Patent Application
20220227196
The disclosure relates to an electronically open-loop or closed-loop controlled air spring system with a compressed air supply for height regulation of a vehicle, an air spring installation with such an air spring system, and to a method for the height regulation of a vehicle.
An air spring system is used in vehicles of all types, in particular for the height regulation of the vehicle, that is to say for the regulation of the spacing between the vehicle axle and the vehicle body. Said air spring system usually comprises a reservoir which provides compressed air from a compressed air supply system which is connected upstream of the air spring system, and, in addition, a number of air spring valves which are connected pneumatically to a common line (gallery), and subsequently, in a manner which is assigned to the former, a corresponding number of air springs. Here, the air springs as a rule comprise a number of air bellows which, as the filling increases, can lift the vehicle body and, as the filling decreases, can correspondingly lower it.
A compressed air supply system for use in conjunction with an air spring system, for example in an air spring installation, is operated by way of compressed air from a compressed air feed, for example within a pressure level of from 5 to 20 bar. The compressed air is made available by way of an air compressor (compressor) of the compressed air feed. The compressed air feed is connected pneumatically to a compressed air connector for the supply of the air spring system. In order to ensure long term operation of the compressed air supply system, it additionally comprises an air dryer, by way of which the compressed air is to be dried. As a result, the accumulation of moisture in the air spring installation is avoided, which is conducive to the protection of the air spring installation against defects.
In the case of a growing spacing between the vehicle axle and the vehicle body or the ground clearance, the spring deflections become longer, and even relatively great ground bumps can be overcome in this way, without contact with the vehicle body occurring. Systems of this type are used in off road vehicles and sport utility vehicles (SUVs). In the case of SUVs, in particular, it is desirable in the case of high performance engines to firstly provide the vehicle with a comparatively low ground clearance for high speeds on road and secondly to provide it with a comparatively great ground clearance for off roading. It is therefore desirable firstly for a change in the ground clearance to be implemented as rapidly as possible, which increases the requirements with regard to the performance of the compressed air supply system, and secondly it is desirable for a change in the ground clearance to be implemented, without it being necessary for the compressed air supply system to be operated permanently; in addition, the change in the ground clearance desirably takes place as far as possible without graduations which are perceptible to the vehicle driver. Furthermore, it would be desirable for it to be possible for the change in the ground clearance to be adapted individually for the front axle and the rear axle and/or for individual air springs, in order for it to be possible, for example, for a (nonuniform) loading of the vehicle or the like to be compensated for.
DE 10 2005 030 467 B4 has disclosed the air spring system, mentioned at the outset, for a height regulation of a vehicle with air springs, by way of which height regulation a predefined spacing of the vehicle cell from the vehicle axle can be maintained by way of the air springs being filled from a compressed air store or being emptied in a manner which is dependent on the vehicle loading. At least one central aerating valve is provided for the supply of the air bellows valves, which are assigned to the air bellows of the front axle (VA) and the rear axle (HA), with compressed air from a compressed air store. In order for uniform lifting and/or lowering to be achieved, the air bellows valves which are assigned to the air spring bellows on the front axle and the rear axle are loaded with a relatively high pulse frequency. Switching over of the central aerating valve cannot be achieved by way of the relatively high pulse frequency. Rather, in order to ensure an identical height regulation on the front axle and the rear axle, the invention provides a throttle with an adjustable or constant flow cross section, and the central aerating valve and a central venting valve. The throttle and valves are then intended to compensate for a different pressure build up time or pressure dissipation time in the air bellows of the air springs of the front axle and the rear axle. An air spring system of this type can still be improved.
The abovementioned solution requires, in particular, an increased structural complexity, that is to say the solution provides the use of two additional valves and a flow resistance element in the form of a throttle with a flow cross section which is preferably even variable.
In an embodiment, the present disclosure provides an electronically open-loop or closed-loop controlled air spring system with a compressed air supply for height regulation of a vehicle. The air spring system includes a number of air springs and a reservoir for the storage of compressed air, a number of switching valves for height regulation, and a controller configured to actuate the number of switching valves. The at least one switching valve is actuated with a number of sequential switching periods and switches over in a switching period, between a first switching state with an open valve state and a second switching state with a closed valve state, the switching period of the number of sequential shifting periods having the open valve state and the closed valve state. The controller is configured to set a speed for a height change of the height regulation. The setting of the speed takes place via an open/closed parameter, via which an open proportion of the open valve state and/or a closed proportion of the closed valve state in the switching period can be specified.
Subject matter of the present disclosure will be described in even greater detail below based on the exemplary figures. All features described and/or illustrated herein can be used alone or combined in different combinations. The features and advantages of various embodiments will become apparent by reading the following detailed description with reference to the attached drawings, which illustrate the following:
The present disclosure provides an apparatus and a method which are improved with regard to the prior art. In particular, an alternative solution to the prior art is specified, which alternative solution not only eliminates the disadvantages which result from an increased structural complexity, but rather also achieves the height regulation of the vehicle in an improved way.
The disclosure proceeds from the observation that the raising speed, out of the reservoir in the case of the height regulation of the vehicle, is dependent, for example, on the loading of the vehicle, the available pressure in the reservoir, the effective valve cross sections of the valves which are used, the counter-pressure of the air springs and more of that type. The result of this is that the experience of the height regulation of the vehicle, in particular the raising speed, changes for a driver in a manner which is dependent on the abovementioned factors. An experience of the height regulation as a constant process therefore does not normally take place.
It is admittedly fundamentally known, as described at the outset, that the air bellows valves which are assigned to the air spring bellows on the front axle and the rear axle are loaded with a relatively high pulse frequency.
A closed-loop controlled air volumetric flow can be generated in the case of the height regulation of the vehicle by means of pulsed actuation of a switching valve or a number of switching valves. Said closed-loop controlled air volumetric flow can then be fed to the air springs of the air spring system, as a result of which a more uniform raising speed and therefore a more uniform experience of the height regulation of the vehicle by way of the driver are made possible.
In contrast, the present disclosure has recognized that the setting of the speed for a height change of the height regulation, in particular raising speed and/or lowering speed, takes place in an advantageous way, in particular, via an open/closed parameter. The open/closed parameter is formed from a ratio of an open proportion of the open valve state to a closed proportion of the closed valve state in a switching period, during a sequence of sequential switching periods during the height regulation of the vehicle.
In this context, the ratio of open proportion to closed proportion of the switching valve denotes, for example, two consecutive time intervals during a switching period, a first time interval describing the switching valve in the open state, and a second time interval describing the switching valve in the following closed state. An open/closed parameter of the switching valve can then be derived from said ratio, which open/closed parameter in a particularly advantageous way defines the raising speed and/or the lowering speed in the case of the height regulation of the vehicle. The desired raising speed and/or the lowering speed can be set in a simple way by way of adaptation of the open/closed parameter. This can take place in such a way that, in the case of a desired reduction of the raising speed, a lower ratio is selected. In particular, the open proportion of the switching valve in a switching period in relation to the closed proportion of the switching valve in said switching period can be reduced. In the case of a desired increase of the raising speed, the open proportion of the switching valve in a switching period is to be increased correspondingly, in relation to the closed proportion of the switching valve in said switching period.
Said ratios apply identically in the case of a setting of the lowering speed. For the case where, for example, the lowering speed is to be reduced, in particular, the open proportion of the switching valve in a switching period in relation to the closed proportion of the switching valve in said switching period is likewise to be reduced.
The above-described switching pattern is advantageously to be understood as a pulse width modulation which, by way of a modulated pulse width, brings about actual, preferably complete, opening and closing of the switching valve. As a result, a desired air volumetric flow is then generated, and the resulting raising speed and/or lowering speed of the height regulation is controlled in this way. In other words, the pulse width modulation is designed in such a way that it is ensured that the switching valve both opens completely and closes completely within a switching period. The open proportion of the open valve state and the closed proportion of the closed valve state in a switching period of a sequence of sequential switching periods are then defined in accordance with the open/closed parameter. In this respect, a switching valve of this type is also called a switching valve which is switched in an actuated manner in the following text.
In accordance with the concept of the disclosure, it is additionally advantageously provided for the height regulation of the vehicle to be implemented without additional components. That is to say, in contrast to the prior art, the concept of the disclosure leads not only advantageously to a less expensive height regulation of the vehicle by way of further components being saved, but rather likewise leads as a consequence to a solution which requires less maintenance and is more fail-safe.
By way of an actuation of suitable switching valves, for example by way of an actuation of venting valves, the height regulation of the vehicle can be transferred in an analogous manner to the lowering operation of the vehicle. In addition, an actuation of a switching valve and/or a number of switching valves is required in a manner which is dependent on the specific embodiment. The following developments are intended to be correspondingly applicable to one switching valve and/or a number of switching valves.
Furthermore, the disclosure provides an air spring installation with an air spring system according to the disclosure and comprising, furthermore, a compressed air supply system, with a compressed air feed, a compressed air connector, a main pneumatic line between the compressed air feed and the compressed air connector, which main pneumatic line comprises an air dryer, and a compressed air supply line, between the compressed air connector and the air spring system.
Furthermore, the air spring installation comprises a venting connector and a venting line between the compressed air feed and the venting connector, which venting line comprises a venting valve, the main pneumatic line and/or the compressed air supply line comprising at least one throttle or flow resistance element of that type.
Furthermore, it is provided that the venting valve can be actuated, and the controller is configured, furthermore, for the actuation of the venting valve and for the setting of the lowering speed of the height regulation, a setting of the lowering speed of the height regulation likewise taking place via the open/closed parameter. In addition, it is provided that the throttle or flow resistance element of that type is configured for the smoothing of the raising speed and/or the lowering speed of the height regulation of the vehicle. Here, the advantages of the air spring system are advantageously transferred to the air spring installation.
In particular, in one development, the at least one throttle or flow resistance element of that type is advantageously arranged in the main pneumatic line between the air dryer and the compressed air connector, and/or is arranged in the compressed air supply line between the compressed air connector and the air spring system.
It is advantageously provided that the speed of the height change of the height regulation is a raising speed or a lowering speed, the controller being configured to set the raising speed and/or the lowering speed. Specifically, this means that both a more uniform raising speed and a more uniform lowering speed are advantageously achieved, and therefore a more uniform experience of the height regulation of the vehicle by way of the driver is made possible.
It is provided within the context of one preferred development that the height regulation of the vehicle takes place within a permissible height interval, between a minimum height and a maximum height. Specifically, this means that the value range of the height regulation is restricted to values which are appropriate in terms of technology and driving dynamics. In this way, an incorrect operation by way of the driver of the vehicle is advantageously avoided a priori.
Furthermore, it is advantageously provided that the dimension of the open/closed parameter can be specified in percent. Scaling of the open/closed parameter to a percent scale makes, in particular, an intuitive setting of a desired raising speed in the case of the height regulation of the vehicle by the driver possible or, in the case of an automatic setting of the raising speed by means of a control device or the like, makes a simple handling of the open/closed parameter in terms of program technology possible.
In addition, it is provided in one development that the open/closed parameter can assume any desired value in the value range between 0% and 100%. As a consequence, a value of 0% then forms the lower limit case of a continuously closed switching valve of a number of switching valves and, in an analogous manner, the limit case of a continuously closed switching valve of a number of switching valves is represented by way of a value of 100%. Specifically, this means that the state space of the switching valve is described completely by way of the open/closed parameter in the value range between 0% and 100%. Therefore, a simple possibility is advantageously provided of firstly modulating the pulse width of the open/closed parameter, in order to adapt it to the respective driving situation, and secondly, for example, to keep the switching valve closed as long as no height adaptation of the vehicle is required.
In this context, however, it is provided in one development for, in particular, three clearly delimited and technologically particularly advantageous value ranges to be defined. To this end, it is provided in a first development that the open/closed parameter assumes, in particular, a value from the value range between 25% and 35%. Furthermore, it is provided in a second development that the open/closed parameter assumes, in particular, a value from the value range between 45% and 55%. In addition, it is provided in a third development that the open/closed parameter assumes, in particular, a value from the value range between 65% and 75%.
It can be seen from the three abovementioned preferred value ranges that the first value range between 25% and 35% corresponds with a slow speed for a height change of the height regulation, in particular raising speed and/or lowering speed, the second value range between 450 and 55° corresponds with a medium speed for a height change of the height regulation, in particular standard raising speed and/or standard lowering speed, and the third value range between 65% and 55% corresponds with a rapid speed for a height change of the height regulation, in particular raising speed and/or lowering speed, relative to the two first-mentioned value ranges. It is therefore advantageously possible for a preferred raising speed and/or lowering speed to be defined, in a manual or automated manner, which raising speed and/or lowering speed takes into consideration boundary conditions which are relevant for the height adaptation of the vehicle, such as, for example, the available reservoir pressure, the vehicle loading, the current driving situation and the like, in a way which is particularly simple and intuitive to a vehicle driver. It is thus conceivable, for example, that a rapid raising speed is to be preferred in the case of a rapid transition from a paved tar road to an unpaved gravel track or the like.
It is provided within the context of one preferred development that the value of the open/closed parameter is variable during the height regulation of the vehicle out of the reservoir. Specifically, this means that the open/closed parameter can be adapted dynamically, in particular even during a running height regulation. It is therefore advantageously possible to react directly in terms of closed-loop control technology to variable boundary conditions which influence the speed for a height change of the height regulation, in particular the raising and/or lowering speed, such as, for example, decreasing reservoir pressure. In addition, this development is advantageous as soon as the underlying surface conditions change in rapid succession during driving and the height regulation takes place, in particular, in an automatic manner, since, during a running raising and/or lowering operation, said operation can then be adapted in such a way that the rapidly changing underlying surface conditions can be represented, for example by way of a mean value between that height level of the vehicle which is preferred in each case for a certain underlying surface.
In particular, it is provided in one development that the raising speed is constant in the case of the height regulation of the vehicle out of the reservoir. This means, in particular, that the raising speed and/or the lowering speed makes/makes an infinitely variable height regulation of the vehicle possible, with acknowledgement in terms of closed-loop control technology of restrictive boundary conditions such as available reservoir pressure and the like. This results in the advantage that the height regulation takes place without perceptible graduations for a driver, that is to say is perceived over time neither as accelerating nor as decelerating, in particular.
A further preferred development provides that the speed for a height change of the height regulation, in particular the raising speed and/or the lowering speed, takes place via an evaluation of height level values within the permissible height interval. Specifically, this means that the speed for a height change of the height regulation, in particular raising speed and/or the lowering speed, is set via a constant time-distance ratio if a constant raising speed and/or lowering speed are/is desired. That is to say, the height increment which is measured or determined in some other way is traveled in each case within identical time increments. This results in the advantage that an alternative closed-loop control approach is available in the case of failure of the sensor system which as a rule closed-loop controls the height regulation of the vehicle out of the reservoir.
It is provided in one development that the controller is configured to generate a constant air volumetric flow in the case of the height regulation of the vehicle out of the reservoir. A constant air volumetric flow in the direction of the air springs is constituting for a constant raising speed; therefore, the constant air volumetric flow results directly in an infinitely variable raising and/or lowering movement of the vehicle, which movement ideally cannot be perceived by the driver.
In addition, it is provided in one particularly preferred development that the frequency of the switching period of the actuation of the at least one switching valve of the number of switching valves is defined in such a way that the height regulation of the vehicle out of the reservoir takes place uniformly, in particular without perceptible graduations. Specifically, this means that, if the frequency of the switching period is selected to be too small, that is to say if the opening and closing of the switching valve takes place too slowly, the result is a step-shaped raising and/or lowering profile which is clearly perceptible to the driver. This undesired behavior can be avoided in a particularly advantageous way, that is to say in a way which is simple in terms of closed-loop control technology, by way of a suitable selection of the frequency of the switching period.
In the context of the above development, it is provided that the frequency of the switching period is selected, in particular, from a value range, comprising the values of greater than or equal to 5 Hz and less than or equal to 20 Hz. The value of the frequency of the switching period lies, in particular, in this advantageous value range, since a perceivable graduation of the raising and/or lowering operation is brought about at a frequency below 5 Hz, which graduation is smoothed increasingly as the frequency increases. Therefore, there is no longer an improvement which can be perceived by the driver for values above 20 Hz. In contrast, an increasing frequency brings about increasing mechanical loading of the switching valve of the number of switching valves. Therefore, the frequency advantageously lies within a range between 5 Hz and 20 Hz.
In particular, it is provided in one development that the speed for a height change of the height regulation, in particular raising speed and/or lowering speed, can be set differently on a front axle and/or a rear axle in the case of the height regulation of the vehicle out of the reservoir. Specifically, this means that a dynamic height compensation of the vehicle is made possible in accordance with said development. Vehicles as a rule have a nonuniform weight distribution in the loaded and in the unloaded state, which nonuniform weight distribution has a different effect on the front axle than on the rear axle. If this circumstance is not taken into account, the result is differently rapid raising and lowering on the front axle than the rear axle in a manner which is dependent on the loading and the like. As a result of the specific development, this problem is solved in an advantageous way by way of differently adjustable raising speeds and/or lowering speeds on the axles.
It is provided in a further preferred development that the speed for a height change of the height regulation, in particular raising speed and/or the lowering speed, can be set individually for each air spring of the number of air springs in the case of the height regulation of the vehicle out of the reservoir. Specifically, this means that the speed for a height change of the height regulation, in particular raising speed and/or the lowering speed, can be set individually for each air spring. In particular, in the case of off road vehicles which make it necessary for in some cases significant height differences between the axles, but also between the individual wheels, relative to the vehicle body to be compensated for, advantages result from said development. For example, it can become necessary for one of the front wheels to be raised and/or lowered as rapidly as possible relative to one of the rear wheels, in order to effectively prevent grounding of the vehicle.
In particular, it is provided in one development that the number of switching valves is a number of bellows valves which are switched in an actuated manner, configured for the setting of the speed for a height change of the height regulation, in particular raising speed and/or the lowering speed of the height regulation of the vehicle. Specifically, this means that, in particular, the bellows valves of the individual air springs are switched in an actuated manner here, which results in the advantage that the raising and lowering operation of the vehicle can be set individually for each air spring, to be precise in such a way that the raising and lowering operation is not perceptible to the driver and, in particular, takes place without perceptible graduations.
It is provided within the context of one preferred development that the at least one switching valve of the number of switching valves is a reservoir valve which is switched in an actuated manner, configured for the setting of the raising speed of the height regulation of the vehicle. Specifically, this means that only the reservoir valve is switched in an actuated manner, in order to achieve uniform raising of the vehicle, in particular without perceptible graduations. Therefore, the complexity in terms of closed-loop control technology is advantageously reduced, since only one switching valve, the reservoir valve, has to be switched in an actuated manner.
In particular, it is provided in one development that the speed is a lowering speed, and the height regulation of the vehicle takes place via venting of the compressed air supply, preferably the compressed air supply system, a number of venting valves being switched in an actuated manner. Specifically, this means that at least one venting valve of the compressed air supply system is switched in an actuated manner, in order to achieve uniform lowering of the vehicle, in particular without perceptible graduations. Therefore, the complexity in terms of closed-loop control technology is advantageously reduced, since only a venting valve which is already present has to be switched in an actuated manner for the setting of the lowering speed.
It is provided within the context of one preferred development that the air dryer of the air spring installation has, furthermore, a volume, the volume of the air dryer being configured as a buffer volume, for the smoothing of the raising speed and/or the lowering speed of the height regulation of the vehicle. By virtue of the fact that the air dryer housing acts as an additional flow resistance which brings about a tolerable pressure drop in the air volumetric flow, damping of the fluctuation values which are associated with the flow is advantageously produced. As a result, the raising and/or lowering movement takes place, in particular, more uniformly in the case of the height regulation of the vehicle.
In addition, it is provided in one preferred development of the air spring installation that the air spring installation comprises, furthermore, a venting connector, a venting line between the compressed air connector and the venting connector, which venting line comprises a venting valve, the main pneumatic line comprising, furthermore, a check valve between the air dryer and the compressed air connector, for shutting off of the components of the compressed air supply system in the direction of the air dryer, it being provided, in particular, that the venting valve can be actuated, and the controller being configured, furthermore, for the actuation of the venting valve and for the setting of the lowering speed of the height regulation, a setting of the lowering speed of the height regulation likewise taking place via the open/closed parameter. It is provided, furthermore, that the compressed air supply line comprises a throttle or flow resistance element of that type, the throttle or flow resistance element of that type being configured for smoothing of the raising speed and/or the lowering speed of the height regulation of the vehicle.
In this way, firstly, the advantages which result by way of an actuation of the switching valves which are involved in the raising operation can be transferred in a simple way to the lowering operation, by way of an actuation of the venting valve of the compressed air supply system. Secondly, it is advantageously possible, by way of the use of a throttle or flow resistance element of that type, arranged in accordance with the abovementioned embodiment, to smooth the controlled air volumetric flow in a particularly advantageous way, which air volumetric flow is generated by way of the controller of the switching valve of a number of switching valves. That is to say, fluctuation values in pressure, speed or the like of the air volumetric flow which are associated with the generation of precisely this air volumetric flow are smoothed or damped effectively and particularly advantageously by way of the provision of a throttle or flow resistance element of that type, with the result that the height regulation of the vehicle is perceived to be correspondingly more uniform by the driver.
In addition, it is provided in one alternative development that the main pneumatic line and the compressed air supply line are continuous between the air dryer and the air spring system, that is to say are free, in particular, from flow resistance elements. This alternative development has recognized in a particularly advantageous way that the volume of the air dryer can likewise assume the function of the throttle which is used in the first development. That is to say, the volume of the air dryer can be used as a buffer volume, in order to damp the fluctuation values which are associated with the generated air volumetric flow. In this way, the height regulation of the vehicle is likewise perceived to be more uniform by the driver in comparison with an embodiment without a measure of this type. Furthermore, said development results in the advantage that the throttle or flow resistance element of that type which is otherwise necessary is redundant. This results in an advantage with regard to complexity, costs and maintenance in comparison with the other developments.
Embodiments will now be described in the following text on the basis of the drawing. Said drawing is not necessarily intended to illustrate the embodiments to scale; rather, where it is expedient for explanation purposes, the drawing is configured in a diagrammatic and/or slightly distorted form. Reference is made to the relevant prior art with regard to supplements to the teachings which can be seen directly from the drawing. It is to be taken into consideration here that a wide variety of modifications and amendments relating to the shape and the detail of one embodiment can be performed, without departing from the general concept of the disclosure. The general concept of the disclosure is not restricted to the exact shape or the detail of the preferred embodiments which are described and shown in the following. In the case of specified dimensional ranges, values which lie within said limits are also intended to be disclosed as limit values, and are intended to be capable of being used and claimed as desired. For the sake of simplicity, identical designations are used in the following text for identical or similar parts or parts with an identical or similar function.
Furthermore, the air spring system 100 comprises a reservoir 120 for the storage of compressed air DL and, connected pneumatically to said reservoir 120, once again a switching valve SV, in the present case in the form of the reservoir valve 130.R, in particular likewise a solenoid valve. In addition, the components of the air spring system 100 are connected to one another pneumatically via a gallery 160 which, on the one side via a compressed air supply line 240, conducts compressed air DL from the compressed air supply device 200 directly to the individual air springs 110 or their switching valves SV, that is to say here the bellows valves 130.B, and, on the other side, conducts compressed air DL for storage to the reservoir 120 or once again to its switching valve SV, that is to say the reservoir valve 130.R here, for the purpose of storage of the provided compressed air DL. In addition, in the case of operation of the air spring system 100 out of the reservoir 120, the gallery 160 likewise conducts the compressed air DL which is output by the reservoir 120 to the air springs 110 or their switching valves SV, that is to say their bellows valves 130.B here.
Here, the compressed air supply device 200 which is shown comprises first of all an air feed 0.1, followed by a filter 0, the air which is sucked in being compressed in an air compressor (compressor) 210, in order subsequently to be fed via a compressed air feed 1 to an air dryer 220 which is situated downstream in a main pneumatic line 250. Subsequently, the compressed air flows through a throttle 230 or flow resistance element of that type which acts as a regenerator throttle. Further downstream, the compressed air supply installation 200 is connected pneumatically at a compressed air connector 2 via a compressed air supply line 240 to the air spring system 100 or its gallery 160. In the present case, in addition, the compressed air supply device 200 comprises a venting line 260 between the compressed air feed 1 and the venting connector 3 and, arranged in said venting line 260, a venting valve 130.3 which is in turn configured, in particular, as a solenoid valve.
Here, the operating behavior of the air spring system 100 is provided via a controller (ECU) 140. Via said controller 140, firstly the switching valves SV of the air springs 110, in particular bellows valves 130.B, and secondly the switching valve 130.R of the reservoir 120 are actuated. The actuation of the bellows valves 130.B of the air springs 110 can advantageously take place in such a way that either all the air springs 110 of the vehicle 150 are addressed at the same time, but it is also possible that the bellows valves 130.B which are assigned to the front axle VA and those which are assigned to the rear axle HA are actuated differently, in order, for example, to compensate for a loading of the vehicle 150. Furthermore, the possibility also arises of individual air springs 110 of the air spring system 100 being addressed individually, in order for it to be possible to react in terms of control technology to particularly impassable terrain. For this purpose, the air springs 110 can be actuated individually or jointly in a synchronous manner, in order to perform a corresponding height regulation HR of a vehicle 150 within a height interval H, characterized by a minimum height H0 and a maximum height H1.
The number of switching valves 130 shown in
Furthermore,
Lowering of the vehicle 150 during the height regulation HR, that is to say setting of the lowering speed Us, preferably takes place in the present case via the compressed air supply system 200. To this end, the controller 140 is configured analogously to actuate the venting valve 130.E, the lowering speed US likewise being adjustable in an analogous way via the open/closed parameter AZP. Here, the throttle 230 or flow resistance element SWE of that type, in the present case arranged in the main pneumatic line 250, has a smoothing action on the raising and/or lowering operation. As an alternative however, raising and lowering of the vehicle 150 can also take place exclusively via an actuation of the bellows valves 130.B and, assigned to the latter, the air springs 110.
The actuation of the at least one switching valve SV, that is to say, in particular, of a bellows valve 130.B and/or a reservoir valve 130.R and/or a venting valve 130.E, of the number of switching valves 130 by way of the controller 140 can additionally take place in a pulsed manner. A pulsed actuation of this type is advantageously to be understood to mean a pulse width modulation PWM which brings about actual, preferably complete opening A and closing Z of the at least one switching valve SV by way of a modulated pulse width PW. As a result, a desired air volumetric flow LV is then generated, and in this way the resulting raising speed UH and/or lowering speed US of the height regulation HR are/is controlled. That is to say, the pulse width modulation PWM is designed in such a way that it is ensured that the at least one switching valve SV both completely opens A and completely closes Z within a switching period P.
In this regard,
In the embodiment of
In the embodiment of
In a further embodiment (not shown here), the first and the second throttle 230.1, 230.2 can also be arranged in the main pneumatic line 250 and the compressed air supply line 240.
In the following text,
To this end,
In the present case, in addition,
Furthermore, it is provided in a first alternative embodiment that the throttle 230 or flow resistance element of that type is arranged in the gallery 160, in order to assume there an identical function as described above for the case of the arrangement in the compressed air supply line 240. Furthermore, it is provided in a second alternative embodiment that the throttle 230 or flow resistance element of that type (and the check valve 280) are dispensed with completely and, for advantageous smoothing GL of the air volumetric flow, the air dryer 220 in the main pneumatic line 250 assumes the function of the throttle 230 in an identical manner. As a result of this measure, an additional component can be dispensed with, without having to accept losses in the advantageous function.
It can be seen directly from
In a view A, using the example of the rear axle HA and the front axle VA for the operation of the height regulation HR,
In the present case, in the view A,
In the view A,
In each case in the view A,
According to
The actuation ANS of the at least one switching valve SV, that is to say, in particular, of a bellows valve 130.B and/or a reservoir valve 130.R and/or a venting valve 130.E, of the number of switching valves 130 can also take place in a pulsed manner here. In particular, the actuation ANS can take place via pulse width modulation PWM, for the implementation of the switching period P of the number of sequential switching periods PN.
While subject matter of the present disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. Any statement made herein characterizing the invention is also to be considered illustrative or exemplary and not restrictive as the invention is defined by the claims. It will be understood that changes and modifications may be made, by those of ordinary skill in the art, within the scope of the following claims, which may include any combination of features from different embodiments described above.
The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 114 150.8 | May 2019 | DE | national |
| 10 2019 129 371.5 | Oct 2019 | DE | national |
This application is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2020/063266, filed on May 13, 2020, and claims benefit to German Patent Application No. DE 10 2019 114 150.8, filed on May 27, 2019 and to German Patent Application No. DE 10 2019 129 371.5, filed on Oct. 30, 2019. The International Application was published in German on Dec. 3, 2020 as WO/2020/239440 A1 under PCT Article 21(2).
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/063266 | 5/13/2020 | WO | 00 |
