CAR-Automobile Engine Group comprehensive introduction to the body

Body composition engine is the skeleton is the engine agencies and system installed base, its inner and outer engine installed in all the major parts and accessories, under various loads. Therefore, the body must have enough strength and stiffness. Block group from the main cylinder block, crankcase, cylinder head and cylinder pad, and other component parts. 1. Cylinder body (Figure 2-1) The water-cooled engine cylinder block, crankshaft, and often turns into one box, called the cylinder body - crankcase and cylinder body can be called. Cylinder general use of gray iron cast, the top of the cylinder body known as the cylindrical cavity cylinder, the crankshaft bearing for the second half of the crankcase, crankshaft its campaign for the inner cavity space. The cylinder block casting many internal stiffener, cooling water jacket and lubricants Road. Cylinder body should have sufficient strength and stiffness, according to the cylinder body and the oil pan installation location different plane, usually the cylinder body is divided into the following three forms. (Figure 2-2) (1) General-cylinder body characterized by plane and oil pan installation crankshaft rotation center at the same level. The advantages of such a cylinder body height is small, light weight, compact, easy processing, crankshaft removable convenience; But its weaknesses are less stiffness and strength (2) gantry-type cylinder of the features of sump installation of the plane below the crankshaft rotational center. The advantage is the strength and stiffness is good, can withstand greater mechanical load; But its shortcomings of the process is poor, bulky structure, processing more difficult. (3) tunnel-type cylinder of this form of a cylinder of the crankshaft main bearing hole for the overall style, using rolling bearings, main bearings hole larger, crankshaft load from the rear of the cylinder. The advantage is compact structure, stiffness and strength well, but its disadvantages are high precision machining, the process of the poor, crankshaft removable inconvenient. To enable the inner surface of the cylinder under high temperature in the normal work of the cylinder gas cylinder head must be carried out properly cooling. There are two cooling methods, is a water-cooled, and the other is air-cooled (Figure 2-3). The cylinder water-cooled engine cylinder head around and gas processing in both sets of a cooling water, and gas cylinder head and cylinder block the same set of cooling water, cooling water Inner constantly circle in the water, taking some heat built on the cylinder and the cylinder cooling effect. Hyundai Motor on the basic use of multi-cylinder water-cooled engine, multi-cylinder engine, the cylinder engine with a decision to form the size and shape structural characteristics of the engine body stiffness and strength also have influence and a bearing on the overall layout of vehicles. In accordance with the arrangement of different cylinder, the cylinder body also can be divided into separate-, V-and home-three (Figure 2-4). (1) In-line Each cylinder engines lined up one, the general layout is vertical. Separate-cylinder block structure is simple, easy processing, but the length and height of larger engines. Following the general six-cylinder engine to use a separate type. For example, Jetta sedan, Beverly sedan, the red flag used by car engines that are used in-line cylinder. Some of the cars in order to reduce engine height, tilt angle of the engine. (2) V Formed two cylinder, two-cylinder around the angle between the centerline of γ <180 °, known as V-type engine, a V-type engine compared with the inline engine, shortened the length and height of the body, increasing the stiffness of the cylinder block, reducing the weight of the engine, but the width has increased engine , and the shape more complex, processing difficulties, generally for the more than 8-cylinder engine, six-cylinder engine also used this form of a cylinder body. (3) Purchase of Formed two cylinder, about two surface of the cylinder at the same level, that is, about two-cylinder angle between the centerline of γ = 180 °, known as the home-style. It is characterized by a high degree of small, the overall layout of convenience, to air-cooled. Application of this cylinder less. Cylinder boring directly in the cylinder body called Integral cylinder, the cylinder of the overall strength and stiffness is good, can withstand greater loads, the material requirements of this high cylinder, high costs. If the cylinder into separate manufacturing cylindrical parts (that is, the cylinder sets), and then loaded to the cylinder body. So, wear-resistant cylinder sets using high quality materials, the availability of lower prices cylinder general materials, which reduces manufacturing costs. At the same time, the cylinder can be set out from the cylinder body, thus facilitating repair and replacement, and can greatly extend the life of the cylinder. A dry cylinder sleeve cylinder kits and Wet Sleeve two (Figure 2-5). Dry cylinder liner features packaged into the cylinder after cylinder body, not its outer wall direct contact with the cooling water, and the wall of the cylinder direct contact thinner wall thickness, generally 1 to 3 mm. It is the overall merits of the cylinder body, strength and stiffness are good, but processing more complex inner and outer surfaces need to be finished, removable inconvenient, Thermal bad. Wet Sleeve is the characteristics of the cylinder sets into the cylinder after its outer wall direct contact with the cooling water, only in the cylinder sets, one each under the ring Strip and the cylinder body contact, the general thickness of 5 to 9 mm. It Thermal good, uniform cooling, processing easier, usually requires only finishing inner surface, and contact with the outer surface of the water does not need processing, disassembly and assembly convenience, but the disadvantage is strength, stiffness of the cylinder sets of proteins are not good, and could easily have leakage phenomenon. Some measures should be taken leakproof. 2. Crankcase Installation of the lower cylinder crankshaft to the site known as the crankcase, crankshaft box at the crankcase and the crankcase. The crankcase and cylinder body turns into one, under the crankcase lubricants used for storage, and closed on the crankcase, it is also known as the oil pan map (Figure 2-6). Sump force is very small, generally use thin steel plate stamping from its shape depends on the overall layout and the engine oil capacity. The contents are stable oil sump baffles to prevent vehicles moving at top excessive fluctuations in the oil surface. Put oil pan bottom are equipped with the oil plug, plug oil usually put on permanent magnets installed to adsorption lubricants in metal shavings, reduce engine wear. In between the upper and lower crankcase with Congress liner to prevent oil leakage. 3. Cylinder Head (Figure 2-7) Installed in the cylinder head above the cylinder block, cylinder and from the upper part of a sealed combustion chamber. With its regular contact with high temperature and high pressure gas, under tremendous heat load and mechanical load. The water-cooled engine cylinder head with the internal cooling water system sets and Head End under the cooling water hole and block the cooling water hole the same. Use circulating cooling water to high temperature combustion chamber, and other parts. Jin also equipped with cylinder head, exhaust portal, catheter valve hole for the installation Jin, exhaust valve, and exhaust and inlet channel access. The cylinder gasoline engine installed spark plugs are covered with processing the hole, and covered with processing cylinder diesel engine injector installation of a hole. Overhead Camshaft engine cylinder covered with the camshaft bearings are also processing hole for the installation of camshaft. Figure 2-7 Cylinder Head generally use the gray cast iron or cast iron alloy, the thermal conductivity of aluminum alloy good, helping improve the compression ratio, aluminum alloy cylinder head in recent years been adopted in more and more. The cylinder head is an integral part of the combustion chamber, the combustion chamber shape on the engine work very influential, since the gasoline engine and diesel engine combustion different ways, the composition of its cylinder covered with greatly different part of the combustion chamber. The gasoline engine cylinder covered in the main combustion chamber, the combustion chamber and the main diesel engine piston in the top of the pit. Here only on the gasoline engine combustion chamber, the combustion chamber diesel engine on diesel supply department introduced. Gasoline engine combustion chamber of the three common forms (Figure 2-8). (1) hemispherical combustion chamber Compact hemispherical combustion chamber, spark plugs are deployed in the central chamber, flame trip short, so high combustion rate, less heat dissipation, thermal efficiency. This structure also allows the combustion chamber of double valve arranged inlet diameter larger, more efficient so inflated, although the allocation of gas agencies become more complex, but to exhaust purification, in the car engine is widely used. (2) wedge-shaped combustion chamber Wedge-shaped combustion chamber structure is simple, compact, heat a small area, heat loss is small, can guarantee mixture formed in the compressed itinerary good eddy current campaign, helping improve the quality of hybrid gas mixture, Inlet resistance small, inflatable increased efficiency. Formed a valve, valve trains simple, but the spark plugs placed wedge combustion chamber height, flame propagation distance longer, Cherokee cars using this form of engine combustion chamber. (3) basin-shaped combustion chamber Basin-shaped combustion chamber, the cylinder head and good technology, low manufacturing costs, but vulnerable valve diameter limit, Jin, the exhaust effects worse than the hemispherical combustion chamber. Jetta sedan engine, the Audi car engine combustion chamber shape used pots. 4. Cylinder pad (Figure 2-9) Cylinder pad mounted on the cylinder head and cylinder block between its function is to ensure that the cylinder head and cylinder block access of the seal to prevent leakage, water leakage and oil spills. Cylinder pad material to have a certain flexibility to compensate surface roughness combine to ensure that sealed at the same time have a good heat resistance and pressure, high temperature under high pressure is not burning, not deformed. The present application is more horsepower - cylinder structure of the cotton pad, as magma - cotton pad flanging Department cylinder three-horsepower, clamping asbestos difficult than when the deformation. Some asbestos engine also used in the weaving center with a gang-screen or plate frame, two rubber binder with asbestos and pressure into the cylinder gasket. Installation cylinder pad, the first to check the quality and cylinder pad integrity of all cylinder pad to the hole and the hole on the cylinder body alignment. Second, we must strictly in accordance with the requirements of Hong statement, the cylinder head bolts. Tightening cylinder head bolts, it must be central to the symmetric extension of the order at around 2 to 3 times, the last time Tightening torque to the provisions. This article from: China Automotive Technology Forum [url] http://bbs.qichejishu.com [/ url] more exciting waiting for you!