This invention relates generally an article of manufacture and a process for cleaning and inspecting parts exposed to various chemicals during manufacturing.
A variety of newly machined metal and plastic parts must be cleaned during the manufacturing process to remove residues of oil, grease, penetrant and other materials. Typically total immersion systems convey parts through a series of cleaning stations that employ cleaning, agitating and spraying to dislodge chemicals and particles.
Parts to be washed are generally placed into containers and oriented based on the greatest number of parts per container dimensions without regard for other important factors such as penetrant removal. In a typical washing process turbulation moves solution over, under, around and through a part. Manifolds with jets or eductors direct a turbulent liquid flow over a working zone.
One of the functions of industrial parts washing is to remove penetrant used in inspection processes. Fluorescent penetrant inspection (FPI) is a widely applied method used to detect casting and forging defects, cracks, and leaks in new products, and fatigue cracks on in-service components surface breaking defects in non-porous materials such as metals, plastics, or ceramics. FPI is based upon fluid penetration into clean and dry surface-breaking discontinuities through capillary action. Penetrant may be applied to the test component by dipping, spraying, or brushing. After adequate penetration time has been allowed, the excess penetrant is removed and a developer is applied. The developer draws penetrant out of the flaw where an indication becomes visible to an inspector under various lighting conditions.
The effectiveness of the inspection depends on the removal of penetrant prior to application of the developer. The penetrant must be thoroughly removed except for that which reveals any defects in the parts. The contact points between the parts and the container are a problem for penetrant removal. Those part areas or points in contact with the container cannot be effectively spray rinsed without overwashing the non-contact surfaces.
According to an aspect of the present invention a container comprises a plurality of spring-like wires having wave patterns forming a part support that minimize contact points between the container and one or more contained parts when the container is subjected to a vibration causing the wires and the parts to move, thereby eliminating any fixed contact points between a part and the supporting part support.
Another aspect of the invention is a process for removing penetrant from parts comprising: placing one or more parts having a penetrant thereon applied in a container having spring-like wire with wave patterns forming a part support; oscillating the container during a cleaning process thereby compressing and expanding one or more spring-like wires thus exposing part surfaces and removing the penetrant from the parts.
In yet another aspect the invention comprises: a container constructed of stainless steel rods having a wire mesh wave patterns that allow selected parts to flex and reflex in conjunction with an oscillation of the container and a pressured liquid spray on the parts.
The invention is best understood from the following detailed description when read in connection with the accompanying drawing. The various features of the drawings are not specified exhaustively. On the contrary, the various features may be arbitrarily expanded or reduced for clarity. Included in the drawing are the following figures:
a is a perspective view of a parts washing container in accordance with an embodiment of the present invention.
b is a perspective view of a spring-like wire having wave patterns in accordance with an embodiment of the present invention.
c is a perspective view of a spring-like wire having wave patterns in accordance with an embodiment of the present invention.
a-d is a diagram of a parts penetrant application and inspection cycle in accordance with an embodiment of the present invention.
a is a block diagram of a parts washing system in accordance an embodiment of the present invention.
b is a top elevation view of a washing system in accordance with the prior art.
c is a perspective view of a washing system and a container in accordance with an embodiment of the present invention.
a is a front view of a spray chamber spraying parts from top jet sprayers.
b is a front view of the spray chamber spraying parts with middle spray jets.
c is a front view of the spray chamber spraying parts with bottom spray jets.
A shown in
FPI reliability is dependent upon its removal in areas where no defects appear. Therefore a thorough cleaning in every area of a part 120 is essential. The entire surface of a part 120 is cleaned to remove any dirt, paint, oil, grease or any loose scale that could either keep penetrant out of a defect, or cause irrelevant or false indications. The goal of this step is a clean surface where any defects present are open to the surface, dry, and free of contamination.
Referring now to
Referring to
Container 100 is loaded with parts 120 and placed in the washing system 300 where it is typically gently oscillated during a cleaning process cycle. The oscillation means may be provided by the mechanical vibrator or agitator 325 that provides a force (e.g., through a transducer) to the wire through a connection between the wires and a frame member receiving the applied force. Means to create and transmit such forces are well known to those of ordinary skill in the mechanical arts. The period, frequency and amplitude of the agitator 325 vibrations may be controlled by the programmed controller 321 by providing control signals to electromechanical devices (i.e., transducers) also by means well known to those of ordinary skill in the mechanical arts. The oscillating motion causes the spring-like wires 110 having wave patterns to flex and reflex. This contributative motion causes the parts 120 to slightly move thereby allowing complete washing of penetrate at contact points. Such contact points in the prior art washing systems are not capable of being exposed to the washing medium due to the container design and a static processing mode. The current invention by virtue of the spring-like wires 110 and the oscillation working in combination insures that every part of the part 120 surface is exposed to the washing medium.
In
Referring again to
In one embodiment a V-jet nozzle or a full cone of liquid from a plurality of sides, sprays the parts as the container tray oscillates while above the liquid in front of sprays. Each cycle is pre-selected for stroke length and speed during oscillation. Programmed controlled cycle times are used to “fire” each zone for preset exposure times. This provides constantly changing flow patterns to the process and conserves water consumption.
The invention herein also includes a process 500 for washing parts 120 comprising: placing 510 one or more parts 120 having a penetrant thereon applied in container 100 having spring-like wire with wave patterns forming a part support; oscillating 520 the container 100 during a cleaning process thereby compressing and expanding 530 one or more spring-like wires thus exposing part surfaces and removing 540 the penetrant from the parts.
Referring to
As will be noted the basket 610 is moveably supported as the part 611 is subjected to multiple spray exposure in a predetermined sequence as will be explained.
Thus
In
In
As can be ascertained the basket 610 is moved by the chamber apparatus and during each position different nozzles or jets are activated.
The cleaning operation using the special serpentine or wave shaped support wires aids in the thorough cleaning of parts especially those requiring Fluorescent Penetrant Inspection, such as medical prostheses and so on.
It is understood that the only support for the part 612 are the support wires 611. It has been ascertained that by bending the support wires in a serpentine or wave-like configuration, the part bounces or moves from the support wire contact points 611 to expose the contact areas of the part to the spray stream. The wire supports need not be spring-like as, for example, a guitar string or bed spring but are flexible and therefore can move or oscillate. They of course can be flexible or spring-like as well. In any event it is the function of the support wire to minimize the contact area with the part while allowing separation of the contact for a period sufficient to expose the contact area and therefore to enable cleaning of the same.
While the present invention has been described with reference to the illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to those skilled in the art on reference to this description. It is expressly intended that all combinations of those elements that perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated.