JPS6132136Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a recoil starter for a forced air-cooled engine, and an object thereof is to increase the amount of cooling air and improve the cooling performance of the engine.

Conventionally, in a forced air-cooled engine equipped with a recoil starter, as shown in FIG. the starting pulley 28 and fan 2 by starting the recoil starter 29.
The engine was started by applying rotation to the crankshaft 26 through the engine 7.

However, in this type of device, the recoil case 30 of the recoil starter 29 is installed to cover the air intake hole portion 32 of the fan case 31, and the cooling air is sucked in through the air intake window 33 on the circumferential surface of the recoil case 30. The cooling air generated becomes approximately U-shaped as shown by A in the figure, and the intake resistance is large, resulting in a decrease in engine cooling performance.

Furthermore, the width H' of the recoil case 30 of the recoil starter 29, which is attached to the front surface of the fan case 31 in a protruding manner, is increased due to the large air intake window 33 formed on its circumferential surface.
The distance L from the front wall of the engine 5 to the front end of the recoil case 30 becomes large, making it impossible to make the engine compact as a whole.

The present invention was proposed in order to solve the above-mentioned drawbacks, and is designed to allow outside air to be smoothly sucked into the centrifugal fan from the end face of the recoil case through the ventilation hole in the foil portion of the rope pulley.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of the forced air-cooled engine, and FIG. 2 is a sectional view taken along the line -- in FIG. In this engine E, a flan foil 3 is fixed to the shaft end 2a of the crankshaft 2 that protrudes from the front wall 1a of the crankcase 1, and the flywheel 3 is attached to the front surface 3 of the crankshaft 2.
A centrifugal fan 5 is constructed by forming fans 4 in a radial manner.

The centrifugal fan 5 is covered with a fan case 6. The fan case 6 has an air exhaust port 8 opened upward toward the cylinder block 7 of the engine E, and an air intake port 9 opened in front of the centrifugal fan 5. be.

Then, the recoil starter R is inserted toward the centrifugal fan 5 from outside the air intake port 9, and the recoil case 10 of the recoil starter R is inserted into the fan case 6.
is fixed to the front wall 6a of.

This recoil starter R is recoil case 1
0 from the center part 10b of the front end wall 10a to the pivot shaft 11
protrudes toward the crankshaft (rotating shaft) 2, and a recoil boss 12 is rotatably and rewindably supported on a pivot shaft 11 by a coil spring 13 provided at the rear thereof.

An output pawl 14 is pivotally supported at the rear of the coil spring 13 of the recoil boss 12, and the output pawl 14 protrudes outward only during the starting operation of the recoil starter R, and is an input engagement formed in a bar-shaped protrusion from the front surface of the centrifugal fan 5. It is adapted to engage with the portion 15 to transmit the starting rotational force.

An annular rope pulley 16 is integrally formed in the front part of the recoil boss 12, and a ventilation hole 18 is provided in the foil portion 17 of the rope pulley 16, as shown in FIG.
is formed.

The outer peripheral surface 12a of the recoil boss 12 is
The wind guide surface 19 has a small diameter at the front and widens toward the rear, and has a smooth rearward expansion.This air guide surface 19 serves as an outside air introduction path for cooling air generated by a centrifugal fan. B is formed.

That is, the outside air introduction path B sucks outside air with the centrifugal fan 5 from the outside air intake port 20 opened in the front end wall 10a of the recoil case 10 of the recoil starter R through the ventilation port 18 of the rope pulley 16, and guides it to the exhaust port 8 with the fan case 6. However, the air is formed so as to be blown from the exhaust port 8 toward the cylinder block 7 of the engine E.

The recoil case 10 attached to the front surface 6a of the fan case 6 only accommodates the rope pulley 16 portion of the recoil starter R therein, so its width H is made small.

Although not shown in the drawings, since the width H of the recoil case 10 is small, it is conceivable to form the recoil case 10 integrally when pressing the fan case 6.

In addition, the present invention also provides the output claw 1 of the recoil starter R.
The input engaging portion 15 with which the fan 4 engages is not limited to the one in which the input engaging portion 15 is formed to protrude from the front surface 3a of the centrifugal fan 5 in a rod shape;
The input engagement portion may be configured with a conventional recoil pulley.

In the figure, reference numeral 21 is a starter rope wound around the rope pulley 16 of the recoil starter R, and 22 is an operation knob attached to the tip of the starter rope 21, which is fixed to the circumferential surface 10c of the recoil case 10 when not in operation. It is adapted to be received and held by a receiver 23.

The present invention is configured and operates as described above, and thus has the following effects.

(b) Outside air is sucked in from the front of the recoil starter, smoothly guided by the wind guide surface on the outer circumferential surface of the recoil boss, and sucked into the centrifugal fan, so air intake resistance is small and the amount of cooling air supplied to the engine by the centrifugal fan is reduced. cooling performance.

(b) Furthermore, by simply storing the recoil pulley portion inside the recoil case attached to the fan case, the width H of the recoil case protruding from the fan case can be reduced, and the longitudinal length of the engine can be reduced.

(c) Also, since the width H of the recoil case can be reduced, the recoil case can be formed integrally with the fan case, and in this case, in addition to the above effects, the recoil case can be formed at low cost. be able to.

(d) Since the drive claw of the recoil starter approaches the front of the centrifugal fan, when forming the input engagement part with a protrusion formed protruding from the centrifugal fan, the conventional recoil pulley can be omitted, resulting in a simple structure and low cost. It can be implemented.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a schematic front view of a forced air-cooled engine, FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIG. 3 is a front view of the rope pulley and recoil boss. 4 are schematic side views showing a conventional example. E... Engine, B... Outside air introduction path, 1... Crank case, 2... Rotating shaft (crankshaft), 2
a... Front end of 2, 5... Centrifugal fan, 6... Fan case, 7... Cylinder block, 8... Air exhaust port, 9... Air intake port, 10... Recoil case,
10a... Front end wall of 10, 10b... Center part of 10, 11... Pivot shaft, 12... Recoil boss, 1
2a...outer peripheral surface of 12, 14...output claw, 15...
...Input engagement part, 16...Rope pulley, 17...
16 foil portion, 18...ventilation port, 19...air guide surface.

Claims (1)

[Scope of utility model registration request] A centrifugal fan 5 is disposed on the front side of the crankcase 1 of the forced air-cooled engine E, and the front end 2a of the rotating shaft 2 is
The centrifugal fan 5 is covered with a fan case 6, the air intake port 9 of the fan case 6 is opened at the front of the centrifugal fan, the air exhaust port 8 is opened toward the cylinder block 7, and the recoil case 10 is closed to the air intake port. Fan case 6 protrudes forward from 9.
A pivot shaft 11 is provided protruding from the center portion 10b of the front end wall 10a of the recoil case 10 toward the rotating shaft 2, and a recoil boss 12 is attached to the pivot shaft 11 so that the spring 1
3, the output claw 14 is rotatably supported for rewinding, and the output claw 14 is supported at the rear of the recoil boss 12.
is configured such that rotation can be transmitted to the input engagement part 15 fixed to the centrifugal fan only when it is swung into the output transmission position by centrifugal force, and a rope pulley 16 is fixed to the front part of the recoil boss 12. A ventilation port 18 is provided in the foil portion 17 of the recoil case 10, an outside air intake port 20 is provided in the front end wall 10a of the recoil case 10, and an outside air introduction path B is formed on the outer periphery of the recoil boss 12.
A recoil starter for a forced air-cooled engine, characterized in that a recoil starter for a forced air-cooled engine is formed in a smooth rearwardly widening air guide surface 19 which is narrow in diameter at the front and becomes larger toward the rear.