JP2006022880A - Coupling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately measure an engaging force with less energy loss when a transmission torque is adjusted by a clutch part. <P>SOLUTION: This coupling device comprises the clutch part 39 interposed between a rotating shaft 19 and a drive pinion shaft 21 and capable of adjusting the transmission torque according to the application and release of a pressing force thereto and therefrom, a cam mechanism 41 converting the rotating output of an electric motor 66 into a thrust force after increasing the rotating output to engage the clutch part 39, and a speed reduction gear mechanism 43 inputting the rotating output of the electric motor 66 to the cam mechanism 41 after reducing the speed of the electric motor. The device also comprises a countershaft 97 displacing by receiving the engagement reaction of the clutch part 39 through the speed reduction gear mechanism 43, a disc spring 103 imparting a reaction to the displacement of the countershaft 97, and a displacement sensor 107 detecting the displacement of the countershaft 97. The engagement force of the clutch part 39 is measured based on the displacement detected by the displacement sensor 107. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coupling device capable of detecting a fastening force when a friction clutch or the like is fastened by an electric motor or the like.

  In general, there is a coupling device in which a friction clutch is fastened using an electric motor or the like in a four-wheel drive vehicle or the like, and torque is transmitted to a rear wheel side (or front wheel side) that is a driven wheel according to a traveling state. When adjusting the control torque transmitted to the rear wheel side in accordance with the traveling state of the automobile with this coupling device, it is necessary to accurately detect the fastening force of the coupling device. The detection of the fastening force can be performed by measuring a displacement corresponding to the fastening force.

  However, the displacement according to the fastening force of the coupling device is such that the clearance of the friction multi-plate clutch is reduced, and the displacements x1 and x2 are extremely small compared to the case where the fastening forces F1 and F2 are large as shown in FIG. In addition, it has been substantially difficult to detect the fastening force due to changes in the compression characteristics of the clutch plate over time, changes due to temperature, flatness of the clutch plate, and the like.

  On the other hand, if a disc spring 205 is interposed between the friction multi-plate clutch 201 and the coupling housing 203 as shown in FIG. 9, the amount of displacement for fastening the friction multi-plate clutch 201 is increased, and according to the displacement amount. It is possible to detect the fastening force relatively accurately.

  However, since the fastening torque itself acts on the disc spring 205, it is necessary to use a disc spring 205 having a large spring constant. For this reason, as shown in FIG. 10, the spring reaction forces F3 and F4 of the disc spring 205 with respect to the displacements x1 and x2 become extremely large, and the reaction force is transmitted as a rotational reaction force to the electric motor. The operation energy is required, and further, the operation response is deteriorated and the capacity of the electric motor is increased.

Japanese Patent Laid-Open No. 3-66927

  The problem to be solved is that if a spring is interposed in order to accurately detect the fastening force of the coupling device and the amount of displacement corresponding to the fastening force is increased, energy loss increases and response is deteriorated. This is a point that increases the size of the motor.

  The present invention provides a rotational output of an actuator to suppress an increase in energy loss while increasing the amount of displacement according to the fastening force by interposing an urging member in order to accurately detect the fastening force of the coupling device. And a decelerating part that decelerates and inputs to the conversion means, and a movable part that displaces by receiving the fastening reaction force of the clutch part via the decelerating part is provided, and an urging force that applies a reaction force to the displacement of the movable part The main feature is that a member is provided, a displacement sensor for detecting the displacement of the movable portion is provided, and the fastening force of the clutch portion is measured based on the displacement detected by the displacement sensor.

  The coupling device of the present invention includes a speed reduction unit that decelerates and outputs the rotational output of the actuator to the conversion means, and provides a movable part that is displaced by receiving the fastening reaction force of the clutch part via the speed reduction unit, An urging member that provides a reaction force to the displacement of the movable portion is provided, a displacement sensor that detects the displacement of the movable portion is provided, and the clutch portion is configured to measure the fastening force of the clutch portion based on the displacement detected by the displacement sensor. When the movable part receives the fastening reaction force via the speed reduction part, the displacement amount of the movable part can be amplified. In addition, the urging member does not act on the fastening force itself of the clutch portion, but acts on the urging member with a small force via the speed reduction portion, and a member having a small spring constant can be used. Accordingly, the displacement of the movable portion can be increased with a small force, and a large displacement amount can be detected with a small force regardless of the fastening force of the clutch portion. For this reason, while obtaining an accurate control torque of the coupling device, it is possible to reduce the required energy for operation, improve the response, and reduce the size and weight by reducing the capacity of the electric motor.

  The displacement of the movable part is in the direction of the rotational axis or the rotational radial direction, and when the displacement sensor detects the displacement of the end surface in the rotational axis direction or the side surface in the rotational axis direction of the movable part, the displacement is accurately detected. be able to.

  When the movable part is a component part of the speed reducing part, the structure can be simplified without requiring any special part as the movable part.

  The reduction portion is a gear reduction mechanism including a reduction gear set of a helical gear, and one of the helical gears is provided on an intermediate shaft that is supported so as to be axially displaceable, and the urging member is the fastening reaction of the intermediate shaft. When energizing against axial displacement due to force, the displacement of the intermediate shaft can be increased with a small force, and a large amount of displacement can be detected with a small force regardless of the fastening force of the clutch part, Accurate fastening force detection can be performed while suppressing energy loss.

  When the movable part is the actuator, the structure can be simplified without requiring any special parts as the movable part.

  The speed reduction unit is a gear speed reduction mechanism including a reduction gear set of a helical gear, the actuator is supported so that the actuator housing cannot rotate and is axially displaceable, and the biasing member fastens the actuator housing When urging against the axial displacement due to the reaction force, the displacement of the actuator can be increased with a small force, and a large amount of displacement can be detected with a small force regardless of the fastening force of the clutch part, Accurate fastening force detection can be performed while suppressing energy loss.

  The speed reduction part is a gear speed reduction mechanism formed of a worm and a worm wheel, the actuator is supported so that the actuator housing cannot rotate and can be displaced in the axial direction, and the biasing member is the fastening of the actuator housing When urging against the axial displacement due to the reaction force, the displacement of the actuator can be increased with a small force, and a large amount of displacement can be detected with a small force regardless of the fastening force of the clutch part, Accurate fastening force detection can be performed while suppressing energy loss.

  The conversion means is a cam mechanism in which the cam plate faces in the direction of the rotation axis. When the cam plate is relatively rotated at a low speed by an input from the speed reduction unit, the rotation output of the actuator is increased and converted into a thrust force. And it can transmit to a clutch part reliably. Further, the engagement reaction force of the clutch portion can be converted into a rotational force and transmitted to the speed reduction portion side, and a large displacement can be detected with a small force regardless of the engagement force of the clutch portion.

  When the actuator is an electric motor, the clutch portion can be securely fastened by the rotation output of the electric motor.

  The purpose of accurately measuring the fastening force with less energy loss when adjusting the transmission torque by the clutch part is realized by receiving the fastening reaction force of the clutch part by the urging member through the reduction part.

  FIG. 1 is a cross-sectional view showing the arrangement of a coupling device according to Embodiment 1 of the present invention, and FIG. The coupling device 1 is disposed, for example, between a rear differential device and a propeller shaft of a laterally mounted front engine front drive base (FF base) part-time four-wheel drive vehicle (also referred to as an on-demand four-wheel drive vehicle). Has been. The rear differential device is a driven-side differential device with respect to a main drive-side front differential device to which a driving force is always transmitted.

  The coupling device 1 is disposed in the carrier cover 3. The carrier cover 3 constitutes a carrier together with a differential carrier 5 that is a carrier body, and is detachably attached to the differential carrier 5 with bolts or the like.

  The carrier cover 3 includes a large diameter portion 7 and a small diameter portion 9. An actuator support portion 11 is provided at the step between the large diameter portion 7 and the small diameter portion 9. The actuator support portion 11 includes a joint portion 13 on the large-diameter portion 7 side and a lid portion 15 provided detachably on the joint portion 13. The lid portion 15 is fastened and fixed to the joint portion 13 by bolts and nuts at a flange portion (not shown) on the outer peripheral side.

  The coupling device 1 includes a rotating shaft 19 that is a rotating member on one end side and a drive pinion shaft 21 that is a rotating member on the other end side.

  The rotating shaft 19 protrudes from the shaft support portion 17 at the tip of the small diameter portion 9 of the carrier cover 3 and is coupled to the propeller shaft via a universal joint. The rotating shaft 19 is rotatably supported by the shaft support portion 17 of the carrier cover 3 by a ball bearing 23. A coupling flange 25 is spline-engaged with the outer end of the rotating shaft 11. The coupling flange 25 is fastened to the rotary shaft 19 by a nut 27 and is prevented from coming off. A seal 27 is provided between the coupling flange 25 and the shaft support portion 17 of the carrier cover 3. A coupling flange 25 is coupled to the universal joint.

The drive pinion shaft 21 is rotatably supported by a bearing housing 31 of the differential carrier 5 by a unit bearing 29 having a pair of tapered rollers. The unit bearing 29 is fastened by a nut 33 that is screwed onto the drive pinion shaft 21. By this fastening, a preload (preload) is applied to the unit bearing 29. In the differential carrier 5, the drive pinion shaft 21 is interlocked and coupled with the drive pinion gear 35 meshing with the ring gear 37 of the rear differential device.
The coupling device 1 includes a clutch mechanism 39, a cam mechanism 41 as a conversion unit, and a gear reduction mechanism 43 as a reduction unit.

  The clutch portion 39 is interposed between the rotary shaft 19 and the drive pinion shaft 21 and can adjust the transmission torque according to the application and release of the pressing force. The clutch portion 39 includes a clutch outer cylinder 45 and a clutch hub 47.

  The clutch outer cylinder 45 is integrally provided with a circumferential vertical wall portion 49 on the inner peripheral side thereof. An inner peripheral boss 51 is integrally provided on the inner peripheral edge of the vertical wall portion 49. The inner peripheral boss 51 is spline-engaged with the end of the drive pinion shaft 21. The clutch outer cylinder 45 is engaged with the drive pinion shaft 21 in the rotational direction by this spline engagement. The inner peripheral boss 51 is pressed against the nut 33 in the axial direction and is positioned by a snap ring 53 provided at the end of the drive pinion shaft 21.

  The clutch hub 47 is integrally provided at one end of the rotary shaft 19. That is, the clutch hub 47 is integrally coupled to the rotary shaft 19 through the vertical wall portion 55 and the hollow portion 56. The vertical wall portion 55 is provided to face the vertical wall portion 49 of the clutch outer cylinder 45 in the axial direction. In the hollow portion 56, the inner peripheral side of the vertical wall portion 55 is integrally coupled to one end portion, and the other end portion of the hollow portion 56 is integrally provided coaxially with the rotary shaft 19. An inner peripheral boss portion 51 of the clutch outer cylinder 45 is loosely fitted in the hollow portion 56 in the radial direction. In addition, a needle bearing can be provided between the inner peripheral boss portion 51 and the hollow portion 56 or between the drive pinion shaft 21 and the hollow portion 56 and can be supported with each other. By this support, the support rigidity between the rotary shaft 19 and the drive pinion shaft 21 can be improved, and rattling, vibration, and the like can be suppressed.

  A friction multi-plate clutch 57 is provided between the clutch outer cylinder 45 and the clutch hub 47. The friction multi-plate clutch 57 has an outer plate that is spline-engaged with the clutch outer cylinder 45 and an inner plate that is spline-engaged with the clutch hub 47. Therefore, torque transmission between the clutch outer cylinder 45 and the clutch hub 47 can be performed by the friction engagement of the friction multi-plate clutch 57.

  A pressure receiving portion 59 formed on the outer peripheral portion of the vertical wall portion 49 is disposed on one end side between the clutch outer cylinder 45 and the clutch hub 47, and a pressing plate 61 is disposed opposite to the other end side portion. .

  Referring also to the enlarged cross-sectional view of the main part of FIG. 2, the pressing plate 63 of the pressing plate 61 is fitted between the clutch outer cylinder 45 and the clutch hub 47. A cam connecting portion 65 is integrally provided on the inner peripheral portion of the pressing plate 61. A linkage support portion 67 is provided around the inner peripheral edge of the cam linkage portion 65 in a circular shape.

  The cam mechanism 41 constitutes conversion means for increasing the rotational output of the electric motor 66 as an actuator and converting it into a thrust force in order to fasten the clutch portion 39. The cam mechanism 41 includes a pair of cam plates 69 and 71 and a cam ball 77 interposed between the cam surfaces 73 and 75 of the cam plates 69 and 71. One cam plate 69 is provided integrally with the small-diameter portion 9 of the carrier cover 3, and the other cam plate 71 is disposed opposite to the cam plate 69 in the rotation axis direction.

  A cylindrical portion 79 is provided on the inner peripheral side of the cam plate 71, and the cylindrical portion 79 is rotatably supported by an end inner peripheral surface 83 having a circular cross section of the small diameter portion 9 via a radial needle bearing 81. Yes. Further, the inner periphery of the cam plate 71 is fitted to the linkage support portion 67 of the pressing plate 61 and supported so as to be relatively rotatable. Therefore, the support rigidity between the cam mechanism 41 and the pressing plate 61 can be improved. A thrust needle bearing 85 is interposed between the cam connecting portions 65 of the cam plate 71 and the pressing plate 61.

  The electric motor 66 includes a drive shaft 68 and is detachably fixed to the lid portion 15 of the actuator support portion 11.

  The gear reduction mechanism 43 decelerates the rotational output of the electric motor 66 and inputs it to the cam mechanism 41. The gear reduction mechanism 43 includes a reduction gear set including first and second helical gears 87 and 89, and a reduction gear set including third and fourth helical gears 91 and 93. The gear reduction mechanism 43 is configured to decelerate in two stages by a set of first and second helical gears 87 and 89 and a set of third and fourth helical gears 91 and 93. Note that either the set of the first and second helical gears 87 and 89 and the set of the third and fourth helical gears 91 and 93 can be configured by a spur gear or the like.

  The first helical gear 87 is formed integrally with the drive shaft 68 of the electric motor 66. The second helical gear 89 meshes with the first helical gear 87 and is provided integrally with the intermediate shaft 97. The third helical gear 91 is provided integrally with the intermediate shaft 97 together with the second helical gear 89. The fourth helical gear 93 meshes with the third helical gear 91 and is provided integrally with the outer peripheral portion of the cam plate 71.

  The intermediate shaft 97 is movably supported by the movable support holes 99 and 101. The movable support hole 99 is provided in the side wall 102 of the large diameter portion 7 of the carrier cover 3. The movable support hole 101 is provided in the lid portion 15 of the actuator support portion 11 of the carrier cover 3. An interval allowing the axial displacement of the intermediate shaft 97 is provided between the movable support hole 101 and the intermediate shaft 97 in the axial direction. A disc spring 103 and a thrust needle bearing 105 are interposed between the second helical gear 89 and the lid portion 15. The disc spring 103 constitutes an urging member that gives a reaction force to the displacement of the intermediate shaft 97. The intermediate shaft 97 integrally provided with the second and third helical gears 89 and 91 is a component part of the gear reduction mechanism 43 that is a reduction portion, and the engagement reaction force of the clutch portion 39 is transmitted to the gear reduction mechanism 43. The movable part which is displaced by receiving via is comprised.

  The displacement of the intermediate shaft 97 that is the movable portion is detected by a displacement sensor 107. The displacement sensor 107 is supported on the lid portion 15 side, and detects the displacement of its end face as detecting the displacement of the intermediate shaft 97 in the rotation axis direction.

  As the displacement sensor 107, either a non-contact type or a contact type can be used. As the non-contact type, a capacitance sensor, an optical sensor, a sound wave sensor, a magnetic field sensor, or the like can be used. As the contact type, a gauge or the like can be used.

  The displacement detected by the displacement sensor 107 is input to a controller constituted by, for example, a microcomputer, and the fastening force of the clutch portion 39 is sequentially measured by the calculation of the controller.

  Next, the operation will be described.

  When the electric motor 66 is not energized and the clutch portion 39 is not fastened during normal travel, the rotation between the rotary shaft 19 and the drive pinion shaft 21 is free. Therefore, the automobile can travel in the two-wheel drive state with the front wheels as described above.

  When the electric motor 66 is energized and controlled due to the necessity of traveling on a rough road, the rotation output of the electric motor 66 is input to the first helical gear 87 via the drive shaft 68. The rotation of the first helical gear 87 is decelerated and transmitted to the cam plate 71 through the meshing of the first and second helical gears 87 and 89 and the meshing of the intermediate shaft 97 and the third and fourth helical gears 91 and 93. The

  Due to the reduced rotational transmission to the cam plate 71, the cam plate 71 rotates relative to the cam plate 69 at a low speed. The cam ball 77 rides on the cam surfaces 73 and 75 by the relative rotation of the cam plate 71 with respect to the cam plate 69, and the cam mechanism 41 works. Due to the operation of the cam mechanism 41, the rotational input decelerated from the electric motor 66 is converted into a thrust force. This thrust force is transmitted from the cam plate 71 to the cam connecting portion 65 of the pressing plate 61 through the thrust needle bearing 85 as a reaction force against the small diameter portion 9 side of the carrier cover 3, and the cam connecting portion 65 receives a moving force. . By this moving force, the pressing portion 63 of the pressing plate 61 presses the friction multi-plate clutch 57. By this pressing, the friction multi-plate clutch 57 is fastened between the pressing plate 61 and the pressure receiving portion 59.

  The torque transmitted from the rotary shaft 19 to the hollow portion 56, the vertical wall portion 55, and the clutch hub 47 by the engagement of the friction multi-plate clutch 57 is transmitted to the clutch outer cylinder 45 via the friction multi-plate clutch 57. The Torque is transmitted from the clutch outer cylinder 45 to the drive pinion shaft 21 via the vertical wall portion 49 and the inner peripheral boss portion 51.

  Therefore, the automobile can travel in a four-wheel drive state with front and rear wheels, and can improve the traveling performance on rough roads where the front wheels and the like slip.

  The torque transmitted to the rear wheel can be adjusted according to the application and release of the pressing force by the pressing plate 61 of the friction multi-plate clutch 57. This adjustment can be accurately performed by detecting the fastening force of the friction multi-plate clutch 57.

  That is, when the friction multi-plate clutch 57 is engaged, the engagement reaction force of the friction multi-plate clutch 57 is transmitted to the pressing plate 61, the thrust needle bearing 85, and the cam plate 71 through the reverse transmission route, and the cam ball 77 and the cam surfaces 73 and 75 are converted into rotational reaction forces and act on the meshing portions of the second and first helical gears 89 and 87 via the fourth and third helical gears 93 and 91 and the intermediate shaft 97. To do. Since the fourth and third helical gears 93 and 91 and the second and first helical gears 89 and 87 are helical helical gears, the intermediate shaft 97 is moved in the axial direction by the action of the rotational reaction force on the meshing portion. The force is received and displaced against the reaction force of the disc spring 103. This displacement is detected by the displacement sensor 107, and the fastening force of the clutch portion 39 is sequentially measured by the controller as described above. By measuring the fastening force, the controller can accurately control the energization of the electric motor 66 and adjust the transmission torque accurately.

  In addition, since the engagement reaction force of the frictional multi-plate clutch 57 is input to the meshing portions of the fourth and third helical gears 93 and 91 and the second and first helical gears 89 and 87 of the gear reduction mechanism 43, the engagement is performed. The displacement amount of the intermediate shaft 97 can be amplified with respect to the reaction force. Further, not the fastening force itself of the friction multi-plate clutch 57 acts on the disc spring 103, but a small force acts on the disc spring 103 via the reduction gear mechanism 43, which is a reduction portion. Can be used. Accordingly, the relationship between the displacements x1 and x2 of the intermediate shaft 97 and the displacement force of the intermediate shaft 97 can be made as shown in FIG. 3, and a large amount of displacement can be obtained with a small force regardless of the fastening force of the friction multi-plate clutch 57. Therefore, it is possible to detect the fastening force accurately while suppressing energy loss.

  Since the intermediate shaft 97 of the gear reduction mechanism 43 constitutes a movable part, the structure can be simplified without requiring any special parts as the movable part.

  The displacement sensor 107 can also be configured to detect a radial displacement of the intermediate shaft 97, that is, a rotational displacement of the side surface of the intermediate shaft 97 and a rotational displacement of the second and third helical gears 89 and 91. The movable part can also be constituted by the second and third helical gears 89, 91 and the like. Also in this case, the displacement can be detected by either the displacement in the rotation axis direction or the rotation displacement.

  The intermediate shaft 97 is supported so as not to be displaceable in the axial direction, and the intermediate shaft 97 supports one of the second and third helical gears 89 and 91 so as to be relatively displaceable in the axial direction to form a movable portion. The displacement in the rotational axis direction or the rotational displacement of any of the third helical gears 89 and 91 may be detected.

  FIG. 4 is a sectional view of the torque transmission device showing the arrangement of the coupling device according to the second embodiment of the present invention, and FIG. 5 is an enlarged sectional view of the main part of the device. Note that components corresponding to those in the first embodiment will be described with the same reference numerals or A added to the same reference numerals.

  In the coupling device 1A of the present embodiment, an electric motor 66A itself that is an actuator is used as a movable portion.

  In the carrier cover 3A, a constricted portion 111 is provided in the actuator supporting portion 11A, and an inner spline 113 is provided in the constricted portion 111. A support cylinder 115 is provided outside the constricted part 111.

  The electric motor 66A is provided with a flange portion 119 and a head portion 121 in a motor housing 117 as an actuator housing. A spline 123 is provided on the head 121. The spline 123 is spline-engaged with the inner spline 113 on the constricted portion 111 side of the actuator support portion 11A. A snap ring 125 is attached to the support tube portion 115 on the inner periphery on the front end side. Belleville springs 103Aa and 103Ab are interposed between the snap ring 125 and the flange portion 119 of the electric motor 66A, and between the back wall of the support cylinder portion 115 and the flange portion 119.

  The first and third helical gears 87A and 91A of the gear reduction mechanism 43A are provided on the drive shaft 68A of the electric motor 66A. The second helical gear 89A is provided on the cam plate 69A. The helical gear ratio between the first and second helical gears 87A and 89A is slightly larger than the helical gear ratio between the third and fourth helical gears 91A and 93A.

  The cam plate 69A is formed separately from the small-diameter portion 9A of the carrier cover 3A in this embodiment, and a cylindrical portion 125 is provided on the inner periphery. The cylindrical portion 125 is supported in the axial direction and the rotational direction via a metal bearing 129 having an L-shaped cross section by a cam support portion 127 provided at the end of the small diameter portion 9A, and the cam plate 69A is supported by the small diameter portion 9A. On the other hand, it is relatively rotatable.

  When the first and third helical gears 87A and 91A are driven via the drive shaft 68A by the energization control of the electric motor 66A, the helical gear ratio between the first and second helical gears 87A and 89A and the third and third helical gears 87A and 89A Due to the difference in the helical gear ratio between the fourth helical gears 91A and 93A, the cam plates 69A and 71A relatively rotate at a low speed. By this relative rotation, the cam ball 77 rides on the cam surfaces 73 and 75, and the cam mechanism 41A works. In this manner, the friction multi-plate clutch 57 can be fastened as in the above embodiment.

  At the time of this engagement, the engagement reaction force of the friction multi-plate clutch 57 is generated between the first and second helical gears 87A and 89A and between the third and fourth helical gears 91A and 93A of the gear reduction mechanism 43A via the cam mechanism 41A. In the same manner as in the case of the intermediate shaft 97, the drive shaft 68A can be amplified and displaced in the axial direction. Due to this axial displacement of the drive shaft 68A, the electric motor 66A receives a displacement force and is displaced in the axial direction against the reaction force of the disc spring 103Aa while being guided by the spline engagement of the head 121.

  Accordingly, in this embodiment, the relationship between the displacements x1 and x2 of the electric motor 66A and the displacement forces F5 and F6 of the electric motor 66A is as shown in FIG. 3, and with a small force regardless of the fastening force of the friction multi-plate clutch 57. A large amount of displacement can be detected, and accurate fastening force detection can be performed while suppressing energy loss.

  Since the electric motor 66A, which is the actuator, constitutes the movable part, the structure can be simplified without requiring any special parts as the movable part.

  Note that the displacement measurement location by the displacement sensor may be either the end face or the side face of the electric motor 66A.

  6 is a cross-sectional view of the torque transmission device showing the arrangement of the coupling device according to the third embodiment of the present invention, and FIG. 7 is a cross-sectional view taken along the arrow SA-SA in FIG. Note that components corresponding to those of the first embodiment will be described with the same reference numerals or B added to the same reference numerals.

  As shown in FIGS. 6 and 7, the coupling device 1 </ b> B of the present embodiment is disposed in a case 131 configured as a carrier cover or the like. The case 131 is provided with an actuator support portion 11B. A step portion 111B is provided on the actuator support portion 11B, and an inner spline 113B is provided on the step portion 111B. A support cylinder portion 115B is provided on the outer side with respect to the step portion 111B.

  The coupling device 1B includes rotating shafts 133 and 135 that are a pair of rotating members.

The rotating shafts 133 and 135 protrude from both sides of the case 131, and the rotating shaft 133 is coupled to a propeller shaft through, for example, a universal joint. The rotating shaft 135 is coupled to, for example, a drive pinion shaft.
The coupling device 1B includes a clutch mechanism 39B, a cam mechanism 41B as a converting means, and a gear speed reducing mechanism 43B as a speed reducing section.

  The clutch portion 39B is interposed between the rotary shafts 133 and 135 and can adjust the transmission torque according to the application and release of the pressing force. The clutch portion 39B includes a clutch outer cylinder 45B and a clutch hub 47B.

  The clutch outer cylinder 45 </ b> B has a vertical wall portion 49 </ b> B integrally coupled to the rotary shaft 135. A needle bearing 137 is interposed between the clutch outer cylinder 45 </ b> B and the case 131. The clutch hub 47B is integrally provided at one end of the rotating shaft 133.

  In the cam mechanism 41B, one cam plate 69B is formed integrally with a part of the case 131, and the other cam plate 71B is formed integrally with a part of a worm wheel 139 of the gear reduction mechanism 43B. .

  The gear reduction mechanism 43B includes the worm wheel 139 and the worm 141. The worm wheel 139 is supported on the rotary shaft 133 via a metal bearing 143 so as to be relatively rotatable. The worm 141 is provided integrally with the drive shaft 68B of the electric motor 66B.

  In the electric motor 66B, a cover 145 is detachably attached to the motor housing 117B. A ball bearing 147 is interposed between the cover 145 and the drive shaft 68B. The cover 145 is provided with a flange portion 119B and a head portion 121B. A spline 123B is provided on the head 121B. The spline 123B is spline-engaged with the inner spline 113B on the stepped portion 111B side of the actuator support portion 11B.

  A snap ring 125B is attached to the inner periphery of the distal end side of the support cylinder portion 115B. A disc spring 103B is interposed between the snap ring 125B and the flange portion 119B.

  When the electric motor 66B is energized and controlled, the rotation of the electric motor 66B is greatly decelerated and transmitted to the worm wheel 139 due to the deceleration between the worm 141 and the worm wheel 139. The cam plates 69B and 71B rotate relative to each other by the decelerated rotation of the worm wheel 139. By this relative rotation, the cam mechanism 41B works, and the friction multi-plate clutch 57B is fastened through the worm wheel 139, the thrust needle bearing 85B, and the pressing plate 61B in this order.

  Therefore, as described above, the automobile can travel in a four-wheel drive state using front and rear wheels, for example, and can improve traveling performance on a rough road where the front wheels and the like slip.

  The transmission torque to the rear wheel can be adjusted according to the application and release of the pressing force by the pressing plate 61B of the friction multi-plate clutch 57B. This adjustment can be accurately performed by detecting the fastening force of the friction multi-plate clutch 57B as described above.

  In this embodiment, when the friction multi-plate clutch 57B is engaged, the engagement reaction force of the friction multi-plate clutch 57B is transmitted to the pressing plate 61B, the thrust needle bearing 85B, and the worm wheel 139 through the reverse transmission route. Then, it is converted into a rotational reaction force between the cam ball 77 and the cam surfaces 73 and 75. This rotational reaction force is transmitted from the worm wheel 139 to the worm 141. Due to this rotation transmission, the worm 141 does not rotate but receives a displacement force in the axial direction by meshing with the worm wheel 139.

  The drive shaft 68B can be amplified and displaced in the axial direction by the displacement force. Due to this axial movement of the drive shaft 68B, the electric motor 66B receives a displacement force, and the electric motor 66B is displaced in the axial direction against the reaction force of the disc spring 103B while being guided by the spline engagement of the head 121B.

  Therefore, also in this embodiment, the relationship between the displacements x1 and x2 of the electric motor 66B and the displacement forces F5 and F6 of the electric motor 66B is as shown in FIG. 3, and with a small force regardless of the fastening force of the friction multi-plate clutch 57B. A large amount of displacement can be detected, and accurate fastening force detection can be performed while suppressing energy loss.

  In the third embodiment, the displacement measurement location by the displacement sensor may be either the end surface or the side surface of the electric motor 66B.

  In each of the above-described embodiments, another member interlocked with the intermediate shaft 97 and the electric motors 66A and 66B may be provided, and a configuration in which the displacement of the member in the rotation axis direction and the rotation displacement are detected may be employed. When other members are provided, the measurement reference plane can be enlarged and the amount of displacement can be increased, and the measurement accuracy can be improved.

It is sectional drawing which shows arrangement | positioning of a coupling apparatus (Example 1). It is a principal part expanded sectional view of a coupling apparatus (Example 1). It is a graph which shows the relationship between force and displacement (Example 1). It is sectional drawing which shows arrangement | positioning of a coupling apparatus (Example 2). (Example 2) which is a principal part expanded sectional view of a coupling apparatus. It is sectional drawing which shows arrangement | positioning of a coupling apparatus (Example 3). (Example 3) which is SA-SA arrow sectional drawing of FIG. It is a graph which shows the relationship between force and displacement (conventional example). It is sectional drawing which shows arrangement | positioning of a coupling apparatus (conventional example). It is a graph which shows the relationship between force and displacement (conventional example).

Explanation of symbols

1, 1A, 1B Coupling device 19, 133, 135 Rotating shaft (Rotating member)
21 Drive pinion shaft (rotating member)
39, 39B Clutch part 41, 41A, 41B Cam mechanism (conversion means)
43, 43A, 43B Gear reduction mechanism (reduction part)
66 Electric motor (actuator)
66A, 66B Electric motor (actuator, moving part)
69, 69A, 69B, 71, 71B Cam plate 97 Intermediate shaft (movable part)
103, 103Aa, 103Ab, 103B Belleville spring (biasing member)
107 Displacement sensor

Claims (9)

A clutch portion interposed between the rotating members and capable of adjusting the transmission torque according to the application and release of the pressing force;
Conversion means for increasing the rotational output of the actuator and converting it into a thrust force in order to fasten the clutch part;
A decelerating unit that decelerates the rotational output of the actuator and inputs it to the conversion means;
Providing a movable part that is displaced by receiving the fastening reaction force of the clutch part through the speed reduction part;
An urging member that provides a reaction force to the displacement of the movable part is provided,
A displacement sensor for detecting the displacement of the movable part;
A coupling device that measures a fastening force of the clutch portion based on a displacement detected by the displacement sensor. The coupling device according to claim 1,
The displacement of the movable part is the rotation axis direction or the rotation radius direction,
The said displacement sensor detects the displacement of the rotating shaft direction end surface or rotating shaft direction side surface of the said movable part, The coupling apparatus characterized by the above-mentioned. The coupling device according to claim 1 or 2,
The movable device is a component of the speed reduction unit. The coupling device according to claim 3,
The reduction part is a reduction gear mechanism including a reduction gear set of a helical gear,
One of the helical gears is provided on an intermediate shaft supported so as to be axially displaceable,
The coupling device according to claim 1, wherein the biasing member biases the intermediate shaft against axial displacement caused by the fastening reaction force. The coupling device according to claim 1 or 2,
The coupling device, wherein the movable part is the actuator. The coupling device according to claim 5,
The reduction part is a gear reduction mechanism provided with a reduction gear set of a helical gear,
The actuator is supported such that the actuator housing is non-rotatable and axially displaceable,
The coupling device according to claim 1, wherein the biasing member biases the actuator housing against axial displacement caused by the fastening reaction force. The coupling device according to claim 5,
The speed reduction part is a gear speed reduction mechanism formed of a worm and a worm wheel,
The actuator is supported such that the actuator housing is non-rotatable and axially displaceable,
The coupling device according to claim 1, wherein the biasing member biases against an axial displacement caused by the fastening reaction force of the actuator housing. The coupling device according to any one of claims 1 to 7,
The conversion means is a cam mechanism that is opposed to a cam plate in a rotation axis direction,
A coupling device characterized in that the cam plate is relatively rotated at a low speed by an input from the speed reduction unit. A coupling device according to any one of claims 1 to 8,
The coupling device, wherein the actuator is an electric motor.

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