Funtional Diagram/Outline of Engine Functions
Primary Function: Convert Chemical Energy to Mechanical Energy
The main function of the CBR 600 engine is to convert chemical energy in gasoline to usable mechanical energy. This is accomplished through different systems within the engine and their respective subsystems. The mechanical energy output of the engine is a rotating output shaft.
I. User Input
The operator has the ability to control the inputs and outputs on the engine. This includes the ability to start and stop the engine as well as control the throttle position and thus the torque and rotation speed of the engine.
The user adjusts the flow of fuel to the engine with the right side handle that is connected throttle with a cable. Manipulating this control allows the user to control the power output of the engine. Twisting the throttle opens up the throttle valves in each of the carburetors allowing additional gasoline and air to enter the engines expansion chamber. This increase in gasoline and air allows the user to control the amount of power that the engine creates in a controlled manner.
B. Clutch and Gear Selection The user disengages the clutch via a lever on the handlebars which is connected by a cable to the clutch assembly. Disengaging the clutch (squeezing the clutch lever) separates the transmission from the engine, making the engine spin independently from the transmission. Letting go of the clutch lever engages the clutch. This couples the engine and transmission together and allows the engines energy to be manipulated in the transmission. In order to change gears the user of the motorcycle must disengage the clutch so that the force of the engine is not spinning the gears of the transmission before changing gears with the foot lever shifter.
The user starts the engine with a push button that sends an electrical signal to the starter motor. The starter motor sends a force through the crankshaft to allow the engine to begin operation. This initial force starts the cycle of combustion which allows the engine to run on its own.
Air and gas are brought into the system.
A. Air Intake
Air is drawn into the air box through a filter and which is then passed on to the four carburetors to be mixed with gasoline which will be used to produce power.
B. Fuel Intake
Fuel from the gas tank is drawn through the fuel lines to the carburetors and is mixed with air to be ignited and used as power in the engine.
III. Energy Conversion
This is the largest sub-function of the engine and fulfills the main purpose of the system. Electrical and chemical energy are converted into rotational mechanical energy through combustion within the engine. This is then sent to the transmission where the energy can be efficiently used.
The ignition signal causes electrical energy to flow to the starter motor which provides the initial rotational energy to the crank shaft until the combustion powers the energy. Until the engine is running on its own energy is effectively flowing backwards through the engine.
Air and fuel mix in the four separate carburetors. This mixture is then released into the combustion chambers. A butterfly valve which is attached to the throttle cable controls the amount of air/fuel that is allowed into the combustion chamber with each pass of the piston. The angle of this valve either inhibits or allows the air/fuel mixture into the engine. Chemical
The fuel air mixture that has been released into the combustion chambers is then compressed by the pistons. The spark plugs then ignite the mixture and thereby greatly increase the pressure within the combustion chamber.
D. Mechanical Energy Created
The downward force of combustion on the pistons rotates the crankshaft. The one dimensional reciprocating motion of the piston is translated to the rotation of the crankshaft by the piston-crankshaft linkage.
Rotational energy created in the engine block is transferred through the crank shaft to the transmission. In the transmission, the crankshaft torque and angular speed is manipulated.
The operation of the clutch lever by the user engages and disengages the clutch. When disengaged, the operator is free to shift through the different gears in the transmission. When engaged, rotational energy is transferred through the clutch assembly to the gears.
The different gears ratios within the transmission change the torque that is created by the rotation of the crankshaft. This energy is transmitted though different gears and to the drive shaft which is then used to do work.
The byproducts of combustion are expelled from the combustion chamber and transferred out of the system through the exhaust pipes. This includes waste gasses and heat. Heat is also conducted out of the system and into the surrounding through all components of the system. This includes heat created from combustion and friction.
A. Gas Expulsion
Waste gasses from the combustion process are expelled through the exhaust system.
B. Heat Expulsion
Heat is lost through conduction across the exterior system boundaries as well as through the exhaust pipes.
VI. Lubrication and Cooling
A. Oil Circulation
Oil is circulated throughout the engine block in order to minimize friction between all moving parts. When the engine is running, the motion of all moving parts disperses the oil from the oil pan to all surfaces within the engine. An oil pump, whose energy is derived from the rotational energy of the crankshaft, pushes oil through a filter in the bottom of the oil pan in order to remove damaging particulates from the engine.
B. Antifreeze/Coolant Circulation
A liquid with a high boiling point and low freezing temperature is circulated through canals in the engine block to remove heat. This dissipation of heat prevents the engine fro overheating and keeps the components of the engine within their optimal temperature range for operation. The antifreeze/coolant flows through the engine in a loop. The solution gains heat energy from within the engine which is radiated away in a radiator with a large surface area and high air flow.
Outline With Corresponding Subsystem Diagrams
Order of Subsystems
The operation of the CBR 600 engine is a complex process that requires many subsystems to work in unison in order for the end result of rotational energy to be achieved. The subsystems can roughly be simplified into a loop. the intake of air and gasoline into the engine begins the process. These two components are the fuel for the engine, they are mixed in the carburetors and released into the combustion chamber of the engine to be ignited and the energy from this chemical change is used to turn the crankshaft of the engine and in turn the transmission of the engine, which leads to the output shaft which can be used to perform work to move the motorcycle for which it is attached. while this may seem like a small loop various subsystems keep everything moving smoothly along the way. The cooling system is constantly circulating coolant throughout canals within the engine block to radiate away excessive heat, and a lubrication system is keeping the moving parts inside of the engine all running smoothly and with as little friction as possible. A valve system allows the air/fuel mixture into the expansion chamber at the right time and also allows the ignited mixture to expand until the pistons can no longer gain energy from the exothermic reaction of the air/fuel mixture. At this point the exhaust valves open and the waste gasses present in the expansion chamber are then allowed to flow out of the expansion chamber into the atmosphere. The momentum gained by the engine then allows the air/fuel mixture to be again pulled into the expansion chamber and the whole process repeats itself and the engine runs as it should.
Global, Societal, Economic and Environmental Impact on Design
Global, societal, economic and environmental concerns have only a small influence on the arrangement of the components in the engine. most of the design of the engine is related to what makes the engine work best in its end use. The layout of the engine is designed to be as efficient as possible. Certain components are in the engine the way they are in order to be operated by a human, such as the location of the shifter lever and the respective components that need to be placed in order for the shifter to be located near the foot of the operator. Economic and environmental concerns were in mind when the engine was designed. The efficiency of the engine and the pollutants that it emits were minimized by the engineers designing the engine. A balance of power, efficiency and reliability is apparent in the design of the engine. Focusing too much on one of these three categories would compromise the other two. For example, a high horsepower engine of the same size and type as ours would be running at much stricter tolerances, and would need more maintenance, and would use much more gasoline as a less powerful but more efficient engine. Each of these three engine characteristics effect the other