Subject internal combustion engine report variable compression ration (vcr

knowledge thereby contributing to improving the performance of cars and saving fuel and energy - the world''''s finite resource and is gradually being depleted.• Variable Compression Ratio

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SUBJECT: INTERNAL COMBUSTION ENGINE REPORT: VARIABLE COMPRESSION RATION (VCR)

LECTURE: Assoc.Prof LY VINH DAT

STUDENT NAME: MAI HOANG MINH HUY

ID: 21145012

CLASS: ICEP330330E_22_2_02FIE

5 Advantages and Disadvantages of VCR 18

1 Reason For Choosing This Topic

• The introduction of the internal combustion engine marked an important turning point in the history of world transportation Since then, the

corporation has been gradually mechanized, reducing grueling labor jobs that previously could have used only human, horse or animal power instead Over a long period of development, today's engines have made great progress and the contemporary engine development trend also has many top options such as: achieving huge power with low fuel consumption Low data, high economy, and especially toxicity in the exhaust must meet strict requirements These achievements are achieved through equipping the microcontroller to control the techniques Therefore, the motor is

regenerated from mechanical control to electronic control.

• The world entered a new century, the century of advanced technology led to the development of the transportation industry and the production of means

of transport Besides the positive sides, there are still many negative things happening and the world is facing, which is the serious problem of emissions and environmental pollution in many big cities and developing countries It directly affects the living environment and human health and is also the cause of the current greenhouse gas and ice melting at the two poles In addition, limited resources of petroleum as well as increasingly strict emission standards in many advanced countries force scientists to research

to come up with optimal measures to solve these problems they are constantly researching to find and come up with measures to optimize performance as well as save energy in cars The automobile market creates many types with many different uses, and one of the measures applied to

cars today is the technology of Variable Compression Ratio (VCR) VCR

is one of the solutions to increase engine power, reduce fuel consumption by improving combustion efficiency, and reducing harmful emissions This is achieved through the ability to dynamically change the compression ratio to change the engine's combustion chamber volume according to the vehicle's operating conditions thereby limiting environmental pollution and saving energy as well as increasing efficiency in cars in particular and means of transport in general.

• The world is in the era of digital technology 4.0 Technology and science are developing day by day, demanding students or future engineers must have the equipment and knowledge to meet the demands of today's fiercely

competitive jobs Self-study in a university environment is extremely necessary for every student The study of specialized problems as well as solving real-life situations is one of the teaching methods that schools are advocating towards Thereby promoting the role of learners, who acquire knowledge from lecturers with the task of guiding students in the right direction Learning from developed countries in the world, self-study method combined with practical practice will help students develop comprehensively and not be left behind in a development phase every second Especially in the automotive engineering industry, analysis and research is a very practical need In addition to changing learning models and learning technologies, the application of vivid images and experiments with models is also encouraged Besides, the variety of reference materials and textbooks will also make the learning and self-study process easier Moreover, the research on Variable Compresstion Ratio (VCR) topic by scientists is to help students have a more specific view of the compression ratio and its importance, thereby helping students consolidate their

background knowledge as well as improve their understanding of the subject knowledge thereby contributing to improving the performance of cars and saving fuel and energy - the world's finite resource and is gradually being depleted.

• Variable Compression Ratio (VCR) is a technology that adjusts the

compression ratio of an internal combustion engine while the engine is running This technology helps to optimize performance and save energy in the engine and meet the load and driving needs of different vehicles The structural and operational features will be presented in the following section

2 History of VCR

• The Variable Compression Ratio (VCR) is an important component

in an internal combustion engine It is used to increase fuel efficiency and reduce emissions by adjusting the engine's

compression ratio

• in the 1920s:

Harry Ricardo built the first known variable compression ratio engine as a test engine in the 1920s to study knock in aircraft engines Variable compression ratio was achieved by

raising or lowering the cylinder and cylinder head of the engine relative to the crankshaft This work led to the development of the octane rating system that is still in use today Variable compression ratio engines have subsequently been investigated for decades, but none have been

commercially produced due to mechanical complexity, difficulty of control, and cost This work led him devising the octane rating system and is still in use today

corporations and automakers such as Toyota, Nissan and Mitsubishi have started using this VCR technology on some

of their models to introduce to their customers

• The 21 century: st

New technologies such as hybrid and low-capacity gasoline engines continue to be the premise and stepping stone to promote the development of VCR European automakers like Audi, BMW, Mercedes-Benz or across the continent we have Japanese cars like Civc, Mazda competing to develop advanced VCR systems and apply this technology and launch them with customers on their car models

• Recently, VCR is by far one of the most advanced engine

technologies in the world, widely used in the automotive industry and internal combustion engines in both luxury car manufacturers and popular car manufacturers common in developing cities New technologies such as electric

propulsion and hydrogen fuel engines are also being developed to increase efficiency and reduce emissions, but the importance of VCR technology is undeniably an

important part of it of internal combustion engine

technology

3 Construction of Variable Compression Ratio (VCR)

the combustion process' efficiency; the higher the compression ratio, the more fully the combustion process occurs For gasoline engines, the compression ratio cannot be continuously increased because, at high ratios, the gasoline and fuel mixture may

spontaneously ignite for spark plugs and "knock" when it enters the combustion chamber Engine detonation reduces engine power and could harm the engine

Daimler Benz VCR Piston

Technical method of application VCR technology in piston engines and their technical and

operational features.

• In 2018 Infiniti began production of their variable compression

turbo engine, which uses a mechanical linkage to achieve the

variability It was installed in their QX50 SUV The engine can

produce any compression ratio from 8:1 to 14:1 The highest

torque is achieved at 8:1, giving high acceleration, while the best gas mileage (fuel efficiency) is achieved at 14:1 The electronic

engine controller responds to the pressure on the gas pedal, in time, altering the compression ratio seamlessly Although this

real-engine has a displacement of 2.0 L, and is an inline-four real-engine, it does not use balance shafts to eliminate the secondary vibrations It

is inherently balanced by the mechanical linkage

• With VCR technology, the part is designed in detail to ensure the

consistency and smoothness of the technology These are main

• Eccentric big end rod bearing

• Eccentric crankshaft bearing

• Eccentric piston pin

• Multi-link rod-crank

VCR Engine Program

Diagram of VCR Nissan 2009

MEC-5 VCR engine

- Nissan's new variable compression ratio engine, also known as the VC Turbo, was unveiled at the 2016 Paris Motor Show and temporarily halts the company's transition to an all-electric car future The 2.0-L VC Turbo makes its premiere in the all-new

2019 Infiniti QX50 compact luxury SUV, fully productionized

as the KR20DDET The 2019 Nissan Altima, its second

announced application, will significantly increase its production scale

- As detailed in SAE Technical Paper 2018-01-0371,

“Development of a New 2L Gasoline VC-Turbo Engine with the

World’s First Variable Compression Ratio Technology The

VC Turbo can infinitely vary its piston stroke and effective compression ratio between 8:1 and 14:1 The low-compression mode is for high power demand and high-road-load conditions and the high-compression mode for cruising and light loads

- The net effect is an engine with the power of the 3.5L V-6 it replaces, but with a 27% gain in fuel efficiency, all in a

responsive, high-performance package In our testing, an engine

rated at 24/30 mpg (9.8-7.8 L/100 km) city/highway produced 25-26 mpg (9.0-8.7 L/100 km) in everyday driving.

- In 100+ miles (161 km) of L.A metropolitan driving, the

3952-lb (1793-kg) QX50 delivered 24 mpg, mostly operating in the high-load/low-compression mode So, the real question: How much of the QX50’s fuel-economy improvement is due to downsizing to a 2.0-L 4-cylinder turbo

- Challenges in optimizing the VC mechanism included machining the central cantilever/actuators that vary the piston stroke, Kiga said Tolerances are critical, he continued, and that’s one of the reasons the VC Turbo 4-cylinder is assembled

at the same Yokohama plant that makes the high-performance Nissan GT-R V6

b Toyota VCR engine

- Toyota's idea would use a variable length connecting rod to alter the compression ratio Toyota claims that their recently patented concept reduces production costs and raises the dependability of variable length connecting rods

- Toyota has patented an idea for a variable compression engine While the result is similar to what Infiniti achieves with its Variable Compression-Turbocharged powerplant, this concept works in a completely different way

- Toyota's design mounts the top of a regular connecting rod to two hydraulically operated pistons A switching pin and check valve would be able to change which of these pistons

compresses by modifying the oil pressure By doing this, the

connecting rod's length alternates between a high-compression setting and a low-compression one.

- However, it was anticipated that Nissan's design would function best with a four-cylinder in order to save expenses and engine complexity Toyota has not stated if this design may be

employed in a four-cylinder, V6, or V8 engine However, it is unclear whether Toyota is genuinely considering developing such an engine or if it is merely interested in researching the technology as it seeks to improve fuel efficiency with

conventional internal combustion engine automobiles

- These devices' too-limited adjustment range for compression ratios is one of their drawbacks For the 2.5L Toyota TNGA engine, for instance, a VCR travel distance of 8.0 mm would be required to change the compression ratio from 16.5:1 to 8.0:1

compression ratio from 14:1 to 8.0:1) It is believed that only about half of this travel distance can be provided by adjustable piston and connecting rod devices Finding a tiny VCR travel range has been a development goal for a number of automobile

and R&D companies (plus other engine settings) that will deliver between 50% and 60% of the advantages of a full range system The goal of the alternative development strategy is to locate conditions that add a 10% benefit to the full range VCR mechanism.

- A second limitation with these mechanisms is increased mass

An engine development objective is to minimize piston and connecting rod mass

- Some of these mechanisms have only two settings, high and low compression ratio A fully variable compression ratio

adjustment capability is desirable

will begin to become a a technical standard for automotive piston engines in the near future

• The developed design of the VCR engine opens up new research and development opportunities that were not available before It concerns mainly to new directions of improvement of enginev working processes and exploitation possibilities of internal combustion engines, that is, research on advanced, low-

temperature combustion processes or research on the unification and flexible use of various fuels for transportation, including alternative fuels of different reactivities

• From the foregoing, it can be seen that the development of VCR technology in automobiles today has a lot to do with the growing automotive industry, as well as requiring emission standards from different countries in the context that the environment is getting worse due to climate change and a large part of the cause is from exhaust gases from current means of transport

• This study examines the geometric methods and solutions employed to obtain VCR, takes into account the findings of other studies, and predicts what, if any, advantages a VCR would bring

to the current engine design

1648, 2005.

5.Schwaderlapp M., Habermann K., Yapici K Variable compression ratio - a design solution for fuel economy concepts SAE paper 2002– 01 -1103, 2002.

6.https://www.nissanglobal.com/EN/INNOVATION/TECHNOLOGY/ARCHIVE/ VC_TURBO_ENGINE/

exactly-how-infinitis-variable-compression-engine-works-and-why/

7.https://www.roadandtrack.com/new-cars/car-technology/a15942295/heres-8 patent/

https://www.motor1.com/news/178652/toyota-variable-compression-engine-9 https://en.wikipedia.org/wiki/Variable_compression_ratio

10 https://www.youtube.com/watch?v=d3md1EqL1h4