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In this paper it is presented a mechanical study made on prototype parts created from aluminium and thermal conductive plastic. The scope is to replace full metal parts used for cooling electronic control unit in automotive industry and save costs. We used aluminium plates and thermal conductive plastic parts for this study. The permanent bonding of two materials, without any glue or additional additives, can be obtained by applying heat on an aluminium plate until around 300 degrees Celsius and pressing the plate on a thermal conductive plastic part. This solution has the following advantages: it can be used to cool local spots and bring around 30% savings by replacing full aluminium housings with parts built from plastic and local aluminium plates. Where the heat dissipation cannot be made without forced air convection, a solution is to combine plastic housing with an aluminium heat sink. The assembly solution is innovative. Our tests prove the efficiency of this solution to be around 20% lower than a full aluminium housing, from cooling effect point of view.

In this paper we will present a mechanical study made on the design of thermal conductive plastic parts. Out of our study derived new design rules that are useful for mechanical design engineers that have to create parts built from this type of materials. We used Catia V6 software for modelling the parts and ANSYS Moldflow software to simulate the behaviour of real components. The solutions resulted from our trials are improving the quality of the parts built from thermal conductive plastics. The test and simulation results lead us to new rules for designing screw domes and rivets for thermal conductive plastic parts and reducing warpage effect with 75% on this kind of parts.

High pressure injection pumps use removable assemblies with screws. They allow the subsequent assembly and disassembly, without destroying the components and the entire assembly, whenever is necessary. Our paper is an experimental analysis highlighting the influence of tightening parameters on components deformations. We perform the study using controller, Janome screwdriver, ZEISS measurement system and SEM (Scanning Electron Microscope) used in the metallographic analysis. Various torques applied on the screws give us results that show the interactions and their impact on the pumps components, producing deformation on the screws, gaskets and even front plate. A trial was done to establish the upper limit for the torque of the screws. After applying several tightening’s at different values, we conclude that the optimal upper limit for screws tightening between front plate and housing is 45 Nm. Applying a torque bigger than 50 Nm, the screws are destroyed, shear. This can generate numerous defects on the sealing gasket area and on the front plate in the screws holes area. The circularity of the front plate is impacted by the thickness of the wall and the inner / outer diameters.

All plastic parts suffer deformations during cooling of the material after the injection process. The effect is called warpage. This problem is known by all mechanical design engineers and in development, each engineer tries to compensate this warpage using different design solutions. In this article we are analyzing one important solution for warpage compensation and we will present our results and the optimization steps that led us to the results. The solution is a step for a vertical wall of the housings. For this step we analyzed different dimensions and combinations to provide the best solution.

The sealing of the high-pressure pump is carried out by means of a seal between the pump drive shaft and the front plate to keep the fuel inside them. The literature presents numerous studies carried out on how these seals last in time and on their composition. Due to the fact that during assembly or during the mounting of the pump on the engine may occur accidental defects on the sealing area, our interest in this paper is to investigate their impact on pump operation. The damages were explored on a test bench a certain number of kilometres and later analysed their impact on the pump using an ultraviolet chamber in a dark room. The experimental analyses were carried out using the EvoCam optical microscope, but also with the help of computer tomography procedure.

The high-pressure pump is a component of the automotive common-rail system and has as main assemblies: housing, driveshaft, gaskets and front plate. Literature presents analyses of the threaded fastening assemblies, especially for those with the critical joints with screws, those involving torque and angle. The assembly process that we have studied performs the sealing of the components with the gasket through the screws, thus preventing the fuel from leaking from the pump. Our paper presents an analysis of the influence of the tightening process with screws of the housing, gasket and front plate. The experiment was conducted using the Zeiss measuring system and the screwdriver Janome. The tests analysis demonstrates that screwing process can influence the distortion.

The EN62368 norm is a European standard that specifies the safety requirements and the testing procedures that all audio/video, information and communication technology equipment need to fulfil. In order to fulfil this standard, all mechanical engineers should change the way of designing the parts and respect new rules that can increase the cost of production for all plastic parts. These changes will lead to a higher tool complexity and high material costs. Plastic material suppliers are starting to change their focus and develop new V0 materials with better and eco-friendly properties according to the market needs. Plastic materials with flame retardant compounds (FR/V0 – classification according UL94) need to pass all flammability requirements and tests and according to environment regulations, the plastic materials that are halogen free are more are more requested. In general, halogen free systems produce less smoke and less toxic components in smoke. Benefits of halogen free V0 materials is a better flame-retardant property, low smoke toxicity, low smoke obscurity and no corrosive gases. The tool complexity will increase because we must reduce, even avoid, the openings in all plastic parts because they will allow oxygen to get inside the ECUs and oxygen is maintaining the flame, making a potential ignition source to increase her breadth. Reducing the openings in a plastic part, will lead to adding sliders inside of the mould and sliders involves higher costs. Although, depending on the current that goes through the ECU, we can recommend you some design modifications that will save money and time for your project.