System and method for stabilizing a cab of a motor vehicle
The system stabilizes motor vehicle cabs by controlling air spring dynamics through a valve system that adjusts air supply and discharge based on tilting and parked conditions, addressing instability and discomfort issues in existing cab suspension systems.
Patent Information
- Application Number
- PCT/SE2024/050507
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-05-23
- Publication Date
- 2025-11-27
AI Technical Summary
Existing cab suspension systems in motor vehicles using air springs can lead to rocking and swaying motions during tilting, creating unsafe and uncomfortable conditions due to the counterforces generated by the air springs, especially when exposed to wind gusts or tilting, which affect the cab's center of gravity and stability.
A system with integrated air springs and a control valve that adjusts air supply based on the tilting and parked conditions of the cab, preventing undesired air feeding and allowing controlled air discharge to stabilize the cab, using a determination device to switch between states and potentially incorporating contraction limitation devices to maintain a stable static position.
The system prevents rocking and swaying motions, ensuring a smooth and secure tilting process and reducing cab shaking from wind, thereby enhancing safety and comfort during parking and tilting.
Smart Images
Figure SE2024050507_27112025_PF_FP_ABST
Abstract
Description
[0001] SYSTEM AND METHOD FOR STABILIZING A CAB OF A MOTOR VEHICLE
[0002] Description
[0003] The invention concerns a system for stabilizing a cab of a motor vehicle and a method for stabilizing a cab of a motor vehicle.
[0004] It is known to use air springs as cab suspension elements in motor vehicles. Depending on the kinematic of the front cab suspension (for instance with air springs arranged above a pivot point of the cab) a (for instance: internal) leveling system of the air spring may lead to a rocking and swaying motion of the cab, when the cab is being tilted. This is because the leveling system and the hydraulic cylinder of the tilting system work against each other. The counterforce of the air spring leads to an undefined position of the tilted cab concerning the center of gravity (COG) and the dead center. In addition, the counterforce can cause a falling back of the cab itself. This may result in an unpleasant and / or dangerous situation for the person tilting the cab.
[0005] Further, when passengers or truck drivers are resting in a parked truck with a cab suspension with air springs, relative winds from the bypassing traffic as well as gusts of wind rock and shake the cab and decrease the comfort for the passengers or truck drivers.
[0006] It is therefore an objective of the invention to provide a particularly improved technique for stabilizing a cab of a motor vehicle. Specifically, it is - for instance - an objective to provide a safer technique for tilting the cab and / or to provide a technique that increases comfort when parking the motor vehicle. In particular, it is an objective to provide a solution to use an internal leveling system, which also works smoothly, when tilting the cab and leads to a secure tilted position of the cab. In particular, the technical solution should also reduce the shaking of the cab due to relative winds to improve the resting comfort for truck drivers.
[0007] The objective is solved by the features of the independent claims. Advantageous further embodiments are specified in the dependent claims and the description.
[0008] According to a first general aspect of the invention, a system for stabilizing a cab of a motor vehicle is provided.
[0009] Preferably, the cab is a driver’s cab of a motor vehicle. However, it is also possible that the motor vehicle e. g. is an unmanned motor vehicle. Preferably, the motor vehicle is a utility vehicle.
[0010] The system comprises at least one air spring, an air storage, a fluid connection between the at least one air spring and the air storage. The system further comprises a valve.
[0011] The at least one air spring comprises a level control means. Preferably, the level control means comprises an air discharge valve. Optionally, the level control means is integrated into the at least one air spring.
[0012] The valve is arranged externally of the at least one air spring and is integrated into the fluid connection.
[0013] The valve is configured to be (e. g. selectively) switched into a first switching state and into a second switching state (e. g. dependent on a tilted condition of the cab and / or a parked condition of the motor vehicle).
[0014] In the first switching state an air supply from the air storage to the at least one air spring is enabled (e. g. allowed and / or facilitated). In the second switching state the air supply from the air storage to the at least one air spring is blocked (e. g. cut and / or closed and / or shut down).
[0015] Preferably, the system further comprises a determination device, wherein the determination device is configured to determine the tilted condition of the cab and / or the parked condition of the motor vehicle.
[0016] Advantageously, blocking the air supply in the second switching state may prevent an undesired feeding of air into the air spring during the tilting of the cab. Thus, a rocking and swaying motion of the cab may be prevented. Contrary, a calm and / or smooth and / or continuous tilting motion may be achieved. This may increase the ease of use and / or the operating safety of the tilting of the cab.
[0017] The level device may be embodied as an internal level device, which may be advantageous with regard to the package space (in particular compared to external level devices).
[0018] A further advantage may be seen in that the technique e. g. may be used in all kinematic setups of the front cab suspension in combination with an internal leveling system.
[0019] The technique enables a simple mechanical solution with least complexity and high robustness and a regulation of external valve with high flexibility and therefore an easy-to-integrate solution into existing infrastructure. Further, a shaking of the cab may be prevented, when the motor vehicle is parked. Contrary, a stable (e. g. steady) static position, which is not sensitive to relative winds and wind gusts, may be achieved, when parking. This may increase the comfort for a person resting in the cab.
[0020] In particular, the motor vehicle is a semi-autonomous or autonomous motor vehicle. The motor vehicle may comprise an electric machine and / or a combustion engine.
[0021] The air supply preferably is a pressurized air supply.
[0022] The level control means optionally may be configured to discharge air to an environment of the at least one air spring.
[0023] The valve may be activated, for example, by an (electric, pneumatic, hydraulic, etc.) impulse or a signal or may be manually operated. The regulation of the external valve may also be directly integrated into the tilting system (tilting pump, cab locks, etc.),
[0024] According to an embodiment, the valve may be configured to be switched into a third switching state (for instance dependent on the tilted condition of the cab and / or the parked condition of the motor vehicle). In the third switching state the air supply from the air storage to the at least one air spring may be blocked and an air discharge from the at least one air spring to an external environment of the valve may be enabled. Thereby, it is possible to switch the valve into the third switching state in order to actively discharge air comprised in the air valve. This may be advantageous, for instance, in order to empty the air valve at least partially, so as to achieve a stable static position during parking and / or during tilting.
[0025] According to an embodiment the control device may be configured to switch the valve into the second switching state or into the third switching state upon (e. g. caused by a) determination of the tilted condition and / or of the parked condition. For instance, it is possible that the control device receives a signal indicating that the cab is (or will shortly) be in the tilted condition and / or the vehicle is (or will shortly be) in the parked condition. Further, it is possible that the control device is adapted to automatically switch the valve into the second switching state or into the third switching state, when said signal is received. However, the control device may also be e. g. manually operated and / or e. g. impulse-controlled. Thereby, the ease-of-use, operating safety and / or comfort may be further increased.
[0026] According to an embodiment, the control device may be configured to switch the valve into the second switching state or into the third switching state to at least partially discharge air comprised in the at least one air spring (e. g. so that the at least one air spring does not contribute to and / or does not provide a counter force to a tilting force and / or so that the at least one air spring provides a stable static position of the cab). For instance, it is possible that the control device is adapted to actively discharge air from the air spring until the stable static position of the cab and / or the position, in which the at least one air spring does not contribute to and / or does not provide the counter force to the tilting force, is reached.
[0027] According to an embodiment, the control device may be configured to switch the valve into the second switching state or into the third switching state so as to at least partially (for instance substantially completely) contract the at least one air spring before a centre of gravity of the cab crosses a vertical plumb line through a pivot point of the cab (e. g. before the centre of gravity crosses a top dead centre). For instance, the time for tilting the cab from an untilted position to a position, in which the centre of gravity of the cab crosses the plumb vertical line may be previously known and / or stored on the control device. Further, the tilting velocity and / or length of a tilting trajectory may be previously known and / or stored on the control device. Further, an air flow rate of the at least one valve may be dimensioned and / or controlled by the control device such that an at least partial contraction of the at least one valve is achieved before the centre of gravity crosses the plumb line. This is in particular advantageous, because while the mass of the cab may work against the tilting force before the centre of gravity crosses the plumb line, this suddenly may change when the centre of gravity crosses the vertical plumb line (i. e. the mass of the cab may suddenly promote the tilting of the cab). By at least partially contracting the air spring before the crossing of the plumb line, a falling back of the cab may be prevented and / or reduced.
[0028] According to an embodiment, the at least one air spring may comprise a contraction limitation device (e. g. a bump stop and a counter element) integrated into the at least one air spring. In the second switching state or in the third switching state the contraction limitation device may limit the contraction of the at least one air spring (for instance such that the bump stop and the counter element contact each other). Preferably, the bump stop contacts (e. g. sits on top of) the counter element in the second switching state or in the third switching state. The contraction limitation device (e. g. the bump stop) may comprise a material e. g. of Polyurethane or elastomer or natural rubber. Thereby, a technically straightforward way of achieving the stable static position may be provided.
[0029] According to an embodiment, the level control means may be configured to discharge air comprised in the at least one air spring to an external environment of the at least one air spring so as to control a level position of the cab or of the motor vehicle. Thereby, it is possible that the level control means, which is provided in the air springs, is used to discharge air so as to achieve the stable static position and / or the calm tilting. This may reduce the technical effort, costs and / or construction space. According to an embodiment, the tilted condition may be determined (e. g. by the determination device) upon a tilting of the cab out of an untilted position of the cab. The untilted position may, for instance, be a substantially horizontal position and / or a driving position of the cab.
[0030] According to an embodiment, the determination device may further comprise a sensor element and / or a user input element. The sensor element may be configured to detect the tilted condition of the cab and / or the parked condition of the motor vehicle. For instance, the sensor element may comprise a position sensor and / or a contact switch. This may be a particularly convenient solution.
[0031] Alternatively or additionally, the determination device may be configured to determine the tilted condition of the cab and / or the parked condition of the motor vehicle upon a user input via the user input element. For instance, the user may indicate an intended tilting of the cab and / or an intended parking by pressing a button (for instance located in or at the cab). This may further reduce technical effort and / or costs.
[0032] According to an embodiment, in the second switching state, an air discharge from the at least one air spring to an external environment of the valve may be enabled or blocked.
[0033] According to an embodiment, the system may comprise a second fluid connection. The second fluid connection may fluidically connect the at least one air spring via the valve to an environment of the valve. In the first switching state an air discharge from the at least one air spring via the second fluid connection to the environment may be blocked and in the second switching state an air discharge from the at least one air spring via the second fluid connection to the environment may be enabled. The second fluid connection may be a separate fluid line that connects the at least one air spring (e. g. via a separate valve-outlet) to the valve. In the second switching state, the valve may be configured to discharge air comprised in the at least one air valve essentially in an unregulated and / or uncontrolled manner. Thereby, the stable static position and / or the calm motion of the cab may be achieved rapidly and / or with reduced technical effort.
[0034] According to an embodiment, the system may comprise a further fluid connection. The further fluid connection may fluidically connect the level control means via the valve to an environment of the valve. In the first switching state and in the third switching state, an air discharge from the at least one air spring via the level control means and via the further fluid connection to the environment may be enabled. Preferably, the control device as disclosed herein is configured to switch the valve in the second switching state upon detection of the tilted condition. Preferably, the control device as disclosed herein is configured to switch the valve in the third switching state upon detection of the parked condition. In the second switching state an air discharge from the at least one air spring via the level control means and via the further fluid connection to the environment may be blocked. The further fluid connection may be a separate fluid line that connects the at the level control means to the valve. In the first switching state and in the third switching state the valve may be configured to discharge air comprised in the at least one air valve essentially in a regulated and / or controlled manner, while in the second switching state a remaining air pressure may optionally prevail in the at least one air spring. The remaining air pressure may be desired in particular when tilting the cab while the air discharge from the at least one air spring may be desired when parking the vehicle.
[0035] According to an embodiment, the system may comprise a second fluid connection. The second fluid connection may fluidically connect the at least one air spring via the valve to an environment of the valve. In the first switching state and in the second switching state an air discharge from the at least one air spring via the second fluid connection to the environment may be blocked. In the third switching state an air discharge from the at least one air spring via the second fluid connection to the environment may enabled. Preferably, the control device as disclosed herein is configured to switch the valve in the second switching state upon detection of the tilted condition. Preferably, the control device as disclosed herein is configured to switch the valve in the third switching state upon detection of the parked condition. The second fluid connection may be a separate fluid line that connects the at least one air spring (e. g. via a separate valve-outlet) to the valve. In the third switching state, the valve may be configured to discharge air comprised in the at least one air valve essentially in an unregulated and / or uncontrolled manner.
[0036] The system may comprise a further fluid connection. The further fluid connection may fluidically connect the level control means via the valve to an environment of the valve. In the first switching state and in the second switching state an air discharge from the at least one air spring via the level control means and via the further fluid connection to the environment may be enabled. In the third switching state an air discharge from the at least one air spring via the level control means and via the further fluid connection to the environment may be blocked. In the first switching state and in the second switching state the valve may be configured to discharge air comprised in the at least one air valve essentially in a regulated and / or controlled manner. The further fluid connection may be a further separate fluid line that connects the at the level control means to the valve.
[0037] In the first switching state and in the second switching state the valve may be configured to discharge air comprised in the at least one air valve essentially in a regulated and / or controlled manner and optionally a remaining air pressure may prevail in the at least one air spring. The remaining air pressure may be desired in particular when tilting the cab while the air discharge from the at least one air spring may be desired when parking the vehicle. In the third switching state the valve may be configured to discharge air comprised in the at least one air valve essentially in an unregulated and / or uncontrolled manner. In particular when tilting the cab a regulated discharge of air and / or a remaining air pressure may be desired, while a rather abrupt air discharge may be desired when the vehicle is parked.
[0038] According to an embodiment, the valve may comprise a 3 / 2-valve, 3 / 3-valve, 4 / 2-valve, 4 / 3- valve or a 5 / 3-valve. However, these are just examples. Generally, any valve suitable to be configured as disclosed herein could be used.
[0039] Alternatively or additionally the air discharge valve may be integrated into the at least one air spring.
[0040] Alternatively or additionally the at least one air spring may be arranged (e. g. directly) above a pivot point of the cab.
[0041] Alternatively or additionally the at least one air spring may comprise two front air springs arranged opposite each other in width direction of the cab. Preferably, the at least one air spring may comprise two rear air springs arranged opposite each other in width direction of the cab.
[0042] According to a further general aspect, a motor vehicle (for instance a utility vehicle) is provided. The motor vehicle comprises a system as disclosed herein. The motor vehicle further comprises a cab. The at least one air spring supports the cab. Preferably, the motor vehicle further comprises a tilting device (for instance a tilting cylinder) for tilting the cab. Optionally, the tilting device is configured to automatically tilt the cab (e. g. upon an activation of a user).
[0043] Optionally, the motor vehicle is a utility vehicle and in particular a tractor unit. In other words, it can be a motor vehicle that is designed for transporting people, transporting goods or towing trailers.
[0044] According to an embodiment, the cab may be tiltable around a pivot point. When the cab is tilted out of an untilted position the control device may be configured to switch the valve into the second switching state or into the third switching state so as to (for instance substantially) completely contract the at least one air spring, before a centre of gravity of the cab crosses a vertical plumb line through the pivot point cab (e. g. before the centre of gravity crosses a top dead centre). For example, the time for tilting the cab from an untilted position to a position, in which the centre of gravity of the cab crosses the plumb vertical line may be previously known and / or stored on the control device. Further the tilting velocity and / or length of a tilting trajectory may be previously known and / or stored on the control device. Further, an air flow rate of the at least one valve may be dimensioned and / or controlled by the control device such that an at least partial contraction of the at least one valve is achieved before the centre of gravity crosses the plumb line. This is in particular advantageous, because while the mass of the cab may work against the tilting force before the centre of gravity crosses the plumb line, this suddenly may change when the centre of gravity crosses the vertical plumb line (i. e. the mass of the cab may suddenly promote the tilting of the cab). By at least partially contracting the air spring before the crossing of the plumb line, a falling back of the cab may be prevented and / or reduced.
[0045] According to a further general aspect a method for stabilizing a cab of a motor vehicle (for instance as disclosed herein or comprising a system as disclosed herein) is provided. The method comprises the steps:
[0046] Determining a tilted condition of the cab and / or a parked condition of the motor vehicle.
[0047] Blocking an air supply from an air storage to at least one air spring supporting the cab upon the determining of the tilted condition and / or the parked condition.
[0048] Preferably, the method comprises discharging air comprised in the at least one air spring until a contraction limitation device integrated into the at least one air spring limits the contraction of the at least one air spring, wherein optionally the discharging of the at least one air spring is completed before a centre of gravity of the cab crosses a vertical plumb line through a pivot point of the cab.
[0049] Optionally, the method comprises a providing of a motor vehicle comprising a cab and a system as disclosed herein.
[0050] The embodiments, variants and features of the invention described above can be combined with one another as desired. Further details and advantages of the invention are described below with reference to the accompanying drawings.
[0051] Figure 1A a schematic illustration of a cab of a motor vehicle in an untilted position (prior art);
[0052] Figure 1 B a schematic illustration of the cab according to Fig. 1 in a tilted condition (prior art)
[0053] Figure 1C a schematic illustration of a cab of a motor vehicle in an parked condition (prior art);
[0054] Figure 2A a schematic illustration of a cab of a motor vehicle according to one embodiment in an untilted position; Figure 2B a schematic illustration of the cab according to the embodiment of Fig. 2A in a tilted condition;
[0055] Figure 3A a schematic illustration of a cab of a motor vehicle according to one embodiment (before a determination of the parked condition);
[0056] Figure 3B a schematic illustration of the cab according to the embodiment of Fig. 3A in a parked condition;
[0057] Figures 4A-D schematic illustrations of exemplary embodiments of the system;
[0058] Figure 5 a schematic illustration of an air spring according to one embodiment;
[0059] Figure 6 a schematic flow chart of a method according to one embodiment; and
[0060] Figure 7A-C schematic illustrations of a valve according to different embodiments.
[0061] The embodiments shown in the figures are at least partially identical, so that similar or identical parts are provided with the same reference signs and reference is also made to the description of the other embodiments or figures in order to avoid repetitions.
[0062] In some of the figures, exemplary X-, Y- and Z-directions are illustrated. Just exemplarily, the X-direction correlates to the longitudinal direction of the motor vehicle 1000, the Y-direction correlates to the width direction of the motor vehicle 1000 and the Z-direction correlates to the vertical direction of the motor vehicle 1000.
[0063] Figures 1 A-C show motor vehicles 1000 known in the state of the art.
[0064] In the state of the art, it is known to use air springs 1002 as part of the cab suspension system of a cab 1010 of a motor vehicle 1000. Air (e. g. pressurized air) is controllably supplied into the air springs 1002. Typically, a level control means (e. g. integrated into the air spring) is provided, which is configured to control the level of the cab 1010 by controllably discharge air from the respective air spring 1002.
[0065] In particular in utility vehicles, it is further known to tilt the cab e. g. for maintenance reasons. A tilt cylinder 1004 or any other suitable tilt device may be provided that can cause the cab to be tilted around a pivot point 1006 (or pivot axis). Especially air springs 1002 comprising integrated (e. g. internal) level control means are typically arranged above the pivot point 1006 (seen in vertical direction Z). When the cab 1010 is tilted, the cab 1010 at least initially is lifted essentially in the vertical direction Z. This lifting causes that the level control means detects that the cab 1010 is lifted too high and tries to lower the cab by discharging air from the air spring 1002. This results in an undefined condition of the cab suspension and ultimately leads to an undesired rocking and / or uncalm motion while the cab is tilted (see Fig. 1 B).
[0066] Further, when the motor vehicle 1000 is parked, e. g. during rest periods for a driver of the motor vehicle 1000, relative winds 32 and wind gusts (for instance: caused by passing traffic), may lead to a shaking of the cab 1010 which is unpleasant for the persons inside the cab 1010 (see Fig. 1C).
[0067] Figures 2A-B show a cab 110 of a motor vehicle 100 according to an embodiment in an untilted position UP (Fig. 2A) and in a tilted condition TC (Fig. 2B).
[0068] The untilted position UP may be defined by an essentially horizontal orientation and / or a drive position of the cab 110. For the tilting of the cab 110, the motor vehicle 100 may comprise a tilting device 28 (for instance a tilting cylinder).
[0069] Preferably, the cab 110 is a driver’s cab of a motor vehicle 100. However, it is also possible that the motor vehicle 100 is an unmanned motor vehicle 100.
[0070] In particular, the motor vehicle 100 is a semi-autonomous or autonomous motor vehicle 100. The motor vehicle 100 may comprise an electric machine and / or a combustion engine. Preferably, the motor vehicle 100 is a utility vehicle.
[0071] The motor vehicle 100 comprises a system 10 for stabilizing a cab 110 of the motor vehicle 100.
[0072] The system 10 comprises at least one air spring 12a-d, an air storage 18, a fluid connection 20a between the at least one air spring 12a-d and the air storage 18.
[0073] The at least one air spring 12a-d may comprise two front air springs 12a-b arranged opposite each other in width direction Y of the cab 110 (see e. g. Figures 3A, 3B). Optionally, the at least one air spring 12a-d may comprise two rear air springs 12c-d arranged opposite each other in width direction Y of the cab 110 (see e. g. Figures 4 A-D). It is possible that these air springs 12a-d may be supplied with air by individual fluid lines and / or individual branches of a main fluid line. The at least one air spring 12a-d supports the cab 110. In this embodiment. The at least one air spring 12a-d may be arranged (e. g. directly) above a pivot point P of the cab 120. The system 10 further comprises a valve 22a; 22b; 22c; 22d; 22e; 22f; 22g.
[0074] The at least one air spring 12a-d comprises a (e. g. internal) level control means 14. Preferably, the level control means 14 comprises an air discharge valve 14a and / or is integrated into the at least one air spring 12a-d (see e. g. Figure 5).
[0075] The level control means 14 may be configured to discharge air comprised in the at least one air spring 12a-d to an external environment of the at least one air spring 12a-d so as to control a level position of the cab 110 or of the motor vehicle 100.
[0076] The valve 22a; 22b; 22c; 22d; 22e; 22f; 22g is arranged externally of the at least one air spring 12a-d and is integrated into the fluid connection 20a. For instance, the valve 22a; 22b; 22c; 22d; 22e; 22f; 22g may be arranged outside of an inner volume of the at least one air spring 12a-d and / or be structurally independent of the at least one air spring 12a-d.
[0077] The valve 22a; 22b; 22c; 22d; 22e; 22f; 22g is configured to be switched into a first switching state A and into a second switching state B selectively (for instance dependent on a tilted condition TC of the cab 110 and / or a parked condition PC of the motor vehicle 100). Optionally, the valve 22a; 22b; 22c; 22d; 22e; 22f; 22g may be configured to be switched into a third switching state C (for instance dependent on the tilted condition TC of the cab 110 and / or the parked condition PC of the motor vehicle 100).
[0078] In the first switching state A an air supply from the air storage 18 to the at least one air spring 12a-d is enabled (e. g. allowed and / or facilitated).
[0079] In the second switching state B the air supply from the air storage 18 to the at least one air spring 12-d is blocked (e. g. cut and / or closed).
[0080] Thereby, an undesired air supply from the air storage 18 to the at least one air spring 12a-d leading to a rocking motion as described above may be prevented and / or inhibited.
[0081] In the third switching state C the air supply from the air storage 18 to the at least one air spring 12a-d may be blocked and an air discharge from the at least one air spring 12a-d to an external environment of the valve 22a; 22b; 22c; 22d; 22e; 22f; 22g may be enabled.
[0082] The control device 24 may be configured to switch the valve 22a; 22b; 22c; 22d; 22e; 22f; 22g into the second switching state B or into the third switching state C upon determination of the tilted condition TC and / or of the parked condition PC.
[0083] In order to determine the tilted condition TC and / or the parked condition PC, the system 10 may optionally comprise a determination device 25 (see e. g. Fig. 4A-D). The determination device 25 may comprise a sensor element and / or a user input element. The sensor element may be configured to detect the tilted condition TC of the cab 110 and / or the parked condition PC of the motor vehicle 100. It is also possible that the determination device 25 may be configured to determine the tilted condition TC of the cab 110 and / or the parked condition PC of the motor vehicle 100 upon a user input via the user input element (for instance: located inside the cab 110).
[0084] For instance, the determination device 25 may be configured to generate a signal in response to the determination of the tilted condition TC and / or the parked condition and to transmit the signal to the control device 24. Upon the receipt of the signal, the control device 24 may be configured to switch the valve 22a; 22b; 22c; 22d; 22e; 22f; 22g into the second switching state B or the third switching state C.
[0085] The tilted condition TC (see Figure 2B) may be determined (e. g. by the determination device 25) upon a tilting of the cab 110 out of an untilted position UP (see Figure 2A) of the cab 110.
[0086] By switching the valve 22a; 22b; 22c; 22d; 22e; 22f; 22g into the second switching state B or into the third switching state C, the control device 24 may cause an at least partial (for instance substantially complete) contraction of the at least one air spring 12a-d. Thereby, the at least one air spring 12a-d may not contribute to and / or may not provide a counter force to a tilting force.
[0087] For instance, the at least one air spring 12a-d may comprise a contraction limitation device 26a, 26b (e. g. a bump stop 26a and a counter element 26b; see Figure 5) integrated into the at least one air spring 12a-d. In the second switching state B or in the third switching state C the contraction limitation device 26a, 26b may limit the contraction of the at least one air spring 12a-d. By way of example, the bump stop 26a contacts the counter element 26b in the second switching state B or in the third switching state C such that a further contraction is prevented and / or inhibited. The bump stop 26a may comprise a material e. g. of Polyurethane or elastomer or natural rubber.
[0088] Preferably, a centre of gravity CG of the cab 110 travels along a trajectory around a pivot point P during the tilting.
[0089] It is preferred that the control device 24 may be configured to switch the valve 22a; 22b; 22c; 22d; 22e; 22f; 22g into the second switching state B or into the third switching state C so as to at least partially (for instance substantially completely) contract the at least one air spring 12a- d before a centre of gravity CG of the cab 110 crosses a plumb vertical line V through a pivot point P of the cab 110. Figure 2B illustrates the situation just before the centre of gravity CG crosses the vertical plumb line V. Thereby, a “falling-back” of the cab 110, which occurs in conventional systems when the centre of gravity CG crosses the vertical plumb line, may be prevented.
[0090] Figures 3A-B show a cab 110 of a motor vehicle 100 according to an embodiment. In Figure 3A, the parked condition PC is not yet determined by the system 10. Figure 3B shows the situation in which the parked condition PC has been determined.
[0091] In the situation illustrated exemplarily, a driver of the motor vehicle 100 intends to rest and therefore to park the motor vehicle 100. However, the cab 110 is subjected to relative winds 32.
[0092] In the cab 110, there may be provided a user input element, namely a push button, which the driver can activate in order to signal the parked condition PC of the vehicle 110. It is further possible that the parked condition PC of the vehicle 110 is detected automatically.
[0093] As illustrated in Fig. 3A, before the push button is pressed, i. e. before the parked condition PC is determined, the cab 110 experiences a shaking motion caused by the relative winds 32.
[0094] This shaking motion is eliminated by the system 10 as explained above, when the driver activates the push button and therefore the parked condition PC is determined. Upon determination of the parked condition PC, the at least one air spring 12a-d may provide a stable static position of the cab 110.
[0095] Figures 4A-D show exemplary embodiments of the system 10. Each of these Figures comprises partial sectional views S encircled by dashed lines for a better illustration of the inlets and / or outlets of the respective air springs 12a-d.
[0096] In the embodiments shown in Figures 4A-D the at least one air spring 12a-d exemplarily comprises two front air springs 12a, 12b and two rear air springs 12c, 12d. The embodiments further comprise a control device 24 as disclosed herein that is signal connected to a determination device 25 as disclosed herein. In the embodiments shown in Figures 4A-D, the valve 22a; 22b; 22c; 22d; 22e; 22f; 22g is fluidically connected to an air storage 18.
[0097] In the embodiment of Figure 4A, a fluid connection 20a is provided, wherein a branch of the fluid connection 20a fluidically connects the valve 22a to respective inlets I of the two front air springs 12a, 12b. A further branch of the fluid connection 20a fluidically connects the valve 22a to an inlet I of one rear air spring 12c of the two rear air springs 12c, 12d. Further, respective inlets / outlets I / O of the rear air springs 12c, 12d are fluidically connected via an interconnecting fluid connection 20d. The front air springs 12a, 12b and one of the rear air springs 12c, 12d comprise an outlet O to an environment of the respective air spring 12a, 12b, 12c (e. g. via the internal level control means 14).
[0098] In the embodiment of Figure 4A, the valve 22a - just exemplarily - is a 3 / 2-valve. The valve 20a hence can be switched into a first switching state A and a second switching state B. In a normal driving mode, the control device 24 switches the valve 22a in the first switching state A, thereby enabling an air supply from the air storage 18 to the air springs 12a, 12b 12c. When the determination device 25 determines a parked condition PC and / or a tilted condition TC as disclosed herein, a signal is sent to the control device 24. Upon the receipt of this signal, the control device 24 switches the valve 22a into the second switching state B, thereby blocking an air supply from the air storage to the air springs 12a, 12, 12c.
[0099] The achievable modes and respective switching states are summarized in below table:
[0100] Table 1
[0101] The 3 / 2-valve 22a of the embodiment of Figure 4A could -just exemplarily - be exchanged by a 3 / 3-valve 22f shown in Figure 7A. The achievable modes and respective switching states of valve 22f are summarized in below table:
[0102] Table 2 The 3 / 2-valve 22a of the embodiment of Figure 4A could further - just exemplarily - be exchanged by a 3 / 2-valve 22e shown in Figure 7B, wherein the achievable modes and respective switching states of valve 22e are summarized in below table:
[0103] Table 3
[0104] In the embodiment of Figure 4B, a fluid connection 20a and a second fluid connection 20b is provided, wherein a branch of the fluid connection 20a fluidically connects the valve 22b to respective inlets I of the two front air springs 12a, 12b. A further branch of the fluid connection 20a fluidically connects the valve 22b to an inlet I of one rear air spring 12c of the two rear air springs 12c, 12d. Further, respective inlets / outlets I / O of the rear air springs 12c, 12d are fluidically connected via an interconnecting fluid connection 20d. The front air springs 12a, 12b and one rear air spring 12c of the two rear air springs 12c, 12d comprise an outlet O to an environment of the respective air spring 12a, 12b, 12c (e. g. via the respective internal level control means 14). A branch of the second fluid connection 20b fluidically connects respective further outlets O of the front air springs 12a, 12b to the valve 22b. A further branch of the second fluid connection 20b fluidically connects an outlet of the second rear air spring 12d of the two rear air springs 12d to the valve 22b.
[0105] In the embodiment of Figure 4B, the valve 22b - just exemplarily - is a 4 / 2-valve. The valve 22b hence can be switched into a first switching state A and a second switching state B.
[0106] The control device 24 and the determination device 25 essentially operate as described with regard to above Figure 4A.
[0107] In the first switching state A an air discharge from the at least one air spring 12a-d via the second fluid connection 20b to the environment may be blocked and in the second switching state B an (e. g. uncontrolled and / or unregulated) air discharge from the at least one air spring 12a-d via the second fluid connection 20b to the environment may be enabled. The achievable modes and respective switching states of this embodiment are summarized in below table:
[0108] Table 4
[0109] The 4 / 2-valve 22b of the embodiment of Figure 4B could - just exemplarily - be exchanged by a 4 / 3-valve 22g shown in Figure 7C. The achievable modes and respective switching states of valve 22g are summarized in below table:
[0110] Table 5
[0111] In the embodiment of Figure 4C, a fluid connection 20a and a further fluid connection 20c is provided, wherein a branch of the fluid connection 20a fluidically connects the valve 22c to respective inlets I of the two front air springs 12a, 12b. A further branch of the fluid connection 20a fluidically connects the valve 22c to an inlet I of one rear air spring 12c of the two rear air springs 12c, 12d. Further, an inlet / outlet I / O and an inlet I of the rear air springs 12c, 12d are fluidically connected via an interconnecting fluid connection 20d. A branch of the further fluid connection 20c fluidically connects respective further outlets O (e. g. via the respective internal level device 14) of the front air springs 12a, 12b to the valve 22c. A further branch of the further fluid connection 20c fluidically connects an outlet O of the second rear air spring 12d of the two rear air springs 12d to the valve 22c.
[0112] In the embodiment of Figure 4C, the valve 22c - just exemplarily - is a 4 / 3-valve. The valve 22c hence can be switched into a first switching state A, a second switching state B and a third switching state C. The control device 24 and the determination device 25 essentially operate as described with regard to above Figure 4A.
[0113] In the first switching state A and in the third switching state C, an (e. g. controlled and / or regulated) air discharge from the at least one air spring 12a-d via the level control means 14 and via the further fluid connection 20c to the environment may be enabled. In the second switching state B an air discharge from the at least one air spring 12a-d via the level control means 14 and via the further fluid connection 20c to the environment may be blocked.
[0114] The achievable modes and respective switching states are summarized in below table:
[0115] Table 6
[0116] In the embodiment of Figure 4D, a fluid connection 20a, a second fluid connection 20b and a further fluid connection 20C is provided. A branch of the fluid connection 20a fluidically connects the valve 22d to respective inlets I of the two front air springs 12a, 12b. A further branch fluidically connects the valve 22d to an inlet I of one rear air spring 12c of the two rear air springs 12c, 12d. A further fluid connection 20c fluidically connects respective outlets O (e. g. the respective internal level device 14) of the two front air springs 12a, 12b and one rear air spring 12c to the valve 22d. Further, an inlet / outlet I / O and an inlet I of the rear air springs 12c, 12d are fluidically connected via an interconnecting fluid connection 20d.
[0117] A branch of the second fluid connection 20b fluidically connects respective further outlets O of the front air springs 12a, 12b to the valve 22d. A further branch of the second fluid connection 20b fluidically connects an outlet of the second rear air spring 12d one of the two rear air springs 12d to the valve 22d.
[0118] In the embodiment of Figure 4D, the valve 22d - just exemplarily - is a 5 / 3-valve. The valve 22d hence can be switched into a first switching state A, a second switching state B and a third switching state C.
[0119] The control device 24 and the determination device 25 essentially operate as described with regard to above Figure 4A.
[0120] In the first switching state A and in the second switching state B an (e. g. controlled and / or regulated) air discharge from the at least one air spring 12a-d via the second fluid connection 20b to the environment may be blocked. In the third switching state C, an (e. g. uncontrolled and / or unregulated) air discharge from the at least one air spring 12a-d via the second fluid connection 20b to the environment may enabled. In the first switching state A and in the second switching state B an air discharge from the at least one air spring 12a-d via the level control means 14 and via the further fluid connection 20c to the environment may be enabled. In the third switching state C, an air discharge from the at least one air spring 12a-d via the level control means 14 and via the further fluid connection 20c to the environment may be blocked.
[0121] The achievable modes and respective switching states are summarized in below table:
[0122] Table 7
[0123] Figure 5 shows a sectional view of an air spring 12a-d according to one embodiment.
[0124] In this embodiment, pressurized air can be supplied into the air spring 12a-d thereby expanding the air spring 12a-d in vertical direction Z. For discharging air from the air spring 12a-d, the air spring 12a-d may comprise the level control means 14 schematically illustrated.
[0125] The level control means 14 and / or the air discharge valve 14a may be integrated into the at least one air spring 12a-d (e. g. by being arranged in the inner volume of the air spring 12a-d).
[0126] Air comprised in the at least one air spring 12a-d may be dischargeable via the level control means 14 thereby resulting in a contraction in vertical direction Z of the air spring 12a-d.
[0127] For this purpose, the level control means may comprise an air discharge valve 14a fluidically connecting an inner volume of the air spring 12a-d to an external environment of the air spring 12a-d or an air discharge fluid connection.
[0128] In the inner volume of the air spring 12a-d, there may be provided a bump stop 26a and a counter element 26b. For instance in the driving mode as disclosed herein, the bump stop 26a does not contact the counter element 26b. A contraction of the air spring 12a-d in the vertical direction Z caused by an air discharge (e. g. via the level control means 14) may cause the bump stop 26a to move towards the counter element 26b until the bump stop 26a contacts the counter element 26b. A further contraction in the vertical direction Z of the air spring 12a-d thereby may be inhibited and / or prevented. Thus, a stable static position may be achieved. Figure 6 shows an flow chart illustrating the steps of a method for stabilizing a cab 110 of a motor vehicle 100 (for instance as disclosed herein or comprising a system 10 as disclosed herein) according to one embodiment.
[0129] The method comprises the steps:
[0130] Determining a tilted condition TC of the cab 110 and / or a parked condition PC of the motor vehicle 100.
[0131] Blocking an air supply from an air storage 18 to at least one air spring 12a-d supporting the cab 110 upon the determining of the tilted condition TC and / or the parked condition PC.
[0132] Optionally, the method comprises discharging air comprised in the at least one air spring 12a- d until a contraction limitation device 26a, 26b integrated into the at least one air spring 12a-d limits the contraction of the at least one air spring 12a-d, wherein optionally the discharging of the at least one air spring 12a-d is completed before a centre of gravity CG of the cab 110 crosses a vertical plumb line V through a pivot point P of the cab 110.
[0133] Although the invention has been described with reference to specific embodiments, it is be apparent to a person skilled in the art that various modifications may be made and equivalents may be used as substitutes without departing from the scope of the invention. Consequently, the invention is not intended to be limited to the disclosed embodiments, but is intended to encompass all embodiments falling within the scope of the appended claims. In particular, the invention also claims protection for the subject matter and features of the dependent claims independently of the referenced claims. All range specifications herein are to be understood as disclosed such that all values falling within the respective range are disclosed individually, e.g. also as preferred narrower outer limits of the respective range.
[0134] List of reference signs
[0135] 10 System
[0136] 12a-d Air spring
[0137] 14 Level control means
[0138] 14a Discharge valve
[0139] 18 Air storage
[0140] 20a Fluid connection
[0141] 20b Second fluid connection
[0142] 20c Further fluid connection
[0143] 20d Interconnecting fluid connection
[0144] 22a Valve
[0145] 22b Valve
[0146] 22c Valve
[0147] 22d Valve
[0148] 22e Valve
[0149] 22f Valve
[0150] 22g Valve
[0151] 24 Control device
[0152] 25 Determination device
[0153] 26a Bump stop
[0154] 26b Counter element
[0155] 28 Tilting device
[0156] 32 relative winds
[0157] 100 Motor vehicle
[0158] 110 Cab
[0159] 1000 Motor vehicle (prior art)
[0160] 1002 Air spring (prior art)
[0161] 1004 Tilt cylinder (prior art)
[0162] 1006 Pivot point (prior art)
[0163] 1010 Cab (prior art)
[0164] A First switching state
[0165] B Second switching state
[0166] C Third switching state I Inlet
[0167] I / O Inlet / outlet
[0168] O Outlet TO Tilted condition
[0169] PC Parked condition
[0170] UP Untilted position
[0171] P Pivot point CG Centre of gravity
[0172] V Vertical plumb line
[0173] X Longitudinal direction
[0174] Y Width direction Z Vertical direction
Claims
Patent Claims1. A system (10) for stabilizing a cab (110) of a motor vehicle (100), preferably a utility vehicle, comprising: at least one air spring (12a-d), wherein the at least one air spring (12a-d) comprises a level control means (14), preferably wherein the level control means (14) comprises an air discharge valve (14a) and / or is integrated into the at least one air spring (12a-d); an air storage (18); a fluid connection (20a) between the at least one air spring (12a-d) and the air storage (18); and a valve (22a; 22b; 22c; 22d; 22e; 22f; 22g), wherein the valve (22a; 22b; 22c; 22d; 22e; 22f; 22g) is arranged externally of the at least one air spring (12a-d) and is integrated into the fluid connection (20a) and wherein the valve (22a; 22b; 22c; 22d; 22e; 22f; 22g) is configured to be switched into a first switching state (A) and into a second switching state (B), preferably dependent on a tilted condition (TC) of the cab (110) and / or a parked condition (PC) of the motor vehicle (100), wherein: in the first switching state (A) an air supply from the air storage (18) to the at least one air spring (12a-d) is enabled; and in the second switching state (B) the air supply from the air storage (18) to the at least one air spring (12a-d) is blocked; preferably a determination device (25), wherein the determination device (25) is configured to determine the tilted condition (TC) of the cab (110) and / or the parked condition (PC) of the motor vehicle (100).
2. The system (10) according to claim 1 , wherein the valve (22a; 22b; 22c; 22d; 22e; 22f; 22g) is configured to be switched into a third switching state (C), preferably dependent on the tilted condition (TC) of the cab (110) and / or the parked condition (PC) of the motor vehicle (100), wherein in the third switching state (C) the air supply from the air storage (18) to the at least one air spring (12a-d) is blocked and an air discharge from the at least one air spring (12a-d) to an external environment of the valve (22a; 22b; 22c; 22d; 22e; 22f; 22g) is enabled.
3. The system (10) according any one of the preceding claims, comprising a control device (24), wherein the control device (24) is configured to switch the valve (22a; 22b; 22c; 22d;22e; 22f; 22g) into the second switching state (B) or into the third switching state (C) upon determination of the tilted condition (TC) and / or of the parked condition (PC).
4. The system (10) according to claim 3, wherein the control device (24) is configured to switch the valve (22a; 22b; 22c; 22d; 22e; 22f; 22g) into the second switching state (B) or into the third switching state (C) to at least partially discharge air comprised in the at least one air spring (12a-d), preferably so that the at least one air spring (12a-d) does not contribute to and / or does not provide a counter force to a tilting force and / or so that the at least one air spring (12a-d) provides a stable static position of the cab (110).
5. The system (10) according to any one of claims 3 or 4, wherein the control device (24) is configured to switch the valve (22a; 22b; 22c; 22d; 22e; 22f; 22g) into the second switching state (B) or into the third switching state (C) so as to at least partially, preferably completely, contract the at least one air spring (12a-d) before a centre of gravity (CG) of the cab (110) crosses a vertical plumb line (V) through a pivot point (P) of the cab (110).
6. The system (10) according to any one of claims 3 to 5, wherein the at least one air spring (12a-d) comprises a contraction limitation device (26a, 26b), preferably a bump stop (26a) and a counter element (26b), integrated into the at least one air spring (12a-d), wherein in the second switching state (B) or in the third switching state (C) the contraction limitation device (26a, 26b) limits the contraction of the at least one air spring (12a-d), preferably wherein the bump stop (26a) contacts the counter element (26b).
7. The system (10) according to any one of the preceding claims, wherein the level control means (14) is configured to discharge air comprised in the at least one air spring (12a-d) to an external environment of the at least one air spring (12a-d) so as to control a level position of the cab (110) or of the motor vehicle (100).
8. The system (10) according to any one of the preceding claims, wherein the tilted condition (TC) is determined, preferably by the determination device (25), upon a tilting of the cab (110) out of an untilted position (UP) of the cab (110).
9. The system (10) according to any one of the preceding claims, wherein the determination device (25) comprises: a sensor element, wherein the sensor element is configured to detect the tilted condition (TC) of the cab (110) and / or the parked condition (PC) of the motor vehicle (100); and / ora user input element, wherein the determination device (25) is configured to determine the tilted condition (TC) of the cab (110) and / or the parked condition (PC) of the motor vehicle (100) upon a user input via the user input element.
10. The system (10) according to any one of the preceding claims, wherein in the second switching state (B), an air discharge from the at least one air spring (12a-d) to an external environment of the valve (22a; 22f; 22e) is enabled or blocked.
11. The system (10) according to any one of the preceding claims, comprising: a second fluid connection (20b), wherein the second fluid connection (20b) fluidically connects the at least one air spring (12a-d) via the valve (22b; 22g) to an environment of the valve (22b; 22g), wherein in the first switching state (A) an air discharge from the at least one air spring (12a-d) via the second fluid connection (20b) to the environment is blocked and in the second switching state (B) an air discharge from the at least one air spring (12a-d) via the second fluid connection (20b) to the environment is enabled.
12. The system (10) according to any one of claims 1 to 10, comprising: a further fluid connection (20c), wherein the further fluid connection (20c) fluidically connects the level control means (14) via the valve (22c) to an environment of the valve (22c), wherein in the first switching state (A) and in the third switching state (C) an air discharge from the at least one air spring (12a-d) via the level control means (14) and via the further fluid connection (20c) to the environment is enabled and in the second switching state (B) an air discharge from the at least one air spring (12a-d) via the level control means (14) and via the further fluid connection (20c) to the environment is blocked.
13. The system (10) according to any one of claims 1 to 10, comprising: a second fluid connection (20b), wherein the second fluid connection (20b) fluidically connects the at least one air spring (12a-d) via the valve (22d) to an environment of the valve (22d), wherein in the first switching state (A) and in the second switching state (B) an air discharge from the at least one air spring (12a-d) via the second fluid connection (20b) to the environment is blocked and in the third switching state (C) an air discharge from the at least one air spring (12a-d) via the second fluid connection (20b) to the environment is enabled; and a further fluid connection (20c), wherein the further fluid connection (20c) fluidically connects the level control means (14) via the valve (22d) to an environment of the valve (22d), wherein in the first switching state (A) and in the second switching state (B) an air discharge from the at least one air spring (12a-d) via the level control means (14) and viathe further fluid connection (20c) to the environment is enabled and in the third switching state (C) an air discharge from the at least one air spring (12a-d) via the level control means (14) and via the further fluid connection (20c) to the environment is blocked.
14. The system (10) according to any one of the preceding claims, comprising at least one of the following features: the valve (22a; 22b; 22c; 22d; 22e; 22f; 22g) comprises a 3 / 2-valve (22a; 22e), 3 / 3- valve (22f), 4 / 2- valve (22b), 4 / 3- valve (22c, 22g) or a 5 / 3-valve (22d); the air discharge valve (14a) is integrated into the at least one air spring (12a-d); the at least one air spring (12a-d) is arranged, preferably directly, above a pivot point (P) of the cab (120); the at least one air spring (12a-d) comprises two front air springs (12a-b) arranged opposite each other in width direction (Y) of the cab (110) and preferably two rear air springs (12c-d) arranged opposite each other in width direction (Y) of the cab (110).
15. A motor vehicle (100), preferably a utility vehicle, wherein the motor vehicle (100) comprises: a system (10) according to any one of the preceding claims; a cab (110), wherein the at least one air spring (12a-d) supports the cab (110); and preferably a tilting device (28), optionally a tilting cylinder, for tilting the cab (110).
16. The motor vehicle (100) according to claim 15, wherein the cab (110) is tiltable around a pivot point (P), wherein when the cab (110) is tilted out of an untilted position (UP), the control device (24) is configured to switch the valve (22a; 22b; 22c; 22d; 22e; 22f; 22g) into the second switching state (B) or into the third switching state (C) so as to, preferably substantially, completely contract the at least one air spring (12a-d), before a centre of gravity (CG) of the cab (110) crosses a vertical plumb line (V) through the pivot point (P) cab (110).
17. A method for stabilizing a cab (110) of a motor vehicle (100), preferably according to any one of claims 15 or 16 or comprising a system according to any one of claims 1 to 14, wherein the method comprises the steps: determining a tilted condition (TC) of the cab (110) and / or a parked condition (PC) of the motor vehicle (100);blocking an air supply from an air storage (18) to at least one air spring (12a-d) supporting the cab (110) upon the determining of the tilted condition (TC) and / or the parked condition (PC); and preferably discharging air comprised in the at least one air spring (12a-d) until a contraction limitation device (26a, 26b) integrated into the at least one air spring (12a-d) limits the contraction of the at least one air spring (12a-d), wherein optionally the discharging of the at least one air spring (12a-d) is completed before a centre of gravity (CG) of the cab (110) crosses a vertical plumb line (V) through a pivot point (P) of the cab (110). ****)
Citation Information
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