JP2004068878A - Clutch device - Google Patents

Abstract

An object of the present invention is to provide a clutch device that operates without relying on hydraulic pressure and can save energy.
A power supply to an input disk is performed by an electric motor of an actuator, so that friction plates can be engaged without using a hydraulic pressure source. Although power is supplied from the worm shaft 3 to the input disk 17 by engagement with the teeth 17a, transmission of power from the input disk 17 to the worm shaft 3 is prevented, so that the friction plates 23, 24 are engaged. While the power is maintained, the power supply to the electric motor 2 can be interrupted, and energy can be saved.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a clutch device capable of selectively transmitting / disconnecting power, and more particularly to a clutch device having a built-in actuator for saving power.
[0002]
[Prior art]
Taking the field of automobiles as an example, in recent years, labor savings have been made to reduce the burden on the driver.For example, to reduce the burden on shifts, automatic transmissions equipped with fluid couplings and the like have been developed. There is a fact that more vehicles are installed.
[0003]
Japanese Patent Application Laid-Open No. 10-30650 discloses an automatic transmission that can transmit power at a desired reduction ratio by performing a combination of a high clutch, a low clutch, and engagement and disengagement of a brake device in combination with a multi-plate type. Have been. Here, for example, the engagement of the high clutch is performed by moving the piston in the axial direction against the urging force of the return spring by hydraulic pressure supplied from a hydraulic pump serving as a hydraulic pressure source, thereby engaging the plurality of friction plates with each other. Power is transmitted through the engaged friction plates.
[0004]
[Problems to be solved by the invention]
However, in such an automatic transmission of the prior art, the hydraulic pressure must be continuously supplied during the engagement of the high clutch, and during this time, the hydraulic pump must be maintained in the operating state. May occur, which may adversely affect fuel economy. On the other hand, the return spring is biased in the direction in which the plurality of friction plates are engaged with each other, and only when the high clutch is disengaged, hydraulic pressure is applied to the piston against the biasing force of the return spring. Is also conceivable. However, in such a configuration, the urging force of the return spring needs to be large enough to prevent the friction plate from slipping. If the piston pressing force is increased so as to be able to withstand this, the size and weight of the device will increase. There is a risk of inviting. If the time for engaging and disengaging the high clutch is shorter than the time for engagement, the hydraulic pressure must be continuously supplied for a long time, and energy saving cannot be achieved.
[0005]
The present invention has been made in view of the problems of the related art, and has as its object to provide a clutch device that operates without relying on hydraulic pressure and can save energy.
[0006]
[Means for Solving the Problems]
The clutch device of the present invention
An input shaft,
An output shaft,
An input-side friction plate that rotates integrally with the input shaft,
An output-side friction plate that rotates integrally with the output shaft,
A pressing device that presses the input-side friction plate and the output-side friction plate against each other,
A clutch device having an actuator for driving the pressing device,
The actuator has an electric motor, a worm connected to the electric motor so that power can be transmitted, and a worm wheel meshing with the worm,
The pressing device presses one of the input-side friction plate and the output-side friction plate toward the other according to the rotational displacement of the worm wheel.
[0007]
[Action]
The clutch device of the present invention includes an input shaft, an output shaft, an input-side friction plate that rotates integrally with the input shaft, an output-side friction plate that rotates integrally with the output shaft, and the input-side friction plate. And a pressing device that presses the output side friction plate with each other, and an actuator that drives the pressing device, wherein the actuator is connected to the electric motor and the electric motor so as to transmit power. A worm and a worm wheel meshing with the worm, wherein the pressing device moves one of the input-side friction plate and the output-side friction plate toward the other in accordance with a rotational displacement of the worm wheel. Since the pressing is performed, power is supplied to the pressing device by the electric motor of the actuator, so that the friction plate can be engaged without using a hydraulic pressure source. In addition, since the actuator transmits power using the worm and the worm wheel, power is transmitted to the pressing device by appropriately designing a lead angle of the worm and the like. The transmission of power from the pressing device can be prevented, so that the power supply to the electric motor can be interrupted while the friction plate is kept engaged, thereby saving energy.
[0008]
Further, the pressing device has a plurality of ramps whose width in the axial direction changes in the circumferential direction, a rolling element that is arranged to be rollable along the ramps, and that is arranged for each of the ramps. It is preferable to have a retainer for holding the rolling element.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a clutch device according to the present embodiment applied to an automatic transmission. FIG. 2 is a view in which the configuration of FIG.
[0010]
In FIG. 1, an electric motor 2 is attached to a housing 1. A female spline 2b is formed on the inner peripheral surface of the end of the rotating shaft 2a where the end of the electric motor 2 is hollow. On the other hand, the worm shaft 3 arranged coaxially with the rotation shaft 2a in the housing 1 has a male spline 3a formed on the outer peripheral surface at the left end of FIG. By doing so, the rotating shaft 2a and the worm shaft 3 can rotate integrally while allowing relative displacement in the axial direction. The connection between the rotating shaft 2a and the worm shaft 3 may be performed by using a key.
[0011]
Both ends of the enlarged diameter portion of the worm shaft 3 are rotatably supported on the housing 1 by bearings 4 and 5, and a worm 3b is formed at the center of the worm shaft 3. The worm 3b meshes with the outer peripheral teeth 17a of the input disk 17, which is a worm wheel. The outer ring of the bearing 4 is urged rightward in FIG. 1 by a pair of disc springs 7 with respect to the sleeve 6 interposed between the motor 2 and the outer ring of the bearing 5. The pair of disc springs 8 urge the bottom of the blind hole 1a to the left in FIG. Further, by changing the length of the sleeve 6 in the axial direction (selection of parts, etc.), the preload of the disc springs 7, 8 can be adjusted. An actuator is constituted by the electric motor 2, the worm shaft 3, and the input disk 17.
[0012]
In FIG. 2, an input disk 17 and an output disk 18 adjacent thereto with a roller 19 (FIG. 3) interposed therebetween are supported on the outer peripheral surface of a cylindrical guide portion 1d formed at the left end of the housing 1. . A male spline 18 a is formed on the outer periphery of the output disk 18 and meshes with a female spline 1 f formed on the inner peripheral surface of the housing 1. That is, the input disk 17 is rotatable with respect to the guide portion 1d via the slide bearing 17s, but the output disk 18 is not rotatable with respect to the guide portion 1d, and the axis is rotated via the slide bearing 18s. It can be displaced only in the direction.
[0013]
FIG. 3 is an expanded view of the boundary between the outer peripheral surface of the input disk 17 and the outer peripheral surface of the output disk 18 in FIG. 2, but the outer peripheral teeth and splines are omitted for easy understanding. FIG. 4 is a perspective view showing an assembly of the retainer 20 and the roller 19 held between the input shaft 17 and the output shaft 18. In FIG. 3, the input disk 17 has four ramp portions 17b that are smoothly inclined so that the axial width increases in one rotation direction, and the output disk 18 also has a correspondingly four ramp portion 17b. It has two ramp portions 18b.
[0014]
Rollers 19 are arranged between the ramp portions 17b and 18b so as to be able to roll freely.
As shown in FIGS. 3 and 4, the rollers 19 are held at equal intervals in a circumferential direction by a retainer 20. The pressing device is constituted by the ramp portions 17b and 18b, the rollers 19 serving as rolling elements, and the retainer 20.
[0015]
2, in the housing 1, an input shaft 21 and an output shaft 22 that includes the input shaft 21 are rotatably supported by bearings (not shown). A male spline 21 a is formed on the outer peripheral surface of the input shaft 21, and five friction plates (input-side friction plates) 23 are formed in the axial direction of the input shaft 21 so that the female splines 23 a are respectively engaged with the male splines 21 a. It is arranged to be displaceable. Similarly, a female spline 22a is formed on the inner peripheral surface of the output shaft 22 whose end is enlarged in diameter, and the male spline 24a is engaged with each of the female splines 22a so that five friction plates (output-side friction plates) are formed. 24 is disposed so as to be displaceable in the axial direction of the output shaft 22 so as to be alternate with the friction plate 23. In FIG. 2, the rightmost friction plate 24 can be brought into surface contact with a receiving plate 25 fixed to the output shaft 22, and the leftmost friction plate 23 is a female spline 22 a of the output shaft 22. Can be brought into surface contact with the push plate 26 with which the male spline 26a is engaged. Thrust roller bearings 27 and 28 are arranged between the housing 1 and the input disk 17 and between the output disk 18 and the push plate 26, respectively.
[0016]
The operation of the present embodiment will be described with reference to the drawings. When a shift is requested by a control device (not shown), power is supplied from a power source (not shown) to the electric motor 2 in FIG. 1, and when the rotating shaft 2a rotates, the worm shaft 3 connected thereto also rotates, and The rotational force is transmitted to the input disk 17 via the worm 3b and the outer peripheral teeth 17a, whereby the input disk 17 rotates counterclockwise in FIG.
[0017]
When the input disk 17 rotates counterclockwise, in the developed view of FIG. 3, the ramp 17b is displaced in the direction of the arrow X, so that the roller 19 is moved toward the side where the axial width of the ramp 17b is large. It rolls, thereby pushing the ramp 18b of the output disk 18. That is, the rotational displacement of the input disk 17 is converted into the axial displacement of the output disk 18, and the displaced output disk 18 presses the push plate 26 in the axial direction, so that the five friction plates 23 and 24 abut, respectively. However, power can be transmitted from the input shaft 21 to the output shaft 22 using the frictional force generated at that time. In particular, since the reduction ratio between the worm 3b and the outer peripheral teeth 17a is large, even if the output of the electric motor 2 is small, a large pressing force can be obtained, which contributes to a compact and low-cost configuration.
[0018]
On the other hand, since the lead angle of the worm 3b is appropriately set, the power supply is stopped after the shift is completed, and in a state where the electric motor 2 is stationary, the frictional force generated between the engaged worm 3b and the outer peripheral teeth 17a causes Even when the reaction force of the pressed friction plates 23 and 24 is applied from the output disk 18 side, the input disk 17 is rotationally locked with respect to the worm shaft 3 (the state where power transmission is blocked). It becomes. At this time, since the disc springs 7 and 8 exert the urging force, the worm shaft 3 is also prevented from moving in the thrust direction (rattle), and the slight rotation of the input disk 17 due to the rattle is also prevented. Therefore, the contact between the five friction plates 23 and 24 is ensured, whereby the power transmission from the input shaft 21 to the output shaft 22 is maintained. That is, there is no need to supply electric power to the electric motor 2 for maintaining the contact between the friction plates 23 and 24, and energy saving can be achieved.
[0019]
Further, when a shift is requested by a control device (not shown), electric power of an opposite phase is supplied to the electric motor 2 from a power source (not shown), and if the rotation shaft 2a rotates in the opposite direction, the input disk 17 is also inverted. 1 (clockwise in FIG. 1), and the rollers 19 roll toward the side where the axial width of the ramp 17b is thin, so that the output disk 18 is not pressed. Is released, and the power transmission from the input shaft 21 to the output shaft 22 is interrupted.
[0020]
As described above, the present invention has been described with reference to the embodiments. However, the present invention should not be construed as being limited to the above embodiments, and it is needless to say that modifications and improvements can be made as appropriate. It goes without saying that the present invention can be applied not only to vehicles but also to many devices such as industrial machines.
[0021]
【The invention's effect】
The clutch device of the present invention includes an input shaft, an output shaft, an input-side friction plate that rotates integrally with the input shaft, an output-side friction plate that rotates integrally with the output shaft, and the input-side friction plate. And a pressing device that presses the output side friction plate with each other, and an actuator that drives the pressing device, wherein the actuator is connected to the electric motor and the electric motor so as to transmit power. A worm and a worm wheel meshing with the worm, wherein the pressing device moves one of the input-side friction plate and the output-side friction plate toward the other in accordance with a rotational displacement of the worm wheel. Since the pressing is performed, power is supplied to the pressing device by the electric motor of the actuator, so that the friction plate can be engaged without using a hydraulic pressure source. In addition, since the actuator transmits power using the worm and the worm wheel, power is transmitted to the pressing device by appropriately designing a lead angle of the worm and the like. The transmission of power from the pressing device can be prevented, so that the power supply to the electric motor can be interrupted while the friction plate is kept engaged, thereby saving energy.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a clutch device according to an embodiment applied to an automatic transmission.
FIG. 2 is a view of the configuration of FIG. 1 cut along a line II-II and viewed in a direction of an arrow.
3 is an expanded view showing a boundary between an outer peripheral surface of an input disk 17 and an outer peripheral surface of an output disk 18 in FIG. 2;
4 is a perspective view showing an assembly of a retainer 20 and a roller 19 held between an input shaft 17 and an output shaft 18. FIG.
[Explanation of symbols]
Reference Signs List 1 housing 2 electric motor 3 worm shaft 4, 5 bearing 17 input disk 19 roller 18 output disk 21 input shaft 22 output shaft 23, 24 friction plate

Claims (2)

An input shaft,
An output shaft,
An input-side friction plate that rotates integrally with the input shaft,
An output-side friction plate that rotates integrally with the output shaft,
A pressing device that presses the input-side friction plate and the output-side friction plate against each other,
A clutch device having an actuator for driving the pressing device,
The actuator has an electric motor, a worm connected to the electric motor so that power can be transmitted, and a worm wheel meshing with the worm,
The clutch device, wherein the pressing device presses one of the input-side friction plate and the output-side friction plate toward the other in accordance with a rotational displacement of the worm wheel. The pressing device includes a plurality of ramps whose width in the axial direction changes in the circumferential direction, a rolling element rotatably arranged along the ramp, and the rolling element arranged for each ramp. The clutch device according to claim 1, further comprising a retainer for holding the clutch.

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