The invention relates to a profile arrangement with a support part in the form of a plastic moulding and an at least sectorwise, elastically flexible switching strip profile, said switching strip profile having a holding portion connected to the support part. The invention also relates to a method for the manufacture of a profile arrangement having a support part in the form of a plastic moulding and an at least sectorwise, elastically flexible switching strip profile.
DE 10349 650 A1 discloses a profile arrangement in which an elastically flexible switching or control profile has a holding portion drawn into a slot in a support part. The switching profile with the holding part is extruded, whereas the support part is in the form of an injection moulding. The slot has in the vicinity of its opening alternating projections and recesses, said projections forming an undercut behind which engages the holding portion of the switching profile.
It is also known to bond the holding portion of switching strip profiles to support parts, e.g. in that the holding portion is provided with an adhesive coating. To ensure a secure hold of the switching strip profile on the support part, comparatively time consuming material preparations are needed, e.g. the degreasing of the support part.
The invention aims at providing a profile arrangement manufacturable in a shorter time and in a more reliable manner from the process standpoint, together with a corresponding method for the manufacture of a profile arrangement.
According to the invention, for this purpose a profile arrangement is equipped with a support part in the form of a plastic moulding and an at least sectorwise, elastically flexible switching or control strip profile, the latter having a holding portion connected to the support part and where the holding portion of the switching strip profile is at least sectorwise integrally joined to the support part by moulding on a support part portion.
Due to the fact that the holding portion of the switching strip profile is joined to the support part by moulding on, secure fastening is obtained and the integral joint between support part and holding portion of the switching strip profile is formed during the injection moulding process of said support part. The joining of the switching strip profile and support part takes place in a single manufacturing step, which is in any case needed for manufacturing the support part. This facilitates manufacture, because there is no need with respect to said support part to carry out any preparatory work, e.g. degreasing or the like, such as occurs when the switching strip profile is bonded on. In addition, this makes possible very tight manufacturing tolerances, because the switching strip profile is always positioned in the same location relative to the support part and specifically no positioning errors can arise on placing the switching strip profile on the support part.
According to a further development of the invention the support part portion has at least one rib and the holding portion of the switching strip profile is integrally joined to a narrow side of the rib.
Ribs on the support part portion ensure a stabilization of the support part. However, as the holding portion of the switching strip profile is connected to a narrow side of the rib, during the injection moulding process less pressure has to be exerted on the switching strip profile than would be the case with full-surface contacting of the holding portion of the switching strip profile. This makes it possible to ensure that during the moulding on of the support part portion, the switching strip profile is only slightly deformed and also in the end state has an optimum cross-section for fulfilling the switching strip function.
According to a further development of the invention the support part has several ribs, which with the end portion thereof in each case project freely from a base portion of the support part, the holding portion of the switching strip profile resting on the end portions of the rib and is integrally joined thereto.
This brings about a very tight connection between support part and switching strip profile, because even in the case of a limited material thickness the ribs can well withstand bending forces acting perpendicular to their narrow sides. In addition, the pressure exerted on the holding portion of the switching strip profile and which comes into effect on injection moulding the support part, only has an effect in very small surface areas of the holding portion of the switching strip profile, because it only rests on the end portions of the ribs and consequently on a free narrow side of each rib. Thus, deformations of the switching strip profile by the pressure exerted during injection moulding can be largely avoided.
Alternatively the holding portion can have a strip or rib extending away from the switching strip profile and which following the moulding on of the support part is surrounded on both sides by the plastics material of the support part. As a result of such a design the injection moulding pressure during the injection moulding of the support part exclusively acts on the strip or rib of the holding portion of the switching strip profile, because injection moulding takes place on the latter from two opposite sides. The elastically flexible portion of the switching strip profile which assumes the actual switching function, can be so placed on the part of the holding portion not subject to the action that during the injection moulding of the support part it is not exposed to the injection moulding pressure and consequently cannot become permanently deformed.
In a further development of the invention the holding portion of the switching strip profile is provided with projections, ribs and/or steps.
This makes it possible to increase the contact surface between support part and holding portion of the switching strip profile, which improves the integral joining action.
In a further development of the invention the holding portion of the switching strip profile is provided with at least one undercut and is integrally joined to the support part in the vicinity of the undercut.
If in addition to the integral joining action there is a positive engagement between support part and holding portion of the switching strip profile, the connection between said switching strip profile and said support part can be made even more reliable. The holding portion e.g. has a cross-sectionally dovetailed, projecting strip, which is surrounded by the plastics material of the support part on moulding on the latter. Thus, apart from the integral joining action, there is a positive engagement. Alternatively or additionally it is possible to provide dovetailed slots on the holding portion which are filled by the plastics material of the support part.
In a further development of the invention the support part is constructed as an elongated strip and provided with fixing means for fixing to a vehicle body.
As a result a switching strip profile can be manufactured together with the support part as an element to be directly fitted to the car and for fixing the support part it is e.g. possible to provide expansion rivets or the like.
In a further development of the invention the switching strip profile is curved along its longitudinal direction and/or along its transverse direction.
Thus, the switching strip profile can adapt to curvatures of door or lid openings on the car. It is essential that during the moulding on of the support part the switching strip profile is fixed in its curved position. Even in the case of spatially curved paths of a switching strip profile, it is possible to ensure that the said profile is always joined to the support part in the predetermined position. Thus, with limited costs highly accurately fitting parts can be manufactured.
In a further development of the invention the holding part of the switching strip profile is at least sectorwise made from electrically conductive material. Thus, the holding part of the switching strip profile can be used as a shield electrode during the capacitive detection of obstacles.
In a further development of the invention the support part is at least sectorwise made from electrically conductive material.
Alternatively or additionally to the holding portion, in this way the support part can be used for shielding an electric field, which emanates from the switching strip profile in operation for the capacitive detection of obstacles. As the support part is intended for fitting to a car body, an electrical field for the detection of obstacles must extend away from the body. This does not generally cause a problem in the case of sheet metal bodies, but if e.g. plastic doors or lids are used, a support part made from electrically conductive material significantly facilitates the shielding of such an electrical field.
In a further development of the invention the switching strip profile has at least two conductors which are spaced from one another and run parallel to the longitudinal direction of the switching strip profile, a first conductor being constructed as a capacitor electrode for generating an electrical field and a second conductor as a shield electrode for influencing the electrical field. The first and second conductors or also further conductors of the switching strip profile can advantageously be electrically contacted with one another during the deformation of the switching strip profile. This provides a tactile detection in addition to the contactless, capacitive detection of obstacles. On the side of the first conductor essentially facing the second conductor it is possible to provide in spaced manner with respect to said first conductor at least one third conductor located within the switching strip profile. Such a third conductor can be used for diagnostic purposes or also for influencing the electrical field emanating from the first conductor. In the case of a third conductor provided for diagnostic purposes it is e.g. possible to establish by means of the third conductor whether an electrical field emanates from the first conductor and whether the capacitive sensor is still functional. In the case of the influencing of the electrical field the third conductor can e.g. be placed on earth or ground potential so as to influence the electrical field from the first conductor. Finally, the third conductor can be at the same potential as the first conductor in order to enlarge the sensor surface. It is obviously possible to combine with one another the aforementioned functions of the third conductor, in that switching means are provided so as to make it possible to use the third conductor for different functions. Considered in the longitudinal direction of the switching strip profile various functions of the third conductor can also be implemented spatially in order to satisfy spatial considerations in the opening area of a vehicle door or lid.
The problem of the invention is also solved by a method for the manufacture of a profile arrangement with a support part in the form of a plastic moulding and an at least sectorwise, elastically flexible switching strip profile, in which the following steps are provided:
The inventive method ensures that the switching strip profile is always fixed on the support part in the precisely predetermined position. This takes place by simply inserting the switching strip profile in a plastic injection mould and then moulding the support part. Following the removal of the support part with the moulded on switching strip profile, a substantially ready to install component is obtained.
In a further development of the invention the switching strip profile is placed in a matching slot of a plastic mould and a vacuum is applied to the slot to suck on the switching strip profile.
In this way the switching strip profile can be fixed in the plastic injection mould. This is particularly important if the switching strip profile in the plastic mould is to assume a curved and optionally even spatially curved shape.
Switching strip profiles are extruded and consequently initially have a straight or linear shape. Thus, if switching strip profiles are to be given a curved shape, there are necessarily certain springback forces. The application of a vacuum to a slot in the plastic mould can reliably prevent a springing back of the switching strip profile. Following the moulding of the support part, the switching strip profile is integrally joined to said support part and is therefore reliably held in the predefined shape.
Further features and advantages of the invention can be gathered from the claims and the following description of preferred embodiments of the invention. Individual features of the different embodiments can be combined in a random manner without passing beyond the scope of the invention. In the drawings show:
The switching strip profile 14 is constructed as a so-called tactile switching strip and is able to detect obstacles if they come into contact with said switching strip 18. Alternatively or additionally the switching strip 18 can be constructed as a contactless sensor, where obstacles are detected capacitively and in contactless manner by means of an electrical field. In this case from the first conductor 22 emanates an electrical field and the second conductor 24 is grounded or earthed in order to orient the electrical field in the detection direction. The change to the electrical field as a result of an obstacle can then be detected by means of a suitable evaluation electronics.
The left-hand narrow side and underside of the holding portion 16 in
The switching strip profile 36 is designed both for a capacitive, contactless detection of obstacles and also for a tactile detection of obstacles. In the vicinity of its flexible plastic material switching strip, the switching strip profile 36 has a cavity 29 and adjacent to the latter a first conductor 31 with a rectangular cross-section. In the plastic of the switching strip, outside cavity 29 is provided a cross-sectionally U-shaped, second conductor 33. On the side of the first conductor 31 facing the second conductor 33 is provided a third conductor 35, which merely comprises strand wires. Finally, adjacent to the cavity 29 on the side thereof facing the first conductor 31 is provided a fourth conductor 37. All the conductors of the switching strip profile 36 are only diagrammatically represented in
For a capacitive detection of obstacles the first conductor 31 is used as a capacitor electrode from which emanates an electrical field. Towards the back of the first conductor 31 the electrical field is shielded by the U-shaped, second conductor 33, which is earthed or grounded. If an obstacle enters the electrical field emanating from the first conductor 31, it can be detected by suitable evaluation electronics and a switching signal can be generated. To improve the shielding of the electrical field from the first conductor, the holding portion 38 can also be made from conductive plastics material and grounded or earthed.
The third conductor 35 can be used for different purposes. It can firstly be used as a test electrode to establish whether an electrical field emanates from the first conductor 31 and consequently the capacitive sensor is ready to operate. Alternatively the third conductor 35 can be placed on the same electrical potential as the first conductor 31 and consequently contributes to an enlargement of the sensor surface. Finally, the third conductor 35 can be grounded or earthed, in order to optionally influence the electrical field from the first conductor 31.
For operation as a tactile switching strip which can simultaneously take place for capacitive operation, a resistance between the first conductor 31 and the fourth conductor 37 is detected. If the switching strip of the switching strip profile 36 is compressed by an obstacle, the first conductor 31 comes into contact with the fourth conductor 37, so that a short-circuit occurs between the two conductors 31, 37 and this is detected and used for generating a switching signal.
The switching strip profile 64 is fixed to a cross-sectionally approximately L-like portion of support part 66 projecting from the sheet metal structure 58. On contact with an obstacle said L-like portion of support part 66 can be additionally deformed in order to ensure a certain give on contact with an obstacle.
In the case of capacitive detection of obstacles, an electrical field emanates from the switching strip profile 64 and said field is modified by the penetration of an obstacle into the gap between tailgate 50 and body 52. This change to the electrical field is then detected. To influence the electrical field from switching strip profile 64 and concentrate the same in the area of the gap between tailgate 50 and body 52, support part 66 can be made from electrically conducting plastic. The support part 66 is then electrically contacted with the tailgate sheet metal structure 58 in order to shield the electrical field from switching strip profile 64 towards tailgate 50. In the same way, the holding portion of switching strip profile 64 which is joined to the support part 66 can also be made from electrically conductive material.
As can be gathered from
The underside of support part 72 is also provided with several substantially parallel, mutually spaced ribs 80, which project from the base part of support part 72 and rest with their free, projecting portion on an underside of holding portion 78. Between an underside of holding portion 78 remote from the switching strip of switching strip profile 76 and the ribs 80, during the injection moulding of support part 72 this brings about an integral joint in the vicinity of a narrow side of ribs 80. Thus, the ribs 80 hold the switching strip profile 76 in the manner of cantilevered beams or girders. This significantly reduces a contact surface between support part 72 and holding portion 78 of switching strip profile 76 in a pressure-sensitive area, so that during the moulding of support part 72 there are no permanent deformations to the holding portion 78 and therefore the entire switching strip profile 76. Specifically a contact surface between support part 72 and holding portion 78 is reduced in the area where the compressive forces could compress the switching strip of switching strip profile 76 on injection moulding support part 72. In the area precisely facing the switching strip, on the holding portion 78 are only placed the projecting ends of ribs 80. Compressive forces on the holding portion 78 are much reduced in the direction of the switching strip as compared with the situation where the top underside of holding portion 78 in
Number | Date | Country | Kind |
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10 2007 050 352.2 | Oct 2007 | DE | national |