JPH10169755A - Hydraulic power transmission with direct coupled clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain newly generating vibration due to additional dynamic damper function by a simply changed structure. SOLUTION: In this hydraulic power transmission with a direct coupled clutch having a damper mechanism, a turbine hub 6B as a mass is connected to a driven plate 28, which is located at the downstream side of a power transmission passage beyond the damper mechanism to contribute to torque transmission when the direct coupled clutch is in the operated condition, via an inside damper spring 46 to form a dynamic damper. The inside damper spring 46 is assembled between the driven plate 28 and the turbine hub 6B in the pre- loaded condition so that it can be elastically deformed only when torque exceeds a preset value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid transmission with a direct connection clutch having a damper function.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 61-252958
In a torque converter (fluid power transmission) with a direct coupling clutch, a damper such as a torsion spring is used to suppress torque fluctuation from the engine when the direct coupling clutch is activated (when the clutch is engaged). A mechanism is provided.

In this case, the torsional rigidity of the damper mechanism should be set low in order to extend the directly-connected traveling range to a lower vehicle speed range (for improving fuel efficiency).

[0004] This will be described using a simplified model of a vibration transmission system shown in FIG.

In FIG. 9, I1 is an inertia moment of the engine and the primary side of the automatic transmission (from the input side of the automatic transmission to the damper mechanism of the direct-coupled clutch: upstream of the damper mechanism).
Reference numeral 2 denotes a moment of inertia on the secondary side of the automatic transmission (downstream of the damper mechanism), and B denotes a vehicle body. K1 represents the torsional rigidity of the damper mechanism of the direct coupling clutch, K2 represents the torsional rigidity of the drive shaft, F1 represents the damping term due to friction, and V1 and V2 represent the damping terms due to speed.

In the case of direct running, for example, in the case of a four-cylinder engine, there is a primary mode resonance point where the inertia moments I1 and I2 vibrate in the same phase near 300 rpm, and 1000 rp.
Near m, there is a second mode resonance point where the moments of inertia I1 and I2 vibrate in opposite phases. Of these, the primary mode resonance point is out of the usable range of the engine and therefore does not cause a problem. The secondary mode resonance point becomes a problem during actual direct running.

Therefore, it can be seen that in order to extend the directly connectable region to the low vehicle speed region, the engine speed at the secondary mode resonance point should be set as low as possible. Conventionally,
As a method of lowering the secondary mode resonance point, a method of reducing the torsional rigidity K1, K2 and a method of reducing the inertia moments I1, I2
Methods have been proposed to optimize the distribution of the two.

In the prior art disclosed in Japanese Patent Application Laid-Open No. 61-252958, the torsional rigidity K1 is reduced by using a compression coil spring having a small spring constant and a large stroke length.

[0009]

However, all of the conventional methods have physical limitations, and there is a limit in expanding the directly connectable region to a low vehicle speed region. This is because there is a limit in reducing the torsional rigidity K1 of the damper mechanism due to space limitations, while it is practically impossible to significantly reduce the torsional rigidity K2 of the drive shaft.

Also, regarding the distribution of the moments of inertia I1 and I2, it is almost impossible to set them freely because of the structure, and a compromise has to be made with a predetermined value.

For example, if the inertia moment I1 is to be reduced, the vibration of the engine and the primary side of the automatic transmission increases, causing so-called "squeal" of the accessory drive belt and a problem in durability.

[0012] In order to solve these problems, the present applicant has already disclosed in Japanese Patent Application No. 7-280211 (unknown) the need to increase the weight and accommodation space of the apparatus and to reduce the vibration characteristics of the vehicle. A torque converter with a direct-coupled clutch that can increase the direct-coupled area of the direct-coupled clutch to a lower vehicle speed range without deteriorating the fuel consumption and improve the durability of accessories is proposed.

As shown in the simplified model of FIG. 10, this torque converter is obtained by adding a dynamic damper (sub-vibration system) d to a conventional vibration transmission system (main vibration system). In FIG. 10, I0 represents the moment of inertia of the dynamic damper d, and K0 represents the torsional rigidity of the dynamic damper d. According to this vibration transmission system, the torsional stiffness K0 and the inertia moment I0 of the dynamic damper d act on the secondary inertia moment I2 of the automatic transmission, thereby changing the secondary inertia moment I2 of the automatic transmission. It is possible to reduce the level.

In the torque converter according to the above-mentioned application, the turbine which does not contribute to the torque transmission when the direct coupling clutch is in the operating state is elastically supported by the member which contributes to the torque transmission via an elastic body. In addition, the turbine and the elastic body function as a dynamic damper without increasing the weight. That is,
A turbine in an existing torque converter is used as a mass of a dynamic damper, that is, a member for generating a moment of inertia, and the torsional rigidity of the dynamic damper is adjusted by the elastic body.

[0015] However, the torque converter proposed here has a point to be further improved.

That is, by adding the dynamic damper function, it was possible to suppress the vibration in the frequency range originally aimed at, but the vibration characteristics in another frequency range (especially on the high rotation side) deteriorated. there were.

As a countermeasure, it is conceivable to make the spring constant and inertia (mass) of the dynamic damper variable by hydraulic pressure or electromagnetic force. However, the structure becomes complicated and the number of parts may increase. It is difficult to realize while keeping costs down.

The present invention has been made in view of the above circumstances, and a fluid transmission with a direct coupling clutch which can effectively suppress newly generated vibration by adding a dynamic damper function by a simple structural change. It is an object to provide a device.

[0019]

SUMMARY OF THE INVENTION The present invention relates to a fluid transmission device with a direct coupling clutch having a damper mechanism, which transmits torque when the direct coupling clutch is in an operating state on the downstream side of the power transmission path from the damper mechanism. A mass body is connected to a contributing member via an elastic body so as to constitute a dynamic damper, and the elastic body is elastically deformed only when a torque exceeds a predetermined value, and transmits a torque to the torque transmission in a preloaded state. The above object has been achieved by being assembled between the contributing member and the mass body.

In this fluid transmission device (including not only a torque converter with torque amplification but also a mere fluid coupling), the member contributing to the torque transmission and the mass body tend to rotate relative to each other, so that the torsional torque between the two exceeds a predetermined value. The elastic body starts elastically deforming only when it is pressed. Therefore, when the torque is large, the mass body is softly and elastically supported by the members contributing to the torque transmission, and the dynamic damper function is exhibited. On the other hand, when the torsional torque is less than the predetermined value, the elastic body does not elastically deform and functions almost or completely as a rigid body. Therefore, when the torque is small, the dynamic damper function is not exhibited.

That is, in a state where the exciting force to the dynamic damper (for example, the rotational fluctuation level of the automatic transmission main body due to the explosion vibration of the engine) is large (the torque fluctuation is large),
When the elastic body has low spring characteristics (small spring constant = large elasticity) and the excitation force is small (torque fluctuation is small), the elastic body has high spring characteristics (large spring constant = small elasticity).

Generally, in an engine, as shown in FIG. 8, when the number of rotations increases, the rotation fluctuation level (excitation torque) increases.
When the number of rotations decreases, the rotation fluctuation level (excitation torque) tends to increase. This tendency is directly transmitted to the torque converter (fluid transmission) of the automatic transmission. Therefore, the elastic body has such a property that the equivalent spring constant decreases on the low rotation side where the torsional torque is large and the equivalent spring constant increases on the high rotation side where the torsional torque is small.

On the other hand, when a dynamic damper is added as described above, the effect of suppressing vibration on the low rotation side can generally be expected, but on the other hand, the vibration deteriorates on the high rotation side. Therefore, the spring characteristics of the above-mentioned elastic body exhibit an effect. That is, on the low rotation speed side, the dynamic damper function is exerted to bring out the vibration suppressing effect. On the high rotation side, the dynamic damper function is deliberately invalidated to prevent the deterioration of the vibration characteristics. This makes it possible to suppress vibration in a wide frequency range. Also, this effect,
Since it can be realized with a very simple configuration of applying a preload to the elastic body, the cost can be reduced.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a torque converter according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the arrow II in FIG. 1, and FIGS. 3 to 5 are sectional views taken along the arrows in FIG. In the following, mainly FIG. 1 will be used, and details will be described with reference to FIGS.

The torque converter 2 mainly includes a pump 4, a turbine 6, a stator 8, and a direct coupling clutch 10.
It is composed of

The turbine 6 includes a turbine runner 6A and a turbine hub 6B, and the turbine runner 6A and the turbine hub 6B are joined together by rivets 7 on the same circumference and integrated. An output hub 32 that transmits the output of the torque converter 2 to an output shaft (transmission input shaft) 5 is provided on the inner peripheral side of the turbine hub 6B. The output hub 32 and the turbine hub 6B are separated from each other,
It is assembled so that it can rotate relatively.

The lock-up piston 12 of the direct coupling clutch 10 is connected to a front cover 14 of the torque converter 2.
Has a lining (friction plate) 16 which comes into contact with the inner surface of the. A drive plate 20 is integrally attached to the lock-up piston 12 by a rivet 18. An intermediate plate 22 is provided between the lock-up piston 12 and the drive plate 20. The intermediate plate 22 has a long hole 24 in which the rivet 18 is loosely fitted.

The drive plate 20 transmits torque to the driven plate 28 via the outer damper spring 26 and the intermediate plate 22. The driven plate 28 is fixed to the disk wall 32 of the output hub 32 by the rivet 30.
a.

The lock-up piston 12 is slidably fitted to a cylindrical portion 38 provided on the outer periphery of the disk wall 32a of the output hub 32 via a seal 40 by an inner cylindrical portion 36.

A turbine 6 is provided on the outer periphery of the turbine hub 6B.
The first and second engagement projections 44 and 45 (FIG. 1) projecting in a direction (axial direction of the torque
(Only the first engaging projections 44 are shown) are provided at intervals in the circumferential direction.

As shown in FIG. 2, the first engaging projections 44 and the second engaging projections 45 are alternately arranged at 90 ° intervals (in this embodiment) on the same circumference. The two first engagement projections 44 are provided symmetrically with respect to the center position (neutral line L shown in the drawing) of the arrangement location. The pair of first engaging projections 44, 44 have their ends facing each other at a constant interval in the circumferential direction, and an inner damper spring 46 described later is inserted between the facing ends. It is supposed to.

Returning to FIG. 1, a plurality of spring holding portions 50 are provided at a radially intermediate portion of the driven plate 28 at intervals in the circumferential direction, and a dynamic damper is provided on each spring holding portion 50. The constituent inner damper spring (elastic body) 46 is held. In this case, the inner damper spring 46 is a compression coil spring. Note that a material such as a rubber material may be used.

As shown in FIG. 2, both ends 50a of the spring holding portion 50 are arranged in the circumferential direction of the driven plate 28.
It is formed as a limited length window having 50a. As shown in FIGS. 3 to 5, the driven plate 28 has a cover 2 attached to the driven plate main body 28 a.
8b is attached with a rivet 29, and a spring holding portion 50 is formed between the driven plate main body 28a and the cover 28b. Both end walls 50a and 50b of the spring holding portion 50 are driven plate body 28a.
And a notch edge formed in the cover 28b.

As shown in FIG. 2, the driven plate 28 is formed with a substantially rectangular long hole 50b which is long in the circumferential direction and adjacent to the spring holding portion 50. Slot 5
0b are provided so as to face each other with the spring holding portion 50 interposed therebetween.
It continues in the space of 0.

An inner damper spring 46 made of a compression coil spring is fitted in the spring holding portion 50. In this case, the inner damper spring 46 is fitted in a compressed state in which both ends are received on both end walls 50a of the spring holding portion 50, and a predetermined preload is applied. The first engaging projections 44 formed on the turbine hub 6B are inserted into the long holes 50b on both sides of the inner damper spring 46 so as to sandwich the inner damper spring 46. As a result, the turbine hub 6B is elastically connected to the driven plate 28 via the inner damper spring 46.

The repulsive force of the inner damper spring 46 is almost equally received by both end walls 50a of the spring holding portion 50 and the end of the first engaging projection 44 in the neutral position. To be incorporated.

As shown in FIGS. 2 and 5, a stopper mechanism is provided between the turbine hub 6B and the driven plate 28 to lock the turbine hub 6B and the driven plate 28 so that the turbine hub 6B and the driven plate 28 do not rotate relative to each other by a predetermined angle or more. 60 are provided. The stopper mechanism 160 functions to prevent the inner damper spring 46 from adhering between the lines, and is provided between the second engagement projection 45 protruding from the turbine hub 6B and the driven plate 28. It is made up of a long hole 63 formed. The long hole 63 is formed to have a length that regulates the moving range of the second engagement projection 45.
The second engagement projection 45 abuts on the end of the turbine hub 6B and the driven plate 28 to restrict the relative rotation range.

Next, the operation will be described.

First, the operation when the direct-coupled clutch 10 is operating (during direct-coupled traveling, that is, when the torque converter is not operating) will be described.

When the direct coupling clutch operates, the lock-up piston 12 moves to the right in FIG. 1 by the action of hydraulic pressure (by a known configuration) and is pressed against the front cover 14. The front cover 14 is driven by an engine (not shown). Therefore, torque from the engine is directly transmitted to the lock-up piston 12 via the lining 16.

The drive plate 20 integrated with the lock-up piston 12 includes the outer damper spring 2
Press one end of 6. For this reason, the outer damper spring 26
Will push the intermediate plate 22. The torque transmitted to the intermediate plate 22 is
8, is transmitted to an output hub 32 which is an output member.

Here, the outer damper spring 26 corresponds to the torsional rigidity K1 on the primary side (upstream of the damper mechanism) of the engine and the automatic transmission in FIG. The members after the intermediate plate 22 correspond to the inertia moment I2 on the secondary side of the automatic transmission (downstream of the damper mechanism).

On the other hand, the turbine 6 is connected to the driven plate 28 on the secondary side of the automatic transmission via the inner damper spring 46 as described above. Therefore, the turbine 6 as a member that does not contribute to torque transmission when the direct coupling clutch 10 is in the operating state is connected to the driven plate 28 as a member that contributes to torque transmission via the inner damper spring 46 as an elastic body. Thus, the turbine 6 functions as a member that generates the inertia moment I0 of the dynamic damper d in FIG. 10, and the inner damper spring 46 functions as a member corresponding to the torsional rigidity K0 of the dynamic damper d.

In this case, the inner damper spring 46
In a compressed state to which a predetermined preload is applied, the spring holding portion 5
0, the relationship between the torsion angle and the torsion torque as shown in FIG. 6 is established between the turbine hub 6A that is about to rotate relatively and the driven plate 28. In FIG. 6, a dotted line indicates a case without preload, and a solid line indicates a case with preload.

As can be seen from this figure, the inner damper spring 46 starts elastically deforming only when the torsional torque between the driven plate 28 and the turbine hub 6B exceeds the predetermined value a1. That is, the first engagement projection 4 shown in FIG.
Even if 4 presses the inner damper spring 46, the inner damper spring 44 is pressed against the end wall 50a of the spring holding portion 50 by the preload, so that the inner damper spring 44 is pressed until a force (torsional torque) of a value a1 or more is applied. The damper spring 46 does not start to deform. Therefore, when the torque is within the predetermined value a1, there is no twist angle, that is, the inner damper spring 46 behaves like a rigid body.

Although the torsional torque is larger than a1,
When the value is relatively small a2, the twist angle becomes a small value b2. In this case, the equivalent spring constant becomes large as shown by the two-dot chain line. When the torsion torque is a large value a3, the torsion angle is b3, and the equivalent spring constant has a lower slope than when the torsion torque is small, as indicated by the one-dot chain line.

FIG. 7 shows the fluctuation characteristics of a drive system using this torque converter.

In FIG. 7, A shows a case without a dynamic damper, B shows a case with a dynamic damper and no preload, and C shows a case with a dynamic damper and a preload. As can be seen from this figure, the rotational fluctuation level of the automatic transmission is reduced in the region a in the case of B with the dynamic damper having the spring characteristic without the preload, as compared with the case of A without the dynamic damper. In b, it gets worse. That is, the resonance point is specified as one point, and the vibration suppression effect there is great, but a new resonance region b is generated.

On the other hand, in the case of C provided with a dynamic damper having a spring characteristic with preload, it is reduced in the region c and does not deteriorate in the region d.

In the areas a and c, C has a smaller reduction amount of the fluctuation level than B, but the permissible level in the lock-up execution area F.

Therefore, as can be seen from the characteristic C in FIG. 7, according to the torque converter of the present embodiment, the vibration damping effect due to the addition of the dynamic damper can be extended to a wide frequency (engine speed) region. it can.

In this embodiment, the dynamic damper is formed by using the existing turbine as the mass body, so that the dynamic damper function can be provided without increasing the weight and storage space. Therefore, it is possible to lower the directly-connected traveling range (without deteriorating the vibration characteristics) to a lower speed side, thereby improving fuel efficiency.

Next, the operation when the direct coupling clutch is not operated (during the running of the torque converter) will be described.

When the engine drives the front cover 14, the pump 4 integrated with the front cover 14 is driven. When the pump 4 is driven, a fluid flow is generated, which drives the turbine 6. At this time, the stator 8 adjusts the direction of the fluid flowing from the turbine 6 to the pump 4.

When the turbine 6 is driven, the first engagement projection 44 of the turbine hub 6B is moved to the inside damper spring 46.
, The torque of the turbine 6 is transmitted to the driven plate 28 via the inner damper spring 46. The torque that cannot be received by the inner damper spring 46 is transmitted via the stopper mechanism 60. The driven plate 28 is fixed to the output hub 32, and torque is transmitted from the output hub 32 to an output shaft (not shown).

In the above embodiment, a turbine which does not contribute to torque transmission at lock-up is used as the mass body (inertia) of the dynamic damper. However, a stator may be used instead, or both may be used. You may.
Further, a mass body constituting the dynamic damper may be newly provided separately from the existing members.

[0058]

As described above, according to the present invention,
The substantial spring constant of the dynamic damper can be reduced on the low rotation side where a large rotation fluctuation occurs, and the substantial spring constant of the dynamic damper can be increased on the high rotation side where only a small rotation fluctuation occurs. Therefore, the resonance frequency of the dynamic damper can be reduced on the low rotation side and the resonance frequency of the dynamic damper can be increased on the high rotation side, thereby reducing the rotation fluctuation level of the automatic transmission in a wide frequency range. it can. In addition, since this effect can be realized with a very simple configuration in which a preload is applied to the elastic body, cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing a torque converter according to an embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrow II in FIG.

FIG. 3 is a sectional view taken along the arrow III in FIG. 2;

4 is a sectional view taken along the arrow IV in FIG.

FIG. 5 is a sectional view taken along the arrow V in FIG. 2;

FIG. 6 shows a relationship between a torsional torque and a torsion angle generated between a turbine hub and a driven plate connected via an inner damper spring in the torque converter according to the embodiment of the present invention (substantial spring characteristics by the inner damper spring). Figure showing

FIG. 7 is a characteristic diagram showing characteristics of a vibration transmission system using the torque converter according to the present invention in comparison with others.

FIG. 8 is a characteristic diagram showing a relationship between an engine speed and rotation fluctuation.

FIG. 9 is a schematic diagram of a simplified model showing a conventional vibration transmission system.

FIG. 10 is a schematic diagram of a simplified model showing a vibration transmission system of a previously unknown prior application.

[Explanation of symbols]

 2 Torque converter 6 Turbine (mass body) 10 Direct coupling clutch 26 Outer damper spring (damper mechanism) 28 Driven plate (member that contributes to torque transmission) 44 First engagement projection 46 Inner damper spring (Elastic body) 50: Spring holding part 50a: Both end walls

Claims (1)

[Claims] 1. A fluid transmission device with a direct coupling clutch having a damper mechanism, wherein a dynamic damper is provided on a member downstream of the damper mechanism in a power transmission path and contributing to torque transmission when the direct coupling clutch is in an operating state. A mass body is connected via an elastic body so as to constitute, and, between the member and the mass body that contribute to the torque transmission in a pre-loaded state so that the elastic body is elastically deformed only when the torque exceeds a predetermined value. A fluid transmission device with a direct coupling clutch, which is assembled.