JPH0320119A - Release bearing driving mechanism of clutch - Google Patents

Abstract

PURPOSE:To provide precise control of a release bearing by rotating a rotating member directly through a motor and changing its rotation into an axial movement to move a release bearing, and employing an ultrasonic motor as this motor. CONSTITUTION:When a motor 14 is operated, a.c. voltage is applied between a point E between two electrodes 17 and a point A apart from it by 90 deg., and between the point A and a point B on its opposite side, so that a surface wave occurs in an elastic ring 17a, and a rotor 18, accordingly a thrust roller 10 rotate around an input shaft 2. A movement transmission mechanism 20 is provided with balls 22, approximately half of which are stored in a ball holding hole 25 provided in the inner surface of the thrust roller 10, and the other half of which are fitted into a cam groove 26 provided in a slave piston 8. In a rotation preventing mechanism 21, the slave piston 8 is jointed to a fixed sleeve 5 so that it may move freely in an axial direction. The rotation of the thrust roller 10 in converted into the axial movement of the slave piston 8 through the above mechanism, so that a release bearing 35 can move in the axial direction with correct action.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a release bearing displacement mechanism used in friction clutches of vehicles such as automobiles, and in particular improves the structure for driving the release bearing. be.

[Prior Art] Generally, in an automobile *m clutch, a release bearing for controlling the connection/disconnection of the clutch/y clutch is connected to the clutch pedal via a mechanical coupling mechanism such as a link mechanism or a lever mechanism. has been done.

Further, in some clutches, a hydraulic cylinder whose operating state can be controlled by a clutch pedal is provided outside the clutch housing, and the cylinder is mechanically connected to the release bearing via a connecting mechanism.

Historically, JP-A-61-180028 describes a structure in which a hydraulic cylinder is provided in the western part of the clutch housing and the hydraulic cylinder is directly connected to a release bearing.

[Problems to be Solved by the Invention] However, in a structure using a mechanical coupling mechanism such as a link as described above, the release bearing may not be accurately controlled due to friction and deformation of various parts. Further, the friction and deformation described above also cause a loss of force transmitted to the release bearing, which causes a problem of reduced clutch operation efficiency, especially in a structure that combines a hydraulic cylinder and a mechanical coupling mechanism.

On the other hand, with a structure in which the hydraulic cylinder is attached directly to the release bearing, as in the above-mentioned Japanese Patent Application Laid-Open No. 61-180028, the above-mentioned problems regarding the coupling mechanism can be solved, but the hydraulic cylinder can generate a large force that can directly drive the release bearing. This requires the extraction cylinder to be large in size, and it is necessary to arrange such a cylinder in the axial direction of the clutch. As a result, the clutch becomes large in size, particularly in its axial dimension. Furthermore, it is necessary to extend the extraction line for the hydraulic cylinder to the inside of the clutch housing, and the structure becomes complicated due to measures such as hydraulic seals on sliding parts.

As a structure for solving the above problem, the applicant of the present invention has proposed a structure using a direct drive type non-commutator motor in Japanese Patent Application No. 1-40664. The present invention further improves such a structure and is disclosed in the above-mentioned patent application No. 1j-1-40664.
The purpose of this paper is to provide a structure that uses an ultrasonic motor in place of the direct drive type non-commutator motor described in the above publication.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a rotating member connected to a motor, and an axially movable member supported by a stationary member so as to be movable only in the axial direction. , comprising a motion conversion mechanism that transmits the quadrupling motion of the rotary member to the axial motion member as the axial motion, and a release bearing coupled to the axial motion member, the motor being an ultrasonic motor, It is characterized by comprising an elastic body and an electrostrictive body fixed to a stationary member, a rotor case directly connected to the rotating member, and a rotating body fixed to the rotor case.

[Operation] According to the above structure, the motor directly drives the quadrilateral member, and more specifically, the rotating member rotates integrally with the rotating body, and the rotational movement is converted in the axial direction by the motion conversion mechanism. The motion is transmitted to the axially moving member, which causes the release bearing to move linearly.

In the above operation, since a motion conversion mechanism is interposed in the power transmission path from the motor to the release bearing, the driving torque required of the motor is small.

In addition, in the above operation, the motor directly drives the rotating member, and specifically, the movement of the rotating body is directly transmitted to the rotating member, so the rotating member operates accurately and reliably in response to the operation of the motor. I am made to do so.

As is well known in history, an ultrasonic motor basically uses an electrostrictive body (ultrasonic excitation part) to vibrate an elastic body, and the vibration (
It has a structure in which the rotating body is rotated by elastic deformation.
High torque is increased by 1 IJ. In addition, in an ultrasonic motor, against the reaction force in the counter-rotation direction applied to the rotating body from the rotating member side,
A large frictional force can be generated between the rotating body and the elastic body, and therefore, in the clutch disengaged state, a braking force (a force in the direction of preventing the rotating body from reversing) due to the frictional force can be generated. This reduces the amount of power required for the motor.

['. Embodiment A] In FIG. 1, the manpower side end portion of the transmission's manpower shaft 2 (only the center line is shown) protrudes to the left in FIG. 1 from the clutch housing 1. A housing sleeve 3 is arranged around the protruding end of the human power shaft 2 at centers II'IJ. The housing sleeve 3 is provided on the inner periphery of the housing 1, and the fixed sleeve 5 is fixedly fitted on the outer periphery of the housing sleeve 3. A cylindrical slave piston 8 is fitted to the outer periphery of the fixed sleeve 5 as described below, and a cylindrical thrust roller 10 is fitted to the outer periphery of the slave piston 8 as will be described later.

There are two or three phases on the radially outer side of the thrust roller 10.
A phase ultrasonic motor 14 is arranged.

Generally, as ultrasonic motors, vibrating piece type ultrasonic motors and surface wave type ultrasonic motors are known, and the illustrated structure employs the latter. Motor 14 directly drives thrust roller 10. That is, the thrust roller 10
is configured to function as an output shaft of the motor 14, and specifically configured as follows. Motor 1
The annular motor case 16 of No. 4 has a dovetail portion fixed to the west peripheral portion of the clutch housing 1 with a plurality of bolts. A ball bearing 12 is disposed between a radially intermediate portion of the motor case 16 and an end portion of the thrust roller 10. An electrostrictive body 17 is attached to the surface of the motor case 16 on the thrust roller 10 side on the radially outer side of the ball bearing 12.

An elastic ring 17a is arranged on the opposite side of the electrostrictive body 17 from the motor case 16. A rotating body 18 is in relatively rotatable contact with the surface of the elastic ring 17a opposite to the electrostrictive body 17 via a slider 17b. The surface of the rotating body 18 opposite to the slider 17b is fixed to the rotor case 19.

One rotor case has a cylindrical outer periphery extending to near the outer periphery of the motor case 16, and a dust cover 51 made of a soft rubber film is attached to the outer periphery of both rotor cases.

Although not shown, a control path is provided on the outside of the housing 1 and is connected to a clutch pedal.

The control circuit is electrically connected to the electrostrictive body 17, and controls the operating state of the electrostrictive body 17 as described below.

When operating the motor 14, the following excitation current is supplied to the electrostrictive body 17 from the control circuit. Figure 2 (
In FIG. 1 (schematic view of arrow 1), two arc-shaped electrostrictive bodies 17 are used, and the electrostrictive body 17 is arranged in an annular shape as a whole. In FIGS. 2 and 3 (drive circuit diagrams in the case of two phases), a point E between both electrostrictive bodies 17 and a point 9 from there
An AC voltage of voltage amplitude VO and angular frequency ω (-2πf) is applied between point A of one electrostrictive body 17 separated by an angular interval of 0 degrees, and between the point E and point A of 90 degrees from there. 90 degrees (π/2) between point B of the other electrostrictive body 17 separated by an angular interval
An alternating current voltage with a phase of is applied.

In this way, the electrostrictive body 17 generates a surface wave in the elastic ring 17a, and the surface wave causes the slider 17b (
contact portion) is moved in the circumferential direction, and the slider 17b
Rotational force is generated in the rotating body 18 due to solid friction and viscous friction between the rotating body 18 and the rotating body 18 .

A rotor case 19 to which the rotating body 18 is fixed has an inner circumference fixed to the outer circumference of the thrust roller 10 by welding or the like. Therefore, when the motor 14 is operated to rotate one rotor case together with the rotor case 18, the thrust roller 10 rotates together with the rotor case.

When the motor 14 is operated as described above, the thrust roller 10 rotates around the human-powered shaft 2. In order to transmit the rotational motion to the slave piston 8 as an axial motion parallel to the input shaft 2, the slave piston 8 is rotated. A ball cam mechanism 20 (motion Buddha mechanism) is located between the thrust roller 10 and the thrust roller 10.
A rotation prevention mechanism 21 is provided between the slave piston 8 and the fixed sleeve 5.

The ball cam machine WI20 includes three or more balls 22 (only one ball is shown) arranged at intervals in the circumferential direction of the slave piston 8. Each ball 22 is partially housed in a hemispherical ball holding hole 25 provided on the inner circumferential surface of the thrust roller 10 in a state where it can rotate freely in all directions. is partially engaged.

Figure 4 is a developed view of the outer peripheral surface of the slave piston, and as is clear from Figure 4, the cam? g26 is slave piston 8
It is formed in a spiral shape on the outer circumferential surface of the release bearing mechanism, and its inclination direction and inclination angle are appropriately set according to the desired operating characteristics of the release bearing mechanism.

As shown in Figure 1, slave piston 8 and thrust roller 1
An annular retainer 24 is disposed between the balls 22, and the plurality of balls 22 are held by the retainer 24 to maintain a constant relative positional relationship.

The rotation prevention mechanism 21 includes a plurality of rollers 28 (only one is shown) arranged at intervals in the circumferential direction of the fixed sleeve 5. Each roller 28 includes two short shafts extending in the radial direction of the fixed sleeve 5 and an outer race 31 that fits around the shaft 29 via a plurality of small diameter rollers 30. The shaft 29 projects further inward in the radial direction than the roller 30 and the outer race 31, and its projecting portion fits into the hole of the fixing sleeve 5 and is fixed. The outer race 31 fits into a groove 32 provided on the inner peripheral surface of the slave piston 8. The groove 32 extends in the axial direction of the slave piston 8.

The anti-rotation device W121 connects the slave piston 8 to the fixed sleeve 5 so as to be movable only in the axial direction. Therefore,
When the thrust roller 10 is rotated by the motor 14, the slave piston 8 is moved in the axial direction by the action of the ball cam mechanism 20.

A release bearing 35 is connected to the slave piston 8. The release bearing 35 is connected to the western circumference of a diaphragm spring of a clutch (not shown). When the release bearing 35 moves in the same direction due to the axial movement of the slave piston 8, the diaphragm spring is deformed and the connection/disconnection operation of the clutch is controlled, as in a general clutch. In a pull type clutch, the clutch is disengaged by pulling the inner periphery of the diaphragm spring toward the housing 1 side by the release bearing 35, but if the structure shown in the figure is adopted for such a clutch, the cam full 26 is set in the opposite direction.

The release bearing 35 is located on the opposite side of the housing 1 with the slave piston 8 interposed therebetween, and includes an outer race 36, a ball 37, and an inner race 38. The slave piston 8 is integrally provided with an outward flange 40 at the end adjacent to the outer race 36, and the end surface of the outer race 36 contacts the end of the flange 40 so as to be slidable in the radial direction.

A cylindrical bearing force bar 41 is provided around the outer race 36. Both ends of the cover 41 are bent inward in the radial direction, and one of the bent ends engages with the flange 40 from the side opposite to the outer race 36. The other bent end of the cover 41 faces the other end surface of the outer race 36, and a self-aligning spring 42 is interposed between the two in a compressed state in the axial direction. The action of the cover 41 and the spring 42 connects the outer race 36 to the slave piston 8 in the axial direction. In addition, if the release bearing 35 and the slave piston 8 are assembled in a relatively eccentric state, if the release bearing 35 rotates with the diaphragm spring during operation, the outer race 36
automatically slides in the radial direction with respect to the slave piston 8, and immediately assumes a concentric positional relationship with the slave piston 8.

The inner lace 38 is the outer lace 36 and the cover 41
It protrudes to the side opposite to the housing 1, and its protruding end is connected to the diaphragm spring.

[Effects of the Invention] As explained above, according to the present invention, the rotational force of the motor 14 disposed near the release bearing 35 is converted into axial motion by the ball cam machine $g20 and transmitted to the release bearing 35. . Therefore, unlike the conventional structure, where a mechanical coupling mechanism consisting of a lever mechanism or link mechanism is placed between the driving force source and the release bearing, this mechanism uses a hole and is not directly driven by an annular balanced force. Therefore, loss or deviation of operating force due to wear or deformation can be prevented, and the operation of the release bearing 35 can be accurately controlled.

Further, according to the present invention, since the motor 14 is an ultrasonic motor, its characteristics (low rotational speed and large torque) are fully exploited, and the response speed necessary for controlling the connection/disconnection operation of the clutch is reduced.

Furthermore, in the ultrasonic motor, friction torque is generated on the surface of the slider 17b, and this torque can be used as a braking force to prevent the motor 14 from reversing in the clutch disengaged state. Another advantage is that the required power is relatively low.

Furthermore, by using an electric motor as the driving force source for the release bearing as shown in the figure, there is no need to extend the hydraulic line to the inside of the clutch housing, so the structure can be simplified and there is no fear of oil leakage.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the length embodiment of the present invention, and Fig. 2 is a - - of Fig. 1.
(2) A schematic cross-sectional view, FIG. 3 is a motor drive circuit diagram, and FIG. 4 is a developed view of the outer circumferential surface of the scraped piston provided with cam grooves. 1...Clutch housing, 5...Fixing sleeve,
8...Slave piston, 10...Thrust roller, 14...Motor, 16...Motor case, 17...
... Electrostrictive body, 17a... Elastic ring, 18... Rotating body, 19... Lower case, 20... Ball cam mechanism, 35... Release bearing

Claims (1)

[Claims] 1. A rotating member connected to a motor, an axially movable member supported by a stationary member so as to be movable only in the axial direction, and the rotational movement of the rotating member as the axial movement. a motion converting mechanism for transmitting data to the axially moving member; and a release bearing coupled to the axially moving member, the motor being an ultrasonic motor, an elastic body and an electrostrictive body fixed to the stationary member; A clutch release bearing drive mechanism comprising a rotor case directly connected to a rotating member and a rotating body fixed to the rotor case. 2. The clutch release bearing drive mechanism according to claim 1, wherein a dust cover made of a soft rubber film for dustproofing is attached to the outer periphery of both the rotor case and the motor case which is the stationary member. 3. The clutch release bearing drive mechanism according to claim 1, wherein the motor is a two-phase or three-phase ultrasonic motor.