WO1994029144A1

WO1994029144A1 - Extruded sealing section and shaping tool

Info

Publication number: WO1994029144A1
Application number: PCT/EP1994/001106
Authority: WO
Inventors: Hans-Volker Buchholz
Original assignee: Meteor Gummiwerke K.H. Bädje Gmbh & Co.
Priority date: 1993-06-05
Filing date: 1994-04-09
Publication date: 1994-12-22
Also published as: DE9308418U1

Abstract

A sealing section (1) has a metal-reinforced elastomeric securing strip of substantially U-shaped cross-sectional area which can be secured to a coachwork pillar to the sealed and an elastomeric sealing strip fixed to the securing strip and acting together with a counter-member of the coachwork for sealing purposes. There are critical regions with special deformation of the sealing section (1) when the latter is in its fitted position. Without special measures, the sealing strip would probably be undesirably kinked in these critical regions. Only by being heated to a temperature above the manufacturing temperature of the sealing section (1) and subsequent cooling can the sealing section (1) be given at least approximately the permanent special deformation in a recess (29) in a heatable shaping tool (2) corresponding to the special deformation.

Description

DESCRIPTION

Extruded sealing profile and mold

The invention relates to an extruded sealing profile according to the preamble of claim 1 and a molding tool according to the preamble of claim 3.

Such sealing profiles are found e.g. in motor vehicles for sealing trunk lids and rear doors, in the passenger area for sealing the side doors and in the engine compartment for sealing the water tank and from air inlet chambers to the passenger compartment. These sealing profiles are extruded, generally co-extruded from several components, and have at least one sealing tube and / or a sealing lip as the sealing strand. The sealing strand can in particular consist of soft rubber or foam rubber.

The body panel web on which the sealing profile is to be clamped follows the body opening to be sealed in two dimensions or three dimensions. The result of this is that here and there the body panel web also describes relatively narrow radii <60 mm. The bends can be made both in the plane of the sealing profile and at right angles to it, or in any orientation. In the latter case, three-dimensional deformations or warping of the sealing profile occur when the sealing profile is installed. In all of these cases, and especially in border fall, there is a risk that the elastomer sealing strand of the sealing profile will buckle on the body panel web during or after the mounting of the sealing profile. Such kinks are optically unsightly on the one hand and on the other hand impair the sealing effect of the sealing profile. The type of the at least one elastomer used and the geometry of the sealing profile and in particular the sealing strand also have an influence on the tendency to buckle.

The material cross section of the sealing strand cannot be increased arbitrarily, because with its enlargement the closing forces for the counter element of the body, e.g. the trunk lid, the tailgate, the side doors or the bonnet rise. The consequence would be e.g. slamming side doors too hard, which can lead to noise and undesirable pressure surges in the passenger compartment.

Various proposals have already been made to counteract the tendency of the sealing strands to buckle.

So you first made complex profile modifications. An increase in the cross-sectional area of the sealing strand over the entire extruded length led on the one hand to higher material costs and on the other hand to the aforementioned, undesirable increase in the closing forces for the counter element of the body. Attempts have also been made to locally enlarge the profile cross section only where there was a risk of kinking. This was done in a very complex manner by means of vario nozzles during the extrusion.

In the case of tubular sealing strands, the tendency to kink through an inner profile has also already been attempted or counter profile. These were, for example, tubular soft or foam rubber inserts or Moosgu fill pieces.

Finally, attempts have been made to reduce the risk of kinking by locally foaming tubular sealing strands with soft polyurethane (PU) integral foams. For this purpose, the foaming compound was injected through separate holes in the tubular sealing strand. The disadvantage of these holes was that the hose wall was weakened and kinks were often introduced. Moreover, this known procedure is expensive to manufacture and causes problems in the disposal of unreacted components and in rinsing and cleaning solutions.

From DE 33 06 774 AI it is known per se

Build up butt seal 3 of safety glasses 1 from two elastic foam layers 4, 5, between which a heating element 6 is formed from aluminum foil. The foam layers consist of a thermoformable material, e.g. Low density PE. If electrical voltage is applied to connection points 8 of the radiator 6 when the protective glasses are on, the foam heats up to its thermoforming temperature, so that the shape of the butt seal 3 adapts to the head shape of the wearer of the protective glasses. Then the heating circuit is interrupted, and the butt seal cools and preserves the deformation obtained.

From DE 69 02 243 U a one-piece oil pan seal 1 is known per se, which is mechanically deformed three-dimensionally. A metallic support 8 designed as a sheet metal strip is covered on both sides with adhesive rubber layers 9, 10 which are Bends of the seal 1 have waffle-like depressions 11. At bending points 9 additional molded pieces 12 made of foam rubber are glued to the outer rubber layer.

From DE 34 17 128 C2 it is known per se to two-dimensionally deform V-shaped profile strands 1 with a metal strip 4 as a stiffening insert before the profile strand is installed. This is done by stretch bending. For this purpose, the profile strand 1 is inserted into a recess 6 of a strip-shaped die 5. In a V-shaped incision in the extruded profile, an extension 8 of a male strip 7, also in the form of a strip, engages. Die and patrix are made of rubber-elastic material and are tensioned by a tension cable 12, 13 and end turnbuckles 14, 15 to a linear unit. This unit is deformed by a guide template 20, the metallic stiffening insert 4 taking on the shape of the outer contour 21 of the guide template 20 and essentially maintaining this shape when the profile strand 1 has been formed from the molding tool.

From GB 2 240 823 A it is known per se to prevent a sealing lip 36 of a sealing profile 10 from undesired deformation by molded-on hoses 82, 84 running parallel to one another when the sealing profile is bent inwards or outwards.

From DE 36 28 448 AI it is known per se to improve the bendability of a sealing profile by special design of a metallic reinforcement 6. For this purpose, the metallic reinforcement of the fastening strand has a U-shaped cross section and is provided with alternating slots 18 on the sides. There are not any disclosed special means to protect a sealing strand 12 of the sealing profile from undesired deformation in bending areas.

From US 4,310,164 A it is known per se in a similar way to improve the bendability of such sealing profiles. Here, the U-shaped metallic support is slit transversely in a special way. In addition, a non-stretchable thread 7 can be molded in at the transition between the fastening strand 6 and the sealing strand 8.

From DE 40 01 055 AI it is known per se to produce seamless skirting board corner pieces in the form of an outside corner 10 and an inside corner 11 in a special way. For this purpose, an essentially flat, plate-shaped blank made of thermoplastic material is heated to thermoplastic deformability, deformed according to the three-dimensional shape of the corner piece, cooled while maintaining the shape and finally cut. The deformation can take place in a multi-part form.

The object of the invention is to reduce the risk of kicking for the elastomer sealing strip with simple and inexpensive means.

This object is achieved for the sealing profile by the features of claim 1. The particular deformation can be a two-dimensional deformation with a relatively narrow bending radius, as well as a three-dimensional deformation including twisting of the sealing profile around its longitudinal axis. Thanks to the thermal reshaping, the sealing strand can be shaped accordingly in its particular deformation without any additional known measures stabilize its installation position so that the risk of the sealing strand buckling is avoided or considerably reduced during and after installation.

The features of claim 2 also promote this shape stabilization of the elastomer sealing strip.

The aforementioned object is also achieved by the molding tool according to claim 3. At least part of the molding tool receives the area of the sealing profile to be deformed when the molding tool is open. After the mold has been closed, the part of the sealing profile to be deformed is in a position supported by the mold, in which the sealing profile is thermally deformed.

The features of claim 4 can be achieved that the kink-free shape of the sealing profile largely corresponds to its installation position, even before the installation is carried out.

Further features and advantages of the invention result from the following description of an exemplary embodiment with reference to the drawings. It shows:

1 shows a thermally formed, extruded sealing profile,

2 shows the sectional view along line II-II in FIG. 1 in an enlarged view,

3 shows the top view of a frame made of the sealing profile for sealing a trunk lid of a motor vehicle and Fig. 4 is a perspective view of an open

Forming tool for the thermal shaping of the sealing profile.

Fig. 1 shows a portion of a sealing profile 1 for use in body construction. The sealing profile 1 was first produced linearly in the usual manner by coextrusion and subsequently thermally formed in a molding tool 2 (FIG. 4).

The sealing profile 1 has a metal armored elastomer fastening strand 4 which can be glued onto a body panel web 3 to be sealed (FIG. 2). An elastomer sealing strand 5, which cooperates sealingly with a counter element of the body, is fastened to the fastening strand 4. The sealing strand 5 has a sealing hose 6 and a sealing lip 7 fastened to the outside of the sealing hose 6, preferably molded on by coextrusion.

For installation in the body, the sealing profile 1 must be deformed more or less, starting from its original, co-extruded straight shape, in order to be able to follow the course of the body panel web 3 (FIG. 2). Here and there, critical areas arise, such as the critical area 8 in FIG. 1, with a particular deformation of the sealing profile 1 in its installed position. If no countermeasures are taken, this particular deformation can lead to an undesirable kinking of the sealing strand 5.

In the exemplary embodiment shown in FIG. 1, a relatively narrow bending of the sealing profile 1 takes place in the critical area 8 in a plane indicated by an axis cross 9. This bend a twist about the longitudinal axis of the sealing profile 1 is also superimposed. The torsion is indicated in FIG. 1 by a broken cross 10.

As a result of the thermal treatment according to the invention, the critical area 8 is thermally reshaped in such a way that it subsequently has at least approximately its installation position without the sealing strand 5 being kinked.

2, the sealing tube 6 and the sealing lip 7 are co-extruded from foam rubber. The sealing strand 5 is further co-extruded with the fastening strand 4 and vulcanized along a coupling surface 11 to the fastening strand 4 having the soft rubber.

The fastening strand 4 is essentially U-shaped and has a metallic reinforcement 12 in

Form a bracket. From the fastening strand 4, sealing lips 13 extend inwards, which, when the sealing profile 1 is pressed onto the body sheet metal web 3, bear against the body sheet metal web 3 under elastic prestress, as is indicated on the right by the center line 14 in FIG. 2.

In certain applications, permanently elastic sealing paste 15 can be introduced into the fastening strand 4 above to increase the sealing effect. The fastening strand 4 is provided with a cover membrane 16 on the sealing side of the sealing profile 1. A continuous cavity 17 is located between the cover membrane 16 and the actual body of the fastening strand 4.

3 is the sealing profile 1 formed into a frame 18 which is to be clamped onto the body panel web of a trunk opening of a motor vehicle. In its installed position, the frame 18 will seal a trunk lid.

The frame 18 has two critical areas 19, 20 and 21 opposite each other with respect to a plane of symmetry of the frame 18, in which the sealing strand 5 (FIG. 1) would have to be expected without the thermal deformation of the sealing profile 1 according to the invention .

In the critical areas 19 there is essentially a bending of the sealing profile 1 with a relatively narrow radius in a horizontal plane. In the critical areas 20 there is essentially a bending of the sealing profile 1 in a vertical direction

Level down and a deflection of the sealing profile into a connecting section 22. The connecting sections 22 establish the connection to a horizontal closing section 23 of the frame 18 via the critical areas 21. In the critical areas 21, in addition to a bend in the sealing profile 1, there is also a twist about its longitudinal axis. All of these critical areas 19 to 21 can be mastered according to the invention without risk of kinking for the sealing strand 5 (FIG. 1).

In the middle, the closing section 23 has a joint 24 at which the two free ends of the sealing profile 1 are connected to one another in a manner known per se.

4 has a lower part 25 and an upper part 26, each of which is not shown. Neten means are heated and movable relative to each other in the vertical direction according to arrows 27 and 28.

Fig. 4 shows the mold 2 in its open position. The sealing profile 1 is inserted into a mold recess 29 in the lower part 25. The upper part 26 is then moved downwards in the direction of the arrows 28 until its upper part of the mold recess has laid over the upper region of the sealing profile 1 and the mold tool 2 is closed. In the closed position of the molding tool, the sealing profile 1 is further heated until the desired thermal deformation of the sealing profile 1 is completed. Then the molding tool 2 is opened again in the position shown in FIG. 4, and the thermally formed sealing profile 1 can be removed.

The shaped recess 29 can be designed in such a way that the thermally formed sealing profile 1 after it has been removed from the molding tool 2 and after a possible slight springing open has at least approximately the shape which corresponds to its later installation position on the body panel web. In this case, a buckling of the sealing strand 5 (FIG. 1) is no longer to be expected even in the subsequent assembly of the sealing profile 1 on the body panel web.

As elastomers for the strands 4, 5 of the sealing profile 1, e.g. the following substances are used:

Foam rubber with a hardness of 10 to 30 Shore-A or soft rubber with a hardness of 30 to 70 Shore-A, both made, for example, of EPDM, SBR,

CR,

ECO,

Blending (blending) of EPDM with SBR with an EPDM weight fraction of 20 to 90%,

Blended from EPDM with SBR and / or Polyoctenamer, or

NBR.

The following can be used e.g. also the following thermoplastic elastomers (TPE):

TPE based on styrene ethylene butylene styrene

(S-EB-S),

TPE based on styrene butadiene styrene (SBS),

TPE based on styrene isoprene styrene (SIS), TPE based on elastomer alloys as TPO blends or TPO alloys, e.g. of networked.

EPDM / propylene blend (EPDM / PP) or

Ethyleneπvenylacetat / vinylidene chloride (EVA / PVDC) or TPE based on thermoplastic polyurethanes (TPU).

The profile strands, e.g. 4 and 5 are each formed by an elastomer extruder and then vulcanized to one another along the interfaces in contact with one another with or without a coupling layer which promotes the bond. Thus there is a chemical bond of sufficient strength between the profile strands.

Claims

PATENT CLAIMS

1. extruded sealing profile (1),

with a metal-reinforced elastomer fastening strand (4) which can be clamped onto a body panel web (3) and is essentially U-shaped in cross-sectional area,

and with an elastomer sealing strand (5) fastened to the fastening strand (4) and interacting sealingly with a counter element of the body,

characterized in that in every critical

Area (8; 19 to 21) with a particular deformation of the sealing profile (1) in its installation position, in which critical area (8; 19 to 21) an undesirable kinking of the sealing strand (5) would otherwise be expected, the sealing profile (1 ) in a mold recess (29) corresponding to the particular deformation of a heatable molding tool (2) is provided at least approximately with the permanent special deformation free of kinks only by heating to a temperature value above a manufacturing temperature of the sealing profile (1) and subsequent cooling.

2. Sealing profile according to claim 1, characterized gekennzeich¬ net that the material structure of the sealing profile (1) after cooling is adapted to the particular deformation and reoriented.

3. Forming tool (2) for producing the sealing profile

(1) according to claim 1 or 2,

characterized in that the molding tool (2) is divided into several parts (25, 26),

that the parts (25, 26) in their closed state enclose a mold recess (29) which receives a section of the extruded sealing profile (1) to be provided with a permanent special deformation in accordance with its installation position on a body panel web (3),

and that at least a part (25, 26) of the molding tool

(2) can be heated such that the sealing profile (1) reaches a temperature above its manufacturing temperature.

4. Molding tool according to claim 3, characterized in that the mold recess (29), deviating from the particular deformation, is designed such that the thermally deformed section of the sealing profile (1) after cooling and after a certain springing up at least approximately has special deformation corresponding to its installation position.