阅读说明：本技术 带有配备有浮动嵌套塞的自适应行程末尾止挡的减振器 (Shock absorber with adaptive end-of-travel stop equipped with floating nested plug ) 是由 F·邦特龙 C·蒙泰伊 J·M·阿莱格尔 A·卡瓦雷克 F·里盖勒 于 2020-02-10 设计创作，主要内容包括：本发明涉及一种液压减振器,所述液压减振器包括：减振器活塞(6),所述减振器活塞与主杆件(8)固定,并且在内部管件(4)中滑动；和补偿腔室(20),所述补偿腔室环绕所述内部管件(4),并且接收通过所述主杆件(8)进入所述减振器中而移动的流体,所述减振器活塞(6)于朝前处支撑着行程末尾止挡杆件(10),所述行程末尾止挡杆件包括处在自身的端部处的止挡活塞(12),所述止挡活塞进入止挡管件(14)中,所述止挡管件具有流体输出穿孔(18,34),所述补偿腔室(20)包括围绕着所述内部管件(4)轴向地滑动的且带有减速系统的嵌套塞(22),所述嵌套塞形成根据该补偿腔室(20)中的流体液位移动的浮子,所述浮子根据自身的移动作用在所述止挡管件(14)的可调节穿孔(34)上。(The invention relates to a hydraulic shock absorber, comprising: a damper piston (6) fixed with the main rod (8) and sliding in the inner tube (4); and a compensation chamber (20) surrounding the inner tube (4), and receives a fluid moving through the main rod (8) into the shock absorber, the shock absorber piston (6) supports an end-of-stroke stop rod (10) at a forward position, the end-of-stroke stop lever comprises a stop piston (12) at the end of itself, the stop piston enters a stop tube (14) having a fluid outlet bore (18, 34), the compensation chamber (20) comprising a nested plug (22) with a deceleration system axially sliding around the inner tube (4), said nested plug forming a float that moves according to the fluid level in the compensation chamber (20), the float acts on an adjustable perforation (34) of the stop tube (14) as a function of its own movement.)

1. A hydraulic shock absorber, said hydraulic shock absorber comprising: a damper piston (6) fixed with the main rod (8), sliding in the inner tube (4) and moving during compression towards an axial direction named front (AV); and a compensation chamber (20) surrounding the inner tube (4), and receives fluid displaced by the rod member (8) into the hydraulic damper, the shock absorber piston (6) supports an end-of-stroke stop rod (10) at a forward position, the end-of-stroke stop lever comprises a stop piston (12) at the end of itself, the stop piston enters a stop tube (14) having a fluid outlet bore (18, 34), characterized in that said compensation chamber (20) comprises a nested plug (22) with a deceleration system axially sliding around said inner tube (4), said nested plug forming a float that moves according to the fluid level in said compensation chamber (20), the float acts on an adjustable perforation (34) of the stop tube (14) as a function of its own movement.

2. Hydraulic shock absorber according to claim 1, wherein the nested plug (22) comprises a magnet (28) which acts on the adjustable perforation (34).

3. Hydraulic shock absorber according to claim 2, wherein the adjustable perforation (34) comprises valves (30) comprising magnets or magnetic material, the magnets (28) of the nested plug (22) acting on the valves (30) when the magnets of the nested plug face the valves.

4. Hydraulic shock absorber according to any one of the preceding claims, wherein each adjustable perforation (34) comprises a return spring (32) apt to close said adjustable perforation (34).

5. The hydraulic shock absorber according to claim 4, characterized in that the return spring (32) presses against the inner surface of the inner tube (4) to push the valve (30) onto the stop tube (14) so as to close the adjustable perforation (34).

6. Hydraulic shock absorber according to any of the preceding claims, wherein the nested plug (22) comprises a delay chamber (24) which is divided into two volumes by a fixed element (26) while allowing a leakage flow around the fixed element (26).

7. The hydraulic shock absorber according to claim 6, wherein the delay chamber (24) forms an annular volume which is in contact with the outer surface of the inner tube (4).

8. Hydraulic shock absorber according to claim 7, wherein the fixing element (26) forms an annular segment which engages in an outer groove of the inner tube (4).

9. A motor vehicle equipped with hydraulic suspension shock absorbers, characterized in that it comprises a hydraulic shock absorber according to any one of the preceding claims.

10. A motor vehicle according to claim 9, characterized in that, when the motor vehicle comprises a load exceeding a load threshold in a rest condition, the fluid level in the compensation chamber (20) causes the nested plug (22) to be arranged in its rear position.

Technical Field

The present invention relates to a hydraulic damper arranged with an end-of-stroke stop, and to a motor vehicle equipped with a damper of this type.

Background

Motor vehicles typically include a suspension for each wheel, the suspension including a suspension spring and a telescopic hydraulic shock absorber which decelerates the motion of the suspension. In particular, the shock absorber may include an end-of-stroke hydraulic stop that stops the end-of-stroke movement to avoid impact on the rigid stop.

One known type of adjustable end-of-stroke hydraulic stop is shown in particular by document US-A-3207270, which comprises A rod which receives the axial thrust of the movement to be decelerated and causes the piston to slide in A cylinder having A series of perforations distributed over its length. A manual control system arranged outside the cylinder is able to adjust the closure of these perforations in order to adapt the deceleration level of the stop.

However, the adjustment of this type of stop does not include any automatic action capable of adapting to different loads.

Another known type of stop for a vehicle suspension damper is shown in particular by the document FR-a1-3050000, which comprises a jack-rod member comprising a damper piston at its lower end to implement the main damping, said damper piston extending downwards out of a bushing which at the end of the compression stroke fits around the inner tube of the stop.

The bushing comprises a series of perforations distributed axially and closed in succession during the introduction of the tube into the bushing in order to decelerate more and more the transfer of the fluid (coming from the outer chamber formed around the bushing) towards the chamber (inside the tube and in front of the piston). An increasingly higher deceleration of the shock absorber at the end of the compression stroke is obtained.

The thrust spring is arranged below the main piston, pressing slightly before the end of the stroke of said shock absorber on a nested plug (boisseau) axially sliding in a stop tube comprising additional perforations at different heights.

A control chamber arranged in the stop tube and below the nested plug comprises a restricted passage for the outward communication of fluid, so as to slow down the descending movement of the nested plug under the action of the thrust spring and the re-ascending movement of the nested plug under the action of the return spring.

In this way, when a large jump of the suspension is accidentally carried out for a lightly loaded vehicle, the rapid pressing of the thrust spring against the nested plug does not cause the nested plug (decelerated by the fluid of the regulating chamber) to descend in a slow dynamic. The perforations of the stop tube remain open to provide greater flexibility for the end-of-stroke stop, which results in greater comfort.

In the case of a loaded vehicle, the thrust spring frequently presses against the plug insert, which frequently causes the plug insert to drop, which closes the bore of the stop tube and at the same time hardens the end-of-stroke stop more strongly. Safety is obtained by avoiding the rear contact (piloting) of the suspension of the loaded vehicle. However, a stop of this type comprising an adjustable nested plug inside the stop tube, which has perforations distributed along its length, is not suitable for including an end-of-hydraulic-stroke stop of the piston implemented inside the stop tube.

Disclosure of Invention

The object of the invention is in particular to avoid these disadvantages of the prior art.

To this end, the invention provides a hydraulic shock absorber comprising: a damper piston sliding in the inner tube and moving during compression in an axial direction named front; -a compensation chamber surrounding the inner tube and receiving a fluid moving through the main rod into the shock absorber, the shock absorber piston supporting an end-of-stroke stop rod in a forward direction, the end-of-stroke stop rod comprising a stop piston at its end, the stop piston entering a stop tube, the stop tube having a fluid outlet aperture, the shock absorber being characterized in that the compensation chamber comprises a nested plug axially sliding around the inner tube and with a deceleration system, the nested plug forming a float moving according to the fluid level in the compensation chamber, the float acting on an adjustable aperture of the stop tube according to its movement.

The advantage of this shock absorber is that for a shock absorber in a near vertical position, the fluid level in the compensation chamber forms an indicator for indicating the average load of the vehicle. By means of the decelerated sliding of the nested plug (for obtaining an adaptation of the height of the nested plug to the fluid mean level (which is not affected by rapid variations of the movement of the shock absorber), said nested plug can be lowered to close said adjustable perforation in the case of a lightly loaded vehicle with a higher chassis and a lower fluid level.

In this case, a deceleration law over a large stop travel is obtained, which ensures the comfort of the lightly loaded vehicle. The rapid travel of the stop does not move the spigot because of the slow dynamics of the spigot. In the case of a heavily loaded vehicle, the fluid level is higher and the nested plug eventually rises to open the adjustable perforation.

By means of these open perforations, a slight deceleration of the stop at the beginning of the stop stroke is obtained (which ensures the comfort of a vehicle with a low chassis), and a greater deceleration is obtained when these adjustable perforations are exceeded (to avoid a sudden end of stroke).

The hydraulic shock absorber according to the invention may also comprise one or more of the following features which may be combined with each other.

Advantageously, the nesting plug comprises a magnet acting on the adjustable perforation.

In this case, the adjustable perforation may comprise valves comprising magnets or magnetic material, which act on the valves when the magnets of the nested plug face them.

Advantageously, each adjustable perforation comprises a return spring which tends to close the perforation.

In this case, advantageously, the return spring is pressed against the inner surface of the inner tube to push the valve onto the stop tube in order to close the adjustable perforation.

Advantageously, the nested plug comprises a time delay chamber which is divided into two volumes by a fixed element, while allowing a leakage flow around the fixed element.

In this case, advantageously, the delay chamber forms an annular volume in contact with the outer surface of the inner tube.

Furthermore, advantageously, the fixing element forms an annular segment which engages in an outer groove of the inner tube.

The invention also aims to provide a motor vehicle equipped with a hydraulic suspension shock absorber comprising any of the above-mentioned features.

Advantageously, when the vehicle comprises a load exceeding a load threshold in a rest state, the fluid level in the compensation chamber causes the nested plug to be arranged in its rear position.

Drawings

The invention will be better understood and other features and advantages thereof will be more apparent from a reading of the detailed description given hereinafter by way of example and the accompanying drawings in which:

figure 1 shows, in an axial section, the front part of a shock absorber according to the invention in a rest condition, when the vehicle is unloaded; and

fig. 2 shows the shock absorber in a state of rest, when the vehicle is loaded.

Detailed Description

Fig. 1 shows a telescopic shock absorber comprising a front side indicated by arrow AV, an inner tube 4 arranged in an outer body 36, which inner tube houses a shock absorber piston 6 fixed on an intake rod 8, which shock absorber piston separates two hydraulic chambers to perform the main damping of the suspension movements. The volume between the outer body 36 and the inner tube 4 forms a compensation chamber 20 containing a pressurized gas, which receives a fluid overflow (tip-lein) derived from the volume displaced by the entry rod 8 into the shock absorber during compression of the shock absorber.

The intake rod 8 comprises an extension rod 10 in front of the damper piston 6, which includes a stop piston 12 at its front end, which is equipped with a sealing ring on its profile, which provides a slight leakage flow, which enters a stop tube 14 in the direction towards the end of the stroke of the damper, which comprises a front end bottom 16, which is connected to the inner tube 4 and to the outer body 36.

The stop tube 14 may in particular comprise a longitudinal slot starting from its rear end, said slot covering approximately half of its length and having a greater width at the rear end, which width tapers forward. Stop tube 14 may also include a plurality of series of tube perforations 18, each of which is arranged along a transverse plane to implement a deceleration law that is adapted to the position of stop piston 12.

A nested plug 22 arranged in the compensation chamber 20 is fitted around the inner tube 4 to enable it to slide axially along the tube while allowing the passage of the surrounding fluid.

The nested plug 22 comprises an annular delay chamber 24 arranged facing the inner tube 4 and comprising a segment 26 engaged in an external female neck of the inner tube to be maintained, so as to axially divide the chamber into two volumes with a small flow leakage between them.

The axial sliding of the nested plug 22 is slowed down by the fluid transfer between the two volumes of the delay chamber 24, which gives it a slow movement dynamics.

The nested plug 22 forms a float having a density less than the density of the fluid so as to follow the fluid level movement in the compensation chamber 20 with a time delay.

For light load vehicles with a higher chassis, the majority of the inlet rod 8 is outside the shock absorber, which results in a lower fluid level in the compensation chamber 20. The nested plug 22 is in the forward position. When the vehicle exceeds the load threshold via a load, such as a person or luggage, the entry rod 8 diverts fluid into the compensation chamber 20 and the nested plug 22 rises to a higher position.

In particular, when the suspension oscillates during travel (the oscillation having a frequency of about one hertz), the nested plug 22 substantially maintains the nested plug position assumed by the vehicle in a stationary condition, the slow transfer dynamics of the fluid in the delay chamber 24 slowing it sufficiently. The nested plugs 22 eventually move when the load differential of the vehicle changes the chassis of the vehicle.

The stopper tube 14 has perforations 34, each of which comprises a valve 30 arranged with a spring 32 that presses against the inner tube 4 to press it radially towards the inside against the outer surface of the stopper tube to close the perforation. The valve 30 includes a magnetic material or magnet.

The base of the nested plug 22 includes magnets 28 distributed over the contour of the nested plug, each of which faces a valve 30 when the nested plug is in the rear position shown in fig. 2, so as to attract the valve to compress the return spring 32 of the valve to maintain the valve open.

Fig. 1 shows an empty vehicle with a higher chassis, the nested plug 30 in its forward position and the valve 30 closed. The shock absorber is at the beginning of the end of stroke shown in the figure, the stop piston 12 beginning to enter the stop tube 14. This results in a gradual deceleration of the damper over the entire stop travel of the damper, which is carried out by using perforations 18 distributed over the length of the damper.

By gradually decelerating over the complete stroke of the end-of-stroke stop, a limitation of the body movement is obtained, which provides a high level of comfort.

Figure 2 shows the load-carrying vehicle in a stationary state with the inlet rod 8 having forced fluid into the equalizing chamber 20. After the transfer of fluid between the volumes of the delay chamber 24 has occurred, the nested plug 22 comes to its rear position, the magnet 28 of which attracts the valve 30, which opens. During the travel of the vehicle with small oscillations of the suspension, the stop piston 12 enters the stop tube 14 while remaining above the open adjustable perforation 34, these oscillations not being decelerated, which ensures comfort.

For large oscillations of the suspension, in particular for shocks on the suspension, the stroke of the stop piston 12 is extended below the adjustable perforation 34. This results in a greater deceleration of the end-of-travel stop over the remaining travel.

Thereby, for vehicles in load with a low chassis, a normal damping for small oscillations and a large deceleration over the remaining stroke for large oscillations are simultaneously obtained, which ensures comfort and road performance.

After the unloading of the vehicle has re-raised the chassis of the vehicle, the nested plug 22 is lowered in a slow dynamic as the fluid in the compensation chamber 20 is lowered to resume the starting position shown in figure 1.

Passive adaptive adjustment of the end-of-travel stop is obtained in a simple and effective manner and without connection to both the outside and the electrical system. Note that the end-of-travel stop includes a reduced number of components, which makes the end-of-travel stop cost prohibitive.

In particular, in the case of a vehicle in a stationary state, for a person load or a luggage load exceeding a load threshold, the chassis of the vehicle is lowered and the nested plug 22 is placed in its rear position with a delay, which provides an adaptive adjustment of the end-of-travel stop.