JP2007315548A - Clutch actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clutch actuator capable of preventing the locking of a worm wheel gear by an assist force of an assist spring acting in the direction restraining overshoot in the engagement of the clutch. <P>SOLUTION: The clutch actuator is provided with a motor 66, a shaft 68 having a worm gear 74 and driven by the motor, the worm wheel gear 76 meshed with the worm gear, and a rod 78 to which a rotation driving force of the worm wheel gear is transmitted by being converted to a linear driving force. The motor is drive-controlled, and the clutch can be engaged or released through the rod. The assist spring 98 is provided for assisting the rotation driving force of the worm wheel gear by drive-controlling the motor in the operation of the clutch from the engagement state to the release state. The assist force by the assist spring has a larger region from a touch point of the clutch to the clutch engagement side than an energizing force of an energizing means 92. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a clutch actuator capable of automatically engaging and releasing a clutch.

  A worm gear is provided on the output shaft of the motor, the worm wheel gear that meshes with the worm gear is rotated by the motor power, and the rotating motion of the worm wheel gear is converted into the straight motion of the push rod, and the engaged clutch is automatically Automobile clutch actuators for release are known.

  In such a clutch actuator, a clutch actuator provided with an assist spring is known in order to assist the driving force of a motor necessary for changing the posture of a clutch spring or the like of the clutch.

Responsiveness at the time of actuator operation is improved by the assist spring, and the motor and the actuator itself are miniaturized by using the assist spring.
JP 2004-116677 A JP 2002-221240 A

  In the conventional clutch actuator using the assist spring, the characteristic of the assist spring is always set lower than the clutch release characteristic in order to make the load direction when the actuator is operated constant.

  Therefore, in the return process, it is not possible to prevent the master cylinder from overshooting at an excessive speed even after passing the port open position due to the reaction force of the clutch, and the engagement of the worm gear and the worm wheel gear occurs, and the actuator does not move. Therefore, it is necessary to provide a buffer mechanism such as a spring for suppressing overshoot.

  In addition, in the conventional clutch actuator, the assist spring characteristics are not set in anticipation of the friction loss of each part of the actuator, so the assist force of the assist spring is weakened by the friction loss. There is a problem of not giving.

  The present invention has been made in view of the above points, and an object of the present invention is to improve the responsiveness at the time of clutch release, and the stroke of the return process of the master cylinder is excessively increased by the reaction force of the clutch. It is intended to provide a clutch actuator that suppresses overshooting and prevents the actuator from moving due to the engagement of the worm gear and the worm wheel gear.

  According to the first aspect of the present invention, the motor, the shaft having the worm gear, driven by the motor, the worm wheel gear meshing with the worm gear, and the rotational driving force of the worm wheel gear are converted into the straight driving force. A clutch actuator that is capable of engaging and releasing the clutch via the rod by controlling the drive of the motor, and generating a biasing force for engaging the clutch. And a rotational driving force in one direction of the worm wheel gear by the drive control of the motor when the clutch is operated from the engaged state to the released state against the urging force of the urging means. Transmitting and linearly moving the rod in the first direction, and the urging means during operation of the clutch from the disengaged state to the engaged state Driving force transmission means for allowing the rod to return in the direction opposite to the first direction by rotating the worm wheel gear in a direction opposite to the one direction by driving control of the motor while receiving an urging force; An assist spring that assists the rotational driving force of the worm wheel gear by the drive control of the motor when the clutch is operated from the engaged state to the released state, and the assist force by the assist spring is from the touch point of the clutch. A clutch actuator having a region larger than the biasing force of the biasing means on the clutch engagement side is provided.

  According to a second aspect of the invention, in the first aspect of the invention, in the region where the assist force by the assist spring is greater than the biasing force of the biasing means, the assist force of the assist spring is at least that of the worm wheel gear. There is provided a clutch actuator characterized in that a friction loss acting during rotational driving is larger than an urging force of the urging means.

  According to a third aspect of the invention, in the first aspect of the invention, the engagement position between the assist spring and the worm wheel gear is such that the assist force of the assist spring is changed from the engagement start position of the clutch. A clutch actuator is provided which is set to act on the worm wheel gear on the engagement side.

  According to the first aspect of the present invention, since the assist force region larger than the urging force of the urging means is provided, when releasing the clutch, the responsiveness can be improved and the clutch is engaged. In this case, since the assist force becomes resistance (load), overshoot at excessive speed can be suppressed, and the gear lock between the worm gear and the worm wheel gear can be obtained without adding a special buffer mechanism. It becomes possible to prevent.

  According to the second aspect of the present invention, the assist force of the assist spring is set such that at least the friction loss acting on the rotational drive of the worm wheel gear is larger than the urging force of the urging means. Such a load can be reliably reduced.

  According to the invention described in claim 3, since the engagement position between the assist spring and the worm wheel gear is appropriately set, the responsiveness at the time of clutch release is improved with a simple configuration, and the overshoot at the time of clutch engagement is suppressed. Therefore, it is possible to prevent gear lock between the worm gear and the worm wheel gear.

  First, the configuration of a manual transmission with an automatic clutch (manual transmission) suitable for application of the clutch actuator of the present invention will be described with reference to FIG. The clutch 8 is accommodated in the clutch housing 1, and the manual transmission includes a main shaft (input shaft) 4 and a counter shaft (output shaft) 6 arranged in parallel in the transmission case 2.

  The clutch 8 includes a flywheel 7 fixed to a crankshaft 3 of an engine (not shown) with bolts 5. The clutch cover 9 is fixed to the flywheel 7 with bolts 11.

  A pressure plate 13 is attached to the clutch cover 9 so as to be movable in the axial direction by a rivet (not shown). Further, a diaphragm spring 15 is attached to the clutch cover 13 so that an intermediate portion thereof is sandwiched by a pair of rings 17.

  The pressure plate 13 has an annular protrusion 13a, and the outer peripheral end of the diaphragm spring 15 is pressed against the annular protrusion 13a. That is, in the steady state, the diaphragm spring 15 is biased so that the outer peripheral end presses the annular protrusion 13a of the pressure plate 13 around the fulcrum sandwiched between the pair of rings 17 according to the lever principle.

  Near the end of the transmission main shaft 4, a hub 21 to which a clutch disk 19 is fixed is spline-coupled so as to be slidable in the axial direction and not relatively rotatable. Facings 23 are fixed to both front and rear surfaces of the clutch disk 19.

  In the illustrated clutch-on (clutch engaged) state, the pressure plate 13 is firmly pressed against the facing 23 of the clutch disk 19 by the biasing force of the diaphragm spring 15, and the rotation of the flywheel 7 is performed via the clutch disk 19. It is transmitted directly to the transmission main shaft 4.

  A release bearing 27 is slidably attached to a sleeve 25 formed integrally with the clutch housing 1. Reference numeral 29 denotes a slave cylinder of the clutch actuator, which is connected to a master cylinder described later via a pipe (not shown). 31 is a release fork.

  When the slave cylinder 29 is actuated by hydraulic pressure, the release bearing 25 slides rightward in the drawing via the release fork 31. As a result, the inner race of the release bearing 27 comes into contact with the inner peripheral end portion of the diaphragm spring 15, and the inner peripheral end portion of the diaphragm spring 15 is pushed rightward, whereby the diaphragm spring 15 rotates about its fulcrum. Thus, the biasing force of the diaphragm spring 15 to the pressure plate 13 is released.

  As a result, the pressing force of the pressure plate 13 against the facing 23 of the clutch disk 19 is released, the clutch is turned off, and transmission of the rotational force of the crankshaft 3 to the transmission main shaft 4 via the clutch 8 is interrupted.

  The main shaft 4 is connected to an engine (not shown) via a clutch 8, and the counter shaft 6 is connected via a final drive gear 12 to a ring gear (final driven gear) 14 of a differential device 10 that transmits power to left and right drive wheels of the vehicle. It is connected.

  Between the main shaft 4 and the counter shaft 6, as a forward shift stage, the first speed stage G 1, the second speed stage G 2, the third speed stage G 3, the fourth speed stage G 4, the fifth speed stage G 5 and 6, in order from the clutch 8 side. A speed stage G6 is arranged. Further, a reverse gear GR is arranged between the first gear G1 and the second gear G2, and this transmission performs a shift of six forward gears and one reverse gear.

  The first speed stage G1 includes a drive gear 16 fixedly attached to the main shaft 4 and a driven gear 18 rotatably attached to the countershaft 6, and the drive gear 16 and the driven gear 18 mesh with each other.

  The second speed stage G2 includes a drive gear 20 fixedly attached to the main shaft 4 and a driven gear 22 rotatably attached to the counter shaft 6, and the drive gear 20 and the driven gear 22 mesh with each other.

  The third speed stage G3 includes a drive gear 24 that is rotatably attached to the main shaft 4 and a driven gear 26 that is fixedly attached to the counter shaft 6. The drive gear 24 and the driven gear 26 mesh with each other.

  The fourth speed stage G4 includes a drive gear 28 that is rotatably attached to the main shaft 4 and a driven gear 30 that is fixedly attached to the countershaft 6. The drive gear 28 and the driven gear 30 mesh with each other.

  The fifth speed stage G5 includes a drive gear 32 rotatably attached to the main shaft 4 and a driven gear 34 fixedly attached to the counter shaft 6. The drive gear 32 and the driven gear 34 mesh with each other.

  The sixth speed stage G6 includes a drive gear 33 that is rotatably attached to the main shaft 4 and a driven gear 35 that is fixedly attached to the counter shaft 6. The drive gear 33 and the driven gear 35 mesh with each other.

  Switching of each gear stage is performed by three synchromesh mechanisms 36, 38, and 40. The first synchromesh mechanism 36 is provided on the counter shaft 6 between the first speed driven gear 18 and the second speed driven gear 22.

  The second synchromesh mechanism 38 is provided on the main shaft 4 between the third speed drive gear 24 and the fourth speed drive gear 28. The third synchromesh mechanism 40 is provided on the main shaft 4 between the fifth speed drive gear 32 and the sixth speed drive gear 33.

  Except at the time of a shift change, the power of the main shaft 4 is transmitted to the countershaft 6 through the gear stage selected by the operation of the synchromesh mechanisms 36-40. After being decelerated by the final reduction ratio of the final drive gear 12 and the final driven gear 14, it is transmitted to the differential device 10. As a result, the drive wheel rotates in the forward direction.

  On the other hand, at the time of retreat, all the synchromesh mechanisms 36 to 40 are set to the neutral state. The reverse drive gear 42 fixedly attached to the main shaft 4 and the reverse drive gear 44 formed integrally with the synchromesh 36 a of the synchromesh mechanism 36 are not directly meshed with each other but are in a line. ing.

  In this state, the reverse idler gear 48 rotatably and slidably attached to the reverse shaft 46 is slid in the axial direction on the reverse shaft 46 by the reverse fork 60, and the reverse drive gear 42 and the reverse driven gear 44 are Engage with both sides.

  As a result, the power of the main shaft 4 is transmitted to the counter shaft 6 via the reverse drive gear 42, the reverse idler gear 48 and the reverse driven gear 44. During reverse, power is transmitted to the countershaft 6 via the reverse idler gear 48. Therefore, the rotation direction of the countershaft 6 is opposite to that during forward movement, and the drive wheels rotate in the reverse direction.

  In FIG. 1, in order to clarify the structures of the reverse shaft 46 and the reverse idler gear 48, these are shown above the reverse gears 42, 44. Note that it is in a position where it can mesh with both gears 42, 44.

  The operation of the synchromesh mechanisms 36, 38, 40 described above may be manual or automatic. In the case of manual operation, the synchromesh mechanisms 36, 38, and 40 are selectively slid through the shift fork by operating the shift lever.

  In the case of automatic, an actuator such as a motor is driven based on a shift command on the vehicle side, and the synchromesh mechanisms 36, 38, and 40 are selectively slid. In this case, since the operation of the clutch 8 and the transmission is automated, an automated manual transmission (automatic MT) is obtained.

  Hereinafter, the clutch actuator 62 according to the embodiment of the present invention will be described in detail with reference to FIGS. FIG. 2 is a longitudinal sectional view of the embodiment of the present invention.

  A motor 66 capable of normal rotation and reverse rotation is attached to the housing 64 of the clutch actuator 62. A shaft 68 that is rotatably supported by a pair of bearings 70 and 72 is connected to the output shaft of the motor 66. A worm gear 74 is formed on the shaft 68.

  The worm gear 74 meshes with a worm wheel gear 76 that is rotatably supported in the housing 64. The worm gear 74 and the worm wheel gear 76 constitute a speed reduction mechanism. A pin 80 protrudes from the worm wheel gear 76. A push rod 78 is slidable in the left-right direction in the figure.

  The push rod 78 has a step 78a, and a piece member 82 is press-fitted, for example, so that one end 82a abuts on the step 78a. However, the attachment of the piece member 82 to the push rod 78 is not limited to press-fitting. After the piece member 82 is inserted into the push rod 78, it may be fixed by welding or the like.

  The piece member 82 has a pair of protrusions 84a and 84b integrally. A pin 80 protruding from the worm wheel gear 76 is inserted between the protrusions 84a and 84b.

  A master cylinder 86 is attached to the housing 64. A piston 88 is accommodated in the master cylinder 86 so as to be slidable left and right. The piston chamber 90 is filled with oil and a return spring 92 is disposed to urge the piston 88 rightward in the drawing. ing.

  The piston chamber 90 of the master cylinder 86 is connected to the slave cylinder 29 via an oil passage 94 and a hydraulic pipe (not shown). By sliding the piston 88 left and right, the piston chamber 90 is selectively communicated to a reserve tank (not shown) via an oil passage 96.

  Reference numeral 98 denotes an assist spring, and an engagement point 98a between the assist spring 98 and the worm wheel gear 76 is set to advance by a predetermined angle θ at the illustrated port open position of the master cylinder 86. Reference numeral 98 b denotes an engagement point between the assist spring 98 and the housing 64.

  Conventionally, at the port open position, the engagement point between the assist spring 98 and the worm wheel gear 76 is set on a straight line passing through the center of the worm wheel gear 76.

  In the state shown in FIG. 2, the piston 88 of the master cylinder 86 is slid rightward by the hydraulic pressure in the piston chamber 90 and the urging force of the return spring 92, and the piston chamber 90 is connected to the reserve tank via the oil passage 96. The port open position connected to is shown.

  In this port open position, the other end (right end) 82b of the piece member 82 abuts against the inner surface of the housing 64, or the right end 82b of the piece member 82 is disposed with a slight gap.

  Next, with reference to FIGS. 3 and 4, the spring characteristics of the assist spring 98 according to the embodiment of the present invention compared to the prior art will be described. FIG. 3 shows the assist spring characteristics of the clutch actuator 62 of the above-described embodiment of the present invention. Reference numeral 102 denotes a clutch release characteristic, 104 denotes a spring characteristic of a conventional assist spring, and 110 denotes a spring characteristic of the assist spring according to the embodiment of the present invention.

  The origin indicates a port open position, reference numeral 108 indicates a clutch release operating range, and 106 indicates a point at which the clutch 8 starts to have torque transmission capacity, that is, a touch point of the clutch 8.

  In a conventional clutch actuator having an assist spring, the assist spring characteristic is always set lower than the clutch release characteristic 102 over the entire release stroke as indicated by a broken line 104 in order to make the load direction when the actuator is operated constant.

  For this reason, in the return process of the master cylinder, it is not possible to suppress overshooting at an excessive speed even if the master cylinder passes the port open position due to the clutch reaction force, and the worm gear and the worm wheel gear are caught. There is a risk that the actuator may become immobile.

  In the present embodiment, the engagement position 98a of the assist spring 98 attached to the worm wheel gear 76 is advanced by a predetermined angle θ at the port open position shown in FIG. 2, and the load of the assist spring 98 is set to be large. By doing so, the clutch release characteristic and the assist characteristic of the assist spring 98 are optimized.

  That is, the assist spring characteristic 110 is set so that the assist force by the assist spring 98 has a region larger than the release characteristic 102 in the overshoot range 112.

  As is apparent from FIG. 3, in the clutch release operating range 108, the spring force of the assist spring 98 becomes an assist force as indicated by reference numeral 114, and the spring force becomes a reaction force (resistance) as indicated by reference numeral 116 at the time of overshoot. .

  As described above, since the engagement position between the assist spring and the worm wheel gear is advanced by the predetermined angle θ at the port open position and the assist force region larger than the release characteristic 102 is provided, when the clutch 8 is released. In addition to improving the responsiveness, since the assist force becomes resistance (load) when the clutch 8 is engaged, overshoot can be suppressed, and the worm gear 74 and the worm wheel gear 76 can be suppressed. The gear lock between the two can be prevented.

  FIG. 4 shows assist spring characteristics of another embodiment of the present invention. In the present embodiment, the spring force (load) is set to be large in consideration of the loss due to the friction of each part of the clutch actuator 62 in the setting assist spring characteristic 118.

  As described above, when the set assist spring characteristic is set to be large in consideration of the friction loss, the actual assist torque on the worm wheel gear 76 has a characteristic as indicated by a broken line 120.

  The actual assist torque 120 on the worm wheel gear 76 can be set so as to have an assist force region larger than the release characteristic 102 in the overshoot range in the same manner as the embodiment shown in FIG.

  According to the present embodiment, since the friction loss that causes at least the assist force of the assist spring 98 to act on the rotational drive of the worm wheel gear 76 is set to be larger than the release characteristic 102, the load on the motor in the drive control by the motor 66 is set. It can be reliably reduced.

  Hereinafter, the operation of the clutch actuator 62 shown in FIG. 2 will be described. When the motor 66 is energized based on the vehicle-side shift command, the motor 66 rotates (this is assumed to be normal rotation), and the worm gear 74 is rotated by driving the motor 66.

  The rotation of the worm gear 74 is transmitted to the worm wheel gear 76 meshing with the worm gear 74, and the worm wheel gear 76 is decelerated to rotate. At this time, since the assist spring 98 is advanced by a predetermined angle θ and attached to the worm wheel gear 76, the assist spring 98 assists the rotation of the worm wheel gear 76, and the responsiveness can be improved.

  When the worm wheel gear 76 rotates in the direction of the arrow 77 (counterclockwise direction), the pin 80 pushes the protrusion 84a of the piece member 82, whereby the rotation of the worm wheel gear 76 is converted into the linear motion of the push rod 78 and pushed. The rod 78 is moved leftward in the figure.

  As a result, the left end 78 b of the push rod 78 pushes the piston 88 of the master cylinder 86 leftward, and hydraulic pressure is generated in the piston chamber 90. This hydraulic pressure is transmitted to the slave cylinder 29 shown in FIG. 1 through an oil passage 94 and a hydraulic pipe, and the piston rod 29a pushes the upper end of the release fork 31 leftward in FIG.

  As a result, the lower end of the release fork 31 is moved in the right direction, the release bearing 27 is slid in the right direction, the inner race of the release bearing 27 comes into contact with the inner peripheral end of the diaphragm spring 15, and the diaphragm spring 15 By pushing the inner peripheral end in the right direction, the diaphragm spring 15 rotates about its fulcrum, and the urging force of the diaphragm spring 15 to the pressure plate 13 is released.

  As a result, the pressing force of the pressure plate 13 against the facing 23 of the clutch disk 19 is released, the clutch is turned off, and transmission of the engine rotational force to the transmission main shaft 4 via the clutch 8 is interrupted.

  When the clutch is engaged, the release bearing 27 slides to the left by the urging force of the diaphragm spring 15 and pushes the piston of the slave cylinder 29 in the compression direction via the release fork 31, so that the piston chamber 90 of the master cylinder 86 enters the piston chamber 90. Pressure oil is returned.

  The piston 88 of the master cylinder 86 is slid rightward in FIG. 2 by the hydraulic pressure generated by the pressure oil and the urging force of the return spring 92. At this time, an electric current is passed through the motor 66 in the reverse direction to that during forward rotation to reverse the motor 66 and rotate the worm wheel gear 76 in the clockwise direction while controlling the rotation speed.

  That is, the worm wheel gear 76 is reversely rotated by the drive control of the motor 66 while receiving the thrust force in the right direction of the push rod 78 generated by the hydraulic pressure and the urging force of the return spring 92 at the pin 80.

  As a result, the push rod 78 is returned at a speed corresponding to the rotational speed of the worm wheel gear 76, overshoots past the clutch release operating range 108, and the right end 82 b of the piece member 82 contacts the inner surface of the housing 64. In position, the push rod 78 is stopped.

  In the present embodiment, since the assist spring 98 is attached to the worm wheel gear 76 with a predetermined angle θ advanced at the port open position, the assist spring 98 becomes a resistance (load) at the time of overshoot. In addition, the impact of the piece member 82 upon collision with the inner surface of the housing 64 can be mitigated, and gear lock between the worm gear 74 and the worm wheel gear 76 can be prevented.

It is a longitudinal cross-sectional view of the manual transmission which has an automatic clutch which can apply the clutch actuator of this invention. It is a longitudinal section of the embodiment of the present invention. It is a figure which shows the assist spring characteristic of embodiment of this invention. It is a figure which shows other embodiment of an assist spring characteristic.

Explanation of symbols

8 Clutch 27 Release bearing 29 Slave cylinder 31 Release fork 62, 62A Clutch actuator 66 Motor 74 Worm gear 76 Worm wheel gear 78 Push rod 80 Pin 82 Piece member 84, 84a, 84b Projection 86 Master cylinder 88 Piston 98 Assist spring

Claims (3)

A motor,
A shaft having a worm gear and driven by the motor;
A worm wheel gear meshing with the worm gear;
A rod that converts the rotational driving force of the worm wheel gear into a straight driving force and transmits it,
In the clutch actuator that enables engagement and disengagement of the clutch via the rod by controlling the driving of the motor,
Biasing means for generating a biasing force for engaging the clutch;
When the clutch is operated from the engaged state to the released state against the urging force of the urging means, the rotational driving force in one direction of the worm wheel gear by the drive control of the motor is transmitted to the rod. The rod is linearly moved in the first direction, and the worm wheel gear is moved in the one direction by driving control of the motor while receiving the urging force of the urging means when the clutch is operated from the released state to the engaged state. Driving force transmitting means for rotating in the opposite direction to allow the rod to return in the opposite direction to the first direction;
An assist spring that assists the rotational driving force of the worm wheel gear by the drive control of the motor when the clutch is operated from the engaged state to the released state;
The clutch actuator according to claim 1, wherein an assist force by the assist spring has a region larger than an urging force of the urging means on a clutch engagement side from a touch point of the clutch.   In a region where the assist force by the assist spring is larger than the biasing force of the biasing means, the assist force of the assist spring is at least a friction loss acting when the worm wheel gear is driven to rotate by the biasing force of the biasing means. The clutch actuator according to claim 1, wherein   The engagement position between the assist spring and the worm wheel gear is set so that the assist force of the assist spring acts on the worm wheel gear on the engagement side of the clutch from the engagement start position of the clutch. The clutch actuator according to claim 1.

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