DE102005012685A1 - Method of making continuous sealing profile for automobile use, includes main section extruded in one material and additional integral section extruded in second material - Google Patents

Abstract

The main section (20) is extruded using a first material and the integral additional section (30a, 30b) is extruded from a second material. Coefficients of thermal expansion of the two materials differ. The additional section is extruded to a predetermined length and/or varying cross section in the longitudinal direction. This variation takes place continuously. The main section comprises both a holding section (21) and a sealing section (26), which are bonded together by the extrusion process. An independent claim is included for the corresponding seal.

Description

The Invention relates to a method for producing a sealing strand, especially for one Motor vehicle extending in a longitudinal direction and a Basic section and at least partially an additional section having. The sealing strip is extruded such that the additional section by variable extrusion cohesively with the base section is connected. The invention further relates to one in this way produced sealing strip.

One Such sealing strip is used in motor vehicles, for example for sealing in the area of a tailgate for use. The sealing strand usually indicates a holding section for fixing the sealing strand to the Body on. An elastic connected to the holding section deformable sealing portion, for example in the form of a hollow chamber profile, lies in the closed position of the tailgate on the tailgate and guaranteed so the sealing of the tailgate. In a corresponding manner, the sealing strip allows also the sealing of a vehicle door.

The Production of such a sealing strand takes place in an extrusion process. In this case, the cross-sectional shape determining outlet cross section the nozzle an extruder during the extrusion changed in predetermined areas. So can the cross section the extruded strand profile in the longitudinal direction made variable become. This procedure is referred to by the term "variable extrusion", on which the present invention makes reference to.

A method for producing an extruded U-shaped strip for a gasket of a motor vehicle is disclosed in U.S. Patent No. 5,343,841 EP 0 955 148 B1 described. The known method provides to introduce a high temperature thread into the molding compound during extrusion in order to change the neutral bending axis of the strip.

Furthermore, the describes EP 0 081 093 B1 an extruder for producing a profiled strand of an elastomeric material, in particular for edge trim strips of motor vehicle windows. The extruder has an extrusion die, the outlet opening is temporarily concealed by means of a panel. The panel is either rectilinearly movable or arranged on a circular path pivotally in front of the extrusion die. In this way, the cross section of the extruded profile strand can be made different over the length thereof.

Furthermore, from the DE 202 16 759 U1 a sealing strip for sealing between a movable vehicle part and the body of a motor vehicle known. A section of the sealing strip is designed as a hollow chamber profile. In a region of high curvature, the sealing strand is reinforced. The reinforcement is intended to prevent or limit a collapse of the sealing area. The production of the sealing strand is carried out by means of variable extrusion. Here, the extrusion gap of the extruder is controlled during the extrusion process so that the reinforcement occurs in certain sections in the longitudinal direction of the sealing strip. As a result, the sealing strip can be extruded in one work step.

When it is disadvantageous in the known production methods for such sealant tapes proved that after making the seal as a further step a shaping of the sealing strip to adapt the shape of the Sealing strands to the shape of the components between which the gasket is arranged is required. Especially with seals of Doors or Tailgates of motor vehicles is a partly highly curved shape required. So far, the shaping by means of heating the Sealing strands and subsequent bending into the desired shape takes place, so that the seal after the final cooling the desired Course has. This procedure is very time consuming because as further steps after the extrusion heating, bending and cooling required are.

It is also known, the shaping of a sealing strand by subsequent Cropping the sealing strand to influence. Here arise However, a high material consumption and thus high production costs. Further falls by cutting a large amount of waste material, the a heavy burden for the environment means.

Of the Invention is based on the object, a process for the preparation to create a sealing strand with which a simple and variable shaping of the sealing strip can be achieved. Moreover should such a sealing strip be specified.

To solve this problem, in a method for producing a sealing strip, in particular for a motor vehicle, provided with the features mentioned in accordance with claim 1 according to the invention that the base portion of a first material and the additional portion of a second material is extruded, wherein the second material another thermal expansion coefficient than the first material.

The invention Method is based on the knowledge during the extrusion of the base section from a first material in sections, a variable parallel Perform coextrusion of the additional portion of a second material. Of the targeted use of materials with different thermal Extension for the basic section and the additional section enable a different one Shrinkage behavior of the base section and the additional section on cooling of the sealing strand. As a result of this behavior can be Control the shape of the sealing strip during the cooling process. Furthermore, the different cooling behavior causes a shift the neutral fiber of the sealing strand. The sealing strand can be imposed on a predetermined shape.

The thermal expansion coefficient of the first and second material can in a certain ratio to stand by each other. Furthermore can the first material and the second material in another Material properties differ, leading to a different deformation of the additional section compared to the base section leads. Further may be the second material during The extrusion is admixed with a substance that cools the Additional section accelerates or slows down.

Farther creates this targeted use of variable extrusion for education the additional section a sectional additional material order, whereby a shift of the center of gravity of the corresponding cross-sectional area in comparison to a section with a different cross-sectional area of the Additional section or compared to a section without additional section results. So it can be a targeted change in the location of the neutral Fiber of the sealing strand can be achieved.

With the inventive Method it is thus possible the position of the neutral fiber on the one hand by the additional Material order by means of the additional section and on the other hand by the different cooling behavior due to the use of different materials for the base section and to change the additional section. The sealing strip can thus at predetermined locations accordingly the respective geometric conditions at the installation of the sealing strand to be formed, which makes the later Installation is facilitated.

advantageous Embodiments of the inventive method are in the Claims 2 to 13 described.

In Development of the inventive method It is proposed that the additional section be on a predetermined Length in longitudinal direction is extruded. This predetermined section is usually in the area of unsteady body contours and especially in the area of curvature changes.

at an advantageous development of the method is provided that the additional portion having a longitudinally varying cross-section is extruded. It is particularly useful when the cross section the additional section in the longitudinal direction constantly changing. That way you can the sealing strand is given a continuously changing curvature and jump-like changes of the cross section can be prevented.

A further advantageous embodiment of the method is in that the base section has a holding section and a sealing section, wherein the holding portion and the sealing portion by the extrusion cohesively be connected to each other. So the holding section on his Function for fastening the sealing strip to a rigid Component of the body and the sealing portion on its sealing function be coordinated, for example, by the design of the wall thicknesses and the use of different soft materials.

From It is also advantageous if the holding portion with a U-shaped cross section provided and therefore with a first leg, a second Leg and a base portion is extruded, wherein the base portion connects the first leg with the second leg. Such U-shaped Training the holding section is particularly suitable for the Attaching the sealing strip to a flange or frame the body of the motor vehicle. The fixation can, for example simply by putting the holding section on the flange respectively.

In an advantageous development of the method it is provided that the first leg and / or the second leg is provided with the additional portion. In particular, in the attachment of the additional portion on an outer side of the respective leg thereby deformation can be generated in the direction of the side on which the additional portion is arranged. Furthermore, the base portion and / or the sealing portion may be provided with the additional portion. In this way, the sealing strand or only a portion thereof, such as the holding portion or the sealing portion, in each bent desired direction and so the desired shape of the sealing strip are generated.

Around a reliable one To ensure the hold of the holding section It is advantageous if the holding section with at least one Haltelippe is provided. Preferably, the retaining lip over the entire Length of the Sealing extruded in such a way that the retaining lip cohesively with is connected to the holding section. Preferably, the first leg and the second leg on its inner sides with at least one retaining lip provided so that they engage with a rigid component can.

in the In view of the preferred use of the sealing strip for sealing a door or a tailgate of a motor vehicle, it is expedient to Sealing portion with at least one hollow chamber and / or a Sealing lip to extrude. The wall thickness of the sealing section can meet the requirements for elastic compressibility be adjusted. In the formation of the sealing portion in Form of a hollow chamber can be used to stabilize the hollow chamber wall a sectionwise reinforcement, for example, in the form of a web attached to the wall is and in the direction of the hollow chamber interior shows, are provided. Thereby, a collapse of the hollow chamber can be prevented.

Conveniently, The retaining portion and / or the sealing portion of the first Material extruded. To guarantee A practice-oriented extrusion process is the first material or the second material is an elastomer, preferably ethylene-propylene-diene rubber (EPDM), a thermoplastic elastomer (TPE), or a vulcanized thermoplastic Elastomer (TPV).

moreover becomes the solution the above task in accordance with claim 14 proposed a sealing strip, in particular at a motor vehicle application finds. Which is in a longitudinal direction extending sealing strip has a base portion and at least in sections, an additional section, wherein the additional section by variable extrusion cohesively with the base section connected is. In addition, the basic section consists of a first Material and the additional portion of a second material, wherein the second material has a different thermal expansion coefficient has as the first material.

One Such formed sealing strip makes the benefits of the inventive Exploiting the process. Thus, the sealing strip as a result of the targeted Use of different materials for the additional section and the basic section and as a result of the additional Material orders in the form of the additional section a predetermined Course in the longitudinal direction on. Such a material selection and the sectional design the cross-sectional shape of the sealing strip makes it possible for the sealing strip to give a curved shape in predetermined sections, without that is disturbing Tensions in the curved Sections reveal the life of the sealing strip could reduce. Further let yourself prevent wrinkling.

advantageous Embodiments of the inventive sealing strand are in the claims 15 to 26 described.

Corresponding the above statements to the inventive Method, it proves to be advantageous if the additional section on a predetermined length longitudinal extends. Preferably, the additional section has a in the longitudinal direction changing Cross-section on. To simplify the extrusion process and to jump Changes in cross section To prevent, it is advantageous if the cross section of the sealing strip constantly changing.

preferably, the base section has a holding section and a sealing section, wherein the holding portion and the sealing portion by the extrusion cohesively connected to each other. It is particularly appropriate if the holding section is a U-shaped Cross-section with a first leg, a second leg and a Ba sisabschnitt, wherein the base portion of the first Leg connects to the second leg. In an advantageous development is the first leg and / or the second leg with the additional section Mistake. In particular, it is advantageous if the additional section on an outside of the first leg or the second leg is attached. So can a deformation towards that Outside are generated, on which arranged the additional portion is. Furthermore, also the base portion and / or the sealing portion be provided with the additional section.

to Creating a simple mounting option, the holding section at least one retaining lip. This can be made of the same material as the holding section or made of a different material, being the flexibility the retaining lip over whose softness and material thickness is controlled. With regard the sealing function of the sealing strip has the sealing section preferably at least one hollow chamber or a sealing lip.

Conveniently, the holding section and / or the sealing section consists of the first Material. in principle is an elastomer as the first material or as the second material, preferably ethylene-propylene-diene rubber (EPDM), a thermoplastic elastomer (TPE), or a vulcanized thermoplastic Elastomer (TPV) used.

following The invention will be further explained with reference to the drawings. Show schematically:

1 a perspective view of the inventive sealing strip as a sealing element for a tailgate of a motor vehicle;

2 a cross section according to the line II-II through the sealing strip according to 1 in a first embodiment;

3 a cross section according to the line III-III through the sealing strip according to 1 ;

4 a cross section according to the line IV-IV through the sealing strip according to 1 and

5 a cross section along the line II-II through the sealing strip according to 1 in a second embodiment.

1 shows schematically the three-dimensional course of a sealing strand 10 in the form of a closed ring as a sealing element for the tailgate of a motor vehicle. The sealing strand 10 extends in a course of the sealing strand 10 corresponding longitudinal direction. The 2 to 5 show the in 1 indicated cross sections through the sealing strip 10 in the area of strong bends.

The sealing strand 10 has over its entire length in the longitudinal direction of a base section 20 of a first material and having a substantially constant cross-section. The basic section 20 is in a holding section 21 and a sealing portion 26 divided. The one by a metal carrier 28 armored holding section 21 has a substantially U-shaped cross-section and is provided with a first leg 22 , a second leg 23 and one the thighs 22 . 23 connecting base section 24 Mistake. At each of the thighs 22 . 23 are two longitudinally over the entire length of the sealing strand 10 running retaining lips 25 for fastening the sealing strip 10 arranged on a frame of the body of the motor vehicle. In the area of the base section 24 is the sealing section 26 by the extrusion process cohesively with the holding section 21 connected. The sealing section 26 has a hollow chamber 27 on, causing the sealing section 26 a certain flexibility is given. The hollow chamber 27 is closed at closed ner position of the tailgate at least partially and obtained after opening the tailgate back to the original shape 2 . 3 . 4 or 5 ,

As if from a synopsis of 1 to 4 can be seen, the sealing strip 10 in each case a first additional section in the curved areas 30a and a second additional section 30b on. Depending on the particular application, it may be sufficient if only one additional section 30a exists as if from 5 is apparent. The or the additional sections 30a . 30b are made of a second material, which is at least with regard to its shrinkage behavior during cooling of the shrinkage behavior of the first material from which the base portion 20 exists, as far as different, that a bend of the sealing strand 10 is achieved in the desired direction and a displacement of the neutral fiber compared to an adjacent cross-section. The different shrinkage behavior causes a bending of the sealing strip 10 each in the direction of the page, on which the one or more additional sections 30a . 30b are attached. The or the additional sections 30a . 30b be during the extrusion of the base section 20 shaped in sections and with a certain length in the longitudinal direction by variable extrusion and so cohesively with the base section 20 connected. In this case, each of the in the 2 to 5 shown additional sections 30a . 30b a continuously changing cross section in the longitudinal direction, so that the respective transition between a region of the sealing strand 10 without additional section 30a . 30b and an area with additional section 30a . 30b flows smoothly.

As continues from the 2 to 5 As can be seen, the additional sections 30a . 30b either on the holding section 21 as well as on the sealing section 26 (please refer 2 and 3 ) or only on the holding section 21 (please refer 4 and 5 ) arranged. In detail are in the in 2 shown cross cut the additional sections 30a . 30b in the transition region of the sealing section 26 to the base section 24 positioned so that the first additional section 30a in the hollow chamber 27 at the sealing portion 26 as well as at the base section 24 and the second additional section 30b on the outside of the second leg 23 as well as on the outside of the sealing section 26 is arranged. This positioning of the additional sections 30a . 30b results in a displacement of the vertically oriented neutral fiber from one layer centered between the thighs 22 . 23 towards the second leg 23 , In addition, the sealing strip 10 due to the faster cooling of the additional sections 30a . 30b bent to the right, as from the consideration of the areas before and after the line II-II in 1 becomes apparent.

In a similar way it behaves in the in 3 cross section shown. Here are the additional sections 30a . 30b in the transition region of the sealing section 26 to the base section 24 positioned. The first additional section 30a is in the hollow chamber 27 at the sealing portion 26 as well as at the base section 24 and the second additional section 30b on the outside of the first leg 22 as well as on the outside of the sealing section 26 arranged. This results in a displacement of the vertically oriented neutral fiber from a position midway between the legs 22 . 23 towards the first thigh 22 , The sealing strand 10 is due to the faster cooling of the additional sections 30a . 30b bent to the left as viewed from the areas before and after the line III-III in 1 becomes apparent.

In 4 is the first additional section 30a in the lower part of the first leg 22 and the second additional section 30b in the lower part of the second leg 23 arranged. The position of the horizontal neutral fiber is shifted downwards. The sealing strand 10 is accordingly bent downwards.

According to the requirements of the desired course of the sealing strand 10 can the additional sections 30a . 30b also over the entire height of the thighs 22 . 23 to the sealing section 26 extend. Furthermore, it is possible that the additional section 30a . 30b only on the sealing section 26 is appropriate. Basically, the location, shape and material thickness of the additional section results 30a . 30b from the desired direction and strength of deformation of the sealing strip 10 ,

In the production of the inventive sealing strand 10 is the selection of the first material for the basic section 20 and the second material for the additional section 30a . 30b , the positioning of the additional section 30a . 30b at the base section 20 and the course of the additional section 30a . 30b in the longitudinal direction and in the transverse direction so set and coordinated that a predetermined position of the neutral fiber and a predetermined deformation of the sealing strand 10 is achieved.

The described embodiment of the sealing strand 10 is characterized by a simple mounting on a frame of a body of a motor vehicle. This is due to the variable shape of the sealing strip, which by the use of the first and second material with different thermal expansion coefficients and the displacement of the neutral fiber due to the additional material application in the form of the additional section 30a . 30b is justified. Thus, already during the extrusion process, the shape of the sealing strand 10 to be controlled. Subsequent heating and bending or cutting of the sealing strip 10 can be omitted. A targeted bending of the sealing strand 10 and thereby an adaptation of the sealing strand 10 a curved course is ensured.

10

sealing strip

20

base portion

21

holding section

22

first leg

23

second leg

24

base section

25

retaining lip

26

sealing section

27

hollow

28

carrier

30a

first additional section

30b

second additional section

Claims (26)

Method for producing a sealing strip ( 10 ), in particular for a motor vehicle, in which the sealing strip ( 10 ) extending in a longitudinal direction and a base portion ( 20 ) and at least in sections an additional section ( 30a . 30b ) is extruded in such a way that the additional section ( 30a . 30b ) by means of variable extrusion cohesively with the base section ( 20 ), characterized in that the basic section ( 20 ) of a first material and the additional section ( 30a . 30b ) is extruded from a second material, wherein the second material has a different thermal expansion coefficient than the first material. Method according to claim 1, characterized in that the additional section ( 30a . 30b ) is extruded in a longitudinal direction at a predetermined length. Method according to claim 1 or 2, characterized in that the additional section ( 30a . 30b ) is extruded with a longitudinally varying cross-section. A method according to claim 3, characterized in that the cross section of the Zusatzab cut ( 30a . 30b ) continuously changed in the longitudinal direction. Method according to one of claims 1 to 4, characterized in that the basic section ( 20 ) a holding section ( 21 ) and a sealing section ( 26 ), wherein the holding section ( 21 ) and the sealing section ( 26 ) are connected by the extrusion cohesively with each other. Method according to claim 5, characterized in that the holding section ( 21 ) is extruded with a U-shaped cross section, wherein the holding portion ( 21 ) with a first leg ( 22 ), a second leg ( 23 ) and a base section ( 24 ), the first leg ( 22 ) with the second leg ( 23 ) connects. Method according to claim 6, characterized in that the first leg ( 22 ) or the second leg ( 23 ) with the additional section ( 30a . 30b ). Method according to claim 6 or 7, characterized in that the base section ( 24 ) with the additional section ( 30a . 30b ). Method according to one of claims 5 to 8, characterized in that the sealing portion ( 26 ) with the additional section ( 30a . 30b ). Method according to one of claims 5 to 9, characterized in that the holding section ( 21 ) with at least one retaining lip ( 25 ). Method according to one of claims 5 to 10, characterized in that the sealing portion ( 26 ) with at least one hollow chamber ( 27 ) or a sealing lip is extruded. Method according to one of claims 5 to 11, characterized in that the holding section ( 21 ) or the sealing section ( 26 ) is extruded from the first material. Method according to one of claims 1 to 12, characterized that the first material or the second material is an elastomer, preferably ethylene-propylene-diene rubber (EPDM), a thermoplastic Elastomer (TPE) or a vulcanized thermoplastic elastomer (TPV), is. Sealing strip, in particular for a motor vehicle, which extends in a longitudinal direction and a base section ( 20 ) and at least in sections an additional section ( 30a . 30b ), wherein the additional section ( 30a . 30b ) by means of variable extrusion cohesively with the base section ( 20 ), characterized in that the basic section ( 20 ) of a first material and the additional section ( 30a . 30b ) consists of a second material, wherein the second material has a different thermal expansion coefficient than the first material. Sealing strip according to claim 14, characterized in that the additional section ( 30a . 30b ) extends at a predetermined length in the longitudinal direction. Sealing strip according to claim 14 or 15, characterized in that the additional section ( 30a . 30b ) has a longitudinally varying cross-section. Sealing strip according to claim 16, characterized in that the cross section of the additional section ( 30a . 30b ) continuously changed in the longitudinal direction. Sealing strip according to one of claims 14 to 17, characterized in that the base section ( 20 ) a holding section ( 21 ) and a sealing section ( 26 ), wherein the holding section ( 21 ) and the sealing section ( 26 ) are cohesively connected to one another by the extrusion. Sealing strip according to claim 18, characterized in that the holding section ( 21 ) is U-shaped in cross-section and a first leg ( 22 ), a second leg ( 23 ) and a base section ( 24 ), wherein the base section ( 24 ) the first leg ( 22 ) with the second leg ( 23 ) connects. A sealing strip according to claim 19, characterized in that the first leg ( 22 ) or the second leg ( 23 ) with the additional section ( 30a . 30b ) is provided. Sealing strip according to claim 19 or 20, characterized in that the base section ( 24 ) with the additional section ( 30a . 30b ) is provided. Sealing strip according to one of claims 18 to 21, characterized in that the sealing section ( 26 ) with the additional section ( 30a . 30b ) is provided. Sealing strip according to one of claims 18 to 22, characterized in that the holding section ( 21 ) at least one retaining lip ( 25 ) having. Sealing strip according to one of the claims 18 to 23, characterized in that the sealing portion ( 26 ) at least one hollow chamber ( 27 ) or a sealing lip. Sealing strip according to one of claims 18 to 24, characterized in that the holding section ( 21 ) or the sealing section ( 26 ) consists of the first material. Sealing strip according to one of claims 14 to 25, characterized in that the first material or the second Material an elastomer, preferably ethylene-propylene-diene rubber (EPDM), a thermoplastic elastomer (TPE) or a vulcanized thermoplastic Elastomer (TPV), is.