VCR ENGINE 1

VARIABLE COMPRESSION RATIO ENGINE

PRESENTED BY

AJAY G.R.

S8/ME/Roll No.3

UKFCET

VCR ENGINE 2

COMPRESSION RATIO

UKFCET

VCR ENGINE 3

The static compression ratio of an internal-combustion engine is a value represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity. It is a fundamental specification for many common combustion engines.

In a piston engine, it is a ratio between the volume of the cylinder and combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke.

UKFCET

VCR ENGINE 4

VARIABLE COMPRESSION RATIO

Variable compression ratio is a technology to adjust the compression ratio of an internal combustion engine while the engine is in operation. This is done to increase the fuel efficiency while under varying loads. Higher loads require lower ratios to be more efficient and vice versa. Variable compression engines allow for the volume above the piston at Top dead centre to be changed. For automotive use this needs to be done dynamically in response to the load and driving demands.

UKFCET

VCR ENGINE 5

NISSAN VARIABLE COMPRESSION RATIO ENGINE

UKFCET

VCR ENGINE 6

Nissan broke new ground for gasoline engines at the 2016 Paris Motor Show when it unveiled the first production-intent variable-compression-ratio gasoline engine. The VC-Turbo, a 2.0-L inline four cylinder designed in house, features a novel crank train and control system that enables the effective compression ratio to be varied between 8:1 and 14:1, depending on load.

Making its debut under the automaker's Infiniti brand, the VC-Turbo (VC-T) has been designed to replace the company's 3.5-L V6, with a target output of 268 hp (200 kW) and 288 lb·ft (390 N·m). Infiniti has set a target for fuel consumption reduction of 27% compared with the V6. The VC-Turbo uses two fuel injection systems. The engine is being readied for series production in early 2018. The initial first vehicle application is the new QX50.

UKFCET

VCR ENGINE 7UKFCET

VCR ENGINE 8

VCR engines alter the compression ratio by rising or lowering the height of the piston at top dead centre, but the Infiniti engine achieves this in a unique way. Nissan engineers have adopted a multi-link system with an electric motor actuator, known as “Harmonic Drive Reduction Gear”

The Harmonic Drive is controlled by a dedicated ECU which gathers data from engine sensors to determine the compression ratio required for given driving (load) conditions.

UKFCET

VCR ENGINE 9

Main Parts

• Piston

• Upper-link

• Multi-link

• Crank shaft

• Lower-link

• Control shaft

• Actuator arm

• Harmonic Drive

UKFCET

VCR ENGINE 10UKFCET

VCR ENGINE 11

Working

• When a change in compression ratio is needed, the Harmonic Drive turns and moves the actuator arm.

• The actuator arm rotates the control shaft.

• as the control shaft rotates, it acts upon the lower link, which changes the angle of the multi-link.

• The multi-link adjust the height the piston can reach within the cylinder, thus changing the compression ratio.

UKFCET

VCR ENGINE 12

CASE STUDY

UKFCET

VCR ENGINE 13

INSPIRED BY HUMAN BODY

UKFCET

VCR ENGINE 14

CONCLUSION

• Allowing us to choose between both efficiency and power.

• The 197-hp Nissan VC-Turbo engine is designed to replace the company’s 3.5L V6, first in Infiniti QX50, while reducing weight by 25kg and targeting fuel consumption reductions of 27% vs V6.

UKFCET

VCR ENGINE 15

THANK YOU!!!UKFCET