WO2012000525A1

WO2012000525A1 - Metal-plastic bond

Info

Publication number: WO2012000525A1
Application number: PCT/EP2010/003943
Authority: WO
Inventors: Christian Langer; Sebastian Täubert; Jörg Geipel
Original assignee: Pepperl+Fuchs Gmbh
Priority date: 2010-07-02
Filing date: 2010-07-02
Publication date: 2012-01-05
Also published as: CN103003023A; CN103003023B; JP5583273B2; JP2013530073A

Abstract

A process for creating a bond between a metal surface and a plastic surface, in which a collar-like bead is formed on at least one edge of the metal surface and a side surface having a shoulder-like protrusion for supporting the plastic surface is formed on the metal surface, a strip-like seal is incorporated on the protrusion before the plastic surface is placed thereon, the plastic surface is placed onto the protrusion of the side surface in such a manner that a side surface of the plastic surface is arranged alongside the side surface of the metal surface such that they impact against one another, and a form-fitting, elastically supported bond is produced by means of deformation between at least one part of the side surface of the metal surface and a part of the side surface of the plastic surface, such as to form a substantially jointless and substantially step-free transition between the metal surface and the plastic surface at the bonding site on the top side of the metal surface and of the plastic surface.

Description

Metal - plastic compound

The invention relates to a method for producing a connection according to the preamble of patent claim 1 and to a metal - plastic composite according to the preamble of patent claim 8.

Establishing reliable connections between metals and plastics is an important component in the art, especially in areas where optical control of manufacturing processes is necessary. In the field of food technology, such compounds are often subject to increased demands on the physical and chemical properties; in particular, such a composite must meet high requirements with regard to reliability and tightness, as well as comply with the corresponding standards. Furthermore, such compounds are also subject to strongly changing temperatures in the range of -40 to 120 C and strongly fluctuating pressures in the range of several bar. In order to meet the high requirements, in conventional metal - plastic compounds, the joints between the metal surfaces and the plastic surfaces by means of mechanical Fasteners, such as screws and clamps, and or chemical sealants usually protected in the form of adhesives. The disadvantage, however, is that the adhesive introduced between the sealing surfaces on the adjacent side surfaces of the metal surfaces or plastic side surfaces partially contain undesirable ingredients, possibly give them and are often not sufficiently resistant to aging. Furthermore, mechanical fasteners are expensive to produce and cause a variety of hygienic disadvantages, especially in cleaning.

Furthermore, it is desirable, particularly on the surface at the interface between the two materials form a planar as possible, add ^¬ free transition, in order to suppress a storage of substances. In general, this involves complex mechanical post-processing steps

CONFIRMATION COPY after joining the two materials necessary to ensure the required surface finish.

Against this background, the object of the invention is to provide a method for producing a connection between a metal surface and a plastic surface and a metal-plastic composite, each of which reduces the disadvantages of the prior art.

The object is achieved by a method for producing a connection between a metal surface and a plastic surface with the features of patent claim 1 or with a metal - plastic composite with the Merkmaien of claim 8. Advantageous embodiments of the invention are the subject of dependent claims.

According to the subject matter of the invention according to claim 1, a method is provided for producing a connection between a metal surface and a plastic surface, wherein on the metal surface at least one edge of a collar-shaped bead and a side surface is formed with a shoulder-shaped shoulder for supporting the plastic surface, and placed on the shoulder before placing the plastic surface a strip-shaped seal and the plastic surface is placed on the shoulder of the side surface such that a side surface of the plastic surface is juxtaposed with the side surface of the metal surface and by forming between at least a portion of the side surface of the metal surface and a Part of the side surface of the plastic surface a positive elastic-supported connection is generated, so that at the junction on the top of the metal surface and the top of the plastic surface a essentially seamless and substantially step-free transition between the metal surface and plastic surface is formed.

According to the subject matter of the invention according to claim 8 there is provided a metal - plastic composite comprising a metal surface having a surface and a side surface, the side surface forming a shoulder-shaped shoulder and a return profile perpendicular to the surface. Here, the composite has a resting on the shoulder strip-shaped seal, and a plastic surface with a side surface which rests partially shock-like manner on the side surface of the metal surface and the bottom at least partially rests on the seal on. Furthermore, the composite provides a joint that forms a substantially seamless and substantially step-free transition between the metal surface and the plastic surface on top of the metal surface and the plastic surface.

An advantage of the method according to the invention is that two different materials can be joined together without additional mechanical or chemical attachment means. Furthermore, a formation of joints and steps is suppressed at least on their surfaces. This makes it possible to form an adhesive-free composite which is largely impermeable to atmospheric gases and / or liquids. In particular, in an application in the food industry, the extensive freedom from joints of the surface and the freedom from adhesives suppresses undesired incorporation of substances or release of adhesive agents, which would worsen the hygienic or aseptic properties of the composite. Furthermore, due to the forming process in conjunction with an adapted profile guidance of the two side surfaces, a continuous transition between the upper side of the metal surface and the upper side of the plastic surface is achieved without the hitherto necessary additional post-processing steps such as polishing or milling.

In a preferred embodiment of the method, a return profile is formed by means of the forming on the side surface of the metal surface in order to secure the plastic surface against a vertical displacement relative to the metal surface. Furthermore, it is advantageous for the seal between the metal surface and the plastic surface to be made of an elastic material such as viton, rubber or composite plastics in order to produce an elastic positive locking which acts essentially perpendicular to the metal surface. In this case, it is advantageous if the outer edge of the plastic surface is chamfered appropriately in order to prevent the formation of the undercut. side surface of the metal surface to favor. According to another embodiment, it is advantageous to provide the side surface of the plastic surface with a stepped shoulder. In this case, the profile of the paragraph is suitably chosen so that during the forming only the bottom of the shoulder of the plastic surface rests on the seal and the underside, preferably at least a portion of the plastic surface between the inner edges of the opening of the metal surface in the forming process can spring through.

In another development, the plastic surface is completely enclosed by the metal surface at its outer edge. This design makes it possible, in particular using optically transparent plastics, to provide a means of controlling manufacturing processes without damaging the sensors as a result of direct contact with chemically or mechanically aggressive materials. Furthermore, it is also possible to send or receive electrical or magnetic fields through the plastic surface by selecting suitable plastics. Such fields are generally shielded from metals.

Investigations by the applicant have shown that in the case of the composite of metal plastic according to the invention, the seal is preferably designed as an elastic circumferential strip. Furthermore, the elastic properties and the geometric design of the gasket can be suitably selected as required and as a function of the forces acting on the deformation.

The invention will be explained in more detail with reference to the drawings. Here similar parts are labeled with identical names. In it show:

FIG. 1 is a schematic sectional view through the metal surface with the surface of the plastic surface lying in the unconnected state; FIG. 2 shows a schematic sectional drawing in the connected state, according to a first embodiment,

FIG. 3 shows a schematic sectional drawing in the connected state, according to a further embodiment,

Figure 4 top view of a metal surface with embedded

Plastic surface in the connected state.

The sectional drawing shown in FIG. 1 of an unconnected arrangement shows a metal surface 10 with a bead 15 formed on an edge 20 of the metal surface 10. Furthermore, the metal surface 10 has a side surface 30 with a stepped shoulder 35. On the shoulder 35 is a seal 40. Furthermore, the metal surface 10 has an opening 17 with an inner plastic surface 50. The plastic surface 50 has a side surface 55 with a stepped shoulder 60. Further, a chamfer 65 is formed on the upper edge of the plastic surface 50. According to the illustrated embodiment, the extension of the shoulder 60 is selected to be slightly larger than the extension of the shoulder 35 parallel to the surface of the plastic surface 50. Further, the extension of the heel 35 in a direction perpendicular to the surface corresponds to a sum of the thickness of the plastic surface 50 and the thickness of the gasket 40. According to the illustrated embodiment, the side surfaces 30, 55 of the plastic surface 50 and the metal surface 10 are arranged in a jar shape ,

In the figure 2 is an embodiment of the invention the metal surface 10 and the plastic sheet 50 in a connected state, that is represented by appli ^¬ extension of the forming process. Here, the side surface 30 of the metal surface with the side surface 55 of the plastic surface 50 is connected largely form ^¬ conclusive. On the surface of the metal surface 10 of the bead 15, shown in Figure 1, no longer exists because the corresponding metal of the metal surface 10 forming a return portion 75 of the side edge 30 forms a positive connection with the chamfer 65 of the plastic surface 50. Furthermore, the surface of the plastic surface 50 forms with the Surface of the metal surface 10 at the junction 70 from a stepless and seamless transition. By the deformation, the seal 40 is elastically deformed and now presses the plastic surface 50 in a direction perpendicular to the surface to the return portion 75 of the side surface 35 of the metal surface 10. Further, by means of the seal 40, the side surface 35 of the metal surface 10 relative to the side surface 55 of the plastic surface 50 sealed to form a gap 78. Depending on the size and elasticity of the circumferential seal 40 and on the geometric dimensions of the material properties of the metal and plastic surfaces to be joined and the geometry of the step-like shoulders on the side edges, both the contact pressure of the plastic surface and the metal surface can be determined Adjust the size of the gap on the side surface. Investigations by the applicant have shown that, despite a vertical gap between the seal and the side edge of the metal surface, a reliable seal in the region of the transition between the plastic surface and the metal surface is ensured.

According to an embodiment shown in FIG. 3, in the region of the side surfaces of the metal surface 10 and the plastic surface 50, a complete positive connection between the two surfaces is achieved. Accordingly, the space is completely filled by the seal arranged between the shoulder 35 and the shoulder 60.

FIG. 4 shows a plan view of a metal-plastic composite produced by means of the method according to the invention, comprising a metal surface 80 and a plastic surface 90 with different edge shapes 92, 94, 96 and 98, which have different degrees of curvature. At a connection point 100, the metal surface 80 forms a joint-free and stepless transition with the plastic surface 90. Despite the small radius of curvature in the edge shape 92, it is ensured by the corresponding ductility of the metal used that a largely joint-free and stepless transition is formed by means of the forming in the edge regions on the surface, without a mechanical aftertreatment of the surface is required. Furthermore, a reliable, mechanically strong, sealed joint without the use of mechanical or chemical fasteners, which is particularly suitable for applications in the field of food technology.

Claims

claims

Method for producing a connection between a metal surface (10) and a plastic surface (50),

in which on the metal surface (10) at least one edge (20) has a curly bead (15) and a side surface (30) with a shoulder-shaped shoulder (35) for supporting the plastic surface (50),

on the shoulder (35) before applying the plastic surface (50) a strip-shaped seal (40) is introduced,

the plastic surface (50) on the shoulder (35) the side surface (30) is placed such that a side surface (55) of the plastic surface (50) with the side surface (35) of the metal surface (10) is strung together in an abrupt,

by means of deformation between at least a part of the side surface (30) of the metal surface (10) and a part of the side surface (55) of the plastic surface (50), a positive, elastically assisted connection is produced, such that at the connection point (100) on the upper side of the metal surface (10) and the plastic surface (50) a substantially seamless and substantially step-free transition between the metal surface (10) and plastic surface (50) is formed.

A method according to claim 1, characterized in that by means of the forming on the side surface of the metal surface (10), a returning profile is formed.

A method according to claim 1 or claim 2, characterized in that the plastic surface (50) is completely enclosed at its outer edge of the metal surface (10).

Method according to one of claims 1 to 3, characterized in that on the side surface (55) of the plastic surface (50) a stepped shoulder (60) is formed. 9

5. The method according to any one of claims 1 to 4, characterized in that by the seal (40) between the metal surface (10) and the plastic surface (50) an elastic positive connection is produced, the plastic surface (50) substantially perpendicular to the Surface of the metal surface (10) presses.

6. The method according to any one of claims 1 to 4, characterized in that between the metal surface (10) and the plastic surface (50) an adhesive-free composite is formed, which is impermeable to liquids.

7. The method according to any one of claims 1 to 4, characterized in that between the metal surface (10) and the plastic surface (50) an adhesive-free composite is formed, which is impermeable to atmospheric gases.

8. Metal - plastic compound, comprising

a metal surface (10) having a surface and a side surface (30), the side surface (30) having a shoulder-shaped shoulder (359 and a receding profile perpendicular to the surface of the metal surface (10));

a on the shoulder (35) resting strip-shaped seal

(40)

a plastic surface (50) having a side surface (55) partially abutting the side surface (30) of the metal surface (10) and the underside of the plastic surface (50) partially resting on the gasket (40);

a joint (100) having on top of the metal surface (10) and the plastic surface (50) a substantially seamless and substantially step-free transition between the metal surface (10) and plastic surface (50). Metal - plastic compound according to claim 7, characterized in that the metal surface (10) has an opening (17) with a plastic surface (50) arranged therein.

Metal - plastic compound according to claim 7 or claim 8, characterized in that the seal (40) is formed as an elastic circumferential strip.

Metal - plastic compound according to one of claims 7 to 9, characterized in that the connection point (100) forms an adhesive-free transition between the side surface of the metal surface (10) and the side surface of the plastic surface (50).