Agriculture trade data by HS code

List of the contents of this article:

• 1,Agriculture trade data by HS code Engine placement method
• 2, Why do sports cars like to adopt the front-middle engine and rear-wheel drive layout?
• 3, Why does the country prohibit the middle engine

Engine placement mode

1. The placement method of the engine is forward: placed in front of the first row of seats, front of the front drive (FF) and front Drive (FR) is the most common; middle position: placed behind the first row of seats, the middle rear drive (MR) is common, with only 2 seats, excellent curve performance but poor linear stability. General sports cars will adopt this form.

2. Generally, cars with vertical engines will try to put the engine backwards. The middle engine is also easier to balance the front and rear counterweights of the body. It is difficult for cars with rear engines to balance the front and rear weights of the body, and there are very few cars with rear engine layouts. The Porsche 911 series engine is a rear engine, and the rear engine is placed behind the rear axle.

3. The arrangement of the engine on the car is as follows: 1. Front horizontal, the most commonly used medium and low-speed cars, suitable for the front drive structure. The advantage is simple, the disadvantage is that it is easy to push the engine back and squeeze the cockpit after a crash. 2. Front vertical, also suitable for front-wheel drive, more suitable for rear-wheel drive and four-wheel drive for It's just a front-wheel drive car.

4. The engine arrangement can be divided into in-line V-type, W-type, horizontal H-type. The difference between them is1 The most commonly used is "in-line", that is to say, 4 cylinders or multiple cylinders are arranged in a row and placed on the crankshaft. The advantage is simple structure. The 4-cylinder engine is suitable for small cars 2V type, that is, the cylinder is divided into two.

5. Engine front-wheel drive (FF) Engine front-wheel drive is a popular layout form on automobiles. It has the characteristics of compact structure, reducing the mass of the car, reducing the height of the body floor, improving the stability of control when driving at high speed, and high power transmission efficiency.

6. Method/Steps Engine layout: front engine: in front of the first row of seats, the most common model is front drive (FF). FF is the most common driving type in family cars. About 80% of family cars only use front-wheel drive, which has the advantages of wide and comfortable driving space, good steering characteristics, good control performance and so on.

Why do sports cars like to adopt the front-middle engine and rear-wheel drive layout?

1. The central engine is also to move the center backwards, which can eliminate the drive shaft compared with the layout of the front and rear drive (FR), reduce weight and transmission loss, and increase transmission efficiency.

2, RR, Porsche, Ferrari, Lamborghini and other sports cars all like to adopt it. The reason is relatively simple, that is, the front and rear couperweight ratio of the vehicle is more reasonable. At the same time, it also reduces the length of the transmission shaft and reduces power loss. Disadvantages: There are few models used and the cost is high.

3. The front engine is the first because the design is obviously less difficult than the rear and middle engines, and the cost is low. Some entry-level sports cars such as Hyundai Coolpie and Audi TT adopt this method; those who have played with four-wheel drive should know that the front engine also has another advantage, which is conducive to cornering and throwing. Tail.

4. The characteristic of the middle of the engine is to place the engine with the most inertia in the vehicle in the center of the car body, which can make the body weight distribution close to the ideal equilibrium state.Generally speaking, only those supercars or sports cars that pay attention to driving use central engines.

Why does the country prohibit the middle engine

1. The country prohibits the middle engine because the middle engine is less widely used, mainly for the following reasons: high cost, safety and practicality. High cost: Compared with the front or rear engine, the design and manufacture of the middle engine is more difficult, requiring a higher level of technology and production costs, so the price is also higher.

2. Because once the middle engine is out of control or side slips, it is easy to oversteer once it is out of control or slips. Due to the high research and development cost and technical requirements of mid-engines, many automobile manufacturers do not manufacture mid-engines, so there are few mid-engine models sold in the Chinese market.

3. The reason why the country prohibits the middle engine is for safety reasons. Cars with central engines are rear-wheel drive or four-wheel drive. The center of the engine is characterized by placing the engine with the most inertia in the vehicle in the center of the car body, so that the body weight distribution is close to the ideal equilibrium state. The disadvantage of the middle engine is that the engine is in the middle, resulting in a narrow compartment.