JP2004084641A - Recoil starter - Google Patents

Abstract

A recoil starter capable of accommodating a damper spring (14) having a large buffering performance and a large animal power without increasing the overall outer shape.
A recoil starter that rotates a rope reel and a cam by pulling a recoil rope and transmits the rotation of the cam to an engine via a ratchet mechanism to start the rope reel and the cam. Annular concave portions 12 and 13 for accommodating the damper springs 14 are formed on the joint surface, and the rope reel 4 and the cam 8 are connected by the damper springs 14 contained in the annular concave portions 12 and 13. A plurality of openings 27 are formed on the outer peripheral wall 26 forming the recess 13 at intervals in the circumferential direction, and the outer peripheral wall 26 between the openings 27 forms the cam claws 11 engageable with the ratchet mechanism 10. .
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, the rope reel is rotated by pulling the recoil rope, the rotation of the rope reel is transmitted to the cam via a damper spring, and a ratchet mechanism formed on a rotating member connected to the engine is engaged with the cam. The present invention relates to a recoil starter that rotates a rotating member in combination and starts an engine by the rotation of the rotating member.
[0002]
[Prior art]
The rotation of the rope reel, which is rotated by pulling the recoil rope, is transmitted to a cam, and further, a rotating member such as a flywheel magnet or a driving pulley on the engine side via a ratchet mechanism such as a centrifugal clutch disengaged from the cam. In the recoil starter, the damper spring wound in the form 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 controlled by the cam through the damper spring. There is already known a recoil starter having a structure in which a shock transmitted to a hand due to a load fluctuation or the like at the time of engine start is absorbed to transmit the shock to the hand.
[0003]
For example, in a conventional recoil starter proposed in Japanese Patent Application No. 2002-146995, as shown in FIG. 7, a damper spring 34 is housed in annular concave portions 32 and 33 formed on opposing surfaces of a rope reel 30 and a cam 31. The U-shaped one end 35 of the damper spring 34 is housed in an engagement groove 36 formed in the rope reel 30, and the other end 37 bent in the axial direction is formed on the cam 31. The opening 38 is inserted through the opening 38. By pulling the rope 39 wound around the rope reel 30, the rope reel 30 is rotated, the cam 31 is rotated via a damper spring 34, and the cam claw 40 formed on the outer peripheral surface of the cam 31 and the engine are rotated. The rotation is transmitted to the rotating member 41 by the engagement with the ratchet 42 formed on the rotating member 41 attached to the crankshaft, and the crankshaft is rotated. When the rotation of the cam 31 is prevented by the engine starting resistance, 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 applied to the damper spring 34. When the driving force of the rope reel 30 exceeds the starting resistance of the engine, the damping spring 34 releases the rotating force 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 is required to have as large a buffering capacity and a capacity as possible in terms of its function. To increase these capabilities, the wire diameter and winding diameter of the damper spring 34 must be increased. Although it is possible to increase the diameter, the outer diameter of the annular recesses 32, 33 accommodating the damper spring 34 must be set larger in order to increase the wire diameter and the winding diameter of the damper spring 34. . In the above-mentioned conventional technique, as shown in FIGS. 8A and 8B, a cam claw 40 is formed from an outer peripheral surface of an outer peripheral wall 43 of an annular concave portion 33 that accommodates a damper spring 34 formed on the cam 31. The ratchet 42, which is formed to protrude and engages with the cam pawl 40, must be provided on the outer peripheral side of the rotating member 41 such as a drive pulley or a flywheel magnet. On the other hand, the outer size 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. Therefore, since the size of the annular recess 33 accommodating the damper spring 34 is limited, setting the wire diameter and the winding diameter of the damper spring 34 to be large can be realized except for increasing the entire shape of the starter. It was difficult.
[0005]
SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and can accommodate a damper spring having a large buffering performance and a large animal power without increasing the overall outer shape, and can easily start an engine. The task is to provide
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a recoil starter according to the present invention includes a rope reel wound with a recoil rope, a cam provided with a cam claw disposed adjacent to the rope reel and engaging with a ratchet mechanism, a rope reel and a cam. And a damper spring interposed therebetween, and a driving force is formed on a rotating member mounted on a crankshaft of an engine through a ratchet mechanism provided on a rotating member mounted on a crankshaft of the engine, the driving force being generated by the recoil rope being driven by rotation of the recoil rope. In the recoil starter for starting the engine by transmitting the damper spring to the rotating member, an annular recess for accommodating a damper spring is formed on the joint surface between the rope reel and the cam, and the damper spring accommodated in the annular recess is formed. Attach both ends to the rope reel and cam, respectively, and connect the rope reel and cam to the damper spring. And a plurality of openings are formed at intervals in the circumferential direction on an outer peripheral wall forming an annular concave portion of the cam, and the outer peripheral wall between the openings allows engagement with the ratchet mechanism. A cam claw is formed.
[0007]
The invention according to claim 2 is characterized in that a flange portion projecting radially outward is integrally formed on one side of an outer peripheral wall forming an annular concave portion of the cam, and an inner peripheral edge of the flange portion and the annular concave portion are formed. Characterized in that both ends of the cam pawl are connected and supported at the bottom of the cam pawl.
[0008]
BEST MODE FOR CARRYING OUT 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 a handle 3 coupled to an end of a recoil rope 2 exposed to the outside of a case 1, thereby driving a driving unit housed in the case 1. Is connected to the crankshaft of the engine via a ratchet mechanism 10 which engages with a cam pawl 11 formed on the outer peripheral surface of the 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, a rope reel 4 wrapping a recoil rope 2 having one end pulled out of the case 1 is formed integrally with the case 1 so as to protrude 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 of the case 1 to be rotatably supported by a support shaft 5. A handle 3 for manually pulling the recoil rope 2 is connected to the portion. 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 opposite direction, and the pulled recoil rope 2 is wound around the rope reel 4. A recoil spring 6 for returning is arranged. One end on the inner peripheral side of the recoil spring 6 is fixed to the case 1 and the other end on the outer peripheral side is fixed to the rope reel 4. When the recoil rope 2 is pulled to rotate the rope reel 4, When the recoil spring 6 releases the recoil rope 2, the recoil rope 6 is released to rotate the rope reel 4 in the reverse direction with the rotational force stored in the recoil spring 6, and the recoil rope 2 is transferred to the rope reel 4. 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 on an end face of the support shaft 5 formed in the case 1, adjacent to the rope reel 4, and rotatably attached by a screw 22. . The cam 8 has a plurality of circumferentially extending cam claws 11 which are engaged with and disengaged from a ratchet mechanism 10 formed on a rotating member 9 connected to the crankshaft of the engine. By engaging with the ratchet mechanism 10, the rotation of the cam 8 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. It turns and transmission of rotation between the engine side and the cam 8 side is interrupted.
[0012]
Annular concave portions 12 and 13 are respectively formed on the opposing side surfaces of the rope reel 4 and the cam 8 so as to oppose each other, and the rope reel 4 and the cam 8 are rotationally connected in the annular concave portions 12 and 13. The damper spring 14 is housed. As shown in FIG. 4, the damper spring 14 is formed in the shape of a torsion coil spring, and at one end side of the damper spring 14, a locking end 15 obtained by bending a horizontally bent end into a U-shape is provided. Is formed. The locking end portion 15 is accommodated in a locking groove 16 formed on the outer peripheral side of the annular concave portion 12 of the rope reel 4 so as to be continuous with the annular concave portion 12 so that the rope reel 4 and the damper spring 14 rotate in the rotation direction. Linked to A locking end 17 bent in the axial direction is formed on the other end of the damper spring 14. 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 of the damper spring 14 is rotatably connected to the cam 8 by being inserted into a locking hole 18 formed to penetrate the upper surface.
[0013]
The 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 formed to be the same. The damper spring 14 is arranged so that the abutting portion of the end surfaces of the boss portions 19 and 20 is substantially at the center of the winding portion of the damper spring 14. When a predetermined rotational force is applied to the rope 14, the winding portion of the damper spring 14 is almost evenly wound around the outer peripheral surfaces of the bosses 19 and 20 of the rope reel 4 and the cam 8. 14 is restrained from elastic deformation 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 that protrudes radially outward on one side of an outer peripheral wall 26 that forms the annular concave portion 13. The outer peripheral wall 26 is cut at a plurality of locations at intervals in the circumferential direction to form an opening 27 that penetrates the inside of the annular concave portion 13 and the outside of the outer peripheral wall 26, and is formed in the circumferential direction by the uncut outer wall 26. A plurality of cam claws 11 are formed. The outer peripheral wall 26 forming the cam pawl 11 is connected at both ends by the inner peripheral edge of the flange portion 23 and the groove bottom 28 of the annular concave portion 13, and accommodates and supports the damper spring 14 on the inner side surface of the cam pawl 11. At the same time, the engaging surface 29 of the cam claw 11 facing in the circumferential direction engages with the ratchet mechanism 10 to transmit the rotation of the cam 8 to the rotating member 9 via the ratchet mechanism 10.
[0015]
Further, as shown in FIGS. 4 and 5, each of the cam claws 11 of the cam 8 has an engaging surface 29 which is perpendicular to a circumferential direction in which the ratchet mechanism 10 can be engaged. Are formed at both ends. As shown in FIG. 4, a locking groove 16 for receiving a locking end 15 of the damper spring 14 formed in the annular concave portion 12 for storing the damper spring 14 of the rope reel 4 is also symmetrical in the circumferential direction. By changing the winding direction to a different damper spring, it is possible to cope with an engine having a reverse rotation direction.
[0016]
The rope reel 4 is assembled to the support shaft 5 formed in the case 1, one end of the damper spring 14 is locked in the locking groove 16 of the rope reel 4, and mounted on the boss 19 of the rope reel 4. The cam 8 is overlapped on the side surface of the rope reel 4 so that the locking end 17 at the other end 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 the base 22. The center of the cam 8 is rotatably supported by the base of the screw 22 with respect to the support shaft 5, 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. Prior to the start operation of the engine, the ratchet mechanism 10 formed on the rotating member 9 connected to the crankshaft of the engine is in a state of being moved inward by the action of the spring, and is in contact with 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 pawl 11 of the cam 8 comes into contact with 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 of the cam 8 increases and the rotational load of the cam 8 increases. However, since the damper spring 14 is twisted to absorb the load, 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 stored 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 the outer periphery of the bosses 19 and 20 formed on the rope reel 4 and the cam 8 is tightly wound on the rope reel 4 and the damper spring 14. No longer acts. The winding portion of the damper spring 14 is uniformly wound around the boss portions 19 and 20, so that 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 rotation of the rope reel 4 is stopped. It is transmitted directly to the cam 8.
[0019]
At this time, an unbalanced load acts on the cam 8 between the ratchet mechanism 10 engaged with the cam pawl 11 and the locking hole 18 supporting the damper spring 14. Since the outer peripheral edge 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 inclination deformation of the cam 8 due to the unbalanced load is suppressed.
[0020]
When the rope reel 4 is further rotated and the rotational force exceeds the starting resistance of the engine, the rotational force of the rope reel 4 due to the pulling of the recoil rope 2 and the rotational force stored in the damper spring 14 are released to the cam 8 side. As a result, the power is transmitted to the rotating member 9 via the ratchet mechanism 10, so that the crankshaft of the engine is rotated at a stretch and the engine is started. When the engine starts and the crankshaft rotates, the ratchet mechanism 10 rotates outward due to the action of the centrifugal force and separates from the cam pawl 11 of the cam 8, and the rotation of the engine is not transmitted to the cam 11. 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 stored in the recoil spring 6, and the recoil rope 2 is rewound on the rope reel 4.
[0021]
【The invention's effect】
As described above, according to the present invention, the opening is formed by partially cutting out the outer peripheral wall of the annular recess accommodating the damper spring formed on the cam, and the cam pawl is formed by the remaining outer peripheral wall that is not cut off. Therefore, there is no need to form a cam claw projecting outside the outer peripheral wall forming the annular concave portion, and the outer peripheral wall of the annular concave portion can be formed outside by that much, and the cam 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 a large winding diameter can be accommodated in this annular recess. The storage capacity can be increased, and a recoil starter that can be easily operated can be provided.
[0022]
In addition, when the same damper spring as that of the related art is used, the outer shape of the cam can be reduced, and a rotating member such as a flywheel magnet or a drive pulley disposed on the outer periphery of the cam and a case for housing these members. Can be designed to be smaller, and a compact and lightweight recoil starter can be provided.
[0023]
Further, according to the invention of claim 2, a flange portion projecting outward in the radial direction is integrally formed on an edge of the outer peripheral wall forming the annular concave portion of the cam, and both ends of the cam claw are formed with the bottom of the annular concave portion. Since both ends of the cam claw are supported by being connected 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]
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 in FIG. 1 with a rotating member removed; FIG. 3 is a longitudinal sectional side view of the same recoil starter as in FIG. 4 is a perspective view of a rope reel, a damper spring and a cam of the embodiment of FIG. 1; FIG. 5 is a plan view of a cam employed in the embodiment; FIG. 6 is the same as FIG. FIG. 7 is a longitudinal side view of a conventional recoil starter. FIG. 8 is a perspective view of a cam employed in a conventional recoil starter, and FIG. Side view [Description of symbols]
DESCRIPTION OF SYMBOLS 1 Case 4 Rope reel 8 Cam 9 Rotating member 10 Ratchet mechanism 11 Cam claw 12 Annular recess 13 Annular recess 14 Damper spring 23 Flange 25 Annular recess 26 Outer peripheral wall 27 Opening 28 Bottom 29 Engaging surface

Claims (2)

A drive unit including a rope reel wound with a recoil rope, a cam having a cam claw disposed adjacent to the rope reel and engaging with a ratchet mechanism, and a damper spring interposed between the rope reel and the cam. A recoil device for starting an engine by transmitting a rotational force on a roaring part side rotationally driven by the recoil rope to a rotating member via a ratchet mechanism provided on a rotating member attached to a crankshaft of the engine. In the starter, an annular concave portion for accommodating a damper spring is formed facing the joining surface between the rope reel and the cam, and both ends of the damper spring accommodated in the annular concave portion are respectively engaged with the rope reel and the cam. The rope reel and the cam are connected via a damper spring, and further, an annular concave portion of the cam is formed. 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 outward in the radial direction is integrally formed on one side of an outer peripheral wall forming an annular concave portion of the cam. The recoil starter according to claim 1, wherein the recoil starter is connected and supported.

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