DE2122651C3 - Hydropneumatic suspension system with level control for vehicles, in particular motor vehicles - Google Patents

Description

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Radial bore 212) _{zvrnch ^ R}

SSslS? An2-BW.n.ng 131) connected
Axial stop (211) of the piston rod (.21)

^{This is the} atical suspension system

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'HVdrop pneumatic suspension system according to . nyuiup

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covers or

the hollow piston rod (21) is used

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(4145) 2-ur axial bore (4211) of the Κο '^ η rod ί (Ϊ) sealing like a slide valve

Suspension system according to

Sr piston rod (21) adjusts the up or down regulation

Suspension system according to

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the views 1 and 2 or 1 and 6, characterized in that a recess (101 1) at the liquid inlet, the helical spring (26) and the Fe ^{8 of} the (22 or 422) of the * ^ "^ 1 * ™ Oreans are so dimensioned, that the stop (25) firmly connected to the piston rod (21) only releases the fluid inlet when the pressure difference is greater than that required to respond to the pressure-sensitive organ.

The subject of the main patent 2 029 351 is a hydropneumatic suspension system with level control for vehicles, especially motor vehicles tools, consisting of struts with hydraulic level adjustment, inside or outside de Level regulators arranged on suspension struts, from a pressure flow arranged outside the suspension struts sigkeitsquelle with a high pressure accumulator, from egg

a liquid collecting tank, a high-pressure line connecting the spring struts or the level controller with the high-pressure storage tank, a return line connecting the spring struts or the level controller to the liquid collecting tank, and hydromechanical control retarders, one of which is built into the high-pressure line and one in the return line, which Respond to the pressure gradient in the high-pressure or return line that occurs when the respective level regulator is opened and release the passage with a delay, which, however, immediately return to its initial position blocking the passage whenever the relevant level regulator is closed, even if it is only briefly closed, with each control delay device having one in a cylinder against the force of a helical spring displaceable piston, which the cylinder in a provided with a fluid inlet piston end-side space and in a piston rod-side space which the screws takes up the spring and is connected to the piston-end space via a throttle bore u ^r d via further bores of larger cross-section controlled by a check valve opening in the direction of the piston-rod-side chamber, and which has a hollow piston rod which is sealed out of the cylinder and which is divided into a Subsequent to the cylinder, cylinder piece provided with a liquid outlet is immersed and has devices which open the passage from the liquid inlet to the liquid outlet with a predetermined displacement path of the piston.

In the case of the control retarder used in the suspension system according to the main application, the predetermined displacement of the piston a passage from the piston rod-side space to the inner Space of the hollow piston rod released. If one or more of them are only briefly immersed Fedeibeine in a control range and again entered the normal range comes to the Replacement of the volume of liquid that has already been displaced from the space on the piston rod side is required Amount of liquid by opening the non-return valve on the piston in the piston rod side Room of the control delay This check valve fulfills during the damped movement of the piston in the suspension system according to the main patent two functions that consist in the piston rod-roped space against the piston front side Space and seal against the inner space of the piston rod. As disadvantages are to be assessed: a possible sticking of the valve flap on the piston, causing its return to the starting position can be delayed and on the other hand the required high precision for the production of the Double valve seat.

The invention is therefore based on the object in the suspension system according to the main avoidance used to further develop the control delay so that it is possible in its entire structure is simple, requires little structural effort and that at the same time the required fast Return of the piston to the starting position is guaranteed and takes place more precisely than with the suspension system according to the main patent.

According to the invention, this object is achieved in that each control retarder is a pressure-sensitive one Has organ that is on the piston rod side when the piston is displaced Space-building damping pressure responds, shifted by this against the force of a spring and thus in the working position of the rule

hesitant blocks the passage from the liquid inlet to the liquid outlet until it is in the end position of the piston, the damping pressure in the space on the piston rod side is reduced, selecting in the rest position of the control retarder of the liquid

keitseinlaß is closed by a stop firmly connected to the piston rod.

Appropriately, the piston itself is designed as a pressure-sensitive member and on the Piston rod mounted so that it can be displaced to a limited extent

»5 he by the damping pressure against the force of a moved it against a locking ring on the piston rod pressing spring opposite the piston rod is and thereby a connecting hole between the piston-face space and one with

ao the fluid outlet connected to the axial bore the piston rod provided it. The constructive execution can be so, dz3 the piston with a Valve seat an axially extending bore in a test connected to the piston rod

ȣ valve body closes or releases or that the Piston in the manner of a slide has a radial bore in the hollow piston rod with the wall of its Central bore sealingly covers or releases. In the first case, the game

between the central bore of the piston and the hollow piston rod are used.

Another embodiment is designed so that a control piston in a pressure-sensitive member Hole in which is firmly connected to the piston rod

bound piston is displaceable, which has a connecting bore to the axial bore of the piston rod sealingly covers or releases in the manner of a slide.

Both versions of the pressure-sensitive or-

goose has in common that the controlled by the pressure-sensitive organ connecting hole between the The piston-face space and the axial bore of the piston rod also perform the up or down regulation process throttles and that a recess in the liquid

Keitseinlaß, the coil spring and the spring of the pressure-sensitive member are dimensioned so that the with the stop firmly connected to the piston rod, the liquid inlet only when there is a greater pressure difference releases than is necessary to address the pressure-sensitive organ.

The advantages achieved with the invention consist in particular that by utilizing the Damping pressure in the piston rod-side space of the control delay device to close the passage

more precise functions in the working position or to open the passage in the normal or rest position Reduction of the structural effort can be achieved.

It is also advantageous that in one embodiment the constant passage for damping the Movement of the piston and piston rod is formed by the clearance between the piston bore and piston rod can be, whereby the risk of clogging of this throttle cross-section due to contamination

6j tongue is reduced.

Embodiments of the used in the hydropneumatic suspension system according to the invention Control retarders are in the drawings

shown schematically in longitudinal section. It shows Fig. 1 a control delay in the rest position, FIG. 2 shows the control retarder according to FIG. 1 in the working position,

3 shows a modified control retarder with radial sealing of the passage and

F i g. 4 another modified control delay with separate piston lock.

A control delay in execution according to

piston-face space 23, whereby a damping pressure builds up in space 18 and a damped movement of the hollow piston rod 21 with the piston 14 takes place against the force of the helical spring 26 in the cylinder piece space 24. This process is ended by placing the spacer ring 28 on the cylinder cover 11.

When the hollow piston rod 21 is at a standstill, the damping pressure is applied via the throttle bore 142

Fig. 1 and 2 consists of an open on one side »o dismantled in space 18 and the spring 22 pushes the

Cylinder 10 with a cylinder bottom 101 and a piston 14 against the locking ring 19, whereby the

Connection piece 102. A cylinder cover 11 with a ~~ "~" Seal 12 closes off cylinder 10. Firmly connected

the one with the cylinder cover 11 is a cylinder piece

Passage for the liquid from the high-pressure accumulator via the space 23, the bores 201st the hollow piston rod 21 in the cylinder piece space 24 d d Fdb

13 with an Arischlußbohrung 131. In the cylinder 10> 5 and from there to the strut is opened. This ge

guided, a piston 14 is axially displaceable with a Piston seal 15 arranged. In addition, the piston 14 carries a valve seat 16, a check valve 17, which covers a bore 141 in the piston 14 in a space 18 on the piston rod side. Further the piston 14 has a throttle bore 142 with a constant passage. The piston 14 is axially displaceable between a locking ring 19 and a valve body 20 on a hollow piston

continues until the shock absorber has reached level again, its up-regulating valve closes and the Cylinder piece space 24 the pressure of the high pressure accumulator hcirscht. In this state, the Helical spring 26, a pressure drop from the piston-face space 23 to the piston rod-side space 18 reached, the check valve 17 opened and the hollow piston rod 21 with the piston 14 undamped very quickly back to their rest position.

rod 21 supported, which is firmly ^{guided with the valve body 20 3} S,
connected is. With this movement, the amount of liquid.

When the control retarder is in the rest position, the hollow piston extends through the volume Spring 22 of the piston 14 against the locking ring rod 21 corresponds to the bore 201 and the 19 and thus a connection from a hollow piston rod 21 into the cylinder piece space 24 benstirnseiten space 23 above the piston 14 promoted 3 °.

If one or more spring struts move only briefly into the upward regulation range, the damped movement of the hollow piston rod 21 begins into the cylinder piece space 24 and lasts for so long

by a helical spring 26, which is attached via a spring 35, like the regulating valve of the spring strut or struts dertellcr 27 is supported on the locking ring 19, is open. If all the regulating valves are closed again, so the hollow piston rod 21 moves with the piston 14 through the above-mentioned functions again undamped in their rest position.

Due to the spring 22, the control delay requires a certain minimum differential pressure between High pressure accumulator and shock absorber or between shock absorber and fluid reservoir. In order to avoid, that for example when cornering - where

spring struts, also not shown, are connected to the inside 45 in the full load condition of the vehicle, the pressure in the spring-mounted level regulators. leg equal to or greater than the pressure in the high-If the control retarder can be used as a shutdown retarder pressure accumulator - and used in a Ciffee, the connecting piece 102 is sealed with a pressure that is too low to the valve body 20 coming from the spring struts return line To press the valve seat 16, the through and the connection bore 131 remains open with a return bar 21 leading to a 5 ° passage via the bore 201 and the hollow piston-liquid collecting container, the spring 22 and the tubing are connected. Benfeder 26 and the cross-section of the recess If the regulating delay device 1011 is dimensioned in such a way that in this case it is used, then when the fitting 25 is immersed, the connecting piece 102 shuts off and the pressure in the cylinder 55 is roughly in the regulating range so the passage of liquid is prevented, the piece space 24 to the pressure of a gas spring in the case of the control retarder according to Fig. 3 is in place of the strut. Since the pressure in the high-pressure accumulator valve body 20 of the embodiment according to FIGS. 1 and 2 is always greater than the pressure of the gas spring in the level position of the spring strut limiting the movement of the piston 14 , there is a pressure gradient from the piston piece 29 fixed to the hollow piston rod 21 at the front end Space 23 connected to the cylinder piece space 24, 6o, which serves as a passage to the axial boring rune 211

Via a bore 201 in the valve body 20, the hollow piston rod 21, to a cylinder piece space 24 of the Cylinder piece 13 made.

A stop 25 on the valve body 20 is

tend to be pressed against a recess 1011 in the cylinder base 101. A spacer ring 28 limits movement the piston rod 21 into the cylinder piece space 24 by placing it on the cylinder cover 11.

When using the control delay as an up delay, the connector 102 is with a high-pressure accumulator, not shown, and the anchoring bore 131 with a high-pressure line

whereby the hollow piston rod 21 initially moves undamped into the cylinder piece space against the force of the spring 22 24 moves until the valve body 20 opens touches the valve seat 16 of the piston 14 (Fig. 2)

the piston rod has a radial bore 212. In the working position of the control retarder, a surface is set 291 of the spacer 29 on a piston surface 144 of the piston 14, and the radial bore 212

and the bore 201 closes off in a sealing manner. The river is sealed by the waodung of a central drilling

Fluid from the piston rod-side space 18 below the piston 14 now flows through the throttle bore 142 with constant passage rn den

tion 143 of the piston 14 closed.

The control delay device according to FIG. 4 has one Piston »414, which has a hollow piston rod 21

is firmly connected. A control piston 430 within the piston 414 S is controlled by eme

th diameter. Between a central bore 4143 of the piston 414 and a bore 4144 for the piston 430 there is a Vc-Jndunjbohrung 4145 for the passage of fluid, an axial bore 4211 of the piston rod 21

by building up the damping pressure

The space 18 on the piston side of the control piston 430 is displaced against the force of the spring 422 so far that its front edge 4302 touches a stop disk 432 , the connecting bore 4145 being closed by the wall of the control piston 430 and the passage of liquid from the space 23 on the piston face side to the axial bore 4211 the piston rod is prevented.

The other functions of the control delay devices according to FIGS. 3 and 4 correspond to the statements made with regard to FIGS. 1 and 2. In addition, apply mutatis mutandis. the functions described also for one as a control retarder in such a hydropneumatic! Suspension system built-in control delay.

1 sheet of drawings

Claims (2)

Patent claims: 1. Hydropneumatic suspension system with level control for vehicles, especially 5 motor vehicles, consisting of suspension struts with hydraulic level adjustment, level regulators arranged inside or outside the suspension struts, from a pressure fluid source with a high pressure reservoir arranged outside the suspension struts, from a liquid collecting tank, one of the suspension struts or the level regulator a high-pressure line connecting the high-pressure accumulator, a return line connecting the spring struts or the level controller with the liquid collecting container, and hydromechanical control retarders, of which a control retarder is installed in the high-pressure line and in the return line, each of which points to the opening of the respective ^ao level regulator in the high pressure or return line address the pressure gradient and release the passage with a delay, which, however, immediately when the level regulator in question closes, even if only briefly Gert return to their ^a 5 the passageway blocking initial position, each Regelverzögerer having a slidable in a cylinder against the force of a helical spring piston which divides the cylinder into a container provided with a liquid inlet piston end face Ra <in and into a piston rod side chamber, the 'ie The helical spring receives and is connected to the piston-face space via a throttle bore and via further bores of larger cross-section controlled by a non-return valve opening in the direction of the piston-rod-side chamber, and which has a hollow piston rod which is sealed out of the cylinder and which is connected to the cylinder , immersed with a liquid outlet provided cylinder piece and has devices ^{which open the passage from the liquid inlet 1} to the liquid outlet with a predetermined displacement of the piston, according to the main patent 2029351, characterized in that j Each control retarder has a pressure-sensitive element (piston 14 or control piston 430) , which responds to the damping pressure that builds up in the piston rod-side space (18) when the piston (14 or 414) is displaced, counteracting the force of a spring (22 or 422) ) is shifted and thereby blocks the passage from the liquid inlet to the liquid outlet in the working position of the control delay device until the damping pressure in the piston rod-side space (18) is reduced in the end position of the piston (14 or 414), while in the rest position of the control delay device the liquid inlet is closed by a stop (25) firmly connected to the piston rod (21). 2. Hydropneumatic suspension system according to claim 1, characterized in that the Piston (14) itself designed as a pressure-sensitive element and limited to piston rod (21) is slidably mounted so that he by the damping pressure against the force of a him 45