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What is the role of the exhaust manifold? Introducti₩on to the role of the exhaust manifold

  • Time of issue:2021-08-13

What is the role of the exhaust manifold? Introduction to the role of the exhaust manifold✘

(Summary description)With the development of the times, the car has become a means of transportation that ¶we can often use. Whether it is work in our daily life or traveli≤ng in our leisure time, we will think of him for the first time. ∑Since the car is already for us It's very important, and ≤we need to understand him better. Today, I will introduce to you what the func£tion of the exhaust manifold is!

　　Exhaust manifold is connected with the engine cylinder bloc"k, and the exhaust gas of each cylinder is collected and guidφed into the exhaust manifold, with branched pipelines. The main requirement for it is to reduce ✔the exhaust resistance as much as possible and avoid muπtual interference between the cylinders. When the exhaust is too concentra ted, the cylinders will interfere with each other, that is, when a certain cylinder is exha‍usted, it happens to encounter the undischarged exhaust gas ‌from other cylinders. In this way, it will increase the resistance of ÷the exhaust, thereby reducing the output of the en©gine. The solution is to separate the exhaust of each cylinder as m$uch as possible, one branch per cylinder, or one branch for twλo cylinders, and to lengthen and shape each branch as much as possible-to reduce the m'utual influence of the gas in different pipes. In order to reduc∑e exhaust resistance, some racing cars use stainless st±eel pipes to make exhaust manifolds.

　　In the range of room temperature to working temperature, the material should be¥ as little as possible without phase change or as little as poss₽ible. Because the phase change will cause volume changes, causing internal str✔ess or deformation, affecting the performance and life of the product. Thereσfore, the matrix material is preferably a stable ferrite or austenitic struct&ure. The destruction of cast iron parts working under high teαmperature conditions is mainly manifested as corrosion under high temperature conditions. After the₽ component phases in the structure are oxidized (such a✘s graphitic carbon), the volume of the oxide is larger than the original volume, causing irre©versible expansion of the casting. Compared with the three g★raphite forms of flake, vermicular, and spherical grap hite, spheroidal graphite has the best high temperature resistance. Th e reason is that during the solidification process of' cast iron, flake graphite grows as the leading phase. The graphite in €the eutectic group constitutes a continuous branched thre∞e-dimensional form. At high temperatures, when oxygen penetrates inεto the metal, after the graphite is oxidized, a microscopic channel is formed to ac celerate the oxidation process. When spheroidal graphite is nucleated, it grows to a certain★ size and is surrounded by the matrix and exists as an isolated ball. After t✔he graphite ball is oxidized, it will not form a channel, thus weakening the furt±her progress of oxidation. Therefore, the high temperature oxidation resistance of nodular cas↓t iron It is better than other forms of graphite, and the oxidized pores' have less influence on the high temperature strength of← cast iron than other forms of graphite, and vermicular ink is₹ somewhere in between.

　　 There are many types of heat-resistant and high-temperat₽ure resistant metal materials, but due to the complicated shape of the ex✘haust manifold, the material used to manufacture the exhaust manifold must h≤ave good manufacturability, and its cost must meet the needs of mass♠ production in the automotive industry.

  • Time of issue:2021-08-13
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With the development of the times, the car has become a means of transportation tha&t we can often use. Whether it is work in our daily life or traveling in our leisur×e time, we will think of him for the first time. Sinπce the car is already for us It's very important, and we need to understa nd him better. Today, I will introduce to you what the function of& the exhaust manifold is!

　　Exhaust manifold is connected with the engine cylinder block, and the exhaust gas of ea&ch cylinder is collected and guided into the exhaust manifold, with branλched pipelines. The main requirement for it is to reduce the exhau©st resistance as much as possible and avoid mutual interference between tσhe cylinders. When the exhaust is too concentrated, ↕the cylinders will interfere with each other, that is, when a certain cylinder is exhausted, it h™appens to encounter the undischarged exhaust gas from other cylinders. In this way, it will i✘ncrease the resistance of the exhaust, thereby reducing ↔the output of the engine. The solution is to separate the exhaust of each ♣cylinder as much as possible, one branch per cylinder, or one branch for t≤wo cylinders, and to lengthen and shape each branch as m♥uch as possible-to reduce the mutual influence of the gas in different pipes. In ord♦er to reduce exhaust resistance, some racing cars use stainless steel pi₽pes to make exhaust manifolds.

　　In the range of room temperature to working temperature, the material shoul×d be as little as possible without phase change or as little as possible. Because the phase± change will cause volume changes, causing internal stress or deformation, affecting the per₽formance and life of the product. Therefore, the m©atrix material is preferably a stable ferrite or austenitic structure. The d'estruction of cast iron parts working under high temperature conditions is main→ly manifested as corrosion under high temperature conditions. After the component phases in the st✘ructure are oxidized (such as graphitic carbon), the volume of the oxide is larger ₩than the original volume, causing irreversible expansion of the casting. Coαmpared with the three graphite forms of flake, vermicular, and spherical graphite, spheroidal πgraphite has the best high temperature resistance. The reason is that during t★he solidification process of cast iron, flake graphite g'rows as the leading phase. The graphite in the eutectic groupΩ constitutes a continuous branched three-dimensional form. At high tempera€tures, when oxygen penetrates into the metal, after the graphite is oxidized, a microscopi€c channel is formed to accelerate the oxidation process. When spheroidal ¥graphite is nucleated, it grows to a certain size and is surrounded by the matrix and exists as± an isolated ball. After the graphite ball is oxidized, it will not form a channel, thus weaken₹ing the further progress of oxidation. Therefore, the high te​mperature oxidation resistance of nodular cast iron It βis better than other forms of graphite, and the oxidized pores have less influence on the hiπgh temperature strength of cast iron than other forms of graphite, and vermicula←r ink is somewhere in between.

　　 There are many types of heat-resistant and high-temperature≤ resistant metal materials, but due to the complicated shape of the exhaust mani×fold, the material used to manufacture the exhaust manifold must have good manu•facturability, and its cost must meet the needs of mass producti∞on in the automotive industry.

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