CZ29562U1 - Hydraulic damper - Google Patents

Description

Technical field

The invention relates to a method for controlling the damping force of a hydraulic damper, within which a liquid-filled housing is slidably connected to a piston connected to the piston rod, the space above and below the piston being interconnected by interconnecting channels in which the fluid flow control members are arranged.

BACKGROUND OF THE INVENTION

The hydraulic shock absorber, hereinafter referred to as the shock absorber, is an important element of the car chassis for ensuring both the vibration comfort of the crew and the load and for ensuring the even contact of the wheel with the ground. However, it appears that when the vehicle is driven to great unevenness, the damping force increases to such an extent that it represents a considerable impact force for the occupants, the load and the vehicle structure. Therefore, protection is sought against such a large load in the form of a degressive damper characteristic, where the damping force decreases instead of increasing after a certain relative damper velocity, being a passive uncontrolled damper. For shock absorbers (eg DE102005055801B3), a compliantly actuated element is commonly used which causes a decrease in the damping force increase as the relative velocity of the damper increases. These characteristics are also referred to as degressive, but degressive are only in the directive, not in the absolute value of the damping force, and this is not enough for shock protection. Therefore, shock absorbers (eg DE10105098C1, US20050016805A1) have been designed to provide a degressive characteristic, but only by irreversibly changing the damper due to the tearing of its structural members. Another solution is designed using controlled shock absorbers (eg US20040200946A1, US5937975A), but this requires a more complex design, power supply and electronics, which may be unreliable. The solution of the absolute value of the damper in absolute value with a return behavior based on the passive (uncontrolled) damper is still an open problem.

The aim of this technical solution is to create a solution of a passive damper with a degressive characteristic in the absolute value of the damping force, when the damping force decreases from a certain magnitude of the relative speed of the damper.

The essence of the technical solution

The essence of the hydraulic damper according to the invention consists in that the piston rod of the damper is connected to the actuating member for opening the connection hole between the space above the piston and below the damper piston.

The actuating member is a slip ring slidably guided on the piston rod and provided with wings, wherein a compression spring is arranged between the slip ring and the damper piston and a connecting hole extends through the piston rod. The disguised ring is provided with a through hole, the wings preferably having a concave shape.

Alternatively, the actuating member is a slip ring slidably guided on the piston rod and provided with wings, wherein a compression spring is provided between the slip ring and the damper piston and a connecting hole is provided in the damper piston against which a rotatable sealing plate or sliding sealing plate or ball valve is supported.

In another alternative, the actuator is a Pitot tube fixedly connected to the piston rod, the piston arranged in a portion thereof parallel to the piston rod is connected to a compression spring, the other end of which is connected to the damper piston, and a connecting hole is provided in the damper piston. on which a rotatable sealing plate or a sliding sealing plate or a ball valve abuts.

In another alternative, the actuator is a parallel damper whose piston rod with the piston is rigidly connected to the damper piston rod and the space above the piston is connected to a channel in which the piston is arranged against the compression spring with a slide provided with a connecting hole.

In another alternative, the actuator is a parallel damper whose piston rod with the piston is rigidly connected to the damper piston rod, the sliding housing of the parallel damper biased on both sides by fastening springs is connected by means of a rod to a piston arranged against the compression spring,

Which is connected to a slide provided with a connection hole. The diameter of the parallel damper piston is smaller than the inner diameter of the parallel damper shell.

In another alternative, the actuator is a Watt centrifugal regulator whose motion bolt is part of or is rigidly connected to the piston rod, the motion nut being connected via a rod to a plunger arranged against the compression spring and connected to a slide provided with a connection hole. A spring is arranged between the movement nut and the sliding sleeve. The piston rod is possibly a movement screw.

Clarification of drawings

Fig. 1 shows schematically the required course of the damping force,

Fig. 2 schematically shows the basic concept of a passive damper with a degressive characteristic, Fig. 3 schematically shows a perspective view of the concept of a solution of a passive damper with a degressive characteristic according to Fig. 2, Figs. 2 and 3,

Figure 4 schematically shows a variant for the solution of Figure 3,

Figure 5 schematically illustrates another variant for the solution of Figure 3,

FIG. 6 schematically illustrates a possible embodiment of a controlled damper with a parallel damper. FIG. 7 schematically illustrates another possible embodiment of a controlled damper with accumulator. Examples of technical solutions

FIG. 1 shows the desired course of the damping force F, the damper depending on the relative speed v j _re absorber movement. For the relative velocity 0 <v _re i <v, it is a progressive characteristic where the damping force F increases with the relative velocity increase both in absolute value and in the slope so that the slope of dF / dv _ret > 0 is positive and secondly, the slope of the dependence increases d (dF / dv _re i) / dv _re j> 0. For relative velocity V] <v _re i <v ₂ it is a progressive characteristic in absolute value, when the damping force F increases with the increase of relative velocity in absolute value (the slope of dF / dv _re i> 0 is positive), and it is degressive characteristic in the directive, where the slope of the dependence decreases (increment of the slope d (dF / dv _re )) / dv _rel <0 is negative). For relative velocity v ₂ <v _re i it is a degressive characteristic in absolute value, when the damping force F decreases with the relative velocity increase in absolute value v ₃ > v ₂ and F ₃ <F ₂ (slope dependence dF / dv _re j <0 is negative). The shock absorber design described below ensures the damping force profile for v> v ₂ . Today's standard solutions are used to solve dependencies in the interval <0, v ₂ >.

Today's traditional shock absorbers open holes in the piston body to transfer hydraulic fluid between the space above and below the piston and to equalize pressures. The opening is derived from the total damper pressure, which also corresponds to the relative velocity of the damper when the hydraulic fluid passage openings are closed between the space above and below the piston, but which does not decrease with the opening of the hydraulic fluid passage openings without decreasing the relative speed of the damper.

Fig. 2 shows schematically in cross-section the basic concept of a solution of a degressive damper consisting of a damper housing 1 and a damper piston 2 of a moving piston rod 3. In the piston body there is a connection channel 70 for transfer of hydraulic fluid between the space above and below the piston; for equalizing the pressures, which is opened by the total pressure in the damper acting on the sliding sealing plate 10, which overcomes the forces of the compression springs 8. Such holes in the damper body tend to be more and are located to move the damper piston 2 up and down. This is a traditional shock absorber solution to achieve the desired characteristic of Figure 1 for a relative velocity of 0 <v _re i <v ₂ . These connecting ducts 70 and sliding sealing plates 10 in the further Figures 3-13 for clarity will no longer be shown and their presence will only be assumed. The piston rod is moved by ailerons 4 mounted on the collar ring 5, between which a compression spring 8 is arranged between the piston 2 and the damper piston 8. In the collar ring 5, a through hole 6 is formed and a connecting hole 7 is formed in the piston rod 3.

-2GB 29562 U1 connecting the spaces above and below the damper piston 2, whose opening serves to decrease the damping force above the damper piston 2.

The function of the degressive damper of FIG. 2 is as follows. If the relative speed increases and the _re damper piston relative to the housing 2 and shock absorber, the pressure increases above the piston 2 and the shock absorber damping force damper. The dynamic pressure acting on the wings 4 on the sleeve 5 also increases and overcomes the force of the compression spring 8 acting against it. The dynamic pressure of the hydraulic fluid is the pressure caused by its movement relative to the movement of relatively standing surfaces, in the present case the wings 4. The sum of the static and dynamic pressure acts above the wings 4, the static pressure only acts under the wings 4. By overcoming the force of the compression spring 8, the sleeve 5 is moved and the through hole 6 in the sleeve 5 and the additional connecting hole 7 are opened between the spaces above and below the damper piston 2. This will cause the hydraulic fluid to flow from the space above the piston 2 to the space below the damper piston 2 and the pressure over the damper piston 2 will drop, thus reducing the damping force F of the damper shown in Fig. 1. ailerons 4 and which opens in a changeable opening 6 ring 5 and then an additional connecting opening 7 in the piston rod 3. the return of the cap ring 5 by the action of the spring 8, thereby closing the opening 6 in the annulus and the flow opening 7 occurs after the decrease of the relative velocity in _re, as required in FIG. 1.

FIG. 3 is a schematic cross-sectional view of an alternative concept of the degressive damper solution to that of FIG. 2 without the through hole 6 in the collar 5. The function of the degressive damper of FIG. 3 is similar to the embodiment of FIG. interconnecting channels 70 and sliding sealing plates 10 to achieve the traditional damper characteristics.

Fig. 4 is a schematic cross-sectional view; and Fig. 5 is a schematic view of a basic concept of a further alternative embodiment of a degressive damper consisting of a damper housing 1, a piston 2 of a movable piston rod 3. A compression spring 8 is arranged between the damper piston 2 and the damper piston 2. operating a rotatable sealing plate 9 mounted on a pin 12 which opens or closes the connection hole 7 in the body of the damper piston 2 between the spaces above and below the piston, thereby causing a damping force to decrease when the flow bore 7 is opened. The size of the flow orifice 7 is such that when it is opened, at a relative velocity of movement of the damper piston 2 with the piston rod 3 relative to the damper housing 1, greater than the velocity v ₂ shown in FIG. forces below F ₂ . It can be seen in FIG. 5 that the wings 4 can be made up of a simple disc only, but they can also have a more complex shape and can be divided into several parts.

The function of the degressive damper is based on the function of the solution in FIGS. 2 and 3. Applying a dynamic pressure to the wings 4 moves the collar 5 and rotates the rotary sealing plate 9 over the rod 11 and opens the connecting hole 7 between the spaces above and below the piston 2. This will cause the hydraulic fluid to flow from the space above the damper piston 2 to the space below the piston, and the pressure on the damper piston 2 will decrease and thus the damping force F of the damper shown in Fig. 1 will decrease. the velocity of movement of the damper piston 2 relative to the damper housing 1 below v ₂ .

Fig. 6 shows schematically in perspective another alternative concept of a solution of a degressive damper similar to that of Figs. 4 and 5. In contrast to the solution of Figs. 4 and 5, the rod 11 acts on the sliding sealing plate 10 guided in the sliding guide 13. the sealing plate 10 opens or closes the connection opening 7 between the spaces above and below the damper piston 2, thus causing a decrease in the damping force. The function of the damper derived from the movement of the ailerons 4 is the same as in FIGS. 4 and 5.

FIG. 7 is a schematic cross-sectional view of another alternative concept of a degressive damper solution similar to that of FIGS. 4 and 5, using rotation of the rotatable sealing plate 9 to open and close the connecting hole 7. Here the movement of the collar 5 acts on the rod Π. and acts on the rotation of the rotatable sealing plate 9 mounted on the pivot pin 12. The rod 11 is fixed with rotatable joints to the collar 5 and the lever of the rotatable sealing plate 9. The damper function derived from the movement of the ailerons 4 is the same as in Figures 4 and 5. Efficiency of dynamic pressure on

Here, the aileron 4 is reinforced by its concave shape which increases the resistance of the ailerons 4 when moving in a liquid.

Fig. 8 shows schematically in cross-section an alternative concept of a degressive damper solution to the solution of Fig. 6 by sliding the sliding sealing plate 10 to open and close the connecting hole 7. Here the movement of the sleeve 5 acts on the rod 15 and sliding the sliding sealing plate. The tie rod 15 is fixed to the sleeve ring 5 and to the sliding seal plate 10. The function is the same as the embodiment shown in FIGS. 4 and 5.

Fig. 9 is a schematic cross-sectional view of another alternative concept of a degressive damper solution. Here, the dynamic pressure from the movement of the damper piston 2 with the piston rod 3 relative to the damper housing I is determined by the Pitot tube 24. At its upper end d, the sum of the static and dynamic pressure in the hydraulic fluid is reflected and at its lower lateral end only static pressure in hydraulic fluid. Their difference, formed by the dynamic pressure and the corresponding relative velocity in the _reI of FIG. 1, acts on the piston 25 in the Pitot tube 24 and causes it to move against the spring force.

8. The movement of the piston 25 is transmitted to the movement of the rod 11. Further, in this solution, the rotary sealing plate 9 of FIG. 7 is replaced by a ball valve 14, in which the actual functional connection opening 7 connecting the spaces above and below the damper piston 2 is located. The ball valve 14 is inserted into the body of the damper piston 2 in which it is rotatable. Here, the movement of the piston 25 acts on the rod 11 and acts on the rotation of the ball valve 14 fitted into the body of the damper piston 2.

The function of the degressive damper is based on the function of the solution in FIG. 7. The dynamic pressure in the Pitot tube 24 causes the piston 25 to move and rotates the ball valve 14 over the rod 11 and opens the connecting hole 7 between the spaces above and below the piston. This will cause the hydraulic fluid to flow from the space above the damper piston 2 into the space below the piston and the pressure on the damper piston 2 will drop, thus reducing the damper force F of the damper shown in Fig. 1. the movement of the damper piston 2 relative to the damper housing 1 and the dynamic pressure drop in the Pitot tube 24.

FIG. 10 is a schematic cross-sectional view of another alternative concept of a degressive damper with a parallel damper. There is shown a powerful damper consisting of a damper housing 1, a damper piston 2, a piston rod 3. Again, connection channels 70 and sliding sealing plates 10 for achieving the traditional damper characteristics are not shown. In order to control its damping properties, the damper is provided with a bypass 17 in which at least one slide 18 is provided with a further connection opening 7 connecting the spaces above and below the damper piston 2, actuated by a spring 8 on one side and a control piston 19. A parallel damper consisting of a parallel damper shell 16, a parallel damper piston 21, a parallel damper piston rod 22 and a parallel damper 16 are provided in parallel. The piston rod 22 of the parallel damper is actuated in parallel with the piston rod 3 of the powerful damper by a connecting rod 20.

The function of the degressive damper in Fig. 10 is as follows. The movement of the piston rod 2 of the powerful damper is transmitted by the connecting rod 20 to the parallel piston rod 22 of the parallel damper. Thus, a damping force F is generated above the parallel damper piston 21 as a function of the movement of the parallel piston rod 22 of the parallel damper, similarly as above the powerful damper piston 2. If this force exceeds the value corresponding to the relative velocity v ₂ shown in Fig. 1, then the fluid pressure in the parallel damper acting on the piston 19 will overcome the force of the spring 8 and the slider 18 in the bypass will be moved so that and under the powerful damper piston 2. This will cause the hydraulic fluid to flow from the space above the damper piston 2 into the space below the piston and the pressure on the damper piston 2 will drop, thus reducing the damper force F of the damper shown in Fig. 1. the movement of the piston 21 relative to the parallel damper housing 16, which coincides with the relative speed of movement of the piston 2 relative to the executive damper housing 1, and the pressure drop over the piston 21 in the parallel damper and thereby the pressure on the piston 19. relative to the relative velocity in rela- _{tive of} a powerful and parallel damper, and not from the ratio of the pressures above and below the piston 2 of the damper as with today's traditional dampers.

-4GB 29562 Ul

FIG. 11 is a schematic cross-sectional view of another alternative concept of a degressive damper with a parallel damper similar to that shown in FIG. 10. A powerful damper comprising a damper housing I, a damper piston 2, a piston rod 3 is shown. Its damping properties are provided with a bypass 17 in which at least one bypass slide 18 is provided, provided with an interconnecting opening 7 connecting the spaces above and below the damper piston 2, actuated by a spring 8 on one side and a control piston 19 on the other side. 1, a parallel damper comprising a housing 16, a parallel damper piston 21 and a parallel damper piston rod 22 is provided in parallel. The piston rod 22 of the parallel damper is actuated in parallel with the piston rod 2 of the executive damper by a connecting rod 20. However, the parallel damper is attached to the executive damper by fastening springs 23. The parallel damper is connected to the control piston 19 by a rod 11 which is 19 articulated.

The function of the degressive damper in Fig. 11 is as follows. The movement of the piston rod 2 of the powerful damper is transmitted by the connecting rod 20 to the parallel piston rod 22 of the parallel damper. Thus, a damping force F is generated above the parallel damper piston 21 as a function of the movement of the parallel piston rod 22 of the parallel damper, similarly as above the powerful damper piston 2. If this force exceeds the value corresponding to the relative velocity v ₂ shown in Fig. 1, then the damping force occurring in the parallel damper overcomes the force of the fastening spring 23 and moves the rod H controlling the movement of the piston 19 and thus the slide 18 in the bypass 17 the connection opening 7 in the bypass 17 connects the space above and below the piston 2 of the powerful damper. This will cause the hydraulic fluid to flow from the space above the damper piston 2 into the space below the piston and the pressure on the damper piston 2 will drop, thus reducing the damper force F of the damper shown in Fig. 1. the movement of the parallel damper piston 21 relative to the parallel damper shell 16, which coincides with the relative velocity of the piston 2 relative to the executive damper shell 1, and the pressure drop over the piston 21 in the parallel damper and thereby the damping forces in the parallel damper acting on the retaining springs. and closing the connecting opening 7 is thus derived only from the relative velocity and in the _{re-performance,} parallel and not from the damper pressure ratio above and below the piston 2 as a shock absorber in today's conventional shock absorbers.

Fig. 12 shows schematically in section another alternative concept of a degressive damper solution with a Watt centrifugal regulator 26. It shows a powerful damper consisting of a damper housing I, a damper piston 2, a piston rod 3. This damper is bypassed to control its damping properties. 17, in which at least one slide 18 is arranged in the bypass with a flow opening 7 connecting the spaces above and below the damper piston 2, actuated by a spring 8 on one side and by a rod 11 on the other side. the centrifugal regulator 26 formed by the weights on the shoulders, the motion screw 27, the motion nut 28, the sliding sleeve 29. The motion screw 27 of the Watt centrifugal regulator is operated in parallel with the piston rod 2 of the powerful damper by a connecting rod 20.

The function of the degressive damper in Fig. 12 is as follows. The movement of the piston rod 2 of the powerful damper is transmitted by the connecting rod 20 to the movement of the motion screw 27 of the Watt centrifugal regulator and therefrom via the motion nut 28 to rotate the arms and weights of the Watt centrifugal regulator 26. This is made possible by the sliding sleeve 29 on the motion screw 27. If the relative speed of movement of the damper piston 2 relative to the damper housing 1 reaches the relative speed v ₂ in Fig. 1, then the angular speed of the motion screw 27 and the centrifugal force acting on the Watt centrifugal regulator that the movement and force of the rod H overcome the force of the spring 8 and the slide 18 in the bypass is displaced so that the connection opening 7 in the bypass 17 connects the space above and below the piston 2 of the powerful damper. This will cause the hydraulic fluid to flow from the space above the damper piston 2 into the space below the piston and the pressure on the damper piston 2 will drop, thus reducing the damping force F of the damper shown in Fig. 1. a movement screw 27, which is derived from the relative speed of movement of the piston 2 relative to the housing 1 of the powerful damper. The weights of the Watt centrifugal regulator 26 return to their original position under their weight. The opening and closing of the flow opening 7 is thus derived only from the relative speed

-5CZ 29562 Ul and the _{re-performance,} parallel and not from the damper pressure ratio above and below the piston 2 as a shock absorber in today's conventional shock absorbers.

Figure 13 is a schematic cross-sectional view of another alternative concept of a degressive damper with a Watt centrifugal regulator similar to that shown in Figure 12. Here, the piston rod 3 is simultaneously formed by a motion screw 27. Further, between the motion nut 28 and the sliding sleeve 29 a spring 30 that replaces the force of gravity on the weight of the Watt centrifugal regulator 26 when the motion screw is not in the vertical position.

All these solutions relate to the characteristic according to FIG. 1, where the relative velocity at _re > 0 is positive, and thus the piston 2 is moved upwards relative to the damper housing. The solution of the characteristic according to FIG. 1 for a negative relative velocity at _re < 0 and thus for the downward movement of the piston 2 relative to the damper housing I requires the use of additional elements 5, 9, 10, 14, 18 for opening and closing similar interconnecting holes 7 s. but in the opposite arrangement.

All these solutions and their parts can be combined with each other. For example, all the mechanisms for opening the flow opening 7 actuated by the ailerons 4 can be used with the Pitot tube 24 and vice versa. Or, for example, the spring 30 in Fig. 13 can be used for the concept in Fig. 12.

PROTECTION REQUIREMENTS

Claims (12)

A hydraulic damper, in which a fluid-filled housing is slidably arranged with a piston connected to a piston rod, the space above and below the piston being interconnected by interconnecting channels in which the fluid flow control members are arranged, characterized in that the damper piston rod (3) is connected to an actuator for opening the connecting hole (7) between the space above and below the damper piston (2). Hydraulic damper according to claim 1, characterized in that the actuating member is a swivel ring (5) slidably guided on the piston rod (3) and provided with wings (4), wherein a swivel ring (5) and a damper piston (2) are arranged. the compression spring (8) and the piston rod (3) pass through the connection opening (7). Hydraulic damper according to claim 1, characterized in that the sleeve (5) is provided with a through hole (6). Hydraulic damper according to claim 2 or 3, characterized in that the wings (4) have a concave shape. Hydraulic damper according to claim 1, characterized in that the actuating member is a swivel ring (5) slidably guided on the piston rod (3) and provided with wings (4), wherein a swivel ring (5) and a damper piston (2) are arranged. a compression spring (8) and in the damper piston (2) there is an interconnecting bore (7) on which a rotatable sealing plate (9) or a sliding sealing plate (10) or a ball valve (14) abuts. Hydraulic damper according to claim 1, characterized in that the actuating member is a Pitot tube (24) connected rigidly to the piston rod (3), wherein the piston (25) arranged in its part parallel to the piston rod (3) is connected to a compression spring. (8), the other end of which is connected to the damper piston (2), and in the damper piston (2) there is an interconnecting bore (7) on which a rotatable sealing plate (9) or a sliding sealing plate (10) or a ball valve (14). Hydraulic damper according to claim 1, characterized in that the actuating member is a parallel damper whose piston rod (22) with the piston (21) is rigidly connected to the damper piston rod (3) and the space above the piston (21) is connected to the channel. in which a piston (19) is provided against the compression spring (8) with a slide (18) provided with an interconnecting bore (7). -6GB 29562 Ul Hydraulic damper according to claim 1, characterized in that the actuating member is a parallel damper whose piston rod (22) with the piston (21) is rigidly connected to the damper piston rod (3), wherein the parallel damper sliding sheath (16) is biased on both sides by means of springs (23), it is connected by means of a rod (11) to a piston (19) arranged against a compression spring (8) which is 5 is connected to a slide (18) provided with a connection hole (7). Hydraulic damper according to claim 7, characterized in that the diameter of the piston (21) is smaller than the inner diameter of the shell (16) of the parallel damper. Hydraulic damper according to claim 1, characterized in that the actuating member is a Watt centrifugal regulator (26), the motion screw (27) of which is a part of the piston rod (3) or is fixed to it, the motion nut (29) being is connected by means of a rod (11) to a piston (19) arranged against a compression spring (8), which is connected to a slide (18) provided with a connecting hole (7). Hydraulic damper according to claim 10, characterized in that a spring (30) is arranged between the movement nut (28) and the sliding sleeve (29). Hydraulic damper according to claim 10, characterized in that the piston rod (3) forms a movement screw (27).