Patent Publication Number: US-2023160469-A1

Title: Release device

Description:
TECHNICAL FIELD 
     The present invention relates to a release device in which a rotating section is rotated to release a parking position of a transmission. 
     BACKGROUND ART 
     In an electrical actuator described in Japanese Patent Application Laid-Open (JP-A) No. 2005-164037, rotation of a ring gear of a cogwheel set is anchored by a solenoid, and the cogwheel set couples an electric motor to a rotation stopper. By the electric motor being driven the rotation stopper is accordingly rotated via the cogwheel set, and a parking position of an automatic transmission is released. 
     In such an electrical actuator, the rotation anchoring of the ring gear in the cogwheel set is released by the solenoid, and coupling of the electric motor to the rotation stopper by the cogwheel set is released. The rotation stopper is thereby rotationally operated via a back-up shifter and attachment pin etc., and the parking position of the automatic transmission is released. 
     SUMMARY OF INVENTION 
     Technical Problem 
     In consideration of the above circumstances, an object of the present invention is to obtain a release device whose configuration can be simplified. 
     Solution to Problem 
     A release device of a first aspect of the present invention includes: a rotating section configured to be provided at a transmission of a vehicle and configured to release a parking position of the transmission by being rotated; a drive mechanism; and a coupling mechanism configured to couple the rotating section to the drive mechanism such that the rotating section is rotated by the drive mechanism being driven, and such that coupling between the rotating section and the drive mechanism is released by operational force applied to the rotating section so that the rotating section is rotated. 
     A release device of a second aspect of the present invention is the release device of the first aspect of the present invention wherein the coupling mechanism is configured to couple the rotating section to the drive mechanism using urging force, and configured such that coupling between the rotating section and the drive mechanism by the coupling mechanism is released against the urging force by the operational force applied to the rotating section. 
     A release device of a third aspect of the present invention is the release device of the first aspect or the second aspect of the present invention further including a limiting mechanism provided at the coupling mechanism and configured to limit rotation of the rotating section. 
     A release device of a fourth aspect of the present invention is the release device of the third aspect of the present invention further including a worm provided at the limiting mechanism, and a worm wheel provided at the limiting mechanism, the worm wheel being configured to mesh with the worm, and the worm limiting rotation of the worm wheel such that rotation of the rotating section is limited. 
     Advantageous Effects of Invention 
     In the release device of the first aspect of the present invention, the rotating section is provided at the vehicle transmission and the coupling mechanism couples the rotating section to the drive mechanism such that the rotating section is rotated by the drive mechanism being driven and the parking position of the transmission is released. 
     When the rotating section is operated, the coupling between the rotating section and the drive mechanism by the coupling mechanism is released by the operational force applied to the rotating section, and the rotating section is rotated. There is accordingly no need for a device to release the coupling between the rotating section and the drive mechanism by the coupling mechanism, enabling the configuration to be simplified. 
     In the release device of the second aspect of the present invention, the coupling mechanism couples the rotating section to the drive mechanism using the urging force. The coupling between the rotating section and the drive mechanism by the coupling mechanism is released against the urging force by operational force applied to the rotating section when the rotating section is operated. This enables the coupling mechanism to couple the rotating section to the drive mechanism and also enables the coupling between the rotating section and the drive mechanism by the coupling mechanism to be released, all with a simple configuration. 
     In the release device of the third aspect of the present invention, the limiting mechanism of the coupling mechanism limit rotation of the rotating section. This accordingly enables undesired rotation of the rotating section to be suppressed. 
     In the release device of the fourth aspect of the present invention, the worm and the worm wheel of the limiting mechanism are meshed together, and the worm limiting rotation of the worm wheel such that rotation of the rotating section is limited. This enables rotation of the rotating section to be limited with a simple configuration. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view of relevant portions of a transmission applied with an actuator according to an exemplary embodiment of the present invention, as viewed diagonally from a front-left. 
         FIG.  2    is a perspective view of an actuator according to an exemplary embodiment of the present invention, as viewed diagonally from a rear-left. 
         FIG.  3 A  is a perspective view illustrating relevant portions of an actuator according to an exemplary embodiment of the present invention while coupled. 
         FIG.  3 B  is a perspective view illustrating relevant portions of an actuator according to an exemplary embodiment of the present invention while coupling has been released. 
         FIG.  4    is an exploded perspective view illustrating relevant portions of an actuator according to an exemplary embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIG.  1    is a perspective view illustrating relevant portions of a transmission  12  (automatic transmission) applied with an actuator  10  serving as a release device according to an exemplary embodiment of the present invention, as viewed diagonally from the front-left. Note that in the drawings a front of the transmission  12  is indicated by arrow FR, a left of the transmission  12  is indicated by arrow LH, and upward in the transmission  12  is indicated by arrow UP. 
     As illustrated in  FIG.  1   , in the present exemplary embodiment a lock gear  14  is provided as a lock target in the transmission  12  of a vehicle (automobile). The lock gear  14  is able to rotate with a rotation center axis of the lock gear  14  parallel to a front-rear direction. A shift position of the transmission  12  is configured to be a parking position (parking lock of the vehicle is actuated) when rotation of the lock gear  14  has been locked, and the parking position of the transmission  12  is released (the vehicle parking lock is released) when locking of the rotation of the lock gear  14  has been released. 
     A substantially triangular plate shaped lock plate  16  serving as a locking member is provided at a left side of the lock gear  14 , and the lock plate  16  is configured so as to be rotatable about an upper end portion thereof. The rotation center axis of the lock plate  16  is parallel to the front-rear direction, and the lock plate  16  is urged toward the left side. A locking portion  16 A is integrally formed at a right end portion (right side and lower side end portion) of the lock plate  16 , and the locking portion  16 A projects out toward the right side. 
     A rear end portion of a substantially columnar switching shaft  18  serving as a switching member is disposed at the left side of a lower end portion (left side and lower side end portion) of the lock plate  16 , with the switching shaft  18  extending along a substantially front-rear direction, and capable of moving within a specific range in the front-rear direction. A substantially columner switching portion  18 A is coaxially provided at a rear end portion of the switching shaft  18 , with a large diameter portion  18 B coaxially provided at a front portion of the switching portion  18 A, and a small diameter portion  18 C coaxially provided at a rear portion of the switching portion  18 A. The diameter of the large diameter portion  18 B is larger than the diameter of the small diameter portion  18 C, with the diameter of a portion between the large diameter portion  18 B and the small diameter portion  18 C gradually larger on progression from the small diameter portion  18 C toward the large diameter portion  18 B. The large diameter portion  18 B engages with a lower end portion of the lock plate  16  when the switching shaft  18  has been moved toward the rear side, and the locking portion  16 A of the lock plate  16  engages (meshes) with the lock gear  14  by the lock plate  16  being swung toward the right side, thereby locking rotation of the lock gear  14 . The small diameter portion  18 C is engaged with the lower end portion of the lock plate  16  when the switching shaft  18  has been moved toward the front side, and the engagement of the locking portion  16 A with the lock gear  14  is released by the lock plate  16  being swung toward the left side, thereby releasing the lock on rotation of the lock gear  14 . 
     A substantially columner link shaft  20  serving as a link section is mechanically linked with a front end portion of the switching shaft  18 , with the link shaft  20  configured so as to be rotatable. A rotation center axis of the link shaft  20  is parallel to a left-right direction, with the switching shaft  18  being moved toward the rear side when the link shaft  20  has been rotated in a lock direction A (see  FIG.  1    and the like), and the switching shaft  18  being moved toward the front side when the link shaft  20  has been rotated in a release direction B (see  FIG.  1    and the like). 
     The actuator  10  (see  FIG.  2   ) is provided at the left side of the link shaft  20 . 
     A cuboidal box shaped case  22  serving as a housing body is provided at the actuator  10 , with the case  22  being configured by an assembly of a right case  22 A on the right side and a left case  22 B on the left side. 
     A substantially cylindrical shaft  24  (see  FIG.  3 A  and  FIG.  4   ) serving as a rotating section is provided inside the case  22 , with the shaft  24  configured so as to be rotatable. A rotation center axis of the shaft  24  is parallel to the left-right direction, with a left end and a right end of the shaft  24  respectively exposed at the left side and the right side of the case  22 . The link shaft  20  is coaxially fitted into the shaft  24  from the right side in such a manner that the shaft  24  is able to integrally rotate together with the link shaft  20 . 
     A motor  26  serving as a drive mechanism is fixed inside the case  22 , with an output shaft of the motor  26  extending forward. The motor  26  is electrically connected to a control device  28  of the vehicle, and the control device  28  is electrically connected to an emergency release switch  30  of the vehicle. The control device  28  controls the motor  26  based on operation of the emergency release switch  30  by an occupant (in particular a driver) of the vehicle, and the motor  26  is driven. 
     A coupling mechanism  32  is provided between the shaft  24  and the motor  26 . 
     A worm  34  serving as a first gear is provided at the coupling mechanism  32 . The worm  34  is fixed coaxially to the output shaft of the motor  26 , and the motor  26  is driven to rotate the worm  34 . 
     A helical gear  36  (worm wheel) serving as a second gear is meshed with the right side of the worm  34 , and the helical gear  36  is rotatably supported inside the case  22  with an axial direction parallel to an up-down direction. The worm  34  restricts rotation of the helical gear  36  (so-called self-locking), and the helical gear  36  is rotated by the worm  34  being rotated. 
     A worm shaft  38  (worm, see  FIG.  3 A ) serving as a third gear configuring a limiting mechanism is coaxially provided at an upper side of the helical gear  36 , with the worm shaft  38  rotatably supported inside the case  22 , and integrally rotated together with the helical gear  36 . 
     A substantially cylindrical coupling gear  40  (worm wheel, see  FIG.  3 A  and  FIG.  4   ) serving as a fourth gear (coupled member) configuring the limiting mechanism is meshed with a front side of the worm shaft  38 . The shaft  24  is coaxially inserted into and fitted together with the inside of the coupling gear  40 , such that the coupling gear  40  is rotatably supported by the shaft  24  and also restricted from moving toward the right side. The worm shaft  38  restricts rotation of the coupling gear  40  (so-called self-locking), and the coupling gear  40  is rotated by the worm shaft  38  being rotated. 
     A cylindrical insertion hole  40 A is coaxially formed at a portion at the radial direction inside and left side of a circumferential wall of the coupling gear  40 , with the insertion hole  40 A opening toward the left side. Plural (four in the present exemplary embodiment) coupling recesses  40 B serving as coupled portions are integrally formed at a right-side face (bottom face) of the insertion hole  40 A, with the plural coupling recesses  40 B being arranged at uniform intervals around the circumferential direction of the insertion hole  40 A, and with each respectively opening toward the left side. Each of the coupling recesses  40 B has a trapezoidal profile in cross-section taken along the circumferential direction of the insertion hole  40 A, with a dimension of each of the coupling recesses  40 B in the insertion hole  40 A circumferential direction getting larger on progression toward the left side. 
     A substantially cylindrical clutch  42  (see  FIG.  3 A  and  FIG.  4   ) serving as a coupling member is provided at the left side of the coupling gear  40 . The shaft  24  is coaxially inserted into and fitted together at the inside of the clutch  42 , and the clutch  42  is not able to rotate relative to the shaft  24  (i.e. is able to integrally rotate therewith) and is supported so as to be able to move along its axial direction (the left-right direction). 
     Plural (four in the present exemplary embodiment) coupling protrusions  42 A serving as coupling portions are integrally formed at a right-side end of the clutch  42 , with the plural coupling protrusions  42 A disposed at uniform intervals around the circumferential direction of the clutch  42 , and with each respectively protruding toward the right side. Each of the coupling protrusions  42 A has a trapezoidal profile in cross-section taken along the clutch  42  circumferential direction, with a dimension of the coupling protrusion  42 A in the clutch  42  circumferential direction increasing on progression toward the left side. The clutch  42  is coaxially fitted into the insertion hole  40 A of the coupling gear  40 , with the coupling protrusions  42 A fitted together with the coupling recesses  40 B of the insertion hole  40 A. 
     A coupling spring  44  (compression coil spring, see  FIG.  3 A ) serving as an urging member is provided at the left side of the clutch  42 , and the shaft  24  is coaxially inserted through the coupling spring  44 . A substantially circular ring-shaped anchor plate  46  serving as an anchoring member is provided at the left side of the coupling spring  44 , the shaft  24  is coaxially inserted through the anchor plate  46  such that the anchor plate  46  is supported by the shaft  24  in a manner so as not to be able to move in the axial direction thereof (left-right direction). The coupling spring  44  is compressed in the axial direction (left-right direction) between the clutch  42  and the anchor plate  46 , with the coupling spring  44  urging the clutch  42  toward the right side. The coupling spring  44  accordingly limits release of the fitting together of the coupling protrusions  42 A of the clutch  42  with the coupling recesses  40 B of the coupling gear  40  (the insertion hole  40 A), and the coupling spring  44  thereby limits relative rotation of the clutch  42  and the shaft  24  with respect to the coupling gear  40 . The coupling spring  44  is coupled to the coupling gear  40  and to the clutch  42  and the shaft  24  so as to be capable of rotating as a single body therewith, and when the coupling gear  40  is rotated the clutch  42  and the shaft  24  are rotated as a single body therewith. 
     A base end portion of an elongated plate-shaped operation lever  48  serving as an operation section is linked to the left side of the shaft  24  so as to be capable of rotating integrally therewith, with the operation lever  48  disposed at the left side of the case  22 . A manual lever  50  serving as a manual portion is mechanically connected to a leading end portion of the operation lever  48  through a cable  52 , with the manual lever  50  manually operable by the occupant. Operating the manual lever  50  accordingly enables the operation lever  48  to be swung in the release direction B through the cable  52 . 
     Next, description follows regarding operation and advantageous effects of the present exemplary embodiment. 
     In the actuator  10  of the transmission  12  configured as described above, the shaft  24  and the motor  26  are coupled by the coupling mechanism  32  (the worm  34 , the helical gear  36 , the worm shaft  38 , the coupling gear  40 , the clutch  42 , and the coupling spring  44 ). 
     Moreover, in the actuator  10 , the worm  34 , the helical gear  36 , and the worm shaft  38  are rotated by the motor  26  being forward driven under control of the control device  28 , and the coupling gear  40 , the clutch  42 , and the shaft  24  are thereby rotated in the lock direction A. The lock plate  16  is accordingly swung toward the right side by the link shaft  20  being rotated in the lock direction A and the switching shaft  18  being moved toward the rear side. Rotation of the lock gear  14  is accordingly locked by the locking portion  16 A of the lock plate  16 , and the shift position of the transmission  12  is at the parking position. 
     Furthermore, in the actuator  10 , the worm  34 , the helical gear  36 , and the worm shaft  38  are rotated by the motor  26  being reverse driven under control of the control device  28 , and the coupling gear  40 , the clutch  42 , and the shaft  24  are thereby rotated in the release direction B. The link shaft  20  is thereby rotated in the release direction B and the switching shaft  18  is moved toward the front side such that the lock plate  16  is swung toward the left side. The rotational locking of the lock gear  14  by the locking portion  16 A of the lock plate  16  is thereby released, and the parking position of the transmission  12  is released. 
     However, suppose the motor  26  were to be un-drivable due to a malfunction or the like of the transmission  12  or a vehicle battery (not illustrated in the drawings), then there would sometimes be a need to release the parking position of the transmission  12  (so as to enable movement of the vehicle). 
     Thus in such cases the manual lever  50  would be operated, and the operation lever  48  rotationally operated in the release direction B through the cable  52 , thereby releasing the fitting of the coupling protrusions  42 A of the clutch  42  into the coupling recesses  40 B of the coupling gear  40  (the insertion hole  40 A) against an urging force of the coupling spring  44 , such that the shaft  24  and the clutch  42  are rotationally operated as a single body with the operation lever  48 , in the release direction B with respect to the coupling gear  40 . The link shaft  20  is accordingly rotated in the release direction B, and the rotational locking of the lock gear  14  by the locking portion  16 A of the lock plate  16  is released by the switching shaft  18  moving toward the front side, and the parking position of the transmission  12  is thereby released. 
     In this manner, the coupling between the shaft  24  and the motor  26  by the coupling mechanism  32  (the coupling of the shaft  24  and the clutch  42  to the coupling gear  40 ) is released by rotational operation force to the shaft  24 , the shaft  24  is rotated in the release direction B, and the parking position of the transmission  12  is released. There is accordingly no need for a device to release the coupling between the shaft  24  and the motor  26  by the coupling mechanism  32  (i.e. the solenoid in above Patent Document 1), with this both simplifying the configuration of the actuator  10  and enabling the actuator  10  to be made more compact and at lower cost. 
     Moreover, the coupling mechanism  32  couples the shaft  24  to the motor  26  using the urging force of the coupling spring  44 . Furthermore, when the shaft  24  is rotationally operated via the manual lever  50 , the cable  52 , and the operation lever  48 , coupling between the shaft  24  and the motor  26  by the coupling mechanism  32  is released against the urging force of the coupling spring  44  by the rotational operation force to the shaft  24 . Thus the coupling mechanism  32  is able to couple the shaft  24  to the motor  26  using a simple configuration, and the coupling between the shaft  24  and the motor  26  is also able to be released by the coupling mechanism  32 . 
     Moreover, the worm shaft  38  restricts rotation of the coupling gear  40 . Furthermore, the coupling protrusions  42 A of the clutch  42  are fitted into the coupling recesses  40 B of the coupling gear  40  (the insertion hole  40 A) by the urging force of the coupling spring  44 , such that rotation of the clutch  42  and the shaft  24  with respect to the coupling gear  40  is limited. This enables rotation of the shaft  24  to be limited with a simple configuration, and enables undesirable rotation of the shaft  24  to be suppressed. 
     Furthermore, the coupling of the shaft  24  and the clutch  42  with the coupling gear  40  is released against the urging force of the coupling spring  44  both when a large load has been input to the shaft  24  from the lock gear  14  via the lock plate  16 , the switching shaft  18 , and the link shaft  20 , and when a large load has been input to the shaft  24  from the manual lever  50  via the cable  52  and the operation lever  48 . This accordingly enables a large load to be suppressed from being transmitted to the worm  34 , the helical gear  36 , the worm shaft  38 , and the coupling gear  40 , and enables the worm  34 , the helical gear  36 , the worm shaft  38 , and the coupling gear  40  to be suppressed from breaking. 
     Note that in the present exemplary embodiment the coupling recesses  40 B are provided at the coupling gear  40  and the coupling protrusions  42 A are provided at the clutch  42 . However, the coupling protrusions  42 A may be provided at the coupling gear  40  and the coupling recesses  40 B provided at the clutch  42 . 
     In the present exemplary embodiment the operation lever  48  is linked to the shaft  24 . However, the operation lever  48  may also be configured so as not to be linked to the shaft  24 . In such cases the shaft  24  may be configured so as to be rotatable using a tool. 
     Furthermore, in the present exemplary embodiment, the worm  34  (first gear) restricts rotation of the helical gear  36  (second gear), and the worm shaft  38  (third gear) restricts rotation of the coupling gear  40  (fourth gear). However, the worm shaft  38  may restrict rotation of the coupling gear  40  without the first gear restricting rotation of the second gear. Moreover, the worm  34  configuring the limiting mechanism may restrict rotation of the helical gear  36  configuring the limiting mechanism without the third gear restricting rotation of the fourth gear. 
     The entire content of the disclosure of Japanese Patent Application No. 2020-76925 filed on Apr. 23, 2020, is incorporated by reference in the present specification. 
     EXPLANATION OF THE REFERENCE NUMERALS 
     
         
           10  actuator (release device) 
           12  transmission 
           24  shaft (rotating section) 
           26  motor (drive mechanism) 
           32  coupling mechanism 
           38  worm shaft (limiting mechanism, worm) 
           40  coupling gear (limiting mechanism, worm wheel)