EP0478931B1 - Actuating mechanism with positioning through automatic interlocking - Google Patents

Description

The invention relates to an adjustment drive, in particular a motor vehicle window lift drive, with adjustment positions that can be fixed by self-locking, according to the preamble of claim 1; such an adjustment drive is known from DE-A-36 14 671.

From DE-A-36 14 671 an adjustment drive for a motor vehicle window lifter with a device is known, through which the window pane can be pushed up or down on the one hand by a crank on the inside of the door, but on the other hand prevented that the window pane by external influences can be pushed up or down or subsides under the influence of gravity; For this purpose, a drive plate with two axial projections for engagement with two clamping arms is fastened on a shaft rotatably mounted within a cylindrical housing, one end of which is pivotably held on a pivot pin on a hinge pin below the fulcrum of the shaft and the other free ends above which Pivot point by a spring with an end surface corresponding to the shape of the cylindrical housing against the housing. In the event of an unintentional opening movement of the disk, the end face of one of the clamping arms is pressed against the cylindrical face of the cylindrical housing by means of a movement via the gear wheel and the articulated pin and is blocked in its position by appropriate adjustment of the spring.

In an adjustment drive known from DE-U-89 03 714 for an electric motor-driven cable window lifter the elongated rotor shaft of an electric drive motor protrudes as a worm shaft into a gear housing flanged to the motor housing and meshes with the worm wheel; the worm wheel is in driving connection with a rope pulley with cables leading to a window pane driver. The worm wheel is rotatably mounted on an axis, which is fastened with one end in the pot bottom of the gear housing. A driving pulley, which is also rotatably mounted on the axis and which is inserted with axially protruding driving cams distributed over its circumference with the interposition of damping intermediate layers in corresponding driving pockets of the worm wheel, is used for the rotational driving between the worm wheel on the one hand and the pulley provided as the output. In order to be able to ensure in this known motor vehicle window lifter drive that a window pane previously brought into a certain adjustment position does not move back by itself or in an undesired manner due to other forces, the transmission connected downstream of the electromotive drive is designed to be self-locking; This means that the efficiency of the transmission must not be better than 50%, so that sufficient self-locking is still ensured.

In a drive device known from DE-A-29 11 024 with a gear motor for adjusting window panes, sunroofs and the like. The like. From motor vehicles, a worm wheel on the drive side is available in axially concentric driving with a driver that can be coupled to an output shaft. To prevent an unwanted opening movement, a positive self-locking can be locked by means of a ring gear in a rotating gear housing Pawl provided in such a way that, on the one hand, it engages in the sprocket with both the motor-side drive and the output-side drive, the pawl sliding in the form of a ratchet in the form of a ratchet over the teeth of the ring gear in the one direction of rotation (lifting) and in the other Direction of rotation (lowering) is released against the spring pressure by a stop cam or, in the case of a drive on the output side, is pressed in this direction of rotation (lowering) by the spring pressure in the sense of a positive self-locking in the ring gear.

In contrast, a construction which is simpler in terms of component and assembly effort and nevertheless fully operational, in particular self-reinforcing self-locking in the event of unwanted movement of the window pane, can be achieved in a generic adjustment drive by the teaching according to the characterizing part of claim 1.

In the case of the adjustment drive according to the invention, self-reinforcing self-locking in the event of unintentional resetting of the adjustment drive from a previously approached adjustment position and thus compared to drives with a gear inhibition according to DE-U-89 03 714 or compared to drives according to DE- A- 3.614 671 a maximum efficiency of the gearbox with a correspondingly increased output power of the drive or with constant output power correspondingly lower electromotive drive power or compared to solutions according to DE-Al-38 38 285 with less expenditure on components a self-reinforcing self-locking can be achieved without a correspondingly designed pressure spring.

In the case of an adjustment drive with at least one first, one direction of rotation and at least one second, associated with the other direction of rotation grinding brake lever with the worm shaft side drive in one direction of rotation before the assigned to the other direction of rotation brake lever with its free end through the worm wheel from the braking surface.

The drive connection between the worm wheel on the one hand and the coaxial driver on the other hand expediently takes place in each direction of rotation by means of at least one driving arm on one component, for example the worm wheel, and a corresponding driving fork with play on the other component, for example the driver. On separately manufactured and assembled damping means for cushioning the stroke between the worm wheel on the one hand and the driver on the other can be dispensed with if, according to a special embodiment of the invention, the driving arms or the driving forks are fastened to the worm wheel or to the driver in the sense of a spring arm or are injection-molded in one piece from plastic.

In order to be able to guarantee sufficient adjustability of the grinding brake levers in a self-reinforcing self-locking, even with longer operating times, taking into account material wear between the grinding surface or the braking surface of the gearbox housing, and taking into account the manufacturing tolerances, the grinding brake levers are pivotably mounted in the driver as discrete components . A design that nevertheless keeps the component and assembly effort low is due to a pivotable mounting of the grinding brake levers made of plastic as discrete components in the driver and each integrally molded onto the grinding brake lever or the driver with one end and with the other end the driver or the grinding brake levers supporting pressure springs.

In order to be able to guarantee sufficient and uniform self-reinforcing self-locking over long service lives, despite the large swivel range of the grinding brake levers and taking into account tolerance specifications and wear, a smaller concave curvature of the braking surface on the gearbox housing side compared to the corresponding convex grinding surface of the grinding brake levers in terms of a mutual pressure angle β which is smaller than the friction angle ρ of the materials of the braking surface and grinding surface, in particular a curve of the grinding surface corresponding to a logarithmic spiral.

FIG 1

in einem radialen Teilschnitt den grundsätzlichen Aufbau eines Getriebegehäusegehäuses mit integrierter Selbsthemmung,

FIG 2

den axialen Längsschnitt zur Anordnung gemäß FIG 1,

FIG 3

in einem radialen Teilschnitt eine erste Alternativausführung zur Anordnung gemäß FIG 1,

FIG 4

in einem radialen Teilschnitt eine zweite Alternativausführung zur Anordnung gemäß FIG 1,

FIG 5

in stirnseitiger Draufsicht einen Mitnehmer mit drei darin schwenkbar gelagerten Schleifbremshebeln mit jeweils einstückig angespitzter Andruckfeder,

FIG 6

die Anordnung gemäß FIG 5 im Schnittverlauf VI-VI, jedoch in einer Vormontagestellung,

FIG 7

in stirnseitiger Draufsicht einen einzelnen Schleifbremshebel mit einem Krümmungsverlauf seiner Schleiffläche entsprechend einer logarithmischen Spirale,

FIG 8

in radialer Draufsicht einen Teil der Bremsfläche der getriebegehäuseseitigen Bremsfläche mit einem Querrippen-Bremsprofil.

The invention and further advantageous refinements of the invention according to the features of the subclaims are explained in more detail below with reference to schematically illustrated exemplary embodiments in the drawing; show in it:

FIG. 1

in a radial partial section, the basic structure of a gearbox housing with integrated self-locking,

FIG 2

the axial longitudinal section for the arrangement according to FIG 1,

FIG 3

in a radial partial section, a first alternative design for the arrangement according to FIG. 1,

FIG 4

in a radial partial section, a second alternative embodiment to the arrangement according to FIG. 1,

FIG 5

in a top view from the front, a driver with three grinding brake levers pivotably mounted therein, each with a one-piece tip pressure spring,

FIG 6

5 in the section VI-VI, but in a pre-assembly position,

FIG 7

a top view of a single grinding brake lever with a curve of its grinding surface corresponding to a logarithmic spiral,

FIG 8

a radial top view of part of the braking surface of the transmission housing-side braking surface with a transverse rib braking profile.

2 shows the axial longitudinal section of the transmission of a motor vehicle window lifter with a cup-shaped transmission housing 1, which can be closed by a transmission housing cover 1.1. A gear housing axis 1.2 is fastened in the pot bottom of the gear housing 1, on which a worm wheel 2 and a driver 3 are rotatably mounted. On the right outer end of the driver 3, for example, the cable pulley of a cable window lifter can be attached as an output. The worm wheel 2 is driven by a worm shaft 9, which is an extended rotor shaft of an electric motor flanged to the gear housing 1 projects into the gear housing 1. For a further explanation of the self-locking according to the invention, reference is first made to FIG. 4, which shows an embodiment with discrete grinding brake levers 4 and 5, which are pivotably mounted in the driver 3.

For driving between the worm wheel 2 and the driver 3 with a worm shaft side, i.e. Motorized drive of the window lifter serve radially inward from the worm wheel 2 driving arms 2.1 or 2.2, which project with tangential play in driving forks 3.1 or 3.2 of the driving 3. The driving arm 2.1 is assigned the grinding brake lever 4, which serves for self-locking when the driver 3 attempts to move the driver 3 in the counterclockwise direction n2. In an analogous manner, the further grinding brake lever 5 is assigned to the driving arm 2.2 if the worm wheel 2 is assumed to have an operational electric motor drive counterclockwise n2 and a self-locking drive on the output side clockwise n1.

Between the grinding brake levers 4 and 5, on the one hand, and the driving arms 2.1 and 2.2, on the other hand, release pins 41 and 51, preferably connected in one piece to the grinding brake levers 4 and 5, are provided, such that when the worm wheel 2 is driven on the worm shaft side, for example clockwise n1, before the driver 3 is taken along by the driving arms 2.1 or 2.2, only the driving arm 2.2 comes to rest against the release pin 51 of the grinding brake lever 5 assigned to it and releases it from the braking surface 1.3; Accordingly, the tangential play between the driving arms on the one hand and the overarching driving forks on the other hand and a point of engagement of the disengaging pins which is eccentric to the pivot point of the grinding brake lever must be provided on their assigned grinding brake lever.

Pressure springs 7 and 8, respectively, which are plugged onto pins 3.5 and 3.6 on the driver side only serve to rub the braking ends of the grinding brake levers 4 and 5, respectively, against the braking surface 1.3 if they are not released or pressed against the braking surface in a self-locking manner. The braking surface 1.3 is formed in a simple manner in terms of production technology from the transmission housing cover 1.1 in the form of a brake drum. Gear housing and / or gear housing cover can be injection molded from plastic or metal or formed from sheet metal.

Now e.g. the worm wheel 2 is driven by the electric motor drive of the window lifter via the worm shaft 6 in the clockwise direction n1, the worm wheel 2 moves relative to the driver 3 until the clearance between the driver arm 2.1 or 2.2 and the driver fork 3.1 or 3.2 of the driver arm 2.1 is overcome or.2.2 touches the driver 3 and takes it clockwise n1. The grinding brake lever 4 assigned to the driving arm 2.1 grinds with a slight pressure of its free end against the braking surface 1.3 determined by the pressure spring 7 during the intended electromotive-driven movement of the worm wheel 2 and accordingly of the driver 3 in the direction of rotation n1. Advantageously, the play between the driving arms and the driving forks is such that the driving of the driving 3 by the worm wheel 2 is only possible when the grinding brake lever 5, which is grinding in the other direction of rotation n2, through the driving arm 2.2 assigned to it via the other release pin 51 is released against the pressure of the pressure spring 8 with its free end from the braking surface 1.3.

The pressure springs 7 and 8 each only have to exert sufficient pressing force that the grinding brake levers 4 and 5 always rest securely on the braking surface 1.3 when the worm wheel 2 or the driver 3 is electromotively driven by the worm shaft.

For self-locking of the window lifter drive according to the invention in the event of a backward movement in the counterclockwise direction n2 starting from the driven side of the driver 3, the grinding brake lever 4 is carried by the driver 3 before the driver 3 with its driver fork 3.1 or 3.2 comes to rest against the driver arm 2.1 or 2.2 its free end pressed against the braking surface 1.3 with self-reinforcing braking action; for this purpose - as can be seen from FIG. 4 - the grinding brake lever 4 is rotated with an angle of attack α with respect to its central radial angle, which is smaller than the angle of friction. As a result, a self-locking braking position is instantaneously achieved, which prevents further backward movement of the window lift drive and thus an unwanted leaving of the previously retracted adjustment position of the window lift drive.

FIG 1.3 shows two constructions of the self-locking device according to the invention which require less construction and, in particular, assembly technology. For this purpose, the grinding brake levers 4 and 5 are advantageously integrally molded in one piece on the driver 3 as a support pressure means and thus without separate pressure springs, the respective release pins 41 and 51 also expediently also being integrally molded on. While the driving arms 2.1; 2.2; 2.3; 2.4 at their worm wheel-side ends in the form of a pin into worm wheel 2, fork-shaped transitions are provided according to FIG.

In all of the exemplary embodiments, the driving arms 2.1 or 2.2 or 2.3 or 2.4 are advantageously formed as one-piece components of the worm wheel 2, which is preferably injection molded from plastic, and in particular in the sense of a resilient, in particular shock-absorbing driving between the worm wheel 2 and the driver 3; this means that there is no need for separate intermediate damping layers between the worm wheel 2 on the one hand and the driver 3 on the other.

In order to be able to support a locking position of the grinding brake levers 4 or 5 or 6 with respect to the gear housing-side braking surface 1.3 at the beginning of a self-reinforcing self-retention, according to one embodiment of the invention, the braking housing 1.3 on the gear housing side with the grinding surface 4.3 or 5.3 or 6.3 of the grinding brake levers 4 or 5 or 6 open transverse recesses 1.31 or 1.32, into which the material of the grinding brake lever can be molded by a small amount at the beginning of a self-reinforcing self-holding position. Advantageously, two different profiles are provided for each of the transverse recesses such that a wider and deeper braking profile 1.3 is provided over a larger axial extent and a smaller running profile with a smaller opening width in particular in the grinding direction is provided in a smaller part of the transverse recess. This different profiling ensures that when the driver 3 is operationally driven, the grinding brake levers which grind on the gearbox-side brake surface 1.3 with slight spring pressure can be moved quietly on the one hand due to the smaller running profile, but on the other hand when attempting to move counterclockwise due to the larger braking profile, the grinding brake levers are better fixed to initiate self-reinforcing self-retention by slight molding in the transverse recesses.

5 shows the front plan view of a driver 3 with three grinding brake levers 4, 5 and 6, respectively, which are pivotally distributed over the circumference. For pivotable mounting, each grinding brake lever has an integrally molded pivot pin 4.4 or 5.4 or 6.4, which is inserted into a corresponding pin receptacle in the driver 3. Each grinding brake lever 4 or 5 or 6 is pivotable in recesses of the driver 3 between tangential stops 3.8 on one side and 3.9 on the other side. The grinding surfaces 4.3 or 5.3 or 6.3 of the grinding brake levers have a larger curvature than the respective braking surface 1.3 of the gear housing 1; Preferably, a smaller concave curvature of the gearbox-side braking surface 1.3 is provided in comparison to the corresponding convex grinding surface 4.3 or 5.3 or 6.3 of the grinding brake levers 4 or 5 or 6 in the sense of a mutual pressure angle β which is smaller than the friction angle ρ of the materials from Braking surface 1.3 on the one hand and grinding surface 4.3 or 5.3 or6.3 on the other. To achieve self-reinforcing self-locking, the pivot point of the pivot pins 4.4 or 5.4 or 6.4 of the grinding brake levers 4 or 5 or 6 lies between the pivot point of the driver 3 on the one hand and the contact point of the grinding brake levers on the gearbox-side brake surface 1.3, but outside the direct connecting line between the pivot point of the driver 3 and the contact point between the grinding surface of the grinding brake levers and the braking surface on the transmission housing side.

Such a pivoting arrangement of the grinding brake levers on the one hand or the design of the grinding or braking surfaces on the other hand ensures that even taking into account manufacturing and assembly tolerances or wear of the grinding or braking surfaces an automatic readjustment of the grinding brake levers and in any case a safe one self-reinforcing self-locking are guaranteed when the driver 3 moves counter to its operationally motor-driven direction of rotation.

As can be seen in particular from FIG. 5 and FIG. 7, pressure springs 4.2 or 5.2 or 6.2 are integrally formed on the grinding brake levers 4 or 5 or 6, in particular when molded from plastic. In order to reduce the outlay on components and assembly, as in FIG. 6 in particular can be seen - provided according to an embodiment of the invention that the driver 3 on the one hand and the grinding brake lever 4 or 5 or 6 with the integrally molded pressure spring 4.2 or 5.2 or 6.2 on the other hand parts of a in a single injection mold initially as separately sprayable and demoldable and then, preferably in the injection mold, by one-piece assembly component that can be provided by axially plugging together. 6 shows the grinding brake lever 4 with its pivot pin 4.4 when the injection mold is still a component separate from the driver 3, in that after the injection molding compound has hardened, it can still be inserted into the pivot pin receptacle by an engagement movement in the injection mold.

5 shows the grinding brake levers 4 and 6 with pressure springs 4.2 and 6.2, integrally molded thereon, before the springs are hooked in, while the pressure spring 5.2 of the grinding brake lever 5 is already suspended with its free end behind an associated fixed point 3.7 on the driver 3.

The pressure springs 4.2 or 5.2 or 6.2 only serve to make a sliding contact of the grinding surfaces 4.3 or 5.3 or 6.3 of the grinding brake levers 4 or 5 or 6 on the gearbox housing side in the operational direction of rotation of the drivers 3 driven clockwise by the motor drive To ensure braking surface 1.3; an additional function for self-reinforcing self-locking of the grinding brake levers when the driver 3 moves counterclockwise does not apply to the pressure springs. The desired determination of the driver 3 then takes place solely through the toggle lever swivel arrangement of the grinding brake levers relative to the driver 3 on the one hand and to the brake surface 1.3 on the transmission housing side on the other hand.

With a clockwise motor drive, each grinding brake lever grinds lightly on the braking surface; at a Motor drive counterclockwise - as already described with reference to FIG. 3.4 - first each grinding brake lever is lifted slightly from the braking surface in that the driving arms of the worm wheel before it actually drives the driver 3 are initially in contact with the release pins 4.1 or 5.1 or 6.1 come. In both directions of rotation, a free movement of the driver 3 relative to the braking surface 1.3 on the transmission housing side is thus ensured in the case of a motor drive.

However, if an unwanted opening is attempted by external external influences on the window pane, which would correspond to a movement of the driver 3 coupled to the rope pulley for driving the window, a self-reinforcing self-locking effect immediately occurs due to the toggle lever action of the grinding brake lever.

Claims (18)

1. An adjusting drive, in particular a motor vehicle window lifter drive, with adjusting positions able to be fixed by automatic locking, the output of which is in drive connection in a gear housing (1) with a rotor driven by way of a drive shaft, by way of a driver member (3) mounted coaxially thereto, with, in each direction of rotation at least one sliding brake lever (4 or 5 or 6) pivoted with its one end in the driver member (3), mounted coaxially to the rotor, such that, with the drive on the drive shaft side, it is able to be driven in each case by the driver member (3) in a sliding manner with its other free end over a gear housing-side brake surface (1.3), coaxial to the driver member (3), and, with the opposing drive on the output side, is able to be applied against the brake surface (1.3) in a self-locking manner,
   characterised in that the swivel point of the sliding brake lever (4 or 5 or 6) lies, according to the toggle principle, in each case between its bearing point on the gear housing-side brake surface (1,3), on the one hand, and the centre of rotation of the driver member (3), on the other hand, outside the direct connecting line between the bearing point and the centre of rotation and in that the drive shaft is formed as a worm shaft (9) and the rotor as a worm wheel (2)
2. An adjusting drive, according to claim 1, characterised in that the worm shaft (9) engaging with the worm wheel (2) is an extended motor shaft driven by a motor and projecting into the gear housing.
3. An adjusting drive according to claim 1 or 2, characterised in that at least a first sliding brake lever (4) associated with one direction of rotation (n1) and at least a second sliding brake lever associated with the other direction of rotation (n2) are provided and in that with the drive on the worm shaft side in one direction of rotation (n1) the sliding brake lever (5) associated with the other direction of rotation (n2) is able to be raised from the brake surface (1.3) with its free end by means of the worm wheel (2). (Figures 3,4)
4. An adjusting drive according to one of claims 1-3, characterised by a drive connection between the worm wheel (2) and the coaxially mounted driver member (3) by means of at least in each direction of rotation one driver member arm (2.1 or 2.2) on the one component (worm wheel 2) and a corresponding driving fork (3.1 or 3.2) overlapping with clearance, on the other component (driver member 3). (Figures 3,4)
5. An adjusting drive for both directions of rotation n1 or n2 according to claim 4, characterised by a clearance in the sense of a drive connection between the driving arms (2.1 or 2.2) and the driving forks (3.1 or 3.2) thereof, once the one sliding brake lever (5), otherwise applied against the brake surface (1.3) in a self-locking manner by way of the drive member (3), has been raised. (Figures 3,4)
6. An adjusting drive according to claim 5, characterised by a pivot drive of the sliding brake lever (4 or 5) in the sense of raising from the brake surface (1.3) by means of the worm wheel-side driving arm (2.1 or 2.2) or the worm wheel-side driving fork (3.1 or 3.2) by way of a disengaging pin (4.1 or 5.1). (Figures 3,4)
7. An adjusting drive according to claim 5, characterised in that the sliding brake lever (4 or 5) and the disengaging pin (41 or 51) are in each case parts of a one-piece injection-moulded part. (Figures 1 - 3)
8. An adjusting drive according to claim 5 or 6, characterised by a connection of the driving arm (2.1 or 2.2) or the driving fork (3.1. or 3.2) with the worm wheel (2) or the driver member (3) in the sense of a resilient, particularly an impact-damping drive between the worm wheel (2) and the driver member (3). (Figures 1-3)
9. An adjusting drive according to one of claims 1 to 8, characterised by contact pressure means for the sliding contact of the sliding brake lever (4 or 5 or 6) on the brake surface (1.3).
10. An adjusting drive according to claim 9, characterised by sliding brake levers preformed in one piece at the same time on the driver member (3) as the contact pressure means. (Figures 1-3)
11. An adjusting drive according to claim 9, characterised by a pivotable bearing of the sliding brake levers (4 or 5) formed as discrete components in the driver member and in each case a discrete pressure spring (7 or 8) pivoted on a pin (3.5 or 3.6) of the driver member (3) as the contact pressure means. (Figure 4)
12. An adjusting drive according to claim 9, characterised by a pivotable bearing of the sliding plastics brake levers (4 or 5 or 6), formed as discrete components, in the driver member (3) and in each case pressure springs (4.2 or 5.2 or 6.2) are injection moulded in one piece on the sliding brake levers (4 or 5 or 6) or on the driver member (3) with their one end and with the other end are supported on the driver member (3) or the sliding brake levers (4 or 5 or 6). (Figures 5,7)
13. An adjusting drive according to claim 12, characterised in that the driver member (3), on the one hand, and the sliding brake lever (4 or 5 or 6) with the integrally preformed pressure spring (4.2 or 5.2 or 5.6), on the other hand, or the sliding brake lever, on the one hand, and the driver member with the integrally preformed pressure spring, on the other hand, are parts of a one-piece assembly component, able to be injected firstly into an individual injection mould separately and removed from the mould and then able to be preassembled preferably in the injection moulding die through axial assembly. (Figure 6)
14. An adjusting drive according to claim 13, characterised in that the sliding brake levers consist of a material which is more resistant to pressure in comparison with the driver member with the one-piece injected pressure spring.
15. An adjusting drive according to one of claims 1-14, characterised by a smaller concave curve of the gear housing-side brake surface (1.3) in comparison with the corresponding convex sliding surface (4.3 or 5.3 or 6.3) of the sliding brake levers (4 or 5 or 6) in the sense of a mutual angle of engagement which is smaller than the friction angle of the materials of the brake surface (1.3) and the sliding surface (4.3. or 5.3 or 6.3). (Figure 7)
16. An adjusting drive according to claim 15, characterised by a curve extension of the sliding surface (4.3 or 5.3 or 6.3) corresponding to a logarithmic spiral. (Figure 5)
17. An adjusting drive according to one of claims 1-16, characterised in that the brake surface (1.3) is provided with recesses (1.31 or 1.32) extending transversely and open to the sliding surface (4.3. or 5.3 or 6.3) of the sliding brake levers (4 or 5 or 6) as fixing aid for the sliding brake levers (4 or 5 or 6) deforming in part so as to engage to initiate a self-reinforcing self-locking position.
18. An adjusting drive according to claim 17, characterised by recesses running transversely with in each case a profile varying over the axial depth thereof with at least one larger braking profile (1.31) and a smaller running profile (1.32). (Figure 8)

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