WO2020157611A1

WO2020157611A1 - Bowden cable arrangement for motor vehicle applications

Info

Publication number: WO2020157611A1
Application number: PCT/IB2020/050523
Authority: WO
Inventors: Michael ENDICOTT; David Keehn
Original assignee: Kiekert Ag
Priority date: 2019-01-31
Filing date: 2020-01-23
Publication date: 2020-08-06

Abstract

The invention relates to a Bowden cable arrangement for motor vehicle applications, in particular for manually acting on a motor vehicle latch (1). The arrangement is equipped with at least one Bowden cable (5, 6) having a sheath (5) and a core (6) movable relative to the sheath (5). In addition, a sealing sleeve (10) is implemented on at least one end of the sheath (5). The sealing sleeve (10) has a guide region (12) for the core (6). According to the invention, in cross section, the guide region (12) of the sealing sleeve (10) has at least one point-contact site (14) with the core (6).

Description

Bowden cable arrangement for motor vehicle applications

The invention relates to a Bowden cable arrangement for motor vehicle applications, in particular for manually acting on a motor vehicle latch, preferably for mechanically opening a locking mechanism of the motor vehicle latch in an emergency, comprising at least one Bowden cable that has a sheath and a flexible core capable of moving back and forth relative to and within the sheath, and comprising a sealing sleeve that is arranged on at least one end of the sheath and comprises a guide region for the core.

Bowden cable or control cable arrangements have many applications in relation to motor vehicles. In a typical example, in accordance with the generic prior art according to DE 198 10 665 C1 , tensile forces are transmitted to a door latch by means of an inside door handle. For this purpose, the end of the sheath is supported at one end against a housing of the motor vehicle latch and at the other end against a support part of an associated internal door operation mechanism. In this way, by means of the flexible core, the desired tensile forces can be transmitted from the inside door handle to the motor vehicle latch, and in particular to the motor vehicle door latch, so as to be able to open said latch from inside in the event of internal door operation.

In addition to these, so to speak,“conventional” areas of application for Bowden cable arrangements, other applications in the motor vehicle field are known, for example in connection with window winders, in which the force of a drive motor is transmitted by means of a Bowden cable arrangement of this kind to the window to be moved. In addition, Bowden cable arrangements of this kind are used, for example, to open a fuel cap or even a tailgate from inside. Further areas of application provide for manual opening of a front hood and the operation of a sliding door, to name but a few examples.

Nowadays, Bowden cable arrangements of this kind are also often used in conjunction with emergency opening mechanisms, and so are used for the emergency mechanical opening of, in particular, a locking mechanism of the motor vehicle latch operated in this manner. Emergency mechanical opening of this kind is required, for example, in motor vehicle side doors when an electric motor opening drive otherwise used for the opening has failed. Bowden cable arrangements are also used to open tailgates in an emergency, i.e. from inside a trunk. In this way, people in the trunk can open it from inside. The same applies in general to cargo spaces in motor vehicles, for example light commercial vehicles.

The known Bowden cable arrangement according to DE 198 10 665 C1 has proven itself in principle and provides a solution by means of which the end of the Bowden cable sheath can be attached to a stationary retaining member simply and quickly. Since Bowden cable arrangements are today increasingly being installed on and in motor vehicle doors, motor vehicle caps, etc. for reasons of space, this results in additional requirements of firstly ensuring the core is properly sealed with respect to the sheath, and secondly of keeping the required operation forces low. This is because the Bowden cable arrangements in question are often used for emergency opening, and so manual operation that requires as little force as possible is desirable. In this respect, the previous solutions require improvement.

The technical problem addressed by the present invention is that of developing a Bowden cable arrangement of this kind for motor vehicle applications further so that the required operation forces are reduced compared with current embodiments while ensuring proper sealing between the sheath and core. To solve this technical problem for a generic Bowden cable arrangement for motor vehicle applications, the invention proposes that, in cross section, the guide region for the core has at least one point-contact site with the core. In most cases, at least two opposite point-contact sites are provided.

In this way, the core undergoes proper guidance in the axial direction at least once in the guide region of the sealing sleeve. Moreover, the two opposite point-contact sites ensure that the friction between the sealing sleeve and the core, which can move back and forth with respect thereto, is reduced overall. Generally, at least two point-contact sites spaced axially apart are provided inside the sealing sleeve. As a result, both the guidance and the sealing action of the sealing sleeve are improved in a particularly advantageous manner. In most cases, two point-contact sites spaced axially apart and two opposite point- contact sites are implemented, i.e. at total of at least four point-contact sites in the cross section. Since the sealing sleeve is generally rotationally symmetrical in relation to the flexible core guided through the center thereof, each two opposite point-contact sites define a circumferential sealing lip. Where two point-contact sites spaced axially apart and two opposite point-contact sites are implemented, two circumferential sealing lips spaced apart in the axial direction can be seen.

In this respect, the invention further, and advantageously, proposes that the guide region is limited to the two or four point-contact sites and thus to the at least one, or the two, sealing lips spaced axially apart. In principle, even more sealing lips could be provided. Overall, therefore, between the core moving inside the sealing sleeve and the sealing sleeve there is point contact, or annular contact due to the rotationally symmetrical property, only between the one or two sealing lips on one hand, and the flexible core moving back and forth with respect thereto on the other hand. This point contact or annular contact in the cross section between the sealing lip and the core firstly ensures a proper sealing action in the region of the sealing sleeve, in particular against spray water, dust, etc. present at this site. Secondly, the frictional contact in the region of each point-contact site or in the annular region of each circumferential sealing lip leads to overall improved friction conditions by comparison with the prior art.

In this regard, the invention is indeed based on the knowledge that the sealing sleeve is typically made of a flexible rubber material. This may be flexible plastics materials such as natural rubber (NR), ethylene propylene rubber (EPDM), styrene butadiene rubber (SBR) or acrylonitrile butadiene rubber (NBR), to name but a few examples. In conjunction with the additional fact that the core is preferably equipped as a steel cable having an additional plastics casing, low coefficients of friction of less than 0.4 (rubber plastics material) in the dry state, in particular even of less than 0.3, are generally observed. In conjunction with the fact that, for example, the cable friction is also dependent on the angle of wrap or, in this case, on the contact surface area, which is limited according to the invention to the point-contact sites in the cross section, considerably lower friction than in the prior art is observed in general. As a result, lower manual operating forces are also required to manually act on the Bowden cable arrangement according to the invention.

Generally, the core is produced from a steel cable, which may be one made of high-grade steel or stainless steel to prevent rust and ensure a variant with a particularly long service life. This is also aided by the fact that the steel cable is equipped with the plastics casing, which is made, for example, of polyamide (PA). It goes without saying that other thermoplastics, such as polyethylene (PE), poly(methyl methacrylate) (PMMA), polyvinyl chloride (PVC), polyurethane (PUR) and others, can also be implemented. The advantage of such thermoplastics for encasing the steel core is that they are simple, and thus cost-effective, to apply by means of overmolding. What is thus provided is a Bowden cable arrangement for motor vehicle applications that stands out on account of its particularly low-friction operation and is thus suitable and intended for the emergency mechanical opening of a motor vehicle latch or of the locking mechanism of a motor vehicle door latch. In addition to the low-friction operation, the required sealing to prevent the entry of dirt, water, etc., which can increase internal friction or cause corrosion, is observed at the same time. These are the essential advantages.

The invention will be described in more detail below on the basis of a drawing showing just one exemplary embodiment. Fig. 1 shows a Bowden cable arrangement for motor vehicle applications. Indeed, the focus here is the manual action on a motor vehicle latch 1 , which in the context of the exemplary embodiment is a motor vehicle door latch 1. By means of the Bowden cable arrangement, it is possible in this case to open a locking mechanism 2, 3 inside the motor vehicle latch or motor vehicle door latch 1 in an emergency. To do so, a handle 4 indicated in Fig. 1 generally acts on a Bowden cable 5, 6, which, in the exemplary embodiment, is composed of a sheath 5 and a core 6 that is arranged inside the sheath 5 and is movable relative to the sheath 5.

An operator can manually act on the handle 4. In most cases, this occurs when an opening drive (not shown) for the locking mechanism 2, 3 has failed or cannot be acted upon. The handle 4, and so the entire arrangement shown, are thus used for emergency opening.

On the basis of Fig. 1 , it can be seen that one end of the sheath 5 is supported against a support part 7 and the other end is supported against a further support part 8. The support part 7 may belong to a bearing device for the handle 4. On the other hand, the support part 8 corresponds to the motor vehicle latch 1. By means of the handle 4, the core 6 can be moved with respect to the supported sheath 5 in the direction of the arrow to the right (in the example), and thus directly or indirectly exerts a tensile force F on the pawl 3 as a component of the locking mechanism 2, 3.

As a result of the pawl 3 being acted upon by means of the tensile force F, the pawl 3 is removed from its engagement with the catch 2, shown in Fig. 1 , so that the catch 2 can pivot upwards and releases a locking bolt 9 previously grasped. A motor vehicle door, motor vehicle cap, etc. equipped with the shown motor vehicle latch or motor vehicle door latch 1 can be opened in this way, and specifically manually and mechanically by acting on the handle 4. Indeed, by means of the handle 4 in the exemplary embodiment (and in a non-limiting manner), the motor vehicle latch 1 is opened in an emergency from inside a trunk in the event that a person is located in the trunk and wishes to open the trunk hood equipped with the motor vehicle latch 1 in question. It goes without saying that, in principle, other applications described in the introduction to the description are possible and are included.

The end of the sheath 5 of the Bowden cable 5, 6 is equipped with a sealing sleeve 10. It can be seen that the sealing sleeve 10 is lockably coupled to an end piece 1 1 of the sheath 5. In this way, the sealing sleeve 10 can, in the example, be made of a different material from both the end piece 1 1 and the sheath 6 of the Bowden cable 5, 6. Indeed, the sealing sleeve 10 is made of a flexible rubber material, such as natural rubber (NR) or other flexible rubber materials described above in the introductory part.

Overall, the sealing sleeve 10 is rotationally symmetrical in relation to the central core 6 guided therein. In addition, the sealing sleeve 10 has a guide region 12 for the core 6, said region being arranged opposite a connection region 13 of the sealing sleeve 10 to the end piece 11. According to the invention, the guide region 12 is equipped with two point-contact sites 14 in the exemplary embodiment. Indeed, there are a total of four point-contact sites 14 in the cross section shown in Fig. 1 , and specifically at least two point-contact sites 14 spaced axially apart and two opposite point-contact sites 14. Owing to the rotationally symmetrical property of the sealing sleeve 10, the point-contact sites 14 each define a circumferential sealing lip 14. According to the exemplary embodiment, two sealing lips 14 spaced axially apart are implemented. It can also be seen that the guide region 12 is limited to the two sealing lips 14 axially spaced apart. In other words, in the guide region 12 for the core 6 there is frictional contact between the core 6 and the guide region 12 solely in the region of each sealing lip 14.

There is no additional mechanical contact between the core 6 and the sealing sleeve 10. Indeed, outside the guide region 12 the sealing sleeve 10 surrounds the core 6 at a distance, so that the core 6 is only guided inside the sheath 5 and then solely in the guide region 12 of the sealing sleeve 10. In this way, the friction in the Bowden cable 5, 6 according to the invention is optimized overall by the specially designed sealing sleeve 10, as described above in the introductory part.

Since the sealing sleeve 10 can be lockably coupled to the end piece 1 1 of the sheath 5, it is also possible, depending on the geometric design of the core 6 and in particular the diameter thereof, to select the appropriately configured sealing sleeve 10 and fit it to the end piece 11 in order to bring the two sealing lips 14 in the exemplary embodiment shown into abutment with the core 6 moving back and forth relative thereto. By means of the, as it were, dual design of the two sealing lips 14 at an axial distance from one another, the entry of dust, dirt or water between the core 6 and the sealing sleeve 10 is effectively prevented overall.

In the exemplary embodiment, the core 6 is a steel cable advantageously produced from high-grade steel or stainless steel. In addition, the core 6 advantageously has a casing made of plastics material. The plastics material used in this case is typically polyamide (PA). It goes without saying that other plastics materials stated in the introduction to the description can also be used in this context.

List of reference signs

1 Motor vehicle latch / motor vehicle door latch

2, 3 Locking mechanism

3 Pawl

4 Handle

5 Sheath

5, 6 Bowden cable

6 Core

7 Support part

8 Support part

9 Locking bolt

10 Sealing sleeve

1 1 End piece

12 Guide region

13 Connection region

14 Point-contact site / sealing lip

F Tensile force

Claims

1. Bowden cable arrangement for motor vehicle applications, in particular for manually acting on a motor vehicle latch (1 ), preferably for mechanically opening a locking mechanism (2, 3) of the motor vehicle latch (1 ) in an emergency, comprising at least one Bowden cable (5, 6) having a sheath (5) and a core (6) movable relative to the sheath (5), and comprising a sealing sleeve (10) that is arranged on at least one end of the sheath (5) and comprises a guide region (12) for the core (6), characterized in that, in cross section, the guide region (12) has at least one point-contact site (14) with the core (6).

2. Arrangement according to claim 1 , characterized in that at least two opposite point-contact sites (14) are provided.

3. Arrangement according to either claim 1 or claim 2, characterized in that at least two point-contact sites (14) axially spaced apart are provided inside the sealing sleeve (10).

4. Arrangement according to any of claims 1 to 3, characterized in that two point-contact sites axially spaced apart and two opposite point-contact sites (14) are implemented in each case.

5. Arrangement according to any of claims 1 to 4, characterized in that the guide region (12) is limited to the at least one point-contact site (14).

6. Arrangement according to any of claims 1 to 5, characterized in that the sealing sleeve (10) is rotationally symmetrical in relation to the central core (6).

7. Arrangement according to any of claims 1 to 6, characterized in that each two opposite point-contact sites (14) define a circumferential sealing lip (14).

8. Arrangement according to any of claims 1 to 7, characterized in that two sealing lips (14) spaced apart from one another in the axial direction are provided.

9. Arrangement according to any of claims 1 to 8, characterized in that the sealing sleeve (10) can be lockably coupled to an end piece (1 1 ) of the sheath (5).

10. Arrangement according to any of claims 1 to 9, characterized in that the sealing sleeve (10) is made of a flexible rubber material and the core (6) is preferably produced as a steel cable having a plastics casing made of, for example, polyamide (PA).