JPS61286623A - Viscous coupling device - Google Patents

Abstract

PURPOSE:To enable the prevention of reduction in a torque transmission efficiency by making disk plates deform so that disk plates are connected mutually when the temperature of viscous fluid rises. CONSTITUTION:When the temperature of a viscous fluid enclosed in a working housing 3 rises, the viscosity of the viscous fluid decreases, and at this time inner disk plates 15 deform in a disk--spring shape which the inner disk plates memorize. By this deformation of inner disk plates, the mutual connection of disk plates 13 and 15 are caused. Accordingly, since the housing 3 and an output part 7 are promptly connected to be integrated, the torque being input in the first shaft 1 is efficiently transmitted to the second shaft 9.

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to a viscous coupling coupling used in automobile power transmission devices, etc. l? Regarding this.

[Technical background and problems]

As a conventional viscous coupling device of this type, there is one described, for example, in Japanese Patent Application Laid-Open No. 58-50349. That is, it is composed of a housing that receives a rotational input and a pair of left and right shafts that are rotatably supported by the housing, and a differential chamber that is formed in a sealed manner is provided between the housing and the shaft. Inside the differential chamber,
A disc plate is filled with viscous fluid such as silicone oil and is movable in the axial direction and is engaged in the inner circumferential direction with the inner peripheral wall of the housing.The disc plate is engaged in the circumferential direction with the outer circumference of the shaft and moves in the axial direction. possible disc plates are arranged alternately.

The rotational force input to the housing is transmitted from the disc plate on the housing side, which rotates integrally with the housing, to the disc plate on the shaft side due to the viscosity of silicone oil sealed in the differential chamber of the housing, and is transmitted to the left and right shafts. communicated.

The torque transmission capacity of the viscous coupling device configured in this way is determined by the viscosity of the silicone oil sealed in the working chamber and the area of the housing-side disc plate and shaft-side disc plate that are combined in the silicone oil. Determined by mutual distance.

However, in such conventional viscous coupling devices, the viscosity of the silicone oil sealed in the working chamber of the housing is affected by temperature changes.

That is, when silicone oil becomes hot, its viscosity decreases, resulting in a problem of increased torque transmission loss.

[Purpose of the invention]

This invention was devised to solve the problems in view of the conventional circumstances, and it changes the shape of the disk plate in response to the temperature rise of the viscous fluid, thereby improving the torque transmission efficiency. The purpose of the present invention is to provide a viscous coupling device that can improve the performance.

[Summary of the invention]

The present invention provides a plurality of disc plates located in a sealed working chamber formed between a first shaft and a second shaft that are relatively rotatable and filled with a viscous fluid. In the viscous coupling device configured to engage with each other, a plate body that can be actuated and deformed at each of a plurality of temperatures due to temperature changes in the viscous fluid is interposed between the plurality of disk plates.

〔Example〕

Hereinafter, the structure of the present invention will be explained based on an embodiment shown in FIGS. 1 and 2.

A first shaft 1 receiving rotational input is fixed to one side wall 3a of the housing 3 via a bolt 5. An output member 7 is rotatably supported by the housing 3a, and a second shaft 9 that outputs rotational force is connected to the output member 7 by spline fitting or the like.

A sealed working chamber 11 is provided between the housing 3 that connects the first shaft 1 and the output member 7 that connects the second shaft 9. A viscous fluid is enclosed.

Inside the working chamber 11 are a plurality of outer disk plates 13 which are engaged in the circumferential direction by meshing with splines formed on the inner circumferential wall of the housing 3 and are movable in the axial direction. , a plurality of inner disk plates 15 that are engaged in the circumferential direction by meshing with splines formed on the outer periphery of the output member 7 and are movable in the axial direction are arranged alternately.

The inner disk plate 15 is made of a shape memory alloy, and can be deformed into two forms: a flat plate shape at room temperature (see Figure 1) and a disc spring shape at high temperatures (see Figure 2). The shape change temperature is set differently for each disk plate 15. That is, the inner disk plate 15 itself is formed into a plate that can be deformed by changes in the temperature of the viscous fluid.

Next, the operation of one embodiment of the present invention constructed as above will be described.

The rotational force input to the first rotating shaft 1 is transmitted to the housing 3 and further transmitted to the outer disc plate 13 engaged with the housing 3, causing this disc plate 13 to rotate, but the rotation of the outer disc plate 13 is The inner disk plate 15 is rotated via the viscous fluid sealed in the working chamber 11, and as the inner disk plate 15 rotates, the output member 7 and the output member 7 that engage with the inner disk plate 15 are rotated.
It is transmitted to the second shaft 9 that engages with the second shaft 9, and is outputted from the second shaft 9.

In the torque transmission performed in this way, the working chamber 3
When the temperature of the viscous fluid sealed therein increases, the viscosity of the viscous fluid decreases, and at this time, the inner disk plate 15 deforms into a memorized disc spring shape, as shown in FIG. This deformation of the inner disk plate 15 causes the disk plates 13.15 to be fastened together.

In this way, the inner disk plate 15 is deformed due to the temperature change of the viscous fluid and is fastened to the outer disk plate 13. However, in this embodiment, the inner disk plate 15 is made of a shape memory alloy.
The deformation of the individual inner disk plates 15 takes place as soon as the set temperature is reached, and the fastening with the outer disk plates 13 takes place quickly, while the inner disk plates 15
Since the temperature of shape change is set differently for each,
It does not deform all at once, but deforms at different times for each set temperature and is fastened to the outer disk plate 13. Therefore, since the housing 3 and the output member 7 are quickly fastened and integrated, the rotational force input to the first shaft 1 is efficiently transmitted to the second shaft 9, and the inner disc plate 15 does not cause sudden load fluctuations, and gentle torque control is performed in response to temperature changes, resulting in stable torque transmission with little pulsation.

Also, when fastening the disc plates 13 and 15,
Since the elastic force of the deforming inner disk plate 15 is present, the change in torque transmission from the first shaft 1 to the second shaft 9 due to the fastening of both becomes gradual, and the shock can be reduced.

Then, when the temperature of the viscous fluid decreases to room temperature, the inner disk plate 15 returns to its flat shape, and the original torque transmission performance can be obtained.

Note that this invention is not limited to the above embodiment.

For example, the interposed plate may be made of bimetal, or may be made of a combination of a shape memory alloy and bimetal. When a shape memory alloy and a bimetal are combined, as shown in Figure 4, the increase in deformation due to a temperature rise in the bimetal is proportional to the temperature change, whereas the increase in the temperature of the shape memory alloy The increase in the amount of deformation caused by
The bimetal actuates and deforms the parts where it is desired to gradually compensate for the decrease in viscosity of the viscous fluid due to temperature rise, while the shape memory alloy acts and deforms in the parts where rapid correction is desired. You can also do it.

It is also possible to interpose the plate separately from the disc plate 13.15. In this case, one or more plates are sufficient.

Further, in the above embodiment, the inner disk plate 15 is formed so as to be deformable into two shapes: a flat plate shape at room temperature and a disc spring shape at high temperature; however, the outer disk plate 15 is not limited to this. Both the plate 13 and the inner disk plate 15, or only the outer disk plate 13 may be formed. When both disc plates 13 and 15 are made deformable, they can be configured so that they are all disc springs facing in the open direction at room temperature, and one becomes flat when the temperature rises, or both can be made into a flat plate at room temperature. However, it is also possible to configure them so that they deform in opposite directions as the temperature rises.

Further, in the above embodiment, the outer disk plates 13 and the inner disk plates 15 are arranged alternately in series, but as shown in FIG. 3, a plurality of disk plates are arranged in parallel on one side in succession. But that's fine. In this case, when the disc plates deform into a disc spring shape due to temperature rise, it is possible to have a large load capacity in a small space compared to those arranged in series, so the disc plates can More reliable fastening is achieved, and torque can be transmitted more efficiently.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, when the temperature of the viscous fluid rises, the disc plates, which have different set temperatures for shape change each time the temperature changes, deform and the disc plates are fastened together. Therefore, it is possible to prevent a decrease in torque transmission efficiency despite the decrease in the viscosity of the viscous fluid, and also to prevent sudden load fluctuations due to changes in the shape of the disk plate, and to respond to temperature changes. Gentle torque control is performed,
Stable torque transmission with less pulsation can be achieved.

Furthermore, since the capacity can be set arbitrarily, the degree of freedom in design can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a viscous coupling device according to an embodiment of the present invention, FIG. 2 is a sectional view showing the operating state of the viscous coupling device, and FIG. 3 is a sectional view showing another embodiment. Figure 4 is a characteristic comparison diagram between shape memory alloy and bimetal. 1...1st axis 9...2nd axis 11...working chamber 13...outer disk plate 15...inner disk plate (celestial body) Fig. 2 1...1st axis 9...2nd axis] 1.・Working chamber 13・・Outer 11 disk plate 15・・Inner 11 disk plate (I, body) 1st
figure

Claims (2)

[Claims] (1) Located in a sealed working chamber formed between a first shaft and a second shaft that are relatively rotatable and filled with viscous fluid, a plurality of disc plates are respectively engaged with the first shaft and the second shaft. A viscous coupling device configured by combining the plurality of disk plates, wherein a plate body is interposed between the plurality of disk plates, which can be actuated and deformed at each of a plurality of temperatures due to temperature changes in the viscous fluid. Device. (2) The viscous coupling device according to claim 1, wherein the plate body is constituted by at least one of a disk plate that is engaged with the first shaft or the second shaft.