JPH03258969A - Starter device of miniature engine - Google Patents

Abstract

PURPOSE:To prevent the reverse rotation of a motor by starting a clutch plate and a centrifugal ratchet as they are in normal engagement at the time of positive rotation, and releasing the engagement by a release cam rotatable only in positive rotating direction by a one-way clutch when the engine rotates reversely. CONSTITUTION:When a motor 14 is rotated, a final gear 6 is rotated to rotate a clutch plate 9, which pushes and rotates a release cam 10. At this time, the engagement part 9b of the clutch plate 9 is engaged with a centrifugal ratchet 18, and an engine starts rotating. After starting, the engagement is released. In the case of reverse rotation at the time of en-st by engine overload and stop, the ratchet 18 is pushed inward by a return spring 19 as the centrifugal force of the ratchet 18 is reduced, and the clutch plate 9 engaged with the ratchet 18 starts to resversely rotate. As a cam 10 never reversely rotate due to a one-way clutch 11, then, the ratchet 18 is pushed outward against a spring 19 on the inclined surface 10a of the cam 10, and the engagement with the clutch plate 9 is released, so that the gear 6 is never reversely rotated even if the engine continues reverse rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a starting device for an electric starter motor (starter motor) used as a starting device for a small engine.

(Conventional technology) Various methods of transmitting power from the starter motor to the engine have been devised in the past, but the ventix type was generally used.However, this method causes a large shock when the pinion gear jumps. To solve this problem, a solenoid, etc. is used, which is very expensive, and in the case of a constant mesh type, the starter stops the engine from reversing, which can cause damage to gears, etc. However, recently, In order to provide inexpensive and compact electric starters, centrifugal ratchets are increasingly used in clutch mechanisms.

(Problem to be solved by the invention) For example, when a clutch mechanism other than a centrifugal clutch is used to transmit power from the engine to the work equipment (in most cases other than extremely small engines), the engine may be overloaded due to overload during work. Sometimes the engine stalls (stops).At this time, ■In the case of belt transmission, etc., if the belt is abnormally stretched and the engine succumbs to the load and stops, the engine will suddenly stop as the belt tries to shorten. In addition, the centrifugal ratchet mechanism that transmits power from the starter to the engine becomes engaged when the engine stops momentarily, so the starter receives this shock, which can cause major damage, etc. There was a problem.

Therefore, an object of the present invention is to provide an electric starting device that uses a centrifugal ratchet as a ratchet mechanism for starting an engine from a starting device, so that the centrifugal ratchet can be forcibly engaged even if the engine reverses. The present invention aims to provide a starting device for a small engine that can be removed.

(Means for Solving the Problems) In order to achieve the above object, a starting device of the present invention will be explained based on the drawings. In the first construction drawing, a one-way clutch 16 is included in a part of the reduction gear 15 of the starting motor 14,
This starting device transmits rotation by a centrifugal ratchet 18 provided on a pulley 17, and a release cam 10 is provided outside the clutch plate 9 that engages with the centrifugal ratchet 18 on the support shaft of the final gear 6 in the reduction gear 15. A housing portion for a damper 7 and a release spring 8 is provided on one side of the final gear 6, separated by a stopper 6a. Further, the clutch plate 9 has a protrusion 9a on one side that is connected to the final gear 6.
On the other hand, a convex part is attached to the pulley 17 and has an engaging part 9b with the centrifugal ratchet 18, and a convex part 9c that fits into the guide hole 10b of the release cam 10 is integrally provided at the tip. A one-way clutch 11 is press-fitted into the inner diameter of the release cam 10, and a plurality of inclined surfaces 10a are provided on the flange thereof.

Then, the starter rotates in the normal rotation direction (in the starting direction, the clutch plate 9 and centrifugal ratchet 18 should be started with the clutch plate 9 and centrifugal ratchet 18 in normal engagement. See Figure 2). If the engine is reversed due to overload, etc. while the engine is running, the one-way clutch 11 will rotate the starter in the normal rotation direction. The ratchet plate 9 and the centrifugal ratchet 18 are forcibly disengaged by a release cam 10 which rotates only in the direction of rotation (see FIG. 4).

(Function) In the above configuration, when the motor 14 starts rotating, the final gear 6 rotates via the reduction gear 15, and the clutch plate 9 rotates via the release spring 8 or the damper 7.
rotates, and the release cam 10 is further pushed by the protrusion 9c and rotates. At this time, the positional relationship among the final gear 6, clutch plate 9, and release cam 10 is as shown in FIGS. 2 and 3. Therefore, the meshing portion 9b of the clutch plate 9
The centrifugal ratchet 18 is engaged, the release spring 8 is compressed by the resistance of the engine, the damper 7 is compressed, and the engine stops rotating. Note that when the engine is started, the centrifugal ratchet 18 is pushed outward against the return spring 19 by centrifugal force, and is disengaged.

After starting, if the engine stalls due to overload or reverses when stopped, the engine decelerates, so the centrifugal force of the centrifugal ratchet 18 decreases and is pushed inward by the return spring 19, and when the engine starts to reverse. , the centrifugal ratchet 18 engages with the clutch plate 9, and the clutch plate 9 begins to reverse rotation.

At this time, since the clutch plate 9 is in front of the final gear 6 in the forward direction due to the release spring 8, only the clutch plate 9 rotates in reverse against the release spring 8 (see Figures 4 and 5). .

At this time, the release cam 10 is locked in the reverse direction by the one-way clutch 11 and does not rotate, so the centrifugal ratchet 18 is pushed outward against the return spring 19 by the inclined surface 10a of the release cam 10, and the clutch plate 9 The final gear 6 is disengaged (see Fig. 4), and even if the engine continues to rotate in reverse, the final gear 6 will not be reversed.

(Example> Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the small engine of the present invention;
Figure 2 is a sectional view taken along ■--■ at the time of startup in Figure 1, and Figure 3 is the same <II-I sectional view.The figure shows the coil starter and cell starter integrated, but the cell starter alone can also be used. good.

As shown in the figure, a reel 3 is loosely inserted into a shaft 1a provided integrally with the case 1, a rope 4 is wound around the reel 3 in a rope winding groove, and one end of the row 14 is inserted through the rope of the case 1. The rope 4 is pulled out from the hole, and a knob (not shown) is attached to the end of the rope so that the rope 4 can be easily pulled out. Furthermore, a ratchet 5 is provided on one inner side of the reel 3 to transmit rotation in only one direction. A mainspring 2 is housed in a recess in the case 1 between the case 1 and the reel 3, and is energized to wind up a rope 4 with a reel 3. Two shafts 12 are fixed to the tip of the shaft 1a with screws,
A clutch plate 9 and a final gear 6 are inserted into the outer periphery of one of the shafts 12, and a release cam 10 is inserted into the other shaft 12.

A housing portion for a damper 7 and a release spring 8 is provided on one side of the final gear 6 (see FIG. 3), and these are stored separated by a stopper 6a. A protrusion 9a is provided on one side and protrudes into the housing portion of the final gear 6. On the other side,
A convex portion is provided that has an engaging portion 9b (see Fig. 2) with the centrifugal ratchet 18 attached to the pulley 17.Furthermore, the tip thereof has a guide hole 10b of the release cam 10.
A protrusion 9c to be fitted is integrally provided. Note that a one-way clutch 11 (
(see FIG. 1) is press-fitted and fixed, and the collar portion is provided with a plurality of inclined surfaces 10a.

The pulley 17 is fixed to the crankshaft 20 of the engine by screws or the like, and a centrifugal ratchet 18 biased inwardly by a return spring 19 is attached to one side of the pulley 17. Further, a motor 14 is attached to the gear cover 13, and a reduction gear 15 is attached to the opposite side.
is pivotally supported between the case l and one of the reduction gears is provided with a one-way clutch 16 fixed by press-fitting or the like. Further, the gear cover 13 is screwed together with the case 1 to the crankcase 21 of the engine.

Next, its operation will be explained.

When the rope 4 is pulled out, the reel 3 rotates against the separator 2, and the ratchet 5 attached to the reel 3 (transmits rotation only in one direction) rotates the final gear 6, which releases the release spring 8 or damper 7. The rotation is transmitted to the clutch plate 9 through the clutch plate 9, and the release cam 1o is further pushed by the protrusion 9c and rotated. Final gear 6 at this time
, the positional relationship between the clutch plate 9 and the release cam 10 is as follows.
As shown in Figures 3 and 3. Therefore, the engaging portion 9b of the clutch plate 9 is exposed in the direction of engagement with the centrifugal ratchet 18, so when the clutch plate 9 and the release cam 1o start rotating, the centrifugal ratchet 18 and the clutch plate 9 at an arbitrary position are exposed. are engaged, the release spring 8 is compressed by the resistance of the engine, and the damper 7 is compressed (the fifth
(see figure), the engine stops rotating.

When the engine moves and the rope 4 is returned, the mainspring 2 causes the reel 3 to rotate the row 14 in the unwinding direction, and the rope 4
is wound up. At this time, the ratchet 5 does not mesh with the final gear 6 (it meshes only in the forward rotation direction). Furthermore, when the final gear 6 rotates normally, the one-way clutch 16 fixed to one of the reduction gears 15 prevents the rotation from being transmitted to the motor side. Note that when the engine starts, the centrifugal ratchet 18 releases the return spring 19 due to centrifugal force.
It is pushed outward against the force, and the occlusion is disengaged.

Next, when starting with the motor 14, when the motor 14 starts rotating, the transmission is transmitted by the reduction gear 15, the final gear 6 rotates, and the engine starts with the same thread path as the transmission beam coil starter. Note that at this time, since the ratchet 5 does not mesh with the recoil side, no rotation is transmitted to the reel 3. Further, the one-way clutch 16 of the reduction gear 15 transmits the transmission because it is in the meshing direction.

After starting, if the engine stalls due to overload or reverses when stopped, centrifugal ratchet 1
When the centrifugal force of 8 decreases and is pushed inward by the return spring 19, and the engine starts to rotate in reverse, the centrifugal ratchet 18 engages with the clutch plate 9, and the clutch plate 9
begins to reverse. At this time, since the clutch plate 9 is in front of the final gear 6 in the normal rotation direction due to the release spring 8, only the clutch plate 9 rotates in reverse against the release spring 8 (FIGS. 4 and 5). At this time, the release cam 10 is locked in the reverse direction by the one-way clutch 11 and does not rotate, so the centrifugal ratchet 1
8 is pushed outward against the return spring 19 by the inclined surface 10a of the release cam 1o, disengaging from the clutch plate 9 (see Fig. 4), and the above state is repeated even if the engine continues to rotate in reverse. The final gear 6 will not be reversed by the rotation alone.

(Effects of the Invention) Since the present invention is configured as described above, it produces effects as described below.

The present invention uses a simple centrifugal ratchet type clutch mechanism.
In addition, we have installed a reversal prevention mechanism to prevent the gears and motor from reversing even if the engine is reversed.
It is safe without being trapped. In other words, even when the engine is momentarily stopped, the centrifugal ratchet and clutch plate are once engaged, but since there is play in the rotational direction between the clutch plate and the final gear, the centrifugal ratchet is forcibly disengaged during this time using a release cam. In order to release the engine, the gears, motor, etc. do not rotate in reverse at all, so each part only needs to be strong enough to withstand the start. Also, when the engine is stopped, the compression stroke is reversed, but at this time, no shock occurs at all due to the above-mentioned mechanism. Depending on the condition of the engine, reversal may occur when starting, but in the present invention, when a large load is applied due to reversal, the tamper is compressed and the centrifugal ratchet is forcibly disengaged during this time. Therefore, there is no heavy load on the gears, etc., and no stress is placed on the motor, and at the same time, even when starting by pulling the rope with recoil, the rope will not be pulled in by the engine reversing, making it safe and An inexpensive starting device is obtained.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the starting device of the present invention;
The figure is the I-II sectional view at the time of starting in Figure 1, Figure 3 is the same <II-I sectional view, and Figure 4 is Figure 1 showing operation #jC state when the engine stalls or stops due to overload. I-I
The sectional view and FIG. 5 are similarly sectional views. 1... Starter case, 6... Final gear, 7
...Damper, 8...Release spring, 9...
Clutch plate, 10... Release cam, 11... One-way clutch, 12... Shaft, 14... Motor, 15... Reduction gear, 16... One-way clutch, 17... Pulley, 18 ...Centrifugal ratchet, 2
0...Crankshaft. Figure 1 5 -11 nog in the afternoon

Claims (1)

[Scope of Claims] (a) A starting device for a small engine that has a one-way clutch as a part of the reduction gear of the starting motor and transmits rotation by a centrifugal ratchet provided on a pulley, (b) said reduction gear A release cam (10) is provided on the spindle of the final gear (6) outside the clutch plate (9) that engages with the centrifugal ratchet (18), and (c) a damper is provided on one side of the final gear (6). (7)
and a release spring (8), each of which is separated by a stopper (6a), and (d) the clutch plate (9) has a protrusion (9a) on one side of the final gear (6). The other side has a convex part that protrudes into the storage part and has a convex part (9b) that is attached to the pulley (17) and engages with the centrifugal ratchet (18), and further has a guide hole (10b) for the release cam (10) at the tip. The protrusion that fits with (
9c) are integrally provided, (e) a one-way clutch (11) is press-fitted into the inner diameter part of the release cam (10), and a plurality of inclined surfaces (10a) are provided on the collar part, (f) When rotating in the forward direction, the clutch plate (9) and centrifugal ratchet (18) start with normal engagement, but if the engine is running in reverse due to overload, etc., the one-way clutch (11) will only rotate in the forward direction. A starting device for a small engine in which a clutch plate (9) and a centrifugal ratchet (18) are forcibly disengaged by a release cam (10) which is arranged so that the clutch plate (9) and the centrifugal ratchet (18) do not engage with each other.