DE1265600B - Stabilization device on motor vehicles to prevent pitching movements when braking - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN MlMWt PATENTAMT Int. α .:

B 60g

EDITORIAL

German class: 63 c - 42

Number: 1265 600

File number: T1840011 / 63 c

Filing date: May 17, 1960

Open date: April 4, 1968

The invention relates to a stabilization device on motor vehicles for preventing pitching movements when braking, when between the vehicle frame and at least the rear wheel axle Hydraulic-pneumatic springs are arranged and one depending on the actuation of the hydraulic vehicle brake operating valve device for controlling the connecting line between the pressure medium springs and a pressure source is provided to with the help of the pressure medium springs to control the vertical distance between the vehicle frame and the vehicle axle.

Stabilization devices for motor vehicles are known. With such a hydraulically acting Device (German Auslegeschrift 1006 277) is controlled by a valve depending on the brake fluid pressure, the cross-sectional size of a changed the shock absorber chamber with a throttle opening connecting the storage chamber. Here is however, only the time constant determined by the throttle for the shock absorber pressure medium to flow away controlled under the action of the load acting on the shock absorber. At a Another known arrangement of a similar design (US Pat. No. 2184 202) is controlled the balancing oil flow between the shock absorber chambers of adjacent springs.

There is also a stabilization device known (German utility model 1 685 217), with which the centrifugal force when cornering can be counteracted with the help of the pressure medium springs. For this purpose, the valves for the four pressure medium springs are cross-shaped around one under the centrifugal force movable heavy body, e.g. a ball. The valves connect the individual pressure medium springs with a pressure medium tank. Instead of the control ball, another known one can also be used Device (German patent specification 930 067) a complicated balance beam system can be provided, which the elevation of two wheels of the same wheel axle in groups on the valve control brings to action. In these known arrangements, an increased pressure can be used to compensate. The equalization control can always only start when the movements to be compensated have already assumed a considerable extent.

A stabilization device for preventing nodding movements is also known (German patent specification 801423), in which a valve device which can be actuated by the braking device is provided, with the aid of which a stabilization device on motor vehicles is provided on the front
to prevent nodding movements when
Brakes

Applicant:

Thompson Ramo Wooldridge Inc.,

Cleveland, Ohio (V. St. A.)

Representative:

Dr.-Ing. F. Wuesthoff, Dipl.-Ing. G. Pulse
and Dr. E. v. Pechmann, patent attorneys,
8000 Munich 90, Schweigerstr. 2

Named as inventor:
Achilles Charles Sampietro,
Birmingham, Mich. (V. St. A.)

of the vehicle arranged adjusting cylinders pressure medium from a source depending on the Actuation of the brake can be supplied on one side. The other side of the cylinder stands with one Pressure equalization tank and with adjusting cylinders at the end of the vehicle in connection, so that this is a dependent or perform an indirect movement controlled by the front cylinders. This dependency However, it is not compulsory, but pressure-dependent, due to the activation of the expansion tank.

It is the object of the invention to provide a stabilization device of the type indicated at the outset create that directly and immediately counteracts the pitching movement when braking, namely regardless of the pressure or pressure prevailing in the pressure medium springs on the front of the vehicle. occurring pressure changes.

This object is achieved according to the invention in that the valve device is a per se In a known manner, one side can be acted upon by the brake fluid pressure, in the opposite direction has a prestressed valve element which, when displaced by the brake fluid pressure, the pressure medium springs the rear wheel axle connects to a low-pressure chamber.

When the vehicle brakes are actuated, the pressure in the rear wheel springs is therefore immediately relieved and inevitably. Since the discharge very quickly

809 537/359

3 4

and can be very effective, if the spring piston 28 is located, a hydraulic nodding movement is effectively countered. The control fluid which is located over the opening 29 of the rear axle therefore, 21b can move from the general between the chambers 21a and pressure in the suspension system, in particular so that the arrangement in the manner of a shock absorber the pressure prevailing in the springs of the front wheels 5 works, whereby the pneumatic spring is independent of a pressure. It can even be controlled with the braking in a manner to be explained. It should be noted at the same time, but independently of this, an increase in the fact that the opening 29 is caused by any pressure in the suspension system. biges, designed in a known manner flow-If the vehicle frame can replace the front and control valve for a shock absorber. Ia the rear axle is supported by pressure medium springs in the space 30 between the spring piston 28 and the, the arrangement can advantageously be reached in such a way that the upper end of the cylinder 21 is air or a non-explosive gas, depending on the braking. Liquid pressure operating valve device which is highly compressed and acts as a pnel-exceeding of a predetermined pressure value matic spring between the rear axle 17 and the frame 10 simultaneously with the relief of the pressure medium springs 15. The spring constant of the pressure of the rear wheel axle in a manner known per se, the central springs 21c, 21d can be varied with the pressure in the space 30 by changing the gas pressure medium springs of the front wheel axle.
Pressure source connects. According to FIG. 1 is each pressure medium spring 20 a, 20 h,

The invention is described below with reference to 20c and 20d to a pressure source 31 in the form of a schematic drawings of an embodiment ao accumulator for a under high pressure

example explained in more detail. Fluid can be closed, which can be

Fig. 1 is a schematic plan view of a known manner. The horizontal

the stabilization device according to the invention height position of the frame 10 controlling Ventileinrich-

equipped motor vehicle; lines 32 and 33 can do this under high pressure

F i g. FIG. 2 is a partial section along the line H-II in FIG. 25 standing fluids from the pressure lines 34

Fig. 1; or 35 to the front Druckmittelfedem20a and

Fig. 3 is a drawn on a larger scale 206 or to the rear Druckmittelfedem20c

Longitudinal section through a control of the horizontal elevation and 20 d . Furthermore, there are the valve devices

valve means controlling the vehicle frame; 32 and 33 through low pressure lines 38 and 39, respectively

F i g. 4 shows a longitudinal section of a valve device used in the system 30 with a low-pressure chamber 36 and via the control according to FIG. 1 for directing 40, 40a or 41 and 41a directly to prevent nodding movements. the relevant pressure medium springs 20 α, 20 b or

Fi g. 1 shows a generally known manner from 20 c, 20d connected.

formed motor vehicle with a frame 10 and the valve devices 32 and 33 regulate the four wheels 11, 12, 13 and 14, the front 35 amount of contained in the Druckmittelfedem

Wishbones 15 and 16 and a rear axle 17 with hydraulic pressure medium and are through

the frame 10 are connected. The wishbones 15 actuated valve levers 42 and 43, which are U-shaped

and 16 are against the frame 10 by a hydraulic anti-roll bars 44 and 45 of the usual construction

lisch-pneumatic suspension system supported, the middle of which are connected. According to Fig. 1 is the

whose front pressure medium springs 20 α, 20 & the point 40 cross stabilizer 44 on the frame 10 in yielding

the otherwise common mechanical springs a bushings 44 & mounted and over its ends 44 a with

to take. Also between the frame 10 and the outer ends of the wishbones 15 and 16

Rear axle 17 are pressure medium springs 20 c, 20 if connected in a pre-articulated manner, while in a corresponding manner

seen. The hydraulic-pneumatic systems for the anti-roll bar 45 by means of its ends 45 a with

the two axles are essentially the same as the rear axle 17 is connected. The valve levers 42

formed, which is why so far in the following are in agreement ■ or 43 are therefore proportional to the mean value

There is a mung that only at the rear end of the wheel lofts of the front wheels 11, 12 or the

Vehicle provided units with further rear wheels 13,14 moves. When considering the driving

Details are described. it moves stuff from its left side

According to FIG. 2, the pressure medium springs 50 include valve levers 42 when the load increases

each have an outer cylinder 21 with a lower frame 10 counterclockwise while

Chamber 21 b, which is moved downwards by a piston, in this case the valve lever 43 in a clockwise direction

'22 a is limited. The cylinder 21 is moved at 23 on the.

Articulated frame 10, and the piston 22 a. The valve devices 32 and 33 are similar The supporting piston rod 22 is formed with one on the 55, specifically in the form shown in FIG. 3 can be seen Rear axle 17 attached bearing block 25 at 24 ge way; F i g. 3 shows the rear valve pivot as an example tied together. The rear axle 17 is according to device 33. The valve lever 43 moves a Be-F i g. 1 and 2 with the engine of the vehicle by actuating rod 46, which is connected to a total of 47 a thrust tube 26 or an equivalent radius-designated piston slide is connected to the two Handlebars for determining the position of the rear wheels 60 separated from one another by an annular groove 50 tied together. The lateral stability can also have webs 48 and 49. The piston valve 47 be secured by any linkage means. is within the valve housing 51 by springs

The cylinder 21 further includes an upper chamber 52 and 53 centered; in its middle or neutral

21a, the position with a control line described later, the piston valve 47 locks both the

41 connected and from the lower chamber 21 & 65 high pressure line 35 as well as the low pressure line

is separated by a perforated partition 27. 39 opposite the control line 41a, which leads to the

In the space between the piston 22 a and a pressure medium spring 20 c and 20d leads. If

the upper chamber 21 α upwardly closing the valve lever 43 when a load is applied

5 6

the frame 10 according to FIG. 3 clockwise since the pressure medium moves the two rear pressure paths, the piston slide 47 moves to the left central springs 20 c and 2Od at the same time and connects the high pressure line 35 with the is, the transverse position of the vehicle frame 10 of the control line 41 a, whereby the under The pressure of the valve device 33 is not influenced, while hydraulic medium is introduced into the upper chamber 21a 5 together with the valve device 32 (Fig. 2) in order to press the piston rod 22 downwards in the horizontal position of the vehicle and thus the frame 10 to constantly lift upright over the rear axle 17 in the event of a static load change until the valve is maintained. Delays or accelerations of the lever 43 to its intended position according to FIG. The vehicle results in a dynamic axle load in which the piston valve 47 again assumes its position between the front wheels and the rear center position. wheels without changing the total static load.

To prevent small short-term spring-A rapid application of the vehicle brakes movements as a result of uneven road surfaces while driving with a relatively high level of riding a change in the altitude of the vehicle speed leads to a very high speed cause frame, according to FIG. 3 at 55 is a 15 dynamic load on the front end of the vehicle, so limited resilient connection between the frame 10 and the front wheels 11 the valve lever 43 and the actuating rod 46 and 12 is pressed down, resulting in actuation provided, which leads one of the resilient material of the valve device 32. Since their position existing socket between the end 43 a of the change according to the form described so far Valve lever 43 and the eye 46 a of the actuation 20 is delayed, the altitude would be when braking rod 46 includes. This socket can always be delayed and to avoid within her the frame 10 Short-term movements of the valve-a brake nod to work are regulated too late, so that hebeis 43 without a corresponding actuation of the undesired vertical movements of the vehicle piston valve 47 to, while they would, however, occur a frame 10 opposite the wheels. The piston slide 47 is displaced if 25 To quickly change the frame position when braking Valve lever 43 deflected through a longer period of time and a downward movement of the vehicle will be. It should be noted that you can also prevent any other frame 10 against the front wheels in the similar design of a flexible, with dead gear bringing braking forces is according to working connection could provide to one of the invention a further valve device 60 to effect such delay. 30 (Figs. 1 and 4) to prevent nodding

In addition to the one described, it is provided to a limited extent when braking. As from Fig. 1 generous connection 55, the webs 48 and 49 of the can be seen, the valve device 60 can be the pressure piston valve 47 designed in such a way that it channels the ring means from the high pressure source 31 35 a or 39 a at 48 a or 49 a in the included line 61 via a line 62 to the overlap a bit. Let this overlap 35 flow control line 40 and at the same time that prevents the pressure medium control by the pressure medium from the control line 41 via the Piston valve 47 matched up to the occurrence of a pre-lines 63 and 64 to the low-pressure chamber 36 Minimum change in vehicle load. let run.

F i g. 3 shows this overlap in exaggerated form. The valve device 60 is shown in FIG. 4 with their Scale. In the parxis, the overlap is shown in detail. It embraces one in one generally only a fraction of a millimeter. Housing 66 reciprocable valve element In addition to the provided at 43 a, limited 65 in the form of a piston valve with ring resilient connection 55 can in the system grooves 70 and 71 separate control also A delay device is also provided, webs 67, 68 and 69. The pressure medium line 61 to make it less sensitive to intermittent 45 feeds an annular channel 72 of the housing 66 while making short-term impacts; one such is attached to a further annular channel 73, the low-pressure delay device can line 64 connects in the form of a throttle. An annular high pressure in the valve devices 32 and 33 with the outlet channel 74 leads the line 62 the pressure medium Control lines 40 and 41 connecting lines when the piston valve 65 according to FIG. 4 after

40 a and 41 a. Such a throttle 50 is moved to the right, and this connects an effect can be caused by a smaller diameter of further annular channel 75 at the same time the low-pressure lines 40 α or 41a line 64 with the control line 41 of the rear, as shown in Fig. 4 by the corresponding pressure medium springs 20c and 20d.
Dimensions of these lines is indicated. It should be noted that the piston valve 65 under

When unloaded, the vehicle frame 10 55 moves through the usual circumstances in a chamber up. This causes a movement of the valve lever that is present, its one end face 43 counterclockwise protruding hydraulic pressure medium in its in called so that the piston valve 47 according to F i g. 3 F i g. 4 left position is held as the chamber is moved to the right to open the annular channel 39 α to 76 via the lines 77 and 62 with the control, so that the pressure medium is connected via the control line 60 line 40, which is constantly under the in

41 and the line 39 to the low-pressure chamber 36, the front pressure medium springs 20 a, 20 b can flow away until the frame 10 has its condensed pressure. The opposite end face has reached the structurally provided height position, at which the piston valve 65 is via a line 78, which is the control lever 43 in its from FIG. 3 can be seen indirectly at the borrowed central position, which is designed in a known manner. The hydraulic brake system is connected to the springs 52 and 65, and valve chambers 56 and 57 containing 53 stand a chamber 79 with the pressure of the brake fluid for draining off leakage oil to the low-pressure chamber 36. When applying a strong brake via discharge lines 58 and 59 in connection. force is the considerable back pressure in the chamber

76 and the piston valve 65 moved to the right (according to FIG. 4) in order to connect the lines 61 and 62 and the lines 64 and 63 to one another. The pressure medium is now fed directly to the front pressure medium springs 20 α and 20 b , while part of the pressure medium is drained from the rear pressure medium springs 20 c and 2Qd. This change in pressure takes place essentially simultaneously with the actuation of the brake, so that an upward force is applied to the front end of the vehicle, which counteracts the downward pitching movement. When the vehicle brakes are released, the pressure prevailing in the chamber 76 immediately moves the piston valve 65 to the left, whereby the lines 61 and 64 are shut off again, so that further changes in the height of the vehicle frame are prevented. The valve devices 32 and 33 then have the effect, in the manner already described, that the normal position of the frame is restored.

Furthermore, a device 80, 86 is provided to prevent the valve devices 32 and 33 from influencing the position of the vehicle during the braking process. The valve parts of this device, designed as electromagnetic valves 80, are preferably arranged within the main housing of the valve devices 32 and 33 and are shown in FIG. 3 shown. When energized, an electromagnet 81 attracts a valve plug 82 which protrudes into the control line 41a and closes this control line when the electromagnet 81 is de-energized, counter to the force of a spring 83, so that the pressure medium can flow through the control line 41a. The electromagnet 81 is with the in F i g. 4 with the designated 85 ignition switch of the vehicle connected in series. In addition, a switch 86, which is opened when the pressure of the brake fluid is applied to the chamber 79, is connected in series with the ignition switch 85, the electromagnet 80 and the battery 87. This circuit ensures that the electromagnets 81 are switched on when the ignition switch 85 is closed, so that the valve devices 32, 33 are operational. However, during the actuation of the brakes, the switch 86 is opened, whereby the electromagnets 81 are switched off so that the valve plugs 82 can shut off the control lines 40 a and 41 a from the associated valve devices 32 and 33 and the pressure medium springs 20 α, 20 δ, 20 c and 20 d are only exposed to the influence of the valve 60 for preventing nodding movements.

The arrangement of the ignition switch 85 in the circuit of the electromagnet 81 is also a Control of the height of the frame 10 in the event that the vehicle is parked or prevented is unattended. This is important because it has been shown that because of the novelty of with vehicles equipped with a leveling system there is a risk of people being parked Vehicles carry out experiments, wherein the pressure accumulator 31 is emptied so that the vehicle adjusts to a very low height when there is no guard. Shut-off valves Similar to the solenoid valve 80 can also be in the lines 40 and 41 in the vicinity of the cylinder 21 (Fig. 4) be switched on to avoid an unintentional To prevent actuation of this part of the system when the ignition is switched off.

The system described causes during braking at a relatively high driving speed that the front end of the vehicle rises slightly while the rear end of the vehicle lowers slightly; this is a reversal of the processes that usually occur during braking of a vehicle play. This gives the driver a sense of security and helps to keep the driver in his seat during sudden braking.

Since a strong brake pressure must be applied to the normally in the chamber 76 To overcome the prevailing pressure, the pressure normally applied to the brakes is sufficient is, while the vehicle od at an intersection. The like. Is stationary, not off to the piston valve 65 to move. The device for preventing nodding movements during braking thus comes only becomes effective when the full brake pressure is applied. If necessary, according to 4 a spring 69α can be provided to ensure that a predetermined Bremsdrußk must be applied before the device for Preventing nodding movements comes into play.

Instead of the valve device 32 at the front end of the vehicle, a manually operated Valve may be provided to reduce the cost of the system. On most passenger cars Such an arrangement is sufficient, because additional items are usually used in passenger vehicles Loads housed in the trunk or on the back seat so that they are mainly above the Take effect on the rear axle.

Claims (6)

Patent claims: 1. Stabilization device on motor vehicles to prevent nodding movements when braking, in which hydraulic-pneumatic springs are arranged between the vehicle frame and at least the rear wheel axle and a valve device, which works as a function of the actuation of the hydraulic vehicle brake, is provided for controlling the connecting line between the pressure medium springs and a pressure source is to control the vertical distance between the vehicle frame and the vehicle axle with the aid of the pressure medium springs, characterized in that the valve device (60) is a valve element (65) which can be acted upon in a known manner on one side by the brake fluid pressure (line 78) and is pretensioned in the opposite direction. which, when displaced by the brake fluid pressure, connects the pressure medium springs (20 c, 20 d) of the rear wheel axle (17) to a low-pressure chamber (36). 2. Stabilization device according to claim 1, wherein the vehicle frame at both the The front and rear axles are supported by pressure medium springs, characterized in that that the valve device (60) operating as a function of the brake fluid pressure when a predetermined one is exceeded Pressure value simultaneously with the relief of the pressure medium springs (20c, 2Od) of the rear wheel Axis (17) connects the pressure medium springs (20 a, 20 b) of the front wheel axle with the pressure source (31) in a manner known per se. 3. Stabilization device according to claim 1 or 2, in which depending on deviations valve devices responding to the normal horizontal height of the vehicle frame are provided to the line connection between the Druckmittelfedem and to control a pressure medium source, characterized by one when responding as a function the valve device (60) operating from the brake fluid pressure device (80, 86) for eliminating the influence the valve devices (32, 33) controlling the horizontal height of the frame during the braking period. 4. Stabilizing device according to claim 3, characterized in that each in the Pressure medium line between pressure medium spring (20) and the associated, the horizontal height the frame controlling valve device (32, 33) is provided with an electromagnetic valve (80), its circuit depending on the speak of the valve device (60) that can be actuated by the brake fluid pressure. 5. Stabilizing device according to claim 4, characterized in that the solenoid valve (80) is in the closed position when de-energized and its circuit in series with the ignition switch (85) of the vehicle and one when the brake fluid pressure rises is at a predetermined value opening switch (86). 6. Stabilizing device according to claim 3 to 5, characterized in that the horizontal Valve devices (32, 33) controlling the height of the vehicle frame to the same Pressure sources (31, 36) such as the valve device that operates as a function of the brake fluid pressure (60) are connected. Considered publications:
German Patent Nos. 801423, 928 933, 067; German Auslegeschrift No. 1 006 277;
German utility model No. 1 685 217;
U.S. Patent No. 2,184,202. 1 sheet of drawings 809 537/359 3. 68 © Bundesdruckerei Berlin