JPS64592B2 - - Google Patents

Description

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

[Conventional technology]

A V-belt automatic transmission uses a V-belt to connect a drive pulley that is directly connected to the engine's crankshaft and a driven pulley on a driven shaft, and adjusts the diameter of the belt around the pulley depending on the rotational speed of the crankshaft. It is designed to automatically change the gear ratio by counting.

By the way, when incorporating a kick-type starting device into an engine equipped with this type of V-belt automatic transmission, conventionally, for example, the method disclosed in ``Patent Publication No. 53-58232''
As an example of this, a case cover covering a V-belt automatic transmission is provided with a kick shaft located coaxially with the crankshaft, and a starting dog gear is provided at the end of this kick shaft. Another dog gear is provided at the end of the crankshaft facing the starting dog gear, and when the crankshaft is rotated by stepping down, the starting dog gear jumps into engagement with the dog gear on the crankshaft side. The rotation of the crankshaft is transmitted to the crankshaft.

In this conventional starting device, in order to increase the rotation speed of the crankshaft and transmit it to the crankshaft, a first speed-increasing gear is spline-engaged on the crankshaft, and at the rear of the crankshaft, An intermediate shaft is provided that spans between the case cover and the crankcase, and a second speed-increasing gear that meshes with the first speed-increasing gear is mounted on the intermediate shaft, and the second speed-increasing gear rotates integrally with the second speed-increasing gear. third speed increasing gears arranged in the axial direction,
This third speed increasing gear is meshed with the circumferential surface of the starting dog gear. Therefore, when the kick crank is stepped down, 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.

[Problem to be Solved by the Invention] However, in the conventional configuration, the rotation of the kick shaft is transmitted once to the speed increasing gear on the rear intermediate shaft, and then again to the starting dog gear on the rear intermediate shaft. Because it is necessary to arrange the two speed-up gears side by side in the axial direction, the intermediate shaft must be made longer, which causes the case cover to protrude laterally, making the engine smaller and lighter. There is a problem that prevents it.

Moreover, since the intermediate shaft spans between the case cover and the crankcase, a bearing part for the intermediate shaft must be provided on the crankcase side, which complicates the structure and makes the intermediate shaft Since it is necessary to avoid belts, pulleys, etc., there are significant restrictions on the installation position of the intermediate shaft.

Additionally, if the intermediate shaft is also supported on the crankcase side, the intermediate shaft and crankcase must be precisely aligned, especially when installing the case cover, which requires more effort to attach and remove the case cover. Then there was a problem.

Therefore, the present invention has a simple structure, which makes it possible to reduce the size and weight of the engine, and also makes it possible to easily perform maintenance and inspection work on the V-belt automatic transmission and the entire device without requiring any effort to attach or remove the case cover. To provide a kick-type starting device for an engine which can be started easily and has an increased degree of freedom in the mounting position of a key shaft.

[Means to solve 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 the driven pulley provided on this driven shaft and the crankshaft A V-belt automatic transmission is constructed by winding a V-belt between the drive pulley and the V-belt.
The belt automatic transmission is assumed to be surrounded by a case cover attached to the side openings of the crankcase and transmission case, and the case cover is installed between the crankshaft and the driven shaft. A crankshaft to which the crankshaft is connected is provided, and a support shaft coaxial with the crankshaft is provided, and a starting mechanism is provided on the support shaft that engages removably with a dog gear provided at the end of the crankshaft. A helical gear for increasing speed is provided which rotates integrally with the dog gear for starting and this dog gear for starting, and this helical gear for increasing speed is constantly meshed with the helical gear provided on the above-mentioned kick shaft. There is.

[Effect]

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. The force transmission path is simplified, and there is no 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. be able to.

Moreover, since both the hard shaft and the support shaft are supported on the case cover side, this also contributes to shortening the shaft length, eliminates the need for special bearings on the transmission case or crankcase side, and improves the structure. can be simplified.

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, 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, so there is no need to put on or take off the case cover, and all you have to do is remove the case cover. The V-belt automatic transmission and starting device can be exposed, making maintenance and inspection work easier.

〔Example〕

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. That is,
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 a 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 7a is fixed to the crankshaft 1.
b is provided so as to be freely movable in the axial direction with respect to the crankshaft 1 and freely rotatable in the circumferential direction in order to vary the groove width of the V-shaped groove 9. A support plate 11 that rotates together with the crankshaft 1 is fixed to the back of the movable pulley plate 7b.
A centrifugal weight 12 made of balls, rollers, etc. is interposed between the movable pulley plate 7b and the movable pulley plate 7b. As the rotational speed of the crankshaft 1 increases, the centrifugal weight 12 is moved in the outer diameter direction by centrifugal force, and this movement presses and displaces the movable pulley plate 7b toward the fixed pulley plate 7a. V
The groove 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 clutch boss 18 of this centrifugal clutch 17 is connected to the driven shaft 16.
A clutch housing 19 is welded to the clutch boss 18 by a straight spline. Also, clutch boss 1
A driven side fixed pulley plate boss 20 is rotatably attached to the outer periphery of the driven side fixed pulley plate. A fixed pulley plate 21a and a holding plate 22, which constitute the driven pulley 21, are fixed to the boss 20. A centrifugal weight 23 is pivotally supported on the holding plate 22 by a pin 24.
A clutch lining 25 is attached to the centrifugal weight 23.

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 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 a kick-type starting device 41 is integrally attached to the case cover 40.

To explain this starting device 41, a boss portion 40a is formed on the inner surface of the case cover 40 and is located between the crankshaft 1 and the driven shaft 16. A parallel kick shaft 42 is pivotally supported. One end of the kick shaft 42 is led out, and a kick crank 4 equipped with a kick pedal 44 is attached to this lead-out end.
3 are connected. In addition, the other end of the locking shaft 42 does not cross the V-belt 10 and is connected to the case cover 4.
0, and a sector-shaped helical gear 45 is welded to the other end.

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
A boss portion 48 of a speed-increasing helical gear 47 that meshes with the helical gear 45 is pivotally supported on the inwardly protruding outer periphery so as to be slidable in the axial direction and rotatable in the axial direction. ing.

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 at a speed increasing 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. Due to the presence of this return spring 51, the speed increasing helical gear 47 is reciprocated along the axial direction of the support shaft 46, and as shown in the lower half of the support shaft 46 in FIG. The dog gear 49 jumps toward the dog gear 50, or the first
As shown in the upper half of the support shaft 46 in the figure, the starting dog gear 49 is detached from the dog gear 50.

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

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 crankshaft 42 is located between the crankshaft 1 and the driven shaft 16, the rotation of the crankshaft 42 when the crankshaft 43 is stepped down is caused by a pair of mutually meshing shafts. 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 lengths of the shaft 46 and the shaft 42 can be shortened, and the amount of lateral protrusion of the case cover 40 can be suppressed, allowing the engine to be made smaller and lighter.

Moreover, since the crank shaft 42 and the support shaft 46 are both supported by the case cover 40, there is no need to provide bearings for the shafts 42 and 46 in the crankcase 1a and the transmission case 5, and both shafts 46
Not only can the axial length of the engine 2, 46 be shortened, but also the structure of the engine itself can be simplified. At the same time, since the tightening shaft 42 does not cross the V-belt 10, the tightening shaft 42 can be placed without being influenced by the insertion position of the V-belt 10 or the positions of the driving pulley 7 and the driven pulley 21. The degree of freedom in the layout of this stiff shaft 42 is increased. Therefore, it is possible to bring the locking shaft 42 sufficiently close to the support shaft 46, so that the diameters of the helical gears 45 and 47 that mesh with each other can be reduced, and the shaft length can be shortened. The starter device 41 can be made smaller and lighter.

In addition, in the case of the above configuration, the transmission line that increases the speed and transmits the rotational force of the crankshaft 42 to the crankshaft 1 is
Since they are all attached to the case cover 40 side, it does not require any effort to attach or detach the case cover 40, and the V-belt automatic transmission 6 and starting device 41 can be exposed simply by removing the case cover 40. can. Therefore, maintenance and inspection work on the V-belt automatic transmission 6 and the starting device 41 can be easily performed.

〔Effect of the invention〕

According to the present invention described in detail above, it is possible to simplify the transmission line that transmits the rotational force to the starting dog gear, and it is not necessary to arrange two gears axially side by side on the shaft located in this transmission line. Therefore, the length of the support shaft and the kick shaft can be shortened accordingly, and the amount of sideward protrusion of the case cover can be suppressed, making it possible to make the engine smaller and lighter.

Moreover, since there is no need to provide bearings for the hard shaft or support shaft in the crankcase or transmission case, the length of both shafts can be shortened, and the structure of the engine can also be simplified. . Also, since the stiff shaft does not cross the V-belt, the degree of freedom in the layout of the stiff shaft is increased.
By bringing the kick shaft sufficiently close to the support shaft, the diameter of the helical gear can be reduced, and the starter device can be made more compact.

In addition, in the case of the above configuration, all the starting devices are attached only to the case cover side, so there is no need to attach or remove the case cover, and the V-belt automatic transmission or This has the advantage that the starting device can be exposed, making maintenance and inspection work easier.

[Brief explanation of the drawing]

The drawing 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 provided on this driven shaft and the crankshaft A V-belt automatic transmission is constructed by winding a V-belt between the driven drive pulley, and the V-belt automatic transmission is surrounded by a case attached to the side openings of the crankcase and transmission case. In the engine covered with a cover, the case cover is provided with a crankshaft located between the crankshaft and the driven shaft to which the crankshaft is connected, and a support shaft coaxial with the crankshaft. A starting dog gear is provided on the support shaft, and a starting dog gear that engages with a dog gear provided at the end of the crankshaft so as to be able to come into contact with and separate from the crankshaft, and a speed increasing helical gear that rotates together with this starting dog gear are provided. A kick-type starting device for an engine, characterized in that a speed helical gear is constantly meshed with a helical gear provided on the above-mentioned kick shaft.