WO2017121418A1 - Hydraulic damper - Google Patents

Hydraulic damper Download PDF

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Publication number
WO2017121418A1
WO2017121418A1 PCT/CZ2016/000134 CZ2016000134W WO2017121418A1 WO 2017121418 A1 WO2017121418 A1 WO 2017121418A1 CZ 2016000134 W CZ2016000134 W CZ 2016000134W WO 2017121418 A1 WO2017121418 A1 WO 2017121418A1
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WO
WIPO (PCT)
Prior art keywords
piston
damper
regulation member
hysteresis mechanism
valve
Prior art date
Application number
PCT/CZ2016/000134
Other languages
French (fr)
Inventor
Michael VALÁŠEK
Pavel STEIBAUER
Zbyněk ŠIKA
Original Assignee
Čvut V Praze, Fakulta Strojni
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Čvut V Praze, Fakulta Strojni filed Critical Čvut V Praze, Fakulta Strojni
Priority to EP16822883.1A priority Critical patent/EP3445994A1/en
Publication of WO2017121418A1 publication Critical patent/WO2017121418A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/34—Special valve constructions; Shape or construction of throttling passages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/50—Special means providing automatic damping adjustment, i.e. self-adjustment of damping by particular sliding movements of a valve element, other than flexions or displacement of valve discs; Special means providing self-adjustment of spring characteristics
    • F16F9/516—Special means providing automatic damping adjustment, i.e. self-adjustment of damping by particular sliding movements of a valve element, other than flexions or displacement of valve discs; Special means providing self-adjustment of spring characteristics resulting in the damping effects during contraction being different from the damping effects during extension, i.e. responsive to the direction of movement

Definitions

  • the invention concerns a hydraulic damper which comprises a housing filled with a fluid, inside which a piston connected to a piston rod is guided axially, whereas the spaces above and under the piston are connected through connecting channels in which fluid flow rate control members are arranged.
  • a hydraulic damper thereinafter a damper, is an important element in a vehicle chassis used both to provide a vibration comfort for passengers and cargo and to ensure a uniform contact of a wheel with a road.
  • the damping force increases too much, which represents large impact loading for passengers, cargo and the vehicle bearing structure. Therefore a protection against such a large loading is demanded through degressive damper characteristics, where after exceeding a specific relative velocity the damping force decreases instead of increasing, whereas this is a passive non-controlled damper.
  • flexibility controlled elements are used in dampers (e.g. DE102005055801B3), causing a drop in the damping force increase, while a relative velocity of a damper movement increases.
  • dampers have been designed (e.g. DE10105098C1, US20050016805A1), which ensure degressive characteristics, but only through an irreversible change of a damper given by tearing its structural elements apart.
  • Another solution is proposed using controlled dampers (e.g. US20040200946A1, US5937975A), however, this requires a more complicated design, a power source and electronics that may be unreliable.
  • a solution for a degressive characteristic of a damper in the absolute value with a reversible behavior based on a passive (non-controlled) damper is still an open problem.
  • the aim of this invention is to create a solution of a passive damper with a degressive characteristic in the damping force absolute value, where the damping force decreases from a specific value of a relative velocity.
  • a hydraulic damper which comprises a housing filled with a fluid, inside which a piston connected to a piston rod is guided axially, whereas the space above and under the piston are connected through connecting channels in which fluid flow rate control members are arranged, lies in a fact that there is a connecting hole arranged in the damper piston for controlled fluid flow between the space above and under the piston using a regulation member, which is connected to a hysteresis mechanism.
  • a regulation member for the fluid flow control inside the connecting hole is a rotating plate connected to a control piston guided slidingly in a damper piston and connected to a compression spring.
  • a regulation member for the fluid flow control inside the connecting hole can be a linearly moveable plate connected to a control piston guided slidingly in a damper piston and connected to a compression spring.
  • a regulation member for the fluid flow control inside the connecting hole is a ball valve connected to a control piston guided slidingly in a damper piston and connected to a compression spring.
  • a regulation member for the fluid flow control inside the connecting hole is a linearly moveable plate connected to a piston through a compression spring and a drawbar or another compression spring with a hysteresis mechanism.
  • the hysteresis mechanism consists of a slide-valve with an inner piston or a ball with a piston rod for connection to a regulation member. Between a hysteresis mechanism piston rod and a regulation member an outer spring is arranged and the hysteresis mechanism is possibly connected to the regulation member through a parallel spring.
  • the hysteresis mechanism consists of a slide-valve with a ball with a piston rod for connecting to the regulation member, whereas the slide-valve comprises a direct branch with an inlet flap and an oval branch with an outlet flap, whereas the inlet flap and the outlet flap are connected to an inner spring.
  • Another alternative embodiment of the hysteresis mechanism consists of the slide-valve with the inner piston or the ball with the piston rod for connection to the regulation member, whereas a four-joint mechanism with a drawbar is arranged between the slide-valve with the inner piston or the ball with the piston rod and the regulation member.
  • Fig. 1 A schematic depiction of the required course of the damping force
  • Fig. 2 A schematic depiction of a basic concept of a passive damper with a degressive characteristic
  • FIG. 3 A spatial view on the basic concept of a passive damper with a degressive characteristic as depicted in Fig. 2
  • Fig. 4 A schematic depiction of an alternative embodiment of the basic concept of a passive damper with a degressive characteristic
  • FIG. 5 A spatial view on the concept of a solution of a passive damper with a degressive characteristic as depicted in Fig. 4
  • FIG. 11 to 16 Schematic depictions of various arrangements of the hysteresis element Examples of the Embodiments of the Invention
  • Fig. 1 shows a schematic depiction of a required course of F damping force of a damper depending on v re i relative velocity of the damper motion.
  • the relative velocity 0 ⁇ v re i ⁇ vt this is a progressive characteristic, where F damping force increases along with an increase of the relative velocity both in the absolute value and in the slope, thus applies that both the slope of the dependence dF/dv re i > 0 is positive and the slope of the dependence increases d(dF/dv re i)/dvrei >0.
  • Fig. 2 shows a schematic section and Fig. 3 a schematic view of a basic concept of a solution of a degressive damper consisting of housing I of a damper, piston 2 of a damper guided by piston rod 3.
  • control piston 5 In piston 2 of the damper there is a connecting hole 7 between spaces above and under piston 2, opening of which serves for a decrease in the damping force of the damper.
  • control piston 5 In the damper piston 2 there is also control piston 5 arranged, onto which pressure of the hydraulic fluid above the piston against compression spring 8 acts, and a movement of control piston 5 is limited by stop 6.
  • the motion of control piston 5 indicates the motion of drawbar 11, which through hysteresis mechanism 4 controls rotating plate 9 that opens or closes connecting hole 7 between spaces above and under piston 2, thus causing a decrease in the damping force above piston 2.
  • Drawbar _ ⁇ is attached to control piston 5 and hysteresis mechanism 4 by rotational joints.
  • a size of connecting hole 7 is such that when opened, the damping force decreases as depicted in Fig.
  • Hysteresis mechanism 4 serves for a delay of beginning of re-closing of hole 7 between spaces above and under piston 2.
  • a function of the degressive damper is as follows: If the relative velocity v re i of the damper piston 2 towards the damper housing 1 increases when piston 2 moves upwards, then the pressure above piston 2 increases and also the force of this pressure acting on control piston 5 increases, exceeding the value of the force of compression spring 8 acting against it.
  • drawbar IT gets moving and through hysteresis mechanism 4 the rotating sealing plate 9 attached on swivel pin 12 turns, opening connecting hole 7 between spaces above and under piston 2.
  • the hydraulic fluid starts to flow from the space above piston 2 to the space under piston 2 and the pressure acting on piston 2 decreases, as well as F 2 damping force decreases, as depicted in Fig. 1.
  • Hysteresis mechanism 4 ensures that the time initiation of acting of drawbar 1_1 through hysteresis mechanism 4 on re-closing of connecting hole 7 is shifted (delayed) both when control piston 5 moves upwards by acting of compression spring 8 and when drawbar II moves.
  • Particular variants of solutions of hysteresis mechanisms are described in next Figures 11 to 16.
  • Today's conventional dampers have differently opened connecting holes 7 after overpowering forces of springs corresponding to pressure in a damper caused by a value of the damper's relative velocity.
  • Fig. 4 shows a schematic section and Fig. 5 a schematic view on another concept of a solution of a degressive damper consisting of housing1 of a damper, piston 2 of a damper guided by piston rod 3.
  • piston 2 of the damper there is connecting hole 7 between spaces above and under piston 2, opening of which serves for a decrease in the damping force above piston 2.
  • control piston 5 arranged, onto which pressure of the hydraulic fluid above the piston against compression spring 8 acts, and a movement of control piston 5 is limited by stop 6.
  • the motion of control piston 5 indicates the motion of drawbar ⁇ , which through hysteresis mechanism 4 controls rotating sealing plate 9 guided in linear guide 13 .
  • a size of connecting hole 7 is such that when opened, the damping force above piston 2 decreases as depicted in Fig. 1 at relative velocities of the damper motion, i.e. a motion of piston 2 with piston rod 3 towards damper housing I, higher than velocity v 2 in Fig. 1.
  • Hysteresis mechanism 4 serves for a delay of beginning of re-closing of hole 7 between spaces above and under the piston.
  • the degressive damper function is similar to the function in Figs. 2 and 3. If the relative velocity v re i of the damper piston 2 towards the damper housing i increases, then the pressure above piston 2 increases along with an increase in the force of this pressure acting on control piston 5, exceeding the value of the force of compression spring 8 acting against it. By overpowering the force of compression spring 8 a move of control piston 5 is initiated, initiating also a move of drawbar IT of hysteresis mechanism 4 with connected linearly moveable sealing plate 10 fitted in linear guide 1_3. By the move of sealing plate 10 connecting hole 7 between the spaces above and under piston 2 opens.
  • Hysteresis mechanism 4 ensures that the time initiation of acting of drawbar ⁇ . through hysteresis mechanism 4 on re- closing of hole 7 is shifted (delayed) both when control piston 5 moves upwards by acting of compression spring 8 and when drawbar H moves.
  • Particular variants of solutions of hysteresis mechanisms are described in next Figures 1 1 to 16.
  • Fig. 6 shows a schematic section of another alternative concept of the solution of the degressive damper from Figs. 2 and 3 using turning of rotating sealing plate 9 for opening and closing of connecting hole 7.
  • control piston 5 acts on drawbar JJ_ through hysteresis mechanism 4 and drawbar H acts directly to turn rotating sealing plate 9 attached to swivel pin 12.
  • Drawbar ⁇ . is attached by rotational joints to hysteresis mechanism 4 and to the arm of rotating sealing plate 9. The function is the same as in the embodiment in Figs. 2 and 3.
  • Fig. 7 shows a schematic section of another alternative concept of the solution of the degressive damper depicted in Figs. 2 and 3.
  • Rotating sealing plate 9 from Figs. 2, 3, 6 is replaced by ball valve 14, in which the very functional connecting hole 7 that connects spaces above and under piston 2 is situated.
  • Ball valve 14 is arranged rotationally in piston 2.
  • the motion of control piston 5 acts on drawbar ⁇ through hysteresis mechanism 4 and drawbar 11 acts directly through the arm to turn ball valve 14.
  • the function is the same as in the embodiment in Figs. 2 and 3.
  • Fig. 8 shows a schematic section of another alternative concept of the solution of the degressive damper from Figs. 4 and 5 using a linear move of linearly moveable plate 10 for opening and closing of connecting hole 7.
  • the motion of control piston 5 acts on drawbar 15 through hysteresis mechanism 4 and drawbar 15 . acts directly to move linearly moveable plate 10 fitted in linear guide 13.
  • Drawbar 15 is fixed to hysteresis mechanism 4 and to linearly moveable sealing plate 10. The function is the same as in the embodiment in Figs. 4 and 5.
  • Fig. 9 shows a schematic section of another alternative concept of the solution of the degressive damper from Figs. 4 and 5 using a linear move of linearly moveable plate 10 for opening and closing of connecting hole 7.
  • Linearly moveable plate 10 fulfills also a function of control piston 5 here.
  • Linearly moveable plate 10 is through drawbar 15 directly connected to hysteresis mechanism 4 attached to the damper piston 2.
  • Hysteresis mechanism L3 fulfills a function of linear guide 13 through drawbar 15.
  • Drawbar 15 is fixed to hysteresis mechanism 4 and to linearly moveable plate 10. The function is the same as in the embodiment in Figs. 4 and 5.
  • Fig. 10 shows a schematic section of another alternative concept of the solution of the degressive damper from Fig. 9 using a linear move of linearly moveable plate 10. for opening and closing of connecting hole 7.
  • Linearly moveable plate 10 fulfills again a function of control piston 5 at the same time.
  • Drawbar ⁇ 5_ is not used, but linearly moveable plate 10 is through another compression spring 8 directly connected to hysteresis mechanism 4 attached to the damper piston 2.
  • Hysteresis mechanism 4 fulfills a function of linear guide 13 through compression spring 8. The function is the same as in the embodiment in Figs. 4 and 5.
  • hysteresis mechanism 4 is designed as an inner piston or ball 20 in slide-valve 2L
  • inner piston 20 has to be relocated from the left wall of slide-valve 21 to the right wall of slide-valve 21 and vice versa from the right wall of slide-valve 21 to the left wall of slide-valve 21. This way a delay of the initiation of action of drawbars through hysteresis mechanism 4 is realized.
  • hysteresis mechanism 4 is realized in parallel by inner piston 20 in slide-valve 21 with outer spring 22 and parallel spring 23.
  • hysteresis mechanism 4 is realized as piston in slide-valve 21_, where the piston is replaced by ball 20 or a roller enabling to rotate ball 20 in slide-valve 2L
  • hysteresis mechanism 4 is realized as a branched guide of the piston in slide-valve 21 , where the piston is replaced by ball 20 or a roller enabling to rotate the piston.
  • the slide- valve includes inlet flap 24 and outlet flap 25, which are kept in the depicted position or relocated back after displacement by inner springs 26.
  • Ball 20 moving in the straight branch of slide-valve 21 from the left wall of slide-valve 2J_ around outlet flap 25 shuts inlet flap 24 and moves as far as the right wall of slide-valve 21, where it starts to transfer the force to slide-valve 21.
  • inlet flap 24 causes a move of ball 20 into the bottom oval branch of slide-valve 2J_, from which it returns into the straight branch of the slide-valve through outlet flap 25.
  • the bottom oval branch of slide-valve 2 ⁇ is longer than its straight branch, resulting in an increase in hysteresis when piston 20 shown in Fig. 15 moves from the right side to the left side.
  • hysteresis mechanism 4 is realized by four-joint mechanism 27, which guides piston 20 in slide-valve 21.
  • the four-joint mechanism 27 improves the force transfer through slide-valve 21.

Abstract

The invention concerns a hydraulic damper which comprises a housing filled with a fluid, inside which a piston connected to a piston rod is guided axially, whereas the spaces above and under the piston are connected through connecting channels in which fluid flow rate control members are arranged, the subject matter of which lies in that there is connecting hole (7) arranged in the damper piston (2) for the controlled fluid flow between the space above piston (2) and under piston (2) using a regulation member, which is connected to hysteresis mechanism (4).

Description

Hydraulic Damper
Technical Field of the Invention
The invention concerns a hydraulic damper which comprises a housing filled with a fluid, inside which a piston connected to a piston rod is guided axially, whereas the spaces above and under the piston are connected through connecting channels in which fluid flow rate control members are arranged.
State-of-the-art
A hydraulic damper, thereinafter a damper, is an important element in a vehicle chassis used both to provide a vibration comfort for passengers and cargo and to ensure a uniform contact of a wheel with a road. However, when a vehicle runs onto a large bump, the damping force increases too much, which represents large impact loading for passengers, cargo and the vehicle bearing structure. Therefore a protection against such a large loading is demanded through degressive damper characteristics, where after exceeding a specific relative velocity the damping force decreases instead of increasing, whereas this is a passive non-controlled damper. Typically, flexibility controlled elements are used in dampers (e.g. DE102005055801B3), causing a drop in the damping force increase, while a relative velocity of a damper movement increases. These characteristics are also called degressive, however, they are degressive only in a slope, not in an absolute value of the damping force, which is insufficient for a protection against shocks. Therefore dampers have been designed (e.g. DE10105098C1, US20050016805A1), which ensure degressive characteristics, but only through an irreversible change of a damper given by tearing its structural elements apart. Another solution is proposed using controlled dampers (e.g. US20040200946A1, US5937975A), however, this requires a more complicated design, a power source and electronics that may be unreliable. A solution for a degressive characteristic of a damper in the absolute value with a reversible behavior based on a passive (non-controlled) damper is still an open problem.
The aim of this invention is to create a solution of a passive damper with a degressive characteristic in the damping force absolute value, where the damping force decreases from a specific value of a relative velocity. Subject Matter of the Invention
The subject matter of a hydraulic damper which comprises a housing filled with a fluid, inside which a piston connected to a piston rod is guided axially, whereas the space above and under the piston are connected through connecting channels in which fluid flow rate control members are arranged, lies in a fact that there is a connecting hole arranged in the damper piston for controlled fluid flow between the space above and under the piston using a regulation member, which is connected to a hysteresis mechanism.
A regulation member for the fluid flow control inside the connecting hole is a rotating plate connected to a control piston guided slidingly in a damper piston and connected to a compression spring.
Alternatively, a regulation member for the fluid flow control inside the connecting hole can be a linearly moveable plate connected to a control piston guided slidingly in a damper piston and connected to a compression spring.
Another alternative embodiment of a regulation member for the fluid flow control inside the connecting hole is a ball valve connected to a control piston guided slidingly in a damper piston and connected to a compression spring.
Another alternative embodiment of a regulation member for the fluid flow control inside the connecting hole is a linearly moveable plate connected to a piston through a compression spring and a drawbar or another compression spring with a hysteresis mechanism.
The hysteresis mechanism consists of a slide-valve with an inner piston or a ball with a piston rod for connection to a regulation member. Between a hysteresis mechanism piston rod and a regulation member an outer spring is arranged and the hysteresis mechanism is possibly connected to the regulation member through a parallel spring.
Alternatively, the hysteresis mechanism consists of a slide-valve with a ball with a piston rod for connecting to the regulation member, whereas the slide-valve comprises a direct branch with an inlet flap and an oval branch with an outlet flap, whereas the inlet flap and the outlet flap are connected to an inner spring.
Another alternative embodiment of the hysteresis mechanism consists of the slide-valve with the inner piston or the ball with the piston rod for connection to the regulation member, whereas a four-joint mechanism with a drawbar is arranged between the slide-valve with the inner piston or the ball with the piston rod and the regulation member. Overview of Figures in Drawings
The hydraulic damper as described in the invention is depicted in the attached Figures:
Fig. 1 A schematic depiction of the required course of the damping force
Fig. 2 A schematic depiction of a basic concept of a passive damper with a degressive characteristic
Fig. 3 A spatial view on the basic concept of a passive damper with a degressive characteristic as depicted in Fig. 2
Fig. 4 A schematic depiction of an alternative embodiment of the basic concept of a passive damper with a degressive characteristic
Fig. 5 A spatial view on the concept of a solution of a passive damper with a degressive characteristic as depicted in Fig. 4
Fig. 6 to 10 Schematic depictions of other embodiments
Fig. 11 to 16 Schematic depictions of various arrangements of the hysteresis element Examples of the Embodiments of the Invention
Fig. 1 shows a schematic depiction of a required course of F damping force of a damper depending on vrei relative velocity of the damper motion. For the relative velocity 0 < vrei < vt this is a progressive characteristic, where F damping force increases along with an increase of the relative velocity both in the absolute value and in the slope, thus applies that both the slope of the dependence dF/dvrei > 0 is positive and the slope of the dependence increases d(dF/dvrei)/dvrei >0. For the relative velocity vi < vrei < v2 this is a progressive characteristic in the absolute value, where F damping force increases along with an increase of the relative velocity in the absolute value (the slope of the dependence dF/dvrei > 0 is positive), and this is a degressive characteristic in the slope, where the slope of the dependence decreases (an increment of the slope d(dF/dvrei)/dvrei <0 is negative). For the relative velocity v2 < vrei this is a degressive characteristic in the absolute value, where F damping force decreases, while the relative velocity in the absolute value v3>v2 increases and F3<F2 (the slope of the dependence dF/dvrei < 0 is negative). The hereinafter described structural design of a damper ensures the damping force course for v>v2. Today's standard solutions are applicable for dependences within <0, v2> interval. Fig. 2 shows a schematic section and Fig. 3 a schematic view of a basic concept of a solution of a degressive damper consisting of housing I of a damper, piston 2 of a damper guided by piston rod 3. In piston 2 of the damper there is a connecting hole 7 between spaces above and under piston 2, opening of which serves for a decrease in the damping force of the damper. In the damper piston 2 there is also control piston 5 arranged, onto which pressure of the hydraulic fluid above the piston against compression spring 8 acts, and a movement of control piston 5 is limited by stop 6. The motion of control piston 5 indicates the motion of drawbar 11, which through hysteresis mechanism 4 controls rotating plate 9 that opens or closes connecting hole 7 between spaces above and under piston 2, thus causing a decrease in the damping force above piston 2. Drawbar _Π is attached to control piston 5 and hysteresis mechanism 4 by rotational joints. A size of connecting hole 7 is such that when opened, the damping force decreases as depicted in Fig. 1 at relative velocities of the damper motion, i.e. a motion of piston 2 with piston rod 3 towards damper housing \, higher than velocity v2 in Fig. 1. Hysteresis mechanism 4 serves for a delay of beginning of re-closing of hole 7 between spaces above and under piston 2.
A function of the degressive damper is as follows: If the relative velocity vrei of the damper piston 2 towards the damper housing 1 increases when piston 2 moves upwards, then the pressure above piston 2 increases and also the force of this pressure acting on control piston 5 increases, exceeding the value of the force of compression spring 8 acting against it. By overpowering the force of compression spring 8 drawbar IT gets moving and through hysteresis mechanism 4 the rotating sealing plate 9 attached on swivel pin 12 turns, opening connecting hole 7 between spaces above and under piston 2. Thus the hydraulic fluid starts to flow from the space above piston 2 to the space under piston 2 and the pressure acting on piston 2 decreases, as well as F2 damping force decreases, as depicted in Fig. 1. However, for the damping force to decrease below F2 value in Fig. 1, hole 7 has to remain open for a certain time. For this hysteresis mechanism 4 is used. After a decrease in the pressure and damping force above piston 2, control piston 5 returns to its position, but hysteresis mechanism 4 ensures that connecting hole 7 remains open for some longer time and the pressure and damping force above piston 2 are decreasing. Otherwise the degressive characteristic in the absolute value could not occur, but only the degressive characteristic in the slope, as typical in nowadays conventional damper designs. The application of the hysteresis mechanism is the subject matter of the described invention. Hysteresis mechanism 4 ensures that the time initiation of acting of drawbar 1_1 through hysteresis mechanism 4 on re-closing of connecting hole 7 is shifted (delayed) both when control piston 5 moves upwards by acting of compression spring 8 and when drawbar II moves. Particular variants of solutions of hysteresis mechanisms are described in next Figures 11 to 16. Today's conventional dampers have differently opened connecting holes 7 after overpowering forces of springs corresponding to pressure in a damper caused by a value of the damper's relative velocity.
Fig. 4 shows a schematic section and Fig. 5 a schematic view on another concept of a solution of a degressive damper consisting of housing1 of a damper, piston 2 of a damper guided by piston rod 3. In piston 2 of the damper there is connecting hole 7 between spaces above and under piston 2, opening of which serves for a decrease in the damping force above piston 2. In the damper piston 2 there is also control piston 5 arranged, onto which pressure of the hydraulic fluid above the piston against compression spring 8 acts, and a movement of control piston 5 is limited by stop 6. The motion of control piston 5 indicates the motion of drawbar ϋ, which through hysteresis mechanism 4 controls rotating sealing plate 9 guided in linear guide 13. of linearly moveable plate 10 that opens or closes connecting hole 7 between spaces above and under piston, thus causing a decrease in the damping force above piston 2. A size of connecting hole 7 is such that when opened, the damping force above piston 2 decreases as depicted in Fig. 1 at relative velocities of the damper motion, i.e. a motion of piston 2 with piston rod 3 towards damper housing I, higher than velocity v2 in Fig. 1. Hysteresis mechanism 4 serves for a delay of beginning of re-closing of hole 7 between spaces above and under the piston.
The degressive damper function is similar to the function in Figs. 2 and 3. If the relative velocity vrei of the damper piston 2 towards the damper housing i increases, then the pressure above piston 2 increases along with an increase in the force of this pressure acting on control piston 5, exceeding the value of the force of compression spring 8 acting against it. By overpowering the force of compression spring 8 a move of control piston 5 is initiated, initiating also a move of drawbar IT of hysteresis mechanism 4 with connected linearly moveable sealing plate 10 fitted in linear guide 1_3. By the move of sealing plate 10 connecting hole 7 between the spaces above and under piston 2 opens. Thus the hydraulic fluid starts to flow from the space above piston 2 to the space under the piston and the pressure acting on piston 2 decreases, as well as F damping force decreases. However, for the damping force to decrease below F2 value in Fig. 1 , hole 7 has to remain open for a certain time. For this hysteresis mechanism 4 is used. After a decrease in the pressure and damping force above piston 2, control piston 5 returns to its position to stop 6, but hysteresis mechanism 4 ensures that connecting hole 7 remains open for some longer time and the pressure and damping force are still decreasing. Without hysteresis mechanism 4 acting, the degressive characteristic in the absolute value of the damping force could not occur, but only the degressive characteristic in the slope of the dependence of the damping force and velocity, as occurs typically in nowadays conventional damper designs. Hysteresis mechanism 4 ensures that the time initiation of acting of drawbar Π. through hysteresis mechanism 4 on re- closing of hole 7 is shifted (delayed) both when control piston 5 moves upwards by acting of compression spring 8 and when drawbar H moves. Particular variants of solutions of hysteresis mechanisms are described in next Figures 1 1 to 16.
Fig. 6 shows a schematic section of another alternative concept of the solution of the degressive damper from Figs. 2 and 3 using turning of rotating sealing plate 9 for opening and closing of connecting hole 7. Here the motion of control piston 5 acts on drawbar JJ_ through hysteresis mechanism 4 and drawbar H acts directly to turn rotating sealing plate 9 attached to swivel pin 12. Drawbar Π. is attached by rotational joints to hysteresis mechanism 4 and to the arm of rotating sealing plate 9. The function is the same as in the embodiment in Figs. 2 and 3.
Fig. 7 shows a schematic section of another alternative concept of the solution of the degressive damper depicted in Figs. 2 and 3. Rotating sealing plate 9 from Figs. 2, 3, 6 is replaced by ball valve 14, in which the very functional connecting hole 7 that connects spaces above and under piston 2 is situated. Ball valve 14 is arranged rotationally in piston 2. The motion of control piston 5 acts on drawbar ϋ through hysteresis mechanism 4 and drawbar 11 acts directly through the arm to turn ball valve 14. The function is the same as in the embodiment in Figs. 2 and 3.
Fig. 8 shows a schematic section of another alternative concept of the solution of the degressive damper from Figs. 4 and 5 using a linear move of linearly moveable plate 10 for opening and closing of connecting hole 7. The motion of control piston 5 acts on drawbar 15 through hysteresis mechanism 4 and drawbar 15. acts directly to move linearly moveable plate 10 fitted in linear guide 13. Drawbar 15 is fixed to hysteresis mechanism 4 and to linearly moveable sealing plate 10. The function is the same as in the embodiment in Figs. 4 and 5.
Fig. 9 shows a schematic section of another alternative concept of the solution of the degressive damper from Figs. 4 and 5 using a linear move of linearly moveable plate 10 for opening and closing of connecting hole 7. Linearly moveable plate 10 fulfills also a function of control piston 5 here. Linearly moveable plate 10 is through drawbar 15 directly connected to hysteresis mechanism 4 attached to the damper piston 2. Hysteresis mechanism L3 fulfills a function of linear guide 13 through drawbar 15. Drawbar 15 is fixed to hysteresis mechanism 4 and to linearly moveable plate 10. The function is the same as in the embodiment in Figs. 4 and 5.
Fig. 10 shows a schematic section of another alternative concept of the solution of the degressive damper from Fig. 9 using a linear move of linearly moveable plate 10. for opening and closing of connecting hole 7. Linearly moveable plate 10 fulfills again a function of control piston 5 at the same time. Drawbar \ 5_ is not used, but linearly moveable plate 10 is through another compression spring 8 directly connected to hysteresis mechanism 4 attached to the damper piston 2. Hysteresis mechanism 4 fulfills a function of linear guide 13 through compression spring 8. The function is the same as in the embodiment in Figs. 4 and 5.
In Fig. 11 hysteresis mechanism 4 is designed as an inner piston or ball 20 in slide-valve 2L For transfer of the force, inner piston 20 has to be relocated from the left wall of slide-valve 21 to the right wall of slide-valve 21 and vice versa from the right wall of slide-valve 21 to the left wall of slide-valve 21. This way a delay of the initiation of action of drawbars through hysteresis mechanism 4 is realized.
In Fig. 12, the hysteresis of hysteresis mechanism 4 from Fig. Π. is enhanced by outer spring 22. The beginning of the force transfer is still delayed by the time needed for compression or extension of outer spring 22, which is also needed to overpower passive resistances.
In Fig. 13, hysteresis mechanism 4 is realized in parallel by inner piston 20 in slide-valve 21 with outer spring 22 and parallel spring 23. In Fig. 14, hysteresis mechanism 4 is realized as piston in slide-valve 21_, where the piston is replaced by ball 20 or a roller enabling to rotate ball 20 in slide-valve 2L
In Fig. 15, hysteresis mechanism 4 is realized as a branched guide of the piston in slide-valve 21 , where the piston is replaced by ball 20 or a roller enabling to rotate the piston. The slide- valve includes inlet flap 24 and outlet flap 25, which are kept in the depicted position or relocated back after displacement by inner springs 26. Ball 20 moving in the straight branch of slide-valve 21 from the left wall of slide-valve 2J_ around outlet flap 25 shuts inlet flap 24 and moves as far as the right wall of slide-valve 21, where it starts to transfer the force to slide-valve 21. However, in the opposite direction inlet flap 24 causes a move of ball 20 into the bottom oval branch of slide-valve 2J_, from which it returns into the straight branch of the slide-valve through outlet flap 25. The bottom oval branch of slide-valve 2\ is longer than its straight branch, resulting in an increase in hysteresis when piston 20 shown in Fig. 15 moves from the right side to the left side.
In Fig. 16, hysteresis mechanism 4 is realized by four-joint mechanism 27, which guides piston 20 in slide-valve 21. The four-joint mechanism 27 improves the force transfer through slide-valve 21.
All the mentioned solutions and their parts can be combined. For example, all mechanisms for opening of hole 7 can be arranged on the opposite side of piston 2, outer spring 22 can be also used for hysteresis mechanism in Figs. 14-16.

Claims

Patent Claims
1. A hydraulic damper which comprises a housing filled with a fluid, inside which a piston connected to a piston rod is guided axially, whereas the spaces above and under the piston are connected through connecting channels in which fluid flow rate control members are arranged, characterized in that there is connecting hole (7) arranged in the damper piston (2) for the controlled fluid flow between the space above piston (2) and under piston (2) using a regulation member, which is connected to hysteresis mechanism (4).
2. The hydraulic damper as described in Claim 1, characterized in that the regulation member for the fluid flow control inside connecting hole (7) is rotating plate (9) connected to control piston (5) guided slidingly in the damper piston (2) and connected to compression spring (8).
3. The hydraulic damper as described in Claim 1, characterized in that the regulation member for the fluid flow control inside connecting hole (7) is linearly moveable plate (10) connected to control piston (5) guided slidingly in the damper piston (2) and connected to compression spring (8).
4. The hydraulic damper as described in Claim 1, characterized in that the regulation member for the fluid flow control inside connecting hole (7) is ball valve (14) connected to control piston (5) guided slidingly in the damper piston (2) and connected to compression spring (8).
5. The hydraulic damper as described in Claim 1, characterized in that the regulation member for the fluid flow control inside connecting hole (7) is linearly moveable plate (10) connected to piston (2) through compression spring (8) and drawbar (15) or another compression spring (8) with hysteresis mechanism (4).
6. The hydraulic damper as described in Claims 1 to 5, characterized in that hysteresis mechanism (4) consists of slide-valve (21) with piston or ball (20) with a piston rod for a connection with the regulation member.
7. The hydraulic damper as described in Claim 6, characterized in that outer spring (22) is arranged between the piston rod of hysteresis mechanism (4) and the regulation member.
8. The hydraulic damper as described in Claim 7, characterized in that hysteresis mechanism (4) is connected to the regulation member by parallel spring (23).
9. The hydraulic damper as described in Claims 1 to 5, characterized in that hysteresis mechanism (4) consists of slide-valve (21) with ball (20) with a piston rod for connecting to the regulation member, whereas slide-valve (21) comprises a direct branch with inlet flap (24) and an oval branch with outlet flap (25), wherein inlet flap (24) and outlet flap (25) are connected to inner spring (26).
10. The hydraulic damper as described in Claims 1 to 5, characterized in that hysteresis mechanism (4) consists of slide-valve (21) with piston or ball (20) with a piston rod for a connection with the regulation member, whereas four-joint mechanism (27) with drawbar (1 1) is arranged between slide-valve (21) with piston or ball (20) with a piston rod and the regulation member.
PCT/CZ2016/000134 2016-01-11 2016-12-27 Hydraulic damper WO2017121418A1 (en)

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CZ20168000 2016-01-11
CZPV2016-8 2016-01-11

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115045944A (en) * 2022-07-19 2022-09-13 北京微动时空科技有限公司 Adjustable viscous damper for spacecraft

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5937975A (en) 1996-06-21 1999-08-17 Fichtel & Sachs Ag Vibration damper for a motor vehicle and a vibration damper having a damping valve with adjustable damping force for a motor vehicle
EP1110767A1 (en) * 1998-07-27 2001-06-27 Yevgeniy Yvanovich Ternovskiy Method for adjusting the resistance of a hydraulic damper, device for realising the same and variants
DE10105098C1 (en) 2001-02-05 2002-10-10 Zf Sachs Ag Vibration damper with overload protection
US20040200946A1 (en) 2003-04-12 2004-10-14 Zf Sachs Ag Vibration damper with amplitude-selective damping force
US20050016805A1 (en) 2003-06-06 2005-01-27 Zf Sachs Ag Vibration damper for vehicles
US20050056506A1 (en) * 2003-09-17 2005-03-17 Stefan Deferme Stroke dependent bypass
DE102005055801B3 (en) 2005-11-21 2007-02-15 Thyssenkrupp Bilstein Suspension Gmbh Vibration absorber for a motor vehicle's bodywork has an amplitude-selective absorbing device and pressure-limiting valves active in drawing and compression stages inside a bypass

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5937975A (en) 1996-06-21 1999-08-17 Fichtel & Sachs Ag Vibration damper for a motor vehicle and a vibration damper having a damping valve with adjustable damping force for a motor vehicle
EP1110767A1 (en) * 1998-07-27 2001-06-27 Yevgeniy Yvanovich Ternovskiy Method for adjusting the resistance of a hydraulic damper, device for realising the same and variants
DE10105098C1 (en) 2001-02-05 2002-10-10 Zf Sachs Ag Vibration damper with overload protection
US20040200946A1 (en) 2003-04-12 2004-10-14 Zf Sachs Ag Vibration damper with amplitude-selective damping force
US20050016805A1 (en) 2003-06-06 2005-01-27 Zf Sachs Ag Vibration damper for vehicles
US20050056506A1 (en) * 2003-09-17 2005-03-17 Stefan Deferme Stroke dependent bypass
DE102005055801B3 (en) 2005-11-21 2007-02-15 Thyssenkrupp Bilstein Suspension Gmbh Vibration absorber for a motor vehicle's bodywork has an amplitude-selective absorbing device and pressure-limiting valves active in drawing and compression stages inside a bypass

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115045944A (en) * 2022-07-19 2022-09-13 北京微动时空科技有限公司 Adjustable viscous damper for spacecraft
CN115045944B (en) * 2022-07-19 2024-01-16 北京微动时空科技有限公司 Adjustable viscous damper for spacecraft

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