JPH03175151A - Starting device of internal combustion engine - Google Patents

Abstract

PURPOSE:To provide damper function in response to reverse rotation of an engine by separating a driven starter gear from an axially fitted boss, forming a dog and a dog hole at the separated opposing faces, engaging it with a dog clutch, and providing the engaging face with a damper function in response to the reverse rotation of an engine through provision of a damper member thereat. CONSTITUTION:When a starter motor 14 is operated at the starting time, a driven starter gear 8a is deceleratedly driven widely via idle gears 16-18. Rota tion for strating is transmitted to a crank shaft 4 via a dog clutch 12 and a one-way clutch 9. The crank shaft 4 and the driven starter gear 8a are separated by the clutch 9 after the starting. A the starting time, when timing of ignition with piston action does not meet, the crank shaft 4 is apt to perform reverse rotation, impulsive reverse rotation torque is performed at this time via the one-way clutch 9. To the driven starter gear 8a, however, the reverse torque is transmitted via a damper rubber 13 provided at the dog clutch 12. Trouble is prevented without giving a strong shock to the idle gears 16-18 and the starter motor 14.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention relates to an internal combustion engine in which a driven starter gear is rotatably supported on a crankshaft, and starting torque is transmitted via a one-way clutch. Related to engine starting devices.

(Prior Art) For example, in a starting device for an engine mounted on a two-wheeled motor vehicle, as shown in FIG. It becomes the inner race of the combined one-way clutch,
The outer race d is fixed to the magnetrotor e and integrally connected to the crankshaft a.

By driving the starter motor, starting torque is applied to the driven starter gear b via the idle gear, thereby driving the crankshaft a via the one-way clutch. The rotation of crankshaft a after starting is
It is separated from the starting system by the action of the one-way clutch.

However, since the rotational speed is extremely low during startup, the ignition may occur too quickly and cause the crankshaft to rotate in reverse.

In this case, the one-way clutch acts to drive the driven starter gear and idle gear.

Reverse the starter motor. This reverse torque acts shockingly and often causes damage to each gear and the starter motor.

To prevent this, conventionally, the driven starter gear b is provided with a damper function. That is, as shown in Fig. 5, the tooth part f side and the boss part C side of the driven starter gear b are separated by a cylindrical surface, and both are connected by a pin g and an elongated hole so that they can be relatively displaced in the circumferential direction. In addition, a damper spring i is interposed between the two.

In this way, the impact of reverse rotation is alleviated by the buffering action of the damper spring i, but with this structure, the driven starter gear b is required to have a certain degree of thickness in order to stabilize its operation. Therefore, the crankshaft a becomes longer and longer, requiring reinforcement measures, and the engine width also increases, leading to an increase in weight.

(Problems to be Solved by the Invention) This invention attempts to solve the above-mentioned problems without increasing the width of the driven starter gear.
An object of the present invention is to provide a starting device for an internal combustion engine that is equipped with a damper function that supports engine reversal.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the internal combustion engine starting device of the present invention is of a roller wedge type in which the boss portion of the driven starter gear rotatably supported on the crankshaft is used as an inner race. In an internal combustion engine starting device that comprises a one-way clutch and connects its outer race to the crankshaft, only the starting torque given to the driven starter gear is transmitted to the crankshaft. It is separated from the boss, a dog and a dog hole are formed in the separated opposing surfaces, and engaged as a dog clutch, and a damper member is interposed on the engagement surface of the dog clutch.

(Function) With this configuration, the driven starter gear is driven by the starter motor via the idle gear,
The starting rotation is transmitted to the crankshaft through the dog clutch and one-way clutch. After starting, the crankshaft and driven starter gear are separated by a one-way clutch.

If the crankshaft rotates in the opposite direction due to a starting error,
The impact torque is transmitted to the driven starter gear via the one-way clutch, but is buffered by the intervening damper member, preventing damage to these parts without applying a strong impact to the driven starter gear, idle gear, or starter motor.

Since the damper member is incorporated into the boss portion of the driven starter gear, the width of the driven starter gear can be maintained at the minimum required dimension, and the length of the crankshaft and the engine width are not increased.

(Example) DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings showing embodiments of the present invention will be explained below.

Figures 1, 2, and 3 show a starting device for a motorcycle engine, in which a magneto cover 2 is attached to the side surface of a crankcase 1 to form a magneto chamber 3. A rotor 5 is fixed to the tip of a protruding crankshaft 4, and a stator 6 is attached to the back surface of the magneto cover 2, forming a magneto.

A boss portion 8b of a driven starter gear is rotatably supported on the crankshaft 4 behind the rotor 5 by a needle bearing 7. This boss portion 8b is processed as an inner race of a roller wedge type one-way clutch 9, and a roller 10 is interposed between it and the outer race 9a. The outer race 9a is fixed to the back surface of the rotor 5.

The boss portion 8b has a stepped portion 1 having a narrowed outer diameter on a part of the inner side.
1 is formed, and a driven starter gear 8a is rotatably supported on this stepped portion 11.

A dog clarifier 2 is installed on the opposing surface of the boss portion 8b and the driven starter gear 8a. That is,
A dog 12a is provided protrudingly on the driven starter gear 8a side, and engages with a circumferentially elongated dog hole 12b recessed on the boss portion 8b side. Additionally, a damper rubber 13 is inserted into the dog hole 12b.

Driven starter gear 8a is driven by starter motor 14 via drive starter gear 15 and idle gears 16, 17, 18 on its output shaft. These idle gears 16, 17, and 18 are located in the crankcase 1.
and the support shafts 16a, 17 straddled between the magneto cover 2 and the magneto cover 2.
a, and is pivotally supported by 18a.

When the starter motor 14 operates at the time of starting, the driven starter gear 8a is driven with a large deceleration through the idle gears 16, 17, 18, and the dog clutch 12. The starting rotation (arrow in FIG. 2) is transmitted to the crankshaft 4 through the one-way clutch 9. After starting, the one-way clutch 9 separates the crankshaft 4 from the driven starter gear 8a, the idle gears 16, 17, 18, and the starter motor 14.

When starting, if the timing of the ignition and piston movement do not match due to the advance angle, the crankshaft will rotate in the opposite direction (dotted arrow)
In that case, an impactful reverse torque is transmitted to the boss portion 8b via the one-way clutch 9.
The information is transmitted from the boss portion 8b to the driven starter gear 8a while being damped by a damper rubber 13 interposed in the dog clutch 12, and further transmitted to a series of idle gears 16, 17, 1.
8. No strong impact is applied to the starter motor 14, which prevents troubles such as damage.

In this way, this driven starter gear has a damper member built into the boss portion 8b, so the width of the driven starter gear can be maintained at the minimum necessary dimension, and the length of the crankshaft 4 and the engine width can be kept small. Do not increase.

〔Effect of the invention〕

As mentioned above, the internal combustion engine starting device according to the present invention includes:
A roller wedge type one-way clutch is constructed with the boss part of the driven starter gear rotatably supported on the crankshaft as an inner race, and by connecting the outer race to the crankshaft, starting torque is applied to the driven starter gear. A damper device is incorporated in the boss part of the driven starter gear to provide a damper function that supports engine reversal without increasing the width of the driven starter gear. This has the effect of keeping the crankshaft and engine width to the minimum necessary dimensions.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing a starting device according to an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional side view taken along arrow A-A in Fig. 1, and Fig. 3 is a cross-sectional view taken along arrow B-B in Fig. 2. 4 is a vertical sectional view showing a conventional starting device, and FIG. 5 is an enlarged vertical sectional side view taken along line D--D in FIG. 4. 4... Crankshaft, 5... Magnetrotor,
8a...Driven starter gear, 8b...Boss part,
9...One-way clutch, 9a...Outer race, 12...Dog clutch, 12a...Dog,
12b...dog hole, 13...damper rubber, 14.
...Starter motor, 16,17.18...Idle gear.

Claims (1)

[Claims] A roller wedge type one-way clutch is constructed with the boss part of the driven starter gear rotatably supported on the crankshaft as an inner race, and by connecting the outer race to the crankshaft, starting torque is applied to the driven starter gear. In the starting device for an internal combustion engine, the driven starter gear is separated from the shaft coupling boss, and a dog hole and a dog hole are respectively formed on the separated opposing surfaces, and the driven starter gear is engaged as a dog clutch. A starting device for an internal combustion engine, characterized in that a damper member is interposed on the engagement surface of the dog clutch.