JPH04159455A - Multidisk friction type torque limiter - Google Patents

Abstract

PURPOSE:To simplify a structure so as to attain smallness in size and lightness in weight by providing constitution such that gear teeth are provided in a peripheral part of a drive plate and meshed with a pinion gear of a starter motor to directly drive the drive plate. CONSTITUTION:In this multidisk friction type torque limiter 21, a plurality of driven plates 22 are meshed with a spline 10a in the periphery of a gear shaft 10 and also a drive plate 23 loosely fitted to the gear shaft 10 in a condition that the drive plate is held mutually between each of the driven plates 22. A facing material 23a is adhesively attached or welded to both surfaces of this drive plate 23, and a reduction gear wheel 23b is integrally formed in a peripheral part, to always mesh a plurality of the reduction gear wheels 23b in the periphery of the drive plate 23 as a set with a pinion gear 2a. A washer 24 is provided in both sides of the driven plate 22 and the drive plate 23, alternately piled together, and also arranging a belleville spring 25 in a side where a reduction pinion gear 4 is mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an engine starting device, and more particularly to a multi-plate friction torque limiter for preventing reverse load transmission to a starter motor.

(Prior Art) Conventionally, a constant-mesh type starter mechanism applied to an engine of a two-wheeled motor vehicle or the like is configured as shown in FIG. 2.

The driving force of the starter motor 1 is reduced by a pinion gear 2a formed on the 8-force shaft 2 of the starter motor 1, transmitted through a large reduction gear 3 and a small reduction gear 4 that rotates integrally with the large reduction gear 3, and further reduced to an idle gear 5. The starter gear 7 is driven through the engine to rotate the engine crankshaft 6 and start the engine.

The starter gear 7 is attached to the crankshaft 6 via a one-way clutch 8.
Rotation is transmitted only in the positive rotation direction (arrow +). In this engine starting device, the inner periphery of the large reduction gear 3 includes:
A torque limiter 9 is provided.

The torque limiter 9 prevents the crankshaft 6 from occasionally rotating strongly in reverse (
(in one direction of the arrow), it has the function of buffering the reverse rotational force and preventing damage to the starter motor 1 due to excessive reverse load.

Various types of torque limiters have been devised, but the multi-plate friction torque limiter shown at 9 in Figure 2 (see Japanese Patent Application Laid-open No. 187761/1983) operates most reliably and has the highest durability. Therefore, it is highly reliable.

A gear shaft 10 passes through the center of the torque limiter 9. The gear shaft 10 is provided with a spline 10a, and a plurality of driven plates 11 mesh with the spline 10a, and the driven plates 11 are mounted so as to rotate integrally with the gear shaft 10 and to be slidable in the axial direction. On the other hand, the housing 12 surrounding the gear shaft 10 is
A spline 12a is provided on the inner circumference, and this spline 1
A plurality of drive plates 13 are engaged with the housing 12, and the drive plates 13 are rotatably integrated with the housing 12 and are slidable in the axial direction.

The drive plate 13 has facing material 1 on both sides.
3a is glued or welded. The driven plate 11 and the drive plate 13 are assembled in a housing 12 so as to be alternately overlapped, washers 14 are attached to both sides thereof, and a bellows spring 15 is disposed after a small reduction gear 4, which will be described later, is attached. These driven plate 11, drive plate 13, washer 14, and flat spring 15 are arranged and held in the housing 12 by circlips 16 that fit into both ends of the inner circumference of the housing 12, thereby forming the torque limiter 9.

In FIG. 2, a thread 10b is cut on the gear shaft 10 on the right side of the torque limiter 9, and the small reduction gear 4 is screwed thereto. The small reduction gear 4 presses the counter spring 15 in the torque limiter 9 described above, and therefore a set surface pressure is applied between the driven plates 11 and the drive plates 13 that are stacked alternately in the torque limiter 9, and the driven Plate 11 and drive plate 13 are frictionally engaged.

A large reduction gear 3 is integrally formed on the outer periphery of the housing 12 and constantly meshes with a pinion gear 2a of the starter motor l.

With the above configuration, the torque limiter 9 prevents the frictional engagement between the driven plate 11 and the drive plate 13 in the torque limiter 9 from slipping when an excessive reverse load is applied to the gear shaft 10 when kick pack occurs during engine startup. , prevents the gear shaft 10 from idling and transmitting a reverse load to the starter motor l. This action protects the starter motor 1 from reverse loads.

(Problems to be Solved by the Invention) As described above, the multi-plate friction torque limiter is effective in preventing reverse loads from being transmitted to the starter motor, but due to its structure, it is large in both width and diameter. It was difficult to install it inside the narrow gear case of a small engine such as a motorcycle.

Furthermore, since the number of parts is large due to the structure, the cost tends to be high.

This invention was made in consideration of the above-mentioned problems.
The purpose of the present invention is to provide a multi-plate friction torque limiter that is small and low cost while having performance equivalent to conventional multi-plate friction torque limiters.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the multi-plate friction torque limiter of the present invention is provided in the middle of a starter mechanism that transmits the power of a starter motor for starting an engine to a crankshaft. In a multi-plate friction torque limiter for protecting a starter motor, gear teeth are provided on the outer periphery of the drive plate, and the gear teeth mesh with the pinion gear of the starter motor to directly drive the drive plate.

(Function) Since the multi-plate friction torque limiter of the present invention directly drives the drive plate with the starter motor, there is no need for a housing for holding the drive plate and for transmitting driving force, which was previously required. can be made smaller.

In addition, the number of parts is reduced, which leads to cost reduction.

(Example) An example of the multi-plate friction torque limiter according to the present invention will be described below.

Although the present invention can be applied to starter mechanisms for all types of engines such as reciprocating piston type engines, an example will be shown here in which it is applied to a starter mechanism for a small engine for a two-wheeled motor vehicle shown in FIG.

In Fig. 1, the torque limiter 21 and the large reduction gear 2
Components other than 3b are the same as those of the prior art motorcycle engine starter mechanism shown in FIG. 2, so the same reference numerals are given and the explanation thereof will be omitted.

A gear shaft 10 passes through a multi-plate friction torque limiter 21 shown in FIG. The inner peripheral portions of a plurality of driven plates 22 are engaged with the spline 10a surrounding the gear shaft 10, and the driven plates 22 are mounted to rotate integrally with the gear shaft 10 and to be slidable in the axial direction. Drive plates 23, the number of which is one less than the number of driven plates 22, are sandwiched between each of the plurality of driven plates 22. Each drive plate 23
is loosely fitted onto the gear shaft 10 and is provided so as to be freely rotatable or slidable around the gear shaft 10. Facing materials 23a are adhered or welded to both surfaces of the drive plate 23. The outer diameter of the drive plate 23 is larger than the driven plate 22, and large reduction gears 23b are integrally formed on each outer peripheral portion of the drive plate 23, and the large reduction gears 23b surrounding the plurality of drive plates 23 form one set. This results in constant meshing with the pinion gear 2a.

Washers 24 are attached to both sides of the driven plates 22 and drive plates 23, which are stacked alternately, and a flat spring 2 is attached to the side to which the small reduction gear 4, which will be described later, is attached.
5 is placed. The torque limiter 21 is composed of the above-mentioned parts.

The small reduction gear 4 adjacent to the torque limiter 21 is screwed to the external thread 10b on the gear shaft 10. The small reduction gear 4 presses the bellows spring 25 of the torque limiter 21, and therefore there is a surface pressure set by the reaction force of the bellows spring 25 between the driven plate 22 and the drive plate 23, which overlap within the torque limiter 21. is added, driven plate 22 and drive plate 23
are frictionally engaged.

In the constant mesh starter mechanism of a motorcycle equipped with this multi-plate friction torque limiter 21, if an excessive reverse load is applied to the gear shaft 10 when kick pack occurs during engine startup, the torque limiter 21 The frictional engagement between the driven plate 22 and the drive plate 23 prevents the gear shaft 10 from idling and transmitting a reverse load to the starter motor 1. This clutch action protects the starter motor 1 from reverse loads.

The multi-plate friction torque limiter for starters according to the present invention includes:
The structure described above eliminates the need for a housing (second
12) in the figure can be omitted, and the structure can be simplified.

〔Effect of the invention〕

As described above, the multi-plate friction torque limiter according to the present invention has gear teeth provided on the outer periphery of the drive plate, and the gear teeth mesh with the pinion gear of the starter motor to directly drive the drive plate. The structure is simpler, contributing to smaller size and lighter weight. Additionally, manufacturing costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of a starter mechanism for a motorcycle engine equipped with a multi-plate friction torque limiter according to the present invention, and FIG. FIG. 2 is a plan view showing a starter mechanism of an engine of a two-wheeled motor vehicle. 1... Starter motor, 2a... Pinion gear, 3
．． 23b...Reduction large gear, 6...Crankshaft, 9.21...Torque limiter, 12.23...Drive plate.

Claims (1)

[Claims] In a multi-plate friction torque limiter for protecting the starter motor, which is installed in the middle of the starter mechanism that transmits the driving force of the starter motor for starting the engine to the crankshaft, gear teeth are provided on the outer periphery of the drive plate. A multi-plate friction torque limiter that is designed to directly drive a drive plate by meshing with a pinion gear of a starter motor.