JPH041189B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a kick-type starting device used in an engine equipped with a V-belt automatic transmission.

[Prior Art] A V-belt automatic transmission connects a drive pulley directly connected to the crankshaft of an engine and a driven pulley on a driven shaft with a V-belt, and adjusts the speed of the drive pulley to the pulley according to the rotational speed of the crankshaft. The gear ratio is automatically changed by changing the winding diameter of the V-belt.

By the way, when incorporating a kick-type starting device into an engine equipped with this type of V-belt automatic transmission, for example, as shown in "Utility Model Publication No. 53-58232," A kick shaft is provided on the case cover that covers the transmission, coaxially with the crankshaft, and a starting dog gear is provided at the end of the starting dog gear, and a starting dog gear is provided at the end of the crankshaft facing the starting dog gear. Another dog gear is provided, and when the kick crank is stepped down to rotate the crankshaft, the starting dog gear on this kickshaft jumps into engagement with the dog gear on the crankshaft side, and the rotation of the kickshaft is transferred to the crankshaft. There are several ways to convey this information.

In this starter, in order to increase the rotation speed of the crankshaft and transmit it to the crankshaft, a first speed increasing gear is engaged with a spline on the crankshaft, and a case is installed behind the crankshaft. An intermediate shaft is provided that spans between the cover and the transmission case, and a second speed-increasing gear that meshes with the first speed-increasing gear and a second speed-increasing gear that rotates together with the second speed-increasing gear are mounted on the intermediate shaft. Three speed increasing gears are arranged in the axial direction, and this third speed increasing gear meshes with the circumferential surface of the starting dog gear.

Therefore, when you step down on the hard crank,
The rotation of the kick shaft is sequentially increased in speed by the first to third speed increasing gears and transmitted to the starting dog gear.

[Problems to be Solved by the Invention] However, in the conventional configuration, the rotation of the kick shaft is first transmitted to the speed increasing gear on the rear intermediate shaft, and then again to the starting dog gear on the rear intermediate shaft. Since it is necessary to arrange the two speed increasing gears side by side in the axial direction, the axial length of the intermediate shaft must be made correspondingly longer.

For this reason, the case cover protrudes laterally at the intermediate shaft portion, which poses a problem that prevents the engine from being made smaller and lighter.

Moreover, since the intermediate shaft spans between the case cover and the transmission case, a bearing section for the intermediate shaft must also be provided on the transmission case side, which poses the problem of complicating the configuration of the transmission case. .

At the same time, the diameter of the V-belt of the V-belt automatic transmission that wraps around the pulley changes sequentially depending on the rotation speed of the crankshaft, so the intermediate shaft straddles between the case cover and the transmission case as described above. Therefore, if the V-belt crosses between the tension side and the slack side, the V-belt and the intermediate shaft are more likely to interfere with each other.

Therefore, there are significant restrictions on the installation position of the intermediate shaft, and depending on the position of the intermediate shaft, V
There is also a possibility that the gear ratio of the belt automatic transmission may be adversely affected.

Additionally, if the intermediate shaft is also supported on the transmission case side, the intermediate shaft and case cover must be aligned with high precision, especially when attaching the case cover, which requires more effort to attach and detach the case cover. Then there are some problems.

The present invention was developed based on these circumstances, and it is possible to minimize the sideward protrusion of the case cover, thereby making it possible to make the engine more compact, and also to reduce the effort required to attach and detach the case cover. First, an object of the present invention is to provide a kick-type starting device for an engine, which allows easy maintenance and inspection of a V-belt automatic transmission and the entire device, and also increases the degree of freedom in the mounting position of a kick shaft.

[Means for Solving the Problem] Therefore, in the present invention, a driven shaft parallel to the crankshaft is provided at the rear end of the transmission case extending rearward from one side of the crankcase, and a driven shaft located on this driven shaft is provided. A V-belt automatic transmission is constructed by winding a V-belt between the driven pulley and the drive pulley driven by the crankshaft,
In an engine in which the V-belt automatic transmission is surrounded by a case cover attached to the side openings of the crankcase and transmission case, the V-belt automatic transmission is located on the driven shaft between the driven pulley and the case cover. A centrifugal clutch is provided to connect and disconnect the rotation of the driven pulley to the driven shaft, and the case cover is provided with a centrifugal clutch extending between the centrifugal clutch and the crankshaft located in front of the case cover. One end of the shaft is led out into a space surrounded by the case cover and the transmission case, and the other end led out to the outside of the case cover is connected to a crankshaft, which is coaxial with the crankshaft. A starting dog gear that engages with a dog gear provided at the end of the crankshaft so as to be removably engaged with the dog gear provided on the end of the crankshaft, and a starting dog gear that rotates integrally with the starting dog gear are provided. The present invention is characterized in that a speed increasing helical gear is provided, and this speed increasing helical gear is always meshed with a helical gear provided at one end of the kick shaft inside the case cover.

[Function] According to this configuration, when the kick crank is stepped down, the rotation of the kick shaft is increased in speed and transmitted to the starting dog gear in front via a pair of mutually meshing helical gears, which is faster than before. This simplifies the rotational force transmission path, and eliminates the need to install two gears axially side by side on a shaft located on this transmission path, which reduces the length of the stiff shaft and support shaft. It can be kept short.

Moreover, since both the lock shaft and the support shaft are supported on the case cover side, this also contributes to shortening the shaft length, and there is no need to provide a special bearing part on the transmission case side, simplifying the structure. can be converted into

Also, between the case cover and the driven pulley,
The centrifugal clutch is located there, but the pivot shaft supported by this case cover is located in front of the centrifugal clutch, avoiding the centrifugal clutch, so the pivot shaft and the centrifugal clutch do not interfere with each other, and the pivot shaft One end of the centrifugal clutch can be inserted further inside the case cover than the outer surface of the centrifugal clutch. Therefore, the bearing part of the shaft on the case cover side can also be extended inside the case cover.
It is possible to ensure a sufficient bearing length for the lock shaft, and to prevent the case cover from protruding laterally at the bearing portion of the lock shaft.

Therefore, there is no need to arrange two gears on the support shaft as described above, and the case cover can be formed compactly, making it possible to downsize the engine.

Furthermore, since the screw shaft does not need to cross the V-belt, the screw shaft can be arranged without being influenced by the insertion position of the V-belt or the position of the pulley, increasing the degree of freedom in the layout of the screw shaft.
Therefore, it is possible to arrange the lock shaft sufficiently close to the support shaft, and the diameters of the helical gears that mesh with each other can be reduced.

In addition, since all the transmission lines for increasing the speed and transmitting the rotation of the crankshaft to the crankshaft are attached to the case cover side, attaching and detaching the case cover does not require any effort, and the work is as simple as removing the case cover. The V-belt automatic transmission and the starter can be separated from each other and exposed, making maintenance and inspection work easier.

[Embodiment] An embodiment of the present invention will be described below based on drawings in which the present invention is applied to a two-stroke engine for a motorcycle.

A crankshaft 1 is rotatably supported in a crankcase indicated by reference numeral 1a in the figure, and this crankshaft 1 is connected to a piston 3 of a cylinder 2 via a connecting rod 4. A transmission case 5 extending rearward is provided at one end of the crankcase 1a.
are integrated. A driven shaft 16 parallel to the crankshaft 1 is rotatably supported at the rear end of the transmission case 5, and the driven shaft 16 and the crankshaft 1 are interlocked via a V-belt automatic transmission 6. There is.

This V-belt automatic transmission 6 is constructed by winding an endless V-belt 10 between a drive pulley 7 driven by the crankshaft 1 and a driven pulley 21 provided on a driven shaft 16.

In other words, the drive pulley 7 has a V-shaped groove 9 formed by a fixed pulley plate 7a and a movable pulley plate 7b, and one end of the V-belt 10 is wound around this V-shaped groove 9. The fixed pulley plate 7a is fixed to the crankshaft 1, and the movable pulley plate 7b is movable in the axial direction relative to the crankshaft 1 in order to vary the groove width of the V-shaped groove 9. It is provided so that it can rotate freely in the rotational direction.

A support plate 11 that rotates together with the crankshaft 1 is fixed to the back of the movable pulley plate 7b, and between these support plates 11 and the movable pulley plate 7b,
A centrifugal weight 12 made of balls, rollers, etc. is interposed. As the rotational speed of the crankshaft 1 increases, the centrifugal weight 12 is moved radially outward by centrifugal force, and this movement presses and displaces the movable pulley plate 7b toward the fixed pulley plate 7a. The width of the V-shaped groove 9 is reduced, and the V-belt 10 wound around the V-shaped groove 9 is pushed outward in the radial direction.

Further, the driven pulley 21 is connected to the centrifugal clutch 17.
It is connected to the driven shaft 16 via. The centrifugal clutch 17 includes a clutch boss 18 that is engaged with the outer peripheral surface of the driven shaft 16 by a straight spline. A clutch housing 19 is welded to the clutch boss 18. The outer diameter of the clutch housing 19 is formed to be approximately the same as that of the driven pulley 21, and the clutch housing 19 is located outside of the driven pulley 21, that is, on the opposite side from the transmission case 5. Further, a driven side fixed pulley plate boss 20 is rotatably attached to the outer periphery of the clutch boss 18. This boss 20 has a fixed pulley plate 21a constituting the driven pulley 21.
and a retaining plate 22 are fixed. A centrifugal weight 23 is pivotally supported on the holding plate 22 by a pin 24, and a clutch lining 2 is attached to the centrifugal weight 23.
5 is attached.

Therefore, when the rotational speed of the retaining plate 22 reaches a certain value, the centrifugal weight 23 is displaced by centrifugal force, and the clutch lining 25 is pressed against the inner peripheral surface of the clutch housing 19. Due to friction, the clutch housing 19 is pressed against the retaining plate 2.
It is designed to rotate together with 2.

A movable pulley plate boss 26 is engaged with the outer peripheral surface of the fixed pulley plate boss 20 by a torsion spline 27. The movable pulley plate boss 26 has a movable pulley plate 21 paired with the fixed pulley plate 21a.
b is welded, and the V-belt 10 is welded between the movable pulley plate 21b and the fixed pulley plate 21a.
A V-shaped groove 29 on the driven side is formed around which the other end is wound.

The movable pulley plate 21b is urged toward the fixed pulley plate 21a by an elastic member 30 such as a coil spring, and the groove width of the V-shaped groove 29 is constantly reduced.

Further, a reduction gear 31 is mounted on the driven shaft 16, and this reduction gear 31 meshes with a reduction gear 33 provided on the intermediate shaft 32. A further reducing gear 34 is provided on the intermediate shaft 32, and this reducing gear 34 meshes with an increasing reducing gear 36 of the output shaft 35. A sprocket 37 is provided on the output shaft 35, and a chain 38 is wound between this sprocket 37 and a sprocket of a rear wheel shaft (not shown).

On the other hand, the crank case 1a and the transmission case 5
A case cover 40 is attached to the side opening. A case cover 40 covers the V-belt automatic transmission 6 and centrifugal clutch 17, and a kick-type starting device 41 is integrally attached to the case cover 40.

To explain this starter 41, a boss portion 40a is formed on the inner surface of the case cover 40 between the crankshaft 1 and the driven shaft 16, and the boss portion 40a is parallel to the crankshaft 1. A kick shaft 42 forming a shape is pivotally supported. Kick shaft 4
One end of the shaft 2 slightly protrudes into the space surrounded by the case cover 40 and the transmission case 5 without crossing the V-belt 10, and a fan-shaped helical gear 45 is attached to one end of the kick shaft 42. Welded. Further, the other end of the kick shaft 42 is led out to the outside of the case cover 40, and this lead-out end has a
A kick crank 43 with a kick pedal 44 is connected.

Furthermore, on the inner surface of the front end of the case cover 40,
A support shaft 46 is fixedly provided coaxially with the crankshaft 1 . The support shaft 46 is parallel to the lock shaft 42, and the case cover 40 of this support shaft 46
On the outer periphery that protrudes inward, there is a boss portion 48 of the speed increasing helical gear 47 that meshes with the helical gear 45.
It is pivotally supported to be slidable in the axial direction and rotatable in the direction around the axis.

Therefore, when the kick shaft 42 is rotated by depressing the kick pedal 44, the helical gear 45 is rotated, and the speed increasing helical gear 47 that meshes with this helical gear 45 is rotated at a constant speed. It is designed to be rotationally driven by the speed ratio.

Also, the boss portion 48 of this helical gear 47 for speed increase
A starting dog gear 49 is integrally connected to the starting dog gear 49. The starting dog gear 49 faces another dog gear 50 attached to the end of the crankshaft 1 so as to be able to come into and out of it, and this starting dog gear 49 has a larger diameter than the speed increasing helical gear 47, in other words. Then, the speed increasing helical gear 47 becomes the starting dog gear 4.
It is formed to have a smaller diameter than 9.

A return spring 51 is attached to the outer peripheral surface of the starting dog gear 49, and one end of the return spring 51 is locked to the case cover 40. When the speed-increasing helical gear 49 is rotated, the return spring 51 provides resistance to the rotation of the speed-increasing helical gear 49, and converts this rotational force into a force in the axial direction of the support shaft 46. This return spring 51
Due to the presence of
As shown in the lower half of the support shaft 46 in FIG.
9 jumps toward the dog gear 50, or as shown in the upper half of the support shaft 46 in FIG.
The starting dog gear 49 is designed to be detached from the dog gear 50.

Note that such a return spring 51 is necessary when the pair of helical gears 45 and 47 that mesh with each other are used to return the starting dog gear 49 in the direction of separating from the dog gear 50, or conversely to make it jump into the dog gear 50. It may have a similar structure to a well-known spring used in a conventional starting device.

Further, reference numeral 52 in the figure indicates another return spring that urges the helical gear 45 and the kick shaft 42 in the return direction.

According to such a configuration, since the kick shaft 42 is located between the crankshaft 1 and the driven shaft 16, the rotation of the kick shaft 42 when the crank crank 43 is stepped down is caused by a pair of shafts that mesh with each other. After the speed is increased by the helical gears 45 and 47, the speed is transmitted to the starting dog gear 49 which is integrated with the helical gear 47.

For this reason, the rotational force transmission path is simplified compared to the past, and there is no need to arrange two gears axially side by side on the shaft located in this transmission path, so the support is increased accordingly. The length of the shaft 46 and the stiff shaft 42 can be shortened, and the case cover 40 can be prevented from expanding laterally.

Moreover, since the kick shaft 42 and the support shaft 46 are both supported by the case cover 40, there is no need to provide a bearing part for each shaft 42, 46 in the transmission case 5, and the axial length of both shafts 42, 46 is Not only can the engine be shortened, but also the structure of the engine itself can be simplified.

At the same time, a centrifugal clutch 17 is located between the case cover 40 and the driven pulley 21, and the kick shaft 42 supported by the case cover 40 is located in front of the centrifugal clutch 17, avoiding the centrifugal clutch 17. Therefore, the lock shaft 42 and the centrifugal clutch 17 do not interfere with each other, and one end of the lock shaft 42 is placed closer to the case cover 4 than the outer surface of the clutch housing 19 of the centrifugal clutch 17.
It can be inserted toward the inside of 0. Therefore, by providing the case cover 40 with the boss portion 40a that protrudes inward, it is possible to ensure a sufficient bearing length for the screw shaft 42, and since the boss portion 40a protrudes inside the case cover 40, the screw shaft The bearing portion 42 can prevent the case cover 40 from protruding laterally.

Furthermore, according to this embodiment, at the time of hard starting,
Since the speed increasing helical gear 47 and the starting dog gear 49 slide in the axial direction on the support shaft 46,
The support shaft 46 can be made shorter than the case where the support shaft 46 is displaced together with the speed increasing helical gear 47 and the starting dog gear 49.

That is, when the support shaft 46 is configured to slide with respect to the case cover 40, the support shaft 4
In order to reliably support the case cover 6 without tilting, even when the support shaft 46 is displaced toward the crankshaft 1 side, a certain amount of fitting length of the support shaft 46 to the case cover 40 must be secured. Then, the axial length of the support shaft 46 becomes longer by the increased fitting length, so when the support shaft 46 is slid in the direction away from the crankshaft 1, the support shaft 46 becomes longer.
As a result, the end portion of the case cover 40 protrudes largely to the side of the case cover 40, and the case cover 40 has to be shaped so as to protrude largely to the side at this support shaft 46 portion.

On the other hand, in the above configuration, the speed increasing helical gear 47 and the starting dog gear 49 slide in the axial direction on the support shaft 46 fixed to the inner surface of the case cover 40, so the support shaft 46 and the case cover 40 can be reduced.
The axial length of the support shaft 46 can be shortened.

Therefore, it is not necessary to arrange two gears on this support shaft 46, and the case cover 40 can be prevented from protruding laterally at the bearing portion of the kick shaft 42. It can be formed into a compact shape with less tension, and the engine can be made smaller accordingly.

Furthermore, since the tight shaft 42 does not cross the V-belt 10, the tight shaft 42 does not cross the V-belt 10.
0 insertion position, drive pulley 7 and driven pulley 2
It can be placed without being restricted to one position, increasing the degree of freedom in placing the kick shaft 42.

For this reason, it is possible to bring the kick shaft 42 sufficiently close to the support shaft 46, and the diameters of the helical gears 45 and 47 that mesh with each other are made small, and the starting device 4
1 can be summarized in a compact manner.

In addition, in the case of the above configuration, the transmission line that increases the speed and transmits the rotation of the crankshaft 42 to the crankshaft 1 is all attached to the case cover 40 side, so it takes time and effort to attach and detach the case cover 40. In addition, by simply removing the case cover 40, the V-belt automatic transmission 6 and the starting device 41 can be separately separated and exposed.

For this reason, the V-belt automatic transmission 6 and the starting device 4
1. Maintenance and inspection work can be easily performed.

[Effects of the Invention] According to the present invention described in detail above, it is possible to simplify the transmission path that transmits the rotational force to the starting dog gear, and also to axially connect two gears on the shaft located in this transmission path. Since there is no need to arrange them side by side, the length of the support shaft and the kick shaft can be shortened accordingly, and the amount of lateral protrusion of the case cover can be suppressed.

Moreover, since the kick shaft supported by this case cover is located in front of the centrifugal clutch, avoiding the centrifugal clutch, there is no interference between the jack shaft and the centrifugal clutch. It can be inserted into the inside of the case cover rather than the outside surface of the case. For this reason, the bearing part of the locking shaft on the case cover side can also be extended inside the case cover, making it possible to secure a sufficient bearing length for this locking shaft. It is possible to prevent it from overhanging.

Therefore, in addition to not having to line up two gears on the support shaft, the case cover itself can be formed into a compact shape with less protrusion, which makes it possible to downsize the engine. Become.

Furthermore, since there is no need to provide bearings for the hard shaft and the support shaft in the transmission case, the lengths of both shafts can be shortened, and the structure of the engine itself can be simplified.

Furthermore, since the tight shaft does not cross the V-belt, the degree of freedom in arranging the tight shaft with the V-belt automatic transmission increases. Therefore, the kick shaft can be brought sufficiently close to the support shaft, the diameters of the helical gears that mesh with each other can be reduced, and the starter itself can be packed compactly.

In addition, in the case of the above configuration, since the starting device is all attached to the case cover side, there is no need to attach or remove the case cover, and the V-belt automatic transmission can be connected to the V-belt automatic transmission by simply removing the case cover. The starting device can be separated and exposed separately. Therefore, there is an advantage that maintenance and inspection of the V-belt automatic transmission and the starting device can be performed easily.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention. 1...Crankshaft, 1a...Crankcase,
5...Transmission case, 6...V-belt automatic transmission,
7... Drive pulley, 10... V belt, 21...
Driven pulley, 40... Case cover, 42... Hard shaft, 43... Hard crank, 45... Helical gear, 46... Support shaft, 47... Helical gear for speed increase, 49... Start Dog gear, 50... Dog gear.

Claims (1)

[Claims] 1. A driven shaft parallel to the crankshaft is provided at the rear end of the transmission case extending rearward from one side of the crankcase, and a driven pulley positioned on the driven shaft and the crankshaft are connected to each other. A V-belt automatic transmission is constructed by winding a V-belt between the driven pulley and the drive pulley, and the periphery of the V-belt automatic transmission is attached to the side openings of the crankcase and transmission case. In an engine covered with a case cover, a centrifugal clutch is provided on the driven shaft, located between the driven pulley and the case cover, for connecting and connecting the rotation of the driven pulley to the driven shaft; The case cover passes through the case cover between the centrifugal clutch and the crankshaft located in front of the centrifugal clutch, and has one end led out into a space surrounded by the case cover and the transmission case. A kick shaft to which a kick crank is connected to the other end led out to the outside of the cover, and a support shaft that is coaxial with the crank shaft and protrudes inside the case cover are provided, and on this support shaft, A starting dog gear that engages with the dog gear provided at the end of the crankshaft so that it can come into contact with and separate from it, and a speed increasing helical gear that rotates together with this starting dog gear are provided, and this speed increasing helical gear is connected to the case cover. A kick-type starting device for an engine, characterized in that the engine is constantly engaged with a helical gear provided at one end of the above-mentioned kick shaft on the inside of the engine.