JPH0697024B2 - Starter for small engine - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a starting device for a small engine, and more particularly, to a starting device for a small engine that includes a recoil starter and a starter motor, and that the recoil starter and the starter motor start at the same time.

[Prior art]

Many small-displacement engines used as power sources for power sprayers and brush cutters, so-called small engines, are equipped with both a recoil starter or starter motor as a starting device, or an independent operation. During work, the rope of the recoil starter is pulled out vigorously or the starter motor is operated to rotate the crankshaft and start the crankshaft.

[Problems to be Solved by the Invention]

The starting device as described above is not a big problem when it is operated by an operator who has the strength to pull out the rope of the recoil starter vigorously, but in the case of a woman or an elderly worker, it exceeds the load of the compression process of the engine. It is very difficult to turn the crankshaft, and the starting work becomes a heavy burden. Also,
A starter motor that can be started requires a large capacity, that is, a large and heavy starter motor in order to rotate the crankshaft beyond the load of the compression stroke, and is installed in a portable work machine such as a power sprayer or a brush cutter. There were restrictions on equipping a small engine with a small displacement with a starter motor.

[Means for Solving the Problems]

Therefore, the present invention is equipped with a recoil starter and a starting motor in order to reduce the work load at the time of starting a small engine and the carrying load at the time of work, and the recoil starter and the starting motor work together to easily start the engine. It is intended to be able to perform work, for that purpose, in conjunction with the operation of pulling out the rope of the recoil starter, a starter switch of the starting motor that is closed immediately before the ratchet of the recoil starter is engaged with the ratchet of the crankshaft, The present invention is characterized in that the crankshaft is driven by the simultaneous cooperation of the rope pulling operation of the recoil starter and the output of the starter motor that rotates by closing the starter switch only when pulling the rope.

[Work]

With the above-described configuration, the starting device for a small engine of the present invention has the start switch of the starting motor turned on immediately before the crankshaft is rotated by the recoil starter by the operation of pulling out the rope of the recoil starter, and the turning force by the recoil starter and the start The output of the motor simultaneously drives the crankshaft to start the engine with a small force.

【Example】

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In FIG. 3, reference numeral 10 is an engine body unit mounted on the brush cutter, reference numeral 20 is a recoil starter unit,
Reference numeral 30 indicates a centrifugal clutch unit provided on the output shaft of the engine, and reference numeral 40 indicates a cell starter unit provided near the centrifugal clutch unit 30. As shown in FIGS. 1 to 7, the engine body unit 10 is configured such that one end of the crankshaft 11 has a function as a one-way clutch and can be engaged with and disengaged from the recoil starter unit 20. A clutch shoe that constitutes the centrifugal clutch 13 is attached to the other end. The recoil starter unit 20 is the engine body unit
Shaft provided at the center of the starter case 21 that can be attached to the 10
A reel 23 is rotatably attached to the reel 22, one end of the reel 23 is locked to the reel 23, and the other end of the recoil spring 24 is locked to the starter case 21. The rope 25 has a habit of rotating in the winding direction of the rope 25. A grip 25A serving as a grip when the engine is started is fixed to an end of the rope 25, and the reel 23 can be rotated by pulling the rope 25. This reel 23 has a cylindrical boss portion 23A at the center, and this boss portion 23A
A ratchet 26 as a feeding type one-way clutch having a spiral tooth 23B inside and a spiral groove 26A meshing with the spiral tooth 23B is fitted into the boss portion 23A, and the reel 2
3 and the ratchet 26 are connected by a spiral tooth 23B and a spiral groove 26A. The center of the ratchet 26 is in the shape of a hollow cylinder, and a concave groove 26B into which the projection 27A of the rotor 27 pivotally supported by the shaft 22 is fitted is formed on the inner surface of the ratchet 26. Friction behavior is provided by the spring 27B and the disc 27C that is bottle-fastened to the shaft 22, and the ratchet 26 is allowed to move in the axial direction. A ratchet pawl 26X is formed on the end face of the ratchet 26 so that the ratchet pawl 26X is engaged with the ratchet pawl (not shown) of the crankshaft 11 only when rotating in one direction. Early in the rotation of reel 23, spiral tooth 23B and ratchet 2
Because the spiral groove 26A of 6 meshes with the rotation direction,
Ratchet 26 tries to rotate with 23, but on the other hand,
The rotor 27 is frictionally fixed to the shaft 22 by the spring 27B and the disc 27C, and the ratchet 26 is formed in the rotor 27 with a groove.
Since the ratchet 26 and the protrusion 27A mesh with each other in the rotation direction, the ratchet 26 and the rotor 27 remain, and as a result, the ratchet 26 rotates with the rotation of the reel 23 and the spiral tooth 23B rotates and the spiral groove 2 moves.
Due to the feeding action that occurs when 6A is stored, the groove 26
While B is guided by the protrusion 27A, the ratchet 26 protrudes substantially linearly as shown by the chain double-dashed line in FIG. 1 until the inner bottom surface of the ratchet 26 contacts the disc 27C. When the reel 23 further rotates, the ratchet 26 and the rotor 27 rotate together with the reel 23 against the friction acting on the rotor 27. The ratchet 26 has a stopper 26Y for the end surface of the boss portion 23A of the reel 23, and one end portion 28A of the switch operating lever 28 is elastically contacted with the outside of the stopper 26Y. The switch operating lever 28 is pivotally attached to the starter motor switch 29 mounted inside the starter case 21, and the operator 29A outside the pivot point is the other end of the switch operating lever 28. It can be pressed with part 28B. The other end (output shaft) of the crankshaft 11 extends into the housing 12 mounted on one side of the engine body unit 10 and is supported by the crankcase of the unit 10 by the bearing 32, and It penetrates the boss 12A.
A large gear 33 is fitted in the boss portion 12A of the housing 12, a ratchet 34 having an elliptical fitting hole 34A is fitted in the large gear 33, and the fitting hole 34A is loosely fitted in the boss portion 33A. Installed. Then, a convex portion 33B that accommodates the torsion spring 34B is provided in the boss portion 33A, and is fitted in a concave portion 34C provided in the ratchet 34. An engaging groove 34D is provided around the ratchet 34, and the engaging groove 34D is provided in the boss portion 12A of the housing 12.
The claws 35A of the friction plate 35 fitted to the fitting plate are fitted, and the friction plate 35 is given a friction habit in the pushing direction by the pressing spring 35B. Furthermore, an engagement protrusion 34E is provided at a position about 90 degrees away from the engagement groove 34D of the ratchet 34, and the engagement protrusion 34E is attached to a boss portion 36A of a clutch shoe 36 described later. It is designed to hit the plywood 36B. Gear 3
At the initial stage of rotation of 3, the boss portion 33A of the large gear 33 is rotated by the action of the torsion spring 34B as shown by the solid line in FIG.
Is closer to the right side of the elliptical fitting hole 34A of the ratchet 34, the convex portion 33B of the large gear 33 is fitted in the concave portion 34C of the ratchet 34, so that the concave portion 34C side of the ratchet 34 tries to rotate together with the large gear 33. However, on the other hand, the engagement course of the ratchet 34
The claw 35A of the friction plate 35 is fitted to D, the friction plate 35 receives friction by the action of the pressing spring 35B, and does not rotate together with the large gear 33, so that the engagement mechanism 34D side of the ratchet 34 remains there. As a result, as shown by the chain double-dashed line in FIG. 7, the boss portion 33A of the large gear 33 is brought to a position closer to the left side of the elliptical fitting hole 34A of the ratchet 34,
The engagement protrusion 34E projects. When the large gear 33 further rotates, the ratchet 34 and the friction plate 35 rotate together with the large gear 33. A clutch drum 37 is arranged around the clutch shoe 36 to form a centrifugal clutch unit 13, and this clutch drum 37 is connected to a transmission shaft 38 of the brush cutter,
It is rotatably supported in the internal space of a pipe holder 31A that fixes the end of the operating main rod 39. And the clutch housing 3 integrated with the pipe holder 31A
1, a starter motor casing 31B is provided, a starter motor 41 that constitutes the cell motor unit 40 is housed therein together with a rechargeable battery 42, and an output shaft 41A of the starter motor 41 is the large gear 33. And a pinion 43 attached to the output shaft 41A of the starter motor 41 engages with the large gear 33.
It is designed to be rotated by closing 29. Next, the operation of actually operating the small engine starting device according to the present invention will be described. First, the rope 25 constituting the recoil starter is grasped by the grip 25A and pulled out vigorously, and the reel 23 is rotated. As the reel 23 rotates, a sending action of the ratchet 26 occurs between the spiral tooth 23B and the spiral groove 26A of the ratchet 26 meshing with the spiral tooth 23B.
The concave groove 26B formed on the inner surface of 26 is the protrusion 27A of the rotor 27.
The ratchet 26 is extended substantially linearly due to the fact that the ratchet 26 is fitted on the ratchet claw 26X, and the ratchet claw 26X tries to rotate the crankshaft 11 by meshing with the ratchet claw provided on the crankshaft 11. At this time, by the feeding action of the ratchet 26, the stopper 26Y is continuously extended together with the switch operating lever 28, and the starter motor switch 29 is turned on at the end portion 28B via the operator 29A. When the switch 29 for the starter motor is turned on, the starter motor 41 is rotated, and the pinion 43 provided on the output shaft 41A of the starter motor 41 is rotated.
Thus, the large gear 33 is started to rotate. Then, the ratchet 34 is biased against the torsion spring 34B to the state shown by the phantom line in FIG. 7, and the engaging projection 34E projects by Δl, and this engaging projection 34E is the boss portion 36A of the clutch shoe 36. The engaging plate 36B protruding from the above into the rotation region of the ratchet 34 is captured, and the starting torque is input to the crankshaft 11 via the boss portion 36A of the clutch shoe 36. In other words, as the rope 25 is pulled out by input and the reel 23 is rotated, the ratchet 26 is extended, the switch 29 is closed in the middle of this extension, and as a result, when the starter motor 41 rotates, it is passed through the pinion 43. The large gear 33 rotates, the ratchet 34 overhangs while rotating, and the engaging projection
When 34E abuts on the engagement plate 36B, ratchet approximately at the same time.
26 also engages with a ratchet pawl provided on the crankshaft 11. Then, the co-rotation of the reel 23 and the ratchet 26, and the co-rotation of the large gear 33 and the ratchet 34 are simultaneously performed, so that the crank shaft 11 and the engaging plate 36B, the boss portion 36A, and the crank shaft ( The output shaft) 11 is driven and the engine is started. When the engine starts, when the pulling of the rope 25 is stopped, the reel 23 reversely rotates by the recoil spring 24 and winds the rope 25, and the ratchet 26 is pulled back to release the engaged state and the switch is turned on. 29 is opened. At the same time, the rotations of the starter motor 41, the pinion 43, and the large gear 33 stop, and the ratchet 34 also stops with the engaging protrusion 34E overhanging. Then, as the crankshaft (output shaft) 11 rotates, the engaging plate 36B comes around and abuts against the back of the engaging protrusion 34E, and the action of the torsion spring 34B is also added to the engaging protrusion 34E. Of the engaging plate 36B is withdrawn from the rotation track of the engaging plate 36B. Note that, in the above description, an example in which the small engine starting device of the present invention is equipped in a brush cutter is given, but the invention is not limited to the brush cutter, and various small engines for mounting various portable working machines such as a power sprayer. Of course, it can be applied to.

【The invention's effect】

As is clear from the above description, according to the small engine starting device of the present invention, the power supply circuit of the starter motor is closed and rotated in association with the pulling-out operation of the rope, and the rotation torque of the recoil starter and the starter motor are increased. Since the rotation torque of the recoil starter is transmitted to the crankshaft at the same time and the crankshaft is driven to rotate, even if a weak woman who cannot pull the rope of the recoil starter at a stretch, a starter with a weak pulling force is used. The engine can be reliably started by operation. And since the start is due to the simultaneous cooperation of the recoil starter and the starter motor, the starter motor does not need a large and heavy one with a large capacity, but a small, light and small capacity is sufficient. The power consumption is low, the power source is light, and the burden of carrying it when it is mounted as a power source for portable working machines such as power sprayers and brush cutters can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a recoil starter portion of a small engine, FIG. 2 is a sectional view of the centrifugal clutch portion of the same, FIG. 3 is a side view of the small engine, and FIG. Fig. 1 is a sectional view taken along the line IV-IV in Fig. 1, Fig. 5 is a sectional view showing the relationship between a ratchet and a switch for a starter motor, and Fig. 6 is a sectional view taken along the line VI-VI in Fig. 2; Is the second
FIG. VII-VII is a cross-sectional view taken along the arrow. 10 …… Engine body unit 11 …… Output shaft, 12 …… Housing, 12A …… Boss part, 13
...... Centrifugal clutch 20 …… Recoil starter unit 21 …… Starter case, 22 …… Axis, 23 …… Reel, 23A
...... Boss part, 23B ...... Spiral tooth, 24 ...... Recoil spring, 25
…… Rope, 25A …… Grip, 26 …… Ratchet, 26A
... spiral groove, 26B ... concave groove, 26X ... ratchet claw, 26Y
...... Stopper, 27 ...... Rotor, 27A ...... Protrusion, 27B ...... Spring, 27C ...... Disc, 28 ...... Switch operating lever, 28A, 28B
...... End, 29 …… Starter motor switch, 29A ……
Operator 30 …… Centrifugal clutch unit 31 …… Clutch housing, 31A …… Pipe case holder, 31B …… Starter motor casing, 32 …… Bearing, 3
3 …… Large gear, 33A …… Boss part, 33B …… Convex part, 34 …… Ratchet, 34A …… Mating hole, 34B …… Torsion spring, 24
C: recess, 34D: engaging groove, 34E: engaging protrusion, 35:
Friction plate, 35A ... Pawl, 35B ... Press spring, 36
...... Clutch shoe, 36A ...... Boss part, 36B ...... Engagement plate,
37 …… Clutch drum, 38 …… Transmission shaft, 39 …… Operating main rod 40 …… Cell starter unit 41 …… Starter motor, 42 …… Rechargeable battery

Claims (1)

[Claims] 1. A small engine equipped with a recoil starter and a starter motor, wherein the starter motor is closed immediately before the ratchet of the recoil starter meshes with the ratchet of the crankshaft in conjunction with the operation of pulling out the rope of the recoil starter. Equipped with a starting switch, rope pulling operation of recoil starter,
A starting device for a small engine configured to drive the crankshaft simultaneously with the output of a starting motor that rotates by closing the starting switch only when the rope is pulled.