WO2008141630A2

WO2008141630A2 - Lamp socket for an electric lamp

Info

Publication number: WO2008141630A2
Application number: PCT/DE2008/000859
Authority: WO
Inventors: Peter Helbig; Alexander Vogel; Andreas Koch; Karl-Heinz Quadfasel; Gottfried W. Ehrenstein; Simon Amesoder; Mike Szameitat; Matthias Scholz
Original assignee: Osram Gmbh; Schempp + Decker Präzisionsteile und Oberflächentechnik GmbH; Hubert Stüken GmbH & Co. KG; Universität Erlangen-Nürnberg, Vertreten Durch Die Kontaktstelle Für Wissens-Und Technologietransfe R; Universität Erlangen-Nürnberg, Vertreten Durch Den Lehrstuhl Für Kunststofftechnik
Priority date: 2007-05-22
Filing date: 2008-05-21
Publication date: 2008-11-27
Also published as: WO2008141630A3

Abstract

A lamp socket for an electric lamp, in particular, for a motor vehicle headlamp with a plastic socket part is disclosed, with a first section made from a higher meting plastic in a region adjacent to the lamp bulb and a second section made from a lower melting plastic in a region of mechanical stress. Savings can thus be made in cost-intensive higher melting plastics whilst at the same time guaranteeing a longer service life in the region of mechanical stress.

Description

Lamp socket for an electric lamp

Technical area:

The invention is based on a lamp base for an electric lamp, in particular for a motor vehicle headlight lamp, with a plastic base part.

State of the art

The document DE 198 55 412 Al discloses a vehicle headlamp with a metal-plastic base, wherein L-shaped tabs are received in a plastic base part. On the plastic base part is a silicone sealing ring. In order to meet the increased demands on the temperature resistance of the lamp cap, preference is given to using high-temperature-resistant plastic, such as PPS (polyphenylene sulfides). In order to keep the amount of plastic used low, the plastic base part is mechanically optimized.

A disadvantage of such materials with high temperature resistance is that they are brittle. In the region of connection sections, in which the lamp cap is electrically connected, protruding sections such as latching lugs are therefore at risk of fracture. In addition, the additional necessary sealing ring, which is preferably made of silicone, manufactured and assembled as a separate component, which leads to additional manufacturing effort. In addition, the plastic base is often internally provided with a Dichtverguss for sealing the contact lugs, whereby an additional Vergießmaschine is necessary. Presentation of the invention

The object of the present invention is to provide a lamp base for an electric lamp and a method for producing a lamp base, in which thermal and mechanical requirements for the lamp base are taken into account and a simple production process is possible.

This object is solved by the subject matter of claims 1 and 6.

Particularly advantageous embodiments can be found in the dependent claims.

A lamp base is provided for an electric lamp, in particular for a motor vehicle headlamp with a plastic base part, which has a first section of a higher melting and / or higher temperature resistant plastic in a region adjacent to the lamp vessel and a second section of a lower melting and / or or lower temperature resistant plastic in a range of mechanical stress. In this way, costly, higher melting plastic can be saved, while at the same time in the field of mechanical stress a longer life can be secured. An advantage of using a lower melting, lower cost material is also the greater choice from the viewpoint of adjusted performance characteristics and easier processability.

It is preferred if the melting point of the higher melting plastic is above 260 ⁰ C and the melting point of the lower melting plastic is below 260 ⁰ C. In this way, as a higher melting plastic, for example, PPS and lower-melting plastic PA and PBT used, which leads to a cost-effective implementation of the lamp cap.

It is further preferred if the plastic base part has a third section of a polymeric material with a sealing effect. Thus, the third section can be sprayed on the lamp base.

In a further development, the third section is arranged to the lamp vessel facing flange portion of the lamp cap, whereby a seal adjacent to the lamp vessel while ensuring small dimensions of the lamp cap can be implemented.

In a development, the third section is provided between a contact lug and the first or second section of the plastic base part. In this way, a sealing effect between the contact lug and plastic base part can be implemented.

In a method according to the invention for producing a lamp cap, the steps are used:

Forming a first portion of a plastic base part of a higher melting plastic under introduction of contact lugs, forming a second portion of the plastic base part of a lower melting plastic on the first section. In this way, a lamp base can be provided in a simple manner by two injection molding operations, which can be used both thermally and improves mechanical and mechanical requirements compared to the state of the art.

In a further development, after the formation of a second section, the formation of a third section of a polymeric material with a sealing effect takes place on the first and / or second section. Thus, by a further injection process in a simple manner, a sealing portion are provided on the lamp cap.

It is preferred if the third section is provided between a contact lug and the first or second section of the plastic base part. Thus, around a contact lug around an increased sealing effect can be implemented at the same time cost-effective production of the lamp cap.

Brief description of the drawings

In the following, the invention will be explained in more detail with reference to an embodiment. The figures show:

1 shows a cut lamp base with incorporated holding device for a lamp vessel,

2 shows a sectional view through the lamp cap according to the present invention,

Fig. 3 is a partial plan view of the lamp cap of Figure 2 and

Fig. 4 is a schematic diagram of the manufacture of the lamp cap according to the invention. Preferred embodiment of the invention

FIG. 1 shows a lamp arrangement 1 according to the invention with a schematically illustrated lamp base 2.

The lamp base 2 has a plastic base part 4 with a connection section 6. The connection section 6 is designed like a bush. In the interior 8 of the connection section 6, a contact section 10 of a contact lug 12 projects. The contact lug 12 is formed substantially L-shaped and has a connecting portion 14 which are connectable to power supply wires 16, 18 of the lamp 20. The portion of the contact lug 12, to which the contact portion 10 is connected to the connecting portion 14, is cast in the plastic base part 4.

At right angles to the interior 8, a flange portion 22 is provided on the plastic base part 4, via which the lamp base 2 can be fastened by means of a sealing ring 26 to a reflector 24 shown in dashed lines in FIG. Radially within the flange portion 22, a connection space 28 is provided in the lamp base 2, in which the connecting portion 14 of the contact lug 12 protrudes. In the flange portion 22, an annular support sleeve 30 is further anchored, preferably by ultrasonic welding, in which a cup-shaped holding part 34 is supported via an intermediate ring 32, in which the pinch 36 of a lamp vessel 38 of the lamp 20 is received. At the end portion of the lamp vessel 38 opposite the pinch 36, a light-absorbing coating 40 is provided. The filament 42 shown in Figure 1 is electrically connected to the power supply wires 16, 18.

In the preferred embodiment of the invention, the lamp 20 is a single-filament halogen incandescent lamp intended for use in a motor vehicle headlight. The lamp base 2 is preferably of the types H8, H9 or HIl, which can be used in particular for high beam and fog lights.

FIG. 2 shows a sectional view through the lamp base 2 according to the invention in more detail than in FIG. The lamp base 2 has the plastic base part 4, which has a base portion 60, a lower portion 62 adjacent thereto, and a sealing portion 64 provided from the side of the lamp base. The determination of the sections takes place after the function of the different parts of the lamp cap in operation.

The flange portion 22 of Figure 1 forms part of the base portion 60 and is preferably made of higher melting plastic. Such plastics are characterized by high strength, stiffness and hardness as well as heat distortion resistance, and have, for example, a melting point greater than 260 ⁰ C. An example is PPS (polyphenylene sulfides).

Since the flange portion 22 receives the lamp vessel 38, the highest temperatures of the lamp cap are to be expected on this. Therefore, the higher melting plastic is used for the base portion. At the same time, there is also the L-shaped contact lug 12 in the base portion, because of the power supply lines 16 and 18 of the lamp 20, the contact lug 12 heat is supplied and this can be delivered via the contact lugs to the surrounding material.

The lower portion 62 of the plastic base part 4 has the connection portion 6 with the interior 8 and is continued by a bottom portion 66 below the base portion 60. Thus, opposite sides of the base portion 60 in the region where the contact lug 12 is received therein are enclosed by the lower portion 62 and thus kept mechanically stable.

The lower portion 62 is made of a lower melting plastic, for example, a plastic having a melting point below 260 ⁰ C. As materials, for example, PA (polyamide) or PBT (polybutylene terephthalates) are usable. Such lower melting plastics preferably have a higher mechanical strength and are preferably less brittle than higher melting plastics. In addition, these are cheaper and at low temperature, ie easier to process. When using highly filled PPS, which is brittle, this can be made tougher by bonding with, for example, thermoplastics.

FIG. 3 shows a plan view of the base section 60 with sealing section 64 and adjacent lower section 62. As can be seen from this figure, a latching nose 68 is formed in the region of the connection section 6, via which a plug can be applied to the connection section 6 and can be mechanically stable , Due to the use tion of the lower melting plastic for the lower portion 62, this latching nose 68 can be formed mechanically more stable than in the prior art and thus the life of the lamp cap can be increased.

In FIG. 2, a sealing section 64 is provided on the flange section 22 surrounding the base section 60, which has the sealing ring 26 and the contact lug sealing section 70. The area with the sealing ring 26 of the sealing portion 64 and the area of the contact tab Abdichtabschnitts 70 are connected to each other via a connecting channel 72, which ensures that when forming the sealing ring 26, the sealing material, such as silicone, also reaches the contact tab Abdichtabschnitt 70.

With the plastic base part 4 according to the invention, it is possible to achieve high mechanical stability in the region of the connection section and to provide a high temperature resistance in the region of the flange section 22. At the same time, a suitable sealing compound can be provided at the required sections, such as sealing ring 26 and contact tab sealing section 70.

The production of such a lamp cap 2 is preferably carried out as follows.

After providing the contact lugs, a pre-molded part made of a higher-melting plastic is injected in a first injection process, the latter having the contact lugs 12 and the base section 60. Subsequently, this preform is inserted into another tool and with the lower melting Plastic encapsulated, so that the lower portion 62 of the plastic base part 4 is formed.

If increased sealing requirements are to be met, the lamp base comes in a third tool and the third component of the sealing ring 26 is molded, wherein the sealing material passes through connection channel 72 in the region of the contact tab sealing portion 70.

As a result, the amount of higher melting plastic such as PPS used can be reduced due to the use of the lower melting plastic in the lower portion 62, and at the same time, stable locking lugs can be provided on the terminal portion 6. Since the sealing ring 26 and the contact lug Abdichtabschnitt 70 are formed by injection molding, the Vergießmaschinen according to the prior art, which have provided there for the Dichtverguss omitted.

FIG. 4 schematically shows a machine for producing lamp sockets according to the invention. This machine has stamped strip feeders 80a, 80b, which provide a respective contact lug at a punching station 82a, 82b and load a workpiece carrier at the loading station 84a, 84b. Via the carrier system 86, the workpiece carriers reach the measuring station 88, at which an assembly control and a temperature measurement take place. The workpiece carriers are fed to a first injection molding machine 90 and a second injection molding machine 92, and the base portion 60 and the lower portion 62 are formed on the contact lugs. After removal of the pedestals at the extraction station 94, The finished high-quality lamp base for Gutteilablage 96. The formation of the sealing portion 64 is not shown in Figure 4, but can be done following the processing in the second injection molding machine 92. In a modification of the machine according to FIG. 4, the carrier system 86 is designed as a circulatory carrier system.

Thus, an effective manufacturing method for forming a lamp cap having at least two different types of plastic can be implemented in a simple manufacturing process.

There is provided a lamp base for an electric lamp, in particular for a motor vehicle headlamp with a plastic base part having a first portion of a higher melting plastic in a region adjacent to the lamp vessel and a second portion of a lower melting plastic in a region of mechanical stress , In this way, more expensive higher-melting plastic can be saved, while at the same time a longer service life can be ensured in the area of mechanical stress.

Claims

claims

A lamp base (2) for an electric lamp, in particular for a motor vehicle headlamp, comprising a plastic base part (4) having a first portion (60) of a higher melting and / or higher temperature resistant plastic in a region adjacent to the lamp vessel, and a second Section (62) made of a lower melting and / or lower temperature resistant plastic in a region of mechanical stress up.

2. Lamp base according to claim 1, wherein the melting point of the higher melting plastic is above 260 ⁰ C and the melting point of the lower melting plastic is below 260 ⁰ C.

3. Lamp base according to claim 1 or 2, wherein the plastic base part (4) has a third portion (64) made of a polymeric material having a sealing effect.

4. Lamp base according to claim 3, wherein the third portion (26) adjacent to the lamp vessel facing fl ange flange portion of the lamp cap is arranged.

5. A lamp cap according to claim 3 or 4, wherein the third portion (70) between a contact lug (12) and the first or second portion (60, 62) of the plastic base part (4) is provided.

6. A method of manufacturing a lamp cap, comprising the steps of: forming a first portion (60) of a plastic base member from a higher melting plastic material incorporating tabs (12), forming a second portion (62) of the plastic base member from a lower melting plastic on the first portion (60).

A method as claimed in claim 6 including the step of forming a third portion (70) of a polymeric material having a sealing effect at the first and / or second portions after forming a second portion (62).

8. The method of claim 6 or 7, wherein the third portion (64) between a contact lug (12) and the first or second portion (60, 62) of the plastic base part (4) is provided.