JP2000192815A - Centrifugal cooling fan of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a quantity of air fed by a centrifugal cooling fan and feed cooling air sufficeintly even to a crank case behind a flywheel. SOLUTION: A plurality of vanes 8 are radially arranged on a main plate 7 of a centrifugal cooling fan 6. The main plate 7 is fixed on one end face of a flywheel of an engine in a state that it is overlapped on the same shaft. The vane 8 is extended so as to protrude in the centrifugal direction more than a peripheral fringe of the main plate 7. Since the vane 8 protrudes in the centrifugal direction more than the peripheral fringe of the main plate 7 of the cooling fan 6, the vane 8 is enlarged by an amount of the protruding vane part 8a and a quantity of air fed increases. Moreover, it is possible to suppress an increase of engine dimension in the axial direction of the cooling fan 6. Consequently, the increase of the quantity of air fed and miniaturization of the engine are compatible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a centrifugal cooling fan used for an air-cooled engine such as a diesel engine and a gasoline engine.

[0002]

2. Description of the Related Art A centrifugal cooling fan of this type is constructed as follows, for example, as shown in FIG. That is, the main plate (41) of the centrifugal cooling fan (40) is fixed on the front surface (right side in FIG. 3) of the flywheel (3) of the engine in a coaxially stacked state, and the main plate (41) is fixed. Multiple vanes (4
2) is arranged radially.

In order to improve the cooling performance of the cooling fan (40), the size of each vane (42) is increased to increase the amount of air to be blown. Increasing the size in the front [rightward direction in FIG. 3] of the vehicle increases the size of the engine in the front-rear direction, which hinders downsizing of the engine. Therefore, the main plate (41) of the cooling fan (40) is moved in the centrifugal direction (vertical direction in FIG. 3).
It is conceivable to increase the size of the vane (42) in the centrifugal direction by expanding the vane (42).

[0004]

However, when the main plate (41) of the centrifugal cooling fan (40) is expanded in the centrifugal direction as described above, the crank plate (1) of the engine is moved by the main plate (41). 3 and the transistor-type magneto unit (18) disposed on the front surface of the crankcase (1). For this reason, the cooling air from the cooling fan (40) hits the front surface of the crankcase (1) and the transistor-type magneto unit (18) and the like, so that the front surface of the crankcase (1) and the like are sufficiently provided. No cooling. As a result, thermal distortion may occur on the front surface of the crankcase (1) or the like, and the transistor-type magneto unit (18) and the like may be deteriorated at an early stage due to heat.

SUMMARY OF THE INVENTION It is an object of the present invention to increase the amount of air blown by a centrifugal cooling fan and to allow sufficient cooling air to be sent from the cooling fan to a crankcase or the like. It is another object of the present invention to allow a cooling air from a centrifugal cooling fan to be sufficiently supplied to the ignition device even if the ignition device is arranged around the flywheel. further,
An object of the present invention is to prevent interference between an ignition device and a centrifugal cooling fan. Another object of the present invention is to make it possible to easily attach and detach the ignition device.

[0006]

Means for Solving the Problems [Invention of claim 1] The invention of claim 1 is, for example, shown in FIG.
As shown in FIG. 2 and FIG. 2, the configuration is as follows. A plurality of vanes (8) are arranged on a main plate (7) of a centrifugal cooling fan (6), and the main plate (7) is coaxially stacked on one end face (3a) of an engine flywheel (3). The centrifugal cooling fan of the engine fixed in the
(8) is provided so as to protrude in the centrifugal direction from the peripheral edge of the main plate (7).

[Invention of claim 2] The invention of claim 2 is the same as the above-mentioned invention of claim 1, but further configured as follows. An ignition device (18) for igniting with a spark plug is arranged to face the periphery of the flywheel (3).

[Invention of claim 3] Further, the invention of claim 3 is the same as the above-mentioned invention of claim 2, but further configured as follows. Of the protruding vane portions (8a) of the vanes (8) protruding from the periphery of the main plate (7), a portion (8b) that interferes with the ignition device (18) is cut away.

[Invention of Claim 4] The invention of Claim 4 is the same as that of Claim 2 or 3, but further configured as follows. A fixing device (19) for fixing the ignition device (18) to the engine is configured to be detachable via a protruding vane portion (8a) (8a) of an adjacent vane (8).

[0010]

Operation and Effect of the Invention [Claim 1] The invention of the above-mentioned claim 1 has the following operation and effects as shown in FIGS. 1 and 2, for example. Since the vane (8) of the centrifugal cooling fan (6) projects in the centrifugal direction from the periphery of the main plate (7) of the cooling fan (6), the vane is extended by the amount of the projecting vane portion (8a).
(8) becomes large and the amount of air blow increases. In addition, the size of the engine increases in the axial direction of the cooling fan (6) by the amount that the vane (8) does not need to be increased in the axial direction of the cooling fan (6) to increase the blowing amount. Can be suppressed. As a result, it is possible to achieve both an increase in the amount of air flow and a reduction in the size of the engine.

Further, since only the vane (8) is enlarged without increasing the size of the main plate (7), the main plate (7) does not have to protrude from the flywheel (3). Therefore, the main plate
The crankcase (1) in which the flywheel (3) is arranged so that (7) does not protrude from the flywheel (3).
, Or a member disposed on one side of the crankcase (1), and the like, so that air can be easily blown from the vane (8).
As a result, one side surface of the crankcase (1), the members, and the like are sufficiently cooled, and the heat distortion and early deterioration of the members and the like due to heat can be reliably reduced.

[Claim 2] The invention of claim 2 provides the following functions and effects in addition to the functions and effects of the invention of claim 1.
It works. Ignition device (1) around flywheel (3)
8) Even when the cooling fan is
The ignition device (18) is not covered by the main plate (7) to the extent that the main plate (7) of (6) does not protrude from the flywheel (3). Therefore, it becomes easy to blow air from the vane (8) to the ignition device (18), and the ignition device (18) is sufficiently cooled, so that early deterioration of the ignition device (18) due to heat can be reliably reduced.

[Claim 3] The third aspect of the present invention provides the following functions and effects in addition to the functions and effects of the second aspect of the invention.
It works. Since the protruding vane portion (8a) of the vane (8) has a cut-out portion (8b) that interferes with the ignition device (18),
The contact between each vane (8) and the ignition device (18) can be reliably prevented. Therefore, each vane (8) can be extended longer in the centrifugal direction of the cooling fan (6) as much as each vane (8) does not come into contact with the ignition device (18), and the blower volume can be more reliably increased. Can be.

[Claim 4] The invention of claim 4 has the following functions and effects in addition to the functions and effects of the invention of claim 2 or 3. By inserting a tool between the projecting vane portions (8a) of the adjacent vanes (8) and attaching / detaching a fixture (19) for fixing the ignition device (18) to the engine, the cooling fan (6) can be connected to a flywheel. The ignition device (18) can be detached from the engine without removing it from (3). Therefore,
It is possible to reduce the trouble when attaching and detaching the ignition device (18) from the engine for maintenance or the like.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a centrifugal cooling fan for an engine according to the present invention will be described below with reference to FIGS. FIG. 1 is an end view of the centrifugal cooling fan, and FIG. 2 is a longitudinal sectional view showing a main part of the cooling fan.

FIG. 2 shows the crankcase (1) of the engine.
As shown in the figure, the crankshaft (2) is rotatably supported, and the flywheel (3) is prevented from rotating at one end (right side in FIG. 1) of the crankshaft (2) by the key (4). Connected in state. One end surface (3a) of the flywheel (3)
On the right side in FIG. 2, a centrifugal cooling fan (6) is fixed in a coaxially stacked state. The cooling fan
(6) is covered by a fan cover (not shown). The centrifugal cooling fan (6) includes a main plate (7) and a plurality of vanes (8) radially arranged on one end surface (7a) of the main plate (7) [right side in FIG. Reference]. A through hole (10) is formed in the center of the main plate (7) [see FIG. 1].
The end of (2) and a boss (9) protruding from the flywheel (3) are penetrated.

Then, one end surface of the flywheel (3)
(3a) and the pulley (13) for the recoil starter sandwich the main plate (7) of the cooling fan (6) with the nut
When the cooling fan (6) is tightened, the cooling fan (6) is connected to the one end face (3) of the flywheel (3) via the pulley (13).
Pressed and fixed to a). The boss (9) stops the pulley (13) from rotating by fitting into the locking hole (13a) of the pulley (13).

A magnet (16) is fixed to the periphery of the flywheel (3).
A transistor type magneto unit [ignition device] (18) is arranged to face the periphery of (3). The transistor type magneto unit (18) is connected to an engine crankcase (1) by two mounting bolts [fixing tools] (19) shown in FIG.
Attached to one side. Then, an ignition plug (not shown) of the engine is ignited based on the detection of the magnet (16) by the transistor type magneto unit (18).

Next, a detailed configuration of the centrifugal cooling fan (6) will be described. That is, the main plate (7) of the cooling fan (6) is set to be substantially equal in size to one end surface (3a) of the flywheel (3).
(7) does not protrude from the periphery of the flywheel (3). On the other hand, the cooling fan (6)
Each of the vanes (8) is configured to project in the centrifugal direction from the peripheral edge of the main plate (7). The protruding vane portion (8) of each vane (8) protruding from the main plate (7)
In (a), a portion (8b) that interferes with the transistor-type magneto unit (18) is notched.

That is, the projecting vane portion (8) of each vane (8)
Since a) protrudes in the centrifugal direction from the periphery of the main plate 7 of the cooling fan 6, the size of the protruding vane portion 8a increases the size of the vane 8 and the amount of air blow. Moreover, since the main plate (7) does not protrude from the flywheel (3), one side surface of the crankcase (1) and the transistor type magneto unit (18) are not covered by the main plate (7). Also, the protruding vane portion (8a) of each vane (8)
Is a transistor-type magneto unit (18) and the transistor-type magneto unit (18)
Since the portion (8b) that interferes with the mounting bolt (19) to be mounted on the vehicle is cut off, each vane (8) does not reliably come into contact with the transistor-type magneto unit (18) or the mounting bolt (19).

Further, a tool is inserted between the projecting vane portions (8a) of the adjacent vanes (8) to loosen the two mounting bolts (19) or to loosen the two mounting bolts (19).
[Refer to FIG. 1], the transistor-type magneto unit (18) is connected to the crankcase (1) while the cooling fan (6) is attached to the flywheel (3).
Can be removed from.

The centrifugal cooling fan (6) is preferably made of a synthetic resin from the viewpoint of weight reduction and the like.
The invention is not limited to this, and may be made of, for example, a metal such as aluminum. Also, the main plate (7) and the vane
(8) may be integrally formed, or the main plate (7) and the vane (8) may be separately formed, and the vane (8) may be attached to the main plate (7).

Further, in the case where a rotation detection sensor for detecting the rotation speed of the crankshaft (2), for example, is provided opposite to the periphery of the flywheel (3),
The protruding vane portion (8a) of (8) forms the notch portion (8b) so as not to come into contact with the rotation detection sensor or the like. In the above description, the transistor-type magneto unit (18) is attached to the crankcase (1) with two mounting bolts (19). However, the present invention is not limited to this, and the transistor-type magneto unit (18) is not limited thereto. )
It may be attached to the crankcase (1) with one attachment bolt (19), or may be attached with three or more attachment bolts (19).

[Brief description of the drawings]

FIG. 1 shows an embodiment of a centrifugal cooling fan of an engine according to the present invention, and is an end view of the centrifugal cooling fan.

FIG. 2 is a longitudinal sectional view showing a main part of the cooling fan.

FIG. 3 is a longitudinal sectional view showing a main part of a conventional centrifugal cooling fan.

[Explanation of symbols]

3 ... flywheel, 3a ... one end face of flywheel, 6
... Centrifugal cooling fan, 7 ... Main plate of centrifugal cooling fan, 8
... Vane of centrifugal cooling fan, 8a ... Protruding vane part, 8b
... Notch of protruding vane part, 18 ... Transistor-type magneto unit [igniter], 19 ... Mounting bolt [fixture].

Claims (4)

[Claims] 1. A plurality of vanes (8) are arranged on a main plate (7) of a centrifugal cooling fan (6), and the main plate (7) is provided on one end surface (3a) of an engine flywheel (3). A centrifugal cooling fan for an engine, wherein the vanes (8) extend in a centrifugal direction from the peripheral edge of the main plate (7). Centrifugal cooling fan for the engine. 2. The centrifugal cooling fan for an engine according to claim 1, wherein an ignition device (18) for igniting with a spark plug is arranged opposite to a periphery of the flywheel (3). Features a centrifugal cooling fan for engines. 3. The centrifugal cooling fan for an engine according to claim 2, wherein the ignition device (18) includes a protruding vane portion (8a) of the vane (8) protruding from a peripheral edge of the main plate (7). A centrifugal cooling fan for an engine, wherein a part (8b) interfering with the cooling fan is cut off. 4. A centrifugal cooling fan for an engine according to claim 2, wherein a fixture (19) for fixing the ignition device (18) to the engine is provided.
A centrifugal cooling fan for an engine, characterized in that the fan can be attached and detached via the protruding vane portions (8a) (8a) of the adjacent vanes (8).