JPH0617843A - Friction clutch engaging/disengaging operation control actuator - Google Patents

Abstract

PURPOSE:To obtain a friction clutch engaging/disengaging operation control actuator provided with adjusting mechanism to the wear of a friction member with simple constitution. CONSTITUTION:A friction clutch engaging/disengaging operation control actuator is provided with a rotatory-driving shaft 52, an electric motor for driving the rotatory-driving shaft 52, motion converting mechanism 60 for converting the rotary motion of the rotatory-driving shaft 52 into axial motion, and release forks 7c, 7d for connecting the motion converting mechanism 60 to a friction clutch. The motion converting mechanism 60 is formed of a first slider 62 screwingly fitted onto the rotatory-driving shaft 52, and a second slider 65 screwingly fitted onto the first slider 62; and one ends of the release forks 7c, 7d are connected to the second slider 65 being axially pressed thereto receiving the reaction of a diaphragm spring. The first slider 62 comes in contact with a stopper 67 at the axially moving stroke end so as to be rotated integrally with the rotary shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator used for controlling engagement / disengagement of a friction clutch of a type which is frictionally engaged by receiving a pressing engagement force of a built-in diaphragm spring or the like.

[0002]

2. Description of the Related Art Conventionally, a friction clutch of this type has been arranged between an engine output shaft and an input shaft of a transmission and is used to control engagement / disengagement between the engine and the transmission at the time of shifting. Is used for. Conventionally, engagement / disengagement control of the friction clutch in such a transmission is performed by operating a clutch pedal, and is mainly used in a manual transmission. However, recently, an automatic transmission in which a clutch pedal operation and a speed change lever operation in a manual transmission are automatically performed by using hydraulic pressure and the like are being put into practical use. Therefore, the structure itself of this automatic transmission is the same as that of the conventional manual transmission, and the friction clutch of the above-mentioned type is used, and a mechanism for automatically performing the clutch operation and the speed change operation is added to the structure. Has become.

By the way, in such an automatic transmission, the operation control of the friction clutch is generally performed by using hydraulic pressure, but recently, electric actuators are used instead of hydraulic pressure to utilize electric power. It has also been proposed to perform engagement / disengagement control of the friction clutch. For example, JP-A-63
Japanese Patent Laid-Open No. 203958 discloses an electric actuator that converts a rotational torque of an electric motor into a thrust force by a ball screw mechanism and controls engagement and disengagement of a friction clutch by the thrust force. It should be noted that this friction clutch is provided with a spring that biases it toward the disengagement side, and this friction clutch is normally in the disengaged state. When the rotational torque of the electric motor is converted into a thrust force by the ball screw mechanism and transmitted to the friction clutch, the friction clutch receives the thrust force and is engaged.

However, a friction clutch that has been generally used in the past is configured to be normally engaged by being urged by a built-in diaphragm spring or the like. For this reason, in JP-A-60-256671, in the friction clutch having such a structure, the rotational force of the electric motor is converted into the pressing force of the release bearing of the friction clutch, and the release bearing is pushed to release the friction clutch. Is disclosed. In addition, this actuator has a compensating mechanism using a spring force inside, and the friction clutch can be released by a small rotating force of an electric motor.

[0005]

It is possible to control the engagement and disengagement of the friction clutch by using the actuator as described above. In such engagement and disengagement control, the engagement capacity of the friction clutch with respect to the operation of the actuator can be accurately determined. If it is not understood, it is not possible to perform good engagement / disengagement control. The engagement capacity of the friction clutch can be detected, for example, from the spring pressing force of the diaphragm spring, and this spring force can be detected from the position of the release bearing. Here, since the actuator described above presses the release bearing, it is considered that the engagement capacity of the friction clutch can be detected by detecting the operating position of the actuator.

However, since the friction member of the friction clutch wears depending on use, when the friction member wears, the position of the release bearing changes accordingly. Therefore, there is a problem that the engagement capacity of the friction clutch cannot be accurately detected only by detecting the operating position of the actuator. Further, as the operation stroke of the actuator, it is necessary to secure a stroke amount sufficient for engaging and disengaging the friction clutch even when such friction member wear occurs. For this reason, there is also a problem that the actuator becomes larger by that amount and the space required for the arrangement becomes larger.

In view of such a problem, Japanese Patent Laid-Open No. Sho 60
Japanese Patent No. 241526 discloses an actuator for friction clutch actuation control having a mechanism for automatically adjusting clutch wear using a ratchet. However, this mechanism has a problem that its structure is complicated. Also, if a control system that detects the operating state of the friction clutch relative to the operation of the actuator, performs learning control based on this, and updates each data according to the wear of the friction member, even if wear occurs Accurate engagement control of the friction clutch is possible, and adjustment for wear of the friction member is unnecessary. However, this causes a problem that various detection devices and control devices become complicated, and control becomes complicated and difficult.

The present invention has been made in view of these problems.
It is an object of the present invention to provide an actuator for controlling engagement / disengagement of a friction clutch, which actuator has an adjusting mechanism for abrasion of a friction member and has a simple structure.

[0009]

In order to achieve such an object, in the present invention, a rotary drive shaft rotatably supported by a housing, and drive control means for controlling the rotary drive of the rotary drive shaft, An actuator is composed of a motion converting means for converting the rotary motion of the rotary drive shaft into an axial motion and a connecting means for connecting the motion converting means and the friction clutch, and the motion converting means is provided through the connecting means. The converted axial movement is transmitted to the friction clutch to release the engagement force of the engagement spring. Further, the motion converting means is mounted on the rotary drive shaft by screwing and is moved in the axial direction according to the relative rotation with respect to the rotary drive shaft, and is screwed on the first slider. And a second slider attached to the first slider so as to move relative to the first slider in the axial direction in response to relative rotation with respect to the first slider. It receives a force and is axially pressed against the second slider to be connected to the second slider. When the reaction force of the engaging spring force is received from one end of the connecting means, the rotation drive shaft and the first
With respect to the first frictional resistance torque Tf1 acting on the relative rotation with the slider, the second frictional resistance torque Tf2 acting on the relative rotation with the first slider and the second slider, and the rotation of the second slider. The third frictional resistance torque Tf3 acting by friction with one end of the connecting means is configured to satisfy Tf1 <Tf2 <Tf3, and the first slider is the end of the axial movement stroke accompanying the rotation of the rotary shaft. In the above, it abuts on the stopper and rotates integrally with the rotary shaft.

In this case, the first screw for screwing the first slider on the rotary drive shaft and the screw for the second screw screwing the second slider on the first slider both have flank surfaces. Contacting screws can be used. At this time, it is desirable to set the first flank angle α of the first screw for screwing to be smaller than the second flank angle β of the second screw for screwing.
It is easy to set the relationship of <Tf2. Further, a ball screw is used as a first screw for screwing the first slider on the rotary drive shaft, and a screw whose flank surfaces contact each other as a second screw for screwing the second slider on the first slider. Or you can use
It is easy to set the relationship of Tf1 <Tf2.

On the other hand, at the contact portion between the second slider and the connecting means, the contact angle γ corresponding to the flank angle at this portion is preferably larger than the flank angle β of the second screw for screwing. Then, it is easy to set the relationship of Tf1 <Tf2 <Tf3. Further, at the contact portion between the second slider and the connecting means, one of the second slider and the connecting means may be provided with a friction member having a large friction coefficient. Even in this case, the relationship of Tf1 <Tf2 <Tf3 can be easily set.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In the figure, the arrow U indicates the upper side and the arrow R indicates the right side. A friction clutch engagement / disengagement control actuator according to the present invention is for controlling the operation of a main clutch (a clutch that connects and disconnects an engine output shaft and a transmission input shaft) in an automatic transmission having the same structure as a conventional manual transmission. Used as.

A schematic structure of a power transmission system of the automatic transmission AT is shown in FIG. The automatic transmission AT is a main clutch MC mounted on the flywheel W of the engine E.
The main clutch MC is operated and controlled by the engagement / disengagement control actuator 50 according to the present invention.

The main clutch MC is, as shown in detail in FIG. 1, a cover 1 attached to a flywheel W.
And the friction disk 3 located between the pressure plate 4 and the flywheel W in the cover 1.
And a diaphragm spring 2 supported by the cover 1 and pressing the pressure plate 4 toward the friction disc 3. Normally diaphragm spring 2
The friction disc 3 is sandwiched between the flyhole W and the pressure plate 4 by the pressing force of, and the friction disc 3 is rotated integrally with the output shaft ES of the engine E. The inner diameter hub 3a of the friction disc 3 is spline-coupled to the main shaft 10 of the automatic transmission AT. In this state, the main shaft 10 and the engine output shaft ES are connected via the friction disc 3.

A release bearing 6 can come into contact with the inner peripheral end of the diaphragm spring 2 from the left side, and the release fork 7 is attached to the release bearing 6.
One end 7b of the abuts from the left side. The release fork 7 is swingably supported by the transmission housing 8 at the intermediate portion 7a, and the other end 7c is connected to the motion converting mechanism 60 of the engagement / disengagement control actuator 50 from the left side as shown in the drawing. . The motion conversion mechanism 60 is mounted on a rotary drive shaft 52 that is rotationally driven by an electric motor 51 via a ball screw or the like. Rotary drive shaft 5
Reference numeral 2 is rotatably supported by ball bearings 54a and 54b, and when it is rotationally driven by the electric motor 51, the other end 7c of the release fork 7 is moved to the left and right in the axial direction via the motion converting mechanism 60 by the action of a ball screw or the like. Let

For example, when the motion converting mechanism 60 is moved to the right, the other end 7c of the release fork 7 connected to this is converted.
Is also moved to the right, and the release fork 7 is swung clockwise around the intermediate portion 7a. By this swinging, the release bearing 6 is moved to the left together with the one end 7b, and the diaphragm spring 2 is brought into a substantially free state.
As a result, the spring force of the diaphragm spring 2 acts so as to press the pressure plate 4, the friction disc 3 is sandwiched between the flywheel W, and the main clutch MC is turned on. Note that FIG. 1 shows the state at this time. On the contrary, when the motion converting mechanism 60 is moved to the left, the action opposite to the above is performed and the main clutch MC is turned off (disengaged). An electromagnetic brake 53 is attached to the rotary drive shaft 52, whereby the release fork 7 can be fixedly held at an arbitrary position and the main clutch MC can be held in an arbitrary engaged state.

Further, the motion converting mechanism 60 is provided with a sensor shaft 58 of a stroke sensor 58 via a connecting plate 56.
a is connected, the axial position of the motion conversion mechanism 60,
That is, the engagement state of the main clutch MC can be detected by the stroke sensor 58.
The motion converting mechanism 60 has a function of correcting the wear of the friction disc 3, so that the stroke sensor 58 can accurately detect the engaged state even when the friction disc 3 is worn.

The structure and operation of the motion converting mechanism 60 including this function will be described with reference to FIGS. 3 and 4. The motion converting mechanism 60 includes a first slider 62 mounted on a rotary drive shaft 52 via a first screw 61 for screwing.
And the second screw 63 for screwing on the first slider 62.
And a second slider 65 attached via. Here, the first screw 61 for screwing is a ball screw,
The first frictional resistance torque Tf1 for the rotation is quite small. On the other hand, the second screw for screwing is a conventional screw whose flank surfaces directly contact each other, and the second frictional resistance torque Tf2 against its rotation is larger than that of the ball screw. Therefore, Tf1> Tf2. The second frictional resistance torque Tf2 when receiving the axial thrust force is determined according to the screw flank angle β, and the larger the screw flank angle β, the larger the second frictional resistance torque Tf2.

A conical taper surface 65a is formed on the outer periphery of the second slider 65, and the other end 7c of the release fork 7 has a taper surface 7d that abuts against this taper surface 65a.
Are formed. There is also frictional resistance at the abutting portions of the taper surfaces 65a and 7d, so that when the second slider 65 rotates, the third frictional resistance torque T at this abutting portion.
f3 occurs. The third frictional resistance torque Tf3 is determined according to the contact angle γ of the tapered surfaces 65a and 7d.
Is larger, the third frictional resistance torque Tf3 is also larger. The contact angle γ is the flank angle β of the second screw 63.
It is set to a larger angle.

The first slider 6 is mounted on the rotary drive shaft 52.
A stopper 67 is provided that abuts when 2 moves to the right. Further, the connecting plate 56 is connected to the left end portion of the first slider 62, and the stroke sensor 58 detects the axial movement position of the first slider 62.

In the motion converting mechanism 60 having such a structure, the first to third frictional resistance torques Tf1 to Tf3 are shown in FIG. 7 according to the pressing reaction force F of the diaphragm spring 2 applied via the release fork 7. To change. The first and second frictional resistance torques Tf1 and Tf2 are frictional resistance torques generated in the screw portion, and even if the pressing reaction force F is zero, there are predetermined frictional resistance torques T1 and T2, and the pressing reaction force F increases. The value increases as you do. Here, the first frictional resistance torque Tf1 is a torque generated in the ball screw portion and its resistance is small. Therefore, the relationship is always Tf1 <Tf2.

On the other hand, as for the third frictional resistance torque Tf3, the other end 7c of the release fork 7 receives the pressing reaction force F of the diaphragm spring 2 and the taper surface 65 of the second slider 65.
Since it is generated by being pressed against a, when the pressing reaction force F is zero, the third frictional resistance torque Tf3 also becomes zero,
It increases as the pressing reaction force F increases. Here, since the contact angle γ of the tapered surfaces 65a and 7d is set to be larger than the flank angle β of the second screw 63, the increase rate of the third frictional resistance torque Tf3 with respect to the increase of the pressing reaction force F is increased. Is greater than the rate of increase of the first and second frictional resistance torques Tf1 and Tf2. Therefore, the pressing reaction force F is the predetermined value F
In the area larger than 1, as shown in the figure, Tf1
The relationship <Tf2 <Tf3 is established.

Here, the electric motor 51 drives the rotary drive shaft 52 to move the motion converting mechanism 60 to the state shown in FIG. 1 (that is, the state where the main clutch MC is turned on (connected)).
Consider the case of moving from to the left. Motion conversion mechanism 6
When 0 is moved to the left, the release fork 7 is swung counterclockwise, and the inner peripheral portion of the diaphragm spring 2 is pulled out to the right through the release bearing 6. In response to this, from the other end 7c of the release fork 7 to the second slider 65
The pressing reaction force F applied to is gradually increased. Here, when the pressing reaction force F is larger than the predetermined value F1, the relationship of Tf1 <Tf2 <Tf3 is established as described above. Therefore, when the rotary drive shaft 52 is rotationally driven, the first value is the smallest. Where the frictional resistance torque Tf1 is generated, that is, the first
Only the screw (ball screw) 61 for screwing relatively rotates.

Therefore, the first and second sliders 6 are
The reference numerals 2 and 65 do not rotate in accordance with the rotation of the rotary drive shaft 52, but are moved leftward in the axial direction as they are. As a result, the release fork 7 is swung counterclockwise, the pressing force of the diaphragm spring 2 applied to the pressure plate 4 is released, and the main clutch MC is turned off as shown in FIG.

From this OFF state, this time the rotary drive shaft 52
When it is rotationally driven in the opposite direction, only the first screwing screw 61 having the smallest frictional resistance torque is also relatively rotated at this time, and the first and second sliders 62 and 65 rotate in accordance with the rotation of the rotary drive shaft 52. Without moving, it is moved to the right in the axial direction. As a result, the release fork 7 is swung clockwise, the pressing force of the diaphragm spring 2 applied to the pressure plate 4 is gradually increased, and the main clutch MC is gradually turned on.

When the motion converting means 60 is moved to the right in this way, first, the right end surface of the first slider 62 comes into contact with the stopper 67 as shown in FIG. Even if the rotary drive shaft 52 is further rotated in this state, the first slider 62 cannot move further to the right, so that the friction resistance torque Tf1 of the first screw 61 is infinite. Become. Therefore, the first slider 62 rotates only integrally with the rotary drive shaft 52, does not move in the axial direction, and generates a second frictional resistance torque Tf2 having the smallest value in this state, that is, the second screw 62. The combined screw 63 rotates relative to the second
The slider 65 moves rightward in the axial direction. For this reason,
The first screw 61 and the second screw 63 have the same twisting direction.

Due to this movement, the other end 7c of the release fork 7 is moved to the right and the pressing reaction force F decreases. When the pressing reaction force F reaches a predetermined value F1, Tf2 = Tf3,
When the pressing reaction force F further decreases, Tf2> Tf3. Then, this time, the third frictional resistance torque Tf3 becomes the minimum, so that the portion where the torque Tf3 is generated, that is, the contact surface between the other end 7c of the release fork 7 and the second slider 65 relatively rotates. However, even if this relative rotation is made,
The other end 7c of the release fork 7 does not move in the axial direction and balances when the pressing reaction force F = F1. Therefore, in the state where the motion conversion mechanism 60 is moved to the right and the main clutch MC is turned on, as shown in FIG.
The right end of the first slider 62 contacts the stopper 67, and the second slider 65 is automatically set to a position where the pressing reaction force F received from the other end 7c of the release fork 7 is F1.

That is, at the set position when the main clutch MC is engaged, the pressing reaction force F = F1 and the first slider 62 contacts the stopper 67. Here, the sensor shaft 58 of the stroke sensor 58
Since a is connected to the first slider 62 via the connecting plate 56, the position of the sensor shaft 58a at the set position is also constant. Therefore, the pressing reaction force F becomes F1, and the detection value of the stroke sensor 58 in a state where the main clutch MC is connected is always constant, and this state can be accurately detected.

The case where the friction disc 3 is not worn has been described above. Next, the case where this is worn will be described. FIG. 6 shows a state where the friction disc 3 is worn. As can be seen from this figure, when the friction disc 3 is worn, the pressing reaction force F at the time when the first slider 62 contacts the stopper 67.
Is larger than the predetermined value F1 and becomes, for example, F2. In such a state, the second frictional resistance torque Tf2 in the second screwing screw 63 is smaller than the third frictional resistance torque Tf3, so the second screwing screw 63 rotates and the first slider until Tf2 = Tf3. The second slider 65 is moved to the right with respect to 62.

The stroke of the friction disc 3 is corrected by the right movement of the second slider 65, and the correction is completed when the pressing reaction force F = F1. Note that FIG. 6 shows a state in which the wear correction is completed by such a right movement of the second slider 65. When the correction is completed in this way, the pressing reaction force F = F1, the first slider 62 contacts the stopper 67, and the main clutch MC is in the engaged state. As described above, even when the friction disc 3 is worn, the second slider 65 is moved by the amount of wear and the correction is automatically performed. Therefore, even in this case, the detection value of the stroke sensor 58 in the set state is always It will be constant. Therefore, even if the friction disc 3 is worn, the engagement state of the main clutch MC can be accurately detected based on the detection value of the stroke sensor 58.

As shown in FIGS. 8 and 9, the first
The motion converting mechanism 60 'can be configured by using a conventional screw as the screwing screw 61' instead of a ball screw. However, in this case, the first screw 6 for screwing
The flank angle α of 1 ′ is set smaller than the Flang angle β of the second screw 63 for screwing. That is, in this motion conversion mechanism, the angles are set so that α <β <γ,
As a result, in the region where the pressing reaction force F is F1 or more, T
f1 <Tf2 <Tf3, and the relationship shown in FIG. 7 is established. Further, in order to maximize Tf3, a friction member 69 having a large friction coefficient may be attached to either the tapered surface 7d of the other end 7c of the release fork 7 or the tapered surface 65a of the second slider 65. Further, the correction for the wear of the friction disc 3 is performed by the first slider 6
2 is performed by moving the second slider 65 to the right in the figure, and the second slider 65 does not move to the left. Therefore, the second screw 65 is attached to the second screw 65 with respect to the first slider. A one-way clutch mechanism may be provided that allows only the rightward rotation.

Next, the speed change mechanism connected to the main clutch MC, in which the engagement / disengagement operation control is performed in this manner, is shown in FIG.
A brief explanation will be given with reference to. As shown in FIG. 2, the main shaft 10 of this speed change mechanism has a first speed drive gear 11, a reverse drive gear 16, a second speed drive gear 12, a third speed drive gear 13, and a fourth speed drive in order from the left. A gear 14 and a fifth speed drive gear 15 are arranged. Here, the first speed drive gear 11, the reverse drive gear 16, and the second speed drive gear 12 are arranged so as to be coupled to the main shaft 10, and the third speed drive gear 13, the fourth speed drive gear 14, and the fifth speed drive gear are provided. A drive gear 15 is rotatably arranged on the main shaft 10.

A counter shaft 20 extending in parallel with the main shaft 10 is rotatably disposed below the main shaft 10. The counter shaft 20 includes an output gear 26, a first speed driven gear 21, a reverse driven gear 26, a second speed driven gear 22, a third speed driven gear 23, in this order from the left.
A fourth speed driven gear 24 and a fifth speed driven gear 25 are arranged. Here, the output gear 26 and the third speed driven gear 2
The third, fourth speed driven gear 24 and fifth speed driven gear 25 are arranged to be coupled to the counter shaft 20, and the first speed driven gear 21 and second speed driven gear 22 are rotatably arranged on the counter shaft 20. Has been done. The reverse driven gear 26 is coupled to the counter shaft 20 via the third hub 29.

First speed drive gear 11, second speed drive gear 1
The second, third speed drive gear 13, fourth speed drive gear 14 and fifth speed drive gear 15 are respectively a first speed driven gear 21, a second speed driven gear 22, a third speed driven gear 23 and a fourth speed driven gear. Is constantly meshed with the gear 24 and the fifth speed driven gear 25,
The first to fifth speed power transmission paths are formed by the gear trains meshing with each other.

A first hub 27 is mounted between the third speed drive gear 13 and the fourth speed drive gear 14 on the main shaft 10, and is opposed to the first hub 27 from the left and right sides to the third speed clutch gear 13a and the fourth speed gear. A clutch gear 14a is provided. Therefore, by moving the first sleeve 27a mounted on the first hub 27 so as to be movable in the axial direction to the left and right, the sleeve 27a is moved to the both clutch gears 1a and 1b.
The third speed drive gear 1 is engaged with one of 3a and 14a.
The third or fourth speed drive gear 14 can be connected to the main shaft 10. Although not shown, a synchronizing mechanism is arranged at the portions of both clutch gears 13a and 14a.

A second hub 28 having a second sleeve 28a is provided on the right side of the fifth speed drive gear 15, and the second sleeve 28a is moved leftward to move the fifth speed clutch gear 15 to the left.
The fifth speed drive gear 15 can be connected to the main shaft 10 by engaging with a. A synchronization mechanism is also arranged on the fifth side clutch gear 15a.

Similarly, a third hub 29 having a third sleeve 29a is mounted between the first speed driven gear 21 and the second speed driven gear 22 on the counter shaft 20. Move this third sleeve 29a left and right,
By engaging the first speed clutch gear 21a or the second speed clutch gear 22a with the third sleeve 29a, the first speed driven gear 21 or the second speed driven gear 22 can be coupled to the counter shaft 20.

A reverse shaft 17 is fixedly provided in parallel with the main shaft 10, and a reverse idler gear 18 is disposed on the reverse shaft 17 so as to be rotatable and movable left and right. The reverse idler gear 18 meshes with the reverse drive and driven gears 16 and 26 by moving leftward from the illustrated state, and a reverse power transmission path is formed by these gear trains.

In the transmission having the above structure, the first to third
By selectively moving the sleeves 27a, 28a, 29a and the reverse idler gear 18 in the axial direction,
It is possible to select one of the first to fifth speed power transmission paths and the reverse power transmission path to shift gears. This gear shifting operation is similar to that of the conventional manual transmission.
The shift forks engaged with the third sleeves 27a, 28a, 29a and the reverse idler gear 18 are moved in the axial direction.

However, in the manual transmission, the shift operation is performed by manually operating the shift lever, but in the automatic transmission AT, a shift operation motor (not shown) and
It has a select operation motor and the like, and these can be operated in the same manner as the conventional manual operation. During this gear shift operation, the operation of the main clutch MC is also performed. The engagement / disengagement control of the main clutch MC is performed even when the main clutch MC starts or stops. The engagement / disengagement control of the main clutch MC is performed by the engagement / disengagement operation control actuator 50 as described above. At that time, the stroke sensor 58 is used.
This engagement / disengagement control is performed based on the engagement state of the main clutch MC detected by.

[0041]

As described above, according to the present invention,
A first frictional resistance torque Tf1 that acts on relative rotation between the rotary drive shaft and the first slider when a reaction force of the engaging spring force is received from one end of the connecting means (release fork).
And a second frictional resistance torque Tf2 acting on the relative rotation of the first slider and the second slider, and a third frictional resistance torque Tf3 acting on the rotation of the second slider by friction with one end of the coupling means. And Tf1 <Tf2 <Tf3, and the first slider contacts the stopper formed on the housing at the end of the axial movement stroke associated with the rotation of the rotary shaft and becomes integral with the rotary shaft. Since it is configured to rotate, when the rotation converting shaft is rotated to move the motion converting means in the axial direction so as to engage the friction clutch, the first slider comes into contact with the stopper to prevent the engagement spring from rotating. The set state is reached when the force reaches the predetermined value F1.

In this case, even if the friction clutch wears, the second slider rotates relative to the first slider in correspondence with the wear amount, and the position correction is automatically performed, so that the first slider is always operated. The set state is brought into contact with the stopper and the reaction force of the engagement spring reaches a predetermined value F1. Therefore, the position of the first slider in the set state does not change regardless of whether the friction clutch is worn or not, and if the position of the first slider is detected, the engagement state of the friction clutch can always be detected accurately. Is possible.

[Brief description of drawings]

FIG. 1 is a sectional view showing a friction clutch engagement / disengagement control actuator according to the present invention and a main clutch operated by the actuator.

FIG. 2 is a skeleton diagram showing a power transmission path configuration of an automatic transmission having this main clutch.

FIG. 3 is a plan sectional view showing a motion conversion mechanism.

FIG. 4 is a front sectional view showing a motion conversion mechanism.

FIG. 5 is a cross-sectional view showing a friction clutch engagement / disengagement control actuator according to the present invention and a main clutch operated by the actuator.

FIG. 6 is a cross-sectional view showing a friction clutch engagement / disengagement control actuator according to the present invention and a main clutch operated by the actuator.

FIG. 7: Pressing reaction force F and first to third in the motion converting mechanism
It is a graph which shows the relationship with a frictional resistance torque.

FIG. 8 is a plan sectional view showing a different example of the motion conversion mechanism.

FIG. 9 is a front sectional view showing a different example of the motion conversion mechanism.

[Explanation of symbols]

 2 Diaphragm spring 3 Friction disk 6 Release bearing 7 Release fork 10 Main shaft 20 Counter shaft 50 Engagement control actuator 51 Electric motor 52 Rotation drive shaft 53 Electromagnetic brake 58 Stroke sensor 60 Motion conversion mechanism 62 First slider 65 Second slider

Claims (6)

[Claims] 1. A friction clutch that is frictionally engaged by receiving the engagement force of an engagement spring, comprising: an actuator that adjusts the engagement force of the engagement spring to control engagement / disengagement of the friction clutch. A rotary drive shaft rotatably supported on the rotary drive shaft, drive control means for controlling the rotary drive of the rotary drive shaft, motion converting means for converting the rotary motion of the rotary drive shaft into axial motion, and this motion converting means. And a coupling means for coupling the friction clutch, and the axial movement converted by the movement converting means is transmitted to the friction clutch via the coupling means to release the engagement force of the engagement spring. In the friction clutch engagement / disengagement control actuator, the motion conversion means is screwed onto the rotary drive shaft and is attached to the rotary drive shaft. A first slider adapted to be moved in the axial direction in response to relative rotation with respect to the first slider, and screwed onto the first slider and attached to the first slider in response to relative rotation with respect to the first slider. The second slider is configured to be relatively moved in the axial direction, and one end of the coupling means receives the reaction force of the engagement spring force and is axially pressed against the second slider to cause the second slider to move. A first frictional resistance torque that is connected to the slider and that acts on relative rotation between the rotary drive shaft and the first slider when receiving a reaction force of the engagement spring force applied from one end of the connecting means. T
f1, a second frictional resistance torque Tf2 that acts on relative rotation of the first slider and the second slider, and a first frictional action torque that acts on the rotation of the second slider by friction with one end of the connecting means. 3 Friction resistance torque Tf3 and Tf1 <Tf2 <Tf3, and the first slider is provided on a stopper provided on the rotary shaft at the end of the axial movement stroke accompanying the rotation of the rotary shaft. An actuator for friction clutch engagement / disengagement control, which is configured to abut and rotate integrally with the rotary shaft. 2. The first screw for screwing the first slider on the rotary drive shaft and the screw for second screw screwing the second slider on the first slider are both flank surfaces. The first flank angle α of the first screw for screwing is set to be smaller than the second flank angle β of the second screw for screwing. Actuator for disengagement control of friction clutch. 3. A first screw for screwing the first slider on the rotary drive shaft is a ball screw, and a screw for second screw screwing the second slider on the first slider. The friction clutch engagement / disengagement control actuator according to claim 1, wherein the flank surfaces are screws that contact each other. 4. A contact angle γ corresponding to a flank angle at a contact portion between the second slider and the connecting means is larger than a flank angle β of the second screw for screwing. The friction clutch engagement / disengagement control actuator according to. 5. A friction member having a large friction coefficient is provided on one of the second slider and the connecting means at a contact portion between the second slider and the connecting means. An actuator for engagement / disengagement control of a friction clutch according to any one of 1. 6. A stroke sensor for detecting the position of the first slider is connected to the first slider, and an engagement state of the friction clutch is detected based on a detection value of the stroke sensor. The actuator for engagement / disengagement control of a friction clutch according to any one of claims 1 to 5.