Sheated-element glow plug having a particularly embedded contact element

Abstract

A sheathed-element glow plug for an internal combustion engine is described. It includes a plug housing, a connection part for the electrical current that is situated on the plug housing as well as a sheathed-element heater, which is usually in the form of a tube including an embedded heating element. The connecting part and the heating element are electrically coupled by a terminal pin and a contact element. The terminal pin and the contact element are at least partially surrounded within the housing by an electrically insulating plastic sleeve.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a sheathed-element glow plug for an internal combustion engine made up of a plug housing, a connection part for the electrical current which is situated on the plug housing as well as a sheathed-element heater, which is usually in the form of a tube including an embedded heating element. The connecting part and the heating element are electrically coupled by a terminal pin and a contact element. BACKGROUND INFORMATION [0002] The contact element together with the terminal pin and the connection area of the sheathed-element heater in the housing interior forms the positive contact. Various methods are known from the related art for securing the contact element within the housing of the sheathed-element glow plug and insulating it from the housing. [0003] Frequently sheathed-element glow plugs having a small diameter are requested. Since the electrical properties are predetermined by the sheathed-element heater and the term...

AI Technical Summary

Benefits of technology

[0005] An object of the present invention is to provide a sheathed-element glow plug having a solidly secured contact element, it being possible to secure and insulate the contact element cost-effectively.

[0007] The use of a sleeve, preferably a plastic clamping sleeve, produces a very simple insulation from the housing. In contrast to ceramic sleeves, plastic sleeves have the advantage that it is possible to manufacture them more simply and accordingly more cost-effectively. This applies in particular to sleeves having thin walls as is frequently needed in sheathed-element glow plugs.

[0009] Plastic sleeves may be easily manufactured in various sizes and shapes. An advantageous embodiment is to manufacture the plastic sleeve as a clamping sleeve.

[0011] In contrast to ceramic materials, plastics having elastic properties may also be provided. In one advantageous embodiment, the plastic sleeve has elasticity in the radial and / or longitudinal direction. The elasticity increases the robustness of the component and reduces the probability of fracture during assembly or under loads during operation.

Problems solved by technology

The clamping sleeves must therefore be made using a thin wall, which in the case of ceramic materials is associated with high manufacturing complexity and costs.

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