In this blog post, we will look at the history and development of cars, analyze how internal combustion engines generate power, and examine the impact cars have had on modern life.
Mr. K, a student at Seoul National University, wakes up early every morning and takes his father’s car to Dongcheon Station. He then takes the Shinbundang Line to Gangnam Station, transfers to Line 2, and arrives at Seoul National University Station, where he takes a shuttle bus to campus. Like Mr. K, everyone in modern society relies on transportation such as cars, subways, and buses in their daily lives. Among these modes of transportation, the most common is probably the car—if you don’t believe me, just look outside! How can cars be distinguished from other modes of transportation? How did cars come to be? How do cars function as a mode of transportation? Let’s find out.
To distinguish cars from other modes of transportation, let’s first define what a mode of transportation is. When we think of buses, airplanes, and ships, we think of transportation that can move people to their desired destinations and transport cargo to where it is needed. Conversely, any device that can move people and cargo can be considered a means of transportation. Cars, one such means of transportation, function only on land. However, the fact that they function on land alone is not enough to distinguish cars from subways. What can distinguish between the two? Generally, subways are much larger than cars, but this cannot be used as a criterion. This is because the standard for how large something must be is vague, and it is possible to actually build a car as large as a subway. “Operating only underground” is also not an appropriate criterion, as subways have sections that run above ground, and cars can also travel underground. Considering that subways are powered by high-voltage lines, we could think of “powered by electricity” as a criterion, but this criterion is not appropriate due to the existence of electric cars. Instead, let’s pay attention to the fact that subways can only run where there are high-voltage lines. Then we can see that subways only move where there are railroad tracks. If they satisfy the condition of “traveling only on a fixed route,” they can be classified as subways, and if not, they can be classified as cars. In short, cars are a means of transportation that move only on the ground and can travel freely anywhere on the ground.
Cars did not just fall from the sky one day. Transporting goods and people has always been important. As a result, the wheel was invented about 6,000 years ago. The invention of the wheel made these tasks easier than before, but they still required a lot of labor. This inconvenience continued until Watt improved the steam engine in 1765. After the improvement of the steam engine, in 1769, French military engineer Nicolas-Joseph Cugnot developed the first three-wheeled steam tractor for the purpose of pulling carriages. With this, cars that generated their own power began to appear in earnest. The first cars, steam cars, had large and heavy boilers and took a long time to gain power. These problems were solved by changing the method of obtaining power. The automobiles that appeared during this process were electric cars and gasoline cars. You may wonder, “Why electric cars?” Surprisingly, electric cars first appeared in the mid-19th century. Gasoline cars began with the development of the internal combustion engine, a device that burns fuel inside to generate power, by Renault in 1860. After Otto and Daimler invented practical internal combustion engines, gasoline-powered cars began to be manufactured in earnest. Interestingly, gasoline-powered cars had the lowest market share among the three types of cars at the time. This was because early gasoline-powered cars had many complex parts, which made them prone to breakdowns and difficult to maintain. However, after repeated improvements and the introduction of the conveyor belt by Ford in 1913, which enabled mass production of automobiles, gasoline-powered cars came to dominate the market. Most of the cars today are gasoline-powered cars, which won the three-way battle. However, none of the three types of cars mentioned above were able to realize the concept of “people-less transportation,” which was the background for the emergence of automobiles.
To achieve this, global companies such as Google and Tesla, a leading electric vehicle manufacturer, are currently researching driverless cars. There have been many developments in the evolution of the automobile as an essential means of transportation in modern society. In the early 20th century, automobiles were mainly the preserve of the upper classes, but with the development of mass production technology, prices fell and they became popular. In particular, Henry Ford’s Model T played an important role in the popularization of automobiles. The popularization of automobiles had a major impact on social structures and urban planning. With the expansion of roads and highways and the development of suburban areas, automobiles gave people freedom of movement. In addition, the development of the automobile industry became an important pillar of economic growth and created numerous jobs. Automobiles have gone beyond being a mere means of transportation and have become deeply rooted in the economy and culture of modern society. How do today’s mainstream gasoline-powered automobiles obtain the power to transport people and cargo?
As mentioned earlier, they do so with the help of internal combustion engines. The principle behind how internal combustion engines obtain power from oil is basically simple. They obtain power by converting the energy obtained from the internal explosion of oil into kinetic energy. To understand this process in more detail, let’s take a look at the four-stroke cycle engine, an internal combustion engine developed independently by Otto and Daimler.
Let’s start by understanding what a four-stroke cycle engine is. A stroke refers to the distance traveled by the piston inside the cylinder. A cycle refers to a repetition or rotation. Therefore, a four-stroke cycle engine is a power generation device in which the four movements of the piston constitute one cycle. In line with this interpretation, a four-stroke cycle engine generates power through four stages: intake, compression, combustion, and exhaust.
In the intake stroke, the intake valve opens and the exhaust valve closes. In this state, as the piston moves down, the air pressure inside the cylinder becomes lower than the external air pressure, and this pressure difference causes air or a mixture of air and fuel to enter the cylinder. This is similar to pulling back the piston without blocking the hole in a syringe.
During the compression stroke, both the intake and exhaust valves are closed and the piston rises. As the piston rises, the pressure and temperature inside the cylinder naturally increase, and the density increases. Before the piston reaches its highest point, an explosion occurs, and this process varies depending on what was put into the cylinder during the intake stroke. If only air is introduced, fuel is sprayed into the cylinder as tiny particles like mist during this process. If the fuel is diesel, the spray causes an explosion, but if it is not, the process of introducing a mixture of air and fuel follows. When a mixture of air and fuel is introduced, a small flame is lit to cause an explosion. This is achieved by a device called a spark plug mounted on top of the cylinder. This process is similar to blocking the hole of a syringe filled with air and pressing it down with a piston. In the
explosion stroke, the piston is pushed down by the high pressure of the gas combusted in the compression stroke. The work obtained at this time is greater than that used in the compression stroke. In other words, it is in this process that the internal combustion engine actually obtains its power. As the piston moves down, the pressure of the gas inside the cylinder decreases, and the gas spreads inside the cylinder. Before the piston reaches its lowest point, the exhaust valve opens to allow the gas to escape. This is similar to the situation when the hole that was blocked is suddenly opened, causing air to suddenly escape from the syringe.
In the exhaust stroke, the piston rises with the exhaust valve open. As the piston rises, the pressure of the gas inside the cylinder becomes greater than the external atmospheric pressure, causing the gas to escape. When the piston reaches its highest point, the process repeats from the intake stroke, and the four-stroke cycle engine gains power.
Now we have learned about automobiles, one of the most common means of transportation around us. Automobiles have become a tool that modern people use every day without fail. However, we have become so accustomed to them that we do not understand exactly what they are. In order to understand what automobiles are, we first considered the common characteristics that all means of transportation must have, and then analyzed the differences between automobiles and other means of transportation that move only on the ground, such as subways.
As a result, we learned that automobiles are devices that transport people and cargo along unspecified routes. We then examined the historical context in which automobiles appeared. Next, we looked at the process by which gasoline-powered automobiles obtain power from internal combustion engines, using the four-stroke cycle engine as an example. Automobiles are deeply rooted in modern life, and their importance will continue in the future.
With advances in technology, automobiles are becoming more efficient and environmentally friendly. With the introduction of innovative technologies such as electric vehicles, hydrogen vehicles, and autonomous vehicles, the automotive industry is entering a new era. These changes are fundamentally changing the way we travel and raising expectations for the future of transportation. Ultimately, automobiles will continue to evolve beyond a simple means of transportation to become an important factor in enriching human life.
