Pancake engine cylinder block

Abstract

The invention relates to the field of engines, in particular to a pancake engine cylinder block. The pancake engine cylinder block comprises a cylinder block body, crankshaft bearing pedestals, cam bearing pedestals, a cylinder barrel, main oil ways and hydraulic tappet mounting holes. The pancake engine cylinder block is integrally formed in a casting mode. The cylinder block provided by the invention is integrally formed in the casting mode, due to the machining technology, the cylinder block shares a set of benchmarks during the machining process, no mould assembling is adopted, it can be guaranteed that the distance between a left cylinder cover mounting surface and main bearing holes is the same as the distance between a right cylinder cover mounting surface and the main bearing holes, meanwhile, the planeness of the left and right cylinder cover mounting surfaces can be guaranteed quite easily, and the machining process is simple.

Description

technical field [0001] The invention relates to the field of engines, in particular to a horizontally opposed engine block. Background technique [0002] The traditional horizontally opposed engine block is divided into a left block and a right block. The left and right blocks are frames for each other, sealed by a circle of bolts on the joint surface of the left and right blocks, and the sealing surface needs to be glued. This type of engine block There are several disadvantages: [0003] 1. Poor sealing: This kind of engine block will have a "T-shaped" sealing area when it is connected with the gearbox or timing cover. According to past experience and tests, it has been proved that most of the areas where the engine has liquid leakage or leakage In the "T" seal area of ​​the engine. [0004] 2. Difficulty in processing: Before machining the crankshaft bearing hole and cam bearing hole of the traditional cylinder block, it is necessary to use the crankshaft bearing housin...

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Problems solved by technology

[0003] 1. Poor sealing: This kind of engine block will have a "T-shaped" sealing area when it is connected with the gearbox or timing cover. According to past experience and tests, it has been proved that most of the areas where the engine has liquid leakage or leakage In the "T" seal area of ​​the engine

[0004] 2. Difficulty in processing: Before machining the crankshaft bearing hole and cam bearing hole of the traditional cylinder block, it is necessary to use the crankshaft bearing housing studs and corresponding nuts to tighten the left and right cylinder blocks according to the pre-tightening force of the design state, which is the so-called cylinder block assembly. box processing

However, the mounting surface A of the right cylinder body and the mounting surface C of the left cylinder body must be machined in place before the box closing process, because there are studs and corresponding nuts on the A surface and the C surface after the box closing process, and the fasteners block the tool and cannot be combined. After-box processing of A and C sides

At this time, reprocessing the crankshaft bearing hole and cam bearing hole will cause deformation due to the pre-tightening force of the bolts on the surface A and surface C. It is necessary to ensure the flatness of A and C, and at the same time ensure that the distances from B to A and B to C are the same. Very difficult to process

[0005] 3. Partial wear of the piston and large amount of gas leakage: because during the processing process, the A surface and the C surface are processed according to the respective precision standards of the left and right cylinders, and at the same time, the parallelism of A and C cannot be guaranteed through reprocessing after A and C are combined. As a result, the cylinder bores of the left and right cylinders are not distributed at 180°, so that the piston will be worn out during the movement, and the gas leakage will be large, and it may cause the engine to scuff.

[0006] 4. The performance of the engine is unstable, the vibration is large, and the service life is short: it is difficult to ensure the distance from B to A and B to C during the processing of the cylinder block. These two distances will affect the compression clearance of the engine, and then affect the compression ratio of the engine , resulting in inconsistent burst pressures of the two opposing cylinders during the operation of the engine, resulting in unstable engine performance, high vibration and noise, and short service life

[0007] 5. The mass of the cylinder body is large: the left and right sides of the cylinder body form a frame for each other, and the structure is relatively thick. If it is used as aerodynamic equipment, the market competitiveness will decrease due to the large weight

[0008] 6. High finished product: In the production process of this kind of engine cylinder, two sets of molds should be opened for the left and right cylinders respectively, and the production cost is high

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