JPH0222499Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention mainly relates to a clutch disk for a friction clutch for a vehicle, and more particularly to a clutch disk using a torsion coil spring.

(Prior Art) A general clutch disk is elastically deformed in the compression direction due to relative angular displacement between the flange portion of the disk hub and the disk plates and sub-disk plates arranged on both sides thereof. It has a built-in torsion coil spring or torsion rubber. In other words, the clutch disk functions to absorb torque fluctuations and vibrations in the vehicle drive system through the elastic deformation of its torsion coil spring and torsion rubber.

In recent years, in order to deal with various phenomena in the vehicle drive system, there has been a tendency to set the characteristics of the clutch disc in multiple stages, as shown in FIG. 5, for example. In the region indicated by A in Fig. 5, the torsional rigidity (torsion torque) on the vertical axis is kept low relative to the angular displacement (torsion angle) of the clutch disk on the horizontal axis, and the hysteresis characteristics are also kept low. I'm suppressing it. This is a region in which vibrations in the drive system during idling of the vehicle, for example, are effectively suppressed.

(Problem that the invention aims to solve) In the conventional clutch disc, the oil temperature inside the transmission case is low, such as immediately after starting the engine.
When the resistance to rotation of each gear is large due to its viscosity, the above-mentioned twist angle of the clutch disk becomes large. As a result, even if the required characteristics of the clutch disc should be within the range of low torsional stiffness and low hysteresis shown by A in Fig. 5, it may reach the range shown by B in Fig. 5. . Therefore, a problem arises in that it is difficult to make the clutch disk exhibit the desired characteristics immediately after the engine is started.

(Means for solving the problems) In order to solve the above problems, the present invention is configured as follows. That is, in FIG. 1, the torsion coil spring 20 compressed by the relative angular displacement between the flange portion 2 of the clutch disk hub 1, the disk plate 6, and the sub disk plate 7 is replaced by the low-rigidity coil spring 22. It has a double structure with a combination of the coil spring 23 and the high-rigidity coil spring 23. Of both the coil springs 22 and 23, at least the high-rigidity coil spring 23 is made of a shape memory alloy that functions only when the ambient temperature is below a certain value.

(Function) In the above configuration, when the atmospheric temperature of the clutch disc exceeds a certain value, only the low-rigidity coil spring 22 functions as the torsion coil spring 20, and the atmospheric temperature of the clutch disc falls below a certain value. When lowered, the high-rigidity coil spring 23 made of the shape memory alloy
functions as a torsion coil spring 20. Therefore, when the above-mentioned ambient temperature is low and the rotational resistance due to the viscosity of the lubricating oil in the transmission case is high, the clutch disc exhibits high torsional rigidity, even when the engine is idling immediately after starting. It becomes possible to keep the characteristics of the clutch disk within the required range shown by A in FIG. 5, for example.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

First, in FIG. 1, which shows a partially broken half of the clutch disk, and FIG. 2, which shows a cross-sectional view taken along the line - in FIG. A disk plate 6 and a sub-disk plate 7 are arranged on both sides of this flange portion 2, respectively. These two disk plates 6, 7 are connected to each other by a stopper pin 8 at a plurality of notches 5 formed along the circumferential direction on the outer periphery of the flange portion 2. And these two disk plates 6, 7
and the flange portion 2 of the clutch disk hub 1 are capable of relative angular displacement within the range of the gap between the outer periphery of the stopper pin 8 and the inner periphery of both notches 5 of the flange portion 2.

A plurality of disk springs 9 are fixed to the outer periphery of the disk plate 6 along its circumferential direction with rivets 10, respectively. Further, facings 11 are fixed to both sides of the disk springs 9 by rivets 12.

Further, in the flange portion 2 of the clutch disk hub 1, a plurality of two types of windows 3 and 4 are formed along the circumferential direction, and the above-mentioned windows 3 and 4 are formed at locations corresponding to these windows 3 and 4. Windows are also formed in both disk plates 6 and 7, respectively (see FIG. 2). A torsion coil spring 20 and a torsion rubber 25 are provided in each window 3, 4 of this flange portion 2, and act in the compression direction by the above-mentioned relative angular displacement between this flange portion 2 and both disk plates 6, 7. Each is built in such a way that it can be received. Regarding this torsion rubber 25,
As is generally well known, it has a structure in which metal sheets 26 are fixed to both end surfaces of a rubber body 27 formed in a cylindrical shape. These two sheets 26 are connected to the inner peripheral edge of the window 4 in the flange portion 2,
The rubber body 27 receives an acting force between it and the inner circumferential edges of the windows of the disk plates 6 and 7 located correspondingly thereto in a direction that compresses the rubber body 27.

On the other hand, the above torsion coil spring 20
As is clear from FIG. 3, which is an enlarged view of the main part of FIG. 1, the window 3 of the flange portion 2
It is similar to the torsion rubber 25 in that it has a pair of sheets 21 that receive a force acting in the compressive direction between the inner peripheral edges and the corresponding inner peripheral edges of the windows of both disk plates 6 and 7. but,
This torsion coil spring 20 has a structure in which a low-rigidity coil spring 22 with a small spring constant and a high-rigidity coil spring 23 with a larger spring constant are double combined and interposed between the sheets 21. It is becoming.

Of these coil springs 22 and 23,
The low-rigidity coil spring 22 is always attached to both seats 2.
A normal coil spring is used that exerts an elastic force between 1 and 2. On the other hand, the high-rigidity coil spring 23 is made of a shape memory alloy, and when the ambient temperature around the clutch disk exceeds a certain value, it contracts as shown in FIG. It is in a state where it does not exhibit its elasticity. When the ambient temperature drops below a certain value, the high-rigidity coil spring 23 stretches as shown in FIG. 4 and exerts elastic force between the sheets 21 together with the low-rigidity coil spring 22. It is set as follows. Therefore, when the ambient temperature of the clutch disk is below a certain value, both the low-rigidity coil spring 22 and the high-rigidity coil spring 23 that constitute the torsion coil spring 20 are held between the two seats 21. It shows resilience.

In the clutch disk configured as described above, the clutch disk hub 1 and the facing 11
When a relative angular displacement occurs between the flange portion 2 and both disk plates 6 and 7 due to torque fluctuation between the two, the torsion coil spring 20 and the torsion rubber 25 are sequentially compressed in stages.
With this, the torsion coil spring 20
Based on the spring constant and hysteresis characteristics of the torsion rubber 25, the fifth clutch disc is
As shown in the figure, it exhibits multi-stage torsional characteristics. During normal running of the vehicle, the region indicated by A in FIG. 5, which has low torsional rigidity and low hysteresis, is frequently used.

Now, when the oil temperature in the gear transmission case is low and the rotational resistance due to its viscosity is large, such as immediately after starting the engine, the torsion angle of the clutch disk (between the flange portion 2 and both disk plates) shown on the horizontal axis in Fig. 6 and 7) becomes large. As a result, even when the clutch disk should exhibit the characteristics in the region A in FIG. 5, it may end up exhibiting the characteristics in the region B.

Incidentally, the oil temperature in the transmission case greatly affects the temperature in the clutch housing, that is, the ambient temperature around the clutch disc. In this embodiment, when the ambient temperature is below a certain value, the high-rigidity coil spring 23 made of a shape memory alloy constituting the torsion coil spring 20 is in the state shown in FIG. 3, as described above. It deforms into the state shown in FIG. 4, and functions as a torsion coil spring 20 together with the low-rigidity coil spring 22. Therefore, when the rotational resistance due to the viscosity of the lubricating oil in the transmission case is large, the clutch disc exhibits high torsional rigidity. This makes it possible to keep the characteristics of the clutch disc within the required range, for example, indicated by A in FIG. 5, even when the engine is idling immediately after starting.

In the above embodiment, only the high-rigidity coil spring 23 is made of a shape memory alloy, but if cost constraints are ignored, the low-rigidity coil spring 22 may also be made of a shape memory alloy. It is also possible. That is, when the ambient temperature of the clutch disk exceeds a certain value, only the low-rigidity coil spring 22 is activated, similar to the state shown in FIG. The high-rigidity coil spring 23 is set to function instead by contracting the high-rigidity coil spring 22. In this case, since the low-rigidity coil spring 22 and the high-rigidity coil spring 23 are operated alternately depending on whether the atmospheric temperature of the clutch disk is high or low, the torsional rigidity of the clutch disk is can be set in detail according to each situation.

(Effects of the invention) As described above, the present invention has a torsion coil spring of the clutch disk having a double structure consisting of a combination of a low-rigidity coil spring and a high-rigidity coil spring, and at least a high-rigidity coil spring. By making it made of a shape memory alloy that functions only when the ambient temperature is below a certain value, for example, when the oil temperature inside the transmission case is low and the rotational resistance due to its viscosity is large, such as immediately after the engine starts, By making the high-rigidity coil spring function, it is possible to exhibit greater torsional rigidity than at high temperatures. As a result, even during idling operation immediately after starting the engine,
It has the advantage that the desired characteristics for a clutch disk can be obtained, and that adjustments can be easily made to obtain appropriate characteristics in response to changes in the atmospheric temperature of the clutch disk.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, with FIG. 1 being a partially cutaway plan view showing half of the clutch disk, and FIG.
The figure is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view showing the main parts of Fig. 1, and Fig. 4 shows the state when the ambient temperature of the clutch disk is low. FIG. 5 is a cross-sectional view showing the relationship between the torsional angle and the torsional torque of the clutch disk. DESCRIPTION OF SYMBOLS 1...Clutch disc hub, 2...Flange part, 6...Disc plate, 7...Sub disc plate, 20...Torsion coil spring, 22...Low rigidity coil spring, 23...
...High rigidity coil spring.

Claims (1)

[Scope of utility model registration request] A torsion coil spring that is elastically deformed in the compression direction due to relative angular displacement between the flange portion of the clutch disk hub and the disk plate and sub-disk plate arranged on both sides thereof is incorporated. A clutch disk, wherein the torsion coil spring has a double structure consisting of a combination of a low-rigidity coil spring and a high-rigidity coil spring, and at least the high-rigidity coil spring has an ambient temperature below a certain value. A clutch disk characterized by being made of a shape memory alloy that only functions at certain times.