EP3445994A1 - Hydraulic damper - Google Patents
Hydraulic damperInfo
- Publication number
- EP3445994A1 EP3445994A1 EP16822883.1A EP16822883A EP3445994A1 EP 3445994 A1 EP3445994 A1 EP 3445994A1 EP 16822883 A EP16822883 A EP 16822883A EP 3445994 A1 EP3445994 A1 EP 3445994A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- piston
- damper
- regulation member
- hysteresis mechanism
- valve
- Prior art date
- Legal status (The legal status 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 status listed.)
- Withdrawn
Links
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.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Fluid-Damping Devices (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CZ2016-8A CZ306614B6 (en) | 2016-01-11 | 2016-01-11 | A hydraulic shock absorber |
PCT/CZ2016/000134 WO2017121418A1 (en) | 2016-01-11 | 2016-12-27 | Hydraulic damper |
Publications (1)
Publication Number | Publication Date |
---|---|
EP3445994A1 true EP3445994A1 (en) | 2019-02-27 |
Family
ID=58452877
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP16822883.1A Withdrawn EP3445994A1 (en) | 2016-01-11 | 2016-12-27 | Hydraulic damper |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP3445994A1 (en) |
CZ (1) | CZ306614B6 (en) |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6918473B2 (en) * | 2003-09-17 | 2005-07-19 | Tenneco Automotive Operating Company Inc. | Stroke dependent bypass |
KR101375804B1 (en) * | 2011-09-02 | 2014-03-21 | 주식회사 만도 | Shock absorber with a frequency and pressure unit |
US9222539B1 (en) * | 2014-08-14 | 2015-12-29 | Tenneco Automotive Operating Company Inc. | Shock absorber with frequency dependent passive valve |
-
2016
- 2016-01-11 CZ CZ2016-8A patent/CZ306614B6/en not_active IP Right Cessation
- 2016-12-27 EP EP16822883.1A patent/EP3445994A1/en not_active Withdrawn
Also Published As
Publication number | Publication date |
---|---|
CZ20168A3 (en) | 2017-03-29 |
CZ306614B6 (en) | 2017-03-29 |
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