The present application claims the priority of German patent application no. 10 2007 016 953.3 “Guide Rail Assembly and Driving Element for Motor Vehicle Window Lifters and Method for the Production Thereof” filed on 5 Apr. 2007, the content of which is expressly included herewith by way of reference for the purposes of disclosure.
The present invention relates in general to guide rail assemblies made of plastic material for motor vehicle window lifters and relates in particular to a guide rail assembly according to the preamble of claim 1, a driving element (follower) for motor vehicle window lifters and a method for the production thereof.
From the prior art are known plastic carrier plates, also referred to as assembly carriers, which after being connected to a module carrier enable a moisture-proof separation of the wet space and the dry space, a pre-assembly of door module components and door module functions, for example of door operating elements, electric window lifters, side airbag module, speakers or similar, and allow for high mechanical strength requirements with easy installation. The advantage of using plastic as a material emerges particularly in that it is possible as a result to produce the carrier plate in a simple manner by means of injection moulding.
Examples of such carrier plates are disclosed for example in DE 199 44 965 A1 by the applicant or DE 197 32 225 A1 (corresponding to U.S. Pat. No. 5,906,072), the content of which is expressly included in the present application by way of reference.
DE 10 2005 033 115 A1 (corresponding to WO 2007/006296 A1) discloses a unit carrier made of plastic material for a motor vehicle door with a guide rail moulded integrally thereon in one piece. The guide rail should be characterised by high stability and rigidity in order to resist the considerable forces arising during operation of the guide rail. The guide rail comprises two guide webs spaced apart from each other formed on each of which are guide protrusions that protrude inwards away from the respective guide web. Additional stiffening beads and concavities are provided in the region of the guide rail to increase the rigidity. Thus the guide webs are not bendable in the sense of the present application.
DE 10 2004 063 514 A1 (corresponding to WO 2006/069 559 A1) relates to a window pane made of synthetic material for motor vehicles. Disclosed is a carrier plate made from a plastic material on which a guide rail is formed integrally. To safeguard against transverse forces, the guide rail is stepped in design as illustrated in
DE 36 00 413 C2 (corresponding to U.S. Pat. No. 4,700,508) discloses a central guide rail, formed from a sheet metal profile and fixed to the motor vehicle bodywork, for a motor vehicle window lifter, wherein slide elements are disposed on the guide rail spaced apart from each other and are slidable on flanges of the guide rail which are orientated perpendicularly and parallel to the window pane.
A cost benefit emerges particularly if the guide rail, which serves to guide a driving element serving to connect the window pane to the window lifter, is also made of plastic material, is in particular integrally with the carrier plate, namely by means of injection moulding of a plastic material. In order to guide the window pane and the driving element securely in a direction at right angles to the vehicle's longitudinal direction, the driving element must engage behind the guide rail's guiding profile. Only in this way does the driving element remain securely guided on the guide rail even at comparatively high accelerations in the motor vehicle's transverse direction such as occur particularly when the door is slammed shut. As explained previously particularly on the basis of DE 10 2005 033 115 A1, comparatively large sliders are necessary in the moulding tool in order to implement such a rear grip when injection moulding the carrier plate from a plastic material. This increases the cycle time when injection moulding the carrier plate and thus also the costs and risks.
Thus it is an object of the present invention to provide a guide rail assembly made of a plastic material for motor vehicle window lifters, said assembly being inexpensive and easy to produce and install and which reliably guides a driving element. According to a further aspect of the present invention, there is also to be provides a driving element for a motor vehicle window lifter made of a plastic material, said driving element being inexpensive and easy to produce and install and being reliably guided on a guide rail, in particular on a guide rail which will be explained subsequently in greater detail. According to further aspects of the present invention, there is also to be provided a method for the production of a guide rail assembly and a driving element, as explained subsequently.
These and further objects are achieved according to the present invention by means of a guide rail assembly having the features according to claim 1, by a driving element or follower according to claim 20 and by a method for the production or assembly thereof according to claims 17, 27 and 28, respectively. Further advantageous embodiments are the subject-matter of the related dependent claims.
Thus the present invention proceeds according to a first aspect from a guide rail assembly for motor vehicle window lifters, which is formed from a plastic material and comprises a flat carrier and at least one guide rail for guiding a window lifter driving element, wherein the guide rail has two guide webs spaced apart from each other, which protrude from the carrier, and wherein guide protrusions are formed on the guide webs, each of which extends over the entire guidance length of the guide webs, and which protrude by a predetermined distance inwards or outwards from the respective guide web such that the driving element cooperating therewith is securely guided against detachment perpendicular to the carrier.
According to the invention, the guide webs are designed such that in the region of the guide protrusions they are each elastically bendable inwards or outwards by at least the predetermined distance. Thus according to the invention, the guide rail may be demoulded from an injection moulding tool by means of elastic deformation of its guide webs. Consequently, according to the invention, it is possible to reduce the number of sliders necessary for the moulding tool. In particular, no cross sliders or transversal sliders are necessary for forming the guide webs as all the moulding tool parts can be withdrawn in the same direction in order to demould the guide rail from (out of) the moulding tool.
In this case the guide protrusions protrude preferably perpendicularly or, according to further embodiments, virtually perpendicularly away from the carrier and are formed integrally therewith. The carrier may, according to a further embodiment, be extended into a carrier plate basically known from the prior art, also referred to as a door module carrier, which can also carry at least one further guide rail. At the same time, the guide rail is formed according to the invention from two guide webs spaced apart from each other, which together form a guide rail having a substantially U-shaped cross-section, wherein a guide protrusion protrudes inwards and/or outwards from the inside or outside of the guide webs, said guide protrusion cooperating positively with correspondingly formed sections of the driving element in order to guide it securely in the guide rail's longitudinal direction and to safeguard against detachment of the driving element perpendicular to the longitudinal direction, i.e. in the intended transverse direction of the vehicle. For this purpose the driving element preferably engages behind one or a plurality of the guide rail's guiding protrusions as explained below.
To implement such a rear grip, the protrusions each have, according to a further embodiment, a guide surface facing towards the carrier, which preferably represents a plane, wherein the notional extension of the guide surface includes a first acute angle with a line perpendicular to the carrier. The protrusion of the inclined guide surface onto the plane defined by the carrier in the region of the guide rail thereby defines the predetermined distance referred to previously by which the guide webs are bent elastically inwards or outwards on demoulding from the moulding tool. Sections of a moulding tool also engage, in a similar manner to the driving element, behind the guide protrusions after injection moulding of the guide rail assembly. According to the invention, demoulding of the guide rail assembly from the moulding tool is made easier in that the guide surface previously mentioned extends at an angle and not in parallel with the carrier. According to a further embodiment, however, such a rear grip can also be still be implemented in principle if the guide surface previously mentioned extends in parallel with or substantially in parallel with the carrier.
According to a further embodiment, the protrusions each also have a bevel facing away from the carrier, the notional extension o which includes a second acute angle with a line perpendicular to the carrier. In this case the first acute angle is smaller than the second acute angle. The bevel facing away from the carrier is thus formed preferably steeply in the installation (assembly) direction to enable effortless clipping or pushing of the driving element onto the guide rail. As a result, it is possible to advantageously reduce installation forces in particular. On the other hand, the guide surface facing the carrier is formed flatter in this case to enable high detachment forces of the driving element perpendicular to the carrier and thus to ensure a high holding force of the driving element on the guide webs. However, the angle must be chosen such that demoulding of the guide rail assembly from the injection mould or from the tool can be carried out without problems, particularly without damage to the guiding regions of the guide rail assembly.
The angles of inclination of the guide surface or bevel referred to previously are appropriately chosen in this case such that the limits of elastic deformability of the material regions concerned are taken into account when designing the tool and when specifying the dimensions of the portions of the guide rail. The demoulding forces arising in this case are not essential for the invention.
According to a further embodiment, the guide protrusions each have a spherical, i.e. essentially ball-shaped or outwardly convex guide surface on the side facing towards the carrier, which merges into the associated guide web at an obtuse angle. It is also possible to implement forcible demoulding of the guide rail assembly from the moulding tool with elastic deformation of the guide webs due to a spherical guide surface.
According to a further embodiment, the guide webs in the region of the guide protrusions are each bendable elastically inwards or outwards by the predetermined distance on operation of a minimum force, whereby the minimum force corresponds to a force required for demoulding of the guide rail or guide rail assembly made of plastic from the moulding tool. Expediently, the required minimum force is greater in this case than a maximum force which corresponds to a maximum holding force of the driving element on the guide rail during intended use. Such a maximum holding force may be specified here, for example, by the driving element's mass multiplied by a maximum intended transverse acceleration, i.e. acceleration in the vehicle's transverse direction. Consequently, sufficient resistance to detachment of the driving element on the guide rail is implemented even without additional securing elements which secure the driving element on the guide rail.
According to a further embodiment, the guide rail assembly referred to above comprises a window lifter driving element having contact sections, which are formed in correspondence with the guide protrusions of the guide webs and cooperate therewith in order to guide the driving element securely perpendicular to the carrier to prevent detachment. Preferably, the window lifter driving element is guided in the process substantially without play in the vehicle's longitudinal direction and secured against tilting about the guide rail's longitudinal axis.
According to a further embodiment, formed in each case on the driving element are securing means which counteract or prevent or inhibit bending of the guide webs. Here the securing means may be permanently in contact on the inner or outer sides of the guide webs or may only come into contact with them when the guide webs are bent inwards or outwards and namely by a distance that is smaller than the predetermined distance previously referred to which would lead to cancellation of the positive fit previously referred to between the driving element and the guide protrusions. At the same time the securing means have sufficient rigidity, particularly in the vehicle's longitudinal direction, to suppress or inhibit bending or further bending of the guide webs.
Expediently, the driving element has a central protrusion which protrudes into an inner side of the essentially U-shaped guiding profile of the guide rail.
The central protrusion may at the same time be thickened in a mushroom-shape in order to implement the rear grip referred to previously, in particular in order to implement a positive fit between the mushroom-shaped thickened section of the driving element and the guide protrusions of the guide webs protruding into the inner volume of the guide rails. In such an embodiment, the securing means are disposed on an outer side of the guide webs, i.e. on a side of the guide webs opposing the guide protrusions.
According to a further embodiment, the securing means are designed as resilient webs, which are bent up at an acute angle and, directed towards a base of the driving element, are inclined towards the outsides of the guide webs. In this way it is possible to implement an advantageously high intrinsic stiffness of the securing webs against outward bending of the guide rail's guide webs. Preferably, in this case the mushroom-shaped thickening on the driving element's central section protrudes further into the inside of the guide rail than the elastic securing webs stand out from the driving element's base. In this way it is possible to virtually exclude detachment of the driving element from the guide rail in the vehicle's transverse direction.
According to a further embodiment, the guide protrusions are provided on the outside of the guide web, whereby resilient securing webs protrude in the manner of wings from the outer sides of the driving element, the front free ends of said securing webs being designed to correspond with the guide protrusions and being in contact therewith. At the same time the driving element is disposed practically jammed against the guide webs of the guide rail which reliably prevents detachment of the driving element from the guide rail in the vehicle's transverse direction. Expediently, the contact surfaces are formed as concave dished webs.
For reliable introduction of the driving element into the guide rail profile referred to previously, introductory bevels are provided at the same time on the sides of the guide protrusions facing away from the carrier, said bevels coming into contact with a central protrusion of the driving element and/or with the securing means on introduction of the driving element into the guide rail and so bringing about elastic bending of the guide webs of the guide rail or of the securing means on introduction of the driving element into the guide rail profile.
According to a further aspect of the present invention, a method is provided for the production of a guide rail assembly, as described previously, by means of injection moulding from a plastic material. To form the guide rail, the moulding tool in this case comprises three movable moulding tool parts, which together form cavities for forming the flat carrier and for forming the guide webs with the guide protrusions formed integrally therewith. According to the invention, in the process the part of the moulding tool defining the guide rail's interior is designed in a wedge shape, thus its marginal surfaces run towards or away from each other at an acute angle. In this case, for forming the guide rail profile, the wedge-shaped moulding tool part is disposed between two adjacent moulding tool parts, which are expediently formed in one piece. According to the invention, these three movable moulding tool parts are withdrawn in the same direction when demoulding the guide rail assembly from the moulding tool. The moulding tool according to the invention thus manages without a cross slider (transverse slider) which conventionally leads to an increased cycle time and thus to higher costs and risks. When the wedge-shaped part of the moulding tool is withdrawn, there is elastic bending of the guide webs forming the guide rail at the same time, as described previously.
According to a further aspect of the present invention, which may also in principle be claimed separately by means of an independent claim, but which is particularly designed or suitable for a guide rail assembly, as described previously, according to the invention a driving element for motor vehicle window lifters is further provided, which has at least one U-shaped longitudinal recess and is comprised of a first material, expediently of plastic and produced in a plastic injection moulding process. According to the invention, the driving element has at least one sliding insert, which is formed from a second material that is different from the first material and which is held securely in the relevant longitudinal recess of the body. At the same time the sliding insert has a guide groove, which is formed to correspond at least in sections to a guide web of the associated guide rail such that the driving element (follower) is movably guided in the guide web's longitudinal direction by positive-fit engagement of the guide web in the guide groove and is secured against detachment perpendicular to the longitudinal direction.
The sliding insert is thus formed as a separate component from a different material such that, according to the invention, it is possible to provide a particularly appropriate tribological pairing for the counterpart, i.e. for the associated guide web.
According to a further preferred embodiment, according to the invention, a guide rail assembly is provided, which comprises a driving element (follower), wherein a longitudinal recess is formed in the driving element, which extends parallel to the carrier's guide webs, and whereby a locking web furthermore protrudes from the carrier, said locking web engaging in the longitudinal recess so as to counteract bending of the web's surfaces forming the longitudinal recess and/or to prevent the at least one sliding insert from popping out of the associated U-shaped longitudinal recess on detachment of the driving element perpendicular to a plane defined by the carrier. In this manner the locking web locks each sliding insert inserted into the driving element.
At the same time, according to the invention, it is possible to simplify the assembly of a guide rail assembly which comprises a guide rail and a driving element engaging therein. The driving elements are conventionally threaded (inserted) into the guide rail profile at the top and bottom end of the guide rail and then slid into a position determining the window lifter's assembly position. As also with the previously mentioned first aspect of the present invention, relating to the guide rail assembly in which the driving element may be pressed onto or clipped into the guide rail under elastic deformation of the guide webs in the vehicle's transverse direction, the driving element may also, according to the second aspect of the present invention, be assembled by pressing on or clipping in under the application of force in the vehicle's transverse direction. In this case, first of all the appropriate sliding insert is placed onto or slid onto the associated guide web, if necessary under elastic deformation of side walls of the U-shaped sliding insert. The driving element is subsequently pushed onto the sliding insert or sliding inserts such that each sliding insert is accommodated in the driving element's associated longitudinal recess and thus a driving element is formed which is securely guided on the guide web in its longitudinal direction but is secured on the guide web against detachment perpendicular to the longitudinal direction, i.e. in the vehicle's transverse direction.
According to a preferred alternative embodiment, the sliding inserts are, however, first inserted in the driving element, in particular clipped in, in order to thus form a pre-assembled driving element unit. This is then placed on the associated guide webs in such a manner that the driving element is movably guided on each guide web in the longitudinal direction thereof and is secured in a direction perpendicular thereto. Subsequently, the driving element is pushed into a region in which the carrier's locking webs engage in the driving element's longitudinal recess in such a manner that bending of the driving element's surfaces forming the longitudinal recess and/or popping of the at least one sliding insert out of the associated U-shaped longitudinal recess on detachment of the driving element perpendicular to a plane defined by the carrier is counteracted such that the sliding inserts are locked or secured in the driving element.
At the same time, the driving element may comprise securing means in order to hold the sliding insert securely in each longitudinal recess. Basically, such securing means may be implemented by means of a friction fit, force fit or positive fit. Especially preferred, the securing means according to the invention are implemented by means of a positive fit. This may be implemented by the engagement of securing protrusions and securing recesses formed on the driving element and the sliding insert respectively into securing recesses and securing protrusions corresponding to the sliding insert or the driving element.
According to a preferred embodiment, the securing means in this case are implemented as protruding longitudinal edges of the driving element's relevant longitudinal recess. Thus the sliding insert may be introduced therein by clipping on of the driving element.
In a further embodiment, having two sliding inserts spaced apart from each other, a central web may be formed between the sliding inserts, said web having a central longitudinal recess, which enables elastic bending of the side walls limiting the driving element's longitudinal recesses when the sliding inserts are clipped in. At the same time, securing hooks, which hold the sliding inserts securely in the longitudinal recess by means of positive fit, may be formed on the central web.
The invention will be described in the following in an exemplary manner and with reference to the associated drawings, from which will ensue further features, advantages and objects to be achieved. The figures show:
a a driving element according to a further embodiment of a guide rail assembly of the present invention, which is held securely on the carrier against detachment perpendicular to the carrier using a locking web provided on the carrier;
b in a schematic partial view from above the guide web of the guide rail assembly according to
a in a partial section and in a view from above the cooperation of the driving element and the locking web of the guide rail assembly according to
b in a partial section and in a view from above the cooperation of the driving element and the locking web of the guide rail assembly according to
Identical reference numerals in the Figures indicate identical elements or element groups or those with substantially the same effect.
According to
As will be described subsequently with reference to
According to
In the embodiment according to
A method for injection moulding of the carrier plate with the guide rail according to
The following procedure is followed to produce the carrier plate with the guide rail: first of all the moulding tool is formed according to
In a subsequent step, as shown in
As can be seen from
A third embodiment is described below with reference to
The following procedure is followed to demould such a guide rail: first of all wedge-shaped moulding tool part 32 is withdrawn in the wedge direction illustrated such that the insides of guide webs 4 are exposed. Subsequently, adjacent moulding tool parts 30, 31 are withdrawn in the same direction as indicated by the arrows. In the process, introductory bevels 7 of guide protrusions 5 slide off on the narrowed sections of moulding tool parts 30, 31 which leads to elastic bending of guide webs 4 in the inward direction. Finally, guide webs 4 return to their unstressed initial position 4 according to
To further secure driving element 10 on the rail profile, provided laterally on driving element 10 are marginal webs 19, 17, whereby lateral webs 19 extend substantially perpendicular to the base of driving element 10 and securing webs 17 face towards guide protrusions 5 at an acute angle. According to
The following procedure is followed for assembly of such a guide rail assembly: first of all a guide rail is provided, for example with two guide webs 4 spaced apart from one another, as illustrated in
a shows a variation of the guide rail assembly according to
To be able to assemble the driving element illustrated on guide webs 4 of a carrier 1 provided with locking web 260, said locking web 260 according to
It is possible to dispense with the narrowed section or cut-out 261 previously referred to if the geometry of the module carrier allows the driving element to be pushed on in the adjustment direction of driving element 10. The advantage of locking web 260 is therefore, that unintentional bending upwards of securing hooks 25 and thus unbuttoning of protrusions 5 from slider insert 27 can be securely prevented. Of course, for this it is necessary for the outer regions of the driving element or the body of the driving element as such to be designed with sufficient rigidity.
As will clearly be self-explanatory to the person skilled in the art on studying the preceding description, the features of the embodiments described previously may also be combined with each other in any other way than previously described.
1 Carrier plate
2 Base of guide rail
3 Inside of guide rail
4 Guide web
5 Guide protrusion
6 Introductory bevel
7 Bevel
8 Front face of guide web 4
9 Rounded contact section/guiding section
10 Driving element
11 Central thickened section
12 Narrowing
13 Front face of the central thickened section 11
14 Front bevel
15 Rear bevel
16 Inclined marginal web
17 Securing web
18 Edge
19 Marginal web
20 Securing element
21 Rounded securing section
22 Stiffening rib
23 Bevel
24 Front end
25 Securing hook
26 Recess
260 Locking web
261 Cut-out/narrowed end of locking web 260
27 Sliding insert
28 Inner leg
29 Outer leg
30 First half of moulding tool
31 Second half of moulding tool
32 Wedge insert of moulding tool
33 Central cavity
34 Cavity
35 Narrowing
36 Lateral surface of first half of moulding tool
37 Lateral surface of wedge insert 32
38 Notch
Number | Date | Country | Kind |
---|---|---|---|
102007016953.3 | Apr 2007 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2008/002610 | 3/31/2008 | WO | 00 | 1/11/2010 |