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EP-4264082-B1 - SHOCK ABSORBER

EP4264082B1EP 4264082 B1EP4264082 B1EP 4264082B1EP-4264082-B1

Inventors

  • ANTONIONI, Angelo

Dates

Publication Date
20260506
Application Date
20201218

Claims (8)

  1. A shock absorber of the type comprising a cylinder (2) inside which a plunger (3) can slide which is provided with a sealing head (4) which abuts, instantaneously, on an annular portion of the inner surface (5) of said cylinder (2) in order to divide the inner cavity of said cylinder (2) into two separate chambers (6, 7) both containing a working fluid (L), said plunger (3) comprising an inner space inside which a cursor (8) can slide hermetically in abutment, instantaneously, on an annular portion of the inner surface of said space, thus delimiting two separate cells (9, 10), a first cell (9) containing said working fluid (L) and a second cell (10) containing a gas (G) at a predefined pressure, said sealing head (4) comprising at least one first one-way valve (11) and at least one respective transfer port (12) on said sealing head (4), said at least one first valve (11) being provided with at least one flow-limiting hole (13) for the damping of oscillations, upon an impulsive compression of said plunger (3), with consequent reduction of the overall length of said shock absorber (1), said at least one first valve (11) blocking said at least one transfer port (12), impeding the flow of working fluid (L) from said first chamber (6) to said first cell (9) through it and allowing said flow only through said at least one flow-limiting hole (13), with consequent rapid reduction of the pressure inside said second chamber (7) even to the point of cavitation of part of said working fluid (L) accommodated therein, until the impulsive compression ceases, characterized in that between said first cell (9) of said inner space and said second chamber (7) of said cylinder (2) there is at least one second one-way valve (16) which faces at least one respective second transfer port (17) defined on a side wall of said plunger (3), said valve (16) comprising at least one flow-limiting channel (18), and in that said at least one second valve (16) comprises a main element that translates along the sealing head (4) proximate to the outer side wall of said plunger (3), said main element being slideable between a first position of abutment against said side wall of said plunger (3), in which it blocks said second transfer ports (17) and the flow of working fluid (L) from said first cell (9) to said second chamber (7) is possible only through said limiting channel (18), and a second position at a predefined distance from said side wall of said plunger (3) in which said second transfer ports (17) are free and the flow of working fluid occurs through them from said first cell (9) to said second chamber (7) and vice versa.
  2. The shock absorber according to claim 1, characterized in that said at least one first valve (11) comprises a main body that translates along the inner surface of said space proximate to the sealing head (4), said main body being slideable between a first position of abutment against an end wall of said sealing head (4), in which it blocks said transfer ports (12) and the flow of working fluid (L) from said first cell (9) to said first chamber (6) is possible only through said limiting hole (13), and a second position at a predefined distance from said end wall of said head (4) in which the transfer ports (12) are free and the flow of working fluid (L) occurs through them from said first cell (9) to said first chamber (6) and vice versa.
  3. The shock absorber according to claim 1, characterized in that said at least one flow-limiting hole (13) is constituted by at least one through channel which is calibrated on the body of said at least one first valve (11) for the passage of a predefined maximum flow rate of said working fluid (L) from said first chamber (6) to said first cell (9).
  4. The shock absorber according to claim 1, characterized in that said cylinder (2) comprises, along its lateral surface, at least one first through opening (20) at said first chamber (6) and a second through opening (21) at said second chamber (7), said first opening (20) and said second opening (21) being coupled to components that are chosen from among stopper plugs (22, 23) and conduits of an external hydraulic circuit.
  5. The shock absorber according to claim 4, characterized in that said external hydraulic circuit comprises a reservoir of working fluid (L) and at least one pump for the conveyance of working fluid (L), through the respective conduits into said chambers (6, 7) of said cylinder (2), said pump being controlled by a respective control and management unit for the automatic control of said conveyance of working fluid (L), with consequent adjustment, discrete or continuous, of the excursion and position of equilibrium of said shock absorber (1).
  6. The shock absorber according to claim 1, characterized in that on the end wall of said second cell (10) of said inner space of said plunger (3) there is a passage duct (24) for said gas (G) for the adjustment of the pressure of said gas (G) in said second cell (10).
  7. The shock absorber according to claim 6, characterized in that said plunger (3) comprises an end plug (25) for hermetic closure which defines said end wall, said passage duct (24) being defined inside said end plug (25) and comprising at least one element (26) for the respective hermetic closure.
  8. The shock absorber according to one or more of the preceding claims, characterized in that it comprises a control and management unit which is connected to: - respective sensors for monitoring the road surface, - at least one compressor for the adjustment of the pressure of the gas (G) in said second cell (10), - at least one pump for the adjustment of the instantaneous quantity of working fluid (L) present in said first chamber (6) and in said second chamber (7), said control and management unit adjusting the pressure of said gas (G) in said second cell (10) and the quantity of working fluid (L) in said chambers (6, 7) as a function of signals detected by said sensors for monitoring the road surface, for the predictive adjustment of the stroke, of the elastic response and of the damping of said shock absorber (1).

Description

The present invention relates to a shock absorber of the universal type, suitable for numerous and separate applications and extremely versatile. Conventional shock absorbers, in particular those adapted for installation on vehicles of various nature and on industrial machinery, can be distinguished in terms of mechanical performance and behavior as a function of their response to external forces. Shock absorbers are widespread which are intended for applications in which the stresses are not impulsive and have an intensity comprised within predefined ranges: these devices allow a slow and uniform stroke of the stem (with a high linear excursion thereof) which ensures corresponding movements of the chassis with which they are associated. For example, vehicles for road use fitted with this type of shock absorbers are comfortable and make it possible to minimize perception of irregularities on the road surface. For applications where the stresses are impulsive and can have a very high level of intensity, "stiffer" shock absorbers are adopted, meaning that the damping of the stress is executed within a very short stroke and extremely rapidly. Again for the purposes of example, it should be noted that high-performance road vehicles adopt this type of shock absorbers. The use is known of adjustable shock absorbers, for example using a control computer that modifies the elastic response, the damping, and the extent of the stroke, with which it is possible to decide in advance between a behavior geared to comfort and a behavior more appropriate for motor sports (and optional intermediate settings). In any case, with reference to the example of the road vehicle, these adjustable devices require the user to select a specific mechanical behavior of the suspension in advance and therefore, while the vehicle is in operation, the suspension will behave exactly like a specific type of shock absorber (favoring comfort or rigidity of vehicle stability). The principal aim of the present invention is to solve the above-mentioned drawbacks by providing a shock absorber that is intrinsically versatile, i.e. that is adapted to provide the best response, both in terms of elasticity and in terms of damping, to external forces of widely varying intensity and duration. Within this aim, an object of the invention is to provide a shock absorber that is easily adjustable. Another object of the invention is to provide an active shock absorber. Another object of the invention is to provide a shock absorber whose operation is based on physical phenomena that are partially different and universally avoided by conventional devices. Another object of the invention is to provide a shock absorber with a structure that is relatively simple and extremely solid. Another object of the invention is to provide a shock absorber with a structure that is resistant to malfunctions. Another object of the present invention is to provide a shock absorber that is low-cost, easily and practically implemented and has competitive costs. This aim and these and other objects which will become more apparent hereinafter are achieved by a shock absorber according to claim 1. Further characteristics and advantages of the invention will become more apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the shock absorber, which is illustrated by way of non-limiting example in the accompanying drawings, wherein: Figure 1 is a schematic perspective view of a possible embodiment of a shock absorber according to the invention in an extended configuration;Figure 2 is a schematic perspective view of the shock absorber of Figure 1 in a compressed configuration;Figure 3 is an enlarged view of a detail of Figure 2;Figure 4 is a schematic perspective view of an additional embodiment of a shock absorber not according to the invention in a first extended configuration;Figure 5 is a schematic perspective view of the shock absorber of Figure 3 in a compressed configuration;Figure 6 is an enlarged view of a detail of Figure 5. With reference to figures 1-3, the reference numeral 1 generally designates a shock absorber according to the invention. The shock absorber 1 comprises a cylinder 2 inside which a plunger 3 can slide which is provided with a sealing head 4 which abuts, instantaneously, on an annular portion of the inner surface 5 of the cylinder 2 in order to divide the inner cavity of the cylinder 2 into two separate chambers 6, 7, both containing a working fluid L. It should be noted that the working fluid will preferably be an oil for shock absorbers and/or an oil for hydraulic circuits, although the possibility is not ruled out of using other working fluids. According to the invention, the plunger 3 comprises an inner space inside which a cursor 8 can slide hermetically in abutment, instantaneously, on an annular portion of the inner surface of the space, thus delimiting two separate cells 9, 10. A first cell 9 contains worki