JP7599323B2 - Damper Device - Google Patents

Description

The present invention relates to a damper device, in particular, a damper device disposed between a prime mover and a transmission.

The clutch disc assembly used in a vehicle has a clutch disc that is pressed against a flywheel, and a damper device. The damper device transmits the torque transmitted from the engine via the clutch disc to the transmission, and also damps engine rotation fluctuations.

This type of damper device is shown in Patent Document 1. The damper device in Patent Document 1 includes an input rotor, an output rotor, and an elastic connecting portion. The input rotor and the output rotor are coaxial and can rotate about the same rotation axis. The elastic connecting portion has a number of coil springs, which are arranged in a compressed state between the input rotor and the output rotor.

The damper device of Patent Document 1 restricts the input rotor from rotating relative to the output rotor when the engine is started until it reaches an idle state, and when the engine is stopped from an idle state. This suppresses vibrations and noise caused by resonance of the damper device when the engine is started and stopped.

JP 2016-133123 A

In the damper device of Patent Document 1, the coil spring that connects the input rotor and the output rotor is mounted in a pre-compressed state. In other words, the coil spring is preloaded. This preload on the coil spring prevents the input rotor and the output rotor from twisting when the torque is low during engine start-up and shutdown.

Here, particularly in vehicles with small displacement, for example, a 3-cylinder engine with a displacement of about 1000 cc, it may be desirable to improve drivability by limiting the function of the damper device to a degree that does not impair the damping performance of rotational vibration when the engine torque is low, and to allow the damper device to function when the engine torque is high and the vehicle is running in high gear.

In addition, to effectively damp engine rotation fluctuations, it is preferable to reduce the torsional rigidity of the damper device (specifically, the rigidity of the coil spring). In order to reduce the torsional rigidity and ensure a certain torque transmission capacity, it is necessary to widen the torsional angle. However, in order to widen the torsional angle, the size of the device increases. In addition, a wide torsional angle leads to early wear of the friction members that generate hysteresis torque.

The objective of the present invention is to improve drivability in a damper device without impairing the damping performance of rotational vibrations at low torque, and to damp rotational fluctuations when driving at relatively high torque, while avoiding an increase in the size of the device.

(1) The damper device according to the present invention is disposed between a prime mover and a transmission. This damper device includes an input rotor, an output rotor, and an elastic connecting portion. The input rotor is connected to a member on the prime mover side. The output rotor is rotatable relative to the input rotor within a predetermined torsional angle range, and is connected to a member on the transmission side. The elastic connecting portion has a predetermined torsional characteristic, transmits torque between the input rotor and the output rotor, and damps rotational fluctuations of the prime mover.

The torsional characteristics of the elastic connecting part have a first stiffness in a first torque range in which the input torque from the prime mover is from 0 to any torque between 10% and 70% of the maximum torque, and have a second stiffness lower than the first stiffness in a second torque range beyond the first torque range.

Here, the torsional characteristics of the elastic connecting portion have a first stiffness higher than the second stiffness in the first torque range. Therefore, if the first stiffness is made rigid (effectively a connection in a state where there is no elastic deformation in the elastic connecting portion) or a very high stiffness, drivability in the first torque range is improved. In addition, since the second stiffness is low in the second torque range, rotational fluctuations of the prime mover during driving can be effectively damped. Furthermore, since the first stiffness is high, the desired torque transmission capacity can be obtained without widening the torsional angle. Therefore, it is possible to avoid an increase in the size of the device. In addition, since it is possible to avoid widening the torsional angle, when a mechanism for generating hysteresis torque is provided, wear of the friction members constituting the mechanism can be suppressed.

(2) Preferably, the first stiffness is 1.5 times or more the second stiffness.

(3) Preferably, the damper device further includes a stopper mechanism that prohibits relative rotation between the input rotor and the output rotor when the input torque is equal to or greater than the stopper torque. In this case, the upper limit of the first torque range is 7% to 60% of the stopper torque.

(4) Preferably, the elastic coupling is provided between the input rotor and the output rotor and has a plurality of elastic members for transmitting torque. In this case, at least one of the plurality of elastic members is pre-compressed and attached.

(5) Preferably, the elastic member is a coil spring, and the output rotor has a housing portion for housing the coil spring. In this case, the free length of the pre-compressed coil spring is 1.02 times or more and 1.43 times or less the width of the housing portion.

(6) A damper device according to another aspect of the present invention is disposed between a prime mover and a transmission. This damper device includes an input rotor, an output rotor, and an elastic connecting portion. The input rotor has a plurality of windows, and is connected to a member on the prime mover side. The output rotor has a plurality of window holes at positions corresponding to the plurality of windows, is rotatable relative to the input rotor within a predetermined torsional angle range, and is connected to a member on the transmission side. The elastic connecting portion has a plurality of elastic members attached to the windows and the window holes, and elastically connects the input rotor and the output rotor in the rotational direction.

At least one of the multiple elastic members is pre-compressed and attached. When the input rotor and the output rotor are not rotating relative to each other, only the radially inner side of the circumferential end face of the pre-compressed elastic member abuts against the circumferential end of at least one of the window portion and the window hole, and when the input rotor and the output rotor are rotating relative to each other by a predetermined angle, both the radially inner and outer sides abut against the circumferential end of at least one of the window portion and the window hole.

Here, at least one of the multiple elastic members is pre-compressed and attached. When the input rotor and the output rotor are twisted, the pre-compressed elastic member is first pressed only on the radially inner side of its end face, and as the twist angle increases, both the radially inner and outer sides are pressed.

Therefore, when low torque is input from the prime mover to the damper device, the torsional characteristics of the elastic connection part can be set to a very high rigidity without impairing the damping performance of the rotational fluctuation. Therefore, when the torque from the prime mover is low, it is possible to improve drivability while suppressing the rotational fluctuation.

In addition, when high torque is input from the prime mover, the torsional characteristics can be made low rigidity, effectively damping the rotational fluctuations of the prime mover while driving.

(7) Preferably, at least one of the window portion and the window hole to which the pre-compressed elastic member is attached has an opening angle at the circumferential end face that opens from the radially inner side toward the radially outer side. When the input rotor and the output rotor are not rotating relative to each other, a gap is formed between the radially outer portion of the window portion and/or the window hole having the opening angle and the elastic member.

(8) Preferably, all of the multiple elastic members are pre-compressed and attached to the window holes, and all of the multiple window holes have the opening angle.

The present invention as described above improves drivability at low torque and effectively damps rotational fluctuations when driving at relatively high torque. The present invention also makes it possible to avoid an increase in the size of the device. Furthermore, by setting the first rigidity to a very high rigidity, damper operation at low torque can be almost completely eliminated, reducing the amount of sliding of the hysteresis torque generating parts (friction members), and achieving stable hysteresis torque over the long term.

1 is a cross-sectional view of a clutch disk assembly having a damper device according to an embodiment of the present invention; FIG. 2 is a front view of the clutch disk assembly of FIG. 1 . FIG. 3 is an enlarged partial view of FIG. 2 . 4 is a torsional characteristic diagram of the damper device. 1 is a cross-sectional view of a torque converter with a lock-up clutch having a damper device according to an embodiment of the present invention;

[composition]
Fig. 1 is a cross-sectional view of a clutch disc assembly 1 having a damper device according to one embodiment of the present invention. Fig. 2 is a front view of the same. The clutch disc assembly 1 is disposed between the engine and transmission of a vehicle. In Fig. 1, line O-O is the rotation axis of the clutch disc assembly 1. The engine and flywheel (not shown) are disposed on the left side of Fig. 1, and the transmission (not shown) is disposed on the right side of Fig. 1.

In the following description, the axial direction is the direction in which the rotation axis O of the clutch disk assembly 1 extends. The circumferential direction is the circumferential direction of a circle centered on the rotation axis O, and the radial direction is the radial direction of a circle centered on the rotation axis O. The circumferential direction does not have to be completely consistent with the circumferential direction of a circle centered on the rotation axis O, and is a concept that includes, for example, the left-right direction based on the window portion and window hole shown in FIG. 3. The radial direction does not have to be completely consistent with the diameter direction of a circle centered on the rotation axis O, and is a concept that includes, for example, the up-down direction based on the window portion and window hole shown in FIG. 3.

The clutch disk assembly 1 includes a clutch section 2 and a damper section 3 (an example of a damper device). The damper section 3 includes an input rotor 5, an output rotor 6, an elastic connecting section 7, a stopper mechanism 8 (see FIG. 2), and a hysteresis generating mechanism 9.

The clutch portion 2 has a cushioning plate 11 and a pair of friction facings 12. The cushioning plate 11 has an annular portion 11a and a plurality of cushion portions 11b that protrude radially outward from the annular portion 11a. The pair of friction facings 12 are annular and are fixed by rivets 13 on both axial sides of the cushion portions 11b.

The input rotor 5 has a clutch plate 15 and a retaining plate 16. The clutch plate 15 and the retaining plate 16 are both disc-shaped, annular members made of sheet metal, and are arranged at a predetermined distance from each other in the axial direction. The clutch plate 15 is arranged on the engine side, and the retaining plate 16 is arranged on the transmission side. The two plates 15, 16 are fixed by four stop pins 17 so that they cannot rotate relative to each other and cannot move axially. This allows the clutch plate 15 and the retaining plate 16 to rotate together.

The clutch plate 15 and the retaining plate 16 each have a central hole. In addition, the clutch plate 15 and the retaining plate 16 each have four windows 15a, 16a aligned in the circumferential direction. Each window 15a, 16a has the same shape and is formed at the same radial position. Each window 15a, 16a extends generally circumferentially. Each window 15a, 16a also has a hole penetrating in the axial direction and a support portion formed along the edge of the hole.

The output rotor 6 is a member that receives torque from the input rotor 5 via the elastic coupling 7 and outputs the torque to an input shaft of a transmission (not shown). The output rotor 6 is rotatable relative to the input rotor 5 within a predetermined angle range, and has a boss 20 and a flange 21.

The boss 20 is cylindrical and is disposed within the central holes of the clutch plate 15 and the retaining plate 16. A spline hole 20a is formed on the inner peripheral surface of the boss 20, and this spline hole 20a can be splined to the input shaft of the transmission.

The flange 21 is roughly disk-shaped and extends radially outward from the outer circumferential surface of the boss 20. The flange 21 is disposed axially between the clutch plate 15 and the retaining plate 16. Four window holes 21a are formed in the flange 21 at positions corresponding to the window portions 15a, 16a of the clutch plate 15 and the retaining plate 16. Each window hole 21a is a hole punched in the axial direction and extends long in the circumferential direction.

Figure 3 shows an enlarged view of the window hole 21a. As shown in Figure 3, both end faces 21c of the window hole 21a in the circumferential direction have an opening angle D. In other words, the end faces 21c of the window hole 21a open from the radial inside to the radial outside.

Here, the opening angle D is the angle between a straight line C that connects the center of rotation O and the center of the width of the window hole 21a, and the circumferential end face 21c of the window hole 21a. The straight line C is also parallel to the end face 24a of the coil spring 24, which will be described later. Therefore, the opening angle D is also the angle between the end face 24a of the coil spring 24 and the circumferential end face 21c of the window hole 21a.

In FIG. 3, the opening angle is shown larger than the actual angle for ease of understanding. The actual opening angle is set to, for example, 0.5 degrees, but this opening angle is set appropriately depending on the specifications of the engine in which the damper device is installed.

As shown in FIG. 2, a notch 21b having a predetermined width in the circumferential direction is formed on the outer peripheral edge of the flange 21. A stop pin 17 passes through this notch 21b in the axial direction. This notch 21b and the stop pin 17 form a stopper mechanism 8. In other words, the stop pin 17 abuts against the circumferential end face of the notch 21b, thereby prohibiting relative rotation between the input rotor 5 and the output rotor 6.

The elastic connecting part 7 has a predetermined torsional characteristic, and is a mechanism for transmitting torque between the input rotor 5 and the output rotor 6, and for damping engine rotation fluctuations. The elastic connecting part 7 has four coil springs 24. Each coil spring 24 is mounted in a pre-compressed state in the window hole 21a of the flange 21.

Here, as shown in FIG. 3 and described above, the end face 21c of the window hole 21a has an opening angle D. Therefore, when the relative rotation angle between the input rotor 5 and the output rotor 6 is "0" (when there is no twist between them), only a radially inner portion of the end face 24a of the coil spring 24 abuts against the end face 21c of the window hole 21a, and the remaining portion is away from the end face 21c of the window hole 21a, forming a gap between the two.

In this embodiment, all four coil springs 24 have the same free length L. The free length L is 1.20 times (L = 1.20 x W) the circumferential width W of the window hole 21a (the width at the radial center).

The free length L of the coil spring 24 is preferably 1.02 to 1.43 times the width W of the window hole (L = (1.02 to 1.43) x W). If the free length L is less than 1.02 times the width W of the window hole, the improvement in drivability during driving at low torque decreases. If the free length L exceeds 1.43 times the width W of the window hole, the stress during operation of the coil spring increases, shortening the life of the coil spring.

The hysteresis generating mechanism 9 generates hysteresis torque, which is friction resistance in the rotational direction, when the input rotor 5 and the output rotor 6 rotate relative to each other. The hysteresis generating mechanism 9 has a first bush 26, a second bush 27, and a cone spring 28.

The first bush 26 is disposed between the inner periphery of the clutch plate 15 and the flange 21. The first bush 26 has multiple engagement protrusions 26a that protrude in the axial direction. These engagement protrusions 26a engage with holes formed in the clutch plate 15. Therefore, the first bush 26 rotates together with the clutch plate 15 and is in frictional contact with the flange 21.

The second bush 27 is disposed between the inner periphery of the retaining plate 16 and the flange 21. The second bush 27 has a number of engagement protrusions 27a that protrude in the axial direction. These engagement protrusions 27a engage with holes formed in the retaining plate 16. Therefore, the second bush 27 rotates together with the retaining plate 16 and makes frictional contact with the flange 21.

The cone spring 28 is arranged in a compressed state between the second bush 27 and the retaining plate 16. The cone spring 28 presses the first bush 26 and the second bush 27 against the flange 21.

[Action]
The operation of the clutch disk assembly 1 will be described with reference to the torsional characteristic diagram shown in Fig. 4. In Fig. 4, Ti is the torque (initial torque) at which the coil spring 24 is actuated (a state in which the coil spring 24 is further compressed from the pre-compressed state) by the pre-compression of the coil spring 24. Also, Ts is the torque (stopper torque) at which the stopper mechanism 8 is actuated.

When the torque input from the engine is low, specifically in the first torque range from 0 (N·m) to the initial torque Ti, the coil spring 24 is compressed and preloaded in advance, so it exhibits a high first rigidity (torsion characteristic A).

More specifically, when the torque from the engine is in the first torque range, first, only the radially inner side of the end face 24a of the coil spring 24 is pressed by the end face 21c of the window hole 21a. Then, when the torsion angle becomes θ, both the radially inner and outer sides of the end face 24a of the coil spring 24 come into contact with and are pressed by the end face 21c of the window hole 21a. This operation results in the torsion characteristic A in Figure 4.

In this example, the initial torque Ti corresponds to the free length L of the coil spring 24 being 1.2 times the circumferential width W of the window hole (L = 1.20 x W). Here, it is preferable that the free length L of the coil spring 24 is 1.02 to 1.43 times the width W of the window hole (L = (1.02 to 1.43) x W), in which case the initial torque Ti corresponds to 10% to 70% of the maximum torque of the engine.

Next, in a second torque range where the torque from the engine exceeds the initial torque Ti, the coil spring 24 operates, and torque is transmitted between the input rotor 5 and the output rotor 6 with the torsional characteristic of the second stiffness set by the coil spring 24 (torsional characteristic B). Here, the first stiffness is preferably 1.5 times or more the second stiffness, and the first stiffness also includes the case where it is rigid.

Due to the torsional characteristics described above, when driving at a relatively low torque up to the initial torque Ti, the high-rigidity torsional characteristic A of the first rigidity can suppress rotational fluctuations while improving drivability. On the other hand, when driving in a torsional angle range exceeding the initial torque Ti, the low-rigidity torsional characteristic B of the second rigidity can effectively dampen engine rotational fluctuations.

The torsional characteristic C in FIG. 4 is a characteristic for achieving the stopper torque Ts when the coil spring 24 is not pre-compressed. As is clear from a comparison of characteristics B and C, in this embodiment, a low-rigidity torsional characteristic can be achieved when driving with a relatively high torque.

The initial torque Ti can also be set as a percentage of the stopper torque Ts. In this embodiment, the initial torque Ti is 42% of the stopper torque Ts. It is also preferable that the initial torque Ti is 7% or more and 60% or less of the stopper torque.

[Other embodiments]
The present invention is not limited to the above-described embodiments, and various modifications and alterations are possible without departing from the scope of the present invention.

(a) In the above embodiment, the elastic connecting portion 7 is configured with four coil springs 24, but the number of coil springs 24 is not limited to this example.

(b) In the above embodiment, the four coil springs 24 are pre-compressed before installation, but for example, two of the four coil springs may be pre-compressed before installation, and the remaining two coil springs may be installed without pre-compression.

(c) In the above embodiment, the present invention is applied to a clutch disk assembly, but the present invention can also be similarly applied as a damper device for another power transmission device.

Figure 5 shows an example in which the damper device of the present invention is applied to a lock-up clutch of a torque converter. In Figure 5, the torque converter 50 includes a torque converter body 51 and a lock-up clutch 52.

The torque converter body 51 has a well-known structure and includes an impeller 55, a turbine 56, and a stator 57. The impeller 55 is connected to a front cover 58, and the turbine 56 can be connected to a shaft of a transmission (not shown).

The lock-up clutch 52 has a piston 61 and a damper section 62. The damper section 62 has a different specific shape, but is basically the same structure as the damper section 3 shown in FIG. 1. That is, the damper section 62 has a pair of input plates 65 (corresponding to the input rotor 5 in FIG. 1), an output plate 66 (corresponding to the output rotor 6 in FIG. 1), multiple springs 67 (corresponding to the elastic connecting section 7 in FIG. 1), and a hysteresis generating mechanism 69 (corresponding to the hysteresis generating mechanism 9 in FIG. 1).

Even with a lock-up clutch 52 having such a damper portion 62, the same effects as those of the above embodiment can be obtained.

3 Damper portion 5 Input rotor 6 Output rotor 7 Elastic coupling portion 8 Stopper mechanism 15a, 16a Window portion 21a Window hole 24 Coil spring

Claims (6)

A damper device disposed between a prime mover and a transmission,
an input rotor connected to the prime mover side member;
an output rotor that is rotatable relative to the input rotor within a predetermined torsion angle range and is connected to a member on the transmission side;
an elastic coupling portion having a predetermined torsional characteristic, for transmitting torque between the input rotor and the output rotor and for attenuating rotation fluctuation of a prime mover;
Equipped with
The torsional characteristic of the elastic connecting portion has a first stiffness in an entire angle range in which the input torque from the prime mover is in a first torque range from 0 to any torque between 10% and 70% of the maximum torque and the torsional angle between the input rotor and the output rotor is in a range from 0 degrees to a first torsional angle, and has a second stiffness lower than the first stiffness in a second torque range beyond the first torque range and in a range in which the torsional angle exceeds the first torsional angle,
the elastic coupling portion is provided between the input rotor and the output rotor and includes a plurality of coil springs for transmitting torque,
At least one of the plurality of coil springs is mounted pre-compressed;
the output rotor has a window hole for accommodating the coil spring,
The free length of the pre-compressed coil spring is greater than or equal to 1.02 times and less than or equal to 1.43 times the width of the window hole.
Damper device.
The damper device according to claim 1 , wherein the first stiffness is at least 1.5 times the second stiffness.
a stopper mechanism that prohibits relative rotation between the input rotor and the output rotor when an input torque is equal to or greater than a stopper torque;
an upper limit value of the first torque range is 7% or more and 60% or less of the stopper torque;
The damper device according to claim 1 or 2.
A damper device disposed between a prime mover and a transmission,
an input rotor having a plurality of windows and connected to a member on the prime mover side;
an output rotor having a plurality of window holes at positions corresponding to the plurality of window portions, the output rotor being rotatable relative to the input rotor within a predetermined torsional angle range, and the output rotor being connected to a member on the transmission side;
an elastic coupling portion having a plurality of elastic members attached to the window portion and the window hole, the elastic coupling portion elastically coupling the input rotor and the output rotor in a rotational direction;
Equipped with
At least one of the plurality of elastic members is mounted pre-compressed;
The circumferential end surface of the pre-compressed elastic member is
When the input rotor and the output rotor are not rotating relative to each other, only the radially inner side of the window portion and the window hole contacts a circumferential end of at least one of the window portion and the window hole,
when a torsion angle between the input rotor and the output rotor becomes a first torsion angle, both a radial inner side and a radial outer side abut against a circumferential end of at least one of the window portion and the window hole,
the elastic connecting portion has a torsional characteristic due to the plurality of elastic members,
The torsional characteristic has a first stiffness in an entire angle range from 0 degree to a first torsional angle, and has a second stiffness lower than the first stiffness when the torsional angle exceeds the first torsional angle.
Damper device.
At least one of the window portion and the window hole to which the pre-compressed elastic member is attached has an opening angle at a circumferential end surface that opens from the radially inner side toward the radially outer side,
When the input rotor and the output rotor are not rotating relative to each other, a gap is formed between the elastic member and a radially outer portion of the window portion and/or the window hole having the opening angle.
The damper device according to claim 4 .
The plurality of elastic members are all pre-compressed and installed in the window holes,
All of the plurality of window holes have the opening angle.
The damper device according to claim 5 .

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