JP2008057612A - Actuator for clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize an actuator and save power by reducing a work load of a power source for the actuator. <P>SOLUTION: The actuator for a clutch is provided with a power source 32, rotors 35, 50 driven by the power source 32, an output rod 31 connected to the rotors 35, 50 to relatively rotate, and an assist spring 90 with one end supported by a housing 33 and the other end supported by the rotors 35, 50 to relatively rotate and assist rotation of the rotors 35, 50. In an actuator 30 for engagement operation, disengagement operation, and semi-engagement operation of the clutch are carried out by movement of the output rod 31, the assist spring 90 is composed such that a dense portion with a small spring constant deforms during a first half of deflection, and a coarse part with a large spring constant deforms during a latter half of deflection. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a clutch actuator for connecting and disconnecting a clutch.

  There is known a system in which an actuator is attached to an existing manual transmission, and a series of shift operations (clutch connection / disconnection, gear shift, selection) are automatically performed according to a driver's intention or a vehicle state.

  In such a system, a clutch actuator for connecting / disconnecting and half-connecting a clutch includes a driving force source such as an electric motor and an output rod in order to change the posture of a diaphragm spring or the like. The output rod stroke requires a large force that leads to an increase in the size of the drive source. In order to suppress the required drive force, and to maintain the stroke position even when the motor is not energized, a worm gear is used. Is slowing down. In addition, a mechanism called assist spring for assisting the stroke of the output rod is provided.

  As conventional techniques of such a clutch actuator, a power source 32, a rotating body 35 driven to rotate by the power source 32, a driven rotating body 50 connected to the rotating body 35 and rotating integrally therewith, and the driven An output rod 31 that is coupled to the rotating body 50 so as to be relatively rotatable. In the clutch actuator 30 that engages and disengages the clutch by moving the output rod 31, the rotating body 35 and the driven body are provided. A connecting member 35b is arranged between the rotating body 50 and the rotating body 35 and the driven rotating body 50 are not arranged in the same plane. One end of the driven rotating body 50 is supported by the housing 33. The assist spring 36 assists the rotation of the driven rotator 50, and the assist spring 36 is pivotally supported between the rotator 35 and the driven rotator 50. A support portion 35e protruding from the support member 35b and a support portion 38d protruding from the housing 33 are supported so as to be rotatable according to the rotation of the driven rotating body 50 ( (See Patent Document 1 and FIG. 10). According to this, the capacity required for the power source 32 is reduced, so that the power source 32 and the actuator 30 itself can be reduced in size, and further, mountability and versatility can be improved. Is.

JP 2004-301238 A

  However, since the conventional clutch actuator 30 uses a coil spring having an equal pitch between the spirals when the assist spring 36 is in a free state (see FIG. 10B), the spring constant is constant from the initial stage to the late stage. there were. Therefore, the waveform of the value of the load that the output rod 31 must output, which is the load (clutch cover load) applied to the output rod 31 when the output rod 31 makes a stroke, and the assist load that the assist spring 36 can assist. There are many areas where the value waveform deviates greatly (see FIG. 11), and the work amount of the power source 32 (the load that must be generated by the power source multiplied by the stroke amount). There is a possibility that the load increases and the power consumption of the power source 32 cannot be reduced. In addition, when the work load of the power source 32 is large, it is necessary to use a power source 32 having a large load, and there is a possibility that the size cannot be reduced. Further, if the workload of the power source 32 is heavy, the stroke operating speed of the output rod 31 may be reduced. In particular, when the conventional clutch actuator 30 is used in a large vehicle, the above-described problem becomes significant.

  The main problem of the present invention is to reduce the amount of work of the power source to achieve miniaturization, low power consumption, and the like.

  In a viewpoint of the present invention, a power source, a rotating body that is rotationally driven by the power source, an output rod connected to the rotating body, one end supported by a housing, and the other end rotating the rotating body An assist spring supported so as to assist, and a clutch actuator that performs clutch engagement / disengagement and semi-junction operation according to the stroke of the output rod, wherein the assist spring is rotated according to the stroke of the output rod. When the body is bent as the body rotates, a portion with a small spring constant is deformed in the first half of bending, and a portion with a large spring constant is deformed in the second half of bending.

  In the clutch actuator according to the aspect of the invention, it is preferable that the assist spring has a smaller pitch of a part of the coil than a pitch of the other part in a free state.

  In the clutch actuator according to the present invention, the coil spring deforms a pitch dense portion having a small spring constant in the first half of bending, and after the dense portion of the pitch is in close contact, the pitch rough portion having a large spring constant is deformed in the second half of bending. It is preferable to be configured to do so.

  In the clutch actuator of the present invention, the assist spring includes a first coil spring having an equal pitch, a second coil spring that is shorter than a length of the first coil spring and smaller than a diameter of the first coil spring, The first coil spring has one end supported by the housing and the other end supported by the rotating body so as to be relatively rotatable, and the second coil spring is an inner peripheral side of the first coil spring. It is preferable to arrange | position.

  According to the present invention, the assist region can be expanded according to the curve of the clutch load, the work amount of the power source can be reduced, and the power consumption of the power source can be reduced. Further, the power source can be reduced in size by reducing the work amount of the power source. Furthermore, since the work amount of the power source is reduced, the stroke operating speed of the output rod can be improved, and in particular, quickness (reactivity) when the clutch is released can be improved. In particular, when used in a large vehicle, the above-described effects become significant.

(Embodiment 1)
A clutch actuator according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view schematically showing a configuration of a clutch device to which a clutch actuator according to Embodiment 1 of the present invention is applied. FIG. 2 is a front view schematically showing a configuration in which a part of the clutch is cut away in the clutch device to which the clutch actuator according to the first embodiment of the present invention is applied. 3A is a front view schematically showing the configuration of the clutch actuator according to the first embodiment of the present invention, and FIG. 3B is a sectional view of the assist spring in a free state. 4 is a cross-sectional view taken along the line XX ′ in FIG. 3 schematically illustrating the clutch actuator according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view taken along the line YY ′ of FIG. 4 schematically illustrating the clutch actuator according to the first embodiment of the present invention.

  This clutch device includes a friction clutch 20 disposed between an engine (not shown) and a transmission (not shown), and an actuator 30 for operating the friction clutch 20. The actuator 30 is driven and controlled by a control device (not shown), so that the engagement state of the friction clutch 20 changes.

  The friction clutch 20 includes, as main components, a flywheel 21, a clutch cover 22, a clutch disk 23, a pressure plate 24, a diaphragm spring 25, a release bearing 26, a release fork 27, and a transmission case 11a. And a pivot support member 28 fixed to the head. Note that the pressure plate 24, the diaphragm spring 25, and the like are integrally assembled with the clutch cover 22, and may be referred to as a clutch cover assembly.

  The flywheel 21 is a disc made of cast iron, is bolted to the crankshaft 10a of the engine, and rotates integrally with the crankshaft 10a.

  The clutch cover 22 has a substantially cylindrical shape, and includes a cylindrical portion 22a, a flange portion 22b formed on the inner peripheral side of the cylindrical portion 22a, and a plurality formed at equal intervals in the circumferential direction on the inner peripheral edge of the cylindrical portion 22a. The fulcrum forming part 22c. The clutch cover 22 is bolted to the flywheel 21 at the outer peripheral portion of the cylindrical portion 22 a and rotates integrally with the flywheel 21.

  The clutch disk 23 is a friction plate that transmits power of an engine (not shown) to a transmission (not shown). The clutch disk 23 is disposed between the flywheel 21 and the pressure plate 24 and is splined to the transmission input shaft at the center so that it can move in the axial direction with respect to the transmission input shaft. ing. Clutch facings 23a and 23b made of a friction material are fixed to both surfaces of the outer peripheral portion of the clutch disk 23 by rivets. The clutch disk 23 has a function of buffering engine torque fluctuations.

  The pressure plate 24 presses the clutch disc 23 toward the flywheel 21 and sandwiches it between the flywheel 21 and causes the clutch disc 23 to frictionally engage with the flywheel 21 to rotate integrally. The pressure plate 24 is connected to the clutch cover 22 by a strap 24 a so as to rotate with the rotation of the clutch cover 22. The pressure plate 24 is assembled with an adjusting mechanism 80 that can change the axial distance between the diaphragm spring 25 and the pressure plate 24. The adjustment mechanism 80 is a mechanism member that forms a force transmission path between the pressure plate 24 and the diaphragm spring 25, and compensates for changes in the load characteristics of the clutch due to wear of the clutch facings 23a and 23b. Further, instead of the adjustment mechanism 80, a ring-shaped member that makes the axial distance between the diaphragm spring 25 and the pressure plate 24 constant may be used. Such a ring-shaped member is integrated with the pressure plate 24. It may be.

  The strap 24a is composed of a plurality of laminated thin leaf spring materials. As shown in FIG. 2, one end of the strap 24a is fixed to the outer peripheral portion of the clutch cover 22 by a rivet R1, and the other end is fixed. The rivet R2 is fixed to a protrusion provided on the outer periphery of the pressure plate 24. As a result, the strap 24a applies an urging force in the axial direction to the pressure plate 24 so that the pressure plate 24 can be separated from the flywheel 21.

  As shown in FIGS. 1 and 2, the diaphragm spring 25 includes a plurality (12) of resilient plate members (hereinafter referred to as “lever members”) arranged radially along the inner periphery of the cylindrical portion 22 a of the clutch cover 22. 25a "). As shown in FIG. 1, each lever member 25a is sandwiched between fulcrum forming portions 22c of the clutch cover 22 via a pair of ring-shaped fulcrum members 25b and 25c arranged on both sides in the axial direction of each lever member 25a. ing. The lever member 25a acts so that the outer end presses the adjusting mechanism 80 toward the pressure plate 24, and the inner end acts so as to press the release bearing 26 toward the release fork 27. The lever member 25a is pivoted about the fulcrum members 25b and 25c with respect to the clutch cover 22 when the inner end portion is pressed against the flywheel 21 by the release bearing 26, and the outer end portion is moved from the adjustment mechanism 80. Operate to leave. By such an operation, the friction engagement between the clutch disk 23 and the flywheel 21 and the operation for releasing it can be performed.

  The release bearing 26 is slidably supported by a support sleeve 11b supported by the transmission case 11a so as to surround the outer periphery of the input shaft of the transmission. The release bearing 26 constitutes a force point portion 26a for pushing the inner end portion (center portion of the diaphragm spring 25) of the lever member 25a toward the flywheel 21 side.

  The release fork 27 is for sliding the release bearing 26 in the axial direction in accordance with the operation of the actuator 30. One end of the release fork 27 is in contact with the release bearing 26, and the other end is in contact with the pressing portion at the tip of the output rod 31 of the actuator 30 at the contact portion 27a. The release fork 27 is assembled to the pivot support member 28 by a spring 27c fixed to the transmission case 11a, and swings about the pivot support member 28 at a substantially central portion 27b of the release fork 27. It has become.

  The actuator 30 applies a force for changing the engagement state of the clutch disk 23 to the diaphragm spring 25 by moving the output rod 31 forward and backward. The actuator 30 includes an electric motor 32 as a DC drive power source, a housing 33 that forms a support portion 38d, a rotary shaft 34 that is rotationally driven by the electric motor 32, and a rotating body that is meshed with the rotary shaft 34. Worm wheel 35, sub-wheel 50 as a driven rotor, coil spring-like assist spring 90, and housing cover 37.

  The electric motor 32 rotationally drives the rotating shaft 34 in both forward and reverse directions by power supply from a control device (not shown). The housing 33 is fixed at an appropriate position of the vehicle and supports the electric motor 32. The housing 33 has a bottomed accommodating portion 38, and the rotating shaft 34 protrudes leftward in FIG. 3A from one side of the side wall 38a forming the accommodating portion 38. The proximal end side (left side in FIG. 5) and the distal end side (right side in FIG. 5) of the rotation shaft 34 are pivotally supported by the housing 33. A worm portion 34 a is formed at a substantially intermediate portion in the axial direction of the rotation shaft 34.

  As shown in FIG. 4, a substantially bottomed cylindrical bearing portion 38 c is formed on the bottom wall 38 b of the accommodating portion 38, and the worm wheel 35 is pivotally supported. More specifically, the worm wheel 35 includes a substantially fan-shaped wheel portion 35a and a shaft portion 35b serving as a connecting member that penetrates the central portion of the wheel portion 35a. The worm wheel 35 is pivotally supported by the housing portion 38 (bottom wall 38b) by inserting one side (left side in FIG. 4) of the shaft portion 35b into the bearing portion 38c via a bush. A gear portion 35c that meshes with the worm portion 34a of the rotating shaft 34 is formed on the outer peripheral surface of the wheel portion 35a. Therefore, when the rotary shaft 34 is driven to rotate, the worm wheel 35 rotates in conjunction with this.

  On the other hand, the housing cover 37 also has a bottomed accommodating part 51 like the housing 33, and the output rod 31 protrudes leftward in FIG. 3 from one side of the side wall 51a forming the accommodating part 51. Further, a bearing portion 51c is formed on the bottom wall 51b of the housing portion 51, and the other side (right side in FIG. 4) of the shaft portion 35b of the worm wheel 35 is inserted into the bearing portion 51c via a bush. Thus, it is pivotally supported by the accommodating portion 51 (bottom wall 51b). The shaft portion 35b of the worm wheel 35 passes through the center portion of the sub wheel 50, and the worm wheel 35 and the sub wheel 50 are integrally formed.

  In FIG. 3, a substantially cylindrical rod support pin 50 d extending to one side (right side in FIG. 4) is fixed to the outer peripheral portion on the upper side with respect to the rotation center of the sub wheel 50. Yes. On the other hand, from one side of the side wall 51a of the accommodating part 51, the output rod 31 protrudes leftward in FIG. 3 corresponding to the rod support pin 50d. The rod support pin 50d supports the output rod 31 so that the end of the output rod 31 on the side opposite to the distal end contacting the proximal end (release fork) 27 is inserted. Therefore, the output rod 31 is coupled to the worm wheel 35 via the sub wheel 50 using a space formed between the sub wheel 50 and the bottom wall 51 b of the housing portion 51. When the worm wheel 35 rotates, the output rod 31 moves forward and backward with respect to the housing 33. For example, when the worm wheel 35 rotates in the clockwise direction in FIG. 3, the output rod 31 moves to the right so as to reduce the stroke (the clutch stroke ST increases). On the other hand, when the worm wheel 35 rotates counterclockwise in FIG. 3, the output rod 31 moves to the left so as to increase its stroke. The rotation range of the worm wheel 35 is set so that the increase / decrease of the clutch stroke ST is uniquely determined corresponding to the rotation direction.

  Further, in FIG. 3, a support as a substantially cylindrical support member that extends between the worm wheel 35 and the sub wheel 50 substantially parallel to the axial direction at the outer peripheral portion that is on the upper side with respect to the rotation center of the worm wheel 35. The pin 35e is fixed, and both ends of the support pin 35e are supported. On the other hand, on one side (upper side in FIG. 3) of the side wall 38 a of the housing portion 38, a support portion 38 d that protrudes inward corresponding to the support pin 35 e is formed in a recess provided in the housing 33. And the assist spring 90 is supported in the aspect latched by these support pins 35e and the support part 38d fundamentally.

  More specifically, a support base 41 is provided on the support pin 35e side. The support base 41 includes a pedestal portion 41a having a recessed central portion corresponding to the support pin 35e, and is slidably locked to the support pin 35e in the pedestal portion 41a. The support base 41 includes a positioning pin 41b as a positioning portion that protrudes from the base portion 41a on the opposite side to the support pin 35e. The positioning pin 41 b has an outer diameter substantially equal to the inner diameter of the assist spring 90 and positions one end of the assist spring 90.

  On the other hand, a similar support base 42 is also provided on the support portion 38d side. The support base 42 has a pedestal portion 42a having a recessed central portion corresponding to the support portion 38d, and is slidably locked to the support portion 38d in the pedestal portion 42a. Further, the support base 42 includes a positioning pin 42b as a positioning part that protrudes from the pedestal part 42a on the side opposite to the support part 38d. The positioning pin 42b also has an outer diameter substantially equal to the inner diameter of the assist spring 90, and positions the other end of the assist spring 90.

  As shown in FIG. 3B, the assist spring 90 is an unequal pitch coil spring configured so that the pitch at both ends of the coil is dense and the center pitch is rough in a free state. The assist spring 90 mainly deforms at both ends (dense portions) with a small spring constant in the first half of the bending, and after the two ends are in close contact, the central portion (coarse portion) with a large spring constant mainly deforms in the second half of the bending. (See FIG. 6). The assist spring 90 is supported between the support bases 41 and 42 in a state where the positioning pins 41b and 42b are inserted. The assist spring 90 is accommodated and supported using a space formed between the wheel portion 35 a of the worm wheel 35 and the sub wheel 50. When the worm wheel 35 rotates, the assist spring 90 changes its deflection amount and inclination in conjunction with the worm wheel 35.

  Here, on the bottom wall 38b, a regulating wall 38e is formed as a regulating portion that constitutes a stop member that regulates the movement of the assist spring 90 in conjunction with the rotation of the worm wheel 35 (see FIG. 3A). . When the worm wheel 35 rotates to a predetermined position in the clockwise direction, the regulating wall 38e is larger than the assist spring 90 supported by the support base 41 by the contact of the opposing end surfaces 41c on both sides of the support base 41 (pedestal portion 41a). Regulate the movement of In addition, a guide groove 38f is formed as a permissible portion that constitutes a stop member that is recessed along the rotation locus of the support pin 35e at a position facing the support pin 35e of the restriction wall 38e. Therefore, even when the movement of the assist spring 90 is restricted by the restriction wall 38e, the support pin 35e can move within a predetermined range along the guide groove 38f. Only the worm wheel 35 further rotates in a state where the support base 41 that supports the assist spring 90 is left at the position of the regulation wall 38e. The assist spring 90 is disposed on the upper right side in FIG. 3A with respect to the rotation center of the worm wheel 35 in correspondence with the support pin 35e in the movement range until it is regulated by the regulation wall 38e. The assist spring 90 is compressed and supported between the support bases 41 and 42, and has an urging force in a direction to rotate the worm wheel 35 in the clockwise direction in FIG. Therefore, the assist spring 90 assists the worm wheel 35 to rotate clockwise in FIG. 3A, that is, to move the output rod 31 to the right (to increase the clutch stroke ST). .

  Next, a relative operation of the assist spring 90 and the output rod 31 of the clutch actuator according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a schematic diagram for explaining the movement of the assist spring of the clutch actuator according to the first embodiment of the present invention.

  Referring to FIG. 7A, the assist spring 90 is in a state where the dense portion and the rough portion are compressed. When the sub-wheel 50 rotates clockwise from this state, as shown in FIG. 7B, the rough portion of the assist spring 90 is extended, and the assist spring 90 is swung to the right side of the drawing, and the output rod 31 is moved to the right in the figure. Move to the right. When the sub-wheel 50 further rotates clockwise from this state, as shown in FIG. 7C, the dense portion of the assist spring 90 is extended, and the assist spring 90 is swung to the right side of the drawing, and the output rod 31 is Move to the right side of

  Next, load characteristics of the clutch actuator according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 8 is a diagram schematically illustrating load characteristics of the clutch actuator according to the first embodiment of the present invention.

  By adjusting the lengths of the dense and rough portions of the unequal pitch assist spring (90 in FIG. 3B), the assist region can be expanded in accordance with the curve of the clutch load (assist in FIG. 8). (See the enlarged area). The assist load curve is set to be slightly lower than the clutch load curve in order to perform control by the electric motor (32 in FIG. 3). In FIG. 8, there is a difference between the clutch load curve at the time of new article and the clutch load curve at the time of wear, but the clutch load curve at the time of wear in FIG. 8 adjusts the change in the load characteristics of the clutch due to wear of the clutch facings 23a and 23b. (80 in FIG. 1) is not compensated, and when it is compensated by the adjusting mechanism (80 in FIG. 1), the clutch load curve at the time of the new article remains.

  According to the first embodiment, the following effects are obtained.

  First, the assist region can be expanded in accordance with the curve of the clutch load, the work amount of the electric motor 32 can be reduced, and the power consumption of the electric motor 32 can be reduced.

  Secondly, the electric motor 32 can be reduced in size by reducing the work amount of the electric motor 32.

  Third, by reducing the work amount of the electric motor 32, the stroke operating speed of the output rod 31 can be improved, and in particular, quickness (reactivity) when the clutch is released can be improved.

  Fourthly, when used in a large vehicle, the effects as described above become significant.

  Fifth, as in the prior art, the electric motor 32 and the output rod 31 can be disposed on the same side, and the longitudinal dimension of the actuator 30 as a whole can be greatly reduced, so that it is excellent in mountability and versatility. An actuator can be provided.

  The clutch actuator according to the first embodiment is not limited to the above configuration, and may be modified as follows.

  In the first embodiment, the support springs 41 and 42 are provided at one end and the other end of the assist spring 90, respectively, and are supported by the support pin 35e (or the regulation wall 38e) and the support portion 38d through the support bases 41 and 42, respectively. On the other hand, one end and the other end of the assist spring 90 are processed into a shape corresponding to the support bases 41 and 42, and the support pin 35e (or the regulation wall 38e) and the support portion 38d are thereby supported directly. It may be.

  In the first embodiment, the worm portion 34a is formed on the rotary shaft 34 of the electric motor 32, and the worm wheel 35 is connected to the gear to be rotated. On the other hand, for example, a gear may be provided on the rotating shaft 34, and a rotating body (worm wheel 35) may be gear-coupled to the rotating shaft 34 and driven to rotate.

  In the first embodiment, the housing 33 (the support portion 38d and the regulation wall 38e) is used as the non-moving portion. However, such a non-moving portion may be provided on the housing cover 37 side. Or you may provide using the suitable bracket etc. which fix the actuator 30 to a vehicle.

  The configuration adopted in the first embodiment is an example, and appropriate modifications may be made without departing from the present invention.

(Embodiment 2)
A clutch actuator according to Embodiment 2 of the present invention will be described with reference to the drawings. 9A is a front view schematically showing the clutch actuator according to Embodiment 2 of the present invention, and FIG. 9B is a sectional view of the assist spring in a free state.

  The clutch actuator according to the second embodiment is different from the first embodiment in the configuration of assist springs (coil springs 91 and 92). Other configurations and operations are the same as those in the first embodiment.

  In the clutch actuator according to the second embodiment, two coil springs 91 and 92 having an equal pitch and different lengths are used. The coil spring 91 is a coil spring having an equal pitch in a free state as shown in FIG. The coil spring 92 is a coil spring having an equal pitch in a free state as shown in FIG. The outer peripheral diameter of the coil spring 92 is smaller than the inner peripheral diameter of the coil spring 91. In the assembly of the clutch actuator 30, the coil spring 92 is disposed on the inner periphery of the coil spring 91 and between the support bases (corresponding to 41 and 42 in FIG. 4). In the assist spring in which the coil springs 91 and 92 are combined, the spring constant is small and only the coil spring 91 is deformed at the initial stage of bending, and the support base (corresponding to 41 and 42 in FIG. The constant increases and both the coil springs 91 and 92 are deformed. The coil spring 91 is supported between support bases (corresponding to 41 and 42 in FIG. 4) in a state where positioning pins (corresponding to 41b and 42b in FIG. 4) are inserted. The coil springs 91 and 92 are accommodated and supported using a space formed between the wheel portion 35 a of the worm wheel 35 and the sub wheel 50. When the worm wheel 35 rotates, the amount of deflection and the inclination of the coil springs 91 and 92 change in conjunction with the worm wheel 35.

  According to the second embodiment, the same effects as those of the first embodiment are obtained.

It is the schematic sectional drawing which showed typically the structure of the clutch apparatus with which the actuator for clutches concerning Embodiment 1 of this invention is applied. It is the front view which showed typically the structure of the state which notched some clutches in the clutch apparatus to which the actuator for clutches concerning Embodiment 1 of this invention is applied. It is the sectional view of the free state of the (A) front view and (B) assist spring which showed typically the composition of the actuator for clutches concerning Embodiment 1 of the present invention. It is sectional drawing between XX 'of FIG. 3 which showed typically the actuator for clutches concerning Embodiment 1 of this invention. FIG. 5 is a cross-sectional view taken along line YY ′ of FIG. 4 schematically illustrating the clutch actuator according to the first embodiment of the present invention. It is the figure which showed typically the relationship between the bending of the assist spring of the clutch actuator which concerns on Embodiment 1 of this invention, and load. It is a schematic diagram for demonstrating the movement of the assist spring of the actuator for clutches concerning Embodiment 1 of this invention. It is the figure which showed typically the load characteristic of the actuator for clutches concerning Embodiment 1 of this invention. It is the sectional view of the free state of (A) front view and (B) assist spring which showed typically the actuator for clutch concerning Embodiment 2 of the present invention. It is the (A) front view which showed typically the structure of the actuator for clutches concerning a prior art example, and (B) sectional drawing of the free state of an assist spring. It is the figure which showed typically the load characteristic of the actuator for clutches which concerns on a prior art example.

Explanation of symbols

10a Crankshaft 11a Transmission case 11b Support sleeve 20 Friction clutch 21 Flywheel 22 Clutch cover 22a Cylindrical part 22b Flange part 22c Support point forming part 23 Clutch disk 23a, 23b Clutch facing 24 Pressure plate 24a Strap 25 Diaphragm spring 25a Lever member 25b 25c fulcrum member 26 release bearing 26a force point portion 27 release fork 27a contact portion 27b substantially central portion 27c spring 28 pivot support member 30 actuator 31 output rod 32 electric motor (power source)
33 Housing 34 Rotating shaft 34a Worm part 35 Worm wheel (rotating body)
35a Wheel part 35b Connecting member (shaft part)
35c Gear part 35e Support pin (support part)
36 Assist spring 37 Housing cover 38 Housing part 38a Side wall 38b Bottom wall 38c Bearing part 38d Support part 38e Restriction wall 38f Guide groove 41, 42 Support base 41a, 42a Base part 41b, 42b Positioning pin 41c End face 50 Sub-wheel (Rotating body, Driven rotor)
50d Rod support pin 51 Housing part 51a Side wall 51b Bottom wall 51c Bearing part 50d Rod support pin 80 Adjustment mechanism 90 Assist spring 91, 92 Coil spring

Claims (4)

A power source, a rotating body that is rotationally driven by the power source, an output rod connected to the rotating body, one end supported by the housing, and the other end supported to assist the rotation of the rotating body. A clutch actuator that performs connection / disconnection and half-joining operation of the clutch by a stroke of the output rod,
When the assist spring bends with the rotation of the rotating body due to the stroke of the output rod, a portion with a small spring constant is deformed in the first half of the bend, and a portion with a large spring constant is deformed in the second half of the bend. A clutch actuator characterized by being configured as described above.   2. The clutch actuator according to claim 1, wherein in the free state, a pitch of a part of the coil is denser than a pitch of the other part in the assist spring.   The coil spring is configured such that a pitch dense portion having a small spring constant is deformed in the first half of bending, and a pitch coarse portion having a large spring constant is deformed in the second half of bending after the pitch dense portion is in close contact. The clutch actuator according to claim 2. The assist spring includes a first coil spring having an equal pitch, and a second coil spring that is shorter than the length of the first coil spring and smaller than the diameter of the first coil spring.
The first coil spring has one end supported by the housing and the other end supported by the rotating body so as to be relatively rotatable.
The clutch actuator according to claim 1, wherein the second coil spring is disposed on an inner peripheral side of the first coil spring.

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