V6 Engine Report

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Abstract

In this project I decided to design a simple model of a V6 engine that would be used in a car. I used solidworks to build the engine. I was unable to print out the model due to time constraints. Furthermore, my engine did not function in the same manner as a normal V6 engine as the 3 pistons on each side moved together and not in different cycles. However, this model still is able to reveal how a cylinder engine functions on a basic level.

Introduction

The motivation behind this project was to reveal of the pistons of an engine drive the rotations of a wheels in a car. I wanted to expand my Solid Works skills and attempt to model a more complex object from scrap. The engine is complicated as it requires different parts to move together in harmony. The engine is one of the most basic objects that led to advances in technology and as such it is important to understand how objects like this work.

Background/Theory

The V6 cylinder engine is one of the most common car engines. Shaped like a V, the V6 engine has 6 pistons that turn a crankshaft which lead to the turning of the wheels of a car. The pistons move with a small explosion of fuel. This type of engine is more compact than other models. The V6 engine functions with four strokes from each piston: the intake, compression, power and exhaust. The intake begins as the piston moves downward in the cylinder, drawing in a mixture of fuel and air from the intake valve. The compression then begins as the piston moves upward in the cylinder, compressing the fuel. The power stroke occurs as the piston reaches the top of the cylinder and the spark plug fires, igniting the fuel and pushing the piston to the bottom of the cylinder. This is what provides the power for the causes crankshaft to rotate. The final stroke is the exhaust stoke where the piston moves back to the top of the cylinder and the exhaust value opens, releasing the exhaust material. This process is occurring for all 6 cylinders at different times, so the crankshaft is constantly being smoothly turned.


Completed Project Design

The design process of this engine began with the design of the individual parts through sketches. The parts where then contstucted individually in solidworks. Using an assembly, the parts were fit together to see if they run properly. When errors occurred in the assembly, the indivual parts were changed in order to meet the nessecary specifications for the assembly to work.

The design for the pistons was a circle with a diameter of 2 inches extruded 1 inch. Two rectangular 1 in. X .21 in. prisims were then extruded .25 inches above each other from the bottom of the cylinder. They were the connected with a cylinder with a diameter of .25 in. This cylinder is the means for connecting the piston to the piston connector which will then attact to the crankshaft.

Piston.jpg

The piston connector was a simple recatangular shape will two circles on each end. The connector was 2 inches from the center of either circle and extruded .1 inch. Two smaller circles with diameter of .25 inches were then drilled into the center of the larger circles.

Piston connector.jpg

The design of the engine shell first began by constructing a 10x6 inch rectangular frame extruded .1 inch with each side having a thickness of .1 inch. On the front end of the 6 in. side of the frame, a frame of a tiangle with the hegit of 4 in. with side of .1 thcikness extruded .1 inch was contsructed. This frame was then extruded to the back of the rectangle. From these new surfaces, two rectangular prisims 9x4 inches were extruded. In each of these prisims, three circles with 2 inch diameter were drilled all the way through. These would function as the cylinders of the engine. The cylinders centers were each 4 inchs away from each other, the outside cylinders being .5 in. away from the edeges of the prisim. Each of the four sides of the original frame were extruded down 5 inches. A .25 inch hole was then drilled in the center of the front sides of the engine 2 inches down.

Engine shell.jpg

A crank used to turn the crankshaft for modeling purposes was the contructed by first extduding a circle of diameter .5 inches by 2 inches. This was then connected to a straight slot with a diameter of .5 inches, length 1.5 inches, extruded .2 inches. On the opposite side of the slot, another cylinder with a diameter of .25 inches and height 1 inch was constructed.

Crank.jpg

The final part was the crankshaft which was designed differently from a normal crankshaft. In a normal V6 engine, the crankshaft would be designed so that each of the 6 pistons moved seperatly. However, because this was only a simple V6 engine model, the cranksahft was designed so all three pistons on each side would move together, giving the engine the functionality of only two cylinders in relaity. The crankshaft began with sketching a circle with a diameter of 3 inches. Two arcs were then drawn inside the circle in order to trim some of the circle away giving in a curved T shape. This sketch was then extruded .1 inches. A cricle of .5 inch diameter was drilled from in the center of this 3-d sketch. A new part was made which was simply a 9.5 inch long cylinder with a diameter of .25 inches. In an assemply, two of the curved T shapes were connected togetther by the cylinder.

Crankshaft.jpg

Once all of these parts were correctly constructed the were put together in an assembly. 6 pistons were mated with piston connectors trough one of the holes on the piston connectors to the rod on each of the pistons. These full pistons were then mated to each of the cylinders in the engine shell. The crankshaft was mated with the crank through the hole in one of the front ends of the engine. Each remaining hole on the piston connectors was then mated to the cylinder of the crankshaft. In order to make the final animation, a motor was places on the crank so that it would turn, causing the mostion of the pistons, although in reality, the pistons would be moving the crank.

Engine.jpg

File:EngineFinal.avi

Results

Overall my goals were somewhat achieved as I was able to construct a very simple model of a V6 engine in solidworks. However, I was unable to make the crankshaft correctly and as such the pistons moved three at a time instead of all at different times. This is a key part of a V6 engine. Yet, the pistons were still able to move and represent the way in which an engine works.

In order to more fully achieve my goals, I could have desinged a correct cank shaft which would allow the pistons to move seperately. My engine as is would not be very functional. Furthermore, because my model is so simple, it does represent all of the different strokes of a piston engine. There are no spark plugs or intake or exhaust valves.

Discussion and Conclusion

Overall, my design process worked fairly well. I was able to design parts and have the put together in an assembly and then go back and chagne them if nessesary. The most difficult and time consuming aspect was figuring out the correct dimensions for each part so that the pistons would go up and down as the were supposed to.

The biggest issue I had wa designing the crankshaft. Although I was able to find many pictures of crankshafts on the internet and a few in soldiworks models, I was still unable to figure out how to correctly build one. This was partly due to my inexperience with solidworks. In order to have built a better crankshaft I would need to spend more time on the blueprint sketchs in order to get the pieces to fit together correctly.

In the end, my model is still able to eximply the basic motions of a cylinder engine, although it could have been better designed.