Negative pressure supply device of engine

Abstract

Disclosed is a negative pressure supply device of an engine, which can simplify a piping structure and improve rigidity of a cylinder cover. A vacuum pump (3) is assembled on the cylinder cover (1); a negative pressure passage (24) in the cylinder cover, which communicates a suction inlet (15) connected with a pump insuction inlet (27) of the vacuum pump (3) with negative pressure taking outlets (17, 18) connected with negative pressure working equipment, is formed within a wall of the cylinder cover (1); and a piping connection part (26) used for connecting the negative pressure taking outlets (17, 18) and connected with the negative pressure passage (24) in the cylinder cover is configured at an outer side of a wall part of the cylinder cover (1). In the circumstance of forming two connection holes (29) opposite to each other with an axis being orthogonal to a communication path (28), a rib forming an outer wall of the communication path (28) and the connection holes (29) and an outer side of the wall part of the cylinder cover (1) are continuously formed, and the rigidity of the cylinder cover (1) is improved.

Description

technical field [0001] The present invention relates to a negative pressure supply device for supplying negative pressure to a negative pressure working device used in a vehicle, and is particularly suitable for a negative pressure supply for an engine that supplies negative pressure to a negative pressure working device through a vacuum pump mounted on a cylinder head of an engine. device. Background technique [0002] Vacuum pumps have the function of generating negative pressure using rotational driving force, and the negative pressure is used in engine negative pressure operating equipment such as vacuum boosters for brakes and VSV (Vacuum Switching Valve: Vacuum Switching Valve) for turbocharger control. As a negative pressure supply device for an engine using such a vacuum pump, there is, for example, the negative pressure supply device described in Japanese Unexamined Patent Application Publication No. 2003-74411. In the negative pressure supply device of the engine,...

AI Technical Summary

Problems solved by technology

Such a vacuum pump is often assembled on the cylinder head, but in the negative pressure supply device of the engine described in Japanese Patent Application Laid-Open No. 2003-74411, although the negative pressure working equipment is arranged near the cylinder head, it still consists of pipes made of metal. The negative pressure forming passage member connects these negative pressure working equipment and the vacuum pump, so the piping structure is complicated, and the number of parts such as fixing pieces for fixing metal pipes is large.

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