JP2004008905A - Ultrasonic cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic cleaning apparatus in which the soil on a material to be cleaned is effectively removed. <P>SOLUTION: The material 8 to be cleaned is rotated by moving a cleaning arm 13 on which the material 8 is placed in a cleaning vessel 1 (2-4) to change the location in the cleaning vessel 1. The material 8 is further rotated by changing the frequency of ultrasonic wave. in such a case, it is preferable to control the rotating direction and rotating speed of the material 8 by changing the depth of the material 8 in the cleaning vessel 1 (2-4) and the frequency of the ultrasonic wave. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ultrasonic cleaning device. More specifically, the present invention relates to an improvement in an ultrasonic cleaning apparatus that irradiates an object to be cleaned in a cleaning tank with ultrasonic waves to remove dirt.
[0002]
[Prior art]
As a device for automatic cleaning in the process of processing and assembling a work (machine to be cleaned) such as a mechanical part, for example, an arm such as a so-called rotary cleaning device in which a cleaning tank and a drying tank are arranged in a circumferential shape. A cleaning apparatus is used in which a held work is moved from a cleaning tank to a drying tank to perform cleaning and drying.
[0003]
Further, in such a cleaning apparatus, an ultrasonic cleaning apparatus which irradiates a workpiece in a cleaning tank with ultrasonic waves to remove dirt is used. In the ultrasonic cleaning performed here, when ultrasonic waves propagate as compression waves in the liquid, the liquid repeatedly expands and compresses, causing cavitation and interfacial stirring phenomena. It is to remove. In this case, due to the strong acceleration generated in the liquid by the ultrasonic waves and the local impact pressure due to cavitation, dirt that is difficult to remove by simple stirring can be quickly removed.
[0004]
[Problems to be solved by the invention]
However, since the ultrasonic cleaning device used as an automatic cleaning device performs the cleaning operation in a batch process, the manner in which ultrasonic waves are applied to each work (how ultrasonic waves act) is not uniform, In some cases, dirt cannot be effectively removed.
[0005]
Therefore, an object of the present invention is to provide an ultrasonic cleaning apparatus capable of effectively removing dirt on an object to be cleaned.
[0006]
[Means for Solving the Problems]
In order to achieve such an object, the present inventors have studied variously. The ultrasonic wave used in the ultrasonic cleaning device is generally an elastic wave of about 10 kHz or higher, which is higher than the audible frequency. The higher the frequency, the sharper the directivity. In addition, it has a characteristic that it has a large attenuation in the air but is well transmitted in water, and further has features such as a high frequency, a short sound wavelength, and a strong energy. Further, the short wavelength also means that it is easy to form a sound beam into a beam, concentrate on a narrow portion, or create a short pulse. The inventors of the present invention focused on these characteristics of ultrasonic waves and repeated various studies and experiments, and as a result, they found that the object to be cleaned in the cleaning tank irradiated with ultrasonic waves rotates under liquid under certain conditions. Reached.
[0007]
The invention of the present application is based on such knowledge, and the invention according to claim 1 mounts an object to be cleaned in an ultrasonic cleaning apparatus that irradiates ultrasonic waves to an object to be cleaned in a cleaning tank to remove dirt. The object to be cleaned is rotated by moving the cleaning arm in the cleaning tank and changing the position in the cleaning tank.
[0008]
According to a second aspect of the present invention, there is provided an ultrasonic cleaning apparatus for irradiating an ultrasonic wave to an object to be cleaned in a cleaning tank to remove dirt, wherein a cleaning arm on which the object to be cleaned is placed is moved into the cleaning tank. In addition, the object to be cleaned is rotated by changing the frequency of the ultrasonic wave.
[0009]
Further, the invention according to claim 3 is an ultrasonic cleaning apparatus for removing dirt by irradiating an ultrasonic wave to an object to be cleaned in a cleaning tank, wherein the depth and ultrasonic frequency of the object to be cleaned in the cleaning tank are changed. Thus, the rotation direction and the rotation speed of the object to be cleaned are controlled.
[0010]
Since the ultrasonic wave applied to the cleaning tank is not directly applied to the object to be cleaned, and may be irradiated after being reflected on the inner wall of the tank, the distribution in the tank is not necessarily uniform, Even when the ultrasonic wave is continuously being applied to the cleaning tank at a certain level, changing the position of the object to be cleaned in the cleaning tank changes the ratio of the ultrasonic wave irradiated from below or from the surroundings. Changes. Therefore, moving the object to be cleaned in the tank eliminates the bias of the ultrasonic wave applied to the object to be cleaned, and effectively removes dirt such as details or the contact area with the cleaning arm by a complex ultrasonic wave. Can be removed.
[0011]
In addition, by moving the object to be cleaned in the bath to change the degree of contact with the ultrasonic wave, or by appropriately changing the frequency of the ultrasonic wave applied to the object to be cleaned, the cleaning object is cleaned. Can be rotated inside. In this case, the relative flow velocity of the cleaning liquid with respect to the object to be cleaned is increased, and the cleaning effect is promoted by the effect that the cleaning liquid flows into the details and the contact area with the cleaning arm, and the dirt is effectively removed.
[0012]
Further, when the object to be cleaned is rotated in the tank as described above, the rotation direction and the rotation speed of the object to be cleaned can be controlled by changing the depth and the ultrasonic frequency of the object to be cleaned. Thereby, the cleaning effect can be further promoted.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.
[0014]
1 to 5 show one embodiment of the present invention. The ultrasonic cleaning device 48 according to the present invention is a device for irradiating ultrasonic waves to a mechanical part or the like (hereinafter referred to as “work”) 8 as an object to be cleaned in a cleaning tank to remove dirt. The cleaning device 10 is used as a device that undertakes a cleaning operation for removing dirt from the work 8.
[0015]
The cleaning device 10 according to the present embodiment includes a loading device 11 for loading the work 8, cleaning tanks 1 to 4 for cleaning the work 8, drying tanks 5 to 7 for drying the work 8 after cleaning, and a drying tank for drying the work 8. And a cleaning arm 13 for holding the work 8 carried in by the carry-in device 11 and moving the work 8 into the cleaning tanks 1-4 and the drying tanks 5-6. The work 8 can be individually washed (see FIG. 1). In the present embodiment, a partition member 14 is installed between the carry-in device 11 and the carry-out device 12, and the area on the carry-out side partitioned by this (in the present specification, this area is referred to as a "clean area"; (Indicated by reference numeral CA in FIG. 1). The area on the side other than the clean area (general environment area) is indicated by the symbol GA.
[0016]
Further, the cleaning apparatus 10 of the present embodiment is an apparatus including a rotary cleaning tank 9 in which six tanks are circumferentially arranged at equal intervals as shown in FIG. 1, and a cleaning arm 13 disposed at the center thereof. Are provided so as to hold the work 8 and transport it to the tanks 1 to 6 in order. The type of the six tanks depends on the type of the work 8 and whether or not an organic solvent is used as a cleaning agent. For example, in the case of the present embodiment, the first tank is a cleaning tank (hereinafter referred to as “cleaning tank”). Washing tanks for rinsing the second to fourth tanks (hereinafter referred to as “washing tank 2”, “washing tank 3” and “washing tank 4”), and the fifth and sixth tanks An air drying tank (hereinafter referred to as “drying tank 5” and “drying tank 6”) for draining water is used. Further, a vacuum drying tank 7 as a final drying tank is provided near the rotary cleaning tank 9.
[0017]
The cleaning tank 1 is a tank for performing cleaning using, for example, ultrasonic waves, and removes dirt attached to the work 8 immersed in water and a water-based cleaning agent in the tank. A quasi-aqueous detergent, a non-aqueous detergent, or the like may be used as a detergent instead of water and an aqueous detergent. The cleaning tank 2 is a tank for roughly rinsing the work 8 cleaned in the cleaning tank 1 using ultrasonic waves. In the case of the present embodiment, a partition member 14 is provided so as to pass between these two cleaning tanks 1 and 2 and the other tanks 3 to 6 as shown in the figure, and the cleaning tanks 1 and 2 and the other tanks 3 to 6 are provided. And partition. The cleaning tank 3 is a tank for performing secondary rinsing with ultrasonic waves, and the cleaning tank 4 is a tank for performing tertiary rinsing (final rinsing) with ultrasonic waves. The drying tanks 5 and 6 are tanks for drying the work 8 after rinsing by blowing air. Further, the vacuum drying tank 7 is a tank for performing final drying of the work 8 by evacuating the inside of the tank.
[0018]
The carry-in device 11 is a device that transfers the work 8 conveyed to just before the rotary cleaning tank 9 to the cleaning arm 13, and is configured by, for example, a work carry-in robot that holds and moves the work 8 with a pivotable and linearly movable arm. Have been. In the present embodiment, the work 8 is carried into the general environment area from the work entrance 16 by the work transfer pallet 15, and the work 8 is moved to the cleaning tank 1 side by the carry-in device 11. Although not described in detail in the present specification, the work transport pallet 15 is a carriage that travels on the transport rail 16 and transports the work 8, and enters the general environment area from the work entrance 17.
[0019]
The carry-out device 12 is a device that receives the dried work 8 and places it on the work transfer pallet 15 on the carry-out side. For example, like the carry-in device 11, a work that holds and moves the work 8 with a pivotable and linearly movable arm. It consists of a loading robot. Further, the work transport pallet 15 is composed of a carriage that travels on the transport rail 16 and transports the work 8 similarly to the apparatus on the loading side, and carries the work 8 to the outside of the cleaning device 10 through the work outlet 18. In the present embodiment, the work 8 is received from the drying tank 6 by the carrying-out device 12, taken out of the vacuum drying tank 7, and finally dried, and then placed on the work transport pallet 15.
[0020]
The cleaning arm 13 is an arm for individually holding the work 8 carried in and sequentially moving the cleaning tanks 1 to 4 and the drying tanks 5 to 6. In the case of the present embodiment, as shown in FIG. Six cleaning arms 13 having a shape are circumferentially arranged on the arm support shaft 19 at equal intervals. The arm support shaft 19 is a rotatable and vertically movable shaft at the center position of the tanks 1 to 6, and simultaneously raises and lowers the six cleaning arms 13 in each of the tanks 1 to 6, rotates and moves to the next tank. The tip of each cleaning arm 13 may have a shape that allows the work 8 to be directly placed and moved, but in the present embodiment, a work holding jig (not shown) for supporting the bottom surface of the work 8 is used. ) Is a bifurcated support piece 27 to which is attached. Further, each cleaning arm 13 may be configured to be individually attached to the arm support shaft 19, but in the present embodiment, each cleaning arm 13 is formed as a set of two units, It is configured to be detachably attached to the shaft 19 (see FIG. 2). In this case, for example, when cleaning the work 8 of a product related to high-mix low-volume production, it is possible to appropriately replace or remove the unit. Each unit is positioned by a positioning pin 32 on the arm support shaft 19.
[0021]
A cleaning tank 1 in which ultrasonic cleaning is performed (for example, in the present embodiment, all of the cleaning tanks 1 to 4 correspond, but only the cleaning tank 1 is illustrated in FIG. 3) 1 irradiates the workpiece 8 with ultrasonic waves. And an ultrasonic cleaning device 48 for removing dirt. The ultrasonic cleaning device 48 includes an ultrasonic vibrator 49 on the bottom of the cleaning tank 1 as shown in FIG. 3, and is provided so as to irradiate ultrasonic waves toward the work 8 in the tank. For example, the ultrasonic vibrator 49 of the present embodiment is configured by a piezoelectric element fixed to the bottom of the cleaning tank 1 by bolting or bonding. As the piezoelectric element, for example, a vibrator made of BLT (bolted Langevin type vibrator) is used. The bolted Langevin type vibrator is, for example, one in which two perforated piezoelectric ceramics are sandwiched between metal blocks and fastened with bolts and nuts. The ultrasonic oscillator 49 is driven by an ultrasonic oscillator 50 to generate cavitation by ultrasonic waves in the cleaning tank 1 (see FIG. 3).
[0022]
The cleaning tank 1 in which ultrasonic cleaning is performed is generally formed of a stainless steel material. If the cleaning tank 1 is large, it is manufactured by welding, and if it is small, it is manufactured by a spatula (spinning) processing. Further, the cleaning tank 1 of the present embodiment is treated by electropolishing to minimize contamination (metal powder and ions) from the cleaning tank surface. The same applies to the other cleaning tanks 2 to 4.
[0023]
Ultrasonic waves in the ultrasonic cleaning device 48 are suitable for strong dirt cleaning as the frequency is lower, and are more suitable for precise dirt as the frequency is higher. The frequency range is, for example, about 20 to 100 kHz. In the ultrasonic cleaning device 48 of the present embodiment, the ultrasonic waves of 40 kHz are used for each of the cleaning tanks 1 to 3, and the ultrasonic waves of 100 kHz are used for the cleaning tank 4 (see FIGS. 4 and 5). ). However, it is needless to say that the numerical values shown here are only examples and can be changed as appropriate according to the type of the work 8 and the like.
[0024]
Further, the holder of the cleaning arm 13 in the present embodiment is formed so as to have a slight clearance with the work 8 so as not to touch the peripheral surface of the cylindrical work 8 (see FIG. 3). ). The cleaning arm 13 thus formed does not prevent the work 8 submerged in the cleaning liquid in the cleaning tank 1 from rotating by receiving the ultrasonic waves. Further, the cleaning arm 13 raises and lowers the held work 8 inside the cleaning tank 1 to change the work position (depth) A (see FIG. 3), so that the ultrasonic wave irradiated from below or from around can be changed. Changing the irradiation mode, such as changing the ratio or changing the mode of the ultrasonic wave at the position hitting the work 8 such as irradiating the work 8 with the antinode of the ultrasonic wave or irradiating the node. Can be. As described above, according to the ultrasonic cleaning device 48 of the present embodiment, the workpiece 8 can be rotated by moving the cleaning arm 13 in the cleaning tank 1 and changing the position in the cleaning tank 1. In addition, the rotation direction and speed of the work 8 can be controlled by appropriately changing the work position (depth) A. For example, the cleaning effect can be promoted by increasing the relative flow rate of the cleaning liquid with respect to the work 8. In addition to the operation of the cleaning arm 13, the rotation direction and the speed of the work 8 can be further controlled by changing the frequency of the ultrasonic wave emitted from the ultrasonic vibrator 49. In other words, by changing the resonance point on the side of the ultrasonic transducer 49, it is possible to change the frequency to a plurality of frequencies in the same tank, so that the rotation direction and the like of the work 8 can be controlled. The symbol H in FIG. 3 indicates the depth of the cleaning liquid.
[0025]
As described above, the work 8 in the tank to which the ultrasonic wave is irradiated is rotated clockwise or counterclockwise according to the work position (height) A or the horizontal position, and further, the frequency of the irradiated ultrasonic wave. The rotation speed is also slightly changed, but according to the ultrasonic cleaning device 48 of the present embodiment, the depth of the work 8 and the ultrasonic frequency in the cleaning tank 1 (2 to 4) are appropriately changed to change the work. 8 can be controlled in the rotation direction and the rotation speed. For this reason, a higher cleaning effect can be obtained. With respect to the frequency of the ultrasonic wave applied to the work 8, the higher the frequency, the lower the work rotational speed, but the faster the timing of switching between forward and reverse rotation, and conversely, the lower the frequency, the lower the work rotational speed. Since the speed becomes faster, the forward / reverse switching timing becomes slower. Therefore, it is desirable to switch the rotation direction and the rotation speed of the work 8 using this property. Needless to say, the rotation direction and the rotation speed vary depending on the size and shape of the work 8.
[0026]
Each of the tanks constituting the rotary cleaning tank 9, that is, the cleaning tanks 1 to 4, and the drying tanks 5, 6 are tanks that can be attached to and detached from the rotary cleaning tank 9. Therefore, each of the tanks 1 to 6 in the present embodiment has a structure in which the tanks can be easily cleaned in detail in a state where they are detached from the rotary washing tank 9. Each of the tanks 1 to 6 is reproducibly positioned at a predetermined position of the rotary cleaning tank 9 by a positioning pin or the like (not shown). For example, three mounting members 52 and one mounting member 52 per tank fixed on the base plate 51 are provided. It is fixed at this predetermined position by a fixture 22 consisting of three screws to be screwed in (see FIG. 2). The mounting member 52 is, for example, a vertical hexagonal support penetrating through the mounting hole of each of the tanks 1 to 6. When each of the tanks 1 to 6 is detachable as described above, for example, another washing tank is provided in place of the drying tank 5, and the washing content can be changed. Alternatively, one of the cleaning tanks (or drying tanks) may be removed to make an empty space, and a unit for chucking and reversing the work 8 may be incorporated therein to change the direction of the work 8 during the cleaning process. it can.
[0027]
The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, only the rotation direction and the rotation speed of the work 8 in the cleaning tank 1 (2 to 4) are controlled, but combined cleaning with physical cleaning means may be performed. it can. For example, although not particularly shown, by installing a brush or the like in contact with the side surface of the work 8 in the tank with a light resistance, it is possible to automatically perform physical cleaning of the side surface of the work 8 rotating in the tank. .
[0028]
【The invention's effect】
As is apparent from the above description, according to the ultrasonic cleaning apparatus according to the first aspect, the object to be cleaned is moved and rotated in the tank so that the relative flow rate of the cleaning liquid is increased, and the details and the cleaning arm are combined. The cleaning effect is promoted by the action of causing the cleaning liquid to flow into the contact area, and the dirt can be effectively removed.
[0029]
Further, according to the ultrasonic cleaning apparatus of the second aspect, the cleaning arm on which the object to be cleaned is placed is moved into the cleaning tank, and the frequency of the ultrasonic wave is changed to rotate the object to be cleaned, so that the cleaning liquid is removed. The cleaning effect is promoted by the action of increasing the relative flow rate and allowing the cleaning liquid to flow into the details and the contact area with the cleaning arm, thereby effectively removing the dirt.
[0030]
Further, according to the ultrasonic cleaning apparatus of the third aspect, the cleaning effect can be further promoted by controlling the rotation direction and the rotation speed of the object to be cleaned.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a cleaning apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view showing an example of the structure of a cleaning arm, an arm support shaft, and a rotary cleaning tank.
FIG. 3 is a perspective view of an ultrasonic cleaning apparatus showing one embodiment of the present invention.
FIG. 4 is a model diagram of an ultrasonic wave having a frequency of 100 kHz.
FIG. 5 is a model diagram of an ultrasonic wave having a frequency of 40 kHz.
[Explanation of symbols]
1-4 Cleaning tank 8 Work (object to be cleaned)
13 Cleaning arm 48 Ultrasonic cleaning device

Claims (3)

In an ultrasonic cleaning apparatus for irradiating an ultrasonic wave to an object to be cleaned in a cleaning tank to remove dirt, a cleaning arm on which the object to be cleaned is mounted is moved in the cleaning tank, and a position in the cleaning tank is moved. An ultrasonic cleaning apparatus characterized in that the object to be cleaned is rotated by changing the distance. In an ultrasonic cleaning apparatus that removes dirt by irradiating an ultrasonic wave to an object to be cleaned in a cleaning tank, a cleaning arm on which the object to be cleaned is mounted is moved into the cleaning tank, and the frequency of the ultrasonic wave is changed. An ultrasonic cleaning apparatus characterized by rotating the object to be cleaned by changing. In an ultrasonic cleaning apparatus that irradiates an ultrasonic wave to an object to be cleaned in a cleaning tank to remove dirt, the depth and ultrasonic frequency of the object to be cleaned in the cleaning tank are changed to change the ultrasonic frequency of the object to be cleaned. An ultrasonic cleaning apparatus characterized by controlling a rotation direction and a rotation speed.

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