JP2797691B2 - Damper mechanism of fluid transmission with lock-up clutch - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper mechanism provided in a fluid transmission with a lock-up clutch.

2. Description of the Related Art As is well known, a fluid transmission device generates a fluid flow by an input driving force, and the fluid flow acts on an output member to rotate the member, thereby transmitting power. It is. In this type of device, there is an inconvenience that power loss occurs because there is an unavoidable rotational speed difference between the input side member and the output side member. Therefore, for example, a torque converter for a vehicle is provided with a lock-up clutch in order to prevent deterioration of fuel efficiency due to power loss.

A general lock-up clutch in a vehicle torque converter is disposed between an inner surface of a front cover and a turbine runner, and by draining fluid from between the front cover and the lock-up clutch, or on a turbine runner side. By increasing the oil pressure, the lock-up clutch is pressed against the front cover, whereby the lock-up clutch is engaged to directly transmit torque from the front cover as an input element to the output shaft as an output element.

Therefore, when the lock-up clutch is engaged, the input element and the output element are mechanically directly connected to each other, so that no power loss occurs, but vibrations caused by torque fluctuation are transmitted between these elements. Will be done.
Therefore, conventionally, a damper mechanism mainly comprising a damper spring is incorporated in the lock-up clutch to reduce vibration. This damper mechanism must first have a capacity to absorb the expected maximum input torque, but if a damper spring with a large spring constant is used to withstand a large torque, the vibration will be sufficiently reduced. This makes it impossible to do so, and also causes the problem that the muffled sound is increased. As described above, the damper mechanism is required to increase the spring constant to some extent in terms of strength, and conversely, to reduce the vibration, it is required to reduce the spring constant. Conventionally, to satisfy these conflicting demands,
2. Description of the Related Art A damper mechanism is configured using a plurality of types of damper springs having different spring constants.

One example is described in JP-A-61-252964, which is briefly described as follows.

That is, in FIGS. 15 and 16, a pump impeller 3, a turbine runner 4 disposed opposite to the pump impeller 3, and a pump impeller 3 and a turbine runner 4 are provided in a housing 2 of the torque converter 1. A stator 5 arranged between the front cover 2a and a lock-up clutch 6 arranged between the front cover 2a and the turbine runner 4 is provided.

The lock-up clutch 6 includes a disk-shaped drive-side member 7 that is engaged with and released from the inner surface of the front cover 2a, and a disk-shaped driven-side member 9 that is disposed to face the drive-side member 7. And

The driven side member 9 includes a first plate 9a connected to the outer peripheral portion of the driving side member 7, a second plate 9b connected to the first plate 9a via a first damper spring 10, The second damper spring 11 is attached to the second plate 9b.
The third plate 9c is fixed together with the turbine runner 4 to a hub 4a that is spline-fitted to the output shaft 8 of the torque converter 1 via a third plate 9c. The first damper spring 10 and the second damper spring 11 have different spring constants. For example, the spring constant of the first damper spring 10 is set to a value smaller than the spring constant of the second damper spring 11. I have.

Therefore, in the conventional torque converter 1 described above, if the input torque in the lock-up state is small, the first damper spring 10 expands and contracts to absorb torque fluctuations, and if a large torque is input, the spring constant is large. The second damper spring 11 is compressed to absorb the torque. That is, when the torque is low, the torsion angle of the lock-up clutch 6 with respect to the predetermined torque increases, and when the torque is high, the torsion angle of the lock-up clutch 6 with respect to the predetermined torque decreases, and the spring characteristics change in two stages. As a result, the generation of the muffled sound caused by the fluctuation of the engine torque in the normal running state is prevented by the action of the first damper spring 10 having a small spring constant, and the large damping torque is temporarily input. The second damper spring 11 having a large spring constant acts to prevent damage.

Problems to be Solved by the Invention A damper mechanism using a damper spring having a different spring constant has an advantage of being able to withstand a large impact torque, so that a large torque is relatively frequently input from a tire like an off-road vehicle. This is a particularly effective mechanism for vehicles that may be used. However, since the spring constant greatly changes at a predetermined twist angle, there are the following inconveniences.

That is, when an impact torque is input, first, a damper spring having a small spring constant is rapidly and greatly compressed,
Thereafter, when the torsion angle becomes an angle at which the spring constant changes, abrupt and large torque is transmitted through the damper mechanism at this point, so that the torque of the output shaft of the vehicle rapidly changes. This is perceived by the occupant as an impact generated when the drive mechanism has backlash, and may cause a reduction in ride comfort and vehicle stability.

Further, in the above-described conventional configuration, the spring constant changes abruptly and greatly at a predetermined torsion angle. For example, a large impact torque is input from a tire while traveling on uneven terrain, and as a result, a damper having a large spring constant is obtained. When the spring is also compressed, and thereafter the input of torque from the tire is stopped, the energy stored in the damper spring having a large spring constant is determined by the change point of the spring constant, that is, the torsion angle is the angle at which the spring constant changes. It is released rapidly until This is a situation similar to the case where the input torque greatly changes. Since this torque fluctuation is reduced by the damper spring having a small spring constant, there is a possibility that a so-called shear is generated in which the torsion angle is large and changes slowly and repeatedly. There is.

As described above, in the above torque converter, the spring characteristic of the damper mechanism of the lock-up clutch changes abruptly at a predetermined torsion angle.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a damper mechanism that can effectively prevent a shearing generated near a predetermined torsion angle at which a spring characteristic changes.

Means for Solving the Problems In order to achieve the above object, the present invention selectively relates to an input element integrally connected to a pump impeller, an output element integrally connected to a turbine runner, and the input element. A lock-up clutch that transmits power from the input element to the output element by coupling the damper spring, and a damper spring that is compressed in accordance with a torsional torque applied to the lock-up clutch. In a damper mechanism of a fluid transmission with a lock-up clutch in which a spring characteristic changes at a torsion angle, a resistance force against a torsion action of compressing the damper spring is changed within a predetermined angle range near the torsion angle at which the spring characteristic changes. The resistance in an angle range smaller than the predetermined angle range, and The present invention is characterized in that a viscous damping mechanism is provided which becomes larger than a resistance force in an angle range of an angle larger than the angle range.

Effect In the fluid transmission according to the present invention, by engaging the lock-up clutch, a torsional torque acts on the lock-up clutch, and the damper spring is compressed according to the magnitude of the torque. When the torsion angle associated with the compression of the damper spring reaches a predetermined angle, the spring characteristic changes, and at a larger angle, the ratio of the change in the torsion angle to the change in the input torque decreases to a smaller angle. Different from the area. Assuming that the torsion angle at which the spring characteristic changes is referred to as a change point, the damper mechanism of the present invention has a predetermined angle range including a state immediately before the torsion angle reaches the change point or at the same time as or immediately after the torsion angle reaches the change point. Is greater than the resistance in the angle range smaller than the predetermined angle range and the resistance in the angle range larger than the predetermined angle range. This also occurs when the input torque decreases and the energy stored in the damper spring is released after the torsion angle exceeds the change point, and the torsion angle decreases beyond the change point.

Therefore, in the present invention, by causing the viscous damping action to occur immediately before the change point, the change point does not significantly occur as a change in the output shaft torque or as a behavior of the vehicle. Further, the viscous damping action occurs before or after the change point, thereby preventing shearing caused by a change in the spring constant, in other words, shaking when a large impact torque is input.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 14.

First, a first embodiment will be described with reference to FIGS. The torque converter 21 shown in FIG. 1 has substantially the same structure as a conventional torque converter except for a lock-up clutch, a damper mechanism, and a viscous damping mechanism, and has an output shaft (not shown) of an engine. )
Housing 23 that connects drive plate 22 mounted on
Is constituted by a front cover 23a and a case of the pump impeller 24.In the housing 23, a turbine runner 25 to which torque is transmitted from the pump impeller 24 via AT oil is disposed so as to face the pump impeller 24.
Further, a stator 26 for changing the direction of the flow of the AT oil from the turbine runner 25 to the pump impeller 24 is disposed between the turbine runner 25 and the pump impeller 24. Further, the turbine runner 25 is attached to a hub 27a spline-fitted to the output shaft 27, and an outer peripheral portion of the hub 27a has a substantially disk-shaped cover located between the turbine runner 25 and the front cover 23a. The drive side member 28 is spline-fitted so that it can move in the axial direction. Further, between the driven side member 28 and the front cover 23a, the driving side member 2 is provided.
9 are located. As shown in the cross section in FIG. 1, the drive side member 29 has a disk-shaped portion facing the driven side member 28 and a cylindrical portion extending in the axial direction on the outer peripheral portion. The cylindrical portion is fitted to the driven member 28.

The drive-side member 29 will be further described. As shown in FIG. 2, a surface of the drive-side member 29 facing the driven-side member 28 has six concentric annular ribs 29a, 29b,. 29
f are formed so as to protrude at predetermined intervals in order from the outer peripheral side, and between these annular ribs 29a, 29b,.
That is, among the five valleys, the stopper valleys 30 for the damper spring are provided at three valleys except for between the annular ribs 29b and 29c and between the annular ribs 29d and 29e at positions where the circumference is divided into four equal parts and concentric circles respectively. Are formed so as to protrude in an arc shape that forms part of. In other words, an arc-shaped notch is formed by cutting off a part of the annular rib over a predetermined length so that the stopper rib 30 remains. Note that the stopper rib 30 in the valleys of the stopper rib 30 and the intermediate portion of the outermost valleys, is set to a length that a central angle shown in FIG. 2 is theta _a.

The cutout accommodates a damper spring described below. That is, the first damper springs 31a, 31b, and 31c having a smaller spring constant than the damper springs used for this type of conventional application are provided at the three valleys where the stopper ribs 30 are formed, respectively. To 8
And a total of 24 are accommodated. The installation state is specifically shown in FIG. 2, and the circumferentially adjacent stopper ribs are provided.
Between each other, that is, in each notch, a pair of first
The damper springs 31a, 31b, 31c are fitted with the spacer block 32 interposed therebetween. The spacer block 32 is movable in the circumferential direction, and is provided to reduce the length of each of the damper springs 31a to 31c to prevent buckling.

Further, in the valley between the annular ribs 29b and 29c among the valleys where the stopper rib 30 is not provided, at a position where the circumference is divided into four equal parts and a position rotated 15 degrees in the circumferential direction from the position of the stopper rib 30, Four pairs of arc-shaped viscous damping ribs 33 are formed at regular intervals. As shown in FIG. 2, the viscous damping ribs 33 are a set of two ribs having a central angle of θb, and a pair of the viscous damping ribs 33 is provided.
Between them, a second damper spring 36a is fitted. Note that the second damper spring 36a may have the same or different spring constant as the first damper springs 31a, 31c.

On the other hand, in the driven-side member 28, at the respective positions on the surface facing the driving-side member 29 that divide the circumference into four equal parts, as shown in FIG. Are formed. The pushing rib 34 is used when the driving member 29 and the driven member 28 rotate relatively.
Damper springs 31a, 31c together with the stopper rib 30
The ribs 30 and 29a are formed so as to fit into the ribs 30, 29a, to 29f with a slight gap between the stopper rib 30 and the annular rib 29a on the drive side member 29 side. .

Further, four pairs of damping ribs 35 are formed on the driven side member 28. These damping ribs 35 correspond to the driving-side members described above.
A counterpart to the viscous damping rib 33 which is formed in 29, are formed to Article 3 at positions viscous damping ribs 33 and projection fitting as arcuate rib comprising a pair Toshikatsu central angle theta _b I have. The circumferential position is a position rotated by about 15 degrees from the pushing rib 34 as shown in FIG. 3, and therefore, in the initial state where the driving side member 29 and the driven side member 28 are assembled. The viscous damping rib 33 and the damping rib 35 are located in the circumferential direction and are not fitted to each other. A second damper spring 36b is fitted between the pair of damping ribs 35.

FIG. 4 shows these ribs 29a, 29f, 30, 33, 34, 35
3 shows a fitting state of

Further, sliding portions of the inner and outer peripheries of the driven side member 28 and the driving side member 29 are sealed by X-shaped seals, and the driven side member 28 and the driving side member sealed by these X-shaped seals.
A high-viscosity oil such as silicone oil or the like is sealed in a hollow portion between the chamber 29 and an appropriate amount of air, and a variable-capacity viscous damping mechanism 37 is formed therein.

Further, a friction material 40 is adhered to the inside of the front cover 23a, and the drive side member 29 is pressed against the friction material 40, so that the input torque increases the drive side member 29 and the damper springs 31a, 31c, 31c, 36a, The power is transmitted to the output shaft 27 via the driving member 36b and the driven member 28. That is, the lock-up clutch 39 is formed here.

Next, the operation of the torque converter 21 configured as described above will be described.

In a state where the running state of the vehicle has not reached the lock-up area, the pressure between the front cover 23a and the driving side member 29 is increased, and the driving side member 29 is removed from the friction material 40 adhered to the inner surface of the front cover 23a. In this state, the lock-up clutch 39 is released, and in this state, torque is transmitted from the pump impeller 24 integral with the housing 23 to the turbine runner 25 via AT oil, and furthermore, torque is transmitted to the output shaft 27. Is transmitted. As described above, at the time of low speed, the torque is transmitted via the fluid, so that the vibration due to the torque fluctuation is cut by the slip of the torque converter 21.

When, for example, the vehicle speed increases and the running state of the vehicle reaches the lock-up region, the hydraulic pressure Pa on the turbine runner 25 side with respect to the hydraulic pressure between the front cover 23a and the drive side member 29.
Is relatively increased, and as a result, the driven side member 28 moves to the front cover 23a side (the left side in FIG. 1).
Since a high-viscosity oil is enclosed between the driven-side member 28 and the driving-side member 29 together with an appropriate amount of air, the driving-side member 29 moves to the high-viscosity oil with the movement of the driven-side member 28. It is pushed toward the front cover 23a through the air filled therein, and is pushed against the friction material 40. That is, the lock-up clutch 39 is engaged. In this case, the driving member 29 is
When the contact with the high-viscosity oil has begun, the engagement pressure of the lock-up clutch 39 is low. When the air is compressed by approaching the member 29, the pressure between the driving-side member 29 and the driven-side member 28 gradually increases, and the engagement pressure of the lock-up clutch 39 also increases accordingly. That is, the air sealed together with the high-viscosity oil performs a buffering action, and the engagement pressure of the lock-up clutch 39 gradually increases.

In a state where the lock-up clutch 39 is engaged, most of the input torque is transmitted to the output shaft 27 via the driving side member 29 and the driven side member 28, so that these two members 29, 28 A torsional torque acts between them.
Therefore, if the input torque is equal to or less than the predetermined torque, the first damper springs 31a, 31c having a small spring constant are compressed, and a relative torsion occurs between the driving side member 29 and the driven side member 28. Also, if the input torque increases further,
The second damper springs 36a and 36b are also compressed to prevent overload. Therefore, if the relative torsion angle between the driving side member 29 and the driven side member 28 (hereinafter, simply referred to as torsion angle) is equal to or smaller than a predetermined value, the vibration is reduced by the first damper springs 31a to 31c. If the torsion angle is equal to or larger than a predetermined value, the first and second damper springs 31a, 31c, 36c
The input torque is absorbed by a and 36b, so that the spring characteristic changes in two steps.

The operation of these damper springs 31a, 31c, 36a, 36b will be described with reference to the schematic diagrams of FIGS.
These figures are development views showing the above-described ribs linearly extended, and FIG. 5 (A) shows the lock-up clutch 39.
Shows a state in which no torsional torque is applied. In this state, the stopper rib 30 of the driving side member 29 and the pushing rib 34 of the driven side member 28 are completely fitted, that is, overlapped in the radial direction, and the wrap length 1 is the longest. Has become. The viscous damping rib 33 and the damping rib 35 are separated at the maximum interval, which is represented by θ _c shown as the value of the central angle in FIGS. 4 and 5A, that is, the opening angle θ in the assembled state. _Expressed by _c . Then, no compressive force is applied to any of the damper springs 31a to 31c, 36a, 36b.

When torque is input to the torque converter 21, a torsional torque acts on the lock-up clutch 39, and the drive-side member
The 29 and the driven side member 28 are in a twisted state. Figure 5 (B) shows a state in which the twist angle is the lock-up clutch 39 until the slightly larger angle than the center angle theta _a stopper ribs 30 is twisted, in this state, the stopper rib 30 and the pushing rib 34 Are relatively moved in the circumferential direction to cancel the engagement, and as a result, the first damper spring 31a,
31c are compressed by the stopper rib 30 and the pushing rib 34. For even higher torsion angles, these ribs
The lap length of 30,34 becomes "0". On the other hand, FIG. 5 (B)
In the state of, the torsional angle is reduced by viscous damping rib 33 and damping rib 35
Since not reached the initial opening angle theta _c between these ribs 33 and 35 Izu overlap in the radial direction, and the second damper springs 36a, the initial assembly time than the compressive force acting on the 36b I haven't.

By the input torque is larger, twist angle becomes equal to or larger than the initial opening angle theta _c between the attenuation rib 35 and the viscous damping ribs 33, these ribs 33 and 35 begins to fit. Fig. 5 (C)
Shows the state, the viscous damping rib 33 and the damping rib 35
And between the two, the wrap length l2 gradually increases. At this point, the second damper spring
36a and 36b have not yet been compressed beyond the initial state.

When the torsion angle is equal to or greater than the angle (θ _c + θ _b ) obtained by adding the initial opening angle θ _c between the viscous damping rib 33 and the damping rib 35 and the central angle θ _b with respect to the length of the ribs 33 and 35,
Viscous damping rib 33 and damping rib 35 inserted between each
The second damper spring 36a,
36b is pinched and compressed by these ribs 33,35. This state is shown in FIG.
The lap length l2 of 3,35 gradually decreases. The ribs 33 and 35 come out of each other when the twist angle is further increased, so that the wrap length is "0".

As described above, the first damper springs 31a and 31c are compressed until the torsion angle exceeds (θ _c + θ _b ),
With a larger torsion angle, the first damper springs 31a, 31
Since both c and the second damper springs 36a and 36b are compressed, the spring characteristics of the above damper mechanism change in two steps. Such a characteristic can be represented by a characteristic diagram in which the torsion angle is plotted on the horizontal axis and the torque is plotted on the vertical axis, as shown in FIG. 6 (A), where the torsion angle is (θ _c + θ _b ). It is represented by a bent line. The angle of (θ _c + θ _b ) is hereinafter referred to as a change point.

Therefore, the first damper springs 31a, 31c are set so that the torsion angle θ based on the average maximum torque of the engine input to the torque converter 21 is slightly smaller than the change point.
If the spring constant of is set, the fluctuation of the input torque from the engine is reduced by the first damper prim 31a,
Since 31c expands and contracts and absorbs, generation of muffled noise caused by fluctuations in engine torque is prevented.

Also, when a large impact torque exceeding the average maximum torque of the engine is input from the tires when traveling on a rough road, the second damper springs 36a and 36b having a large spring constant also start to be compressed at the time when they are twisted until exceeding the change point. . Therefore, a large impact torque is generated by two types of damper springs 31a,
Since it is absorbed by 3131c, 36a, and 36b, the torsion angle does not become excessive, and damage to the damper mechanism is prevented.

By the way, arc-shaped ribs such as the stopper rib 30 and the viscous damping rib 33 described above are used for damper springs 31a, 31c, 36a, 36.
In addition to pressing b to compress, it also acts to generate viscous torque. Hereinafter, the viscous damping action will be described.

The above-mentioned arc-shaped ribs generate a viscous torque by shearing the highly viscous oil filled between them,
The magnitude of the viscous torque is inversely proportional to the gaps h1, h2 between the ribs 30, 33, 34, 35, and proportional to the wrap length 1, l2 and the speed difference in the shear direction.

Therefore, in the state shown in FIG. 5 (A) where the twist angle is “0 °”, the wrap length 1 between the stopper rib 30 and the pushing rib 34 is maximum, and the viscosity generated by these ribs 30 and 34 is large. If the rate of change of the torsion angle is constant, the torque Ta becomes maximum when the torsion angle is “0 °”. The length of these ribs 30 and 34, the length of the central angle theta _a,
Since the lap is performed during this time, when the twist angle changes from “0 °” in the plus direction and the minus direction, the viscous torque Ta
There becomes gradually smaller in a range of angles theta _a.

In the condition shown in FIG. 5 where the twist angle exceeds θ _a (B), because any of arcuate ribs nor wraps each other, there is no viscous torque due to the arc-shaped ribs.

This state continues until exceeding _c twist angle theta, since the subsequent attenuation rib 35 and the viscous damping ribs 33 as shown in FIG. 5 (C) starts to overlap in the radial direction, these ribs 33 and 35 As a result, a viscous torque Tb starts to be generated. The wrap length l2 of these ribs 33, 35 is the longest at the point of change,
After that, the lap length gradually decreases. The length of the ribs 33 and 35 minutes from the change point, further twisting, i.e. the twisting angle between the transition points theta _b, lap length l2 is,
It becomes “0” and the viscous torque Tb also becomes “0”. That viscosity torque due the viscous damping ribs 33 and the damping ribs 35 is the largest at the change point, gradually decreases within a range of ± theta _b across it.

Since the relative speed between the driving side member 29 and the driven side member 28 decreases as the torsion angle increases, the viscous damping rib 33 and the damping rib 35 are calculated based on the viscous torque Ta generated by the stopper rib 33 and the pushing rib 34. And the viscous torque Tb generated is smaller.

The above viscosity characteristics are shown in a characteristic diagram as shown in FIG. 6 (B), and ± around a point where the torsion angle is “0 °”.
viscous torque Ta in a range of ± theta _b centered on the range and change point of theta _a, Tb occurs, each of the torque Ta, Tb is smaller as the twist angle away from the point and a change point of "0 °" Become. FIG. 6 (B) assumes that the rate of change of the torsion angle in each range is constant.

FIG. 6 (C) shows the combined spring characteristics and viscous damping characteristics described above. As is known from this figure, in the torque converter 21 shown in FIG. 1, since the viscous damping action occurs in _a range of ± θa around the point where the torsion angle is “0 °”, it is caused by the fluctuation of the engine torque. Although the spring constants of the first damper springs 31a to 31c for reducing vibration are small, and as a result, the shear torque is likely to occur, the viscous torque generated at the stopper rib 30 and the pushing rib 34 is reduced by the drive side member 29 and the driven side. It works to suppress the relative twisting action with the member 28, and effectively prevents the shearing due to the small spring constant.

On the other hand, when a large impact torque is input such that the torsion angle becomes larger than the change point, the first torque damper springs 31a, 31c and the second Although the damper springs 36a and 36b extend and emit energy, the second damper springs 36a and 36b are springs having a large spring constant.
When a large torsion torque is applied by the second damper springs 36a and 36b and the torsion angle becomes smaller than the change point, the torsion torque disappears. This second damper spring 36
The temporary large torque due to the elastic energy of the a and 36b is a phenomenon similar to that the input torque to the torque converter 21 temporarily increases. Therefore, the second damper springs 36a and 36b having a large spring constant Is released, there is a possibility that a shearing force in which the torsion angle increases / decreases around the changing point may occur. However the torque converter 21 described above, as shown in FIG. 6 (C), since the viscous damping effect in a range of ± theta _b around the changing point occurs, surging can be prevented effectively.

When a large impact torque is input such that the torsion angle exceeds the change point, the point at which the torsion angle increases by θ _{b to the} change point at which the second damper springs 36a and 36b start to be compressed, that is, the torsion when the angle becomes theta _c, it begins to occur the viscosity torque Tb by the viscous damping ribs 33 and the damping ribs 35, which acts as a resistance to the input torque. Moreover since it increased gradually until the change point that the viscous torque Tb, the spring characteristic is the same as gradually changes from a state of twist angle theta _c is upon the phenomenon. As a result, in the torque converter 21, a sudden change in the spring characteristic is substantially prevented, and a sudden change in the output shaft torque and a shock associated therewith do not occur, so that the riding comfort and stability of the vehicle are improved.

Incidentally, the twist angle theta caused by the average maximum torque of the engine, it is preferably configured to be smaller than the initial opening angle theta _c between the attenuation rib 35 and the viscous damping ribs 33.
That is, the viscous damping effect is generated by absorbing the kinetic energy as heat energy due to the shearing of the high-viscosity oil. Therefore, if the angle relationship is configured to satisfy θ <θ _c , the output of the engine is reduced. Part of it is hardly absorbed by the damping action of the viscous damping rib 33 and the damping rib 35, so that deterioration of fuel efficiency can be prevented.

Next, another embodiment of the present invention will be described. FIGS. 7 to 10 show a second embodiment of the present invention. In the first embodiment, both the driven member and the driving member are used. The second damper spring provided in this embodiment is provided only on the drive side member in this embodiment.

7 to 9 show the driven side member 58 and the driving side member 59 of the damper mechanism of this embodiment.
The annular driving side member 59 having a disc-shaped portion and a cylindrical portion on the outer periphery thereof has six concentric annular ribs 59a, 59b,..., 59f on a surface facing the driven side member 58. These annular ribs 59 are formed so as to protrude at a predetermined interval.
a, 59b, ... 59f, that is, among the five valleys,
In the remaining three valleys except between the annular ribs 59b and 59c and between the annular ribs 59d and 59e, an arc-shaped stopper rib 60 is provided.
First damper springs 61a, 61b, 61c having a relatively small spring constant are formed in pairs at the equally dividing positions, and a spacer block 62 is provided between the stopper ribs 60. It is fitted in a sandwiched state. Therefore, the first damper springs 61a, 61c
Are used for each of the three valleys, for a total of 24 valleys.

As shown in FIG. 7, six pairs of viscous damping ribs 63 are formed at equal intervals in a valley between the annular ribs 59b and 59c of the driving side member 59. These viscous damping ribs 63 are 2
One set of strips and one set of two sets, and a second damper spring 66a is fitted between each pair of viscous damping ribs 63.

On the other hand, FIG. 8 is a front view of the driven side member 58, and the surface of the driven side member 58 facing the driving side member 59 has a pushing rib having substantially the same length as the stopper rib 60. 64 are formed. This sandwiches the first damper springs 61a to 61c together with the stopper rib 60, and is provided at a position where the first damper springs 61a to 61c are fitted into the stopper rib 60. Further, at a radial position corresponding to the viscous damping rib 63 on the drive side member 59 side, a set of three damping ribs 65 protrudingly formed, and this damping rib 65 is substantially the same as the viscous damping rib 63. It is arranged so that it is located at the middle part of the viscous damping rib 63 in a state where the torsion angle between the driven side member 58 and the driving side member 59 is “0 °”.

The mutual positions of these ribs in the initial state are as shown in FIG.

When the driven side member 58 and the driving side member 59 are assembled to face each other, a hollow portion between them is held in an airtight state by an appropriate sealing material, and a high level of silicon oil or the like is contained therein. By filling the viscous oil with an appropriate amount of air, a variable displacement type viscous damping mechanism 67 is formed.

In addition, these driven side member 58 and driving side member 59 are
As in the case of the first embodiment, it is accommodated in the housing of the torque converter and assembled in the same manner as shown in FIG.

Accordingly, in a torque converter with a lock-up clutch using the driving side member 59 and the driven side member 58 having the configuration shown in FIGS. 7 and 8, each damper spring and rib act as described below to generate vibration. Reduce and prevent shaking.

That is, FIGS. 10 (A) to 10 (D) are schematic diagrams similar to FIGS. 5 (A) to 5 (D) described above.
In the state of the torsion angle “0 °” shown in FIG. 7, the stopper rib 60 and the pushing rib 64 overlap in the radial direction over the entire length thereof, and the damping rib 65 is
Are located in the middle of and are far apart. Each of the damper springs 61a, 61c, 66a is not compressed beyond the assembled state.

FIG. 10 (B) shows a state in which the torsion angle is increased until just before the torque is input and the viscous damping rib 63 and the damping rib 65 start to wrap. In this state, the first damper springs 61a,. 61c is compressed by the stopper rib 60 and the pushing rib 64, and the ribs 60, 64 are pulled out from between each other, so that no viscous torque is generated. On the other hand, the second damper spring 66a
Is not loaded, and the viscous damping rib 63 and the damping rib 65 do not overlap each other, so that no viscous torque is generated here as well.

When the torsion angle further increases, as shown in FIG. 10 (C), the viscous damping rib 63 and the damping rib 65 start to overlap in the radial direction, and a viscous torque is generated according to the wrap length l2.

The twist angle change point, i.e. an initial opening angle theta _c and the ribs of the damping ribs 65 and the viscous damping ribs 63 63,65
Increasing to an angle obtained by adding the center angle theta _b corresponding to the length of these ribs 63 and 65 begins to compress the second damper springs 66a, and the viscosity torque at that time becomes the maximum.
Beyond this change point, as shown in FIG. 10 (D), the wrap length l2 of these ribs 63, 66a becomes shorter, the amount of compression of the second damper spring 66a increases, and the viscous torque gradually increases. descend.

Therefore, in the second embodiment as well, by reducing the spring constant of the first damper springs 61a to 61c, it is possible to effectively prevent the occurrence of booming noise due to the fluctuation of the engine torque. Can be prevented by the viscous damping mechanism 67 due to the reduction of the thickness. Further, the spring characteristic changes in two steps, but when a large impact torque is input, the second damper spring 66a absorbs a part of the torque to prevent overload, and the first damper spring is also used to prevent shaking. It can be prevented in the same way as in the example. In the second embodiment, the second damper spring 66a is assembled only to the driving member 59, so that the assembling workability is improved.

11 to 14 show a third embodiment of the present invention. In the first and second embodiments, the viscous damping ribs and the damping ribs are provided at equal intervals, and the torsion angle is equal to or larger than a predetermined angle. The structure is such that a viscous torque is generated when it becomes
The third embodiment has a structure in which a small viscous torque is constantly generated.

That is, as shown in FIGS. 11 and 12, between the viscous damping ribs 63 adjacent in the circumferential direction, these ribs are provided.
An arcuate intermediate rib 63a having a small thickness is integrally formed so as to connect the 63, and the damping rib 65 formed on the driven side member 58 sandwiches the intermediate rib 63a with a predetermined gap. In this state, it relatively moves in the circumferential direction. Other configurations are the same as the above-described second embodiment.
The same parts or members are denoted by the same reference numerals as in the second embodiment, and description thereof will be omitted.

Therefore, the damping rib 65 relatively moves from the middle position of the viscous damping rib 63 toward one of the viscous damping ribs 63 as the torsion angle increases according to the input torque. This situation is shown in FIGS. 13 (A) to 13 (D), which are schematic views similar to FIGS. 10 (A) to 10 (D) described above, and show the damping ribs.
Since the damping rib 65 and the intermediate rib 63a relatively move in the shearing direction until 65 starts to overlap the viscous damping rib 63 in the radial direction, that is, in the state shown in FIGS. 13 (A) and 13 (B), Generates viscous torque. However, since the intermediate rib 63a is thin, the gap between the ribs 65 and 63a is wide, and as a result, the generated viscous torque is small.

As shown in FIGS. 13 (C) and (D), when the damping rib 65 enters between the viscous damping ribs 63, since the viscous damping rib 63 is thick, the space between the two ribs 65, 63 is reduced. The gap becomes smaller, and a relatively large viscous torque is applied to both ribs 63 and 65.
Occurs until the lap is resolved.

The functions of the first damper springs 61a to 61c and the second damper spring 66a and the functions of the stopper rib 60 and the pushing rib 64 are the same as those in the second embodiment.

Therefore, in the third embodiment, as shown in the characteristic diagram of FIG.
Also in the initial opening angle theta _c the range of a central angle theta _a higher and a viscous damping ribs 63 and the damping rib 65, resulting viscous torque due be provided intermediate ribs 63a, as a result, at the rated output of the engine Since the viscous damping action is always performed during the running, the effect of preventing the shearing due to the torque fluctuation of the engine is excellent. Of course, the same effects as those obtained in the second embodiment can be obtained.

In each of the above embodiments, the viscous damping ribs 33, 35, 6
3, 65 are arranged at equal intervals in the circumferential direction so that viscous torque is simultaneously generated at a plurality of locations. Can be multi-stage. Further, in this case, if a viscous damping mechanism that acts near each spring characteristic change point is provided, it is possible to reduce a shock caused by a change in the spring characteristic.

Furthermore, in each of the above embodiments, the viscous damping action is generated before and after the torsion angle at which the spring characteristic changes.
The present invention is not limited to the above embodiments,
The angle range in which the viscous damping effect occurs may be one of a predetermined angle range on the small angle side from the change point or a predetermined angle range on the large angle side from the change point, in which case, A change point may or may not be included.

Effect of the Invention As described above, according to the present invention, as described above, a damper mechanism whose spring characteristics change with an increase in torsion angle,
In a predetermined angle range near the torsion angle at which the spring characteristic changes, the resistance to the torsional action of compressing the damper spring is less than the predetermined angle, and the predetermined angle is smaller than the predetermined angle. Since a viscous damping mechanism that generates a viscous damping force that is larger than the resistance force in the angle range of an angle larger than the range is configured, an impact torque is input such that the torsion angle is equal to or greater than the angle at which the spring characteristic changes. Even in such a case, it is possible to effectively prevent the shearing in the vicinity where the spring characteristic changes, thereby improving the riding comfort and the stability of the vehicle.

[Brief description of the drawings]

1 to 6 show a first embodiment of the present invention. FIG. 1 is a sectional side view showing a torque converter, and FIG. 2 is a front view of a driving side member with a damper spring mounted. FIG. 3 is a front view of the driven member, and FIG.
FIGS. 5 (A) to 5 (D) are cross-sectional views taken along line IV-IV of the figure, and FIGS. 5 (A) to 5 (D) are schematic views showing the relationship between the damper spring and the viscous damping rib in a linearly developed manner, FIGS. 7 is a diagram showing the relationship between the torsional characteristic and the generated viscous torque, respectively, FIGS. 7 to 10 show the second embodiment, FIG. 7 is a front view of a driving side member with a damper spring mounted, 8 is a front view of the driven side member, FIG. 9 is a sectional view of a state where the driven side member and the driven side member are abutted, and FIGS. 10 (A) to 10 (D) show a damper spring and viscous damping. FIGS. 11 to 14 show a third embodiment of the present invention. FIG. 11 is a front view of a driving side member with a damper spring mounted, and FIGS. FIG. 13 is a cross-sectional view showing a state where the driving-side member and the driven-side member are in contact with each other. FIGS. FIG. 14 is a schematic diagram showing a relationship between the torsion characteristic and the viscous torque to be generated, FIG. 15 and FIG. 16 show a conventional example, and FIG. Is a longitudinal sectional side view showing a conventional torque converter with a lock-up clutch, and FIG. 16 is a partial sectional front view showing a damper mechanism provided therein. 21 …… Torque converter, 23 …… Housing, 23a ……
Front cover, 24 Pump impeller, 25 Turbine runner, 26 Stator, 27 Output shaft, 28 Driven member, 29 Drive member, 29a, 29b to 29f, 59a, 59b ~
59f: annular rib, 30, 60: stopper rib, 31a, 31b, 31
c, 61a, 61b, 61c: first damper spring, 33, 63: viscous damping rib, 63a: intermediate rib, 34, 64 ... pushing rib, 3
5,65… damping rib, 36,66… second damper spring, 3
9 ... lock-up clutch, 40 ... friction material.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-4629 (JP, A) JP-A-60-192126 (JP, A) Fully open 1986-157746 (JP, U) Really open 1986 182440 (JP, U) Japanese Utility Model Showa 62-4629 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 45/02 F16F 15/12, 15/16

Claims (1)

(57) [Claims] An input element integrally connected to a pump impeller, an output element integrally connected to a turbine runner, and a lock for transmitting power from the input element to the output element by selectively engaging the input element. Fluid transmission with a lock-up clutch having an up-clutch and a damper spring that is compressed in accordance with a torsion torque applied to the lock-up clutch, wherein a spring characteristic changes at a predetermined torsion angle in a direction in which the damper spring is compressed. In the damper mechanism of the device, a resistance force against a torsion action of compressing the damper spring is a resistance in an angle range smaller than the predetermined angle range in a predetermined angle range near the torsion angle at which the spring characteristic changes. Force, and resistance in an angle range greater than the predetermined angle range. A damper mechanism for a hydraulic power transmission with a lock-up clutch, characterized by comprising a viscous damping mechanism that also increases the size.