초록 ▼

An engine-driven work machine is provided in which an engine/work machine unit (5) and an exhaust muffler (23) are housed in a box (30), the box (30) is provided with a cooling air passage (44) that passes the area around the engine/work machine unit (5) and the exhaust muffler (23), and a cooling f

An engine-driven work machine is provided in which an engine/work machine unit (5) and an exhaust muffler (23) are housed in a box (30), the box (30) is provided with a cooling air passage (44) that passes the area around the engine/work machine unit (5) and the exhaust muffler (23), and a cooling fan (15) driven by the engine (2) is disposed in the cooling air passage (44), wherein the box (30) is provided with blocking means (51) for blocking the cooling air passage (44) between the engine (2) and the exhaust muffler (23) when running of the engine (2) is stopped. The heat of the high temperature exhaust muffler can thus be prevented from affecting the engine/work machine unit even when running of the engine is stopped, while maintaining the soundproofing of the box housing the unit, etc.

대표청구항 ▼

The invention claimed is: 1. An engine-driven work machine in which an engine/work machine unit (5) is formed by joining an engine (2) and a work machine (4) driven by a crankshaft (3) of the engine (2), the engine/work machine unit (5) and an exhaust muffler (23) joined to the engine (2) are house

The invention claimed is: 1. An engine-driven work machine in which an engine/work machine unit (5) is formed by joining an engine (2) and a work machine (4) driven by a crankshaft (3) of the engine (2), the engine/work machine unit (5) and an exhaust muffler (23) joined to the engine (2) are housed in a box (30), the box (30) is provided with a cooling air passage (44) that reaches an air outlet (40) opening on an outer face of the box (30) from an air inlet (39) opening on the outer face of the box (30) while passing sequentially via the area around the engine/work machine unit (5) and the area around the exhaust muffler (23), and a cooling fan (15) is provided for generating a flow of air in the cooling air passage (44) when the engine (2) is running, characterized in that the box (30) is provided with blocking means (51) for blocking the cooling air passage (44) between the engine (2) and the exhaust muffler (23) when running of the engine (2) is stopped. 2. The engine-driven work machine according to claim 1, wherein the box (30) is equipped with a dividing wall (38) for compartmentalizing the interior thereof into a unit chamber housing the engine/work machine unit (5) and a muffler chamber (35) housing the exhaust muffler (23), and the dividing wall (38) is provided with a communicating opening (43), which becomes part of the cooling air passage (44), and the blocking means (51), which can block the communicating opening (43). 3. The engine-driven work machine according to claim 2, wherein the muffler chamber (35) has an air outlet (40) opening on a bottom wall. 4. The engine-driven work machine according to claim 2 or 3, wherein the muffler chamber (35) has a heat-insulating layer (70) formed on an inner face from a heat-insulating material, and an inner face of the heat-insulating layer (70) is covered with a thermally conductive body (71). 5. The engine-driven work machine according to claim 4, wherein the blocking means (51) is arranged so as to attain an open state when an intake negative pressure of the engine (2) is generated and to attain a blocking state when the intake negative pressure disappears. 6. The engine-driven work machine according to any one of claims 1, 2, or 3 wherein the blocking means (51) is arranged so as to attain an open state when an intake negative pressure of the engine (2) is generated and to attain a blocking state when the intake negative pressure disappears.