US 3564775 A
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Description (OCR text may contain errors)
/l//ll/ Feb. 23, 1971 RESONANI SONIC CLEANING UTILIZING PARTICULATE MATERIAL IN CONJUNCTION WITH A SONIC REFLECTIVE BAFFLE MEMBER Filed Feb. l0, 1969 BODINE l [lll INVENTOR.
United States Patent O 3,564,775 RESONANT SONIC CLEANING UTILIZING PAR- TICULATE MATERIAL IN CONJUNCTION WITH A SONIC REFLECTIVE BAFFLE MEMBER Albert G. Bodne, 7877 Woodley Ave., Van Nuys, Calif. 91406 Filed Feb. 10, 1969, Ser.y No. 797,751 Int. Cl. B24b 1 9/ 00 U.S. Cl. 51--7 4 Claims ABSTRACT OF THE DISCLOSURE A part to be cleaned is suspended in a particulate medium. The granules of the particulate material are randomly vibrated by means of a resonant vi-bration system, the output of which is coupled to such material through a vibrational member such as a diaphragm. A sonic reflective baffle member is supported in the midst of the granular medium opposite the diaphragm with the part to be cleaned located between the baffle and diaphragm. The baffle functions to concentrate the acoustical energy so as to cause a streaming of the particulate material in the region adjacent to the part. Such energy works on all sides of the part to provide highly effective cleaning and finishing action thereon.
This invention relates to the cleaning and polishing of mechanical parts and more particularly to the utilization of sonic energy to achieve such end results.
In my Pat. No. 3,380,195, issued Apr. 30, 1968, apparatus is described for effectively cleaning and finishing mechanical parts by placing such parts in a container of granular material and then resonantly vibrating the part to be cleaned, thereby effecting the cleaning action.
It has been found that a marked improvement in the cleaning action can be obtained by randomly vibrating the particles of the particulate material as a load on a resonant vibration system and by placing a reflective baffle in the particulate material. The part is located between this baffle and a vibratory member such as a diaphragm through which the resonant energy is coupled to the material. This effectively concentrates the resonant energy in the immediate region of the part and causes an effective streaming of the particulate material around the part in a manner akin to a lboiling action so as to greatly enhance the cleaning action.
It is therefore the principle of each object of this invention to improve the cleaning action of sonically vibrated particulate material by providing a reflective baffle in such material to concentrate the sonic energy in a stream which flows around the surfaces of the part to be cleaned.
Other objects of the invention will become apparent as the description proceeds in connection with the accompanying drawings, of which:
FIG. 1 is an elevational view in cross-section of a first embodiment of the device of the invention; and
FIG. 2 is an elevational Iview in cross-section of the second embodiment of the device of the invention.
It has been found most helpful in analyzing the device of this invention to analogize the acoustically vibrating circuit utilized to an equivalent electrical circuit. Ths sort of approach to analysis is well known to those skilled in the art and is described, for example, in chapter 2 of Sonics by Hueter and Bolt, published in 1955 by John Wiley and Sons. In making such an analogy, force F is equated with electrical voltage E, velocity of vibration u is equated with electrical current i, mechanical compliance Cm is equated with electrical capacitance Ce, mass M is equated with electrical indnctance L,
mechanical resistance (friction) Rm is equated with electrical resistance R and mechanical impedance Z,n is equated with electrical impedance Ze.
Thus, it can be shown that if a member is elastically viIbr-ated by means of an acoustical sinusoidal force F0 sin wt (w being equal to 21r times the frequency of vibration), that 1 F0 sin wt zm-RMLJ (aM-wam)- u (l) Where wM is equal to l/wCm, a resonant condition exists, and the effective mechanical impedance Zm is equal to the mechanical resistance Rm, the reactive impedance components wM and l/wCm cancelling each other out. Under such la resonant condition, velocity of vibration u is at a maximum, power factor is unity, and energy is more efficiently delivered to a load to which the resonant system may be coupled.
It is important to note the significance of the attainment of high acoustical Q in the resonant system being driven, to increase the efciency of the vibration thereof and to provide a maximum amount of power. As for an equivalent electrical circuit, the Q of an acoustically vibrating circuit is defined as the sharpness of resonance thereof and is indicative of the ratio of the energy stored in each vibration cycle to the energy used in each such cycle. Q is mathematically equated to the ratio between wM and Rm. Thus, the effective Q of the vibrating circuit can be maximized to make for highly efficient, highamplitude vibration by minimizing the effect of friction in the circuit and/or maximizing the effect of mass in such circuit.
In considering the significance of the parameters described in connection with Equation 1, it should be kept in mind that the total effective resistance, mass, and compliance in the acoustically vibrating circuit are represented in the equation and that these parameters may be distributed throughout the system rather than being lumped in any one component or portion thereof.
It is also to be noted that orbiting-mass oscillators are utilized in the implementation of the invention that automatically adjust their output frequency and phase to maintain resonance with changes in the characteristics of the load. Thus, in the face of changes in the effective mass and compliance presented by the load with changes in the conditions of the work material as it is sonically excited, the system automatically is maintained in optimum resonant operation by virtue of the lock-in characteristic of lapplicants unique orbiting-mass oscillators. Furthermore in this connection the orbiting-mass oscillator automatically changes not only its frequency but its phase angle and therefore its power factor with changes in the resistive impedance load, to assure optimum efciency of operation at all times. The vibrational output from such orbiting-mass oscillators also tends to be constrained by the resonator to be generated along a controlled predetermined coherent path to provide maximum output along a desired axis.
Briefly described, the device of the invention comprises a container member having a granular material such as a `grit or a slurry contained therein. One wall of the container has a diaphragm member therein which preferably communicates directly with the granular medium. A baffle member is suspended within the granular material opposite the diaphragm. ln other words, the baffle is located Well within the body mass of the -granular material, so that the baffle is surrounded by the granular material and its vibratory energy field. The parts to be cleaned are suspended between the diaphragm and the baffle, in one embodimet of the invention fbeing loosely placed in the granular material, and in another embodiment of the invention being suspended from the baffle member. Sonic energy is generated by means of an orbiting-mass oscillator and coupled to a resonant vibration system including the diaphragm. Vibrational energy is coupled from the diaphragm to cause random vibration of the granular medium, a substantial portion of such energy being reilected by the baille member, thereby resulting in a concentration of the sonic action on the parts to be cleaned.
Referring now to FIG. l, a rst embodiment of the device of the invention is illustrated. Container member 11 has a grit material 12 contained therein, such as for example, coarse sand. In some instances the grit is a slurry containing a liquid. Container 11 may be cylindrical with a cover 13 at the top thereof and elastic diaphragm member 14 forming the bottom thereof. Diaphragm 14 may be of suitable rubber or plastic material. Baille member 15, which may be in the form of a circular plate fabricated of a highly elastic material such as steel, is suspended within granular medium 12 in a position directly opposite diaphragm 14 by means of pillars 16 which extend upwardly from base plate 17. Base plate 17 is ilxedly attached to diaphragm 14 by suitable means, such as, for example, cementing.
The part to be cleaned (18) is held between diaphragm 14 and baille 15 in granular medium 12 by means of clamp 19, which is ilxedly attached to baille 15.
I-Iigh-level sonic energy is provided to diaphragm 14 by means of orbiting-mass oscillator 21, the casing of which is coupled to the diaphragm through pneumatic springs formed by air-illled expansible bladders 23 and 24, bladder 23 being coupled to the diaphragm through plate 27.
Orbiting-mass oscillator 21 is rotatably driven by means of a motor (not shown) Iwhich is coupled to the oscillator through gear box 30 and drive shaft 3'1. The rotor of orbiting-mass oscillator 21 is driven at a speed such as to cause resonant elastic vibration of the vibration system including pneumatic springs 23 and 24, plate member 27, diaphragm 14 and baille 15.
The pneumatic spring mechanism, including bladder members 23 and 24, as driven by oscillator 21, may be of the type described in connection with FIGS. 1 and 2 of my Pat. No. 3,406,782, issued Oct. 22, 1968. The pneumatic spring device, as fully described in this patent, acts as an impedance transformer to assure optimum coupling of sonic energy to the load provided by the granular medium.
With the orbiting-mass oscillator 21 adjusted to a frequency to cause resonant elastic vibration of the vibration system, including diaphragm 14 and baille 15, the granular material 12 is caused to randomly vibrate at a high energy level, such vibration being concentrated on part 18. The granular material tends to boil or stream around the part to effectively clean all the surfaces thereof, the energy being concentrated in the area of the part in a zone formed between the submerged bafile and the diaphragm. The baille causes a vibratory energy gradient within the body of granular material. There thus is a very high energy level flow of the particulate material in the slot formed between the baille and the diaphragm. It is to be noted that in this embodiment of the invention that the diaphragm and baille vibrate together in response to the sonic energy.
Referring now to FIG. 2, a second embodiment of the device of the invention is illustrated. For this embodiment, for the convenience of illustration, the oscillator and pneumatic diaphragm Imechanism are not shown as they may be the same as that illustrated in FIG. l and just described in connection therewith. In this second embodiment, container 11 is similar to that described for the ilrst embodiment and contains granular material 12 therein. In this second embodiment, however, rather than the. parts being iixed in position and suspended from the baille, parts 35 are rather placed in the granular material between baille 15 and diaphragm 14. Batlle 15 is suspended in the granular medium from the top cover 13 of the container member by means of arms 37. In this embodiment thus, baille 15 is not included in the resonant vibrational system and merely acts to reilect sonic energy received thereby through the granular medium. As for the iirst embodiment diaphragm 14 is vibrated as part of a resonant vibration system and causes highlevel random Vibration through the particles of granular medium 12, these particles being caused to boil or ilow through the area bounded by baille member 15 and diaphragm 14.
The device of this invention thus provides highly effective means for concentrating sonic random vibration of particulate material in the region in which parts to be cleaned are located. The sonic activity of the particulate material is enhanced by a streaming action of such material in response to the sonic energy such as to effectively provide cleaning action to all of the surfaces of the parts to be Cleaned.
1. Apparatus for cleaning parts, comprising:
a container member;
particulate material contained within said container member;
a vibratory diaphragm member located in one of the walls of said container member, and in direct communication with said particulate material;
a baille member suspended in said particulate material opposite said diaphragm,
the part to be cleaned being suspended in said particulate material between said baille and said diaphragm;
a resonant vibration system, said system including said diaphragm; and
an orbiting-mass oscillator, the output of said orbitingmass oscillator being coupled to said resonant vibration system;
said orbiting-mass oscillator being driven at a frequency such as to cause resonant elastic vibration of said vibration system,
whereby the individual particles of said material are caused to vibrate randomly to provide a streaming of said particulate material in the area surrounding said part.
2. The apparatus of claim 1 wherein said part is suspended from said baille member, said baille member being supported on said diaphragm and vibrating therewith.
3. The device of claim 1 wherein said baille member is suspended in said particulate material from said container.
4. The device of claim 3 wherein said part is loosely suspended in the particulate material between said bafile and said diaphragm.
References Cited UNITED STATES PATENTS JAMES L, JONES, J R., Primary Examiner