• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A method for ultrasonic cleaning of a part (60, 600) which comprises: applying a cleaning solution on a surface (65, 650) of a part (60, 600) to be cleaned; moving (M) a device (10, 10', 100) comprising a sonotrode (4, 4', 40, 50) along said surface (65, 650), maintaining a distance (D) between said surface (65, 650) and the output surface (4e, 4e', 40e, 50e) of the sonotrode (4, 4', 40, 50) closest to said surface (65, 650); applying ultrasonic vibration (V) by the output surface (4e, 4e', 40e, 50e) of the sonotrode (4, 4', 40, 50), wherein the applied ultrasonic vibration (V) has a certain vibration amplitude; as a consequence of said ultrasonic vibration (V), generating a linear homogeneous column (20) of cleaning solution between said output surface (4e, 4e', 40e, 50e) of the sonotrode (4, 4', 40, 50) and said surface (65, 650) and exposing said surface (65, 650) in contact with said linear homogeneous column (20) of cleaning solution to cavitation, thus removing dirt (70) from said surface (65, 650).
    公开号:ES2708149A2
    申请号:ES201890083
    申请日:2017-06-14
    公开日:2019-04-08
    发明作者:De Francisco Oscar Gonzalo；Miranda Jon Ander Sarasua；Bengoetxea Manu Goiogana
    申请人:Fundacion Tekniker；
    IPC主号:
    专利说明:

    [0001]
    [0002]
    [0003]
    [0004] TECHNICAL FIELD
    [0005] The present invention relates to the field of cleaning, both industrial and domestic cleaning. More precisely, it relates to methods and systems for ultrasonic cleaning.
    [0006] STATE OF THE ART
    [0007] An ultrasonic cleaning is a process that uses ultrasound (usually between 20 and 40 kHz) and an appropriate liquid to clean articles. Ultrasonic cleaners are used to clean many different types of objects, including optical parts, surgical instruments, tools, industrial parts and electronic equipment. Ultrasonic cleaning can be used for a wide range of shapes, sizes and workpiece materials. In ultrasonic cleaning, the object to be cleaned is immersed in a metal tank containing a liquid solution (in an aqueous or organic solvent, depending on the application). An ultrasonic generator transducer built into the chamber, or introduced into the liquid, produces ultrasonic waves in the liquid changing in size according to an electrical signal that oscillates at ultrasonic frequency. These elements normally form a resonant circuit. The electrical signal is produced by a high frequency electrical source. Ultrasonic cleaning uses cavitation bubbles induced by high frequency pressure (sound) waves to agitate the liquid. During cavitation, gas bubbles collapse with enormous energy, releasing intense shock waves. When bubbles implode near a surface, such as the surface to be cleaned, an asymmetric collapse can take place, releasing strong jets of water. Both phenomena contribute to eliminate dirt and accelerate chemical dissolution processes. In other words, the agitation produces high forces on the contaminants that adhere to substrates such as metals, plastics, glass, rubber and ceramics. Water or solvents can be used as an appropriate liquid, depending on the type of contamination and the work piece. The use of an appropriate solvent for the article to be cleaned and the type of dirt present usually improve the cleaning effect. Contaminants may include dust, dirt, oil, pigments, rust, grease, algae, fungi, bacteria, lime scale, polishing compounds, agents strippers, fingerprints, hollh, wax and mold release agents, biological dirt such as blood, and the like.
    [0008] An important limitation of conventional ultrasonic cleaners is that the part to be cleaned needs to be completely submerged in the tank containing the liquid. Therefore, conventional ultrasonic cleaners are unviable for large pieces or devices, or for non-separable structures, such as large window panels, building facades, floors, etc.
    [0009] The document JP H06 2183337 A discloses a portable device for ultrasonic cleaning of a piece that does not require the complete immersion of the piece inside a tank filled with cleaning solution. Cleaning is done by blowing water with ultrasonic radiation to the object to be cleaned. The water is contained in a deposit. A puddle of water forms between the ultrasonic device and the surface to be cleaned.
    [0010] Therefore, it is necessary to develop a new method and device for ultrasonic cleaning that overcomes the disadvantages of conventional ones, that is, that they are suitable for ultrasonic cleaning of large pieces or devices and for non-separable structures.
    [0011] DESCRIPTION OF THE INVENTION
    [0012] It is an object of the present invention to provide a new method and device for ultrasonic cleaning that does not require the immersion of the piece to be cleaned inside a tank filled with a liquid. Based on the same principles as conventional ultrasonic cleaning, the method and the device manage to remove dirt from large surfaces (such as metals, bricks, tiles ...) without immersion.
    [0013] In a first aspect of the invention, a method for ultrasonic cleaning of a piece is provided. The method comprises: applying a cleaning solution on a surface of a piece to be cleaned; moving along said surface a device comprising a sonotrode, maintaining a distance between said surface and the outlet surface of the sonotrode closest to said surface; apply ultrasonic vibration on the output surface of the sonotrode, where the applied ultrasonic vibration has a certain amplitude of vibration; as a consequence of said ultrasonic vibration, generate a linear homogenous column of cleaning solution between said sonotrode exit surface and said surface and expose said surface cavitation in contact with said linear homogeneous column of cleaning solution, thus eliminating dirt from said surface.
    [0014] In a particular embodiment, the amplitude of vibration applied to the output surface of the sonotrode depends on the amplitude of vibration on the input surface of said sonotrode and on the relationship between the input cross section of the sonotrode and the output cross section of the sonotrode. sonotrodo
    [0015] The output surface of the sonotrode is preferably curved, the output surface being defined by a radius r, where r = w / 2, w being the width of the cross section of the sonotrode outlet.
    [0016] In a particular embodiment, the amplitude of vibration applied to the output surface of the sonotrode does not exceed a threshold above which said cleaning solution is atomized, said threshold being dependent on the type of cleaning solution and the working frequency.
    [0017] In a particular embodiment, the device moves along said surface maintaining a substantially constant distance between said surface and the outlet surface of the sonotrode closest to said surface.
    [0018] In a particular embodiment, the cleaning solution is applied on the surface to be cleaned prior to the beginning of the operation of the sonotrode, in such a way that a layer of cleaning solution is arranged on said surface.
    [0019] In an alternative embodiment, the cleaning solution is applied on the surface to be cleaned when the sonotrode moves along said surface to be cleaned, in such a way that said linear homogeneous column of cleaning solution is disposed between said surface and the output surface of the sonotrode. The cleaning solution can be supplied externally to the sonotrode by means of a syringe or a spray nozzle; or it can be supplied internally to the sonotrode along a channel disposed within the sonotrode, said channel being designed to bring the cleaning solution to the outlet surface of the sonotrode closest to the surface to be cleaned.
    [0020] The cleaning solution can be reused by the sonotrode absorbing dirt droplets, filtering said droplets of dirt and supplying filtered droplets while the sonotrode moves forward on said surface what needs to be cleaned
    [0021] In a particular embodiment, the cleaning solution is selected from the following group: water and aqueous solutions comprising at least one chemical agent.
    [0022] In a second aspect of the invention, a one-piece ultrasonic cleaning device is provided with the aid of a cleaning solution that must be arranged on a surface of the part. The device comprises: an ultrasonic wave oscillator configured to convert a standard electrical signal operating at 50-60 Hz into electrical energy operating at a frequency comprised within the ultrasonic frequencies; an ultrasonic converter for converting into mechanical vibration said electrical power provided by the ultrasonic wave oscillator; an ultrasonic sonotrode coupled to said ultrasonic converter and configured to generate on its output surface ultrasonic vibration having a certain amplitude of vibration; wherein during the use of the device, said sonotrode is configured to, as a consequence of said ultrasonic vibration on its output surface, generate a homogeneous linear column of cleaning solution between said sonotrode exit surface and said surface and to expose cavitation said surface in contact with said homogeneous linear film of cleaning solution, thus eliminating dirt from said surface.
    [0023] Advantages and additional features of the invention will become apparent from the detailed description that follows and will be set forth particularly in the appended claims.
    [0024] BRIEF DESCRIPTION OF THE DRAWINGS
    [0025] To complete the description and to provide a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate an embodiment of the invention, which should not be construed as restrictive of the scope of the invention, but only as an example of how the invention can be carried out. The drawings comprise the following figures:
    [0026] Figure 1 shows a device for ultrasonic cleaning according to an embodiment of the present invention.
    [0027] Figures 2 (a), 2 (b) and 2 (c) show the behavior of the water under different working conditions during the operation of the method according to the invention.
    [0028] Figure 3 shows a sonotrode or horn according to a particular embodiment of the invention.
    [0029] Figure 4 shows a detailed view of the output surface of the sonotrode of Figure 3. Also shown is an output cross section.
    [0030] Figure 5 shows an ultrasonic horn that is moved along the surface of a piece to be cleaned, according to an embodiment of the ultrasonic cleaning method of the invention.
    [0031] Figure 6 illustrates an ultrasonic horn during operation of the method for ultrasonic cleaning according to the invention.
    [0032] Figure 7 shows a brick, half of whose surface has been satisfactorily cleaned by applying the method of the present invention.
    [0033] DESCRIPTION OF A WAY OF CARRYING OUT THE INVENTION
    [0034] In the present text, the term "includes" and its derivations (such as "understanding", etc.) should not be interpreted in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and define can include elements, stages, etc. additional
    [0035] In the context of the present invention, the term "approximately" and terms of its family (such as "approximate", etc.) should be interpreted as indicative values very close to those that accompany the aforementioned term. That is, a deviation must be accepted within reasonable limits with respect to an exact value, because an expert in the field will understand that said deviation with respect to the indicated values is inevitable due to measurement inaccuracies, etc. The same applies to the terms "to" and "around" and "substantially."
    [0036] The description that follows is not to be taken in a limiting sense but is given solely for the purpose of describing the broad principles of the invention. The following embodiments of the invention will be described by way of example, with reference to the aforementioned drawings showing apparatus and results according to the invention.
    [0037] The ultrasonic cleaning without immersing the piece to be cleaned inside a tank full of liquid can be carried out using the device 10 illustrated in figure 1. The piece to be cleaned (piece 60) is also shown. In the embodiment, the surface 65 to be cleaned of the piece 60 it is represented as substantially planar, but the surface 65 can be single curve; for example, a cylinder. It may have irregularities, such as cavities, pores, etc. The device comprises an ultrasonic wave generator 1 connected to a conventional line voltage (electrical network) 5. The line voltage 5 normally operates at 50-60 Hz, depending on the country. The ultrasonic generator 1 converts the standard electrical signal operating at 50-60 Hz into electrical energy operating at an ultrasonic frequency, that is, above 20,000 cycles per second (20 kHz) approximately. In other words, the ultrasonic wave generator 1 generates high frequency (ultrasonic) electrical energy. The electrical energy provided by the ultrasonic wave generator 1 is converted into an ultrasonic converter (also called an ultrasonic transducer) 2 in mechanical vibration. It is a harmonic vibration whose frequency is the same as that generated by the wave generator 1. The amplitude of the vibration (maximum displacement) is related to the electrical power, and can be amplified mechanically by other components such as intensifiers 3 or sonotrodes 4. The specific characteristics of this mechanical vibration will be given later in the present description. The device 10 may optionally have an intensifier 3 (also called amplifier 3). An intensifier 3 is required in applications that require high power (ie, power higher than that provided by the ultrasonic wave generator 1). Thus, in applications requiring lower power, the intensifier 3 can be eliminated. When present, the intensifier 3 is connected to the ultrasonic converter 2. The intensifier 3 amplifies the ultrasonic vibration introduced from the ultrasonic converter 2. The intensifier 3 also It serves as a mount for a sonotrode or horn 4.
    [0038] The sonotrode or horn 4 is connected to the intensifier 3 and receives the ultrasonic vibration from the intensifier 3. In the absence of an intensifier, the sonotrode 4 is directly connected to the ultrasonic converter 2. The material from which the sonotrode 4 is manufactured can vary with the requirements of power, which in turn depends on the application. Preferably, in applications requiring low power (eg power <400 W) the sonotrode 4 can be made of aluminum, while in applications requiring high power (eg power> 400 W) the sonotrode 4 can be made of titanium.
    [0039] A possible implementation of a sonotrode 4 is illustrated in FIG. 3. The sonotrode or ultrasonic horn 4 includes an end section of the input side or main body 4a having an input surface 4c receiving the ultrasonic vibration from the intensifier 3 (FIG. or from the ultrasonic converter 2, as the case may be), and a section of the outlet side end 4b having an outlet surface 4e (also referred to as the sonotrode tip) disposed spaced apart from the entry surface 4c a distance corresponding to the semi-wavelength (% A) of the ultrasonic vibration which is introduced into the input surface 4c, and which produces the ultrasonic vibration for the liquid disposed on the surface 65. The input surface 4c of the main body or end section on the input side 41 have a certain width W and a length L. The end section of the outlet side 4b is a thinner body 42 having a certain width w, where w <W, and the same length L. The inventors have surprisingly observed that the ultrasonic output vibration, when in contact With liquids disposed on a surface, it causes the liquid to cavitate at high frequency, thus eliminating dirt from the surface 65 of the part 60 on which the liquid is applied. The ultrasonic vibration that is introduced into the ultrasonic sonotrode 4 are longitudinal waves in a direction perpendicular to the outlet surface 4e. The sonotrode 4 also has at least one slotted opening extending through the sonotrode. Preferably it has two slotted openings 43, 44. In a particular embodiment, the slotted openings 43, 44 extend from the end section of the inlet side 41 to the end section of the outlet side 42. Two openings 43 are preferably used, 44 because they help to achieve a homogeneous vibration and, therefore, to achieve a homogeneous cleaning. In order for the sonotrode 4 to be able to clean a surface, the design (geometna) of the exit surface 4e of the sonotrode 4, together with the amplitude of vibration provided by the sonotrode, plays an important role. The outlet surface 4e is preferably curved (arc shape).
    [0040] To clean the surface 65, there must be a liquid interface (liquid droplet) between the surface 65 and the tip of the sonotrode 4e. It is well known that ultrasonic vibration reduces the surface tension of the liquid, which increases the contact surface between the liquid (cleaning solution) and the solid (sonotrode 4 and surface 65). If the contact surface increases, the Kquida interface will be able to retain a larger volume of liquid. The greater the amplitude of the vibration, the more contact surface it will have and in that way, a higher volume of cleaning solution will be retained. To collect as much liquid volume as possible between the tip of the sonotrode 4e and the surface 65, it is desirable that the tip of the sonotrode 4e have as much output surface as possible. Therefore, although the tip of the sonotrode may have a flat shape in a possible embodiment, in a preferred embodiment the sonotrode tip (exit surface 4e) is chosen to be arcuate, i.e., curved, as outlined in FIG. Figure 4. In other words, the tip of the sonotrode preferably has the shape of a half-cylinder having the length L and the radius r. There are two main reasons for this curved exit surface 4. On the one hand, it increases even more the contact surface between the liquid and the sonotrode. Actually, a semi-cylinder (half of a cylinder) gives the optimal ratio between meter and surface. On the other hand, it allows the user to tilt the equipment without changing the relative distance between the tip of the sonotrode 4e and the surface to be cleaned. Other shapes of the sonotrode tip are possible, with those having a large surface being preferred.
    [0041] For a given frequency, depending on the liquid to be disposed between the tip of the sonotrode and the surface to be cleaned, there is a threshold value for which the amplitude of vibration is so high that the drop of liquid becomes unstable and it is atomized. This threshold depends on the physical properties of the liquid. In particular, it depends on the density, viscosity and surface tension of the liquid. For example, in the case that the cleaning solution is tap water, and given a frequency of 20 kHz, this critical threshold is 11 ^ m. In another example, in the case of acetone (cleaning solution), and given the frequency of 20 kHz, this critical threshold is below 3 ^ m. The amplitude of vibration above which the liquid drop is atomized also depends on the frequency applied. In particular, the threshold (the threshold above which the drop is atomized) decreases with the square of the frequency. For example, if the frequency ranges from 20 kHz to 40 kHz (that is, x2), the threshold of the vibration amplitude is divided by 22. In general, if the frequency is multiplied by N (xN), the amplitude threshold of vibration is divided by 2N.
    [0042] These phenomena are illustrated in Figures 2 (a-c). Figure 2 (a) shows a situation in which ultrasound (US) is not applied by the sonotrode 4 'to the liquid layer (cleaning solution) disposed below it. In this case, the conventional liquid droplets can adhere to the outlet surface 4e 'of the sonotrode 4'. Figure 2 (b) shows a situation in which the sonotrode 4 '(and the ultrasonic vibration it produces) has managed to reduce the tension on the liquid below that without atomizing it. When this occurs, the liquid tends to "stick" to the outlet surface of the sonotrode 4e '(in other words, the liquid is drawn to the outlet surface 4e'), generating a large droplet of linear homogeneous liquid 20 (also called homogeneous linear column or static column of Kquido 20). The larger the exit surface 4e 'of the sonotrode 4, the greater the quantity of liquid will form the static column of liquid 20. Any physical object that comes into contact with this drop 20 will be exposed to a very intense cavitation and, therefore, it will be cleaned If there is a relative movement (such as a sweeping motion) between the drop 20 and the dirty porous object, the drop 20 will lose part of its contents, which will remain within the pores. To avoid this problem, the porous surface to be cleaned must be moistened beforehand. Finally, Figure 2 (c) shows a situation in which the ultrasonic vibration produced by the sonotrode 4 'has atomized the liquid disposed below the outlet surface 4e' of the sonotrode. The dirty surface, therefore, is not cleaned. In the examples of Figures 2 (a-c), the liquid is tap water. As already mentioned, the critical threshold of the vibration amplitude applied by the exit surface 4e 'of the sonotrode 4' to which the tap water is not atomized is 11 ^ m given a frequency of 20 kHz. This is why the desired effect (Fig. 2 (b)) occurs when said vibration amplitude is equal to or less than 11 ^ m, while the undesired effect (Fig. 2 (c)) occurs when said amplitude of vibration is above 11 | jm.
    [0043] Referring now to FIGS. 3 and 4, the amplitude of the vibration applied to the output surface 4e of the sonotrode 4 when in use, depends on the amplitude of the vibration at the input surface 4c (provided by the converter) and of the ratio between the input cross section and the output cross section 4f of the sonotrode 4. The input surface 4c is planar, and thus coincides with the input cross section. The input cross section 4c follows the formula L x W. In In any case, in the preferred embodiment illustrated in FIGS. 3 and 4, the outlet surface 4e has the shape of an arc (follows the shape of a half-cylinder (half-cylinder), and therefore does not coincide with an output cross-section 4f. outlet cross section 4f follows the formula wx L. The output surface 4e follows the formula nxrx L, where "r" is the radius of a cylinder having the length L. It should be noted that the tip of the sonotrode (surface of outlet 4e) does not include the area of the two bases of the semi-cylinder, but only the lateral area defined by the half of a cylinder, Figure 4 shows the difference between the exit surface 4e and the exit cross section 4f. the output section 4e is a half cylinder, its radius is determined by the width w of the cross section: r = w / 2. Therefore, the output cross section 4f follows the formula 2 xrx L.
    [0044] As already explained, the inventors have observed that the amplitude of vibration applied on the output surface 4e of the sonotrode 4 is very important, since for each cleaning solution that can be used there is a critical threshold or maximum value of this amplitude of vibration, in such a way that if the amplitude of applied vibration exceeds the threshold associated with each cleaning solution, the cleaning solution will be atomized (Figure 2 (c)) instead of forming a linear homogeneous liquid drop 20 or static column of liquid 20 (figure 2 (b)). The inventors have also observed that when the amplitude of vibration does not exceed said threshold, the larger the exit surface 4e of the sonotrode 4, the greater the amount of static liquid column is maintained between the exit surface 4e and the surface to be cleaned. .
    [0045] To achieve the desired effect (FIG. 2 (b)), the tip of the sonotrode 4e, 4e 'preferably has a semicylindrical shape (half of a cylinder) of surface nxrx L = nxwx L / 2, the corresponding cross section of output 4f being wx L = 2 xrx L, so that, under conditions of nominal power and taking into account the area W x L of the input surface 4c, the vibration amplitude produced by the output surface 4e during the use of the sonotrode does not exceed the critical amplitude for the liquid that is being used (11 ^ m in the case of tap water at 20 kHz). Each converter 2 (figure 1) has a nominal electric power that ensures a given vibration amplitude. The sonotrode 4, 4 'amplifies this vibration proportionally to the relationship between its input cross section 4c and its output cross section 4f. For example, assuming that the cleaning solution is water, if in conditions of nominal power a converter gives an amplitude of vibration of 5.5 microns (5.5 ^ m) and the frequency is 20 kHz, the ratio between the input and output sections of the sonotrode must not exceed 2, since otherwise the output surface of the sonotrode 4e, 4e 'will provide a vibration amplitude greater than 11 microns (11 ^ m) and therefore, the water will be atomized.
    [0046] That is, given a certain cleaning solution (which has specific physical properties) and given the width W of the input cross section 4c of the sonotrode and the width w of the output cross section 4f of the sonotrode (which, in the particular case in which the tip of the sonotrode is arc-shaped, its radius r follows the expression r = 2 xw), there is a threshold of amplitude of vibration above which the ultrasonic vibration produced by the sonotrode 4, 4 'at its output produces the atomization of the liquid arranged below the outlet surface 4e, 4e 'of the sonotrode. As a result, the dirty surface is not cleaned. On the other hand, it is advisable to work with an amplitude of vibration close to said threshold (but below it), because if the amplitude of vibration is much lower than the threshold, the cleaning capacity will be reduced. In short, depending on the output power of the transducer 2, the cleaning solution and the width W of the cross section, there is an optimum sonotrode radius that retains the maximum volume of cleaning solution without atomizing it.
    [0047] The surface 65 to be cleaned can be a substantially simple curvature surface (linear, cylindrical, parabolic ...) so that it can be cleaned by a sweeping movement. The surface 65 must be solid. This surface may have geometrical irregularities, such as cracks, cavities, pores or any other irregularity, such as an ornamental pattern. To clean it properly, the height or depth of the irregularity is preferably smaller than the height of the volume of liquid retained (column 20), as shown for example in Figure 2 (b).
    [0048] The use of the device 10 'for the ultrasonic cleaning of a piece 60 is as follows: the device 10' is swept along the surface 65 of the piece 60 to be cleaned, as illustrated in figure 5. This operation it can be done both manually and by means of automatic devices such as robotic manipulators. To avoid damage (such as scratches) on the tip of the sonotrode and / or on the surface to be cleaned, physical contact between the surface 65 and the tip of the sonotrode 4e. This problem especially affects manual use. Therefore, the device 10 'preferably includes mechanical means, such as wheels, to maintain a certain clearance between the tip 40e of the sonotrode 40 and the cleaning solution disposed on the surface 65 to be cleaned. Said mechanical means are especially recommended during the manual sweeping movement. Figure 6, which will be described in detail below, shows the scanning distance D between the tip of the sonotrode 50e and the surface 650 to be cleaned during scanning of the device 100. The maximum distance (D max ) from the surface 650 to which the sonotrode 50 can sweep is determined by the largest drop or column obtainable from cleaning solution. The maximum distance (D max ) is therefore determined by the maximum volume (amount) of liquid that can be retained between the tip of the sonotrode 50e and the surface. In other words, it depends on the size (length) of the static column of liquid. If the distance D is above the maximum value (D max ), there is no longer any contact between the drop contained between the tip of the sonotrode 50e and the wet surface 650 and therefore the static column is broken. The maximum volume of liquid retained depends on the type of cleaning solution (which has specific physical properties), the material of the sonotrode and the outlet surface 4e of the sonotrode (in the particular embodiment in which the output surface 4e is given by the half a cylinder, the maximum volume of liquid retained depends on the radius r and the length L). In a particular example, in which a sonotrode manufactured from aluminum is used and the sonotrode has a semi-cylindrical exit surface 4e having a radius = 5 mm and a length L = 100 mm, it has been observed that if the distance D exceeds 5 mm, which is actually the largest water drop or column of water obtainable (see column 20 in Figure 2 (b)) under these circumstances, there is no longer any contact between the drop contained between the tip of the sonotrode 50e and the wet surface 650; cleaning will not take place. In other words, the static column breaks. In a particular example, the distance D is selected to be 3 mm so as not to work in boundary conditions.
    [0049] With reference both to FIGS. 5 and 6, between the surface 65, 650 of the piece 60, 600 and the sonotrode 40, 50, a liquid layer or a liquid film (cleaning solution) is applied (not visible). in figure 5). The ultrasonic vibration applied by the sonotrode 40, 50 makes the cleaning solution cavite, releasing strong shock waves and water jets on the surface 65, 650. Both shock waves and water jets remove dirt particles (sand, earth, dust, mold, mud ...) and accelerate the dissolutions (paint, oil, grease ...). The cavitation can penetrate into pores, cracks, cavities or any other pattern present on the surface 65, 650 to be cleaned. In other words, the ultrasonic cavitation power is concentrated on the thin layer of liquid (cleaning solution) when the sonotrode 40, 50 applies ultrasonic vibration to the cleaning solution. Non-limiting examples of cleaning solutions that can be used are water (such as tap water) and aqueous solutions comprising chemical agents, such as detergent, acetone and alcohol. The distance D between the outlet surface 40e, 50e of the end section of the exit side of the sonotrode 40, 50, closer to the surface 65, 650 to be cleaned, is preferably greater than the thickness of the solution layer of cleaning. That is, the outlet surface 40e, 50e of the sonotrode 40, 50 is preferably not in constant contact with the cleaning solution. This distance D, illustrated in FIG. 6, between the outlet surface 50e of the sonotrode 50 and the surface 650 to be cleaned is preferably kept constant throughout the scanning process.
    [0050] The application of a cleaning solution to the surface 65, 650 to be cleaned can be done in different ways. In a particular embodiment, prior to the movement or sweeping of the sonotrode 40, 50 on the surface 65, 650 to be cleaned, a layer of cleaning solution is applied on that surface, such that substantially the entire surface 65, 650 that you have to clean this cover with a layer of liquid. To work in this way, an initial impulse (a single drop of liquid) is necessary. If the ultrasonic vibration is activated, when the drop touches both the liquid layer and the sonotrode tip, a static column of liquid will be generated (a large linear drop, as illustrated in Figure 2 (b)). It does not matter if there is a relative movement between the sonotrode and the liquid layer because the surface tension of the liquid column is so low that it tends to "stick" to both elements. In other words, once the column is formed, it will follow the sweeping motion of the sonotrode. Another way to generate this liquid column is by downward movement of the sonotrode until it comes into contact with the liquid layer.
    [0051] As already mentioned, the sonotrode 4, 40, 50 (in fact, the entire device 10, 10 ', 100) moves on the surface 65, 650, sweeping the surface from a first end 65a to the opposite end 65b, a along the length of the surface 65, 650 to be cleaned, as shown in figure 5. If the surface to be cleaned is wider than the sonotrode width, it will be necessary to sweep the device 10, 10 '. , 100 along the surface 65, 650 as many times as required so that the sonotrode 40, 50 applies ultrasonic vibration on the water arranged over the entire surface to be cleaned.
    [0052] In another particular embodiment, a layer of cleaning solution is not applied covering the entire surface to be cleaned prior to scanning the sonotrode 4, 40, 50 on the surface 65, 650 to be cleaned. Instead, the aforementioned liquid column is constantly regenerated. In this embodiment, a cleaning solution can be provided externally to the sonotrode 4, 40, 50 for example by means of a syringe or a spray nozzle. Alternatively, the cleaning solution can be provided internally to the sonotrode 4, 40, 50 for example along a channel disposed within a sonotrode, designed to carry water to the end section of the outlet side 4b of the sonotrode 4, 40, 50 and more preferably, to the outlet surface 4e, 40e of the sonotrode 4, 40, 50.
    [0053] Figure 6 illustrates the operation of a device 100 for ultrasonic cleaning according to the invention. The ultrasonic wave generator and the intensifier are not shown in figure 6. The piece 600 to be cleaned is also shown. In Figure 6, the arrow M represents the sweeping motion of the device 100. The surface 650 of the piece 600 to be cleaned is cleaned while the device 100 moves forward. The dirt 70 is shown on the surface 650 that has not been cleaned yet. Figure 6 refers to an embodiment in which a layer of cleaning solution on the surface 650 to be cleaned prior to the movement of sonotrode 50 is not provided. Instead, a cleaning solution is provided to the surface 650 as the sonotrode 50 moves forward. The arrow A1 represents the direction of the cleaning solution droplets 80 that are supplied while the device 100 is moving. When the cleaning solution droplets 80 come into contact with the exit surface 50e of the sonotrode 50, the ultrasonic vibration takes place. V, as a consequence from which dirt is removed from the surface 650 of the piece 600. The arrow A2 represents the direction of the dirty droplets 71 which are absorbed by an external forging device while the sonotrode 50 moves forward. In a particular embodiment, in which the cleaning solution is water, the dirty water 71 can be filtered in the device 100, which continuously provides filtered water 80, thereby reusing the water. The same system could be used for any kind of cleaning solution. In this case, the arrow A3 represents schematically the direction of the dirty water (or cleaning solution, in general), which is filtered to be reused. In a particular embodiment, the dirty water 71 is fed back and filtered by means of a hydraulic system that includes a particle filtrate (not shown). In other words, in this embodiment, the water layer is constantly regenerated thanks to the filtering means. In this way, the only water consumed by the device 100 is the water that remains on the clean surface, for example over the pores, if any, arranged on the surface 650 of the piece 600. The water consumption is very low ( just the amount needed to moisten the 650 surface to be cleaned).
    [0054] Below an example is disclosed.
    [0055] An ultrasonic converter operates at 20 kHz and provides vibration that has an altitude of 20 microns (20 ^ m) at its nominal power (1200 W). This output amplitude is too high for the cleaning application. Therefore, it has been reduced to 20 % of the nominal power (4 ^ m of output vibration). A sonotrode having an inlet cross section of 30 x 100 mm2 (W x L) is used. The sonotrode has a curved exit surface, which has a semicylindrical shape defined by a radius r = 5 mm and a length L = 100 mm. The output cross section is therefore 2 xrx L = 10 x 100 mm2. If we divide both values, the ratio is 3, which means that this sonotrode will increase the input amplitude (4 ^ m) by 3, obtaining 12 ^ m in this way. This value is 1 ^ m higher than the maximum vibration amplitude for tap water. However, due to the mechanical damping, it becomes slightly smaller, thus perfectly satisfying the optimum value of 11 ^ m without atomization. If the vibration is activated and water is poured on the tip of the sonotrode, a linear drop of water is generated. The device is swept on the surface to be cleaned at a substantially constant distance D = 3 mm. When this drop of water is put in contact with a dirty surface (a brick in this case, figure 7), cleans it deeply, but only on the surface below the horn tip (100 mm x 10 mm). To clean the entire brick surface, the system sweeps, in this case, at a speed of 10 m / min.
    [0056] In conclusion, the proposed method and device allow to clean pieces of any size using ultrasonic techniques, without submerging the piece in a tank full of water. The method and the device are indicated for the ultrasonic cleaning of pieces having substantially both flat surfaces and of a single curve, having geometrical irregularities, such as cracks, cavities, pores or patterns. Non-limiting examples of applications of the invention are the cleaning of walls that have graffiti and cleaning of bricks or tiles. Among the advantages of the invention, it is that physical contact between the sonotrode and the piece to be cleaned is not required. In addition, the used layer of cleaning solution can be constantly filtered and reused. In fact, on impervious surfaces, such as glass or metal, when a static liquid layer is generated, the consumption of liquid is practically zero because it can be constantly filtered and reused. Ultrasonic waves penetrate pores, cracks or small cavities of the surface to be cleaned. It can be used only with water or with an aqueous solution that includes chemical agents. In this last case, the ultrasonic cavitation drastically accelerates the chemical reactions, dissolving the dirt adhered to the surface to be cleaned. The method and the device can be applied for both industrial and domestic cleaning tasks.
    [0057] On the other hand, the invention is obviously not limited to the specific embodiment (s) described herein, but encompasses any variations that may be considered by any expert in the art (eg, with relation to the choice of materials, dimensions, components, configuration, etc.), within the general scope of the invention as defined in the claims.
    权利要求:
    Claims (12)
    [1]
    1. A method for ultrasonic cleaning of a piece (60, 600), comprising the method:
    - applying a cleaning solution on a surface (65, 650) of a piece (60, 600) to be cleaned;
    - moving (M) a device (10, 10 ', 100) comprising a sonotrode (4, 4', 40, 50) along said surface (65, 650), maintaining a distance (D) between said surface (65, 650) and the exit surface (4e, 4e ', 40e, 50e) of the sonotrode (4, 4', 40, 50) closest to said surface (65, 650);
    - applying ultrasonic vibration (V) on the output surface (4e, 4e ', 40e, 50e) of the sonotrode (4, 4', 40, 50), wherein the ultrasonic vibration (V) has a certain amplitude of vibration;
    the method being characterized in that it comprises:
    - generating a linear homogenous column (20) of cleaning solution between said output surface (4e, 4e ', 40e, 50e) of the sonotrode (4, 4', 40, 50), said output surface being curved (4e, 40e) of the sonotrode (4, 4 ', 40, 50), and said surface (65, 650) by applying a drop of cleaning solution both to the cleaning solution on said surface (65, 650) and to the tip of the sonotrode, or by moving down the sonotrode (4, 4 ', 40, 50) until it is brought into contact with the cleaning solution on said surface (65, 650), and exposing said surface to cavitation (65, 650) in contact with said linear homogeneous column (20) of cleaning solution, thus eliminating dirt (70) from said surface (65, 650).
    [2]
    2. The method of claim 1 wherein said amplitude of vibration applied to the output surface (4e, 4e ', 40e, 50e) of the sonotrode (4, 4', 40, 50) depends on the amplitude of vibration in the entrance surface (4c) of said sonotrode (4, 4 ', 40, 50) and the relation between the input cross section (4c) of the sonotrode (4, 4', 40, 50) and the cross section of output (4f) of the sonotrode (4, 4 ', 40, 50).
    [3]
    The method of claim 2, wherein the curved exit surface (4e, 40e) of the sonotrode (4, 4 ', 40, 50) is defined by a radius r, wherein r = w / 2, w being the width of the output cross section (4f) of the sonotrode (4, 4 ', 40, 50).
    [4]
    4. The method of any preceding claim, wherein said amplitude of vibration applied to the output surface (4e, 4e ', 40e, 50e) of the sonotrode (4, 4', 40, 50) does not exceed a threshold by on top of which said cleaning solution is atomized, said threshold being dependent on the type of cleaning solution and the working frequency.
    [5]
    The method of any preceding claim, wherein said device (10, 100) moves along said surface (65, 650) maintaining a substantially constant distance (D) between said surface (65, 650) and the exit surface (4e, 40e) of the sonotrode (4, 40) closest to said surface (65, 650).
    [6]
    6. The method of any preceding claim, wherein said cleaning solution is applied on the surface (65, 650) that must be cleaned prior to the start of operation of the sonotrode (4, 4 ', 40, 50), such so that a layer of cleaning solution is disposed on said surface (65, 650).
    [7]
    7. The method of any preceding claim from 1 to 5, wherein said cleaning solution is applied on the surface (65, 650) to be cleaned as the sonotrode moves (4, 4 ', 40, 50). ) along said surface (65, 650) to be cleaned, in such a way that said linear homogeneous column (20) of cleaning solution is disposed between said surface (65, 650) and the exit surface (4e, 4e ', 40e, 50e) of the sonotrode (4, 4', 40, 50).
    [8]
    The method of claim 7, wherein said cleaning solution is supplied externally to the sonotrode (4, 4 ', 40, 50) by means of a syringe or spray nozzle.
    [9]
    The method of claim 7, wherein said cleaning solution is supplied internally to the sonotrode (4, 4 ', 40, 50) by means of a channel disposed within the sonotrode (4, 4', 40, 50) , said channel being designed for take the cleaning solution to the exit surface (4e, 4e ', 40e, 50e) of the sonotrode (4, 4', 40, 50) closest to the surface (65, 650) to be cleaned.
    [10]
    The method of any of the preceding claims from 7 to 9, wherein said cleaning solution is reused by the sonotrode (50) by absorbing (A2) dirty droplets (71), filtering (A3) said dirty droplets and supplying (A1) filtered droplets (80) while the sonotrode (50) moves forward on said surface (65, 650) to be cleaned.
    [11]
    The method of any preceding claim, wherein said cleaning solution is selected from the following group: water and aqueous solutions comprising at least one chemical agent.
    [12]
    12. A device (10, 10 ', 100) for ultrasonic cleaning of a piece (60, 600), with the help of a cleaning solution to be arranged on a surface (65, 650) of said piece (60, 600). ), said device (10, 10 ', 100) comprising:
    - an ultrasonic wave oscillator (1) configured to convert a standard electrical signal operating at 50-60 Hz into electrical energy operating at a frequency comprised within the ultrasonic frequencies;
    - an ultrasonic converter (2, 20) for converting said electric energy provided by the ultrasonic wave oscillator (1) into mechanical vibration;
    - an ultrasonic sonotrode (4, 4 ', 40, 50) coupled to said ultrasonic converter (2, 20) and configured to generate on its output surface (4e, 4e', 40e, 50e) ultrasonic vibrations (V) having a certain amplitude of vibration, wherein the exit surface (4e, 40e) of the sonotrode (4, 4 ', 40, 50) is curved;
    wherein during the use of the device (10, 10 ', 100), said sonotrode (4, 4', 40, 50) is configured to generate a linear homogenous column of cleaning solution between said output surface (4e, 4e) ', 40e, 50e) of the sonotrode (4, 4', 40, 50) and said surface (65, 650) by either applying a drop of cleaning solution to both the cleaning solution on said surface (65, 650) as to the tip of the sonotrode or moving down the sonotrode (4, 4 ', 40, 50) until it is brought into contact with the cleaning solution on said surface (65, 650) , and exposing to cavitation said surface (65, 650) in contact with said homogeneous linear film of cleaning solution, thereby eliminating dirt (70) from said surface (65, 650).
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    同族专利:
    公开号 | 公开日
    ES2708149R1|2019-04-11|
    ES2708149B2|2021-05-14|
    WO2017220420A1|2017-12-28|
    EP3260209A1|2017-12-27|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4439847A|1981-12-21|1984-03-27|The Stoneleigh Trust|High efficiency broadband directional sonar transducer|
    US4694699A|1986-06-30|1987-09-22|Universite De Sherbrooke|Acoustic microscopy|
    JPH06218337A|1993-01-25|1994-08-09|Kaijo Corp|Ultrasonic cleaning machine|
    SE524231C2|2002-02-12|2004-07-13|Tetra Laval Holdings & Finance|Ultrasonic Horn|
    US6845778B2|2002-03-29|2005-01-25|Lam Research Corporation|In-situ local heating using megasonic transducer resonator|
    JP5446584B2|2009-08-20|2014-03-19|富士通株式会社|Cleaning system and cleaning method|
    WO2014129167A1|2013-02-21|2014-08-28|凸版印刷株式会社|Coated film removing apparatus|CN111715612A|2019-03-21|2020-09-29|重庆方正高密电子有限公司|Cleaning device|
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    优先权:
    申请号 | 申请日 | 专利标题
    EP16382293.5A|EP3260209A1|2016-06-23|2016-06-23|Method and device for ultrasonic cleaning|
    PCT/EP2017/064645|WO2017220420A1|2016-06-23|2017-06-14|Method and device for ultrasonic cleaning|
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