Lost Wax Investment Castings For Automotive Intake Manifolds

Product Introduction

The reason for the name

The intake manifold is located between the throttle valve and the engine intake valve. The reason why it is called a manifold is that after the air enters the throttle valve and passes through the buffer system of the manifold, the airflow path diverges here, corresponding to the number of cylinders of the engine. For example, there are four channels in a four-cylinder engine and five channels in a five-cylinder engine, and the air is introduced into each cylinder respectively. For a naturally aspirated engine, since the intake manifold is located behind the throttle valve when the engine throttle opening is small, the cylinder cannot absorb enough air, which will cause a high vacuum in the manifold; When the degree is large, the vacuum degree in the intake manifold will become smaller. Therefore, the fuel injection engine will install a pressure gauge on the intake manifold to supply the ECU to determine the engine load and give the right amount of fuel injection.

Different purposes

Manifold vacuum can be used not only to provide pressure signals to determine engine load but also for many purposes! For example, the brakes also need to be assisted by the vacuum of the engine, so when the engine is started, the brake pedal will be much lighter because of the vacuum assistance. There are also some forms of cruiser control that utilize manifold vacuum. Once these vacuum tubes are leaked or improperly modified, the engine control will be out of control and the brakes will also be affected. Therefore, readers are advised not to make improper modifications to the vacuum tubes to maintain driving safety.

Ingenious Design

The design of the intake manifold is also very knowledgeable. In order to have the same combustion conditions for each cylinder of the engine, the length and curvature of the manifold of each cylinder should be the same as possible. Since the engine completes the running program with four strokes, each cylinder of the engine will intake air in pulses. According to experience, the longer manifold is suitable for low-speed operation, while the shorter manifold is suitable for high-speed operation. Therefore, some models will use variable-length intake manifolds, or continuously variable-length intake manifolds, so that the engine can perform better in all speed ranges.

Plasticization of the engine intake manifold

• Superiority

The main advantages of plastic intake manifolds are lower cost and lighter weight. In addition, since PA has a lower thermal conductivity than aluminum, the fuel nozzle and incoming air are cooler. It can not only improve the hot start performance, increase the power and torque of the engine, but also avoid the heat loss in the pipe to a certain extent during the cold start, and accelerate the increase of the gas temperature, and the inner wall of the plastic intake manifold is smooth, which can reduce the airflow resistance, thereby improving the engine performance.

In terms of cost, the material cost of the plastic intake manifold is basically the same as that of the aluminum intake manifold. The plastic intake manifold is molded at one time and has a high pass rate; while the casting yield of the aluminum intake manifold is low, and the machining cost is relatively high. Therefore, the production cost of plastic intake manifold can be reduced by 20%-35% compared with aluminum intake manifold.

• Material requirements

1) High-temperature resistance

The plastic intake manifold is directly connected to the engine cylinder head, and the temperature of the engine cylinder head can reach 130~150℃. Therefore, the plastic intake manifold material is required to withstand a high temperature of 180°C.

2) High strength

Lost Wax Investment Castings for Automotive Intake Manifolds are installed on the engine, which must bear the vibration load of the automobile engine, the inertia force load of the throttle valve and the sensor, the intake pressure pulsation load, etc., and also ensure that the engine will not be affected by the high-pressure pulsation pressure when the engine is abnormally tempered. blasting.

3) Dimensional stability

The dimensional tolerance requirements for the connection between the intake manifold and the engine are very strict, and the sensors and actuators on the manifold must be installed accurately.

4) Chemical stability

The plastic intake manifold is in direct contact with gasoline and antifreeze coolant during work. Gasoline is a strong solvent, and ethylene glycol in the coolant will also affect the performance of the plastic. Therefore, the chemical stability requirements of the plastic intake manifold material are Very high, subject to rigorous testing.

5) Thermal aging stability

Automobile engines work under very harsh ambient temperatures, and the working temperature changes back and forth between 30 and 130°C. The plastic material must be able to ensure the long-term reliability of the manifold.

Detection Systems

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