JPS5823500B2 - Starting device for engines with automatic two-speed transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting device for an engine equipped with an automatic two-speed transmission used in small motorcycles and the like.

In general, this type of two-speed automatic transmission has a low-speed transmission gear section and a high-speed transmission gear section, and when the rotational speed of the driven shaft exceeds a value, it changes from the low speed side (1st speed) to the high speed side (2nd speed). ) is configured to automatically switch to

However, when the gear is automatically shifted from 1st gear to 2nd gear, the interlocking gear part on the 1st gear side must be free, so the gear unit on the 1st gear side has a one-way joint. is provided.

On the other hand, in order to prevent the rotation of the starting gear from being transmitted to the driven shaft when starting the engine, a clutch, etc. for starting is installed in addition to the one-way joint to free the interlocking gear on the 1st speed side. It is necessary to provide

Therefore, such a transmission has problems such as a complicated mechanism and a large size.

In view of these points, the present invention combines the one-way joint on the first speed side and the clutch mechanism on the starting mechanism side into one, so that the configuration of this part can be simplified and the entire device can be miniaturized. An object of the present invention is to provide a starting device for an engine equipped with an automatic two-speed transmission.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 is the crankshaft of the engine, and one end of the crankshaft 1 has a low-speed centrifugal clutch 2.
is installed, and the driven body 3 of the low-speed centrifugal clutch 2
A low pinion 4 and a high pinion 5 are fixed to the.

A one-way joint 6 is interposed between the crankshaft 1 and the moving body 3, and the rotation is transmitted only from the driven body 3 to the crankshaft 1.

On the other hand, a low gear 7 and a high gear 8 are mounted on the driven shaft 9, and the low pinion 4 is connected to the low gear 7.
Further, high pinions 5 are meshed with high gears 8, respectively.

The driven shaft 9 has a starting gear 10 as shown in FIG.
A low gear 7 is rotatably supported on a spline 12 formed on a boss concentrically protruding from one side of the starting gear 10 so as to have play 11 in the rotational direction.
are fitted.

A threaded spline 14 is fixed to one side of the low gear T, and the threaded spline 14 is connected to the starting gear 10.
A sliding dog 13 is fitted into the spline 12 of.

The sliding dog 13 is opposed to a fixed dog 15 fixed to the driven shaft 9, and a brake piece 16 provided on the fixed dog 15 is in elastic contact with the inner circumference of the sliding dog 13.

On the other hand, the big gear 8 is rotatably supported by a driven shaft 9 and connected to the driven shaft 9 via a high-speed centrifugal clutch 17.

Further, the driven shaft 9 is connected to a deceleration pinion 18 and a gear 19.
On the other hand, the starting gear 10 is connected to a kick gear 22 via an idler 21, and the kick gear 22 is connected to a kick shaft 24 via a one-way joint 23.

As the rotation of the crankshaft 1 increases, the low-speed centrifugal clutch 2 is connected and the rotation is transmitted from the low pinion 4 to the low gear 7.

Therefore, the sliding dog 1 by the threaded spline 14
3 is pushed out and engages the fixed dog 15, and the low gear 7
rotation is transmitted to the driven shaft 9.

When the rotation increases further and reaches a certain number of rotations, the high-speed centrifugal clutch 17 is connected, and the power is transmitted from the bi-pinion 5 to the bi-gear 8, and then to the driven shaft 9 via the high-speed centrifugal clutch 17, resulting in high-speed operation. Become.

At this time, the low gear 7 rotates lower than the driven shaft 9, so the sliding dog 13 is retracted by the threaded spline 14 and disengaged from the fixed dog 15, causing the low gear 7 to rotate lower than the driven shaft 9.
becomes free.

On the other hand, when starting the crankshaft 1, when the kick shaft 2 is turned, the one-way joint 23, the kick gear 22, and the idler 2
1, and the starting gear 10 rotates.

When the starting gear 10 rotates, rotation is transmitted to the low gear 7, but while the spline 12 rotates between the play 11 between the spline 12 and the low gear 7, the sliding dog 13 fitted to the spline 12 is retracted and disengages from the fixed dog 15, so no rotation is transmitted to the driven shaft 9, and only the low gear 7 is rotationally driven.

Therefore, rotation is transmitted from the low gear 7 to the low pinion 4 and the one-way joint 6, driving the crankshaft 1 and starting the engine.

Note that when the low gear 7 is turned from the crankshaft 1 side, the starting gear 10, idler 21, kick gear 22
The kick shaft 24 also rotates, but the rotation transmission is cut off by the one-way joint 23 and the kick shaft 24 remains stationary.

As explained above, the present invention provides a low-speed centrifugal clutch on the crankshaft, and a low pinion and a bi-pinion fixed to the driven body of the low-speed centrifugal clutch are mounted on the crankshaft via a one-way joint. , a low gear that meshes with the low pinion is attached to the driven shaft, and a bi-gear that meshes with the bi-pinion and is mounted on the driven shaft is connected to the driven shaft via a high-speed centrifugal clutch. A starting gear is rotatably supported on the shaft, and the low gear is spline-fitted to the starting gear with play in the rotational direction, and the low gear is further fitted with a threaded spline and faces a fixed dog fixed to the driven shaft. Since the screwed sliding dog is spline-fitted, the joint made up of the threaded spline, sliding dog, and fixed dog allows the low gear to be freed during high-speed operation, and also to free the starting gear when starting the engine. It is also possible to perform a power transmission disconnection action on the driven shaft, there is no need to provide a separate clutch mechanism in the starting system, and the engine can be started via the low gear, requiring only a small number of gears. It can be simplified, and the entire device can be downsized.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which FIG. 1 is a schematic longitudinal sectional view of the entire structure, FIG. 2 is a longitudinal sectional view of a main part, and FIG. 3 is a cross sectional view taken along the line A--A in FIG. 7...Low gear, 9...Driven shaft, 10
...Starting gear, 11...Play, 12.
...Spline, 13...Sliding dog,
14...Screw spline, 15...Fixed dog.

Claims (1)

[Claims] 1 A low-speed centrifugal clutch is provided on the crankshaft, a low pinion and a high pinion fixed to the driven body of the low-speed centrifugal clutch are mounted on the crankshaft via a one-way joint, and a low gear meshed with the low pinion. In an engine starting device equipped with an automatic two-speed transmission, which is attached to a driven shaft and further meshes with the high pinion and connects a high gear mounted on the driven shaft to the driven shaft via a high-speed centrifugal clutch, A starting gear is rotatably supported on a driven shaft, and the low gear is spline-fitted to the starting gear with play in the rotational direction, and the low gear is further fitted with a threaded spline and fixed to the driven shaft. A starting device for an engine equipped with an automatic two-speed transmission, characterized in that a sliding dog facing the dog is spline-fitted.