JPH02134419A - Viscous coupling - Google Patents

Abstract

PURPOSE:To make a large control range possible to be secured with a small shift stroke by installing a windowed zone, installing each through window in two sets of clutch cylinders, and also an windowed zone with no through window in a spot adjacent to the former. CONSTITUTION:A windowed zone A and unwindowed zone B are formed in each set of clutch cylinders 35, 41. In a shift stroke limit at the right, each of windowed zones A and unwindowed zones B is overlapped with each other, and torque transfer is carried out via a highly viscous fluid. When an output shaft 21 is shifted to the left from this state, the overlap area is decreased, therefore the torque transfer value is decreased as well, and when the windowed zone A to the clutch cylinder 41 is overlapped with the unwindowed zone B of the clutch cylinder 35, the torque transfer is not almost carried out. At this time, a large diametral part 23 of the output shaft 21 comes into contact with a end plate 7, setting the shift stroke limit at the left. With this constitution, the torque transfer is controllable with a small shift stroke, so that large energy for shift operation becomes disused as well.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a viscous coupling that is installed in the drive shaft system of a four-wheel drive vehicle, for example, and is capable of controlling transmission torque characteristics. .

(Prior Art) Such a viscous coupling is disclosed, for example, in Japanese Patent Application Laid-open No. 106130/1982, and FIG. 4 schematically shows its main components.

Referring to FIG. 4, it is assumed, for example, that the automobile is a front-wheel drive vehicle. A clutch housing 103 is coupled to an input shaft 101 that is rotationally driven from a front wheel drive system.
On the inner surface of one end wall of this housing 103, a first set of clutch cylinders 105 (105a,
105b, -) are fixed concentrically with the rotation center of the human power shaft 101.

Further, the output shaft 107 for transmitting power to, for example, the rear wheel drive system via the viscous coupling has a disc 1.
09 to the second set of clutch cylinders 111 (lla,
1llb, -) are fixed, and these are alternately combined with the first set of clutch cylinders 105 with wrap hairs attached.

The output shaft 107 extends outside the clutch housing 103 via an oil seal 113, and the range of maximum lap distance can be shifted by a shifter 115 formed on this extension. The clutch housing 103 is filled with viscous fluid, such as silicone oil, as a torque transmission medium from the clutch cylinder 105 to the clutch cylinder 111.

Therefore, the lap substitute changes according to the magnitude of the shift stroke, thereby adjusting the transmitted torque and controlling the amount of driving force distributed to the rear wheel drive system. And when the lap weight becomes almost zero, the power is not transmitted to the rear wheel drive system.

(Problem to be Solved by the Invention) However, in such a conventional viscous coupling, in order to expand the control range, the maximum wrap distance must be increased, and therefore the shift As the stroke becomes larger, the response to the control signal becomes slower, or if an attempt is made to increase the response, a large amount of energy is expended for the shift operation.

Therefore, an object of the present invention is to enable a large control range to be obtained even with a small shift stroke.

[Structure of the Invention] (Means for Solving the Problem) The means of the present invention for solving the problem is as follows: In a viscous coupling, a first set of clutch pipes is fixed to the other rotating body and a second set of clutch pipes are stacked alternately, and the first set and the second set of clutch pipes are stacked alternately. Each of the second set of clutch tubes has a windowed zone with a transparent window and a windowless zone adjacent to the windowed zone and substantially without a transparent window.

(Operation) According to this means, the windowless zones in the first and second sets of clutch cylinders overlap each other, and torque is transmitted at this overlapping portion. If the second set of clutch cylinders is shifted from this state by the width of the zone, the windowless zone and the windowed zone in both sets will overlap, so that no torque will be transmitted at this shift position. Therefore, the stroke limit on the other side can be set at the above shift position. Between the two stroke limits, the transmitted torque can be adjusted by adjusting the mutual shape of the windowless zones of both rotating bodies. In other words, the stroke for the control is approximately the width of the zone.

(Embodiment) An embodiment of the present invention will be described with reference to FIGS. 1 to 3.

As shown in Fig. 1, the input shaft 1 as one rotating body
A clutch housing 5 is fastened to the flange 1a with bolts 3. This clutch housing 5 includes an annular end plate 7 on the flange 1a side and a body shell 9 integrated with this end plate.
and an annular end plate 11 welded to the open end of this body shell. The output shaft 2 as the other rotating body is attached to the end plates 7 and 11.
1 are inserted so as to be able to rotate and slide relative to each other, and these insertion portions are sealed with X rings 17 and 17 (seal rings having an X-shaped cross section). In this state, the output shaft 21 has a large diameter portion 23 within the clutch housing 5.

By engaging the female spline formed at the center of the disk 31 with the male spline 25 formed on the end plate 7 side of the large diameter portion and positioning it with the wire circlip 33, 33, the disk 31 is attached to the end plate 7 side. It is to face each other. The first set of clutch cylinders 35 (
35a, 35b.

) and the second set of clutch cylinders 41 (41a, 41b
.

...) will be installed. Symbols X-X are input shaft 1 and output shaft 2
It is the common center of rotation with 1.

The first set of clutch cylinders 35 (35a, 35b).

), one end of which is fitted into an annular groove formed on the end plate 11 and concentric with the rotation center ,・
) are similarly fitted into annular grooves formed in the disk 31 and are sequentially arranged between the clutch cylinders 35 of the first set. This Figure 1 shows a state in which the output shaft 21 is at the shift stroke limit toward the end plate 11 side and the clutch tubes 35 and 41 are overlapped with each other with the maximum overlap. is regulated by the contact between the large diameter portion 23 and the end plate 11. Silicone oil as a viscous fluid is sealed inside the clutch housing 5.

Each set of clutch cylinders 35. In (41), a fenestrated zone A and a windowless zone B are formed as shown in FIG. That is, in this embodiment, the range instead of the maximum wrap is divided into five equal parts, and two windowed zones A and three windowless zones B are formed adjacent to each other in these divisional reprints. has four rectangular transparent windows 37 around its entire circumference.
．． (43) is repeated.

Therefore, at the right shift stroke limit, each windowed zone A and windowless zone B overlap, and torque is transmitted through the high viscosity fluid at the three overlapping portions of windowless zone B. When the output shaft 21 is shifted to the left from this state, the overlapping area decreases and the amount of torque transmitted decreases accordingly, and this shift amount becomes the width of zone A (B). When they become equal, as schematically shown in FIG. The left shift stroke limit is determined so that the large diameter portion 23 comes into contact with the end plate 7.

Reference numeral 45 is a shifter that controls the above shift, and the output shaft 21
A shift ring 49 is fitted between a pair of circlips 47 and 47 that are engaged with the circlips 47 and 47, and the shift ring 49 can be propelled left and right by a shift fork 51. Therefore, by adjusting the overlapping margin of the windowless zones B of both clutch tubes 35 and 41, the transmitted torque can be adjusted.

The shift fork 51 is driven by an actuator that responds to, for example, a mechanical signal from a transmission mechanism or is controlled by a control device, and may also be manually operated.

The structure and operation of the embodiment are as described above.

The windowed zone can also be configured by consecutively arranging a large number of square or circular transparent windows, and the windowless zone can be provided with transparent holes for increasing the transmitted torque. In addition, in the embodiment, the windowed and windowless zones of the clutch cylinders in both sets are formed to have equal widths so that they overlap accurately in the above-mentioned relationship at the shift stroke limit. It goes without saying that the relationship can be changed with appropriate flexibility according to the actual control situation, and the number of strips in each zone is not limited to this embodiment.

[Effects of the Invention] As explained above, according to the present invention, the transmitted torque is reduced by a small shift stroke that is sufficient to change the overlapping state of the windowed zone and the windowless zone formed in the first and second clutch cylinders. As a result, the responsiveness of the control can be improved without expending a large amount of energy for the shift operation.

[Brief explanation of the drawing]

Fig. 1 is a half-sectional view of a viscous coupling according to an embodiment of the present invention, Fig. 2 is a perspective view of the main part of Fig. 1, and Fig. 3 schematically shows one operating state of the above embodiment. 4 are diagrams schematically showing the main parts of a conventional viscous coupling. 1... Input shaft (one rotating body), 21... Output shaft (
the other rotating body), 35...first set of clutch cylinders, 41
...Second set of clutch tubes, A... Windowed zone, B...
... Windowless Zone Agent Patent Attorney Yasuo Miyoshi Figure 2 Figure 4

Claims (1)

[Claims] A first set of clutch cylinders fixed to one rotating body side and a first set of clutch cylinders fixed to the other rotating body side, which are provided so as to be able to shift a predetermined stroke with respect to this rotating body, are stacked alternately. In a viscous coupling equipped with a second set of clutch tubes, each of the first and second sets of clutch tubes has a windowed zone with a transparent window, and a windowed zone adjacent to this windowed zone. A viscous coupling that has a windowless zone with no transparent window.