Four-cycle engine

Abstract

To facilitate forming of cylinder head which needs a plurality of bore workings different in working axis for intake / exhaust valves or plugged tubes or the like, and provide a head carrier contributing to engine stable support. The engine superimposes a cylinder block 3, a cylinder head 4 and a cylinder head cover 5 in this order, and provides an active valve mechanism of SOHC model arranging an intake valve 16 and an exhaust valve 17 on the cylinder head 4. A head cover mating line L2, which is a parallel line against a mating face between the cylinder head 4 and the cylinder head cover 5, is made to be downwardly slanted toward front side against a cylinder mating line L1, which is a parallel line against a mating face between the cylinder block 3 and the cylinder head 4, and an axial line J2 of the exhaust valve 17 and an axial line J3 of the plugged tube 50 are made to cross with the head cover mating line L2 at right angles. Further, the head carrier 19 is integrally formed on the most highest portion of cylinder head 4 rear face at upper location of an intake port 12.

Description

technical field [0001] The invention relates to a 4-stroke engine used in a motor vehicle and the like, in particular to an optimized structure for the combination of a cylinder head and a cylinder head cover. Background technique [0002] Existing 4-stroke engines have a double overhead camshaft (DOHC) type engine in which different camshafts are used to drive intake valves and exhaust valves respectively. As such examples, there are Japanese Patent Laid-Open No. 1-132485 (pages 9 to 10, FIGS. 4 and 5 ) and Japanese Patent Laid-Open No. 9-287464 (0021 (identifier), FIG. 2 ). These documents disclose that the joining surface of the cylinder head and the head cover (hereinafter referred to as the head cover joining surface) is inclined relative to the joining surface of the cylinder head and the cylinder block (hereinafter referred to as the cylinder joining surface). In this way, the cylinder head can be downsized. [0003] Furthermore, Japanese Patent Publication No. 2002...

AI Technical Summary

Problems solved by technology

This point is the same even in the case of inclining the joint surface of the cylinder head cover. The machining axes of the intake and exhaust valves are different and cannot be unified. Therefore, many processes or time are required.

Images