JP3812896B2 - Recoil starter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention rotates a rope reel by pulling a recoil rope, transmits the rotation of the rope reel to a cam via a damper spring, and engages a ratchet mechanism formed on a rotating member connected to the engine side with the cam. The present invention relates to a recoil starter that rotates a rotating member and starts the engine by the rotation of the rotating member.
[0002]
[Prior art]
Rotating members such as flywheel magnets on the engine side or driving pulleys via a ratchet mechanism such as a centrifugal clutch that is engaged with and disengaged from the cam by transmitting the rotation of the rope reel rotated by pulling the recoil rope. In the recoil starter designed to rotate, the damper spring wound in the shape of a coil spring is interposed between the front rope reel and the cam to elastically connect the two, and the rotation of the rope reel is cammed via the damper spring. There is already known a recoil starter having a structure in which a shock transmitted to a hand due to a change in load at the time of starting the engine is absorbed.
[0003]
For example, in the conventional recoil starter proposed in Japanese Patent Application No. 2002-144695, as shown in FIG. 7, a damper spring 34 is accommodated in annular recesses 32 and 33 formed on opposing surfaces of a rope reel 30 and a cam 31. One end portion 35 of the damper spring 34 bent in a U shape is accommodated in an engagement groove 36 formed in the rope reel 30, and the other end portion 37 bent in the axial direction is formed in the cam 31. The opening 38 is inserted into the opening 38. The rope reel 30 is rotated by pulling the rope 39 wound around the rope reel 30, the cam 31 is rotated via the damper spring 34, and the cam pawl 40 formed on the outer peripheral surface of the cam 31 and the engine By engaging with a ratchet 42 formed on a rotating member 41 attached to the crankshaft, rotation is transmitted to the rotating member 41 and the crankshaft is rotated. When the rotation of the cam 31 is blocked by the starting resistance of the engine, the damper spring 34 is twisted to buffer the impact on the rope reel 30, and at the same time, the rotational force of the rope reel 30 is fed to the damper spring 34. When the driving force of the rope reel 30 exceeds the starting resistance of the engine, the rotational force generated by the damper spring 34 is released, and the rotating member 41 is rotated via the cam 31 to start the engine. .
[0004]
[Problems to be solved by the invention]
The damper spring 34 interposed between the rope reel 30 and the cam wants to increase the buffer capacity and the animal power capacity as much as possible in terms of function. To increase these capacity, the wire diameter and winding diameter of the damper spring 34 are increased. Although it is possible to increase the diameter, in order to increase the wire diameter and the winding diameter of the damper spring 34, the dimensions of the annular recesses 32 and 33 accommodating the damper spring 34 must be set large. . In the prior art described above, as shown in FIGS. 8A and 8B, the cam pawl 40 is formed from the outer peripheral surface of the outer peripheral wall 43 of the annular recess 33 that accommodates the damper spring 34 formed in the cam 31. The ratchet 42 that protrudes and engages with the cam pawl 40 must also be provided in the outer peripheral direction of the rotating member 41 such as a drive pulley or a flywheel magnet. On the other hand, the size of the outer shape of the cam 31 is limited by the relationship with the rotating member 41 such as the drive pulley and the flywheel magnet, the cooling fan, the case 44 and the like. Accordingly, since the size of the annular recess 33 that accommodates the damper spring 34 is limited, setting the wire diameter and the winding diameter of the damper spring 34 large can be realized except for increasing the overall shape of the starter. It was difficult.
[0005]
The present invention solves the above-mentioned problems of the prior art, and can accommodate a damper spring having a large shock-absorbing performance and animal power capacity without increasing the overall outer shape, and can easily start the engine. It is an issue to provide.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, a recoil starter according to the present invention includes a rope reel around which a recoil rope is wound, a cam provided adjacent to the rope reel and engaged with a ratchet mechanism, a rope reel, and a cam. Through a ratchet mechanism provided on a rotating member attached to the crankshaft of the engine. In the recoil starter for starting the engine by transmitting to the rotating member, an annular recess for accommodating the damper spring is formed facing the joint surface between the rope reel and the cam, and the damper spring accommodated in the annular recess is Lock both ends of the rope reel and cam to the rope reel and cam. Furthermore, a plurality of openings are formed in the outer peripheral wall forming the annular concave portion of the cam at intervals in the circumferential direction, and the outer peripheral wall between the openings can be engaged with the ratchet mechanism. A cam claw is formed.
[0007]
According to a second aspect of the present invention, a flange portion projecting radially outward is integrally formed on one side of the outer peripheral wall forming the annular recess portion of the cam, and the inner peripheral edge of the flange portion and the annular recess portion are integrally formed. Both ends of the cam claw are connected to and supported by the bottom of the cam.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples shown in the drawings. As shown in FIG. 1, the recoil starter of the present invention pulls the handle 3 coupled to the end of the recoil rope 2 exposed to the outside of the case 1, thereby driving the drive unit accommodated in the case 1. Is connected to the crankshaft of the engine via a ratchet mechanism 10 that engages with a cam claw 11 formed on the outer peripheral surface of a cam 8 rotated by the rope reel 4. The rotating member 9 is rotated to start the engine.
[0009]
As shown in FIGS. 2 and 3, the rope reel 4 around which the recoil rope 2, one end of which is drawn out of the case 1, is wound and formed integrally with the case 1 inside the case 1. One end of a recoil rope 2 wound around the rope reel 4 is fixed to the rope reel 4, and the other end is pulled out to the outside of the case 1. A handle 3 for manually pulling the recoil rope 2 is coupled to the section. By pulling the handle 3, the recoil rope 2 is pulled out from the rope reel 4, and the rope reel 4 is driven to rotate about the support shaft 5.
[0010]
Between the side surface of the rope reel 4 and the inner wall surface of the case 1, the rope reel 4 rotated by pulling the recoil rope 2 is rotated in the reverse direction, and the drawn recoil rope 2 is wound around the rope reel 4. A recoil spring 6 for returning is disposed. One end of the recoil spring 6 is fixed to the case 1 and the other end of the outer periphery is fixed to the rope reel 4. When the rope reel 4 is rotated by pulling the recoil rope 2. The recoil rope 6 is rotated to the rope reel 4 by rotating the rope reel 4 in the reverse direction with the rotational force accumulated in the recoil spring 6 by releasing the recoil rope 2. Operates to rewind.
[0011]
A cam 8 for transmitting the rotation of the rope reel 4 to the crankshaft side of the engine is disposed adjacent to the rope reel 4 on the end surface of the support shaft 5 formed in the case 1 and is rotatably attached by screws 22. . The cam 8 is formed with a plurality of cam claws 11 engaged with and disengaged from the ratchet mechanism 10 formed on the rotating member 9 connected to the crankshaft of the engine. By engaging with the ratchet mechanism 10, the rotation on the cam 8 side is transmitted to the crankshaft of the engine via the rotating member 9. The ratchet mechanism 10 of this embodiment is configured as a centrifugal clutch. After the engine is started, the rotating member 9 is rotated by the engine so that the ratchet mechanism 10 is separated from the cam pawl 11 by centrifugal force. By rotating, the rotation transmission between the engine side and the cam 8 side is interrupted.
[0012]
Annular recesses 12 and 13 are formed on opposite sides of the rope reel 4 and the cam 8 so as to face each other, and the rope reel 4 and the cam 8 are rotationally connected in the annular recesses 12 and 13. A damper spring 14 is accommodated. As shown in FIG. 4, the damper spring 14 is formed in the shape of a torsion coil spring, and a locking end 15 obtained by bending the end bent in the horizontal direction into a U shape is formed on one end of the damper spring 14. Is formed. The locking end 15 is accommodated in a locking groove 16 formed continuously with the annular recess 12 on the outer peripheral side of the annular recess 12 of the rope reel 4 so that the rope reel 4 and the damper spring 14 rotate in the rotational direction. Connected to A locking end 17 bent in the axial direction is formed on the other end side of the damper spring 14, and the locking end 17 extends from the groove bottom of the annular recess 13 of the cam 8 to the cam 8. The other end side of the damper spring 14 is rotationally connected to the cam 8 by being inserted into a locking hole 18 formed so as to penetrate the upper surface side.
[0013]
Inner circumferential surfaces of the annular recesses 12 and 13 formed in the rope reel 4 and the cam 8 form boss portions 19 and 20, respectively, and the outer diameters of the boss portions 19 and 20 are the same. The damper spring 14 is arranged so that the abutting portion of the end faces of the boss portions 19 and 20 of the two is substantially in the center of the winding portion of the damper spring 14. When a predetermined rotational force is applied to 14, the winding portion of the damper spring 14 is almost uniformly wound around the outer peripheral surfaces of the boss portions 19 and 20 of the rope reel 4 and the cam 8, so that a further damper spring is obtained. 14 elastic deformation is suppressed and the maximum stress is limited.
[0014]
As shown in FIGS. 4 to 6, the cam 8 is integrally formed with a flange portion 23 projecting radially outward on one side of the outer peripheral wall 26 forming the annular recess 13. The outer peripheral wall 26 is cut at a plurality of locations at intervals in the circumferential direction to form openings 27 penetrating the inside of the annular recess 13 and the outer side of the outer peripheral wall 26, and the peripheral wall 26 is not cut off in the circumferential direction. A plurality of cam claws 11 are formed in a dispersed manner. Both ends of the outer peripheral wall 26 forming the cam claw 11 are connected by the inner peripheral edge of the flange portion 23 and the groove bottom portion 28 of the annular recess 13, and the damper spring 14 is accommodated and supported by the inner side surface of the cam claw 11. At the same time, the engagement surface 29 facing the circumferential direction of the cam claw 11 engages with the ratchet mechanism 10 to transmit the rotation of the cam 8 to the rotating member 9 side via the ratchet mechanism 10.
[0015]
Further, as shown in FIGS. 4 and 5, each cam claw 11 of the cam 8 has an engagement surface 29 that is perpendicular to the circumferential direction that can engage with the ratchet mechanism 10. Are formed at both ends. Further, as shown in FIG. 4, the locking groove 16 for receiving the locking end 15 of the damper spring 14 formed in the annular recess 12 for receiving the damper spring 14 of the rope reel 4 is also symmetrical in the circumferential direction. It is formed, and it can be adapted to an engine with a reverse rotation direction by changing to a damper spring having a different winding direction.
[0016]
The rope reel 4 is assembled to the support shaft 5 formed in the case 1, one end side of the damper spring 14 is locked in the locking groove 16 of the rope reel 4, and is attached to the boss portion 19 of the rope reel 4, The cam 8 is overlapped with the side surface of the rope reel 4 so that the locking end 17 on the other end side of the damper spring 14 is inserted into the locking hole 18 formed in the cam 8, and a screw is attached to the tip of the support shaft 5. The cam 8 and the rope reel 4 are assembled to the case 1 by fastening 22. The center of the cam 8 is rotatably supported with respect to the support shaft 5 by the base side of the screw 22, and the outer peripheral edge of the flange portion 23 is rotatably supported by the annular recess 25 of the rope reel 4. The inclination of the cam 8 due to the unbalanced load acting on the cam 8 is suppressed, and the destruction of the cam 11 due to the unbalanced load is prevented.
[0017]
The operation of the recoil starter of the above embodiment will be described. Before the engine starting operation, the ratchet mechanism 10 formed on the rotating member 9 connected to the crankshaft of the engine is in the state of being moved inward by the action of a spring, and the cam pawl 11 formed on the cam 8 It is arranged at the position where it touches. When the recoil rope 2 is pulled, the rope reel 4 is rotated, and the cam 8 is rotated via the damper spring 14 integrally therewith. The cam claw 11 of the cam 8 contacts the ratchet mechanism 10 to rotate the rotating member 9 via the ratchet mechanism 10 and the crankshaft connected to the rotating member 9 is rotated. As a result, the rotational load is increased and the rotational load of the cam 8 is increased. However, the damper spring 14 is twisted to absorb this load, so that the impact is not directly transmitted to the recoil rope 2 side.
[0018]
When the damper spring 14 is twisted, the rotational force on the rope reel 4 side is accumulated in the damper spring 14. When the damper spring 14 is twisted, the outer diameter of the winding portion of the damper spring 14 is reduced and wound on the outer peripheral surfaces of the boss portions 19 and 20 formed on the rope reel 4 and the cam 8, so that the damper spring 14 has no more. The stress of no longer acts. When the winding portion of the damper spring 14 is uniformly wound around the boss portions 19 and 20, the rope reel 4 and the cam 8 are integrally connected by the damper spring 14 by the action of the spring clutch, and the rope reel 4 is rotated. Directly transmitted to the cam 8.
[0019]
At this time, an eccentric load acts on the cam 8 between the ratchet mechanism 10 engaged with the cam claw 11 and the locking hole 18 supporting the damper spring 14. Since the outer peripheral edge portion of the flange portion 23 that is supported and has a large diameter is supported by the side surface of the rope reel 14, the tilt deformation of the cam 8 due to the uneven load is suppressed.
[0020]
Further, when the rope reel 4 is rotated and the rotational force exceeds the starting resistance of the engine, the rotational force of the rope reel 4 caused by the pulling of the recoil rope 2 and the rotational force stored in the damper spring 14 are released to the cam 8 side. Therefore, the crankshaft of the engine is rotated at a stroke and the engine is started. When the engine is started and the crankshaft is rotated, the ratchet mechanism 10 is rotated outward by the action of centrifugal force and detached from the cam claw 11 of the cam 8 so that the rotation of the engine is not transmitted to the cam 11 side. When the recoil rope 2 is loosened after the engine is started, the rope reel 4 is rotated in the reverse direction by the rotational force accumulated in the recoil spring 6 and the recoil rope 2 is rewound onto the rope reel 4.
[0021]
【The invention's effect】
As described above, according to the present plan, the outer peripheral wall of the annular recess that accommodates the damper spring formed in the cam is partially cut to form an opening, and the cam pawl is formed by the remaining outer peripheral wall that is not cut. Therefore, there is no need to form a cam claw that protrudes outside the outer peripheral wall forming the annular recess, and the outer peripheral wall of the annular recess can be formed on the outer side accordingly, The outer diameter of the annular recess can be set large without increasing the outer shape, and a damper spring with a large linearity and winding diameter can be accommodated in this annular recess, and therefore buffering without increasing the outer shape of the recoil starter -It is possible to increase the power storage capacity and provide a recoil starter that can be easily operated.
[0022]
In addition, when the same damper spring as before is used, the outer shape of the cam can be made small, and a rotating member such as a flywheel magnet or a driving pulley arranged on the outer periphery of the cam or a case for housing these Can be designed more compactly, and a small and light recoil starter can be provided.
[0023]
Furthermore, according to the invention of claim 2, a flange portion projecting radially outward is integrally formed on the edge of the outer peripheral wall forming the annular recess of the cam, and both ends of the cam claw are connected to the bottom of the annular recess. Since both ends of the cam claw are supported by being continued to the inner peripheral edge of the flange portion, deformation due to engagement of the cam claw with the ratchet mechanism is prevented.
[Brief description of the drawings]
FIG. 1 is a front view of a recoil starter according to an embodiment of the present invention. FIG. 2 is a front view of the same recoil starter as FIG. 1 with a rotating member removed. FIG. 4 is a perspective view of the rope reel, damper spring and cam of the embodiment of FIG. 1. FIG. 5 is a plan view of the cam employed in the embodiment. FIG. 6 is the same as FIG. Fig. 7 is a vertical sectional side view of a conventional recoil starter. Fig. 8 is a perspective view of a cam employed in a conventional recoil starter, and Fig. 7 is a vertical sectional view of a state in which a damper spring is accommodated. Side view [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case 4 Rope reel 8 Cam 9 Rotating member 10 Ratchet mechanism 11 Cam claw 12 Annular recessed part 13 Annular recessed part 14 Damper spring 23 Flange part 25 Annular recessed part 26 Outer peripheral wall 27 Opening 28 Bottom part 29 Engagement surface

Claims (2)

Drive unit by a rope reel wound with a recoil rope, a cam provided with a cam claw disposed adjacent to the rope reel and engaged with a ratchet mechanism, and a damper spring interposed between the rope reel and the cam The recoil is configured to start the engine by transmitting the rotational force on the side of the disturbance section that is rotationally driven by pulling of the recoil rope to the rotating member via a ratchet mechanism provided on the rotating member attached to the crankshaft of the engine In the starter, an annular recess for accommodating the damper spring is formed on the joint surface between the rope reel and the cam so as to oppose each other, and both ends of the damper spring accommodated in the annular recess are respectively engaged with the rope reel and the cam. The rope reel and cam are connected via a damper spring, and an annular recess is formed in the cam. Recoil starter in the outer peripheral wall at intervals in the circumferential direction to form a plurality of openings, and wherein the outer peripheral wall between the opening to the formation of the ratchet mechanism engageable with the cam claws that. A flange portion projecting radially outward is integrally formed on one side of the outer peripheral wall forming the annular recess of the cam, and both ends of the cam pawl are formed on the inner peripheral edge of the flange portion and the bottom of the annular recess. The recoil starter according to claim 1, wherein the starter is connected and supported.

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