JPH0238106Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a centrifugal shoe-type starting clutch for a two-wheeled motor vehicle that is mounted on the crankshaft.

Some motorcycles are equipped with a centrifugal starting clutch that increases the transmitted torque in relation to the engine speed, but a one-way clutch is installed in parallel to transmit reverse torque at low speeds. A conventional starting clutch using a centrifugal shoe is shown in FIG.

A primary drive gear 2 is rotatably supported on a crankshaft 1, and a starting clutch is mounted on the crankshaft 1 adjacent to the primary drive gear 2. That is, the drive plate 5 of the centrifugal shoe 4 is pivotally supported by the spline 3 of the crankshaft 1 so as to rotate integrally therewith, and the inner 7 of the one-way clutch 6 is connected by the dog 8. A driven drum 9 facing the outer periphery of the centrifugal shoe 4 is fixed to the primary drive gear 2. Further, the one-way clutch outer 10 is integrally extended from the primary drive gear 2.

When the rotational speed of the crankshaft 1 increases, the centrifugal shoe 4 on the drive plate 5 that rotates integrally comes into contact with the driven drum 9, and as the centrifugal force increases, the transmitted torque is gradually increased to rotate the primary drive gear 2. When the starting clutch is not acting, reverse torque such as engine braking is transmitted from the primary drive gear 2 to the crankshaft 1 via the one-way clutch 6.

As shown in FIG. 2, when the outer 10 is rotated in the direction of the arrow with respect to the inner 7, the roller 11 wedges into the ratchet portion 12 of the outer 10, connecting the two, and the one-way clutch 6 rotates in the opposite direction. Displacement is unconstrained. A plurality of rollers 11 and ratchet portions 12 are provided. In such a one-way clutch 6, a lock with the inner 7 may occur due to a dimensional error in the latch portion 12. To prevent this, the outer 10 is given a degree of freedom within the error range, and all rollers 11 operate simultaneously during one-way operation. It can be so. In the above configuration, this problem is solved by setting a large gap between the inner diameter of the shaft hole of the primary drive gear 2.

However, when one of the starting clutches is activated, the driven drum 9 may be damaged due to the unbalance of the centrifugal force of the centrifugal shoe 4 or the jagging of the lining surface.
The primary drive gear 2, which is integrated with the primary drive gear 2, will fall down significantly if the gap is made large as described above, which will have an adverse effect on the tooth surface and cause gear noise.

Taking the above points into consideration, the purpose of this invention was to improve the alignment accuracy of the primary drive gear to the crankshaft to prevent it from falling over, and to absorb the eccentricity of the one-way clutch outer at another location, so that the one-way clutch To provide a starting clutch for a two-wheeled motor vehicle which prevents both primary drive gear locking and primary drive gear noise.

FIG. 3 shows an embodiment of the starting clutch of this invention. Starting clutch, one-way clutch 6, etc.
Components with the same functions as those in FIG. 1 are given the same reference numerals and their explanations will be omitted.

The primary drive gear 2 and the one-way clutch outer 10 are not integrated, but separated. And a stepped portion 1 is provided at the outer end of the primary drive gear 2.
3, the small diameter portion 14 has a tooth height reduced to about half.
The inner end of the one-way clutch outer 10 is provided with a female tooth profile 15 that fits loosely with the tooth profile of the small diameter portion 14.
and fit together. A disc spring 16 that presses inward is brought into elastic contact with the female tooth profile 15, and the inner end is brought into pressure contact with the stepped portion 13 to regulate the position in the axial direction. The primary drive gear 2 is slidably fitted onto the crankshaft 1 without any gap.

With the above configuration, the rotation of the driven drum 9 at the time of actuation of the starting clutch is controlled by the female tooth profile 15.
This is transmitted to the primary drive gear 2 through the engagement of the small diameter portion 14 with the teeth (hereinafter referred to as the engaging portion A). At this time, even if the driven drum 9 is tilted due to unbalance of the centrifugal force or due to the juddering of the centrifugal shoe 4, it is absorbed by the engaging portion A and the primary drive gear 2 does not tilt, maintaining high precision and gearing. No sound is generated. On the other hand, even when the one-way clutch 6 operates to transmit reverse torque, the outer 10 has a degree of freedom due to the engaging portion A, so the eccentricity is corrected and all the rollers 11 are engaged and locked. There is no.

As described above, the starting clutch for a two-wheeled motor vehicle according to this invention has a one-way clutch installed in parallel between the primary drive gear rotatably supported on the crankshaft and the crankshaft. The driven drum of the starting clutch and the one-way clutch outer are integrally connected, and this is engaged with one end of the primary drive gear with a female tooth profile, so that the primary drive gear can be precisely aligned with the crankshaft. The driven drum and one-way clutch outer are given a degree of freedom even when the starting clutch is activated, and the inclination of the driven drum when the starting clutch is activated and the eccentricity of the outer when the one-way clutch is activated are absorbed, thereby preventing gear noise and locking of the one-way clutch. Can be done. It has a simple structure that uses the teeth of the primary drive gear without adding any special parts, and has the effect of cleverly improving the function of a starting clutch installed in parallel with a one-way clutch.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of a conventional starting clutch, FIG. 2 is a longitudinal sectional front view showing the structure of a one-way clutch, and FIG. 3 is a longitudinal sectional side view showing an embodiment of the starting clutch of this invention. 1... Crankshaft, 2... Primary drive gear, 4... Centrifugal shoe, 6... One-way clutch, 9... Driven drum, 10... One-way clutch outer, 15... Female tooth profile.

Claims (1)

[Scope of utility model registration request] A primary drive gear is rotatably supported on the crankshaft, and a starting clutch is constituted by a clutch housing coupled to the primary drive gear and a centrifugal shoe on a drive plate fixed to the crankshaft. The clutch incorporates a one-way clutch in which a roller is held between an outer connected to the clutch housing and an inner connected to the drive plate, and the rollers are wedged together by the overdrive of the outer. In a starting clutch for a two-wheeled motor vehicle, a small-diameter stepped portion is formed at the outer end of the primary drive gear by removing about half the height of the teeth, while the inner end of the one-way clutch outer connected to the clutch housing is formed at the outer end of the primary drive gear. 1. A starting clutch for a two-wheeled motor vehicle, characterized in that a female tooth profile is formed on the female tooth profile, and the small diameter step part is fitted into the female tooth profile to integrate a primary drive gear and a clutch housing.