JP2509574Y2 - General-purpose engine starter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a starter device for a general-purpose engine including a recoil starter and an electric starter.

(Prior art) In a general-purpose engine, in order to facilitate starting of the engine, in addition to the recoil starter that operates by pulling the recoil rope, an electric starter that operates by a starter motor is provided, and it is normally started by the electric starter. In an emergency, a starter device that is started by a recoil starter has been used.

In the recoil starter of such a starter device, the rotation of the reel due to the pulling operation of the recoil rope is transmitted to the pulley fastened to the crankshaft via the first clutch mechanism. At this time, the claw of the first clutch mechanism is adapted to mesh with the engaging portion of the reel. Further, in the electric starter, the rotation from the starter motor is transmitted to a cylindrical driven gear that rotates concentrically with the crankshaft via some gears, and is transmitted to the pulley via the second clutch mechanism. At this time, the claw of the second clutch mechanism is adapted to mesh with the engaging portion of the driven gear.

The driven gear is generally rotatably supported by a bearing mechanism provided between the inner peripheral surface of the driven gear and the outer peripheral surface of the pulley. As a prior art, there is Jitsukaihei 1-83176.

(Problems to be solved by the invention) By the way, in the above structure, since the bearing mechanism of the driven gear is mounted on the outer peripheral surface of the pulley, the pulley always rotates while the engine is running, and therefore the rotational load is increased. Becomes large (for example, 6000 to 10000 rpm). For this reason, it is necessary to use a ball bearing or the like for high rotation as the bearing mechanism of the driven gear, and the size of the bearing portion in the radial direction becomes large and the entire starter device becomes large, resulting in a heavy weight, resulting in a cost reduction. It was high. Further, since the ball bearing has a large rotational load, the temperature becomes considerably high, and a high-grade grease having good heat resistance is required as a lubricant, which also leads to a high cost.

Further, in the above conventional structure, since the bearing case of the driven gear and the bearing case of the intermediate gear that meshes with the driven gear are not the same, the cumulative tolerance of the center distance between the driven gear and the intermediate gear is large, and the meshing of the driven gear is It was easy to get unstable. That is, the center position of the bearing portion of the driven gear is the crankshaft, the crankshaft bearing, the crankcase,
Due to the influence of the starter mounting part, etc., the cumulative tolerance of each part became considerably large, and the runout of the crankshaft was added, and the meshing of the driven gear was likely to become quite unstable.

The present invention has been made in order to solve the above inconvenience, and provides a starter device for a general-purpose engine that is small and inexpensive, and that can extremely stabilize the meshing of the driven gear during operation of the electric starter. The purpose is to do.

(Means for Solving Problems) In order to achieve the above object, the present invention provides a reel that rotates concentrically with a crankshaft by a pulling operation of a recoil rope.
A recoil starter having a first clutch mechanism that transmits the rotation of the reel to a pulley that is fastened to the crankshaft, a cylindrical driven gear that receives rotation from the starter motor, and rotates concentrically with the crankshaft, and a driven gear. In a starter device for a general-purpose engine including a second clutch mechanism that transmits the rotation of a driven gear to a pulley, a bearing portion that rotatably supports a driven gear is provided on the outer surface side of the driven gear, and the above-mentioned bearing A bearing case of a driven gear having a portion formed integrally with the bearing case of an intermediate gear that meshes with the driven gear, and a groove extending in the circumferential direction is formed on the outer peripheral surface of the driven gear facing the bearing portion. Is.

(Operation) In the electric starter, when the engine is started, the second clutch mechanism is disengaged and the starter motor is also stopped. Therefore, the rotation of the driven gear stops, and the bearing part receives a small rotational load (for example, 500
~ 1000 rpm) will be added. Therefore, any bearing can be used as long as it can withstand such a small rotational load, and a plain bearing or the like can be used as the bearing mechanism. Therefore, the bearing portion becomes smaller, and the operation of the bearing portion becomes stable even with general inexpensive grease having high versatility, since heat resistant high-grade grease is not required.

Further, since the bearing case having the bearing portion of the driven gear is provided integrally with the bearing case having the bearing portion of the intermediate gear that meshes with the driven gear, the tolerance of the center distance between both gears becomes extremely small, and The effect of crankshaft runout is also eliminated. Therefore, the meshing of the driven gear is extremely stable.

Moreover, since a groove extending in the circumferential direction is formed on the outer peripheral surface of the driven gear facing the bearing portion, lubricating grease is stored in the groove, and the grease enters the bearing portion by centrifugal force during operation, Lubrication between the outer peripheral surface and the bearing becomes smooth.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. First
1 is a vertical cross-sectional view showing a starter device for a general-purpose engine according to the present invention, FIG. 2 is a view taken along arrow II in FIG. 1, and FIG. 3 is III in FIG.
FIG. 4 is a sectional view taken along the line IV-IV in FIG. In FIG. 1, a pulley 2 is fastened to a crankshaft 1 by a nut 3. A reel 5 is rotated by pulling the recoil rope 4. Reel 5 is crankshaft 1
It is designed to rotate concentrically with the recoil case 7
It is rotatably mounted on a support shaft 6 protruding from the crank shaft 1 toward the crank shaft 1. 4a (Fig. 2) is recoil rope 4
Is a handle for pulling.

Reference numeral 31 is a first clutch mechanism that transmits the rotation of the reel 5 to the pulley 2. This clutch mechanism 31 is a pulley 2
And a spring 31c that rotatably supports the claw 31a while engaging the claw 31a with the engaging portion 31b.
As shown in the figure, when the pulley 2 rotates in the direction of arrow C, the claw 31a hits the engaging portion 31b to idle, and when the rotation of the engine increases, the claw 31a vibrates outward as indicated by arrow A due to the centrifugal force. Therefore, the structure is such that it does not come into contact with the engaging portion 31b.

A recoil starter is configured by the recoil rope 4, the reel 5, the first clutch mechanism 31, and the like as described above.

Reference numeral 8 is a starter motor, and 9 is a motor shaft. Motor 8
Is to rotate the drive gear 10 fixed to the motor shaft 9 by being operated by a start switch (not shown). The rotation of the drive gear 10 is, as shown in FIG. 4, a first intermediate gear 11, a first support pin 15, a second intermediate gear 12, and a third intermediate gear 12.
The intermediate gear 13 and the second support pin 16 are transmitted to the fourth intermediate gear 14 while being decelerated.

Reference numeral 20 denotes a cylindrical driven gear, which is meshed with the fourth intermediate gear 14 by teeth 20b formed in a substantially rear half of the outer peripheral surface 20a. Reference numeral 21 denotes a bearing case that is fitted around the front half of the driven gear 20 and rotatably supports the driven gear 20. 21a is driven gear 2
The bearing portion faces the outer peripheral surface 20a of 0, and the outer peripheral surface 20a is slidable with respect to the bearing portion 21a. A groove 20c that extends in the circumferential direction is formed on the outer peripheral surface 20a facing the bearing portion 21a, and the grease enters the bearing portion 21a by centrifugal force during operation by collecting lubricating grease in the groove 20c, Outer peripheral surface 2
Lubrication between 0a and the bearing portion 21a is made smooth. As shown in FIG. 7, the groove 20c may have a plurality of grooves extending in the axial direction, or may be a combination of both. The bearing case 21 is sandwiched between the crankcase 22 and the recoil case 7. The bearing case 21 is provided with a bearing portion 16a on one side of the shaft 16 of the intermediate gears 13 and 14. That is, the bearing portion 21a of the driven gear 20 and the intermediate gear 1
Since the bearing portions 16a of 3 and 14 are provided in the same member, the tolerance of the center distance between the driven gear 20 and the intermediate gears 13 and 14 is extremely small, and the engagement of the driven gear 20 is extremely small. It has a stable structure. The motor 8 is supported by the bearing case 21, and 8a is a motor case.

A wheel 23 is rotatably fitted on the pulley 2. Reference numeral 24 denotes a damper provided between the flange 23a of the wheel 23 and the pulley 2 so as to be fixed to them.

A second clutch mechanism 32 transmits the rotation of the driven gear 20 to the wheel 23. This clutch mechanism 32 is a wheel
A claw 32a fixed to 23, an engaging portion 32b formed continuously in substantially the front half of the inner peripheral surface of the driven gear 20, and a claw 32a engaging the engaging portion 32a.
The engaging portion 32b is a spring 32c that is rotatably supported in a state of being meshed with b, and the engaging portion 32b is radially outside the engaging portion 31b of the first clutch mechanism 31 about the crankshaft 1, that is, the outside. It is provided near the diameter. As shown in FIG. 6, the second clutch mechanism 32 has a wheel 23 with an arrow C.
32a when rotating in the direction (engine rotation direction)
Has a structure in which the engaging portion 32b is struck to idle, and when the rotation of the engine rises, the centrifugal force swings the engaging portion 32b as shown by arrow A so as not to contact the engaging portion 32b.

In the structure described above, the outer peripheral surface 20a is made of the same material as the driven gear 20, but another material component having better bearing property may be integrally provided on the outer peripheral surface 20a by press fitting or the like.
Further, the bearing portion 21a is also made of the same material as the bearing case 21, but other material parts may be integrally provided by press fitting or the like as described above.

Motor 8, gears 10 to 14, driven gear 2 as described above
The 0, the second clutch mechanism 32, the wheel 23, the damper 24, etc. constitute an electric starter. Third
The figure shows the shape of the damper 24.

Next, the operation will be described. The start-up by the electric starter normally used is as follows. When the motor 8 rotates, the drive gear 10 and the first to fourth intermediate gears 11 to 14 rotate, and the driven gear 20 rotates. This rotation is transmitted from the engaging portion 32b of the second clutch mechanism 32 to the claw 32a, and further to the pulley 2 via the wheel 23 and the damper 24. Then, the crankshaft 1 rotates and the engine is started. When the engine is started, the claw 32a is disengaged from the engaging portion 32b by the centrifugal force. Even if the pulley 2 rotates in the engine rotation direction, the first clutch mechanism 31 idles, so the reel 5 does not rotate.

On the other hand, the start-up by the recoil starter used in an emergency where power cannot be supplied is as follows. The reel 5 is rotated by the pulling operation of the recoil rope 4. This rotation is transmitted from the engaging portion 31b of the first clutch mechanism 31 to the pulley 2 via the claw 31a. Then the engine is started. When the engine is started, the claw 31a is disengaged from the engaging portion 31b by the centrifugal force. Even if the pulley 2 rotates in the engine rotation direction, the second clutch mechanism 31 idles, so that the driven gear 20, the intermediate gears 11 to 14, etc. do not rotate.

In the above structure, when the engine is started during starting by the electric starter, the second clutch mechanism 32
The engagement between the claw 32a and the engaging portion 32b is released. On the other hand, the motor 8
Is stopped. Therefore, the rotation of the driven gear 20 stops with the end of the engine starting operation. For this reason the bearing case
The bearing portion 21a of 21 receives only a small rotational load (for example, 500 to 1000 rpm) when the engine is started. Therefore, a plain bearing or the like can be adopted as the bearing mechanism. Therefore, the bearing portion 21a becomes small, and the operation of the bearing portion 21a becomes stable even with a general inexpensive grease that has high versatility and does not require high-quality grease with good heat resistance.
The meshing of the driven gear 20 becomes stable.

Further, since the rotational force of the motor 8 cannot be adjusted by starting the electric starter, the second clutch mechanism 32
Impact force at the time of engagement between the claw 32a of the robot and the engaging portion 32b, and the motor 8
It is necessary to reduce the load applied to. In the present invention, the nail
A damper 24 is fixed to the wheel 23 fixed to 32a, and the damper 24 is fixed to the pulley 2. Therefore, the wheel 23 slightly rotates with respect to the pulley 2 due to the elastic deformation of the damper 24 in the circumferential direction. Therefore, the claw 32a and the engaging portion 3
The impact force at the time of meshing with 2b is alleviated, and the load applied to the motor 8 is also reduced.

Further, generally, the first and second clutch mechanisms 31 and 32 that transmit the driving force at the time of starting are subjected to an impact force proportional to the engine torque at the time of starting, but in the above structure, the engagement of the second clutch mechanism 32 is engaged. The portion 32b is the engaging portion 31b of the first clutch mechanism 31.
The impact force that the engaging portion 32b receives from the claw 32a is compared to the impact force that the engaging portion 32a receives from the engaging portion 31b because it is provided on the outer side in the radial direction around the crankshaft 1, that is, closer to the outer diameter. And it becomes small in itself. On the other hand, since the first clutch mechanism 31 whose impact force is adjusted by the elasticity of the recoil rope 4 is provided closer to the inner diameter than the second clutch mechanism 32, the first clutch mechanism 31 can be made smaller and the device can be downsized.

As described above, according to the present invention, since the bearing portion 21a that rotatably supports the driven gear 20 is provided on the outer surface side of the driven gear 20, the bearing portion 21a has a small rotational load at the time of starting. Therefore, it is not necessary to use an expensive bearing such as a ball bearing as a bearing mechanism, and an inexpensive mechanism such as a plain bearing can be adopted, which is lower in cost than conventional devices. A lightweight and compact device can be obtained.

Further, since the bearing portion 21a of the driven gear 20 is integrally formed with the bearing portion 16a of the intermediate gears 13 and 14 by the same member, the tolerance of the center distance between the driven gear 20 and the intermediate gears 13 and 14 should be minimized. Therefore, the meshing of the driven gear 20 can be extremely stabilized.

Moreover, since the groove 20c extending in the circumferential direction is formed on the outer peripheral surface 20a of the driven gear 20 facing the bearing portion 21a, lubricating grease is stored in the groove 20c, and the grease is centrifugally applied to the bearing portion 21a during operation. The outer peripheral surface 20a and the bearing portion 21a can be smoothly lubricated by entering.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a starter device for a general-purpose engine of the present invention, FIG. 2 is a view taken in the direction of arrow II of FIG. 1, and FIG. 3 is a view of FIG.
III arrow view, FIG. 4 is a sectional view taken along line IV-IV of FIG. 2, FIG. 5 is a sectional view of the first clutch mechanism taken along line VV of FIG. 1, and FIG. 6 is VI of FIG. FIG. 7 is a cross-sectional view of the second clutch mechanism taken along the line -VI, and FIG. 7 is a perspective view showing another example of grooves formed on the outer peripheral surface of the driven gear. 1 ... Crank shaft, 2
…… Pulley, 4 …… Recoil rope, 5 …… Reel,
8 ... Starter motor, 20 ... Driven gear, 21 ... Bearing case, 31 ... First clutch mechanism, 31a ... Claw, 31b ...
Engagement part, 32 ... Second clutch mechanism, 32a ... Claw, 32b ...
... Engagement part

Continuation of the front page (56) References: 1-74369 (JP, U)

Claims (1)

(57) [Scope of utility model registration request] 1. A recoil starter having a reel that rotates concentrically with a crankshaft when a recoil rope is pulled, and a first clutch mechanism that transmits the rotation of the reel to a pulley fastened to the crankshaft, and a starter motor. In a starter device for a general-purpose engine, a starter device for a general-purpose engine, comprising: a cylindrical driven gear that receives rotation of the crankshaft and rotates concentrically with a crankshaft; A bearing portion for rotatably supporting the gear is provided on the outer surface side of the driven gear, and the bearing case of the driven gear including the bearing portion is integrally formed with the same member as the bearing case of the intermediate gear meshing with the driven gear. A starter device for a general-purpose engine, characterized in that a groove extending in a circumferential direction is formed on an outer peripheral surface of a driven gear facing the portion.