Opening device for a motor vehicle door

Abstract

The invention relates to an opening device for a motor vehicle door (1), said opening device being equipped with a tappet (2) and with an electromotive drive (4, 5) for the tappet (2). The electromotive drive (4, 5) acts on the tappet (2) with a drive force (F) which can vary when viewed over the travel path of the tappet (2). According to the invention, a cable-based force deflecting device (6 to 12) is provided between the drive (4, 5) and the tappet (2) in order to vary the drive force (F).

Description

[0001] Description

[0002] Opening device for a motor vehicle door

[0003] The invention relates to a positioning device for a motor vehicle door, with a plunger and with an electric motor drive for the plunger, wherein the drive operates with a drive force on the plunger that is variable over the travel path of the plunger.

[0004] Opening devices for motor vehicle doors are typically used when working with handleless motor vehicle doors. Such handleless motor vehicle doors are increasingly preferred over handle-based motor vehicle doors due to their aerodynamic advantages. If such a motor vehicle door is equipped with, for example, an electrically operated motor vehicle lock, after opening the motor vehicle lock, it is necessary to open the motor vehicle door in question, taking into account a gap or engagement gap, so that an operator can grasp the motor vehicle door through the engagement gap and, for example, swing it fully open.

[0005] It should be emphasized in this context that the term "motor vehicle door" is to be interpreted broadly in this context. This includes not only side doors pivotally attached to a motor vehicle body, but also hoods, tailgates, and even fuel tank flaps, charging port flaps, sliding doors, etc. Such opening devices for motor vehicle doors are generally known; reference is made to DE 10 2007 021 840 B4.

[0006] A fundamental problem with positioning devices arises when the required positioning force or the requested positioning time is insufficient, for example, because the associated vehicle door is iced over or otherwise blocked by the vehicle body. For this reason, the generic prior art according to DE 10 2020 124 099 A1 proposes a positioning device for a vehicle door element in which a discontinuous transmission ratio is provided by means of a gear.

[0007] In fact, an electric drive and an adjusting element acting on the door element are provided at this point. The adjusting element can be adjusted using the electric drive and the gearing arranged between the electric drive and the adjusting element. In this way, the door element can be raised using the adjusting element. The implemented gearing with a discontinuous transmission ratio consists of two interacting levers.

[0008] In another and also generic setting device, as described in DE 10 2021 131 149 A1, a force transmission device acting on the plunger ensures overall that an opening force for the plunger provided thereby is designed to decrease over at least a range of the extension movement of the plunger.

[0009] In one embodiment, a cable pulley is used, with the power transmission device being equipped with a tension element connected to the motor drive. In this way, a rotating transmission element can be driven. While this generally results in a force redirection of the associated cable, this does not change the drive force acting on the ram; rather, it merely undergoes a redirection.

[0010] In a similarly functioning opening device for a motor vehicle door, as described in DE 102019 128 986 1, the electric motor drive operates with the aid of a control element, taking into account a first range of motion toward the motor vehicle door in a first direction and, in a second range of motion, in a second direction opposite to the first direction. The prior art has generally proven itself, but still offers room for improvement. For example, the prior art predominantly uses gear arrangements or relatively complex lever geometries to provide the modified drive force. Such gear arrangements and specific lever geometries have the general disadvantage that manufacturing is relatively complex.If, for example, plastic is to be used as a material in order to keep weight and costs low, functional impairments must also be feared, especially when working with high loads, such as those inevitably encountered in a so-called "icebreaker function." This is where the invention aims to remedy the situation.

[0011] The invention is based on the technical problem of further developing such a positioning device for a motor vehicle door in such a way that a simple structure is provided taking into account a functionally appropriate design while at the same time realizing a variable drive force.

[0012] To solve this technical problem, the invention proposes, starting from a generic positioning device for a motor vehicle door, that a cable-based force deflection device is provided for varying the drive force between the drive and the tappet.

[0013] According to the invention, the cable-based force deflection device ensures that the drive force provided by the electric motor drive for the axial adjustment of the ram can be varied. For this purpose, the force deflection device is provided between the electric motor drive and the ram.

[0014] Advantageously, the force deflection device is a pulley block with at least one stationary cable pulley and one loose cable pulley. The invention is based on the finding that with the aid of a pulley block, the drive force available on the output side for the axial adjustment of the tappet can be easily changed, in particular increased, when the electric motor drive encounters an increased load on the output side on the tappet. This is the case, for example, when the motor vehicle door, which is to be opened with the aid of the tappet, is "frozen" or otherwise blocked relative to the vehicle body. In this case, the force deflection device, which is advantageously designed as a pulley block according to the invention, operates with a modified and preferably enlarged orvariable or increaseable driving force on the ram, so that such load cases can also be controlled and, in particular, an "icebreaker function" can be realized.

[0015] To realize and implement this in detail, two stationary pulleys of different diameters are usually provided. The two stationary pulleys can be connected to a drive pulley meshing with an electric motor, forming both components of the drive system.

[0016] This means that the drive essentially consists of the electric motor and the drive pulley meshing with the electric motor. The two stationary pulleys of the force deflection device or pulley block are connected to the drive pulley. This is usually done so that the two pulleys and the drive pulley form a structural unit that can rotate around a common axis. This structural unit can advantageously be designed as a plastic injection-molded part for cost and weight reasons. Of course, a structural unit designed as a metal injection-molded part is also conceivable and is encompassed by the invention.

[0017] The free pulley, in contrast, is generally rotatably connected to the ram. Accordingly, the free pulley is moved together with the ram when the ram undergoes the desired axial movement with the aid of the electric motor drive and the interposition of the force deflection device. In fact, the ram is regularly moved back and forth in its longitudinal direction and consequently in the axial direction, namely between a retracted and an exposed or raised position, as will be explained in more detail below with reference to the description of the figures.

[0018] In this context, it is advantageous to proceed in such a way that the loose cable pulley, which is rotatably connected to the tappet, is elastically supported by a return spring. For this purpose, the return spring is connected to the tappet.

[0019] In this context, the return spring is usually designed as a spiral spring, with one end connected to the plunger and the other end to a bearing plate that rotatably supports the loose sheave. Thus, the force of the return spring ensures that, after, for example, a load is applied to a rope guided over the rollers, the plunger is returned by the electric motor drive, and any compensation of the rope tension and rope length can be achieved.

[0020] In addition, an additional sheave is usually provided to deflect the respective rope toward a fixed point at the end of the rope. The other fixed point of the rope is usually located on the stationary sheave. Accordingly, the rope is guided from the stationary sheave via another stationary sheave, then the loose sheave on the ram, and finally the additional sheave for deflection to the other fixed point at the end. This additional sheave is advantageously supported elastically and optionally by an overload protection spring and, if necessary, by an overload protection coupling. This additional sheave is thus designed as a quasi-stationary sheave.

[0021] As long as the drive force transmitted to the ram via the cable of the force-transfer device does not exceed a certain value, the quasi-stationary cable pulley maintains its (fixed) position. The overload protection spring is extended in this case. An overload force can be defined using the optional overload protection coupling. The overload protection spring is usually a spiral spring, which in this case is at its almost unloaded length.However, if an overload occurs and, for example, the plunger equipped with the loose cable pulley can no longer be moved in its axial direction due to a possible blockage of the vehicle door (because the vehicle door is frozen, for example), this increased load leads to the overload protection spring being compressed and the other quasi-stationary cable pulley moving together with the increasingly compressed overload protection spring in the direction of the adjacent fixed point of the cable.

[0022] This increase in load generally results in the rope jumping from one stationary sheave to the other. This is usually achieved by a ramp or transfer ramp connecting the two stationary sheaves.

[0023] The design is usually such that the two stationary sheaves are equipped with different diameters, for example, one large (diameter) and one small (diameter). The rope is initially guided from the large sheave with its fixed point over the loose sheave on the ram to move the ram in its axial direction. If the load applied to the ram increases, the overload protection spring is compressed. Subsequently, and with an even higher load, the transfer ramp between the large stationary sheave and the small stationary sheave ensures that the rope jumps to the small sheave.

[0024] Assuming the same torque is supplied to the drive pulley by the electric motor, the drive force exerted on the rope increases due to the lever shortening associated with the transition of the rope to the smaller pulley. This can be several times greater. For example, if the two stationary pulleys have a diameter ratio of 1:5 (small pulley compared to large pulley), the jump from the large pulley to the small pulley results in a fivefold increase in the available drive force in the rope. This is, of course, only an example and is by no means limiting.

[0025] In any case, overall and according to the invention, a positioning device for a motor vehicle door is provided, which generally uses the cable-based force deflection device and, in particular, the pulley system to ensure the axial loading of the tappet. Such a cable-based force deflection device has the fundamental advantage that its construction is simple and can be implemented and, in particular, does not require any precision components. Furthermore, blockages are practically unobservable.

[0026] In fact, the sheaves used can be made of plastic, making them both cost-effective and lightweight. The same applies to the rope, which can also be made of plastic. In addition, such a rope-based force deflection device is characterized by functionally correct operation, as it only requires the guidance of the rope and sheaves, thereby preventing any mechanical blockages or jamming. Furthermore, the additional overload protection spring virtually eliminates damage.

[0027] The additional, optional return spring also ensures that any sagging or signs of aging in the cable can be automatically compensated for, which is not possible with lever- or gear-based units described in the prior art due to their design. This is the key advantage. The invention is explained in more detail below using a drawing that represents only one exemplary embodiment. It shows:

[0028] Fig. 1 shows the inventive positioning device for a motor vehicle door in a plan view and

[0029] Fig. 2 shows the object according to Fig. 1 in a schematic side view.

[0030] The figures depict a positioning device for a motor vehicle door 1. Indeed, the exemplary embodiment in Fig. 1 clearly shows that the positioning device is located inside the motor vehicle door 1. For this purpose, the positioning device is essentially equipped with a plunger 2. The plunger 2 can be moved in its axial direction A, indicated in Fig. 1, using the positioning device. This causes the plunger 2 to move (to the "right") against a motor vehicle body 3.

[0031] If the motor vehicle door 1 is, by way of example and not limitation, a pivoting motor vehicle side door, the plunger 2, which moves against the motor vehicle body 3, ensures during a positioning process that the motor vehicle door 1 is positioned relative to the motor vehicle body 3, taking into account a specific gap or engagement gap. An operator can grasp the motor vehicle door 1 via the engagement gap and pivot it completely open. This allows the motor vehicle door 1 to be designed without handles, as already described at the beginning.

[0032] In addition to the previously mentioned plunger 2, the basic design of the positioning device also includes an electric motor drive 4, 5 for the plunger 2. This means that the plunger 2 is caused to perform axial movements in the axial direction A with the aid of the electric motor drive 4, 5. For this purpose, the electric motor drive 4, 5 essentially consists of an electric motor 4 and a drive disk 5 that meshes with the electric motor 4. According to the exemplary embodiment and the invention, the electric motor drive 4, 5 ensures that the drive force F provided by the drive 4, 5 and acting on the plunger 2 is variable, as will be explained in more detail below.

[0033] In fact, the design is such that the drive force F is varied by means of a cable-based force deflection device 6, 7, 8, 9, 10, 11, 12 arranged between the electric motor drive 4, 5 and the plunger 2. This means that, according to the invention, the cable-based force deflection device 6 to 12 ensures the variation of the drive force F between the drive 4, 5 and the plunger 2.

[0034] For this purpose, the rope-based force deflection device 6 to 12 is designed as a pulley block 6 to 12 with at least one stationary pulley 6, 7 and a loose pulley 10. In fact, two stationary pulleys 6, 7 of different diameters Di, D2 are implemented at this point. One can see a large (diameter) pulley 6 and a small (diameter) pulley 7. This is clearly shown in the side view in Fig. 2, where the respective diameters Di for the large (diameter) pulley 6 and D2 for the small (diameter) pulley 7 are shown. The ratio of the diameters Di : D2 is:

[0035] D2: Di = 1 : 4.

[0036] This is, of course, only an example. Furthermore, a transfer ramp 8 connecting the two pulleys 6 and 7 can be seen. Using the transfer ramp 8, the rope 12 can, for example, be transferred or jumped from the large (diameter) pulley 6 to the small (diameter) pulley 7. This typically occurs when a high load is applied to the ram 2, as explained in more detail below.

[0037] The two fixed sheaves 6, 7 together with the transfer ramp

[0038] According to the exemplary embodiment, the drive pulley 8 and the drive pulley 5 are designed as a structural unit 5, 6, 7, 8. This can be an injection-molded part made of plastic or metal. Furthermore, the aforementioned pulleys 5, 6, 7 are designed to rotate about a common central axis.

[0039] In addition, the force deflection device or pulley block 6 to 12 also has a stationary pulley 9, which is essentially unnecessary, via which the rope 12 is deflected from a fixed point Pi on the stationary pulley 6, 7, specifically on the (diameter) large pulley 6, toward a loose pulley 10. The loose pulley 10 is rotatably connected to the ram 2. Furthermore, the loose pulley 10 is elastically supported by a return spring 13, which is also connected to the ram 2.

[0040] In fact, the design is such that the return spring 13 is constructed as a spiral spring and is connected at one end to the plunger 2 or is supported against the plunger 2. The other free end of the return spring 13, in contrast, rests against a movable bearing plate 14, which, on the one hand, rotatably supports the loose cable pulley 10 and, on the other hand, is designed to be movable in the axial direction A relative to the plunger 2. Thus, the return spring 13 can compensate for any elongation of the cable 12 or support the return movement of the plunger 2 after a movement process.

[0041] Additionally and essential, another pulley 11 is provided, over which the rope 12 is redirected from the loose pulley 10 until another fixed point P2 of the rope 12 is reached. The additional pulley 11 is elastically supported by an overload protection spring 15. According to the exemplary embodiment, an overload protection clutch 16 is optionally provided. Using the overload protection clutch 16, the overload protection spring 15 can be relieved if necessary, and an overload force can be defined.

[0042] The other fixed point P2 of the rope 12 is fixedly connected to a housing or other means. Furthermore, a detent or notch for the additional rope pulley 11 can also be provided in this context. Since the rope pulley 11 in question is elastically supported by the overload protection spring 15 and is moved with its free end, the rope pulley 11 in question is a quasi-stationary rope pulley 11, as will be explained in more detail below.

[0043] The mode of operation is as follows. Starting from the functional position in Fig. 1, in which the cable 12 is guided from one fixed point P1 via the large cable pulley 6 and then the stationary cable pulley 9 to the loose cable pulley 10 via the quasi-stationary cable pulley 11 to the second fixed point P2, a counterclockwise movement of the drive pulley 5 and thus of the structural unit 5, 6, 7, 8, initiated by the electric motor drive 4, 5, ensures that the tappet 2 is moved towards the motor vehicle body 3 (to the right) with the drive force F. The drive force F is provided by the electric motor 4 and results from the essentially constant torque generated at the drive pulley 5 in conjunction with the large cable pulley 6.

[0044] If, in such a case, the plunger 2 is subjected to a load, for example, because the plunger 2 has moved against the vehicle body 3 but cannot be extended further because the vehicle door 1 is frozen shut, this initially leads to the loose cable pulley 10, in the exemplary embodiment, being moved "to the right" in an unchanged manner by the drive force F. Together with the loose cable pulley 10, the plunger 2 is also moved "to the right" in a constant manner.

[0045] If the applied load becomes greater than the counterforce provided by the overload protection spring 15, the overload protection spring 15 is compressed until the cable 12 jumps from the large cable pulley 6 to the small cable pulley 7 with the help of the transfer ramp 8. Before this, the quasi-stationary cable pulley 11 has moved from its initially assumed "stationary" state together with the free end of the overload protection spring 15 "to the left". The cable pulley 7 corresponds to the diameter D2, which is smaller by a factor of 4 than the original diameter Di of the large cable pulley 6. As a result of this, the driving force F on the tappet 2 increases by a factor of 4 and in this way, in the example case, the layer of ice blocking the vehicle door 1 can now be broken through (icebreaker function). I.e., viewed over the travel path of the plunger 2, the change in the driving force F occurs, according to the exemplary embodiment, in that the driving force F is quadrupled. This is accompanied by a change in the diameter of the stationary pulley 6, 7 from the initially relevant diameter Di to the comparatively smaller diameter D2.

[0046] The motor vehicle door 1 is thus completely released from the motor vehicle body 3 and is raised by the desired amount until the previously described engagement gap is available. An operator can now grasp the motor vehicle door 1 through the engagement gap and raise it completely relative to the motor vehicle body 3. The overload protection spring 15 relaxes, and the return spring 13 ensures that the cable 12 remains under the same tension after this process. Furthermore, the return spring 13 can assist the return movement of the plunger 2 from its extended position corresponding to the raised position of the motor vehicle door 1.

[0047] List of reference symbols

[0048] Motor vehicle door 1

[0049] Tappet 2

[0050] Motor vehicle body 3

[0051] Electric motor 4

[0052] Drive pulley 5

[0053] Drive 4, 5

[0054] Pulley 6, 7

[0055] Unit 5, 6, 7, 8

[0056] Transfer ramp 8

[0057] Force deflection device 6, 7, 8, 9, 10, 11, 12

[0058] Pulley 9

[0059] Rope pulley 10

[0060] Pulley 11

[0061] Rope 12

[0062] Return spring 13

[0063] Bearing plate 14

[0064] Overload protection spring 15

[0065] Overload protection clutch 16

[0066] Axial direction A

[0067] Driving force F

[0068] Fixed point Pi, P2

[0069] Diameter Di , D2

Claims

Patent claims 1. A device for opening a motor vehicle door (1), comprising a plunger (2) and an electric motor drive (4, 5) for the plunger (2), wherein the drive (4, 5) operates with a drive force (F) on the plunger (2) that is variable over the travel path of the plunger (2), characterized in that a cable-based force deflection device (6 to 12) is provided for varying the drive force (F) between the drive (4, 5) and the plunger (2).

2. Device according to claim 1, characterized in that the force deflection device (6 to 12) is designed as a pulley (6 to 12) with at least one fixed pulley (6, 7) and one loose pulley (10).

3. Device according to claim 2, characterized in that two stationary pulleys (6, 7) of different diameters (Di, D2) are provided.

4. Device according to claim 2 or 3, characterized in that both stationary pulleys (6, 7) are connected to a drive pulley (5) meshing with an electric motor (4) as both components of the drive (4, 5).

5. Device according to claim 4, characterized in that the two cable pulleys (6, 7) and the drive pulley (5) define a structural unit (5, 6, 7, 8) rotatable about a common axis, for example a plastic injection-molded part.

6. Device according to one of claims 2 to 5, characterized in that the loose pulley (10) is rotatably connected to the tappet (2).

7. Device according to claim 6, characterized in that the loose pulley (10) is elastically supported on a return spring (13) connected to the plunger (2).

8. Device according to one of claims 1 to 7, characterized in that a further pulley (11) is provided for deflecting a rope (12) toward a fixed end point (P2) of the rope (12).

9. Device according to claim 8, characterized in that the further cable pulley (11) is supported elastically on an overload protection spring (15) and optionally on an overload protection clutch (16) and is designed as a quasi-stationary cable pulley (11).

10. Device according to one of claims 1 to 9, characterized in that another fixed point (Pi) of the rope (12) on the stationary pulley (6, 7) is provided for.

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