, products rich in fat or sugar and therefore sticky, for cutting into portions of round products, for cutting products of different heights (typically varying between 10 and 120 mm), for cutting very thick products (typically 60 to 200 mm), and again for cutting thin slices (from the order of 2 mm). Thus, ultrasonic cutting makes it possible to meet many cutting objectives and constraints.

However, the use of such an ultrasonic cutting method using a rigid resonant blade has some drawbacks.

Depending on the objects to be cut, it may be useful to regularly sharpen the blade in order to maintain an optimal cutting tool. However, the sharpening operation has the consequence of impacting the vibratory characteristics of the blade and consequently of modifying the resonance frequency of the blade, which generates an imbalance of the electroacoustic assembly. Moreover, this sharpening operation is not always feasible, in particular when the damage to the blade is too great.

Although it is possible to completely modify the shape of the blade, for example by machining, so as to readjust its resonant frequency, this operation is complex, long, costly and penalizing because it must take place as soon as a sharpening of the blade is made and can lead to breakage of the transmitter, of the ultrasonic generator or even of the blade if this readjustment of the resonance frequency of the blade is not correct.

In addition, it is often difficult to repair a broken or cracked blade by reloading material.

In addition, the cutting machine comprising such an ultrasonic device is sized to operate at a given frequency range, which imposes particular dimensional constraints on the blade.

Finally, these cutting machines using ultrasonic devices represent a significant investment and have the disadvantage of being not very versatile since they are generally dimensioned and used for specific applications. Therefore, it may happen that these ultrasonic cutting machines are not suitable for cutting large products. Indeed, the maximum width of a resonant plate is a function of the resonance frequency. The more the frequency increases, the more the width of the blade decreases. Thus, at an ultrasonic frequency of 20 kHz, the maximum length of a resonant blade is around 400 mm for a titanium alloy blade. Therefore, the cutting of large-sized products requires the juxtaposition of several twin blades which complicates the layout and makes the cutting of large products unsuitable because it is too expensive to set up.

To remedy these problems, an ultrasonic cutting device has in particular been proposed using a device for vibrating an inert, ie non-resonant, cutting tool by means of ultrasound using an ultrasonic head. granted. This particular device is described in particular in the patent application EP 3 037 181 A1 .

However, it has been observed that for certain applications, in particular for cutting large, delicate, sticky or adherent food products, this solution, with a non-resonant cutting tool, posed some difficulties and in particular a tendency to adhere to the product cutting tool, which can lead to a loss of material and a degradation of the quality of the cut.

Indeed, the wider a cutting tool, the greater the attenuation of the vibration, which makes it impossible to cut wide products. Added to this are problems linked to the mechanical rigidity of the cutting tool, or even to the ergonomics of such devices.

SUMMARY OF THE INVENTION

In this context, the invention aims to provide a system for cutting industrial products using a non-resonant cutting tool, for cutting food products, which is particularly versatile, easily adaptable according to the applications and dimensions of the products to be cut, having improved cutting qualities compared to ultrasonic cutting devices comprising non-resonant cutting tools of the state of the art.

The invention also aims to propose a system for cutting industrial products from a non-resonant cutting tool having the efficiency advantages of an ultrasonic cutting device using a resonant cutting tool known from the state of the technique, while presenting an economic advantage and an ease of implementation compared to the ultrasonic cutting devices with resonant cutting tool known from the state of the art.

• un émetteur ultrasonore, configuré pour émettre une onde ultrasonore ; et
• un ensemble résonant, couplé à l'émetteur ultrasonore et accordé à l'onde ultrasonore, configuré pour transmettre une vibration selon une direction de propagation ;

l'outil de coupe inerte étant couplé à l'ensemble résonant de manière à vibrer selon un mode de flexion, le système de découpe ultrasonore étant caractérisé en ce qu'il comporte un moyen de mise en rotation configuré pour permettre un mouvement de rotation de l'outil de coupe inerte.One aspect of the invention relates to an ultrasonic cutting system comprising an inert cutting tool and an ultrasonic vibration device, the ultrasonic vibration device comprising:

• an ultrasonic transmitter, configured to emit an ultrasonic wave; And
• a resonant assembly, coupled to the ultrasonic transmitter and tuned to the ultrasonic wave, configured to transmit a vibration along a direction of propagation;

the inert cutting tool being coupled to the resonant assembly so as to vibrate in a bending mode, the ultrasonic cutting system being characterized in that it comprises rotation means configured to allow rotational movement of the inert cutting tool.

The ultrasonic transmitter may also be called "ultrasound transmitter", a term commonly used in the field.

The resonant assembly is said to be tuned to the ultrasonic wave if at least one dimension of each element forming the assembly, in general the length, is equal to a multiple of the half-wavelength of the ultrasonic wave. It is also said in this case that the element is resonant with the ultrasonic wave.

The cutting tool is said to be inert because it is not tuned, or not resonant, to the ultrasonic wave.

The inert cutting tool, coupled to the resonant assembly, is vibrated by the resonant assembly, in vibration in a bending mode. The ultrasonic vibrating device makes it possible to vibrate the inert cutting tool regardless of the geometric configuration of the inert cutting tool.

The inert cutting tool, vibrating at an ultrasonic frequency according to a bending mode, makes it possible to reduce the adhesion of the product during the cutting phase and also to improve the quality of the cut by the non-stick effect.

The bending vibration also makes it easier to separate the product under the edge of the cutting tool.

In addition, the ultrasonic cutting system according to the invention comprises a means for rotating the inert cutting tool making it possible to generating additional shear stress on the product by rotation of said inert cutting tool.

Thus, the cutting system according to the invention makes it possible to improve the cutting power of an inert cutting tool by proposing a rotation of the inert cutting tool, simultaneously with the ultrasonic vibration, generating an anti-adhesion effect.

The cutting system according to the invention using an inert cutting tool advantageously makes it possible to be able to modify the dimensions of the inert cutting tool so as to adjust them to the various formats of the products to be cut. The inert cutting tool can also be sharpened without any major impact on the vibrational properties of the tool.

The non-resonant cutting tool can be interchanged according to the needs and the formats and nature of the products to be cut while keeping the rest of the ultrasonic cutting system. Thus, it is not necessary to provide one ultrasonic cutting system per type of inert cutting tool, which may represent an interest and an economic advantage.

The cutting system according to the invention advantageously combines ultrasonic vibration of the inert cutting tool and rotation of the inert cutting tool so as to mechanically generate an additional shearing force on the products to be cut in such a way as to increase the cutting power of the inert cutting tool.

Cutting power relates the ability to cut a product to the force exerted on the inert cutting tool. The increased cutting power means less force is needed to cut the product.

In addition to the characteristics which have just been mentioned in the preceding paragraphs, the ultrasonic cutting system according to one aspect of the invention may have one or more additional characteristics among the following, considered individually or according to all technically possible combinations.

According to one embodiment of the ultrasonic cutting system, the resonant assembly comprises a first resonant element configured to vibrate according to a first traction/compression mode and a second resonant element configured to vibrate in a second tension/compression mode, the inert cutting tool being positioned between the first resonant element and the second resonant element.

According to one embodiment of the ultrasonic cutting system, the first resonant element is an ultrasonic amplifier.

The ultrasonic amplifier can also be called "booster" in English.

According to an embodiment of the ultrasonic cutting system, the ultrasonic amplifier has an amplification ratio greater than or equal to 1.

The ultrasonic amplifier, resonant with the ultrasonic wave, transmits and amplifies the amplitude of the ultrasonic wave and therefore of the vibration according to the direction of propagation. Thus, the amplitude of vibration in bending of the inert cutting tool is increased.

According to one embodiment of the ultrasonic cutting system, the ultrasonic amplifier has an amplification ratio of less than 1.

The amplitude of vibration of the inert cutting tool is thus reduced, making it possible to reduce the ultrasonic energy transmitted to the product to be cut, in particular in the case where the product is fragile.

According to one embodiment of the ultrasonic cutting system, the second resonant element is a resonant mass.

The resonant mass constitutes a means for connecting the resonant assembly with the inert cutting tool. The resonant mass also makes it possible to optimize the refocusing of the bandwidth of the resonant assembly around the frequency of the ultrasonic wave. Thus, the vibrating efficiency of the inert cutting tool is improved.

According to one embodiment of the ultrasonic cutting system, the ultrasonic transmitter is a piezoelectric transducer generating the ultrasonic wave whose frequency is between 20 kHz and 100 kHz, preferably between 20 kHz and 40 kHz.

According to one embodiment of the ultrasonic cutting system, the ultrasonic cutting system comprises a cutting support, the rotation means being fixed to the cutting support.

The cutting support offers a reaction to the shear stress applied by the inert cutting tool during the cutting phase.

According to one embodiment of the ultrasonic cutting system, the cutting support comprises a protective coating on an upper part, resistant to cutting and to the heat given off by the vibration in flexion of the inert cutting tool.

According to one embodiment of the ultrasonic cutting system, the protective coating of the cutting support is made of silicone or polyurethane with high mechanical strength.

According to one embodiment of the ultrasonic cutting system, the rotation means is positioned close to a first end of the inert cutting tool so as to allow a pivot movement along an axis of rotation.

The pivoting movement provides leverage. The closer the product is positioned to the axis of rotation, the greater the leverage effect. The lever makes it possible to achieve an increased shearing stress which would not be attainable solely by the force of the operator if the inert cutting tool described a vertical translation. Thus the operator will be able to cut hard products, ie products whose shear modulus is high.

According to one embodiment of the ultrasonic cutting system, the ultrasonic device is located on the inert cutting tool close to the axis of rotation.

Thanks to the small distance between the vibrating device and the axis of rotation and the leverage effect, the apparent weight of the inert cutting tool is reduced, facilitating the handling of the inert cutting tool by the 'operator.

According to one embodiment of the ultrasonic cutting system, the ultrasonic device is located on the inert cutting tool at a distance from the axis of rotation.

The weight of the vibrating device intervenes in the leverage effect and makes it possible to obtain a higher shear stress for the inert cutting tool.

According to one embodiment of the ultrasonic cutting system, the axis of rotation is substantially parallel to the direction of propagation of the ultrasonic wave.

According to one embodiment of the ultrasonic cutting system, the rotation means comprises a support part configured to form a pivot connection with a rotation shaft, the rotation means comprising an interface part coupled to the rotation shaft and fixed to the inert cutting tool, the interface part being configured to reflect the bending vibration of the inert cutting tool.

According to one embodiment of the ultrasonic cutting system, the interface part is made of stainless steel.

The inert part, reflecting the vibration of the inert cutting tool, reduces the dissipation of ultrasonic energy into the rotating means, most of the ultrasonic energy thus being employed for the vibration of the inert cutting tool.

According to one embodiment of the ultrasonic cutting system, the rotation means comprises a gripping means, positioned close to a second end of the inert cutting tool.

According to one embodiment of the ultrasonic cutting system, the rotation means comprises a mechanical device, such as a jack or a motor, configured to apply a mechanical torque to the inert cutting tool.

The torque applied by the mechanical device makes it possible to assist the operator in handling the inert cutting tool and thus to achieve higher shearing stresses. The mechanical device can also make it possible to reduce the weight of the inert cutting tool in order to relieve the operator of raising the inert cutting tool at the end of a cutting phase or to position the product.

According to one embodiment of the ultrasonic cutting system, the resonant assembly and the rotation means are removable.

The inert cutting tool can thus be dismantled in order to sharpen or replace it. The inert cutting tool can also be interchanged, in order to adapt to the type of product to be cut.

According to one embodiment of the ultrasonic cutting system, the inert cutting tool comprises a metal blade whose thickness is less than or equal to 10 mm.

According to one embodiment of the ultrasonic cutting system, the blade is made of titanium alloy.

According to one embodiment of the ultrasonic cutting system, the inert cutting tool includes a first cutting edge.

According to an embodiment of the ultrasonic cutting system, the first cutting edge has a first cutting angle less than or equal to 10° and a first thickness of sharpening wire less than or equal to 0.1 mm.

The first cutting edge exerts the shear stress on the product so as to cut the product.

According to one embodiment of the ultrasonic cutting system, the inert cutting tool has a second cutting edge, opposite the first cutting edge.

The first and the second cutting edges, opposite, make it possible to cut the product according to a circular movement back and forth, by cutting the product above and/or below.

According to one embodiment of the ultrasonic cutting system, the second cutting edge has a second cutting angle, less than or equal to 10° and a second thickness of sharpening wire less than or equal to 0.1 mm.

According to one embodiment of the ultrasonic cutting system, the ultrasonic cutting system comprises a means for tensioning the inert cutting tool.

The invention and its various applications will be better understood on reading the following description and on examining the accompanying figures.

BRIEF DESCRIPTION OF FIGURES

• [Fig. 1] montre une représentation schématique, vue de dessus, d'un système de découpe ultrasonore selon un premier mode de réalisation.
• [Fig. 2] montre une représentation schématique partielle, vue de dessus, du système de découpe ultrasonore selon le premier mode de réalisation.
• [Fig. 3] montre une représentation schématique partielle, en coupe, du système de découpe ultrasonore selon le premier mode de réalisation selon un plan I-I.
• [Fig. 4] montre une représentation schématique partielle, vue de dessus, du système de découpe ultrasonore selon le premier mode de réalisation.
• [Fig. 5] montre une représentation schématique, vue de côté, du système de découpe ultrasonore selon le premier mode de réalisation.
• [Fig. 6] montre une représentation schématique, vue de côté, du système de découpe ultrasonore selon le premier mode de réalisation.
• [Fig. 7] montre une représentation schématique, vue de côté, du système de découpe ultrasonore selon un deuxième mode de réalisation.
• [Fig. 8] montre une représentation schématique, vue de côté, du système de découpe ultrasonore selon un troisième mode de réalisation.
• [Fig. 9] montre une représentation schématique, vue de côté, du système de découpe ultrasonore selon un quatrième mode de réalisation.
• [Fig. 10] montre une représentation schématique, vue de côté, du système de découpe ultrasonore selon un cinquième mode de réalisation.

The figures are presented by way of indication and in no way limit the invention.

• [ Fig. 1 ] shows a schematic representation, seen from above, of an ultrasonic cutting system according to a first embodiment.
• [ Fig. 2 ] shows a partial schematic representation, seen from above, of the ultrasonic cutting system according to the first embodiment.
• [ Fig. 3 ] shows a partial schematic representation, in section, of the ultrasonic cutting system according to the first embodiment along a plane II.
• [ Fig. 4 ] shows a partial schematic representation, seen from above, of the ultrasonic cutting system according to the first embodiment.
• [ Fig. 5 ] shows a schematic representation, side view, of the ultrasonic cutting system according to the first embodiment.
• [ Fig. 6 ] shows a schematic representation, side view, of the ultrasonic cutting system according to the first embodiment.
• [ Fig. 7 ] shows a schematic representation, side view, of the ultrasonic cutting system according to a second embodiment.
• [ Fig. 8 ] shows a schematic representation, side view, of the ultrasonic cutting system according to a third embodiment.
• [ Fig. 9 ] shows a schematic representation, side view, of the ultrasonic cutting system according to a fourth embodiment.
• [ Fig. 10 ] shows a schematic representation, side view, of the ultrasonic cutting system according to a fifth embodiment.

DETAILED DESCRIPTION

The figures are presented by way of indication and in no way limit the invention. Unless specified otherwise, the same element appearing in different figures has a single reference.

There figure 1 presents a top view of an ultrasonic cutting system 101 according to a first embodiment according to the invention, intended to produce a cut of a product 1.

For this, the ultrasonic cutting system 101 comprises an inert cutting tool 200 and an ultrasonic vibration device 300.

• un émetteur ultrasonore 310, configuré pour émettre une onde ultrasonore ; et
• un ensemble résonant 320, couplé à l'émetteur ultrasonore 310 et accordé à l'onde ultrasonore, configuré pour transmettre une vibration selon une direction de propagation X et mettre en vibration l'outil de coupe inerte 200.

The ultrasonic vibration device 300 comprises:

• an ultrasonic transmitter 310, configured to emit an ultrasonic wave; And
• a resonant assembly 320, coupled to the ultrasonic transmitter 310 and tuned to the ultrasonic wave, configured to transmit a vibration along a direction of propagation X and to vibrate the inert cutting tool 200.

Inert cutting tool 200 is coupled to resonant assembly 320 to vibrate in a bending mode.

The ultrasonic cutting system 101 further comprises a rotation means 400 configured to allow rotational movement of the inert cutting tool 200 along an axis of rotation Y, substantially parallel to the direction of propagation X.

By substantially, we will mean an angle between the axis of rotation Y and the direction of propagation X comprised between −10° and 10°.

The inert cutting tool 200 to be vibrated is for example a thin metal blade, that is to say having a thickness less than or equal to 10 mm, and advantageously between 0.5 mm and 10 mm.

The inert cutting tool 200 has a length and a height adapted to the product to be cut, preferably a flattened parallelepipedal shape.

The profile of the cutting tool does not influence the vibration in bending, thus the cutting tool can have a single-sided or double-sided profile.

By way of example, the inert cutting tool 200 has a length of between 200 mm and 1000 mm.

By way of example, the inert cutting tool 200 has a height of between 20 mm and 100 mm.

The inert cutting tool 200 is advantageously made of a material having relevant acoustic properties in the implementation of ultrasonic cutting, such as a high modulus of elasticity, for example of titanium alloy. The material may also have physico-chemical properties allowing compatible use in the food industry, such as corrosion resistance and a low transfer rate.

The inert cutting tool 200 has a first longitudinal end 201 and a second longitudinal end 202.

The inert cutting tool 200 also comprises a first flank 210A and a second flank 210B corresponding preferentially to the two largest faces of the inert cutting tool 200. The first and the second flank 210A, 210B are partially connected to one another by a first cutting edge 211, stretching from the first end 201 to the second end 202, intended to make the cut in the product 1.

There picture 2 represents an enlargement of the first embodiment of the ultrasonic cutting system 101 according to the invention, particularly centered on the ultrasonic vibrating device 300. Certain elements are not represented so as to improve the clarity of the picture 2 .

The ultrasonic wave emitted by the ultrasonic transmitter 310, which we will also call "compression wave", is longitudinal, at a fixed frequency, and propagates in the direction of propagation X.

The ultrasonic transmitter 310 is electrically powered by an ultrasonic generator, not shown in the drawings, configured to set the ultrasonic transmitter into acoustic vibration at a frequency in the ultrasonic range.

For example, the ultrasonic transmitter 310 is configured to vibrate at a frequency comprised between 20 kHz and 100 kHz, preferably between 20 kHz and 40 kHz.

The resonant assembly 320 is coupled to the ultrasonic transmitter 310 and is configured to vibrate in resonance with the transmitter at the frequency of the wave of compression and to transmit this compression wave along the direction of propagation X.

The resonant assembly 320 is said to be resonant, or tuned, to the compression wave. Consequently, the resonant assembly 320 has dimensions, advantageously the dimension along the direction of propagation X, which are multiples of the half-wavelength of the compression wave. Thus, a mode of vibration, in tension/compression along the direction of propagation X, is established within the resonant element 320.

According to the first embodiment of the ultrasonic cutting system 101, the resonant element 320 comprises a first resonant element and a second resonant element.

Advantageously, the first resonant element is an ultrasound amplifier 330, also called ultrasound booster or ultrasound booster, configured to amplify the displacement amplitude of the compression wave. An amplification ratio of the ultrasonic amplifier 330 can advantageously be greater than 1 and preferentially of the order of 1.5. The amplification ratio of ultrasonic amplifier 330 can also be less than 1.

The ultrasonic amplifier 330 is for example a part with axial symmetry, made of stainless steel or titanium alloy. In the exemplary embodiment illustrated in figure 1 and at the figure 2 , the ultrasonic amplifier 330 has a length L _B .

The length L _B of the ultrasonic amplifier 330 along the direction of propagation X is preferably equal to the half-length of the compression wave and makes it possible to tune the ultrasonic amplifier 330 to the compression wave. The ultrasonic transmitter 310 and the ultrasonic amplifier 330 are coupled so as to transmit the compression wave coming from the ultrasonic transmitter 310 to the ultrasonic amplifier 330.

Advantageously, the second resonant element is a resonant mass 340. The resonant mass 340 has for example an axial symmetry. In the exemplary embodiment illustrated in figure 1 and the picture 2 , the resonant mass 340 has a length L _M . The resonant mass 340 can for example be made of titanium alloy.

The length L _M of the resonant mass 340 is preferably equal to the half-length of the compression wave and makes it possible to tune the resonant mass 340 to the compression wave.

At a frequency of 20 kHz, the length of the compression wave propagating in a titanium alloy is about 25 cm. In this case, the length L _B of the ultrasonic amplifier 330 and the length L _M of the resonant mass 340 tuned to the compression wave at 20 kHz are multiples of 12.5 cm.

The resonant assembly 320 encloses the inert cutting tool 200 on either side. The resonant assembly 320 makes rigid contact between the ultrasonic amplifier 330 and the resonant mass 340 on a portion of the cutting tool inert 200. The ultrasonic amplifier 330 is in rigid contact on the first side 210A. The resonant mass 340 is in rigid contact on the second flank 210B. The resonant mass 340 is preferentially aligned with the ultrasonic amplifier 330 along the direction of propagation X. Thus the compression wave established within the resonant assembly 320 crosses the portion of the inert cutting tool 200 in the direction of the thickness.

In order to obtain a good quality of contact between the ultrasonic amplifier 330 and the inert cutting tool 200,

The contact surface between amplifier 330 and first flank 210A, also called span, has very good flatness so that the compression wave can be transmitted efficiently, without loss. The range between the amplifier 330 and the first flank 210A can be reduced to a few tens of square millimeters in order to facilitate the transmission of the compression wave. Likewise, the range between the resonant mass 340 and the second flank 210B can also be reduced to a few tens of square millimeters in order to facilitate transmission.

There figure 2 presents an example of displacement d at a given instant within the ultrasonic amplifier 330 and the resonant mass 340 along the direction of propagation X. The displacement d describes a curve taking on the appearance of a sinusoid whose period is equal to the length L _B of the ultrasonic amplifier 330 plus the length L _M of the resonant mass 340. The positive values of the displacement d signify a displacement in the direction of the direction of propagation X and the negative values of the displacement d signify a displacement in the opposite direction to the direction of propagation X. Thus, in the example given, the ultrasonic amplifier 330 is contracted while the resonant mass 340 is expanded. The propagation of the compression wave in the resonant element 320 imposes continuity between the ultrasonic amplifier 330 and the resonant mass 340, vibrating in phase opposition.

The portion of the inert cutting tool 200 enclosed in the center of the resonant assembly 320, is driven by the compression wave and moves according to the repeated tractions and compressions of the ultrasonic amplifier 330 and of the resonant mass 340 According to the example shown in the figure 2 , the portion of the inert cutting tool 200 undergoes a displacement d in the opposite direction to the direction of propagation X. Thus, as a function of time, the portion of the inert cutting tool 200 undergoes a vibration in the direction of X propagation, driven by the compression wave.

The vibration of the portion of the inert cutting tool 200, causes a vibration of the inert cutting tool 200 according to a movement perpendicular to the first and second flanks 210A, 210B. The vibration, which we will refer to as bending mode vibration, propagates through the remainder of the inert cutting tool 200, along the length of the inert cutting tool 200.

The inert cutting tool 200 does not need to be tuned (or resonant) for the flexural mode of vibration to propagate. Thus, the length, the thickness and the height of the inert cutting tool 200 can be adjusted to the dimensions of the product 1 to be cut.

There picture 3 schematically presents a sectional view along a plane II of the first embodiment of the ultrasonic cutting system 101, the plane II being materialized on the figure 5 . There picture 3 presents an enlargement of the first embodiment visible in the picture 2 , particularly centered on the ultrasonic vibrating device 300. However, certain elements are not represented so as to improve the clarity of the description. picture 3 .

The ultrasonic amplifier 330 and the resonant mass 340 are held in contact against the first and second flanks 210A, 210B of the inert cutting tool 200 by means of a first removable attachment 350. The first attachment removable 350 allows the separation of the resonant assembly 320 and the dismantling of the inert cutting tool 200. Thus it is easy to change or remove the inert cutting tool 200.

The first removable attachment 350 is for example a stud, passing through the thickness of the inert cutting tool 200, fixed in two housings each made in the ultrasonic amplifier 330 and the resonant mass 340. The inert cutting tool 200 can have an opening 220 through which the first removable fastener 350 can pass. The first removable attachment 350 can also be attached to the inert cutting tool 200 without the dismantling of the resonant assembly 320 being rendered impossible, the ultrasonic amplifier 330 and the resonant mass 340 being attached to the first removable binding 350.

The manipulation of the inert cutting tool 200, described more precisely below, can be carried out thanks to a flange 430. The flange 430 can for example be fixed on the resonant assembly 320. The flange 430 is advantageously arranged at the level of a vibration node so as to reduce the propagation of the compression wave in the flange 430. The flange 430 can for example comprise a ring 490 resting on a bearing 480 made in the flange 430, minimizing the contact surface between the flange 430 and the resonant assembly 320. The flange 430 can advantageously comprise two parts held by two screws so as to make it removable.

There figure 4 schematically presents, in top view, the first embodiment of the ultrasonic cutting system 101 also presented in the figure 1 . There figure 4 presents in particular an enlargement of the ultrasonic cutting system 101 centered on the axis of rotation Y.

The rotation means 400 comprises a support part 420 and a rotation shaft 460. The support part 420 and the rotation shaft 460 are configured to form a pivot connection through which the axis of rotation Y passes. The inert cutting tool 200 is coupled to the rotation shaft 460, thus making it possible to describe a rotation around the support part 420.

The rotation means 400 comprises an interface part 410. The inert cutting tool 200 is coupled to the rotation shaft 460 by means of the part interface piece 410. The interface piece 410 provides a mechanical connection with the inert cutting tool 200 and also allows the dismantling of the inert cutting tool 200.

According to the example embodiment illustrated in figure 1 , the interface part 410 is placed close to the first end 201 of the inert cutting tool 200. The acoustic impedance and the dimensions of the interface part 410 are chosen so as to favor the reflection of the vibration in bending within the inert cutting tool 200. Thus the bending vibration is not dissipated in the rotating shaft 460 and the support piece 420 or other adjoining elements. For example, the contact surface between the interface part 410 and the inert cutting tool 200 is of the order of a few square centimeters. The interface part 410 can also be made of a material having a high acoustic impedance, such as stainless steel for example. The interface part 410 can also have good thermal resistance so that it does not deform following the heating generated by the friction during the propagation of the vibration in bending. Advantageously, the interface part 410 is made of a material having a melting point above 500°C.

The inert cutting tool 200 can thus carry out a complete or partial rotation around the axis of rotation Y. The complete rotation allows for example a rotary cutting of a plurality of products 1, each product 1 being, for example, arranged around the axis of rotation Y at a distance from the axis of rotation Y less than the length of the inert cutting tool 200.

There figure 5 shows a side view of the first embodiment of the ultrasonic cutting system 101.

In this embodiment, the ultrasonic cutting system 101 notably comprises a cutting support 500, not shown in the preceding figures. The cutting support 500 may comprise a flat surface on which the product 1 is placed, making it possible to support the product 1 during the cutting phase. Advantageously, the cutting support 500 comprises a protective coating on the upper part. The protective coating is resistant to the cutting force and to the heat generated by the vibration in bending of the inert cutting tool 200. The protective coating can for example be made of silicone or be a band of polyurethane with high mechanical strength.

Advantageously, the support part 420 is fixed to the cutting support 500. The term “lowering” will designate the movement which, following the white arrow on the figure 5 , brings the inert cutting tool 200 closer to the cutting support 500. The term “raise” will designate the reverse movement. The cutting edge 211 is advantageously opposite the cutting support 500 so as to penetrate into the product 1 when the inert cutting tool 200 is lowered.

According to one embodiment of the ultrasonic cutting system 101, the ultrasonic cutting system 101 may comprise a gripping means 440 is arranged close to the second end 202 of the inert cutting tool 200, making it possible to put the cutting tool inert section 200 in rotation around the Y axis. The gripping means 440 can be a handle that the operator can grasp. Advantageously, the gripping means 440 is fixed to the flange 430.

The inert cutting tool 200, in rotation around the Y axis, offers a leverage effect making it possible to increase the shearing stress on the product to be cut 1. The leverage effect is in particular characterized by a ratio of the distances between a first distance and a second distance, the ratio of the distances being advantageously strictly greater than 1. The first distance is defined between the axis of rotation Y and the gripping means 440 and the second distance is defined between the axis of rotation Y and the position of the product 1. A shear stress exerted by the cutting edge 211 penetrating into the product 1 is equal to a force exerted by the operator on the gripping means 440 multiplied by the ratio of the distances. Thus, the closer the product is positioned to the axis of rotation Y, the greater the leverage effect.

Advantageously, the first cutting edge 211 has a low cutting angle, less than 10° and a sharpening wire thickness less than or equal to 0.1 mm. The cutting edge 211 can also comprise machined elements increasing the cutting power, such as micro-teeth.

In the example shown in the figure 6 , the ultrasonic cutting system 101 comprises a tensioning means 600 making it possible to exert a mechanical tension F on the inert cutting tool 200, according to the length of the inert cutting tool 200. For example, the mechanical tension F can be applied between the support piece 420 and the flange 430. The mechanical tension F makes it possible to reduce the twisting of the inert cutting tool 200 during the cutting phase. The mechanical tension F can also contribute to reducing the amplitude of bending of the inert cutting tool 200, in particular when the product 1 is fragile and when the amplitude of bending is likely to degrade the surface condition of the sections of the product. 1. The mechanical tension F can also contribute to reducing the mechanical deformation of the inert cutting tool 200 during the cutting of a product 1, improving the quality of the cut. The tensioning means 600 can for example be a C-shaped frame coupled to the support piece 420 and to the flange 430. The tensioning means 600 can also comprise a screw and a knob allowing the adjustment of the mechanical tension F on the inert cutting tool 200.

According to a second embodiment of the ultrasonic cutting system 102 shown in figure 7 , the rotation means 400 comprises a mechanical device 450 configured to apply a mechanical torque to the inert cutting tool 200.

In this second embodiment illustrated in figure 7 , the ultrasonic cutting system 102 is identical to the first exemplary embodiment described previously with the exception of the elements which will be described later.

The mechanical device 450 can be a hydraulic or pneumatic cylinder or an electric motor. The mechanical device 450 can assist the operator or apply the torque alone to the inert cutting tool 200 during the cutting phase. The mechanical device 450 can also facilitate the manipulation of the inert cutting tool 200 by the operator, for example to raise the inert cutting tool 200, once the product 1 has been sliced.

Advantageously, one end of the mechanical device 450 can be placed close to the second end 202 of the inert cutting tool 200, for example on the flange 430. The other end of the mechanical device 450 can be fixed to a rigid element (not shown in the drawings) with respect to the support part 420. Thus, the torque exerted by the mechanical device 450 on the flange 430 makes it possible to lower or raise the inert cutting tool 200.

The mechanical device 450 can, for example, be a pneumatic cylinder or an electric motor.

There figure 8 illustrates a third embodiment of an ultrasonic cutting system 103 according to the invention. In this third exemplary embodiment, the ultrasonic cutting system 103 is identical to the exemplary embodiments described previously with the exception of the elements which will be described subsequently.

The inert cutting tool 200 may include a second cutting edge 212. The second cutting edge 211 is opposed to the first cutting edge 212, partially connecting the first and second flanks 210A, 210B and stretching from the first end 201 to the second end 202 of the inert cutting tool 200. Like the first cutting edge 211, the second cutting edge 212 is intended to carry out the cutting of the product 1.

The addition of the second cutting edge 212 makes it possible to cut the product 1 by lowering the inert cutting tool 200 or by raising the inert cutting tool 200. Another possible use is a cutting of the product 1 according to a movement back and forth, by making a first section of the product 1 by lowering the inert cutting tool 200 then by making a second section of the product 1 by raising the inert cutting tool 200.

The addition of the second cutting edge 212 makes it possible to carry out a through cut of the product 1, without the need to resort to a cutting support 500.

Advantageously, the second cutting edge 212 has a low cutting angle, less than 10° and a sharpening wire thickness less than or equal to 0.1 mm. The cutting edge 212 can also comprise machined elements increasing the cutting power, such as micro-teeth.

A feature common to the embodiments presented in the figure 1 to figure 8 is the arrangement of the ultrasonic vibration device 300. The ultrasonic vibration device 300 is arranged on the inert cutting tool 200 at a distance from the axis of rotation Y. Advantageously, according to the first, second and third embodiment, the ultrasonic vibration device 300 is disposed on the second end 202 of the inert cutting tool 200.

The weight of the ultrasonic vibrator 300 also affects the torque exerted on the inert cutting tool 200 and contributes to the leverage in a positive way.

There figure 9 schematically represents a fourth embodiment of the ultrasonic cutting system 104. In this fourth embodiment, the ultrasonic cutting system 104 is identical to the embodiments described above except for the elements which will be described later.

The ultrasonic vibration device 300 is placed on the inert cutting tool 200 close to the axis of rotation Y. Advantageously, the ultrasonic vibration device 300 is placed on the first end 201 of the inert cutting tool 200. The interface piece 410 is advantageously fixed to the flange 430 which serves as a connecting means between the rotation means 400 and the inert cutting tool 200. The gripping means 440 advantageously remains fixed on the flange 430 so that the bending vibration within the inert cutting tool 200 is not transmitted to the operator.

The distance between the ultrasonic vibration device 300 and the axis of rotation Y being smaller, the operator can handle and reassemble the inert cutting tool 200 more easily.

There figure 10 schematically represents a fifth embodiment of the ultrasonic cutting system 105. In this fifth embodiment, the ultrasonic cutting system 105 is identical to the embodiments described above except for the elements which will be described later.

The support piece 420 is fixed to the cutting support 500 so that the axis of rotation Y is perpendicular to the cutting support 500. Thus the inert cutting tool describes a rotation in a plane parallel to the cutting support 500. This embodiment of the cutting system 105 makes it possible to slice the product 1 along a section parallel to the cutting support 500.

Claims (15)

1. An ultrasonic cutting system (101, 102, 103, 104, 105) including an inert cutting tool (200) and an ultrasound vibrating device (300), the ultrasound vibrating device (300) including:

   - an ultrasonic emitter (310), configured to emit an ultrasonic wave; and

   - a resonant assembly (320), coupled to the ultrasonic emitter (310) and tuned to the ultrasonic wave, configured to transmit a vibration along a propagation direction (X);

   the inert cutting tool (200) being coupled to the resonant assembly (320) so as to vibrate according to a bending mode, the ultrasonic cutting system (101, 102, 103, 104, 105) being characterised in that it includes a rotating means (400) configured to allow a rotation movement of the inert cutting tool (200).
2. The ultrasonic cutting system (101, 102, 103, 104, 105) according to the preceding claim, characterised in that the resonant assembly (320) includes a first resonant element configured to vibrate according to a first tension/compression mode and a second resonant element configured to vibrate according to a second tension/compression mode, the inert cutting tool (200) being positioned between the first resonant element and the second resonant element.
3. The ultrasonic cutting system (101, 102, 103, 104, 105) according to claim 2, characterised in that the first resonant element is an ultrasonic amplifier (330) and in that the second resonant element is a resonant mass (340).
4. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that the ultrasonic emitter (310) is a piezoelectric transducer generating the ultrasonic wave the frequency of which is between 20 kHz and 100 kHz.
5. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that the ultrasonic cutting system (101, 102, 103, 104, 105) comprises a cutting support (500), the rotating means (400) being attached to the cutting support (500).
6. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that the cutting support (500) includes a protective coating on an upper part, resistant to cutting and to heat released by the bending vibration of the inert cutting tool.
7. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of claims 1 to 6, characterised in that the rotating means (400) is positioned in proximity to a first end (201) of the inert cutting tool (200) so as to allow pivot movement about an axis of rotation (Y) and in that the ultrasonic device (300) is located on the inert cutting tool (200) in proximity to the axis of rotation (Y).
8. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of claims 1 to 6, characterised in that the rotating means (400) is positioned in proximity to a first end (201) of the inert cutting tool (200) so as to allow a pivot movement about an axis of rotation (Y) and in that the ultrasonic device (300) is located on the inert cutting tool (200) remote from the axis of rotation (Y).
9. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that the rotating means (400) comprises a support piece (420) configured to make a pivot connection with a rotation shaft (460), the rotating means (400) comprising an interface piece (410) coupled with the rotation shaft (460) and attached to the inert cutting tool (200), the interface piece (410) being configured to reflect the bending vibration of the inert cutting tool (200).
10. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that the rotating means (400) includes a gripping means (440), positioned in proximity to a second end (202) of the inert cutting tool (200).
11. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that the rotating means (400) includes a mechanical device (450), such as a jack or a motor, configured to apply mechanical torque to the inert cutting tool (200).
12. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that the resonant assembly (320) and the rotating means (400) are removable.
13. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that the inert cutting tool (200) includes a metal blade a thickness of which is less than or equal to 10 mm and in that the inert cutting tool (200) includes a first cutting edge (211).
14. The ultrasonic cutting system (101, 102, 103, 104, 105) according to the preceding claim, characterised in that the inert cutting tool (200) includes a second cutting edge (212), opposite the first cutting edge (211).
15. The ultrasonic cutting system (101, 102, 103, 104, 105) according to any of the preceding claims, characterised in that it includes a means (600) for tensioning the inert cutting tool (200).

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