Currently, the common-rail injection system is composed from a high-pressure pump, injectors, an electronic control unit and a common rail. Over time, the common-rail system has been simplified and optimized, but it remains that the high-pressure pump can still be affected by distortion which occurs during the pump assembly process and in turn has an effect in mounting the pump to the engine. The main assemblies of the diesel pump are the front plate, housing, driveshaft and hydraulic head. Our paper presents a solution for minimizing the distortion and also any external leaks that may occur due to a change in design of the sealing gasket between the body and front plate. This modification realizes the connection interface with the engine block and facilitates the pump mounting. The tests analysis is performed on high pressure pumps to determine where and when the distortion occurs.

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 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.

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 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.