Design and operation of a new multifunctional wear apparatus for engine valve train components

Abstract

The increasingly strict emission regulations in combustion engines are raising high requirements for the engine valve train system. In this paper, a novel multifunctional wear apparatus is designed to study the performance of engine valve train components. The apparatus employs a mechanical loading system, which consists of a special eccentric wheel and disc springs that apply the combustion loads, and the contact configurations and loading conditions of valve train components are simulated. It has three test functions for different components through specifically designed fixtures. The first function aims to evaluate the interaction between the valve seating face and the seat insert at high temperatures and loads. The second function is used to study the friction and wear properties of the valve stem and the valve guide. The third function is designed to evaluate the performance of the valve seals. At last, a verification test was carried out by the proposed experimental method. A pair of new exhaust valve and seat insert is tested for the performance evaluation of the first function. The wear mechanisms acting on the pairs interface are shown to be a combination of oxidative wear, adhesive wear, as well as fatigue flaking.

The wear and fatigue behaviours of hollow head & sodium filled engine valve

“…The method has seven steps, as follows: (1) solid bar workblank preparation; (2) upsetting; (3) punching for valve hollow head; (4) valve hollow stem drilling; (5) friction welding sealing at valve hollow head; (6) sodium filling and friction welding sealing at valve hollow stem; (7) seating face hardfacing with Stellite alloy. (1) ( The fifth step is the critical step, where the valve hollow head is sealed with the disk conical surface through friction welding. Selected images of the process are recorded in Fig.…”

“…The valvetrain is one of the most important systems in an internal combustion engine (ICE), as it controls the gas flow and the timing of the engine. The valve and valve seat insert are critical components of the valve train, because they control the entry of air (and in some designs, fuel), the output of exhaust gas, and provide sealing during the compression and combustion processes [1]. One of the primary targets in the combustion engine industry is the increase of the engine power to size ratio.…”

“…M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT12 / 34 developed for this purpose and presented inFig.6 (a). Its detailed information can be seen in the work of Lai et al[1]. The test schematic is illustrated inFig.6 (b), the valve and seat insert geometry are presented inFig.6 (c).…”

Optimization of Friction Welding Process Parameters for 42Cr9Si2 Hollow Head and Sodium Filled Engine Valve and Valve Performance Evaluation

“…During the durability tests, the determined heat and load can be applied to the central area of the hollow valve head. The apparatus is more thoroughly described in previous work [24].…”

Effect of welding conditions on erosive wear of hard-faced Co-based alloy layer

“…These alloys are frequently used in weld hard-facing of various engineering components such as gate valves of the petroleum industry, valve seat, etc. 7,8 Material is removed from the target surface by the impact of a stream of particles during erosion. 7 This is a special degradation mode that affects the longevity of parts exposed to aggressive erosive environments in many industries including aerospace, marine, mining, wind energy, oil and gas, [9][10][11] etc.…”