JP3914846B2 - Recoil starter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention rotates a rope reel by pulling a recoil rope wound around the rope reel, and transmits the rotation of the rope reel to a rotating member connected to the engine side via a one-way clutch mechanism such as a ratchet mechanism. The present invention also relates to a recoil starter that starts the engine by the rotation of the rotating member.
[0002]
[Prior art]
The rotation of the rope reel that is rotated by pulling the recoil rope is transmitted to the cam, and further, the flywheel magnet on the engine side or the drive pulley via a one-way clutch mechanism such as a centrifugal ratchet mechanism that is engaged with and disengaged from the cam. In the recoil starter configured to rotate the rotating member, a 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 rope reel rotates with 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 so as to be transmitted to a cam.
[0003]
As shown in FIG. 6, the conventional recoil starter includes a damper spring 34 accommodated in annular recesses 32 and 33 formed on opposing surfaces of the rope reel 30 and the cam 31, and the damper spring 34 is bent into a U shape. One end 35 is accommodated in an engaging groove 36 formed in the rope reel 30, and the other end 37 bent in the axial direction is inserted into an opening 38 formed in the cam 31. The rope reel 30 is rotated by pulling the rope 39 wound around the rope reel 30, and the cam 31 is rotated via the damper spring 34. When the cam 31 is prevented from rotating 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 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 cam 31 is rotated to start the engine.
[0004]
[Problems to be solved by the invention]
In the above prior art, both ends of the damper spring 34 are fixedly engaged with the rope reel 30 and the cam 31, and these ends cannot move in the radial direction. When the rotational force of the rope reel 30 is deformed by the damper spring 34, the central portion of the winding portion of the damper spring 34 is wound around the outer peripheral surfaces of the boss portions 40 and 41 of the rope reel 30 and the cam 31. It will be in the state where both ends will be changed to the state where it floated from the peripheral face of boss parts 40 and 41. In such a state, excessive stress may be generated at the bent portions at both ends of the damper spring 34, and the damper spring 34 may be damaged.
[0005]
Further, in order to prevent the load on the damper spring 34 from exceeding the set value, a stopper means is formed between the rope reel 30 and the cam 31 so that the relative rotation angle between the rope reel 30 and the cam 31 is regulated. However, in this case, there is a drawback that when the stopper is operated, there is a feeling of collision and the impact is transmitted to the hand pulling the recoil rope 39, and the feeling during starting operation is not good. Furthermore, since the conventional cam 31 is only supported at the center by a support shaft 43 formed on the case 42 so as to be rotatable, only one ratchet 45 is engaged with the claw 44 of the cam. Thus, when the spring force by the damper spring 34 is applied, an eccentric load is applied to the cam 31 and a strong tilting force is applied, which may damage the cam 31.
[0006]
The present invention solves the above-mentioned problems of the prior art, suppresses excessive displacement of the damper spring, improves the durability of the damper spring, and suppresses the eccentric load of the cam, thereby improving the durability of the cam. It is an object to improve the durability of the recoil starter by improving it.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a recoil starter according to the present invention includes a rope reel that is rotatably mounted on a support shaft formed inside a case and winds the recoil rope, and the rope in the direction of winding the recoil rope. A rotary member attached to a crankshaft of an engine provided with a mainspring for rotating and energizing a reel, a cam provided so as to be rotatable with respect to the support shaft, and a one-way clutch mechanism which engages with and disengages from the cam; And a boss part formed in the outer surface of the rope reel and the cam so as to face each other, and a coil spring-like shape arranged on the outer periphery of the both boss parts and locked at both ends by the rope reel and the cam, respectively. In a recoil starter that is composed of a damper spring and transmits the rotational force of the rope reel to the cam via the elasticity of the damper spring Wherein it is butted end surfaces of the boss portions formed on the rope reel and cam abut each other at a substantially intermediate position of the winding portion of the damper spring, the rope reel and the cam support portions at both ends of the damper spring When the damper spring is elastically deformed by the starting resistance of the engine, the entire circumference of both bosses formed on the rope reel and cam are supported by a movably supported radial portion with respect to the locking portion of the damper spring. It is characterized by being uniformly wound around the surface.
[0009]
According to a second aspect of the present invention, the cam has an outer periphery in which a center support portion formed by an end surface of a support shaft and an outer peripheral side surface of a flange portion formed on the cam so as to protrude radially outward are engaged with a side surface of a rope reel. It is characterized by being supported so as to be rotatable at two places with the support part.
[0010]
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 the end of a recoil rope 2 exposed to the outside of the case 1, so that the rope reel is accommodated in the case 1. 4 is rotated, and the rotating member 9 connected to the crankshaft of the engine is rotated via a ratchet mechanism 10 that engages with a cam claw 11 formed on the outer peripheral surface of the cam 8 rotated by the rope reel 4. Is configured to start the engine.
[0011]
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.
[0012]
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 by the rotational force accumulated in the recoil spring 6 by releasing the recoil rope 2. Operates to rewind.
[0013]
A cam 8 for transmitting the rotation of the rope reel 4 to the crankshaft side of the engine is rotatably attached to an end surface of the reel support shaft 5 formed in the case 1 by a screw 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.
[0014]
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.
[0015]
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.
[0016]
The locking end 15 of the damper spring 14 locked by the rope reel 4 is accommodated in the locking groove 16 so as to be movable in the outer peripheral surface direction of the boss portion 19 of the annular recess 12 with the rope reel 4. The locking hole 18 formed in the bottom of the annular recess 13 of the cam 8 is formed as a long hole in the radial direction, and the other end side of the damper spring 14 is in the locking hole 18. The locking end portion 17 is loosely fitted so that the outer peripheral surface of the boss portion 20 of the cam 8 can be approached. Thus, when the winding portion of the damper spring 14 is wound around the boss portions 19 and 20, the entire length of the winding portion of the damper spring is evenly wound around the boss portions 19 and 20 as shown in FIG. This state is the same as that of a known spring clutch mechanism. When the winding portion of the damper spring is wound around the boss portions 19 and 20 of the rope reel 4 and the cam 8, the boss portions 19 and 20 act as a spring clutch. Are connected in the direction of rotation.
[0017]
As shown in FIGS. 3 and 4, a flange portion 23 projecting radially outward is integrally formed on one side of the cam 8, and an annular guide 24 formed on the outer peripheral side surface of the flange portion 23. Is accommodated in an annular recess 25 formed on the side surface of the rope reel 4 to guide relative rotation between the cam 8 and the rope reel 4. 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 is rotatably supported by the annular recess 25 of the rope reel 4 on the outer peripheral side of the flange 23. The inclination of the cam 8 due to the unbalanced load acting on the cam 8 is suppressed, and the breakage due to the unbalanced load is prevented.
[0018]
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.
[0019]
At this time, when the damper spring 14 is twisted, the rotational force on the rope reel 4 side is stored in the damper spring 14. The damper spring 14 is twisted to reduce the outer diameter of the winding portion and is wound on the outer peripheral surfaces of the boss portions 19 and 20 of the rope reel 4 and the cam 8 so that no further stress acts on the damper spring 14. 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 directly transmitted to the cam 8. At this time, since the locking end portions 15 and 17 at both ends of the damper spring 14 move inward, almost the entire length of the winding portion of the damper spring 14 is brought into close contact with the outer peripheral surfaces of the boss portions 19 and 20. No excessive stress is generated at the base.
[0020]
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.
[0021]
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 does not come into contact with the cam claw 11 of the cam 8. 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.
[0022]
【The invention's effect】
As described above, according to the first aspect of the present invention, when an excessive load is generated on the engine side, the damper spring is wound around the outer peripheral surface of the boss formed on the lobe reel and the cam so that the damper spring is overloaded. Therefore, it is possible to prevent a decrease in durability due to an excessive load of the damper spring. In addition, according to the present invention, the winding portion of the damper spring is gradually wound around the boss portion, and the rope reel and the cam are integrally rotated and connected, so that there is no collision feeling like a conventional stopper and the recoil rope is pulled. The feeling when starting the engine is improved.
[0023]
Further, since the engaging portions at both ends of the damper spring are supported so as to be movable in the direction of the outer peripheral surface of the boss portion, almost the entire length of the winding portion of the damper spring is wound around the boss, and the lobe reel and the cam are acted on by the spring clutch. Therefore, the stress generated at the engaging portions at both ends of the damper spring can be kept low, and the durability of the damper spring can be extended.
[0024]
Moreover, Russia since Puriru and the end face of the boss portion formed in the cam is butted at approximately intermediate position of the winding portion of the damper spring, more than a certain number of times on the outer circumferential surface of the boss windings both of the damper spring even Since the rope reel and the cam are rotationally coupled by the action of the spring clutch, the rotational force can be transmitted from the rope reel to the cam without generating excessive stress on the damper spring.
[0025]
According to the second aspect of the present invention , since the cam is rotatably supported by the screw and the flange portion at the two locations of the center portion and the outer peripheral portion, it is difficult for the cam to be displaced due to an uneven load, and the two ratchets Even if one of the mechanisms does not engage with the cam pawl, or even a mechanism having only one ratchet mechanism, the tilt caused by a strong bias load is prevented and the cam is not damaged.
[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 a recoil starter that is the same as FIG. 4 is a perspective view of the rope reel, damper spring, and cam of the embodiment of FIG. 1. FIG. 5 is a longitudinal side view of the same recoil starter as in FIG. 3 in a state where the damper spring is tightened. FIG. Vertical side view [Fig. 7] Vertical side view of the same conventional recoil starter as in Fig. 6 showing a state where excessive stress is generated in the damper spring [Explanation of symbols]
1 Case 4 Rope reel 5 Support shaft 8 Cam 9 Rotating member 10 Ratchet mechanism 11 Cam claw 12 Annular recess 13 Annular recess 14 Damper spring 15 Engagement end 16 Engagement groove 17 Engagement end 18 Engagement hole 19 Boss 20 Boss part 22 Screw 23 Flange part 24 Annular guide 25 Annular recess

Claims (2)

A rope reel that is rotatably mounted on a support shaft formed inside the case and winds a recoil rope, a spring that urges the rope reel to rotate in a direction to wind the recoil rope, and the support shaft A rotating member attached to the crankshaft of an engine provided with a one-way clutch mechanism that engages and disengages with the cam, and the rope reel and the cam are arranged in abutment with each other. Bosses formed with the same outer diameter, and coil spring-like damper springs arranged on the outer periphery of both bosses and locked at both ends to a rope reel and a cam, respectively. in the recoil starter which is adapted to transmit to the cam via the elastic force of the damper spring, formed on the rope reel and cam abut with each other Substantially are butted at an intermediate position, the movable support portion at both ends of the damper spring in a radial direction relative to the locking portion of the rope reel and the cam of the winding portion of the end face said damper spring both boss portions which When the damper spring is elastically deformed by the engine starting resistance, the entire length of the winding portion of the damper spring is uniformly wound around the outer peripheral surfaces of both boss portions formed on the rope reel and cam. Features a recoil starter. The cam rotates at two locations: a center support portion by the end surface of the support shaft, and an outer periphery support portion in which the outer peripheral side surface of the flange portion formed on the cam and projecting radially outward is engaged with the side surface of the rope reel. The recoil starter according to claim 1, wherein the recoil starter is supported.

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