JPH0123643B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a starter-linked decompression device used in an engine equipped with a decompression device in a motorcycle or the like.

When a motorcycle engine equipped with a kick-type starter has a single cylinder and a large displacement, the resistance during the compression stroke is large, so a large force is required when depressing the kick pedal. Moreover, its operation requires skill. For this reason, various methods have been proposed for performing the decompression operation in conjunction with the kick operation, but since it is difficult to synchronize the timing of these two operations only with manual operation, the An improved starter-linked decompression device has been proposed in which the decompression operation is automatically and synchronously performed when the kick pedal is depressed.

This conventional decompression device uses a double-structured cam mechanism consisting of a large-diameter cam part and a small-diameter cam part, and the cam follower engages with the large-diameter cam part during the forward stroke of operating the kick pedal to perform the decompression action. Then, during the return stroke, the cam follower is engaged with the small diameter cam part to release the decompression and return to the original starting position, and then it is slid in the direction of the shaft again to reach the position where decompression is possible. This means that it will be reset to .

However, this device requires the cam mechanism to have a complicated double structure, and it also has to slide in the axial direction of the lock shaft, making the mechanism complex and requiring a large amount of space in the axial direction. There is a drawback. In particular, this mechanism is extremely disadvantageous for engines with limited space, such as those used in motorcycles. In addition, since friction occurs due to sliding, it becomes difficult to press the kick pedal, which inevitably has the disadvantage of hindering light operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a starter-linked decompression device that occupies a small space in the axial direction of a kick shaft and that does not involve sliding when the pedal is depressed, thereby allowing easy operation.

The present invention achieves the above object by providing a protrusion 2 on the kick shaft 1 to which an elastic rotational force is applied in the anti-kicking direction.
A shaft 6 which fixes the decompression cam 2 having the decompression cams 2A and 2B, and which also receives elastic rotational force in the anti-kick direction and operatively connects the decompression wire 10 which exerts a pressure reduction operation on the exhaust valve 12 or the pressure reduction valve.
The swing levers 5, 5A, 5B are fixed to the swing levers 5, 5A, 5B.
The contacts 7, 26, 26B are arranged so as to face within the locus of movement of the protrusions 2a, 2B, and are attached so that they can move integrally and move relative to each other, and can be returned to their original positions by elastic force. It is something to do.

The following will explain the embodiments shown in the figures.

FIG. 1 shows the upper structure on the operated side of the decompression device of the present invention, and FIGS. 2 to 4 show the lower structure on the operating side.

On the operated side in FIG. 1, 12 is an exhaust valve provided so as to penetrate the cylinder head 11 of the engine into the combustion chamber, and this exhaust valve 12 is opened and closed by the rocker arm 13 swinging. . A contactor 14 is attached to the tip of this rocker arm 13.
are engaged, and this contactor 14 is fixed to the swing arm 15. Furthermore, the inner wire 10' of the decompression wire 10 is connected to the swing arm 15,
This inner wire 10' extends toward the operation side shown in FIGS. 2-4. 16 is a rubber covering material that covers the inner wire 10'.

In such a configuration, the inner wire 1
0' is pulled in the direction of arrow D' from the operating side, the swinging lever 15 swings in the direction of arrow E, and the contactor 14 pushes the exhaust valve 12 in the direction of arrow F. The inside of the cylinder is decompressed.
In this embodiment, the exhaust valve is pushed in to decompress, but a pressure reducing valve may be provided separately from the exhaust valve to perform the same operation.

On the other hand, on the operating side shown in FIGS. 2 to 4,
Reference numeral 1 denotes a kick shaft, and a kick crank 17 is fixed to the end projecting outward, and a kick pedal (not shown) is attached to the end of the kick crank 17. By depressing this kick pedal, rotation can be given to the kick shaft 1. A decompression cam 2 having a protrusion 2a is fixed to the decompression shaft 1, and a tension spring 18 is tensioned between the decompression cam 2 and a pin 19 implanted in the casing. An elastic rotational force is applied.

Further, a gear 20 is loosely fitted onto the crankshaft 1 and is adapted to interlock with a crankshaft (not shown). There is a latch 2 on the side of this gear 20.
0' is provided, and this latch 2
A ratchet wheel 3 is provided on the kick shaft 1 on the side facing 0'. This ratchet wheel 3 is slidable in the axial direction by a spline, and its ratchet 3' faces the ratchet 20' of the gear 20. The ratchet wheel 3 is biased in the direction of arrow B by the compression spring 21, but at the same time, it is restricted from moving toward the gear 20 by the guide plate 4 (Figs. 2 and 4). When the shaft 1 rotates beyond a certain range, the restriction is released and the shaft 1 moves in the direction B, meshing with the gear 20 and rotating a crankshaft (not shown).

On the other hand, a shaft 6 is rotatably supported adjacent to the above-mentioned kick shaft 1, and is biased with an elastic rotational force toward the opposite side by a winding spring 33. This axis 6
A swing lever 5 is fixed to the inner end side of the
It comes into contact with the stopper 24 due to the elastic rotational force. Further, a lever 9 is fixed to the outer end side of the shaft 6, and this lever 9 is connected to the aforementioned lever 15 on the operated side via a decompression wire 10.

The swing lever 5 also includes a decompression cam 2.
A contact 7 is rotatably provided via a pin 8 on the side facing the contact 7, and is biased in one direction by a winding spring 23. That is, as shown in detail in FIGS. 5 and 6, the contactor 7 has a bent stopper 7a, and this stopper 7a is inserted into a fan-shaped hole 5a drilled on the swing lever 5 side, and the spring is inserted into the fan-shaped hole 5a. By being biased by 23, it is brought into contact with one inner edge of the hole 5a. Further, in such a configuration, the tip of the contactor 7 is positioned within the rotation locus of the protrusion 2a of the decompression cam 2.

In the starter-linked decompression device of the present invention described above, the starting operation is performed as follows.

First, when the kick pedal at the tip of the kick crank 17 is depressed, the kick shaft 1 rotates in the direction of arrow A, and the decompression cam 2 also rotates in the direction of arrow A'. As the decompression cam 2 rotates, the projection 2a flips the tip 7b of the contact 7, causing the contact 7 to rotate, and the contact 7 also pushes the stopper 7a into the hole 5a.
2, the swinging lever 5 is rotated, and the lever 9 is rotated via the shaft 6 in the direction of arrow C in FIG. Therefore, the inner wire 10' of the decompression wire 10 is pulled in the direction of arrow D, and the operated side is pulled in the direction of arrow D' in FIG. It is pushed down as shown by arrow F to decompress the inside of the cylinder. In the above decompression operation, when the protrusion 2a of the decompression cam 2 passes the tip 7b of the contact 7, the swing lever 5 is reversed by the biasing force of the spring 33 and returns to the position where it contacts the stopper 24 again.

On the other hand, since the ratchet wheel 3 also rotates along with the decompression operation described above, the protrusion 3a comes off from the guide plate 4 after rotating by a predetermined angle, and the ratchet wheel 3 moves as shown by arrow B in FIG. 3' to ratchet 2 of gear 20
0' and rotate the gear 20. Therefore, the crankshaft (not shown) is rotated under the above-described decompression state, and the engine is started.

The above steps are carried out during the forward stroke of depression of the kick pedal, but when the pedal is released, the kick shaft 1 is automatically reversed by the force of the spring 18 to rotate in the opposite direction. Due to this reversal of the kick shaft 1, the decompression cam 2 is also reversed to its original position. In the return stroke due to this reverse rotation, the tip 7 of the contactor 7
b is repelled by the protrusion 2a, but at this time, the contact 7 moves the stopper 7a inside the hole 5a of the swing lever 5 to the opposite side, so it is not engaged with the swing lever 5. Therefore, the swing lever 5 remains in contact with the stopper 24, and only the contact 7 swings. When the protrusion 2a comes out of contact, the urging force of the spring 23 returns it to its original position in contact with the inner edge of the hole 5a.

7 to 10 show a second embodiment of the present invention, in which a swinging lever 5A is fixed to a shaft 6A, and a roller-shaped contact 26 is inserted into a guide hole 25 provided in the swinging lever 5A. is inserted, and its contact 26 is biased toward one end of the guide hole 25 by a spring 23A.

In this embodiment, as shown in FIGS. 9 and 10, the decompression cam 2A rotates in the direction of arrow A' and the protrusion 2B hits the contact 26, thereby moving the contact 26 to the position 26'. move to position.
Thereby, the swinging lever 5A is rotated, and in order to rotate the lever 9A to the position 9A', the inner wire 10' connected to this lever 9A is pulled in the direction of arrow D, and the exhaust valve 12 of FIG. is moved in the direction of arrow F to decompress the inside of the cylinder.

11 and 12 show a third embodiment of the present invention. In this embodiment, a roller-shaped contact 26B is positioned in the middle of the guide hole 25B of the swing lever 5B. I have to. The swinging lever 5B has a bent tongue 27 protruding from the center thereof, and springs 23B extending along both sides of the tongue 27 support the contact 26B at the intermediate portion. There is.

Therefore, when the contact 26B is pushed by the protrusion of the decompression cam 2 and moves along the guide hole 25B, the elastic force of the spring 23B acts, and after it has moved to a certain extent, the swing lever 5B begins to swing. ing. After this movement of the swing lever 5B, the decompression action is performed in the same manner as in the above-described embodiment.

In this embodiment, the contact 26B is inserted into the guide hole 25.
Since it is elastically supported by a spring 23B at the middle part of the contactor B, no impact noise is generated due to the collision between the contactor 26B and the swing lever 5B.

As described above, in the present invention, the protrusion 2a,
While fixing the decompression cam 2 having a decompression cam 2B, a swing lever is attached to the shaft 6 to which the decompression wire 10, which is similarly applied with an elastic rotational force in the anti-kick direction and which exerts a pressure reduction operation on the exhaust valve 12 or the pressure reduction valve, is interlocked and connected. 5, 5A, 5B are fixed, and the contacts 7, 26, 26B, which face the movement locus of the protrusions 2a, 2B of the decompression cam 2, are integrally moved on the swing levers 5, 5A, 5B. The decompression cam 2 is characterized by being mounted so that it can be moved relative to the other and returned to its original position by elastic force.With this configuration, the decompression cam 2 has a simple protrusion 2 on the outer periphery of a plate-shaped cam plate.
It becomes sufficient to simply form a and 2B.

Therefore, the decompression cam can be obtained by extremely simple processing, and does not require complicated processing unlike conventional double-structured cams. In addition, by using the swing levers 5, 5A, 5B and the contacts 7, 26, 26B that are movable relative to the swing levers, there is no need for sliding in the direction of the shaft axis, and the space in the axial direction is small. I will come to live. Therefore, it is extremely suitable for engines with limited space, such as motorcycles. Furthermore, since there is no friction during sliding operation, the jerking operation can be made easier.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, and Figs. 1 to 6 show a starter-linked decompression device according to an embodiment of the present invention, and Fig. 1 shows the upper structure of the device, which is the operated side. Figure 2 is a sectional view of the main parts of the lower structure on the operating side, Figure 3 is a plan sectional view showing details of the operating side, and Figure 4 is a view taken from a 90° different direction from Figure 3. 5 is a front view of the swing lever assembly used on the operating side, and FIG. 6 is a side view of the same. 7 and 8 are front and side views of a swing lever assembly according to a second embodiment, and FIG. 9 is a front view showing essential parts of a decompression device using the swing lever assembly, FIG. 10 is a sectional view of the same plane. 11 and 12 are a front view and a side sectional view of a swing lever assembly according to a third embodiment. 1... Hard shaft, 2, 2A... Decompression cam,
3...Ratchet wheel, 3'...Ratchet,
4... Guide plate, 5, 5A, 5B... Rocking lever, 6... Shaft, 8... Pin, 7, 26, 26B...
...Contact, 9,9A...Lever, 10...Decompression wire, 11...Cylinder head, 12...Exhaust valve, 15...Lever, 17...Kit crank, 20...Gear, 20'...Ratchet .

Claims (1)

[Claims] 1. A decompression cam 2 having protrusions 2a and 2B is fixed to the kick shaft 1 to which an elastic rotational force is applied in the anti-kick direction, while an elastic rotation force is also applied in the anti-kick direction and the exhaust valve 12 is fixed. Alternatively, the swinging levers 5, 5A, 5B are fixed to the shaft 6 that interlocks and connects the decompression wire 10 that exerts a pressure reduction operation on the pressure reducing valve, and the protrusion 2a of the decompression cam 2, A starter-linked decompression device in which contacts 7, 26, 26B facing the movement locus of 2B are attached so that they can move together and relative to each other and can be returned to their original positions by elastic force.