JPS5854289B2 - Clutch with over-center mechanism - Google Patents

Description

[Detailed Description of the Invention] In a clutch that generates clutch connection load by an overcenter mechanism (or toggle mechanism), the overcenter mechanism generates the maximum load only within a narrow stroke range due to its nature. Therefore, it is necessary to accurately position the discs, friction plates, etc. so that the clutch is fully connected when the maximum load is generated.

Furthermore, the clutch connection load and its reaction force obtained by the overcenter mechanism must be absorbed by the clutch shaft without affecting (thrust) other parts of the clutch shaft as much as possible.

When a thrust load is applied, problems such as drag and wear occur.

The present invention aims to meet the above requirements and to prevent thrust loads from being applied, and will be described below with reference to the drawings.

In FIG. 1, a clutch shaft 1 is supported by a clutch case (not shown) via a bearing 2, and normally rotates in one direction when power is introduced from the right end, for example.

A bub 4 is fitted into a spline 3 provided on the shaft 1, and a plurality of annular driven plates 5 are slidably fitted into splines 5' on the outer periphery of the bub.

6 is a back plate, 7 is a spacer ring, 8 is two disc springs, and 9 is a snap ring.

・Clutch shaft 1 to regulate the amount of leftward movement of clutch 4
A snap ring 10 is fitted into an annular groove provided in the ring.

Instead of the snap ring 100, an annular projection may be integrally provided on the shaft 1.

A power take-off gear 13 supported on the clutch shaft 1 via a bearing 12 has a cylindrical housing 14 with a bottom.
The projections on the outer periphery of annular disks 16 fit into slits 15 provided in the cylindrical portion of the housing 14, and the disks 16 are arranged alternately between adjacent driven plates 50.

A pressure plate 17 is fitted to the spline 3, and is normally subjected to a rightward elasticity away from the disk group by a return spring 18 compressed between the pressure plate and the bubble 4.

A snap ring 19 attached to the clutch shaft 1 regulates the amount of rightward movement of the pressure plate 17.

A holder nut 22 of an overcenter mechanism is screwed into a male threaded portion 21 of the clutch shaft 1, and a cylindrical adapter 24 is fitted into a spline 23 on the clutch shaft 1.

Both the nut 22 and the adapter 24 are provided with a pair of protrusions 25, 26 at three equally spaced locations on their outer circumferences, and the pair of protrusions 25 are provided in the circumferential direction (relative to the clutch shaft 1) when viewed from the clutch shaft 1. Pin 27 (right angle) is fixed, and pin 2
Two rectangular plate-shaped cams 28 are rotatably supported on each of the cams 7 and 7.

The roller 3 is inserted between the two cams 28 via pins 29 and 30.
1 and link 32 are installed, and the right end of link 32 is 2.
It is connected to the protrusions 26 via pins 33 between the protrusions 26.

The pins 27, 29, and 30 each occupy the position of each vertex of a triangle, and in the clutch engaged state shown in the upper half of FIG. With respect to the line A, the center of the pin 29 occupies a position slightly outward (radially outward), and the stopper surface 34 at the left end of the adapter 24 abuts against the nut 22.

The adapter 24 has a thrust bearing 36 on its outer periphery.
A shift fork (not shown) is engaged with two pins 38 (FIG. 3) that protrude radially outward from the outer periphery of the sleeve 37, so that the shift fork (not shown) can be operated manually or by pedal operation. The sleeve 37 can be shifted in the direction of arrow B or C.

39-41 are thrust washers, and 43-46 are snap rings.

For convenience, the upper and lower halves of FIG. 1 show the engaged and released states of the clutch.

That is, when the sleeve 37 located in the lower half of FIG. The signal is transmitted to the cam 28 via the cam 28, and the cam 28 rotates about the pin 27 in the direction indicated by the arrow.

On the way, the roller 31 moves in the direction of the arrow on an arc centered on the pin 27, and when the center of the roller 31 is on the line A (center position), the roller 31 is most extended toward the pressure plate 17, When the surface 34 of the adapter 24 abuts against the nut 22, the center of the roller 31 moves radially outward by l from the line A (overcenter state) and stops at that position.

On the other hand, since the hub 4 is prevented from moving by the snap ring 10 on the clutch shaft 1, it remains stationary on the clutch shaft 1, and therefore the driven plate 5 and the disc 1
6 is tightened between a pressure plate 170 and a back plate 6 supported by a snap ring 9 which does not substantially move in the axial direction via a disc spring 8 and a spacer ring 7.

In this way, the rotational force is transferred from the clutch shaft 1 to the spline 3.
, the hub 4, the driven plate 5, the disk 16, and the housing 14, the signal is transmitted to the gear 13, and taken out from there.

Of course, power can also be transmitted through the reverse route.

To disengage the clutch, move the sleeve 37 in the direction of arrow C.

Then, the cam 28 rotates in the opposite direction about the pin 27, and the roller 31 moves radially inward after its center once passes over the line A, releasing the pressure plate 17.

The pressure plate 17 is caught in the elasticity of the return spring 18 and leaves the disk group while being in contact with the roller 31.

As explained above, according to the present invention, the leftward movement of the hub 4 is directly regulated by the snap ring 10 fixed to the clutch shaft 1, so the position of the snap ring 9 on the shaft is accurately determined, and the roller 31 reaches the over-center position shown in the upper half of Figure 1, the driven plate 5
The disk 16 can be reliably pressed against the disk 16.

That is, if an over-center mechanism as shown in the figure is adopted in order to apply clutch connection load to the pressure plate 17, the position of the roller 31 that can apply the maximum load (the position in the left-right direction in Fig. 1) is specified in a very narrow range. , hub 4
If the position of the hub 4 on the clutch shaft 1 is not securely fixed, a problem will occur in which a completely engaged state cannot be obtained, but according to the present invention, the hub 4 is attached to the snap ring 10.
Since it is directly positioned on the clutch shaft 1, it has the advantage of ensuring reliable operation.

Also, since the holder nut 22 of the over-center mechanism is screwed into the male threaded part 21 on the clutch shaft 1, when the driven plate 5, disc 16, etc. become worn, for example, remove the three pins 33 and replace the adapter. 24 to the right, the nut 22 is placed on the male threaded portion 21 by a predetermined distance, and then approached to the pressure plate 17 side, and then connected to the adapter 24 by the pin 33 again.

Incidentally, the disc spring 8 functions as a damper to reduce the rise in load at the initial stage of the clutch engagement stroke.

Further, there is no relative rotation between the disc spring 8 and the back plate 6, which has the advantage of reducing wear.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a clutch according to the present invention, FIG. 2 is a partial view taken along the line ■-■ in FIG. 1, and FIG. 3 is a view taken along the line ■-■ in FIG. 1...Clutch shaft, 3...Spline, 4...Hub, 5...Plate, 6...
... Back plate, 10 ... Snap ring, 13 ... Gear, 14 ... Housing, 16 ... Disc, 17 ...・・・
Pressure plate, 18...Return spring, 21...Male thread portion, 22...Holder nut, 28...Cam of overcenter mechanism.

Claims (1)

[Claims] 1. Fix a bottomed cylindrical oozing to the gear supported on the clutch shaft, attach the inner annular plate group to the cylindrical part of the housing so that it can only slide freely, and fit the bub to the spline on the clutch shaft. Then, a group of annular disks arranged alternately with plates is attached to the outer circumference of the bubble so that they can only slide freely, a back plate is attached to the gear side end of the outer circumference of the bubble, and the disk group is separated and a pressure plate is attached on the opposite side. Place the pressure plate on the clutch shaft with a spline, fit the return spring between the bub and the pressure plate, install a snap ring or protrusion that serves as a stopper for the bub on the spline, and attach the male thread on the clutch shaft. A clutch having an over-center mechanism, characterized in that a holder nut is screwed onto the nut, an over-center mechanism is provided on the nut to operate in response to a clutch operating force, and a pressure piece of the over-center mechanism is opposed to a pressure plate.