JPS59151632A - Power transmission system torsional vibration absorber for vehicle - Google Patents

Abstract

PURPOSE:To make the wearproofness of both cam plates improvable upon making them into a surface contact state, by making up each cam incline of first and second cam plates to be installed in a power transmission route with part of a spiral surface on the rotating axial circumference of each cam. CONSTITUTION:First and second cam plates 161 and 162 to be installed in a power route are formed in an expression alpha<beta made by a first incline (a) of an oblique angle alpha used in time of acceleration and a second incline (b) of another oblique angle beta used in time of deceleration each. Accordingly, with both cam plates parted away, such force that increases the friction force of a friction plate grows large in time of acceleration in the same torque and thereby there is easy to produce a slip so that a good adjustable speed characteristic is securable. Moreover, since each of inlines (a) and (b) is formed by part of a spiral surface S on the central axial circumference of each of these cam plates 161 and 162, at whatever relative rotation position they may be, both inclines (a) and (b) themselves being face-to-face come into a surface contact state. Like this way, cam surface pressure is held down to the minimum and its wearproofness is thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a torsional vibration absorbing device in a power transmission system of a vehicle such as an automobile.

As such a device, the present applicant has developed a device in which a first shaft connected to the driving side and a second shaft connected to the driven side are fitted so as to be relatively rotatable, and these two shafts slip when receiving a transmitted torque of a predetermined value or more. The friction force is connected through a friction transmission device set as follows.
The power path of this friction transmission device is interposed with first and second cam plates that rotate relative to each other when receiving the torque, and the opposing surfaces of these cam plates have a A method has already been proposed in which a cam is formed to separate both cam plates so as to slide on each other to increase the frictional force of the friction transmission device. According to this configuration, torsional vibration caused by torque fluctuations in the power transmission system can be absorbed by the sliding of the friction transmission device and the relative rotation of the first and second cam plates. A large torsional vibration absorber can be obtained.

By the way, the device proposed above has the first
Since the second cam plate adjusts the frictional force of the friction transmission device by causing relative rotation, the slopes of the cams of both cam plates slide against each other while receiving a large thrust load. There is room for improvement in cam durability, personnel, and especially wear resistance.

The present invention has been proposed in view of this problem, and the cams on both cam plates are always in surface contact regardless of the relative rotational position of the cam plates. The object of the present invention is to provide the above-mentioned device which minimizes pressure and improves its wear resistance.The feature is that the slope of the cam is formed by changing the slope of the cam to a part of the helical surface around the axis of rotation of each cam plate. It is located where it was formed by the department.

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
Figure 1 shows the transmission 1 and its surrounding parts of a front-engine, front-wheel-drive vehicle with engine side gear.
(not shown), and its input shaft 2 is connected to the crankshaft 3 of the engine via a starting clutch 4.The transmission 1 has an output shaft parallel to the input shaft 2. 5 is provided, and a final drive gear 6 integrally provided on the output shaft 5 is meshed with a final driven gear 8 of a differential device 7.

The input shaft 2 is integrally provided with low speed 1st and 2nd speed drive gears 9+192 and a reverse drive gear 9R, and is further provided with medium and high speed 3rd to 5th speed drive gears 9g, 94.
-95 are rotatably supported via needle roller bearings 323 and 324325, respectively.

These third to fifth speed drive gears 93. 9= ,9
5 is selectively connected to the input shaft 2 by switching clutches io, io' and driven thereby. The output shaft 5 includes a tubular shaft 11 and a plain bearing 25.
, 25, and this gear 29R is supported via a switching clutch 13.

These 1st and 2nd speed driven gears 121.122 are connected to the 1st and 2nd speed drive gears 91.9□ of the input shaft 2, and the reverse driven gear 1277 is connected to the reverse drive gear 9R via an idle gear (not shown), respectively. engaged, switching clutch 1
3 is selectively connected to the tubular shaft 11 to drive it.

The tubular shaft 11 also has a 3-speed driven gear integrated with it.
A gear 123 is provided, and this gear 123 meshes with the third speed drive gear 93. The output shaft 5 further includes 4th and 5th driven gears 12.96 which mesh with the 4th and 5th speed drive gears 94.96, respectively. s,, 125 are each spline-connected trees.

A cylindrical extension 14 is formed on the tubular shaft 11 and extends in the axial direction adjacent to the third speed driven gear 123 . A spline 15 is formed on the inner surface of the cylindrical extension 14, and a first cam plate 16. be slidably engaged. Further, an inner cylinder 17 is fixed to the outer periphery of the output shaft 5 between the third speed driven gear 123 and the fourth speed driven gear 124, and an outer cylinder 18 surrounding the inner cylinder 17 is connected to the extension part 1.
It is located adjacent to 4. Outer peripheral surface of inner cylinder 17 and outer cylinder 1
Splines 19 and 20 are respectively formed on the inner circumferential surface of 8, and a plurality of driving friction plates 21 and driven friction plates 22, which are alternately superposed, slide on these splines 19 and 20, respectively. This friction plate 21.
22nd group and first cam plate 16. A second cam plate 162 that engages with the spline 20 of the outer cylinder 18 is interposed between the two, and a pressure receiving plate 23 is interposed between the two and the two. And extension part 1
4 and the second cam plate 16□ is a primary spring 24. which always presses the second cam plate 162 toward the pressure receiving plate 23 with a constant elastic force. is compressed, and furthermore, a support plate 17a and a first cam plate 16 provided at the end of the inner cylinder 17 on the third speed driven gear 123 side are provided.
．． Between both cam plates 16. , 16□, which will be described later, is interposed with a secondary spring 24□ that exerts a resilient force. These springs24. ．． 242 is composed of multiple disk springs, but the spring constant of the primary spring 24□ is lower (
, the secondary spring 242 is set higher.

Thus, the inner cylinder 17, the outer cylinder 18, the driving and driven friction plates 21.
22 and the primary and secondary springs 24□ and 24□ constitute a friction transmission device 26 of the present invention, and the tubular shaft 11 and the output shaft 5 are connected via this friction transmission device 26. Therefore, the tubular shaft 11 connected to the engine side, that is, the drive side, corresponds to the first @J of the present invention, and is a wheel, that is, a driven (ill
An output shaft 5 (corresponding to the second shaft of the present invention) is connected to the output shaft 5 (corresponding to the second shaft of the present invention).

First and second cam plates 16. ．． 16□σ On the opposing surface, as shown in FIG.
．． 28 are integrally protruded from each other, and these are interlocked with each other.

From the top of each cam 27,28 each cam plate 16, . 1
It has a first slope a for positive load transmission that descends in opposite directions along the circumferential direction of 6□, and a second slope a for reverse load operation, as shown in Figure 3. As such, the inclination angle α of the first slope α is relatively small, and the inclination angle β of the second slope α is set relatively large.

In addition, each slope α, b is formed by a part of the spiral surface S around the center axis of each cam plate 16°, 162, so that both cam plates 1sl, 16□σ can be rotated at any relative rotational position. , the opposing first slope α.

Surface contact between the surfaces a and the second slopes S and B is maintained.

Inside the output shaft 5, a tubular shaft 11, a driven gear 12, . 1
Is there an oil supply path 30 for lubrication such as 2□?
This refueling guard 30 is further extended, and an extension part 14 and each section 1
Oil is also supplied to the inside of 8.

Next, to explain the operation of this embodiment, normally the primary spring 24. The elastic force of the second cam plate 162 and the friction plate 21.2
Since the second group is pressed against the pressure receiving plate 23, a predetermined frictional force is applied between the driving and driven friction plates 21 and 22.
On the other hand, the secondary spring 24□ is in the state of being almost inactive.
The cams 27 and 28 of the second cam plates 16□ and 16□ are most deeply engaged with each other as shown in FIG.

Now, by operating the switching clutch 13, the first speed driven gear 12. is connected to the tubular shaft 11, and the rotational torque transmitted from the crankshaft 3 to the input shaft 2 is the rotational torque transmitted from the crankshaft 3 to the input shaft 2.
The cam plate 161, the cams 27° 28, the second cam plate 16□, and the outer cylinder 18 are sequentially rotated and transmitted to the drive friction plate 21. The rotational force of the driving friction plate 21 is applied to the driven friction plate 22 by the frictional force, and is transmitted to the output shaft 5 via the inner cylinder 17 and finally to the differential gear 7 via the drive gear 6. be done.

When the second speed driven gear 12□ or the reverse driven gear 12R is connected to the tubular shaft 11, the torque of the input shaft 2 is transmitted to the output shaft 5 through a similar path. Also, 3rd speed 1st
When the drive gear 93 is connected to the input shaft 2 by the switching clutch 1°, the rotational torque of the input shaft 2 passes through the 3rd speed drive gear 93, the 3rd speed driven gear 123, and the tubular shaft 11.
The signal is transmitted to the extension portion 14, and thereafter is transmitted to the output shaft 5 in the same manner as in the first speed. When the 4th speed drive gear 94 or the 5th speed drive gear 95 is connected to the input shaft 2, the torque of the input shaft 2 is
．． It is directly transmitted to the output shaft 5 through.

When the engine is suddenly accelerated during first to third gear or reverse operation, the rotational speed of the input shaft 2 tends to increase, whereas the output shaft 5 tries to maintain the same speed due to the inertia of the wheels. Therefore, a difference in rotational speed occurs between the tubular shaft 11 and the output shaft 5. As a result, slippage occurs between the driving and driven friction plates 21 and 22, and at the same time,
Relative rotation also occurs between the first and second cam plates 161.16□0, and both cam plates 16. , 16□ are displaced away from each other, and the first cam plate 161 compresses the secondary spring 242 to bring it into operation.

In this way, the fluctuation of the transmitted energy of the input shaft 2 is reduced by the friction plate 2.
1 and 22, and both cam plates 16I.

162, and the rotational speed of the output shaft 50 increases smoothly. And both cam plates 161.16
When the secondary spring 24□ is actuated and its elastic force is increased by the separation action of 2, the frictional force between the friction plates 21 and 22 is also increased, and the torque of the input shaft 2 is reliably transmitted to the output shaft 5. Become so. During this time, the oil in the transmission case is supplied between the friction plates 21 and 22 via the oil supply path 30, so that the frictional heat generated between each friction plate 27 and 22 can be cooled. can.

On the contrary, when a sudden deceleration operation is performed, the input shaft 2 is driven from the output shaft 5, resulting in a reverse load state. A rotational speed difference in the direction occurs. As a result, a slip occurs between the driving friction plate 21 and the driven friction plate 22, and a relative rotation also occurs between the first and second cam plates 160, 16□, but in this case, the relative rotation Since the direction of the cam plate 16. is opposite to that during the acceleration operation, the sliding action of the second slopes of the cams 27 and 28 causes the cam plates 16. ．． A separation force is applied between the driving and driven friction plates 21. ．． 22 is increased. In this way, the reverse load on the output shaft 5 is buffered and transmitted to the input shaft 2.

By the way, in this embodiment, the first
Since the inclination angle β of the second slopes S and b of the second cam plate 161 and 162 is set to be larger than the inclination angle α of the first slopes a and α that operate during acceleration operation, the same torque is applied. Considering the case, the separation force between the two cam plates 161, 16□ caused by the mutual sliding action of the first>pljnt a# a is stronger than the separation force between the two cam plates 161, 16□ caused by the mutual sliding action of the second diagonal @3b, b. The separation force between 168 and 16□ is smaller, and therefore the friction force of the driving and driven friction plates 21 and 22, which is increased by the separation force, becomes smaller during acceleration operation and smaller during deceleration operation. j The tension and the sliding between the driven friction plates 21 and 22 are suppressed to the minimum necessary for absorbing torsional vibrations, and the torque is transmitted quickly;
During deceleration operation, the driving and driven friction plates 21 and 22 are made to slide easily, and torque fluctuations are sufficiently absorbed, resulting in a smooth engine braking effect.

Regardless of whether the operating state is acceleration or deceleration, and regardless of the relative rotation angle of both cam plates 161 and 16 degrees,
As mentioned above, since the first slopes q and a formed by a part of the spiral surface S or the second slopes can always maintain a surface contact state, the surface pressure acting on the contact surfaces can be minimized. can be suppressed to

Torque fluctuations between the input and output shafts 2 and 5 caused by switching of the switching clutches io, io' or 13;
In other words, the shift shock is also absorbed in the same manner as described above, and as described above, according to the present invention, the guide surfaces of the cams of the first and second cam plates are absorbed by a portion of the helical surface around the rotational axis of each cam plate. As a result, the contact state between the cams on both cam plates can always be kept in a surface contact state regardless of the relative rotational position of both cam plates. The wear resistance can be significantly improved.

[Brief explanation of drawings]

Figure a31 shows a torsional vibration absorbing device 1 according to an embodiment of the present invention.
Fig. 2 is an exploded perspective view of the first and second cam plates of the same device, and Fig. 3 is a sectional view showing the meshing state of the chevron cams of both cam plates. . a... First slope, b... Second slope, S... Spiral surface 1... Transmission, 3... Crankshaft, 5... Output shaft as second shaft, 7... ... Differential device, 11 ... Tubular shaft as first shaft, 161.16□ ... First. Second cam plate, 26...Friction transmission device, 2γ, 28...First. Cam patent applicant for the second cam plate Mizuta Giken Kogyo Co., Ltd.

Claims (1)

[Claims] A first shaft connected to the driving side and a second shaft connected to the driven side are fitted so that they can rotate relative to each other, and a friction force is set so that these two shafts slip when receiving a transmitted torque of a predetermined value or more. Connected via a transmission device, and connected to the power path of this friction transmission device,
First and second cam plates are interposed that generate relative rotation when the torque is applied, and the opposing surfaces of these cam plates slide against each other in response to the relative rotation of both cam plates, thereby transmitting the friction. In a vehicle power transmission system torsional vibration absorbing device formed with a cam that separates both cam plates so as to increase the frictional force of the device, the first and second cam plates slide when a positive load is applied. It has a first slope and a second slope that slides when a reverse load is applied,
A torsional vibration absorbing device for a power transmission system of a vehicle, wherein the first and second slopes are formed by a portion of a spiral surface around the rotational axis of each of the cam plates.