Patent Application
20070158888
The present invention relates to isolators, and, in particular, isolators useful in automotive applications, to reduce undesirable contact or impact, and/or its associated noise, between various parts or components of the automotive vehicle.
Isolators are useful in a number of applications, especially where vibration or other movement might occur between two devices, parts or portions of devices or parts. Such vibration or movement can cause both contact issues as well as noise issues related to undesired contact or impact Particularly in assemblies where devices or parts must be mounted together or in close proximity to one another, undesirable contact may occur, and isolators have, as one of their functions, the function of preventing or modulating undesirable contact in such a manner that it is either becomes a non-harmful contact, or even an advantageous one.
Isolation can occur in numerous stages or steps. Multi-stage isolation can be achieved in the same isolator or isolator pad by over-molding different density materials or by thinning specific webs called ‘thinning webs’ between mounting surfaces.
Isolators can be made from elastic material, and, thus, can have levels of stiffness. An isolator, for example, may be of a single stiffness. Isolators may also be made via various processes. An isolator, for example, may be made from a single molded process.
Isolators have been found to be particularly useful in automotive applications. One such application is that of heat exchanger assembles, particularly where such assemblies are mounted to vehicles, and, in particular, automotive vehicles. In such automotive applications, heat exchanger assemblies are often mounted either as a single unit or as a group in, for example, parts or components of a cooling module assembly.
In general automotive applications, vibration and other movements are felt throughout various areas of the automobile, particularly when the automobile is moving in the lateral or vertical sense. Otherwise stated, a motor vehicle, when either moving forward or backward, or when being transported in numerous directions, or even when idling with the motor operation, is subject to movement that may cause various parts or features of the automobile to contact one another. A heat exchanger assembly, and/or its component/parts, may contact or collide with other parts, components or portions of other assemblies or the frame of the automobile, and lead to potential damage to either the heat exchanger, the heat exchanger assembly, or other parts of the vehicle itself. This can be particularly disturbing due to the current trend of reducing the amount of materials and the type of materials used in component parts both of the automobile itself and the heat exchanger in particular. In the case of heat exchangers, for example, materials can account for more than half of the total cost of the exchanger. Such exchangers are, therefore, being made of materials that are of the minimal thickness possible—however, such thin metal and plastic materials often cannot withstand the impact stress which occurs through a motorized vehicle frame that occurs while driving on rough roads or making sudden stops or sharp turns. Isolators, correctly designed, reduce potential damage to the heat exchanger assembly under impact or contact stress conditions.
In any system where movement may cause undesired impact or contact between parts or devices, three elements are often considered. For example, in heat exchanger mounting and isolation systems, vibration issues, such as Noise, Vibration & Harshness (NVH), occur. This movement can be described as “low excursion/high frequency” vibration that produces “airborne sound” This movement can be described as medium inertia/medium frequency vibration. If the mounting has a relatively stiff vehicle component, it can receive and transmit vibrations that can annoy the quiet and comfort of the passengers in and around the vehicle. This movement can be described as ‘high inertia/low frequency impact’ often associated with “rough road” driving conditions. For example, severe differences could occur under conditions such as driving across a shallow hole or sharp turning of a vehicle at sufficient speed to cause damage to the heat exchanger assemblies. In such systems, one of the isolator's purposes is to allow for an attachment that is not too rigid, or even what might be called a ‘loose’ attachment of a heat exchanger assembly to a vehicle mounting frame. An isolator can also assist in dampening the differential movement between the heat exchangers and the vehicle, and thereby, help avoid undesired impact or contact between the heat exchanger assembly and the rest of the vehicle and/or its mounting or mounting frame.
Solutions to noise and vibration issues in various applications exist in the prior art. For example, soft isolators composed of lower durometer material (e.g. less than 30 durometer materials) have been used to eliminate noise transmission. The present the problem, however, that they can fail over time and are more often than not, unable to absorb high impact energy such as that experienced while driving an automotive vehicle on unpaved or otherwise rough roads. Other solutions to noise issues, such as the use of vertical standing ribs, are described U.S. Pat. No. 5,960,673, issued Oct. 5, 1999, to Eaton et al.,that can absorb initial noise transmission. However, this solution also has the disadvantage that the individual ribs can wear away prematurely because the high energy present is not adequately distributed over the full area of the isolator surface.
Stiff isolators, such as those described in U.S. Pat. No. 6,540,216 B2, issued Apr. 1, 2003, to Tousi et al., U.S. Pat. No. 4,858,866, issued Aug. 22, 1989, to Werner, can absorb impact shock between components by keeping the components separated, but, both noise and vibration are more easily transmitted through the stiff rubber members. Webbed isolators, such as those described in U.S. Pat. No. 6,722,641, issued Apr. 20, 2004, to Yamada et al., are described as having various thicknesses of rubber webs and/or plastic or metal insert members, and rigidly support the mount in or on each side of the isolator mounting face. The isolator uses a different thickness of rubber web to vary its stiffness. With this solution, when parts move closer together relative to each other, resistance increases. However, this sort of assembly also generally costs more than other isolators or isolator systems.
Loosely fitting isolators with, for example, an air gap at the mounting face, are show in U.S. Pat. No. 6,540,216 B2 issued on Apr. 1, 2003 to Tousi et al., wherein such isolators can be seen as useful in absorbing some misalignment of parts and/or undesirable vibration. However, such a gap can cause damaging impact from unrestricted acceleration across the gap when used between a heat exchanger and some adjacent components.
Dual density isolators, having two different density materials exist. Dual stage webbed isolators, for example, those using metal or plastic inserts, would normally require separate placement of the inserts and lead to increased piece cost and mold cycle time. Webbed isolators themselves can be too stiff and transmit too much vibration to be useful in many automotive applications. For example, when the isolator is softened to reduce vibration transmission, the isolators can fail prematurely, especially when the isolators have a thinned area of a web which can be stretched or compressed beyond their normal elastic limits (usually during harsh movements with high acceleration).
A single stage isolator can either solve one of the three problems described above, or be compromised to partially solve two of the problems, but cannot solve, in one unit, the above limitations. Likewise, a dual stage isolator, with different densities, requires a more expensive material process having two different density materials injected into the injection mold.
Most of the current technologies which have isolators that can absorb noise vibration and harshness has either or both reduced endurance or increased manufacturing costs. Low durometer (stiffness) isolator material can not be used to achieve high durometer (stiffness) requirement. Low durometer (stiffness) isolator material wear much quicker than high durometer (stiffness) isolator material. Wear can lead to uneven isolator compression and these designs will wear quickly.
The advantage of aspects of the present invention that he provide for isolator designs that are less expensive than traditional isolators and they absorb high frequency noise vibration, medium vibration and low frequency high inertia harsh vibration, without exhorbitant increase in production cost or sacrificing overall endurance of the isolator while various aspects of the present invention provide for use of higher durometer (stiffness) isolator to achieve low durometer and high duromater isolator requirements.
Isolators of various types are illustrated by two provisional applications filed Nov. 30, 2005, U.S. patent application Ser. Nos. 60/740,767 and 60/740,983, Daniel Domen, Peter Chen and Mohammed Ansari, which are hereby incorporated by reference in their entireties.
The present invention relates, in various aspects, to isolator assemblies and isolators between separate parts or components, and, particularly, multi stage isolators, especially isolators useful in automotive applications.
The present invention, in its various aspects, avoids the problems of the prior art, especially due related to undesired contact or impact scenarios found in assembly of parts in automotive applications. In various aspects of the present invention, airborne noise, generated by contact or acoustic harmonic oscillations and/or movement, impact, is greatly reduced. By initially softly holding parts or components apart by an isolator, the movement of the oscillating component is slowed, in various aspects of the present invention, by an isolator having a tubular section—the initial “soft contact” is made to slow the resonant movement and alter movement towards a non-acoustic resonant frequency. In various aspects of the present invention, the isolator has at least two portions, with at least one portion having walls with an internal space or hollow portion. The hollow portion flexes as a wall or part of wall bend to flat. The wall or part of wall in the area of the hollow of the hollow portion collapses into the hollow, and the wall or part of wall previously in the hollow area is folded over or displaced near the rest of the isolator wall so that the folded over or displaced walls or parts of wall, together form an approximate equal to the thickness of the rest of the wall outside of the hollow.
In the automotive industry, heat exchange modules such as cooling modules, (modules assembled with the intention of using for heat transfer applications), may be assembled to or fixed to the automotive vehicle body, and, often, to the vehicle frame. The cooling modules should be assembled to the vehicle frame on a consistent basis, to have as closely as possible, a ‘perfect’ alignment. Each heat exchanger component or part of the module, has a fit with its adjacent or corresponding non-heat exchanger component or part, for example, need to be adjusted based on the varies relative positioning in space in the vehicle of the component or part. The fit can loose in many cases, or the components themselves can be grounded or snugly fit to each other through an isolator. Grounding transmits the vibration energy more or less in a direct manner to other components in the vehicle. Loose fitting assemblies can accelerate transfer of inappropriate energy, and, in particular, movement and later noise energy, during harsh driving conditions. Higher energy levels can damage both not only the cooling module, but also any adjacent components to either the module or the other parts of the automobile, or to the isolators between the cooling module, for example, and the adjacent components of the automobile.
The multi-stage isolator, of various aspects of the present invention, can be used in almost any vehicle or mobile system that requires noise isolation, component suspension to reduce transmitted vibration or more severe harshness conditions, for example as a vehicle or mobile system multi-portion isolator. For example, a mounting frame or a mounting frame vehicle component, an engine drive train component, a heat exchanger drive train component, or other components of an automobile vehicle, which are adjacent to one another, or otherwise contact one another, can be separated by use of isolators, in accordance with an aspect of the present invention.
Aspects of the present invention include use of isolator and component assemblies for use, for example, for suspension during shipment of more fragile assemblies packaged in larger container frames, such as assemblies in box containers used for train, plane or boat shipments.
The present invention, in various aspects, provides for an isolator that is made from a single durometer elastic material compound that can absorb lighter vibrations and also resist heavier impact load. In various embodiments of the present invention, the isolator is made of an elastic or elastomeric or rubber or rubber like material made of a single stiffness, and, therefore, in various embodiments from a single process.
In aspects of the present invention, a single higher durometer (stiffness) is used to provide adequate isolation at different level of load. A multi stage isolator is provided having a hollow area design within the isolator. Since higher durometer isolator material can resist wear, a simple and structurally stable design is possible. In various embodiments of the present invention, by providing for an isolator with a collapsable hollow area or “hollow”, after the hollow area collapses, the isolator is evenly compressed and will wear evenly.
Various aspects of the present invention provide for use of higher durometer (stiffness) isolator material to achieve low durometer and high durometer isolator requirements. Instead of using different materials, low stiffness requirement can be achieved by varying the size, the oval shapes of the hollow area.
The present invention, in its various aspects, allows for the production of “low cost” isolators that can be made from single durometer material. The present invention, under conditions of load, provides for an isolator that can flex under light load and/or flatten, and, in aspects of the invention, flatten to a uniform thickness, under heavier loading. The present invention, in various aspects, therefore, provides for an isolator of a single durometer material, and, in various embodiments, an elastic or elastomeric or rubber or rubber like material, that can go through at least two load resisting stages, depending on the loading due to contact (initial or light contact or impact ‘low inertia’), or later heavy contact or impact (‘heavy inertia’) that the isolator and part or component endure.
In various embodiments of the present invention, an isolator having two or more portions is provided, the number of portion based on desired isolation function. For example, when an isolator, in accordance with an aspect of the present invention, is subjected to load of varying intensity, it, adjusts to each load depending on intensity, in a different manner. For example, the different physical design characteristics of each portion of the isolator respond to produce a different effect (for example one portion of an isolator can flex (flexing portion) while another portion compresses (compressing portion) under load). The isolator, in aspects of the present invention, may also have one or more slit(s) that divide the walls of the first stage flexing portion to further enhance the initial flexibility of the first (flexion or ‘deflection’) stage and to ‘soften’ the initial deflection. The multiple stages of dampening of the isolator is provided by forming geometric shapes with hollow areas that can flex or deflect initially, and, thereafter be deflected, to flat and compressed in a second compression stage.
In various embodiments of the present invention, the isolator comprises at least two portions, a flexing portion (first portion) and a compression portion (second portion). The walls around the hollow areas in the first portion can be described as having a deflecting stage where the elastic material wall around the geometric hollow areas bends inward to fill in the space or area (‘hollow’) thereby allowing for suspension, for example, of a heat exchanger component relative a mounting frame in a motorized vehicle and, eventual absorption of vibration generated differential movement between the heat exchanger assembly and the mounting frame. In various aspects of the present invention, a multiple stage isolator is provided wherein deflected walls fill in or ‘close’ the space or area (‘hollow’) to form a uniform thickness wall with the remainder of the isolator to evenly distribute the harsh load energies over the area of contact of the wall sections.
Aspects of the present invention have an isolator, made of a uniform density material, having hollow portions shaped in an approximately tubular cross section. The connecting wall portions surrounding the hollow portions are of a thickness of approximately one-half (½) times the thickness of the remaining connecting wall portions thickness, such that, for example, if a tubular wall portion is deflected until it is more or less flat or reduced in overall area to flat, it doubles in thickness so that the overall thickness, in spite of the light load now applied to the isolator, is approximately equal to the ‘normal’ wall non-deflected thickness. The isolator wall, in the end of a first deflection stage, can have further load applied which leads to a second compression or compressing stage, where the uniform ‘doubled’ first portion wall works in unison with the full thickness wall second portion wall of the isolator to provide for an approximately even distribution of high inertia impact load. The approximately uniform full wall thickness not only improves the ability to absorb during high loading, it also improves the life of the isolator itself.
In various embodiments of the present invention the rate of allowed movement inward between the opposing component surfaces, relative to rate of increased load, is increased dramatically between the collapsing portion of the hollow section and the fully flattened constant thickness of the isolator. This rate change dampens the frequency/short excursion noise and vibration that normally would occur during the first deflection portion of movement.
The geometrical shape of the cross section around the hollow has an effect on the deflection rate. For example, as the base of the hollow wall at the connecting normal wall end approaches normal to vertical adjacent to the contact surface, the resistance increases as loads increase from light to heavier; the load requirement increases in order to deflect the wall a given distance toward the flat position.
In aspects of the present invention having at least one deflecting portion and at least one compression portion, the compression portion of the isolator provides for a low frequency/high inertia dampening during harsh conditions. In aspects of the present invention, having an isolator with an approximate tubular cross section, with an approximate wall thickness of one-half (½) times the normal constant wall thickness as when entering the compressive mode, the wall portion is of a constant thickness and is non-perpendicular to the contacting surface. In more particular aspects of the present invention involving an assembly of parts or components and at least one isolator for example, the isolator with tubular wall cross section has a wall that is generally not parallel to the contact surfaces of the opposing parts or components, e.g. a heat exchanger assembly and the mounting frame, and is generally not normal to the direction of inertia load being applied by the opposing parts.
In aspects of the present invention, the generally tubular shaped cross section area of the isolator provides a lower rate resistance to absorb noise and vibration transmission from, for example, in a heat exchanger assembly to a mounting frame in a motorized vehicle. The area at each end of the non-perpendicular wall is parallel to the contact area and connected to the normal wall such an “eyelet” shaped hollow between the outer wall. In particular aspects of the present invention, the thickness of the contact area is approximately the same as the wall thickness of the normal wall section.
As stated herein, the total effect of the use of isolators, in accordance with the present invention, depends on the distance between the parts or components isolated from each other. As the deflecting portion wall under load and collapses into or to partially ‘close’ the hollow, the distance between the two parts decreases, and the decreasing isolator cross section collapse the hollow so that the isolator leaves the range of noise and vibration and goes into the high energy impact and low compression movement condition.
In various aspects of the present invention, the isolator is made of a single material of a single (durometer) stiffness, and formed in a geometric shape that allows for deflection of a constant wall thickness at a first rate (first or deflection stage) (first load deflection rate) and compression of the final wall thickness at a second load/deflection rate or compression stage. The isolator or specifically the hollow portion of the isolator in the first stage, is flexed or deflected into an approximately flat configuration, and the overall wall thicknesses of hollow area, under increased load, to form the approximate thickness of the normal wall thickness for the compression stage. As load continues to increase, a second rate of higher load versus deflection occurs in the second or compression stage, with a uniform compression of the elastic material of the second isolator flattened hollow portion. The geometric shape change of the portions of the isolator provide for two separate load stages to meet the different misalignment, noise, and vibration and harshness conditions the components or parts are subject to. In various embodiments, the wall configurations distribute the load to an increased contact area at high inertia harshness conditions. In various embodiments, the geometric shapes are such that upon collapse, the walls ‘nest’ to form a uniform wall that minimizes the local stress on the thin wall areas to increase durability.
In various embodiments, the wall or walls of around at least one of hollow portions of the isolator have a slit or slits to separate sections of the walls to reduce overall tension in the isolator wall.
In a further embodiment of the present invention, the isolator, in addition to being tubular, can have a rib, or wiper rib or ribs, to allow for deflection characteristics related to lighter loads. For example, external wiper ribs may be used for soft positioning and noise absorption. In certain embodiments, the ribs are, in various embodiments, a positioned at angles of less than 90°to the contact surface tangencies so that they tend to deflect rather than compress. Also various embodiments are isolators with nesting pockets to receive the deflecting ribs to allow them to deflect flat with the normal contact surfaces to provide a uniform thickness at the surface of the isolator and the ribs fill the collapsing pocket for better distribution of heavier inertia loads.
In embodiments of the present invention, an isolator is made of an elastic or elastomeric material, or rubber or rubber like material. In various aspects, the isolator is formed or molded, as a single durometer stiffness material.
The isolator is formed in such a shape that allows a hollow portion between the contact surfaces of the isolator and between the contact surfaces of the heat exchanger and the opposing mounting frame such as shown in Figures. The hollow portion adjacent walls are of a thickness such that when they are deflected to a flat position approximately parallel to the contact surfaces of the heat exchanger and mounting frame walls, they form an approximately uniform thickness with the remainder of the isolator wall portions so that the entire flattened isolator can demonstrate an approximate uniform load. The isolator walls, in various embodiments, accept, at the area of the hollow portions, an initial inertia loading during higher frequency lighter load inertias. Fully deflected hollow area walls, along with the remainder of the isolator wall portions, have an approximate uniform thickness wall which accepts lower frequency higher inertia loads, for example, and distributes them with approximate uniformity through the isolator between an opposing heat exchanger assembly and mounting frame at their contact areas. A mounting frame can be described as a vehicle frame component, and engine drive train component, or another heat exchanger assembly component.
An isolator, in various aspects of the present invention, has a tubular shaped hollow wall portion that has a wall surrounding the hollow portion having a wall thickness of approximately 0.5 times (½) the normal flat wall thickness such that when the isolator tubular wall section is deflected to the flat position, the double wall forms with the normal wall thickness to be of an approximate uniform thickness.
In aspects of the present invention, an isolator is provided to maintain position space between a component heat exchanger and the adjacent mounting frame. The isolator is formed in such a shape that allows a hollow portion between the contact surfaces of the isolator and/or between the contact surfaces of the heat exchanger and the opposing mounting frame such as shown in
A rib, and, in particular, a wiper rib, of the approximate same durometer may be present.
Various embodiments with a rib or ribs utilize a non perpendicular rib or ribs that deflect and nest into a hollow cavity in the isolator. The size of such ribs can vary, as they should be able to be received in the volume of hollow when deflecting as shown in
In aspects of the present invention, having isolators, the ribs are spaced around the perimeter of the contact area to softly position one component or part (such as the heat exchanger) relative to a second component or part (such as a mounting frame of a vehicle) with contacting surfaces. Ribs, and, in various embodiments, so called wiper ribs, absorb noise vibration by maintaining separation of the heat exchanger isolator contact surface or opposing mounting frame contact surface off of the normal wall thickness of the isolator. By adding nesting ribs along the length of the tubular section outer wall of the isolator, in accordance with an aspect of the present invention, a 3rd stage so called “light” load resistance occurs that precede deflection of the tubular wall.
In
Housing mounting for a heat exchanger or fan shroud (15), in form of an housing slot and lower housing pin mountings, is shown. Vehicle lower mounting member (16), shows restricted vehicle lateral mount along pin, for example, during sharp right turn of the vehicle. Round pin tubular isolator (17) is illustrated between pin portion of housing (18) and hole in vehicle frame (19), with housing forward stopping movement G restricted also isolator pin, vehicle lateral L movement restricted along pin during sharp left turns, for example, upward rebound movement Y not restricted along lower isolator pin and loads H and K (vehicle resisting load during stopping) illustrated). Arrow V represents the direction to front of the vehicle.
Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. Plural structural components can be provided by a single integrated structure. Alternatively, a single integrated structure might be divided into separate plural components. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention.
The various embodiments of the present invention has been disclosed. A person of ordinary skill in the art would realize however, that certain modifications would come within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention.
| Number | Date | Country | |
|---|---|---|---|
| 60740784 | Nov 2005 | US |
