DE102008001590A1 - Welding process, housing for a drive device and drive device - Google Patents

Abstract

The invention relates to a method for fixing a pressure compensation membrane (3) to a carrier (1), in particular to a carrier (1) formed by a housing (13) of a drive device in a motor vehicle or to a carrier which can be fixed to such a housing (13) (1). According to the invention, it is provided that the pressure compensation membrane (3) is welded to the carrier (1) by thermal contact welding. Furthermore, the invention relates to a housing (13) for a drive device and a drive device.

Description

State of the art

The The invention relates to a method for welding a Pressure compensation membrane with a carrier according to the Preamble of claim 1, a housing for a Drive device according to the preamble of Claim 11 and a drive device according to claim 13th

Pressure compensation diaphragm have the task of air exchange between the housing interior and the environment allow for an impermissible overpressure or an impermissible negative pressure in the housing to prevent by temperature fluctuations. At the same time prevents the Pressure compensation membrane penetration of liquid media, such as water, in the housing of the drive device.

From the DE 196 35 180 A1 It is known to ultrasonically weld a pressure compensating diaphragm to the periphery of an opening of a carrier formed by a drive device housing. The disadvantage here is that it may come to a detachment of the pressure compensation membrane during operation, whereby moisture can penetrate into the housing of the drive device.

From the DE 10 2005 021 950 it is known to clamp the pressure compensation membrane between two housing parts. The disadvantage here is the complex installation and the complex housing structure. In addition, the pressure compensation membrane can slip when not exactly positioning.

Disclosure of the invention

Technical task

Of the Invention is based on the object, a simple, optimized To propose a method for fixing a pressure compensating membrane to a carrier, a permanent, stable connection between the pressure compensation membrane and the carrier guaranteed. Furthermore, the object is to a correspondingly optimized housing for a drive device to propose, in which a secure hold of the pressure compensation membrane is secured to a carrier. Furthermore, there is the Task therein, a correspondingly optimized drive device propose.

Technical solution

These Task is in terms of the method with the features of the claim 1, in terms of the housing with the features of the claim 11 and with regard to the drive device with the features of Claim 13 solved. Advantageous developments of the invention are given in the subclaims. In the context of Invention fall all combinations of at least two in the description, the claims and / or the figures disclosed features. To avoid repetition Device also disclosed as features according to the method disclosed apply and claimable be. Likewise, according to the method disclosed Features as disclosed by the device apply and claimable.

Of the The invention is based on the idea of the pressure compensation membrane, preferably exclusively, by thermal contact welding to connect with the carrier. It lies within the scope of Invention that the support for the pressure compensation membrane directly from the housing or a housing wall the drive device or of a on such a housing or a housing wall fixable, separate carrier is formed. The membrane is preferably arranged such that they are on the circumference of a carrier and / or in the housing provided opening with the carrier thermo-contact welded becomes. Through the use of thermal contact welding is in a simple and cost-effective way, a permanent, stable connection between the pressure compensation membrane and the carrier achieved by themselves occurring during operation of a drive device Vibrations will not be solved. Through the thermal contact welding, So by pressing the pressure compensation membrane to the carrier By means of a heated tool is doing a form and / or material connection between the pressure compensation membrane and the carrier realized without a comparatively expensive Ultrasonic welding device or laser welding device to have to provide.

From particular advantage is an embodiment of the method, when the thermal contact welding not single-stage, but at least two stages, d. H. with two, preferably one after the other performed, welding steps performed becomes. This makes it possible, a particularly stable Connection between the pressure compensation membrane and the carrier to realize because of the viscous carrier material even deeper into the structure at the second welding step, preferably incorporate a network structure of the pressure compensation membrane can, causing the material and / or positive connection clearly compared to only one welding step is reinforced.

In the case of thermal contact welding, the procedure is preferably such that the pressure compensation membrane is pressed against the carrier in a first welding step with an embossing punch is, wherein the contact surface of the stamping die is heated to the pressure compensating diaphragm to a first temperature. For welding the pressure compensation membrane while the tempered to the first temperature die is pressed with a defined force, preferably directly, on the pressure compensation membrane, such that these travels a defined way in a defined time in the direction of the wearer. After the first welding step, at least one second welding step is carried out, in which the pressure compensation membrane is again pressed against the carrier with a heated die, wherein the contact surface of the die is also tempered in this second welding step separate from the first welding step. Due to the repeated "welding embossing" or the repeated thermal contact welding, an even more intimate connection between the pressure compensation membrane and the carrier, preferably at the periphery of an opening provided in the carrier, is realized. In particular, when the pressure compensation membrane has a kind of network structure, carrier material can penetrate deeper into this network structure in the further welding step. It is possible to carry out more than two thermal contact welding steps, with time reasons for manufacturing only a two-stage thermal contact welding is preferred.

From particular advantage is an embodiment of the method, at which the contact surface temperatures of the dies at least two separate Verschweißschritten, preferably in all welding steps, differ. In the realization of two, preferably in immediate succession To be performed, welding steps is one Embodiment of the method preferred in which the first Temperature higher at the first welding step is selected as the second temperature in the second welding step. Especially it is preferred if the first temperature, preferably is significantly higher than the melting temperature of the carrier material, to allow liquefaction of the carrier material. Especially when the material of the polybutylene terephthalate support (PBT) is a contact surface temperature of the die of over 220 ° to prefer. The should Temperature, however, only be chosen so high that a previous damage the pressure compensation membrane is avoided. Preferred is an embodiment, in the pressure compensating membrane made of woven polytetrafluoroethylene (PTFE) exists.

Around an optimized strength of the connection of pressure compensation membrane and support is one embodiment in which the second temperature of the second welding step, which is preferably lower than the first temperature of the first Welding step, only slightly higher is the melting temperature of the carrier material, ie in the case of PBT, preferably from a temperature range between about 221 ° C and 230 ° C, is selected.

It is possible, the at least two welding steps with the same die in succession. However, an embodiment of the method is preferred in which the at least two welding steps with separate Embossing stamping is done to the separate embossing stamp to be able to temper permanently differently. there It is possible, identically formed dies for the at least two welding steps. However, an embodiment is particularly preferred the die for the separate Verschweißschritte different contact surface geometries and / or contact surface structures exhibit. So it is possible, for example, the first Welding step with an embossing stamp with a smooth contact surface and the second welding step to perform with an embossing stamp with a structured contact surface.

From particular advantage is an embodiment in which the Contact surface of at least one embossing stamp annular is formed, wherein the annular shape preferably to the peripheral contour of Pressure compensation diaphragm is adjusted, so in the case of a circular Contour of the pressure compensation membrane is also circular. At a at least approximately oval contour of the pressure compensation membrane the contact surface is preferably also at least approximately oval contoured.

It It was observed that the pressure compensation membrane at the first Welding step edge bulge and thus a catch basin for liquids, for example Water, can form. Since such a catch basin the function of Could affect pressure compensation membrane, an embodiment is preferred in which the bulge in the second welding step, at least largely, is undone, thereby simultaneously a possible, caused by the bulging, Connection weakening avoided or reversed is done. The bulge of the pressure compensation membrane In particular, with an adapted structure and / or contour of the Contact surface of the embossing stamp, at least partially, preferably even completely, be canceled, thereby the pressure compensation membrane after the second welding step at least approximately flat again on the, in particular crowned, Carrier is present.

The invention also leads to a housing for a drive device, preferably a housing for an adjustment drive, in particular a Window adjustment drive, in a motor vehicle. The housing in this case comprises a pressure compensation membrane, which is welded to a support of the housing, wherein the carrier is formed for example by a, in particular crowned, housing wall or by a separate, fixable to the housing, support member. The pressure compensating diaphragm is mounted to close a housing opening. According to the invention, it is provided that the pressure compensation membrane is welded to the carrier by a, in particular multi-stage, thermal contact welding. In this case, the pressure compensation membrane preferably lies flat outside the opening on the carrier, in particular without forming a peripheral collecting basin for fluids. Particularly preferred is an embodiment in which the housing is formed of plastic. The pressure compensation membrane material is preferably PTFE and / or the carrier material, in particular the housing material, PBT or other thermoplastics.

About that In addition, the invention leads to a drive device with a previously described, optimized housing, at the pressure compensation membrane by a, in particular multi-stage thermal contact welding connected to a carrier.

Brief description of the drawings

Further Advantages, features and details of the invention will become apparent the following description of preferred embodiments as well as from the drawings. These show in:

1 : a first welding step of a multi-stage thermal contact welding method,

2 a second welding step of the thermal contact welding method and

3 FIG. 2: a detail of a housing of a drive device with a pressure compensating membrane thermocontact welded to the housing. FIG.

embodiments the invention

In The figures are the same components and components with the same Function marked with the same reference numerals.

In 1 is a carrier 1 shown from PBT. The carrier 1 is formed by a housing portion of a drive device housing. As it turned out 1 further indicates the carrier 1 a crowned raised section 2 on, with which a pressure compensation membrane 3 , in this embodiment of woven PTFE, to be welded. The pressure compensation membrane 3 is gas-permeable and liquid-tight and has in the embodiment shown a circular peripheral contour.

In the carrier 1 is an opening 4 provided centrally within the crowned portion 2 is arranged. The pressure compensation membrane 3 is arranged so that it the opening 4 closes, leaving through the opening 4 and the pressure compensation membrane 3 through an exchange of air between the interior of the housing and the environment is possible, wherein an entry of liquids into the housing interior, in which an electric motor and / or, in particular designed as a worm gear, transmission is prevented.

For welding the pressure compensation membrane 3 with the crowned section 2 of the carrier 1 , more precisely with a spherical circumference 5 the opening 4 , the pressure compensation diaphragm becomes 3 first on the crowned raised section 2 of the carrier 1 hung up. Then, with the help of a first stamping die 6 a joining force F in the direction of the carrier 1 to the pressure compensation membrane 3 exercised. As it turned out 1 results, is the first die 6 sleeve-shaped and has a central opening 7 on whose inner diameter is slightly larger than the inner diameter of the opening 4 in the carrier 1 , The stamp 6 indicates on its the pressure compensation membrane 3 facing end face an annular in this embodiment contact surface 8th on, whose outer diameter is slightly smaller than the outer diameter of the pressure compensating diaphragm 3 , The contact surface 8th is heated, for example, with an integral, not shown, resistance heating to a first temperature of 250 ° C in this embodiment, so that the carrier 1 in the scope of the scope 5 melted and the molten material in the woven PTFE material of the pressure compensation membrane 3 penetrate and form-fitting can connect with this. During the welding embossing process, the pressure compensation membrane becomes 3 by the defined application of the joining force F over a defined distance and in a defined period of time in the direction of the carrier 1 adjusted in.

After the first welding step, the first die becomes 6 removed and, preferably after the carrier material has solidified again, a second welding step with a second, separate die 9 carried out.

As it turned out 2 results, is the pressure compensation membrane 3 after the first, based on 1 explained, welding step arched on the edge, so that an annular catch basin 10 is formed for liquids. The second, below 2 explained, welding step is preferably designed such that the catch basin 10 disappears, so the pressure compensation membrane 3 on the edge immediately on the carrier 1 rests. This can be realized, for example, that the second die 9 a contact surface 11 having a larger radial extent than that in FIG 2 is shown. The radial extent of the contact surface is preferred 11 of the second embossing stamp 9 larger than the radial extent of the contact surface 8th of the first stamp 6 , The contact surface 11 of the second embossing stamp 9 is how the contact surface 8th of the first stamp 6 , contoured circular. This is in the embodiment shown by the choice of a sleeve-shaped second stamping die 9 reached, which has a centric opening 12 has, whose diameter is greater than the diameter of the central opening 7 of the first stamp 6 , For the second welding step, the contact surface 11 , preferably with an integral, not shown, resistance heating to a second temperature which, although greater than the melting temperature of the carrier 1 but less than the first temperature of the contact surface 8th of the first stamp 6 at the first welding step. The thus heated second die 9 becomes with a joining force F in the direction of the carrier 1 pressed, wherein the joining force F of the second embossing step in the embodiment shown is greater than the joining force F of the first welding step. In the second welding step, an even deeper penetration of viscous carrier material into the net-like structure of the pressure compensation membrane 3 achieved. The second welding step is carried out for a defined time, in which the pressure compensation membrane 3 a defined path towards the carrier 1 into it.

In 3 is a section of a case 13 an adjustment of a motor vehicle shown. Evident is an approximately oval pressure compensation membrane 3 , the edge by a multi-stage thermal contact welding process with a directly from the housing 13 formed carrier was welded. It can be seen that the pressure compensation membrane 3 not bulging edge, but just on the case 13 or the carrier 1 rests.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19635180 A1 [0003]
• - DE 102005021950 [0004]

Claims (13)

Method for defining a pressure compensation membrane ( 3 ) on a support ( 1 ), in particular on one of a housing ( 13 ) carrier of a drive device in a motor vehicle ( 1 ) or on one of such a housing ( 13 ) definable carrier ( 1 ), characterized in that the pressure compensation membrane ( 3 ) by thermal contact welding with the carrier ( 1 ) is welded. Method according to claim 1, characterized in that Thermal contact welding is multi-stage becomes. Method according to one of claims 1 or 2, characterized in that the pressure compensation membrane ( 3 ) in a first welding step with an embossing stamp tempered to a first temperature ( 6 . 9 ) against the carrier ( 1 ) is pressed. Method according to claim 3, characterized in that the pressure compensation membrane ( 3 ) after the first welding step in a second welding step with a stamping die tempered to a second temperature ( 6 . 9 ) again against the wearer ( 1 ) is pressed. Method according to claim 4, characterized in that that the first temperature is higher than the second temperature. Method according to one of claims 4 or 5, characterized in that the first temperature higher is chosen as the melting temperature of the carrier material, preferably higher than 220 ° C at PBT. Method according to one of claims 4 to 6, characterized in that the second temperature only slightly is higher than the melting temperature of the carrier material. Method according to one of claims 4 to 7, characterized in that for the first and the second welding step separate, preferably different, contact surface geometries and / or contact surface structures having embossing dies ( 6 . 9 ) are used. Method according to one of claims 4 to 8, characterized in that the at least one embossing stamp or at least one of the embossing stamps ( 6 . 9 ) an annular contact surface ( 11 ) having. Method according to one of claims 4 to 9, characterized in that an occurring at the first welding step edge bulge of the pressure compensation membrane ( 3 ) is smoothed, at least substantially, with the second welding step. Housing for a drive device, in particular for an adjustment drive in a motor vehicle, with one with a support ( 1 ) welded, a housing opening spanning pressure compensation membrane ( 3 ), characterized in that the pressure compensation membrane ( 3 ) by a, in particular multi-stage, thermal contact welding with the carrier ( 1 ) is welded. Housing according to claim 11, characterized in that the carrier ( 1 ) is a housing section or on the housing ( 13 ). Drive device, in particular adjusting drive in a motor vehicle, with a housing ( 13 ) according to one of claims 11 or 12.