JPH0625670Y2 - Internal combustion engine auto starter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention particularly relates to an autostarter for a relatively small internal combustion engine used in a brush cutter, a spreader or the like.

[Conventional technology]

A starter motor is usually used for the autostarter of the internal combustion engine as described above, the starting force is applied to the internal combustion engine by the starter motor, and the starter motor is stopped after the start. Therefore, a unidirectional power transmission device is provided between the starting electric motor and the crankshaft of the internal combustion engine, in which the power from the starting electric motor is transmitted, and the transmission of the power is canceled after the starting.

Conventionally, a one-way clutch in which a clutch needle roller is provided on an outer ring having a cam surface is used in the power transmission device.

[Problems to be solved by the device]

As described above, after the internal combustion engine is started, that is, when the crankshaft rotates, the driven gear is released from the crankshaft for driving and is supported by the bearing, and is in the loose fitting state.

However, due to run-out of the crankshaft during operation of the internal combustion engine, local contact phenomenon and uneven wear occur between the crankshaft and the bearing, and durability is impaired. The phenomenon may occur.

In order to solve the above problem, it is possible to use a rolling bearing, but there is a disadvantage that the cost is about three times as high as that in the case of using a sliding bearing.

Then, this invention aims at solving the said subject using an inexpensive plain bearing.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention is configured so that, even when the crankshaft is shaken, a local contact phenomenon and uneven wear are not generated between the bearing and the driven gear, and a co-rotation phenomenon is not generated. It is a thing.

That is, according to the present invention, the driven gear is mounted on the crankshaft through the needle roller forming the one-way clutch in the central boss portion and the slide bearings provided on both the outer side and the inner side in the axial direction of the crankshaft. The gap between the bearing on the outer side in the axial direction and the crankshaft is larger than the gap between the bearing on the inner side and the crankshaft.

[Action]

In the auto starter configured as described above, the starting electric motor is driven when the internal combustion engine is started, and the crank shaft is rotated via the drive gear, the intermediate gear, the driven gear and the needle roller. Then, after the internal combustion engine is started, the crankshaft rotates at a higher speed than the driven gear side, the one-way clutch needle roller is released from the crankshaft, and the driven gear is loosely fitted to the crankshaft.

When the crankshaft is rotated, the runout phenomenon of the crankshaft is greatest in the axially outer end direction of the crankshaft, that is, the outer side of the one-way clutch.

However, in the present invention, the gap between the bearing on the outer side in the axial direction of the crankshaft and the crankshaft is configured to be larger than the gap between the bearing on the inner side and the crankshaft. Also in this case, the phenomenon of local contact and uneven wear do not occur, and further, the co-rotation phenomenon of the driven gear caused by the increase of the friction coefficient therebetween can be prevented.

The sliding bearing is less expensive than the rolling bearing, and improves the durability of the one-way clutch by increasing the retention of the grease enclosed in the one-way clutch. Also, if the plain bearing is made of porous sintered alloy and impregnated with oil, self-lubrication is improved,
The friction coefficient can be reduced.

〔Example〕

An embodiment of the present invention will be described below in detail with reference to the drawings.

In the drawings, cylinders, pistons, connecting parts, etc. of the internal combustion engine are omitted, and only relevant parts of the present invention are shown.

In the figure, (1) is a crankshaft, and (2) is a crankcase.

The crankshaft (1) is rotatably supported in the crankcase (2).

In the present invention, the driven gear (6) has a needle roller (3) forming a one-way clutch in its central boss portion (6a) and plain bearings (4) provided on both the outer side and the inner side in the axial direction.
(5) is fitted to the crankshaft (1), and the one-way clutch is constituted by the central boss portion (6a) of the driven gear (6) including the needle roller (3) and the crankshaft (1). Has been done.

The driven gear (6) is a starting motor (7) when the internal combustion engine is started.
Driven by the drive gear (8) and the intermediate gear (9) to reduce the speed, and the needle roller (3) causes the crankshaft to move.
This is to rotate (1).

In the above structure, the present invention is arranged such that the outside of the needle roller (3) is more than the fitting gap between the crank shaft (1) and the bearing (4) on the inner side in the axial direction of the crank shaft (1). The gap (S) between the bearing (5) on the side and the crankshaft (1) is large.

This is because the runout phenomenon of the crankshaft (1) is due to the crankshaft (1).
This is because it is larger in the direction of the outer end of the needle roller (3), that is, outside the needle roller (3).

In order to have the above-mentioned structure, in the embodiment shown in the drawings, the outer bearing
By forming the crankshaft (1) of the portion (5) to have a smaller diameter than other portions and forming the small diameter portion (1a), a gap (S) larger than the inner side is formed.

The inner diameter of the outer bearing (5) may be machined larger than the inner diameter of the inner bearing (4) without changing the diameter of the crankshaft (1).

By the way, the size of the gap (S) depends on the crankshaft.
When the diameter (D) of (1) is 10 ^-0.006 mm, the bearing
The fitting gap between (4) and the crankshaft (1) is 50 to 76 μm.
The size is preferably about 150 to 176 μm.

In the figure, (10) is a spring provided between the driven gear (6) and an axial position regulating member (11) of the driven gear (6) provided on the crankshaft (1), and The outward movement of the driven gear (6) in the axial direction of the crankshaft (1) is restricted, and the collision noise between the roller (3) and the crankshaft (1) due to the roller play of the one-way clutch is reduced. The one-way clutch is provided to prevent damage to the one-way clutch due to repeated collisions, and further, when the internal combustion engine is started or stopped, the driven gear (6) overruns and the crankshaft (1) rotates together. Can be prevented.

In the figure, (12) is the magnet rotor, (13) is the crankcase (2)
The generator coil is fixed to the side fixing member, and charges a battery for a starter motor (not shown) during operation of the internal combustion engine.

According to the present invention having the above-mentioned structure, even when the crankshaft (1) is shaken during the rotation of the crankshaft (1), the outer bearing (5) having a large shake is Since the gap (S) is larger than that of the bearing (4), the crankshaft
Since the phenomenon of local contact and uneven wear do not occur between (1) and the bearing (5) and the friction coefficient between them does not increase, the co-rotation phenomenon of the driven gear is also prevented. .

[Effect of the present invention]

According to the present invention, even when the crankshaft is shaken during engine operation, the phenomenon of local contact and uneven wear do not occur between the crankshaft and the bearings. It is also possible to prevent a turning phenomenon.

Therefore, it is possible to improve the durability of the one-way clutch portion and to provide it at low cost by using the slide bearing.

[Brief description of drawings]

The drawing shows an embodiment of the present invention and is a longitudinal cross-sectional view of the main part thereof. (1) …… Crankshaft, (3) …… Needle roller, (4) (5)…
… Sliding bearing, (6) …… Driven gear, (S) …… Gap.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hirofumi Yamami 7-5-1, Shimorenjaku, Mitaka City, Tokyo Kyoritsu Co., Ltd. (72) Inventor Yokocho Yoetsu 7-5-1, Shimorenjaku, Mitaka City, Tokyo Stocks Company Kyoritsuuchi (72) Inventor Isao Masuda 7-5-1, Shimorenjaku, Mitaka City, Tokyo Kyoritsuuchi Co., Ltd. (56) Reference JP-A-54-151755 (JP, A) Mitsuihei 2-26766 (JP, U) Actually opened 63-193766 (JP, U) Actually opened 63-177666 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A needle roller (3) having a driven gear (6) constituting a one-way clutch in a central boss portion (6a) thereof, and sliding bearings (4) provided on both axially outer and inner sides thereof,
Is fitted to the crankshaft (1) via (5),
A gap (S) between the crankshaft (1) and the bearing (5) on the outer side in the axial direction of (1) is a gap between the bearing (4) and the crankshaft (1) on the inner side. An auto-starter for an internal combustion engine, which is configured to be larger.