JPS6118676B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a recoil starter for a general-purpose engine.

A general-purpose engine equipped with a conventional recoil starter is shown in FIGS. 1 and 2. A fan cover 1 covers a cylinder 2 and a crankcase 3, a crankshaft 4 protrudes from the crankcase 3 into the fan cover 1, and a rotor 7 of a fan 5 and a generator 6 is pivotally attached to the crankshaft 4. At the same time, a coupling ring 8 protruding outward from the fan cover 1 is screwed onto the tip of the crankshaft 4. The starter cover 9 is screwed onto the outer periphery of the fan cover 1, covers the coupling ring 8, and protrudes outward from the fan cover 1. This starter cover 9 has a starter shaft 10 protruding inwardly to rotatably support a pulley 11, and a pulley rotating knob 12 attached to the pulley 11 with one end extending outward from the starter cover 9. A tension rope 13 is wound around the pulley 11.
A coil spring 14 is provided to reverse the rotation. Then, the claws 15 provided retractably on the pulley 11 are removably engaged with the engagement holes 16 of the coupling 8, and the rotation of the pulley 11 due to the tension of the rope 13 is transmitted to the crankshaft 4 via the coupling 8.
It has come to be transmitted to

In this way, the conventional recoil starter is assembled so as to bulge out from the fan cover that houses the generator (electrical component) and fan. That is, the above-mentioned coupling ring is necessary and has a relatively large width because the rope is wound directly around the outer periphery to start the motor when the claw 15 is broken or when a recoil starter is not installed. Further, since the bulge is relatively large, it is inconvenient for installation in a narrow place, transportation, etc.

In addition, as a recoil starter for this type of engine, Japanese Patent Application Laid-Open No. 48-59232 and Utility Model Application No. 52-
The one described in Publication No. 139947 is known. In the prior art example described in Japanese Patent Application Laid-Open No. 48-59232, a pulley, a crimping plate, and a disc spring are rotatably supported on a crank casing protrusion, and when a rope is pulled and the pulley is rotated, the crimping plate is supported on the crank casing protrusion by frictional force via a disc spring, so the inclined surface in the annular groove of the crank contacts the cam of the crimping plate, and the cam of the crimping plate slides onto the inclined surface, resulting in crimping. The plate moves toward the starting member against the pressing force of the disc spring, and the friction lining of the crimp plate and the edge of the starting member are frictionally connected, resisting the frictional force between the crimp plate, the disc spring, and the crank casing protrusion. By rotating the pressure bonding plate and the disc spring, the starting member rotates, and the crankshaft rotates to start the engine. Therefore, if the pressing force of the disc spring, the friction force between the disc spring and the crimp plate, and the crank casing protrusion, and the friction coefficient of the friction lining are not well balanced, the cam of the crimp plate will come into contact with the inclined surface of the pulley. , the crimp plate may rotate before the crimp plate moves toward the starter member and the friction lining of the crimp plate and the edge of the starter member are frictionally coupled, making it impossible to rotate the starter member and making it impossible to start. There is.

On the other hand, in the prior art example described in Japanese Utility Model Application Publication No. 52-139947, when the operating knob is pulled, the reel is rotated via the rope, and the support plate supporting the ratchet pawl is also rotated, and at this time, the reel is rotated through the rope. Since the movement plate moves slowly due to friction, the ratchet pawl stands up and engages with a ratchet gear carved into the flywheel fan, turning the crankshaft and starting the engine. However, with this configuration, if the friction force of the friction plate is not set appropriately, if the friction force is too small,
The friction plate does not move slowly relative to the support plate, and the ratchet pawl does not stand up. Also, if the frictional force of the friction plate is too large, the ratchet pawl may be damaged by the friction plate, making it impossible to start. There is a risk that this may occur.

The present invention has been made in view of the above-mentioned points, and provides a general-purpose air-cooled engine in which a fan is pivotally attached to a crankshaft protruding from the side surface of the crankcase, and the fan is covered with a fan cover to cool the engine. A cylindrical shaft portion is provided between the crankshaft and the fan, and is fixed to the crankcase through the crankshaft. A recoil starter pulley having a mating portion is screwed onto the shaft portion, the recoil starter pulley is connected to the crankcase side via a spring, and an engaging means is provided for engaging and disengaging the recoil starter pulley and the fan. . With this configuration, the starter operates reliably without becoming unable to start, there is no need to set frictional force, there is no need for the crimp plate, disc spring, or friction plate, and there is no need to use a conventional crankshaft. Compared to the recoil starter that protrudes outside the fan cover, there is no need for a coupling, a starter shaft, a starter cover, etc., and the cost can be significantly reduced.In addition, the recoil starter does not protrude toward the outside of the fan cover, making it easier to operate the engine. The purpose is to provide a recoil starter for a general-purpose engine that can be made compact.

Next, a first embodiment of the present invention will be described with reference to FIGS. 3 to 6.

The fan bag 21 covers the cylinder 22 and the crankcase 23. A crankshaft 24 is projected from the crankcase 23 into the fan cover 21, and the fan 25 and the rotor 27 of the generator 26 are attached to the crankshaft 24 inside the fan cover. is attached to the shaft. The shaft portion 28 is formed into a cylindrical shape by protruding from the side surface of the crankcase 23 located inside the fan cover 21 in the axial direction of the crankshaft, and penetrates the crankshaft 24 at the center in the axial direction. is the above fan 25
facing the inner side of

The shaft portion 28 has a quick thread 29 formed on its outer circumferential surface, and an engaging portion 3 provided on the inner circumferential surface of the pulley 30.
1 is screwed onto this quick screw 29, and a pulley 30 is screwed so that it can reciprocate in the axial direction along the quick screw 29 while rotating forward and backward. A tension rope 32 is wound around the pulley 30 to cause the pulley to move forward along the quick screw 29 while rotating the pulley.
One end is fixed to the pulley 30, and the other end extends outside the fan cover 21 and has a knob 33 attached thereto. The pulley 30 has a shaft 34 on the crankcase side.
One end of a coil spring 36, the other end of which is fixed to a coil spring housing 35, is fixed to this shaft 34. The coil spring storage portion 35 is formed integrally with the crankcase 23.

The pulley 30 has a pin 37 protruding from the surface facing the fan, and the fan 25 has a pin insertion hole 38 on the surface facing the pulley.
, so that the pin 37 of the pulley 30 engages in the engagement hole 38 of the fan 25 when the pulley 30 moves forward. In the figure, 39 is a piston, 40 is a connecting rod, 41 is a crank, 42 is an output shaft, 43 is an air cleaner, 44 is a muffler, and 45 is a pulley stopper.

Next, the operation of the recoil starter of the present invention will be explained.

The rope 32 is connected to the coil spring 36 through the knob 33.
By pulling it toward you against the urging force of
While the pulley 30 rotates, the quick screw 29 of the shaft portion 28
The pin 37 of the pulley 30 engages the engagement hole 38 of the fan 25, and the rotational force of the pulley 30 is transmitted to the fan 25, causing the crankshaft 24 to rotate. When you finish pulling the rope 32 and release your hand, the pulley 30 will release the coil spring 3.
Since one end of 6 is fixed via the shaft 34,
Due to the restoring force of the coil spring 36, the fan 25 moves back along the fast screw 29 of the shaft portion 28 while being reversed.
The pin 37 of the pulley 30 is disengaged from the engagement hole 38 and returns automatically. Pin 37 and insertion hole 3
A plurality of 8 are provided. The stopper 45 of the pulley 30 is set to prevent the recoil starter pulley from stopping rotating due to pressure contact between the side surface of the fan 25 and the pin 37.

Further, since the cylindrical shaft portion 28 is provided from the crankcase 23 so as to cover the outside of the rotor 27 of the fan 25, the recoil starter as a whole does not protrude outward significantly and can be configured compactly.

What is shown in FIG. 7 is a second embodiment of the present invention. In this embodiment, a friction plate 47 with a built-in spring 46 is disposed on the surface of the recoil starter pulley 30 facing the fan, and when the recoil starter pulley 30 moves forward along the quick screw 29, the friction plate 47 with the built-in spring 46 It is pressed against the fan 25 and rotates the fan 25.

What is shown in FIG. 8 is a third embodiment of the present invention. In this embodiment, the recoil starter pulley 30
A conventional claw 48 shown in FIG. 1 is disposed on the fan side of the engaging portion 4, and this claw 48 is engaged with the fan side.
9 was formed.

In this way, the present invention does not require any configuration of the engaging portion of the pulley 30 and the engaging portion of the fan 25, and the shaft portion 28 to which the pulley 30 is threaded is not necessarily formed integrally with the crankcase 23, but is separate from the crankcase 23. It may be formed from a member.

As explained above, according to the present invention, the operation of the starter is reliable, there is no risk that the starter will not be able to start, there is no need to set a frictional force, and there is no need to use a pressure bonding plate, a disc spring, or a friction plate. does not require. Furthermore, compared to conventional fan covers that protrude outside, the structure has fewer parts and is simpler, and there is no outward bulge on the fan cover, making the entire engine more compact. .

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a general-purpose engine equipped with a conventional recoil starter, FIG. 2 is a side view of the same, and FIG. 3 is a cross-sectional view showing a general-purpose engine equipped with a recoil starter according to a first embodiment of the present invention. 4 is an enlarged cross-sectional view of the same essential parts as above, FIG. 5 is a perspective view showing the fan, FIG. 6 is a side view of FIG. 3, and FIG. 7 is an important part showing the second embodiment of the present invention. FIG. 8 is a sectional view of a main part showing a third embodiment of the present invention. In the figure, 21 is a fan cover, 22 is a cylinder, 23 is a crankcase, 24 is a crankshaft, 25 is a fan, 28 is a shaft, 30 is a pulley, 32 is a rope, 36 is a coil spring, and 37 is an engagement of the pulley. 38 indicates an engaging portion of the fan.

Claims (1)

[Claims] 1. In a general-purpose air-cooled engine in which a fan is mounted on a crankshaft protruding from the side of the crankcase, and the engine is cooled by outside air introduced by covering the fan with a fan cover, a crankshaft is installed between the crankcase and the fan. A cylindrical shaft part penetrated through the center is provided extending from the crankcase side, and a quick thread is formed on the outer peripheral surface of the cylindrical shaft part,
A recoil starter pulley having an engaging portion that engages with the quick screw is screwed onto the quick screw on the outer periphery of the cylindrical shaft portion, and the recoil starter pulley is rotated by a spring along the quick screw toward the crankcase side. At the same time, a tension rope is wound around the outer periphery of the recoil starter pulley with one end thereof fixed to rotate the pulley toward the fan side along the quick screw;
Further, the recoil starter pulley and the fan are provided with an engaging means that engages with the recoil starter pulley when the recoil starter pulley rotates toward the fan, and disengages when the recoil starter pulley rotates toward the crankcase due to the spring. Recoil starter for general-purpose engines.