Patent Application
20230043426
The invention relates to a connecting part for a plug-in connection system of a coupling device for automatically coupling a trailer vehicle to a towing vehicle, comprising a contact carrier, a contact structure which is attached to the contact carrier and is engageable with a contact structure of a complementary connecting part of the plug-in connection system in order to establish a plug-in connection with the complementary connecting part during automatic coupling, a closure flap which is pivotable relative to the contact carrier, is biased onto the contact carrier and is releasable from the contact carrier in a pivoting movement against this bias when the plug-in connection is established, and a seal which is arranged on the contact carrier and is elastically deformable by a counterpart pressing on the seal for sealing the contact structure with respect to the exterior space, the counterpart being formed by the closure flap pressing on the seal when the plug-in connection is disconnected and by the complementary connecting part of the plug-in connection system pressing on the seal when the plug-in connection is established. The invention further relates to a plug-in connection system for a coupling device for automatically coupling a trailer vehicle to a towing vehicle.
In the commercial vehicle sector, coupling devices are known that serve to automatically couple a trailer vehicle to a towing vehicle. A semitrailer, for example, usually has a pin arranged on its underside that can be positively locked in a fifth wheel coupling of a tractor. In addition to this mechanical coupling, a plug-in connection system is also provided to supply the trailer vehicle with electrical power and/or compressed air. It is also possible to transmit electrical and/or optical control signals between the tractor and the semitrailer via such a plug-in connection system. Plug-in connection systems of this type are known, for example, from documents DE 10 2008 014 285 A1 and DE 10 2008 014 572 B4.
Accordingly, such a plug-in connection system is formed by two associated connecting parts, one of which is mounted on the towing vehicle and the other on the trailer vehicle. Each of these connecting parts has a contact carrier as well as a plurality of contact elements mounted thereon, which come into engagement in pairs with the contact elements of the respective other connecting part assigned to them when the trailer vehicle is coupled to the towing vehicle. As a rule, the contact elements provided on one connecting part are designed as plugs, while the contact elements of the other connecting part form complementary sockets. As the plugs engage with their associated sockets, the plug-in connections required for the supply of electrical power, electrical and/or optical control signals and compressed air are established between the two connecting parts.
To protect the contact structure formed by the contact elements from environmental influences such as water, dust, etc., the connecting part has a closure flap which is pivotably mounted on the contact carrier and is biased in the direction of the contact carrier, for example by means of a spring. In the uncoupled state, the closure flap presses on a seal attached to the contact carrier. This seal is made of an elastic material so that it deforms when the spring-loaded closure flap presses on the seal. In the coupled state, in which the plug-in connection is established between the two connecting parts forming the plug-in connection system, a suitable mechanism ensures in the interaction of the two connecting parts that the closure flap is pivoted away from the seal against the biasing force. In this state, the other connecting part of the plug-in connection system presses on the seal, thus sealing the contact elements brought into engagement with each other in a fluid-tight manner against the exterior space.
In the prior art, the seal is formed from a sealing plate, which merges in one piece into individual sealing lips, each of which encloses one of the contact elements in an annular shape. A further circumferential sealing lip is formed at the edge of the sealing plate and encloses the contact structure formed by the contact elements as a whole. The individual sealing lips each have a sealing profile in the form of a simple elevation extending in a direction perpendicular to the plane of the plate. Thus, the sealing lip is pressurized by the respective sealing counterpart, i.e. in the uncoupled state by the closure flap and in the coupled state by the complementary connecting part, in a direction that coincides with the direction in which the sealing lip projects from the plate plane.
With regard to the sealing capacity of such a seal, it must be taken into account that a certain compression set occurs with common sealing materials, which is a measure of how much time the sealing material requires to return to its original geometry after deformation under pressure. In the present context, it should also be taken into account that the plug-in connection system exerts significantly different pressing forces on the seal in the coupled and uncoupled states. In the uncoupled state, for example, the closure flap biased onto the seal exerts a significantly lower pressing force on the seal than the complementary connecting part of the plug-in connection system does, for example via pneumatic actuations, in the coupled state. Accordingly, after a certain time in the coupled state, the seal also needs significantly longer to return to its initial geometry than is the case from the uncoupled state. This can mean that the pressing force subsequently exerted on the seal by the biased closure flap in the coupled state is not sufficient to ensure adequate sealing of the contact structure against the exterior space. This means that water or dust can enter the area of the contact structure and contaminate or even damage it.
To achieve the desired tightness, it could be considered to increase the biasing force with which the closure flap is pressed onto the seal in the uncoupled state. However, this would mean that the force opposing the bias, which has to be provided when establishing the plug-in connection to open the closure flap, would be correspondingly large. The mechanisms currently used to open the closure flap might then no longer be suitable and would have to be retrofitted or replaced, which should be avoided in view of the costs involved.
It is the object of the present invention to specify a connecting part provided for a plug-in connection system of a coupling device, which enables an improved sealing effect with little technical effort. Furthermore, it is the object of the invention to provide a plug-in connection system with such a connecting part.
The afore-mentioned objects are solved by the connecting part according to claim 1 and the plug-in connection system according to claim 15. Advantageous embodiments result from the dependent claims and the following description.
The connecting part according to the invention comprises a contact carrier, a contact structure which is attached to the contact carrier and is engageable with a contact structure of a complementary connecting part of the plug-in connection system in order to establish a plug-in connection with the complementary connecting part during automatic coupling, a closure flap which is pivotable relative to the contact carrier, is biased onto the contract carrier and is releasable from the contact carrier in a pivoting movement against this bias when the plug-in connection is established, and a seal which is arranged on the contact carrier and, in order to seal the contact structure with respect to the exterior space, is elastically deformable by a counterpart pressing on the seal, the counterpart being formed by the closure flap pressing on the seal when the plug-in connection is disconnected and by the complementary connecting part of the plug-in connection system pressing on the seal when the plug-in connection is established. The contact carrier has at least one sealing groove enclosing the contact structure. The seal is formed from at least one sealing lip, which is inserted into the sealing groove and thus encloses the contact structure. The sealing lip has a sealing profile which is inclined towards a side facing away from the contact structure, so that the sealing lip deforms elastically toward this side when the counterpart presses on the sealing lip.
In contrast to conventional seals, whose sealing lips form elevations projecting perpendicularly from the contact carrier, the sealing lip according to the invention has a sealing profile which is asymmetrical and undercut, so to speak, in such a way that the profile section projecting from the contact carrier is inclined outwards, i.e. away from the contact structure enclosed by the sealing lip, relative to the surface normal of the contact carrier. This means that in the present invention, in contrast to the prior art, the direction in which the sealing lip rises starting from the contact carrier does not coincide with the direction of the compressive load exerted on the sealing lip by the sealing counterpart, i.e. in the uncoupled state by the spring-biased closure flap. This means that the sealing profile of the sealing lip, which in this case means the cross-section through the sealing lip, springs away outwards as a result of the pressure load, which provides various advantages over conventional sealing geometries.
This means that the sealing material is subjected to less stress as a result of the sealing lip sliding away than in a case where the direction of extension of the sealing profile coincides with the direction of pressurization. On the one hand, this results in a longer service life of the seal. On the other hand, there is a reduction in the compression set, so that the sealing lip returns to its original shape quicker after being subjected to a high compressive load in the coupled state. This ensures, particularly in the period immediately after the plug-in connection is disconnected, that the closure flap, which acts on the seal with a significantly lower pressing force, also provides a reliable seal of the contact elements against the exterior space. Furthermore, the sealing profile according to the invention is selected in such a way that when the plug-in connection is disconnected, splash water directed at the connecting part acts from outside on the sealing lip, which is elastically deformed toward the outside, as a result of which the sealing lip is pressed even stronger against the closure flap by the water. This also increases the sealing effect of the connecting part according to the invention in the uncoupled state.
The seal according to the invention preferably consists exclusively of the at least one sealing lip, which is fastened in the associated sealing groove formed in the contact carrier, for example by injection molding. In other words, with the exception of one or more sealing lips, the seal does not have any other sealing structures, such as a sealing plate used in the prior art. This ensures that the pressure area is defined essentially by the length of the sealing lip alone (or by the summed length when several sealing lips are used). For a given pressing force with which the closure flap acts on the seal, this results in an increased surface or line pressure on the sealing edge, which further increases the sealing effect. In particular, a comparatively moderate bias of the closure flap can be used to achieve the desired sealing effect. When coupling the trailer vehicle to the towing vehicle, this makes it easier to open the closure flap against the biasing force with which the closure flap presses onto the seal.
Preferably, the sealing lip has a profiled section projecting from the contact carrier, which tapers with increasing distance from the contact carrier. This allows the sealing edge formed by the free end of the profile section to be kept narrow to increase the surface pressure. In addition, the taper makes the sealing lip more movable. At the same time, the taper causes the sealing lip to be reinforced in accordance with the bending moment curve. This means that the sealing lip is comparatively thin at its tip, i.e. in the area of its sealing edge where a lower bending moment acts, and thicker toward the contact carrier where a higher bending moment acts.
In a preferred embodiment, the sealing lip has a profile section projecting from the contact carrier, which has a first profile side facing the contact structure and a second profile side facing away from the contact structure, which each have an inclination directed away from the contact structure, the inclination of the first profile side being greater than the inclination of the second profile side. In this way, it is ensured that the sealing edge formed by the free end of the profile section has a greater distance from the contact structure in the projection onto the contact carrier than a base point of the second profile side, which is defined by the end of the second profile side opposite the sealing edge on the plate plane. A pressing force acting on the sealing edge thus reliably ensures that the sealing profile springs outwards away from the contact structure.
For example, the profile section projecting from the contact carrier has essentially the shape of an oblique triangle. However, it goes without saying that a sealing geometry deviating from this can also be selected, provided that such a geometry achieves elastic deformation in the desired direction, i.e. in a direction pointing away from the contact structure.
Preferably, the sealing groove defines a first groove space given by a recess formed in the contact carrier, and a second groove space which adjoins the first groove space and is widened relative to the first groove space. In this embodiment, the sealing lip may have a sealing seat that is fixed in the first groove space, while the profile section of the sealing lip that adjoins the sealing seat is elastically deformable in the widened second groove space. The second groove space defined by the sealing groove provides the sealing lip with sufficient space to avoid the compressive load so to speak by moving sideways, without damaging the sealing lip.
The above-mentioned two-stage design of the sealing groove is to be understood merely as an example. In particular, a single-stage design of the sealing groove is also possible, i.e. a design in which two differently sized groove spaces of the type explained above are dispensed with.
In a special embodiment, several contact elements forming the contact structure can be enclosed by a single sealing lip. Alternatively, it is also possible to use several sealing lips, each of which then encloses a part of the contact elements.
The contact elements are designed as plug-in connection elements, which can be engaged in pairs with their respective associated plug-in connection elements of the contact structure of the complementary connecting part in order to establish the plug-in connection. The respective plug-in connection element can be designed as a plug or socket. In this connection, all plug-in connection elements are preferably provided either in the form of a plug or a socket on the connecting part considered here. Accordingly, the contact elements of the other connecting part are designed in the respective complementary form in order to provide the desired plug-in connections.
The sealing lip is preferably made of an elastic plastic, e.g. an elastomer or a silicone. Based on such a material, the sealing lip can be manufactured, e.g. by injection molding, in the desired design, in particular with the desired elasticity.
Preferably, the connecting part comprises a biasing device which is designed to press the closure flap onto the sealing lip when the plug-in connection is disconnected and to pivot the closure flap away from the sealing lip in cooperation with the complementary connecting part when the plug-in connection is established. Such a biasing device has, for example, one or more spring elements by means of which the closure flap is biased onto the contact carrier so that, in the disconnected state, the closure flap presses with the desired pressing force on the seal fitted in the contact carrier.
Another aspect of the invention provides a plug-in connection system for a coupling device for automatically coupling a trailer vehicle to a towing vehicle. The plug-in connection system comprises a first connecting part of the type described above, and a complementary second connecting part having a contact structure engageable with the contact structure of the first connecting part to establish a plug-in connection with the first connecting part during automatic coupling.
The invention is explained in more detail below with reference to the figures.
In
The two connecting parts 100, 104 forming the plug-in connection system 102 are used to transmit electrical power, compressed air and electrical and/or optical control signals between the towing vehicle and the trailer vehicle. For this purpose, the two connecting parts 100, 104 each have a plurality of contact elements which are brought into engagement with one another in pairs when the trailer vehicle is coupled to the towing vehicle. The contact elements, which are assigned to each other in pairs, are each designed in the form of a plug and a socket in order to establish the desired plug-in connection during the coupling process.
At this point it should be noted that in
For the embodiment shown in
Referring now to
In the embodiment shown, the contact structure 116 comprises two contact units 118 arranged in mirror symmetry with respect to a vertical central axis, which are used, for example, to transmit electrical signals between the two connecting parts 100, 104. These two functional units 118 are formed by the contact elements 106. Furthermore, the contact structure 116 comprises two functional units 120, also arranged mirror-symmetrically on the contact carrier 114, for transmitting compressed air. These pneumatic functional units 120 are formed by the contact elements 108.
The contact carrier 114 further has a centering opening 122 in its central region, into which a matching centering rod (not shown), which is attached to the other connecting part 104, is inserted during the coupling process. The centering opening 122 and the associated centering rod have the function of aligning the two connecting parts 100, 104 in the correct position relative to one another, so that the contact elements 106, 108 of the connecting part 100 engage with the contact elements of the complementary connecting part 104 assigned to them in a precisely fitting manner. The same function is served by two recesses 124 formed on opposite sides of the housing, which cooperate during the coupling process with two matching guide rods (not shown) provided on the complementary connecting part 104.
The connecting part 100 further comprises a closure flap 128 which serves to protect the contact carrier 114 and in particular the contact elements 106, 108 attached thereto from environmental influences such as dust and splash water. For this purpose, the closure flap 128 is mounted on the housing 112 in such a way that it can be pivoted from an open position as shown in
As shown in
The seal composed of the sealing lips 132, 134 serves to seal the contact elements 106, 108 in a fluid-tight and a dust-tight manner from the exterior space both in the uncoupled and in the coupled state, for example to protect the contact elements 106, 108 from dust and splash water. For this purpose, the seal 130 cooperates with a counterpart formed by the closure flap 128 in the uncoupled state and by the complementary connecting part 104 in the coupled state. In both states, in fact, the respective counterpart presses on the seal 130 and thus provides the desired seal.
As mentioned further above, the pressing force which the closure flap 128 exerts on the seal 130 in the uncoupled state is significantly less than the pressing force with which the complementary connecting part 104 presses on the seal 130 in the coupled state. For this reason, as will be explained further on, the present invention aims in particular at configuring the seal 130 composed of the sealing lips 132, 134 in an advantageous manner in such a way that the seal 130 achieves a reliable sealing of the contact structure 116 not only in cooperation with the complementary connecting part 104, but also in cooperation with the closure flap 128 exerting only a comparatively low pressing force.
In
As shown in
This sealing profile, directed away from the contact structure, is best seen in
As shown in
The sectional view according to
The sealing geometry according to the invention is selected so that the direction in which the sealing profile extends away from the contact carrier 114 does not coincide with the direction of pressurization, but is inclined outwardly relative to this direction. This counteracts material fatigue that would otherwise occur over a large number of coupling operations. In addition, this advantageously leads to a reduction in the compression set after the plug-in connection is disconnected, so that subsequently the pressing force exerted by the closure flap 128 on the seal 130 is sufficient to achieve the desired seal.
The detailed view according to
With reference to the detailed view according to
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 100 682.9 | Jan 2020 | DE | national |
This application is a National Phase of International Application No. PCT/EP2021/050619, filed Jan. 14, 2021, which claims the benefit of German Application 10 2020 100 682.9, filed Jan. 14, 2020, both of which are incorporated herein in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/050619 | 1/14/2021 | WO |
