The term “throttle” refers to a mechanism that manages fluid flow by constriction or obstruction. It is widely used in various types of engines to control power and speed. Below is a comprehensive overview of the throttle, covering different aspects and applications.
Internal Combustion Engines
Function
In internal combustion engines, the throttle regulates the amount of air or fuel-air mixture entering the engine, thereby controlling the engine’s power output. The control mechanism used by the driver is often called the throttle, accelerator, or gas pedal.
Types of Throttles
- Gasoline Engines: Typically use a butterfly valve to regulate the airflow.
- Diesel Engines: Control power output by regulating the quantity of fuel injected into the cylinder. Modern diesel engines may include a throttle valve to meet emissions standards.
Mechanisms
- Mechanical Linkage: Historically, throttle control was achieved through a direct mechanical linkage between the pedal and the throttle valve.
- Drive-by-Wire: Modern vehicles use electronic sensors and actuators controlled by the Engine Control Unit (ECU) to manage throttle operation.
Components
- Throttle Body: In fuel-injected engines, the throttle body controls the amount of air flowing into the engine. It often includes a throttle plate, mass airflow sensor, and sometimes an Idle Air Control Valve (IACV).
Multiple Throttle Bodies
High-performance vehicles may use multiple throttle bodies, or individual throttle bodies (ITBs), to improve throttle response and airflow.
Throttle in Different Engine Types
Steam Locomotives
The throttle, or regulator, controls the amount of steam admitted to the steam chests over the pistons. It is typically located in a steam dome to avoid liquid damage.
Rocket Engines
Throttle control in rocket engines involves varying the thrust level by regulating the flow of fuel and oxidizer to the combustion chamber. This is essential for powered landings and controlled acceleration.
Jet Engines
In jet engines, thrust is controlled by adjusting the amount of fuel flowing into the combustion chamber, similar to diesel engines.
Throttle Maintenance and Lifespan
The lifespan of a throttle in vehicles depends on driving style and vehicle type. Throttles often require cleaning after 100,000 to 150,000 kilometers to prevent malfunctions, which can be indicated by warning lights such as the EPC or check engine light.
Symptoms of Throttle Malfunction
- Poor idle
- Decreased engine power
- Poor fuel efficiency
- Bad acceleration
Regular maintenance and cleaning can extend the throttle’s lifespan.
Summary Table
| Engine Type | Throttle Function | Control Mechanism |
|---|---|---|
| Gasoline Engines | Regulates air or fuel-air mixture | Butterfly valve, drive-by-wire |
| Diesel Engines | Regulates fuel quantity | Mechanical linkage, drive-by-wire |
| Steam Locomotives | Controls steam admission | Poppet valve |
| Rocket Engines | Varies thrust level | Fuel and oxidizer flow control |
| Jet Engines | Controls thrust by adjusting fuel flow | Fuel flow control |
Conclusion
The throttle is a critical component in various types of engines, controlling power and speed by regulating fluid flow. Its design and operation vary significantly across different engine types, from internal combustion engines to steam locomotives and rocket engines. Regular maintenance is essential to ensure optimal performance and longevity.
For more detailed information, you can refer to the Wikipedia page on the throttle [1].
[glossary_wikipedia]This article relies largely or entirely on a single source. (February 2019) |
A throttle is a mechanism by which fluid flow is managed by constriction or obstruction.
An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term throttle has come to refer, informally, to any mechanism by which the power or speed of an engine is regulated, such as a car's accelerator pedal. What is often termed a throttle (in an aviation context) is also called a thrust lever, particularly for jet engine powered aircraft. For a steam locomotive, the valve which controls the steam is known as the regulator.
English
Pronunciation
- (Received Pronunciation) IPA(key): /ˈθɹɒt.l̩/
- (General American) IPA(key): /ˈθɹɔ.təl/, /ˈθɹɑ.təl/, /ˈθɹɑ.tl̩/
- Rhymes: -ɒtəl
Etymology 1
From Middle English *throtel, diminutive of throte (“throat”), equivalent to throat + -le.