Insulator

Abstract

An insulator (2) in which a housing (5) is integrally molded with a heat insulation section (20) at its lower part, where the housing (5) forms a part of a housing (64) of an acceleration pump (6). The construction enables the acceleration pump (6) to be placed at that portion directly around the insulator (2) that is conventionally a dead space, eliminating the need for a dedicated space for installing the acceleration pump to achieve space saving. In addition, because the acceleration pump (6) is at a portion around the heat insulation section (20), even if a pipe is used to interconnect a leading air passage (21) in the insulator and the acceleration pump (6), the length of the piping can be reduced to simplify the structure of the interconnection. Also, since the housing (5) is integrally formed with the heat insulation section (20), the number of parts can be reduced to reduce costs and facilitate assembly of the acceleration pump (6).

Description

technical field [0001] The present invention relates to heat insulators for engines, for example, to heat insulators used in layered scavenged two-stroke engines. Background technique [0002] In a two-stroke engine, the exhaust port and the scavenging port are opened and closed by the piston. When the exhaust port is opened by the descent of the piston, the combustion gas is exhausted as exhaust gas, and the mixed gas in the crankcase flows into the cylinder through the scavenging passage from the scavenging port opened approximately at the same time. Before the piston closes the exhaust port, the mixed gas that flows in scavenges the combustion gas remaining in the cylinder, and at the same time, a small amount of the mixed gas itself flows out. Therefore, although a small amount, the unburned fuel in the mixed gas is discharged together with the exhaust gas, resulting in a decrease in fuel utilization (fuel consumption) due to fuel loss, and it is necessary to prevent th...

AI Technical Summary

Problems solved by technology

[0008] However, in the accelerator device described in Patent Document 1, the accelerator pump is installed away from the heat insulator and the evaporator. Therefore, in addition to the heat insulator and the evaporator, it is necessary to secure an installation space for the accelerator pump separately, resulting in an increase in size. The problem

In addition, since the accelerator pump and the heat insulator are connected by pipes, when the accelerator pump is placed far away from the heat insulator and the carburetor, there is a problem that the communication structure based on the pipe becomes complicated.

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