JPH0649905Y2 - Small engine with starter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of a small engine with a starter which is mainly used as a driving device for a working machine such as a mower or a chemical sprayer.

(Prior Art) As a starter for a small engine with a starter, a manual recoil starter that starts the engine by pulling a rope is generally adopted. However, since a manual starter requires a considerable amount of force to pull the rope, for example, even in the case of a backpack-type working machine configured to start the engine by pulling the rope while carrying the engine, Since it is difficult to start the engine while it is carried on its back, the engine part is often borne on the back after starting the engine.Especially when the engine is frequently started and stopped, remove the engine part from the back each time. It was very inconvenient because I had to re-carry.

Further, conventionally, as shown in FIG. 7 (actual exploitation 64-11371), there has been known a combined starter in which an electric starter 13 is provided together with a recoil starter 12 so that both starters 12 and 13 can be appropriately used. 3 is a crankcase and 23 is a starter motor. In the case of this side-by-side starter, both starters 12 and 13 are separately arranged at each end side in the axial direction of the crankshaft 1, and a gear mechanism for transmitting rotation to the crankshaft 1 is required for each starter. The structure was complicated, the entire engine was large, and the cost was considerably high.

(Object of the Invention) The object of the present invention is to simplify the structure by sharing the torque transmission path from the recoil starter and the electric starter to the crankshaft, and to make it possible to appropriately connect the electric starter in the vicinity of the existing recoil starter. To provide a small engine with a starter.

(Technical means for achieving the object) In order to achieve the above object, the device according to claim 1 of the present application,
A starting gear, which is fitted to the outer periphery of one end of the crankshaft so as to be axially movable through an electric start position and a recoil start position in the axial direction via a one-way clutch, and concentrically faces one end of the crankshaft. An arranged recoil starter, an electric starter having a gear arranged radially outward of the starting gear and meshing with the starting gear at the electric starting position, and a ratchet fitted to the reel of the recoil starter via a cam feed mechanism, Equipped with a spring that urges the starting gear to the electric starting position and a friction plate for initial detent that engages with the axial recess of the ratchet and starts to rotate at a certain rotational torque or more. The facing parts are provided with protrusions that mesh with each other and are axially separated from each other before the reel is rotated. The cam feed mechanism consists of a spiral groove shaped to feed the ratchet to the starting gear side in the axial direction by the forward rotation of the reel and a lead groove that meshes with it.When the reel rotates forward, both protrusions are formed by axial movement of the ratchet. When engaged, the starting gear is positioned at the recoil starting position.

In order to simplify the lubrication in addition to the object of claim 1, the invention according to claim 2 or 3 is slightly different from the invention according to claim 1 in the arrangement of the one-way clutch and the mounting structure of the starting gear. .

That is, a starting shaft is axially movably fitted to an inner peripheral surface or an outer peripheral surface of a crankshaft portion in a crankcase via a one-way clutch, and a starting gear is fixed to an outer end portion of the crankcase of the starting shaft to start the engine. The gear and the starting shaft move together in the axial direction.

(Operation) When starting with the electric starter, the starter gear is rotated via the transmission gear by rotating the starter motor, whereby the crankshaft is rotated via the one-way clutch.

When starting with the recoil starter, pull the rope and rotate the reel. In the initial stage, the ratchet moves axially due to the cam action of the spiral teeth and the lead groove and the rotation stop action of the friction plate, the ratchet protrusion and the start gear protrusion engage with each other, and then the ratchet and the start gear integrally rotate. Direction, the starting gear disengages from the electric starter gear. When the rope is further pulled, the ratchet rotates together with the reel due to a rotational force larger than the frictional force of the friction plate, and the rotational force is transmitted to the crankshaft via the protrusion, the starting gear and the one-way clutch.

(Embodiment 1) FIG. 1 is a vertical sectional view of a small engine with a starter to which the invention according to claim 1 of the present application is applied, in which a crankshaft 1 is supported by a crankcase 3 via bearings 2 on both sides and both ends thereof. The parts respectively extend outside the crankcase 3.
6 is a piston, 7 is a cylinder, and 9 is a seal. Assuming that the output shaft 4 side is the front of the engine, a magnet rotor 8 is fixed to the front end portion of the crankshaft 1 and a clutch 11 is provided, and the clutch 11 is interlockingly connected to the output shaft 4 via the clutch 11. A recoil starter 12 is arranged on the axial extension of the rear end of the crankshaft 1, and an electric starter 13 is arranged near the recoil starter 12 on the radial side of the rear end of the crankshaft 1. A starting gear 16 common to both starters is arranged at the rear end portion.

The electric starter 13 has a starter motor 23, a pinion gear 27, and a reduction compound gear (transmission gear) 28. The reduction compound gear 28 meshes with the pinion gear 27 and also has a small diameter gear 28.
It has a.

The starting gear 16 is fitted on the outer periphery of the rear end of the crankshaft 1 via a one-way clutch 17, and the one-way clutch 17 also has a bearing 17a for supporting the starting gear, and the starting gear 16 can be moved in the axial direction. Support. A coil spring 21 is contracted between the starting gear 16 and the front stopper / spring receiving ring 18, and the starting gear 16 is biased rearward by the spring 21 and abuts on the rear locking ring 22. By doing so, the starting gear 16 is maintained in a position where it always meshes with the small diameter gear 28a on the electric starter side. Starting gear 1
An engaging projection 55 is formed on the rear surface of the ratchet 6 so as to be able to mesh with the projection 54 of the ratchet.

The recoil case 33 of the recoil starter 12 is fixed to the rear end wall of the crankcase 3 via the gear case 25 and integrally has a shaft portion 33a on the extension of the crankshaft core line, and the reel portion is provided on the outer peripheral surface of the shaft portion 33a. The inner tubular portion 35a of 35 is rotatably supported. The reel 35 is biased by the recoil spring 34 in the direction opposite to the direction of rotation of the crankshaft, and the rope 38 is wound around the outer peripheral annular groove 35b, and the rope 38 extends outside the recoil case 33 and has a tip portion. To recoil knob 39
Is stuck. A plurality of spiral teeth 43 are formed on the outer peripheral surface of the inner cylindrical portion 35a of the reel 35, and a cylindrical ratchet 40 is arranged, and a lead groove that meshes with the spiral teeth 43 is formed on the inner peripheral surface of the ratchet 40. 44 are formed. Further, on the inner peripheral surface of the ratchet, a plurality of recesses 45 for initial detent that extend in the axial direction are formed separately from the above-mentioned REET groove 44,
A friction plate 48 is engaged with the recess 45.
The friction plate 48 and the recoil case shaft 33 are
It is biased forward by a corrugated spring 49 that is contracted between the stepped portions of a and is pressed against the washer 50 on the front side. That is, washer
The friction plate 48 is adapted to rotate when the rotational torque exceeds the frictional force with the frictional force 50.

On the front end surface of the ratchet 40, as described above, the protrusion 54 that can be engaged with the protrusion 55 of the starting gear 16 is formed, and normally both the protrusions 54 and 55 are opposed to each other with an axial gap therebetween. .

FIG. 2 is a partial sectional view taken along the line II-II of the ratchet and reel portions in FIG. 1, in which four spiral teeth 43 and four lead grooves 44 are formed, for example.

FIG. 3 is a view of the ratchet and friction plate portions as viewed from the direction of arrow III in FIG. 1. The friction plate 48 has, for example, two protrusions, and recesses are formed in accordance with these protrusions.
Two 45 are also formed.

Next, the operation will be described. When starting with the electric starter 13, the starter motor 23 is rotated in the state shown in FIG. The rotational force is transmitted from the pinion gear 27 to the reduction compound gear 28, is decelerated there and is transmitted from the small diameter gear 28a to the starting gear 16, and rotates the clan shaft 1 via the one-way clutch 17.

When starting with the recoil starter 12, the reel 35 is rotated in the crankshaft rotation direction by pulling the recoil knob 39.

At the initial stage, the friction plate 48 does not rotate due to the frictional force between the friction plate 48 and the washer 50, so that the ratchet 40 is also prevented from rotating by the engagement between the friction plate 48 and the recess 45. Ratchet
The 40 does not rotate but moves forward in the axial direction by the cam action of the spiral teeth 43 and the lead groove 44. In the middle of this axial movement, the projections 54 and 55 mesh with each other, and then the starting gear 16 is pushed by the ratchet 40 and moves forward together, and as shown in FIG. Gear 28
It disengages from the small-diameter gear 28a, comes into contact with the front spring bearing plate 18, and stops its axial movement.

Further pulling the recoil knob 39 prevents the ratchet 40 from moving in the axial direction, so the reflection plate 48
The ratchet 40 starts to rotate in the crankshaft positive rotation direction against the frictional force of the crankshaft 1 and rotates the crankshaft 1 via the projections 54 and 55, the starting gear 16 and the one-way clutch 17.

When the rope 38 is returned after the engine is started, the ratchet 40 is in the first position.
Returning to the original rear position in the drawing, the starting gear 16 is also returned to the original rear position in FIG. 1 by the coil spring 21, and the starting gear 16 and the small diameter gear 28a of the reduction compound gear 28 are brought into mesh with each other.

(Embodiment 2) FIG. 5 is a longitudinal sectional view of a small engine with a starter to which the invention according to claim 2 is applied, and the same parts as those in Embodiment 1 are designated by the same reference numerals. In FIG. 5, the arrangement of the one-way clutch 17 and the mounting structure of the starting gear 16 are different from those of the first embodiment.

That is, in FIG. 5, the rear portion of the crankshaft 1 is formed in a cylindrical shape in the crankcase 3, and the inner peripheral surface of the cylindrical rear portion is formed.
A one-way clutch 17 is fitted in 1a, and a starting shaft 60 is supported on the inner circumference of the one-way clutch 17 so as to be axially movable. The starting shaft 60 projects rearward from the crankcase 3,
A seal 9 is arranged between the crankcase 3 and the crankcase 3.
A starting gear 16 is fixed to the rear end of the starting shaft 60, and a coil spring is provided between the starting gear 16 and the front spring bearing plate 18.
21 is compressed, the starter gear 16 and the starter shaft 60 are integrally biased rearward by the coil spring 21, and the starter gear 16 is a small-diameter gear of the reduction gear 28 by a locking ring (washer) 65 at the front end of the starter shaft. It is locked at a position where it always meshes with 28a.

The operation is substantially the same as that of the first embodiment, but the starting gear 16 moves axially integrally with the starting shaft 60, and the rotational force is the starting gear 16.
Is transmitted to the crankshaft 1 via the starting shaft 60 and the one-way clutch 17.

Further, in this structure, by disposing the one-way clutch 17 in the crankcase 3, lubrication with the mixed gasoline in the crankcase 3 is possible, and lubrication such as grease application is unnecessary.

Further, since the starting shaft 60 rotates only at the time of starting and stops during operation, the durability and sealing property of the oil seal are good.

(Embodiment 3) FIG. 6 is a vertical cross-sectional view of a small engine with a starter to which the invention described in claim 3 is applied, and the same parts as those in Embodiment 1 are designated by the same reference numerals. In FIG. 6, a starting shaft 60 is provided as in the second embodiment, and the starting shaft 60 is axially movably fitted to the crankshaft 1 via the one-way clutch 17 in the crankcase 3. 60 is arranged on the outer peripheral surface of the crankshaft 1.

That is, the starting shaft 60 projects into the crankcase 3 and has a cylinder portion 60a formed at the front end thereof. The one-way clutch 17 is fitted on the inner peripheral surface of the cylinder portion 60a, and the outer peripheral surface of the rear end portion of the crankshaft 1 is fitted. An inner peripheral surface of the one-way clutch 17 is fitted to the shaft so as to be movable in the axial direction. The outer peripheral surface of the tubular portion 60a is the crankcase 3
Is supported by the boss portion of the bearing via a bearing 62. The starting gear mounting structure at the rear end of the starting shaft 60 is similar to that of the second embodiment (FIG. 5). However, reduce the starting gear 16 to the small gear 28 of the compound gear 28.
The rear end surface of the starting shaft tubular portion 60a is brought into contact with the rear wall of the crankcase 3 as a means for locking the position at which it constantly meshes with a.

The operation is almost the same as that of the first embodiment, but the starting gear 16 is the starting shaft.
It moves axially with 60 and one-way clutch 17.

(Other Embodiments) (1) In each of the above embodiments, the spiral tooth 43 is formed on the lead 35 and the lead groove 44 is formed on the ratchet 40.
44 may have a structure in which the spiral teeth 43 are formed on the ratchet 40.

(Effects of the Invention) As described above, the inventions according to claims 1, 2, and 3 of the present application are as follows: (1) Rotation from an electric starter or rotation from a recoil starter is connected to a crankshaft via a one-way clutch. Since the rotation transmission mechanism for starting is shared by transmitting it to the crankshaft through one of the starting gears, the structure is simpler, lighter and less expensive than the conventional combined starter device. .

(2) Since the recoil starter and the nearby electric starter are connected to the recoil starter, the recoil starter can be placed in the dead space of the engine, and the placement space of both starters does not change much from the placement space of the recoil starter only. Can be avoided.

(3) The starting gear 16 is configured to be axially movable between the recoil starting position and the electric starting position, and
The recoil starter 12 is provided with a ratchet 40 driven by a cam feed mechanism, and at the time of electric starting, the ratchet 40 of the recoil starter 12 is disengaged from the starting gear 16.
The starting gear 16 meshes only with the gear 28a of the electric starter 13, while at the time of recoil start, the gear 28a of the electric starter 13 disengages from the starting gear 16 and the projection 55 of the starting gear 16 meshes only with the projection 54 of the ratchet 40. It is like this.

That is, at each start of the electric start and the recoil start, the starting gear 16 meshes only with the gears or protrusions required for starting and disengages from unnecessary gears. No extra load other than the above load is applied, and the effect of reducing the starting operation force is great.

Further, the inventions according to claims 2 and 3 of the present application have the following advantages.

(1) Since the one-way clutch is located in the crankcase, the mixed gasoline in the crankcase can be used for lubrication, and there is no need to supplement grease or the like.

(2) Since the starting shaft protruding to the outside of the crankcase rotates only at the time of starting and does not rotate during operation, the sealing property and durability of the oil seal between the starting shaft and the crankcase are good.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a small engine with a starter to which the invention according to claim 1 of the present application is applied, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 4 and 5 are longitudinal sectional views of the same portion as in FIG. 1 when starting the recoil starter,
5 is a vertical sectional view of a small engine with a starter to which the invention of claim 2 is applied, FIG. 6 is a vertical sectional view of a small engine with a starter to which the invention of claim 3 is applied, and FIG. 7 is a conventional example. FIG. 1 ... Crankshaft, 3 ... Crankcase, 12 ... Recoil starter, 13 ... Electric starter, 16 ... Starting gear, 17 ... One-way clutch, 21 ... Spring, 23 ... Starter motor, 33 ... Recoil Case, 35 ... Reel, 40 ... Ratchet, 43 ... Spiral tooth, 44 ... Lead groove, 45 ... Recess, 48 ... Friction plate, 49 ... Wave spring, 54, 55 ... Protrusion, 60 ... …
Starting axis

Claims (3)

[Scope of utility model registration request] 1. A starting gear fitted to the outer periphery of one end of a crankshaft so as to be axially movable between an electric starting position and a recoil starting position in the axial direction via a one-way clutch, and one end of the crankshaft. A recoil starter, which is concentrically opposed to this, an electric starter having a gear arranged radially outward of the starting gear and meshing with the starting gear at the electric starting position, and a reel of the recoil starter are fitted via a cam feed mechanism. It is equipped with a mating ratchet, a spring that biases the starting gear to the electric starting position, and a friction plate for initial rotation that engages with the axial recess of the ratchet and starts to rotate at a certain rotational torque or more. Gears and ratchets are in mesh with each other, and they are axially separated from each other before reel rotation. The cam feed mechanism has a spiral groove and a lead groove that meshes with the spiral groove that sends the ratchet to the starting gear side in the axial direction by the forward rotation of the reel, and the cam feed mechanism moves by the axial movement of the ratchet during the forward rotation of the reel. A small engine with a starter, characterized in that both projections are engaged and the starting gear is positioned at the recoil starting position. 2. A crankshaft, one end of which is formed in a tubular shape in a crankcase, and an axial electric start position and recoil start position extending through an inner periphery of the tubular portion of the crankshaft via a one-way clutch. A starter shaft that fits axially so that it can move axially, a starter gear fixed to the starter shaft, a recoil starter that is concentrically opposed to the starter shaft, and an electric starter position that is arranged radially outward of the starter gear. , An electric starter having a gear that meshes with the starting gear, a ratchet that is fitted to the reel of the recoil starter via a cam feed mechanism, a spring that urges the starting gear to the electric starting position, and an axial recess of the ratchet. The starting gear and the ratchet are opposed to each other with a friction plate for initial rotation that starts to rotate with a certain rotation torque or more. Have projections that mesh with each other and are axially separated from each other before the reel is rotated.The cam feed mechanism has a spiral groove and a spiral groove shaped to feed the ratchet to the axial start gear side by the forward rotation of the reel. A small engine with a starter, which comprises lead grooves that mesh with each other, and when the reel rotates normally, both projections are engaged by the axial movement of the ratchet and the starting gear is positioned at the recoil start position. 3. A starting shaft with a tubular portion fitted to the outer periphery of one end of the crank shaft in the crankcase via an one-way clutch so as to be axially movable between an electric starting position and a recoil starting position in the axial direction, and a starter. An electric starter having a starting gear fixed to a shaft, a recoil starter arranged concentrically with the starting shaft, and a gear arranged radially outward of the starting gear and meshing with the starting gear at the electric starting position, and a recoil starter. Ratchet that is fitted to the reel via a cam feed mechanism, a spring that biases the starting gear to the electric starting position, and an initial rotation that engages with the axial recess of the ratchet and starts to rotate at a certain rotational torque or more. It is equipped with a friction plate for stopping, and the starting gear and the ratchet face are opposed to each other by meshing with each other before the reel rotates. The cam feed mechanism has a spiral groove and a lead groove that meshes with the spiral groove that sends the ratchet to the starting gear side in the axial direction by the forward rotation of the reel. When rotating, the small engine with a starter is characterized in that both projections are engaged by the axial movement of the ratchet and the starting gear is positioned at the recoil starting position.