motor vehicle

Abstract

The invention relates to a motor vehicle (1) with air springs (3a, 3b) each associated with a vehicle wheel (2a, 2b). What is essential to the invention is that between two air springs (3a, 3b) of an axle, a connecting channel (6) formed by a strut brace (4) or a subframe (5) is provided for the pneumatic connection of the two air springs (3a, 3b).

Description

[0001] The present invention relates to a motor vehicle with air springs each assigned to a vehicle wheel, according to the preamble of claim 1.

[0002] DE 39 09 916 A1 discloses a motor vehicle with two wheels arranged on an axle, each of which is assigned an air spring. A connecting channel for pneumatically connecting the two air springs runs between the two air springs on the axle.

[0003] From DE 11 64 251 A1 an air suspension for motor vehicles with a self-supporting body is known, the axles of which are supported against the vehicle superstructure by means of a cross member serving as an axle assembly carrier by means of self-contained elastic air suspension bellows provided between the cross member and each axle half.

[0004] DE 10 2015 106 425 A1 discloses an arrangement of a compressed air reservoir for an air suspension system in a motor vehicle, which is held in a cavity of a vehicle body. The compressed air reservoir is embedded in a cavity of a vehicle sill, surrounded by the walls of the sill, and is held in a wedged position by a locking device comprising rubber-elastic retaining elements, soundproofing it and clamping it.

[0005] From DE 10 2016 200 959 A1 a trim element for a motor vehicle is known which comprises an integrated compressed gas reservoir for an air suspension system of the motor vehicle.

[0006] DE 195 08 854 A1 discloses a motor vehicle with air springs assigned to each vehicle wheel. The individual air springs are connected to a reservoir acting as a compressed air tank. At least one compressed air tank is arranged within a cavity formed by at least one vehicle part independent of the actual air suspension.

[0007] From DE 10 2008 054 114 A1, a vehicle chassis element in hollow chamber construction is known, so that the vehicle chassis element, in addition to its primary function as a chassis component, is designed at least in a partial volume as a storage volume in which a gaseous or liquid medium can be stored.

[0008] DE 10 2011 106 250 A1 discloses a subframe for a vehicle chassis of a motor vehicle. The subframe has at least one cavity usable as a pressure accumulator and a cross member connected to a node element at each of its two end faces. Bearing elements and / or additional frame elements are attached to the node elements. The cross member itself is designed as a continuous, rib-reinforced structural or extruded profile and forms a pressure-resistant cavity for the pressure accumulator, which is closed off at the end face by the node elements.

[0009] From CN 217402265 U, a gas storage device and a motor vehicle are known, wherein the gas storage device has a first cross member, a second cross member and a first longitudinal member, and wherein the first cross member is provided with a first gas storage chamber. The second cross member and the first cross member are arranged at a distance from one another, wherein a second gas storage chamber is arranged in the second cross member. The first longitudinal member is connected to the first cross member and the second cross member, whereby the two cross members with their respective gas storage chambers can increase a total gas storage capacity and thereby increase a lifting frequency of the motor vehicle and, if necessary, can cause the motor vehicle to be lifted several times.

[0010] DE 10 2019 119 567 A1 discloses a method for producing and leak-testing a gas-tight and pressure-resistant container in a crossbeam of a support profile of a chassis subframe of a motor vehicle, designed as a hollow space. The crossbeam is connected at each of its two end faces to a node element as a connecting element, and these end faces close the crossbeam in the transverse direction by means of two inserted bulkheads, which form the side walls of the pressure-resistant container. In the method, a gas-tight bulkhead is first welded into each end region of the support profile of the crossbeam to form the container. Subsequently, the container is pressurized and filled with a helium gas mixture, sealed, and then transported to a test chamber.In the test room, any escaping helium atoms are now detected to determine whether a fault has occurred. If the result is negative, the node elements are subsequently joined and connected to at least one crossbeam in a welding device.

[0011] DE 10 2004 030 469 A1 discloses a motor vehicle with a pressure chamber containing a switchable or permanently connected additional volume of an air spring in a cavity of a motor vehicle body. The cavity of the motor vehicle body is sealed from the environment and connected to the air spring via a line. This allows the air spring to require very little installation space in the vehicle.

[0012] DE 10 2015 000 650 A1 discloses a front-end structure of a vehicle body comprising a cross-member encompassing a firewall, strut towers arranged on both sides of the front-end structure with adjoining wheel houses, a V-shaped strut brace connecting the strut towers to the cross-member, and an air conditioning unit arranged in the firewall. The strut brace is designed as an air duct for the air conditioning unit, with air inlets located at the ends of the strut brace near the dome and an air outlet located at the V-shaped tip of the strut brace.

[0013] DE 10 2007 019 062 A1 discloses a strut brace for connecting the spring strut towers of a motor vehicle, with a cross member connecting the strut towers. This cross member has at least one fluid reservoir.

[0014] In motor vehicles, ride comfort is also influenced by pitching and rolling movements, so reducing roll movements, for example, would significantly improve ride comfort. Especially in modern, air-sprung vehicles, where air springs assigned to each wheel can be individually controlled, reducing roll motion requires a significant and therefore costly control effort.

[0015] The present invention therefore addresses the problem of providing an improved or at least an alternative embodiment for a motor vehicle of the generic type, by means of which, in particular, the driving comfort of the motor vehicle can be increased in a structurally simple manner and thus cost-effectively.

[0016] This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0017] The present invention is based on the general idea of ​​pneumatically coupling two air springs of two vehicle wheels on a common axle in an air-sprung motor vehicle via a connecting channel integrated into a body component or in a chassis component, whereby in the event of one-sided road excitation a comparatively simple pressure equalization to the opposite air spring takes place and thereby a spring force and a one-sided lifting force can be reduced or a compensating force for the rolling movement takes place through the pressure equalization, whereby due to the integration of the connecting channel into the body component or the chassis component no further separate components have to be provided and installed.In the motor vehicle according to the invention, each vehicle wheel is assigned a respective air spring, wherein, according to the invention, a connecting channel formed by a strut brace or a subframe is provided between two air springs of a common axle for the pneumatic connection of the two air springs.

[0018] If the two vehicle wheels are mounted on a front axle, the connecting channel connecting the two air springs on the front axle is formed by the strut brace, whereas on a rear axle, the connecting channel connecting the two air springs is formed by a subframe. This not only allows the previously described improvements in ride comfort to be achieved, but also allows them to be implemented with comparatively little design effort and thus cost-effectively, since separate connecting lines, which would have to be manufactured, stored, and installed separately, are eliminated.By integrating the connecting channel into the chassis subframe or strut brace, an additional function can be assigned to a component already present in the vehicle, namely that of pneumatic air compensation between two air springs of two vehicle wheels on a common axle, whereby the functionality of the strut brace or chassis subframe can be increased.

[0019] In an advantageous development of the motor vehicle according to the invention, the strut brace is designed as an internal high-pressure formed part. In internal high-pressure forming, commonly also called hydroforming, metallic hollow bodies are formed in a closed mold using internal pressure. The pressure is usually introduced into the hollow body by a water-oil emulsion. The major advantage of internal high-pressure forming is the great design freedom for complex component shapes, the minimization of assembly and / or welded joints, and at the same time, savings in material and weight. In addition, such internal high-pressure formed components have greater mechanical strength than, for example, welded components. Additionally or alternatively, the chassis subframe can also be designed as an internal high-pressure formed part.

[0020] According to the invention, a switchable valve is arranged in the area of ​​the connecting channel. Such a switchable valve can also influence a roll movement, so that, for example, with appropriately selected driving programs, individual switching of the valve and thus individual pressure equalization between the two air springs on a common axle can be individually selected. The switchable valve is used, in particular, to control the air flow through the connecting channel.

[0021] In a particularly preferred embodiment of the motor vehicle according to the invention, a clear cross-section of the connecting channel is approximately 315 mm 2 . Such a clear cross-section of approximately 315 mm 2This would equate to an inner diameter of approximately 20 mm for a circular connecting channel. This magnitude demonstrates how small a connecting channel's cross-section can be, allowing it to be easily accessed using a cross-section typically found in a subframe or strut brace.

[0022] A reservoir for compressed air is conveniently provided in the connecting duct. If the clear cross-sectional area of ​​the connecting duct exceeds the 315 mm mentioned in the previous paragraph, 2, the remaining cross-sectional area and the resulting volume can be used as a reservoir for compressed air. This would allow part of the required air spring volume to be relocated from the respective air springs to the strut brace or subframe, making the air springs themselves smaller, lighter, and more cost-effective. With the air springs remaining the same size, the additional compressed air volume can then be used to increase comfort.

[0023] Alternatively, it is of course also conceivable for the connecting duct to be connected to a compressed air reservoir located outside the strut brace or subframe. In this case, the compressed air reservoir is not located inside the subframe or strut brace, but outside it and is connected to the connecting duct for fluid transmission. However, if the air volume present in the subframe or strut brace is large enough, locating the compressed air reservoir in the connecting duct—specifically, in the subframe or strut brace—is a suitable option.

[0024] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0025] It is understood that the features mentioned above and those to be explained below can be used not only in the respective combination specified, but also in other combinations or on their own, without departing from the scope of the invention as defined by the claims. Components mentioned above and those to be mentioned below of a higher-level unit, such as a device, a device, or an arrangement, which are designated separately, may form separate parts or components of this unit or be integral areas or sections of this unit, even if this is shown differently in the drawing.

[0026] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0027] The diagrams show schematically Fig. 1 a sectional view through a motor vehicle according to the invention in the area of ​​a front axle with a connecting channel running in a strut brace between two air springs, Fig. 2 a representation as in Fig. 1, but on a rear axle of the motor vehicle with a connecting channel running in a subframe for the pneumatic connection of two air springs.

[0028] According to the Fig. 1 and Fig. 2, a motor vehicle 1 according to the invention has an associated air spring 3a, 3b on each vehicle wheel 2a, 2b. The vehicle wheels 2a, 2b or the two associated air springs 3a, 3b are thus connected to a common axle, ie either to a front axle (see Fig. 1) or on a rear axle (compare Fig. 2) arranged.

[0029] According to the invention, between two air springs 3a, 3b of the same axle, a strut bar 4 (compare Fig. 1) or a subframe 5 ( Fig. 2) formed connecting channel 6 for the pneumatic connection of the two air springs 3a, 3b. In the Fig. 1 and Fig. 2, the respective connecting channel 6 is drawn as if it had its own wall within the strut brace 4 or the subframe 5, whereby it is of course clear that this is to be understood purely schematically, so that the connecting channel 6 is delimited according to the invention by the wall of the strut brace 4 or by the wall of the subframe 5.

[0030] With the motor vehicle 1 according to the invention, several advantages can be realized: On the one hand, a separate connecting line for the pneumatic coupling of the two air springs 3a, 3b arranged on one axle, which would not only have to be manufactured separately but also stored and subsequently assembled, can be omitted, thus achieving considerable cost and space savings. On the other hand, by integrating the connecting line 6 into the strut brace 4 or the subframe 5, a previously unused installation space within the strut brace 4 or within the subframe 5 can now be used for the connecting channel 6, which results in significant installation space advantages.

[0031] The strut brace 4 can, for example, be designed as an internal high-pressure formed part, which results in further advantages, for example, with regard to complex shaping. In the same way, the subframe 5 can of course also be manufactured as an internal high-pressure formed part, whereby internal high-pressure formed parts always offer the advantage of providing a cost-effective, sealed cavity enclosure, which, in particular, eliminates or at least minimizes the risk of leakage, which exists, for example, in weld seams.

[0032] A clear cross-section of the connecting channel 6, ie a cross-section of the connecting channel 6 permeable to compressed air between the two air springs 3a, 3b, can be approx. 315 mm 2, so that in this case, with a circular cross-section of the connecting channel 6, it would have a diameter of approximately 20 mm. If the strut brace 4 or the subframe 5 has a significantly larger clear cross-section for the connecting channel 6, an additional reservoir 7 for compressed air can be provided within the subframe 5 or the compression strut 4. Providing such a reservoir 7 for compressed air within the strut brace 4 or within the subframe 5 also offers the great advantage of being able to reduce the size of the air springs 3a, 3b by the reservoir 7 present in the strut brace 4 or in the subframe 5, and thus not only make them smaller, but also lighter and more cost-effective.

[0033] Additionally or alternatively, it is of course also conceivable that the connecting channel 6 is connected to a reservoir 7a arranged outside the strut brace 4 or outside the subframe 5 (compare Fig. 2) for compressed air, whereby a further increase in comfort can be achieved due to the higher volume of compressed air available.

[0034] In the area of ​​the connecting channel 6, a switchable valve 8 is also arranged, which is controlled according to the Fig. 1 and Fig. 2 is shown separately, but is of course connected to the connecting channel 6 and can cause a throttling of a compressed air flow in the connecting channel 6.

[0035] With the connecting channel 6 arranged according to the invention in the strut brace 4 or in the subframe 5, via which the two air springs 3a, 3b of a common axle are communicatively connected to one another, pressure equalization with the opposite air spring 3b, 3a can occur, particularly in the event of one-sided road excitation, thereby reducing the spring force and one-sided lifting force. The resulting pressure equalization can also reduce roll motion, thereby increasing ride comfort. The integration of the connecting channel 6 into the strut brace 4 or subframe 5 also allows for space and cost advantages.

Claims

[1] Motor vehicle (1) with two vehicle wheels (2a, 2b) arranged on an axle, each of which is assigned an air spring (3a, 3b), wherein a connecting channel (6) for pneumatically connecting the two air springs (3a, 3b) is provided between the two air springs (3a, 3b) of the axle, characterized by , - that the connecting channel is formed by a strut brace (4) or a subframe (5), - that a switchable valve (8) is arranged in the region of the connecting channel (6). [2] Motor vehicle (1) according to claim 1, first alternative, characterized by that the strut brace (4) is designed as an internal high-pressure formed part. [3] Motor vehicle (1) according to claim 1, second alternative, characterized by that the subframe (5) is designed as an internal high-pressure formed part. [4] Motor vehicle (1) according to one of the preceding claims, characterized by that a clear cross-section of the connecting channel (6) is approx. 315 mm 2amounts. [5] Motor vehicle (1) according to one of the preceding claims, characterized by that a reservoir (7) for compressed air is provided in the connecting channel (6). [6] Motor vehicle (1) according to one of claims 1 to 4, characterized by that the connecting channel (6) is connected to a reservoir (7a) for compressed air located outside the strut brace (4) or the subframe (5).

Images