Weldless Flange Connections
All cars, buses and trucks with combustion engines have a welded or cast manifold. The manifold is mounted on the engine and is the first part of the exhaust system. Exhaust fumes from all cylinders in the engine are brought together in the manifold. The fumes go through the manifold to the rest of the exhaust system with catalytic converter, muffler(s) and pipes. The welded manifold often consists of pipes and flanges, were the pipes are connected to the flanges with weld seams.
Is it possible to manufacture a manifold without welding the flange connections? This is the main question that will be treated and examined in this thesis work.
When construction and design work is performed the Ford I4 engine with present welded manifold will be used as reference. This means that the final prepared solution in this project fits the I4 engine but the solution must be general and compatible with all engines.
Objective and procedure
The goal with this part of the project is to find a principal solution for the flange connection. This means that a concept for the flange connection will be created.
First the product will be defined by a research of its task, surroundings, relation to man and economic conditions. Next a study over the present solutions background is done to get a hold of the product. Through this information criterions for the product were established with guidance from the supervisors at Faurecia . After this a search for solution concepts will take place. To choose the best solution concept evaluations are made in next step. Finally the chosen concept is presented.
Product definition contains following elements that will be treated and explained:
• Units that will be part of the final product.
• The main and part tasks for the product and possible relations between them.
• The relation between man and the product.
• The field range of application for the product.
• Economical conditions for the product.
The manifold is made for transporting exhaust fumes. The product is mounted on a combustion engine, between the engine and the exhaust system. Today the manifolds consist of a rear and front flange, pipes that connects the flanges and some kind of joining method where the pipes come together, see picture 2.1. The present solution for flange connection is for Faurecia to weld the pipes on the flange. The mission with this project is to find a new solution, for both the rear and front flange, without welding or casting the flange connection.
The main task for the manifold is to transport hot exhaust fumes from the engine to the exhaust system without leakage. Some manifolds have a part task with EGR- system (Exhaust Gas Recirculation) and in some cases a lambda probe will be mounted in the manifold. See figure 2.1 for task boxes.
The manifold will be placed between the engine and the exhaust system in a vehicle with combustion engine. The vehicles will be used all over the world were they can be driven. Products that are adjoining to the manifold are combustion engine, exhaust system and possible EGR- system, turbocharger and lambda probe. The manifold will be exposed of heat strain, -45 to 950ºC, corrosion from the exhaust fumes and water, external effects from static and dynamic loads from the engine and the exhaust system.