JPH0330581Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a blower device for cooling a small portable engine used in a portable working machine or the like.

(b) Prior art and problems to be solved Conventionally, in this type of engine blower, a spiral-shaped fan with a cross-sectional area that gradually increases in the direction of rotation is attached to the outer periphery of a fan that is fixed to the crankshaft. An air passage was provided, and the blades of the fan were placed perpendicular to the direction of rotation to guide the air to the outer periphery of the cylinder. Since this centrifugal type engine forms an air passage around the outer circumference of the fan, the outer diameter of this part becomes large, making it unsuitable for use as a portable engine and becoming an obstacle to reducing weight and size. . For this reason, a blower device shaped like an axial fan that blows air in the axial direction with its blades tilted relative to the direction of rotation can be considered, but this type of fan has low blowing pressure and air flow, and is not very cooling. It has not been put into practical use because it has the disadvantage of reduced capacity.

In addition, in the past, small engines with cantilevered crankshafts were used to reduce weight, but in this case the recoil starter was usually placed between the fan located at the front (power extraction side) and the crankcase. The recoil starter fan is installed in The fan blade is installed on the front side of the rotating body, and the air from the fan flows forward.
Air did not flow sufficiently around the outer circumference of the cylinder.

(c) Means and action for solving the problem The present invention covers the leading edge of the vane perpendicular to the direction of rotation and blows air outward (radially outward from the center).
An annular front plate is fixedly provided to guide the air from the recoil starter in a rearward direction, and a guide is provided to diagonally cross the outer periphery of the recoil starter to guide the air blown from this vane plate to the outer periphery of the engine cylinder. A plate is installed to send the powerful air generated by the centrifugal air blower backwards, preventing it from flowing forward and around the crankcase, and effectively guiding it to the outside of the cylinder. Moreover, without increasing the outer diameter near the blower,
It is lightweight, has a simple structure, and can be installed compactly.

(d) Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In the figure, the engine 1 is configured as follows. That is, a crankshaft 9 is supported by the crankcase 3 via bearings 5 and 7.
Crank arm 11 provided at the rear end of crankshaft 9
One end of a connecting rod 13 is pivotally connected to the crank case 3, and the other end of the connecting rod 13 is pivotally connected to a slidable piston 17 in a cylinder 15 fixed to the crankcase 3. An ignition plug 19 is provided at the top of the cylinder 15. A carburetor 21 communicates with the rear surface of the crankcase 3. A bearing part 23 that holds the bearings 5 and 7 is provided protruding from the front part of the crankcase 3, and the recoil starter 25 is supported on the side by a case 27 that covers the outer periphery of the engine 1 with an appropriate gap on the outer periphery. has been done. The engine 1 is supported by the case 27 at the side of the crankcase 3 via a vibration isolator (not shown), and
The top of the cylinder 15 is also supported by a case 27 via a vibration isolator 29. crankshaft 9
A rotating body (magnetic foil in this embodiment) 31 and a centrifugal clutch 33 are arranged side by side at the front end of the crankshaft 9, and are fixed to the crankshaft 9 by a female threaded cylinder 35. The ignition coil 37 is located close to the outer periphery of the rotating body 31.
is provided, and generates electricity in response to a magnet (not shown) embedded in the outer periphery of the rotating body 31. A claw portion 39 is provided on the rear side surface of the rotating body 31 and engages with the recoil starter 25 in a detachable manner. On the front side of the rotating body 31, there is a vane plate 4 perpendicular to the rotation direction.
1 are arranged in parallel along the circumference. wing plate 4
An annular front plate 43 having a shape that covers the front edge of the recoil starter 25 to convert and guide the air from the outside to the rear is fixedly provided. A guide plate 45 for guiding air to the outer periphery of the cylinder 15 of the engine 1 is provided in a shape that partitions a gap between the engine 1 and the case 27. case 27
are divided along a vertical plane including the axis of the crankshaft 9, and are connected by screws 47. A boss portion 51 of a clutch drum 49 provided close to the outer periphery of the centrifugal clutch 33 is rotatably supported on the outer periphery of the female threaded cylinder 35, and a ring body 53 is fixed to the front side of the clutch drum 49. . A rubber vibration isolator 55 is removably engaged inside the ring body 53. One end of a transmission shaft 59 is engaged with an engagement tube 57 that is baked and fixed to the center of the vibration isolator 55 . Above the engine 1 in the case 27 is a fuel tank 6.
1 is provided.

In the above embodiment, the power of the engine 1 is
The vibration is transmitted from the centrifugal clutch 33 at the front end of the crankshaft 9 to the clutch drum 49, and passes through the vibration isolator 55.
It is transmitted to the transmission shaft 59. The air generated by the blades 41 is blown outward by centrifugal force, and the air that is flowing forward is directed towards the front plate 43.
It is guided outward by the guide plate 45, then sent backwards by the guide plate 45, and is sent to the outer periphery of the cylinder 15 to cool the cylinder 15.

(e) Effect of the invention Since the invention has the configuration as described in the claims, by providing a front plate with a simple structure, powerful centrifugal air can be sent rearward to the outer periphery of the cylinder. It is possible to efficiently guide the air, reduce the outer diameter near the blower, and be lightweight and compact.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented in other embodiments as well. Further, the symbols shown in the claims do not limit the technical scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of one embodiment of the present invention, and FIG. 2 is a front sectional view of the main parts. 1...Engine, 9...Crankshaft, 15...
Cylinder, 25...Recoil starter, 27
... Case, 31 ... Rotating body, 41 ... Wing plate, 4
3...Front side plate, 45...Guidance plate.

Claims (1)

[Scope of utility model registration request] A rotating body 31 fixed to the front end of the crankshaft 9 is provided in front of the recoil starter 25 provided at the front of the crankshaft 9 of the engine 1 housed in the case 27, and a rotating body 31 fixed to the front end of the crankshaft 9 is provided on the front side of the rotating body 31. Vane plates 41, 41 perpendicular to the vane plate 41 are fixedly arranged in a radial direction, and an annular front plate 43 is fixedly attached to cover the front edge of the vane plate 41 to convert and guide the air blow from the outside direction to the rear direction. At the same time, the blade plate 4 is provided diagonally across the outer periphery of the recoil starter 25.
1. A blowing device for an engine, characterized in that a guide plate 45 is provided for guiding the blowing air of 1 to the outer periphery of a cylinder 15 of an engine 1.