US20100155186A1 - Regulated Dashpot With Shock-Absorption Force Controls - Google Patents

Abstract

A regulable dashpot with shock-absorption force controls, especially intended for motor vehicles, with at least one flow-regulating system including one or more shock-absorption components for the compression phase and/or for the decompression phase. The object is to allow the dashpot to shift continuously between the hard and soft phases, whereby the valve-adjustment intervals can be varied at intervals that are not unnecessarily short or even unattainable. At least one valve assembly is accordingly supplied with variable flow impedance by regulating valve.

Description

CROSS REFERENCE OF RELATED APPLICATIONS
• This application is a divisional of U.S. application Ser. No. 10/008,895, filed Dec. 7, 2001.
CLAIM OF PRIORITY
• The present application claims priority from German application serial No. 100 62 99.7, filed on Dec. 16, 2000, the content of which is hereby incorporated by reference into this application.
BACKGROUND AND SUMMARY OF THE INVENTION
• The present application concerns a regulated dashpot with shock-absorption force controls, especially intended for motor vehicles.
• Regulated hydraulic dashpots with a flow-regulating system that shifts back and forth between compression and decompression phases in operation are known. Dashpots of this genus are described inGerman patent document 3 803 838 C2 for instance.
• One drawback of such dashpots is that their design permits them to shift only suddenly between the hard and soft phases, limiting the range of control. The comfort of the ride can be increased only to a limited extent.
• One object of the present invention, therefore is to provide a dashpot of the aforesaid genus that can shift continuously between the hard and soft phases, whereby the valve-adjustment intervals can be varied at intervals that are not unnecessarily short or even attainable.
• This and other objects and advantages are achieved by the regulated dashpot according to the present invention, which achieves a continuous transition between hard and soft phases in a simple manner. Valve-adjustment intervals can be maintained long enough to allow the device to be manufactured at justifiable component costs and to be operated at low requisite adjustment powers.
• One particular advantage is that the flow-regulating system can be modular and employed in different vehicles with various shock-absorption performances. Since there will be no sudden jolts when shifting between the hard and soft phases and vice versa, riding comfort will be considerably improved.
• Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a schematic illustrating how a dashpot can be regulated in accordance with a single-chamber principle;
• FIGS. 2 through 11 are schematics illustrating various other approaches to regulation in accordance with the single-chamber principle;
• FIGS. 12 and 13 are schematics illustrating how a dashpot can be regulated in accordance with a resilient-chamber principle and with a two-chamber principle; and
• FIG. 14 is a schematic illustrating regulation inside a dashpot cylinder.
DETAILED DESCRIPTION OF THE DRAWINGS
• The figures illustrate hydraulic circuitry specific to various dashpots. Each dashpot includes apiston3 mounted on the end of apiston rod2 and traveling back and forth inside acylinder1. Areservoir4 contains a compressed gas that compensates for the volume of hydraulic fluid displaced bypiston3.Reservoir4 can be integrated into the dashpot.
• FIG. 1 illustrates the hydraulic circuitry for a dashpot in accordance with the present invention. The dashpot includes two hydraulically parallel regulatingvalves5 and6. Hydraulically paralleling both regulatingvalves5 and6 is a very narrowlyconstricted bypass valve7, which can alternatively be integrated into one or both regulating valves.Bypass valve7 provides a minimal passage for the hydraulic fluid and accordingly prevents the dashpot from being entirely blocked while regulatingvalves5 and6 are closed. When closed, regulatingvalves5 and6 provide continuous regulation of the two phases (compressions, decompression) and, when closed allow the fluid to flow. Regulatingvalve5 regulates the flow whilepiston3 is traveling in the compression direction (compression phase) and regulatingvalve6 regulates it while the piston is traveling in the decompression direction (decompression phase). The rate of flow depends on the one hand on the difference between the pressure in anupper chamber8 and that in alower chamber9, the two chambers being separated bypiston3, and on the other hand on the cross-section of the passage through regulatingvalves5 and6, as dictated by flow controls like those known fromGerman patent document 10 040 518.
• FIG. 2 illustrates another embodiment of the circuitry illustrated inFIG. 1. In this embodiment, fluid can flow through both regulatingvalves5 and6 from either end as long as they are open, and the operative direction is prescribed byexternal checkvalves10 and11.
• FIG. 3 illustrates an advanced version of the circuitry illustrated inFIG. 2. It employs spring-loadedcheckvalves12 and13 instead of theexternal checkvalves10 and11. Such checkvalves will open to an extent that depends on the difference in pressure betweenchambers8 and9. The type of springs employed determines the intended performance curve of the dashpot in both compression and the decompression phases.
• FIG. 4 illustrates an advanced version of the circuitry illustrated inFIG. 3. It includes avalve assembly18 comprising unregulated spring-loadedcheckvalves16 and17 that parallel regulated spring-loadedcheckvalves12 and13. Checkvalves16 and17 parallel each other hydraulically and operate independently in both the compression and the decompression phases.Valve assembly18 can be integrated intopiston3 and acts as a standard spring loaded piston. The performance curve forvalve assembly18 is set to “hard” and that of regulated spring-loadedcheckvalves12 and13 to “soft”. Regulatingvalves5 and6 can accordingly now switch independently of each other and continuously back and forth between hard and soft in both the compression and the decompression phases. In addition tobypass valve7,bypass valves19 and20 can be introduced paralleling spring-loadedcheckvalves12 and13.
• This embodiment ensures constantly reliable driving performance even when the electricity or electronics fail. In such an event, regulatingvalves5 and6 will substantially close, and continued operation of the dashpot will be ensured by the mechanical action of the spring-loadedcheckvalves16 and17 invalve assembly18 at a hard performance curve, preferably withinpiston3, that is.
• The embodiment illustrated inFIG. 5 lacks the regulated spring-loadedcheckvalves12 and13 employed in the embodiment illustrated inFIG. 4. This embodiment is an advanced version of the regulable dashpot illustrated inFIG. 1, employing aparallel valve assembly18 like that in the version illustrated inFIG. 4. The bypass valve can also be eliminated.
• FIG. 6 illustrates an alternative to the embodiment illustrated inFIG. 5. Paralleling avalve assembly18 that comprises unregulated spring-loadedcheckvalves16 and17 with their hard performance curve are two similar spring-loadedcheckvalves12 and13 with a soft performance curve.Checkvalves12 and13 can be brought into play by way of associatedhydraulic switches21 and22, allowing a soft performance curve to be introduced whilepiston3 is traveling in either the compression or the decompression direction. Paralleling these are two parallel one-way checkvalves23 and24 with a soft performance curve that can be actuated and regulated by a regulatingvalve25. This circuitry again allows the shock-absorption performance curves to be established anywhere between hard and soft independently of each other as desired with the piston traveling in either direction.
• Circuitry similar to that illustrated inFIG. 6 can be attained as illustrated inFIG. 7. thesoft checkvalves12 and13 in this embodiment are provided with a two-to-threeway valve26 instead of two individual switching valves.
• FIG. 8 illustrates another alternative embodiment. Avalve assembly27 comprises two spring-loadedcheckvalves28 and29, each permitting the flow in a direction opposite that of the other.Checkvalves28 and29 have a soft performance curve and are alternately controlled by a two-to-threeway valve30. A flow-regulatingvalve31 continuously opens or closes a parallelhydraulics line32. Aconstricted bypass valve33 ensures minimal unimpeded flow.
• FIG. 9 illustrates an advanced version of the embodiment illustrated inFIG. 8. Upstream of flow-regulatingvalve31 is avalve assembly34 comprising two spring-loaded opposed-flow checkvalves35 and36. Checkvalves35 and36 also have a soft performance curve, although this curve can be varied between hard and soft.Bypass valve33, which, like the one illustrated inFIG. 8, can parallel flow-regulatingvalve31, two-to-threeway valve30, and/or the two series comprising a regulation-and-switching valve and checkvalves35 and36 or checkvalves28 and29, again ensures minimal flow as long as two-to-threeway valve30 and flow-regulatingvalve31 are closed.
• FIG. 10 also illustrates an advanced version of the embodiment illustrated inFIG. 8. This version includes, paralleling the components illustrated inFIG. 8, another, unregulable,valve assembly37 comprising spring-loaded opposed-flow checkvalves38 and39. Checkvalves38 and39 have a hard performance curve and can preferably be integrated into the piston in the form of standard cupspring-loaded valves.
• FIG. 11 illustrates another advanced version of the embodiment illustrated inFIG. 8. It includes avalve assembly27 comprising spring-loaded opposed flow checkvalves28 and29 with a soft performance curve, their direction of flow being reversed by a two-to-threeway valve30. The flow-regulatingvalve31 in this embodiment, however, parallelsvalve30, constantly maintaining thevalve assembly27 comprisingcheckvalves28 and29 in series with the latter. This embodiment also includes aconstricted bypass valve33 that ensures minimal flow.
• The flow-regulatingassembly40 represented by the dot-and-dash lines inFIGS. 1 through 11 is depicted in the form of a preferably self-containedblock41 inFIGS. 12 and 13. Flow-regulatingblock41 can also communicate withvalve assembly18,27,34, or37.
• The flow-regulatingblock41 represented inFIG. 12 is hydraulically interposed betweenlower cylinder chamber9 and pressure-compensatinggas reservoir4.
• FIG. 3 illustrates a double-cylinder dashpot with avalve assembly42 comprising two spring-loadedcheck valves43 and44 integrated into itspiston3. Abottom valve46 in the form of a spring-loaded one-way valve is interposed betweenlower cylinder chamber9 and a pressure-compensating reservoir represented by thespace45 between the cylinder's walls. The flow regulating assembly is preferably again in the form of a self-containedblock41 located outside the dashpot and hydraulically interposed betweencylinder chambers8 and9.
• The hydraulic switching-and-regulating components in the embodiment illustrated inFIG. 14 are integrated, like the components illustrated inFIG. 11, into the dashpot'spiston3.
• The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

Claims (12)

1. A regulated dashpot with shock-absorption force controls, for motor vehicles, comprising:

at least one flow-regulating system including at least one shock-absorption component for a compression phase and for a decompression phase;

at least one valve assembly with variable flow resistance, regulated by a regulating valve;

at least one fixed bypass valve with a non-varying constricted flow cross-section, hydraulically and directly paralleling the flow-regulating system, said fixed bypass valve having a constant opened flow-through cross-section hydraulically in parallel with said regulating valve; wherein,

said at least one flow regulating system for the compression phase and said at least one flow regulating system for the decompression phase are in the form of said regulating valve with variable flow constriction, whereby said flow resistance is continuously variable, for providing continuous damping between soft and hard damping;

said fixed bypass valve is integratable into said flow-regulating system and has a minimal passage for hydraulic fluid;

said flow-regulating system for the compression and decompression phases forms main flow channels through said shock-absorption component;

said valve assembly with electrically variable flow resistance forms a main valve assembly for said shock-absorption component;

said fixed bypass valve has a constant non-adjustable flow cross section; and

said regulated dashpot further comprises previously adjusted pressure-dependent valve assemblies for said compression phase and said decompression phase and having a hard performance curve, said valve assemblies hydraulically paralleling said flow-regulating system and said shock absorption component.

2. The regulated dashpot as defined inclaim 1, including previously adjusted pressure-dependent valve assemblies for said compression phase and said decompression phase and having a soft performance curve, said valve assemblies being activatable and deactivatable individually or separately, and being hydraulically parallel to said flow-regulating system and said shock absorption component.

3. The dashpot as defined inclaim 1, wherein at least one of said flow-regulating system and said shock-absorption component is accommodated in a piston thereof.

4. The dashpot as defined inclaim 1, wherein said flow-regulating system and said shock-absorption component are accommodated in a bottom valve thereof.

5. The dashpot according toclaim 1, wherein said flow-regulating system and said shock-absorption component are accommodated in a separate unit in form of a flow regulating block outside the dashpot and communicating with said dashpot through hydraulic-fluid lines.

6. The dashpot according toclaim 1, wherein said flow regulating system comprises two hydraulically parallel regulating valves, said bypass valve being hydraulically in parallel with said two regulating valves and having minimal passage for hydraulic fluid for preventing the dashpot from being entirely blocked while said regulating valves are closed.

7. An adjustable dashpot assembly with shock absorption force controls, said dashpot assembly comprising:

a dashpot having a piston that is displaceable within a cylinder;

at least one flow regulating shock absorbing system that includes at least one variable valve assembly for shock absorption in a compression phase and in a decompression phase;

at least one fixed bypass valve with a nonvariable constricted flow cross section that is constantly opened and is hydraulically in parallel with said variable valve assembly; and

a preset pressure dependent valve assembly for at least one of compression and decompression phases and having a hard damping characteristic, said preset pressure dependent valve assembly hydraulically paralleling the flow regulating shock absorbing system; wherein,

said at least one variable valve assembly has a variable flow resistance that is regulated by a regulating valve with a continuously variable flow constriction;

said flow resistance of said variable valve assembly is continuously variable for providing continuous damping according to shock absorption performance curves that can be set anywhere between hard and soft.

8. The adjustable dashpot assembly according toclaim 7, wherein said at least one flow regulating shock absorbing system comprises first and second hydraulically parallel regulating valves which regulate hydraulic fluid flow in the compression phase and in the decompression phase, respectively.

9. The adjustable dashpot assembly according toclaim 8, wherein said at least one flow regulating shock absorbing system further comprises first and second checkvalves that are connected hydraulically in series with the first and second regulating valves which control a direction of fluid flow through said regulating valves.

10. The adjustable dashpot assembly according toclaim 9, wherein said first and second checkvalves are spring-loaded checkvalves.

11. The adjustable dashpot assembly according toclaim 1, wherein said preset pressure dependent valve assembly comprises first and second unregulated spring-loaded checkvalves, which parallel the spring-loaded checkvalves in the at least one flow regulating shock absorbing system.

12. The adjustable dashpot assembly according toclaim 7, wherein said preset pressure dependent valve assembly comprises first and second unregulated spring-loaded checkvalves, which parallel the spring-loaded checkvalves in the at least one flow regulating shock absorbing system.

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