JP2015042893A - Clutch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new clutch mechanism capable of improving a steering feeling of a steering gear.SOLUTION: A clutch device 58 switches transmission and cutoff of torque between two rotary shafts. The device includes: a steering-side housing 36 on which a plurality of grooves is circumferentially formed on its inner or outer periphery with intervals with each other; a tire-side housing 38 arranged coaxial with the steering-side housing so that at least part thereof is overlapped; and a plurality of lock bars 60 provided on the tire-side housing to enable movement in the radial direction of the tire-side housing and arranged in the circumferential direction of the tire-side housing 38 with intervals with each other. The plurality of lock bars 60 includes a lock bar 601 entering a lock groove 621 and transmitting torque in one rotational direction, a lock bar 603 entering a lock groove 623 and transmitting torque in the other rotational direction.

Description

  The present invention relates to a clutch device, and more particularly to a clutch device used for a vehicle steering device.

  In recent years, various systems relating to steering of automobiles, so-called steer-by-wire systems, have been developed for practical use. Conventional vehicles generally have a steering wheel and a steered wheel mechanically coupled through a mechanism such as a rack and pinion. However, in the steer-by-wire system, there is no such mechanical connection, and inputs from the driver, such as torque and steering angle, are detected by sensors, and in addition to information from other vehicle sensors, A suitable steering angle is obtained, the steering angle command value is sent to the steering actuator, and the wheels are actually steered.

  When adopting the steer-by-wire system, in order to ensure the steering performance when the system fails, a coupling mechanism that mechanically couples the steering wheel and the steered wheel separately from the steer-by-wire system, or a similar mechanism, It is common to prepare a mechanism for so-called fail-safe. As such a mechanism, for example, a steering device including a planetary gear clutch is known (see Patent Document 1).

JP 2009-04-0095 A

  However, in the steering device described in Patent Document 1, the steering wheel and the tire are connected via the planetary gear clutch even when the lock portion is opened, and the input from the road surface is transmitted to the steering wheel. Is done. Therefore, there is room for improvement in the feeling during steering.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a new clutch device capable of improving the steering feeling in the steering device.

  In order to solve the above-described problem, a clutch device according to an aspect of the present invention is a clutch device that performs torque transmission between two rotating shafts and switching between cutoffs, and a plurality of grooves are formed on the inner periphery or the outer periphery. A first rotating shaft formed in a circumferential direction with a gap; a second rotating shaft arranged coaxially with the first rotating shaft and overlapping at least partially; and the second rotating shaft A plurality of engaging portions provided on the second rotating shaft so as to be movable in a radial direction of the rotating shaft and arranged in the circumferential direction of the second rotating shaft at intervals, and the engaging portions An advancing / retreating mechanism for advancing / retreating in the direction toward the groove. The plurality of engaging portions include a first engaging portion that enters one of the plurality of groove portions and transmits torque in one rotational direction, and a second groove portion that is different from the first groove portion. And a second engagement portion that transmits torque in the other rotational direction. The first engagement portion, when torque is transmitted with a first torque in one rotational direction, a first engagement surface that engages with a first engaged surface that constitutes a side surface of the first groove portion; A second engagement surface that engages with a second engaged surface that is continuous with the first engaged surface when torque is transmitted with a second torque that is greater than the first torque in one rotational direction. . A first engaging surface that engages with a first engaged surface that constitutes a side surface of the second groove when the second engaging portion transmits torque with a first torque in the other rotational direction; A second engagement surface that engages with a second engaged surface that is continuous with the first engaged surface when torque is transmitted with a second torque that is greater than the first torque in the other rotational direction. . The second engagement portion is configured to engage with the second groove portion in a state where the first engagement portion is engaged with the first groove portion.

  According to this aspect, since the second engagement portion is also engaged with the second groove portion in a state where the first engagement portion is engaged with the first groove portion, no play is generated even when the rotation direction is switched. . That is, even when the steering is turned back to the other rotation direction in a state where torque is transmitted in one rotation direction, since the second engagement portion is already engaged with the second groove portion, Does not occur.

  The second engagement portion is configured such that the second engagement surface of the first engagement portion is engaged with the second engaged surface of the first groove portion. The first engagement surface may be configured to engage with the first engaged surface of the second groove portion. As a result, even when a large torque is being transmitted, there is no backlash when steering is turned back in the other rotational direction.

  When the first engagement portion transmits torque with the second torque in one rotational direction, the second engagement surface of the first engagement portion and the second engaged surface of the first groove portion In a state where the two are engaged, a force may be applied in a direction toward the bottom of the first groove. Thereby, when torque is transmitted with the second torque, the first engaging portion is prevented from coming out of the first groove portion.

  When the first engagement portion and the first groove portion are torque-transmitted by the second torque in one rotational direction, the second engagement surface of the first engagement portion and the first groove portion 2 You may be comprised so that a to-be-engaged surface may surface-contact. Thereby, when torque is transmitted with the second torque, the engagement state between the first engagement portion and the first groove portion is stabilized.

  When the first engagement portion and the first groove portion are torque-transmitted by the first torque in one rotational direction, the first engagement surface of the first engagement portion and the first groove portion One engaged surface may be configured to be in surface contact. Thereby, when torque is transmitted with the first torque, the engagement state between the first engagement portion and the first groove portion is stabilized.

  The first engaged surface of the first groove portion may be a slope connecting the side surface and the bottom surface of the first groove portion. Thereby, a 1st to-be-engaged surface can be easily formed in a groove part.

  The advance / retreat mechanism may include an urging unit that urges the first engagement portion and the second engagement portion toward the groove portion in a torque transmission state. Thereby, in a torque transmission state, a 1st engaging part and a 2nd engaging part can be made to contact | abut reliably to a groove part.

  According to the present invention, a new clutch device that can improve the steering feeling in the steering device can be realized.

It is a mimetic diagram showing a schematic structure of a vehicle steering device concerning a 1st embodiment. It is sectional drawing parallel to the axis | shaft of the clutch apparatus which concerns on 1st Embodiment. It is AA sectional drawing of the clutch apparatus shown in FIG. It is sectional drawing parallel to the axis | shaft of the clutch apparatus (clutch ON state) which concerns on 1st Embodiment. It is CC sectional drawing of the clutch apparatus shown in FIG. It is a figure for demonstrating the shape of a lock bar and a lock groove. It is the schematic diagram which showed the relationship between the lock bar and lock groove shown in FIG. 6 linearly. FIG. 6 is a cross-sectional view of the clutch device in which the handle side housing is slightly rotated in the direction of arrow R2 from the state shown in FIG. It is a figure for demonstrating the play in the clutch apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the clutch apparatus (clutch ON state) which concerns on 2nd Embodiment. It is an enlarged view of the area | region F1 of FIG. It is an enlarged view of the lock bar vicinity of FIG. It is a figure for demonstrating the state by which large torque was provided to the clutch apparatus which concerns on 2nd Embodiment. It is a figure for demonstrating the force which acts on a lock bar in the state which the 2nd engagement surface of a lock bar and the 2nd to-be-engaged surface of a lock groove are engaging. It is a figure for demonstrating the state before a lock is completed in the clutch apparatus which concerns on 3rd Embodiment. It is a figure for demonstrating the state which locked in the clutch apparatus which concerns on 3rd Embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The clutch device described in the following embodiments can be applied to a vehicle steering device. In particular, a so-called steer-by-wire vehicle steering device, that is, regardless of the steering force applied to an operation member such as a steering wheel provided in the steering unit, under the electrical control, by the power of the power source provided in the steering unit, This is suitable for a vehicle steering apparatus in which the wheels are steered according to the operation of the operation member.

(First embodiment)
FIG. 1 is a schematic diagram showing a schematic configuration of the vehicle steering apparatus according to the first embodiment. The vehicle steering apparatus 10 includes a steering wheel 12, a steering angle sensor 14, a torque sensor 16, a steering reaction force motor 18, an intermediate shaft 20, a turning angle sensor 22, a turning motor 24, and tires 26. The ECU 28 and the clutch device 29 are provided.

  The steering actuator 30 includes a steering angle sensor 14, a torque sensor 16, and a steering reaction force motor 18. The steering actuator 32 includes a steering angle sensor 22 and a steering motor 24. The ECU 28 controls the steering reaction force motor 18 and the steering motor 24 based on information from various sensors included in the steering actuator 30 and the steering actuator 32.

  The handle 12 is disposed on the driver's seat side in the passenger compartment and functions as a steering member that is rotated by the driver to input a steering amount.

  The steering angle sensor 14 detects the rotation angle of the handle 12 as the steering amount input by the driver, and outputs the detected value to the ECU 28. The steering angle sensor 14 functions as a detection unit that detects information according to the operation amount of the handle 12.

  The torque sensor 16 detects torque according to the steering amount of the handle 12. The steering reaction force motor 18 causes the handle 12 to apply a reaction force for causing the driver to feel a steering reaction force corresponding to the rotation angle of the handle 12 detected by the steering angle sensor 14 based on the control of the ECU 28.

  The ECU 28 includes, for example, a CPU, a ROM, a RAM, and a data bus that interconnects them. The ECU 28 detects a rotation angle of the steering wheel 12 as a steering amount input by the driver according to a program stored in the ROM, and performs this steering. It functions as a control means for calculating a turning amount based on the amount and controlling the turning motor 24 to turn the tire 26 based on the turning amount.

  The steered motor 24 constitutes a steered means for operating a rack bar extending in the vehicle width direction connected to the tire 26 via a tie rod in the vehicle width direction based on the control of the ECU 28.

  The turning angle sensor 22 detects the rotation angle of the pinion of the rack and pinion mechanism 34 that constitutes the turning means, and outputs the detected value to the ECU 28.

  The intermediate shaft 20 plays a role of transmitting a steering force (rotational force) from the steering actuator 30 to the steering actuator 32 as a part of a backup mechanism when the steer-by-wire system does not function. The mechanical backup mechanism includes an intermediate shaft 20, a clutch device 29, a rack and pinion mechanism 34, and the like.

  The clutch device 29 performs transmission / reception switching of torque (torque) between the two rotating shafts. Although details of the structure of the clutch device 29 will be described later, in the vehicle steering device 10, when the system is normal, the connection between the steering actuator 30 and the steered actuator 32 is separated by the clutch device 29. Function. On the other hand, when the system is abnormal, the vehicle steering device 10 can directly steer the tire 26 by operating the steering wheel 12 by mechanically connecting the steering actuator 30 and the steering actuator 32 by the clutch device 29. become.

  Next, the structure of the clutch device 29 will be described in detail. FIG. 2 is a cross-sectional view parallel to the axis of the clutch device 29 according to the first embodiment. 3 is a cross-sectional view taken along line AA of the clutch device 29 shown in FIG. 2 corresponds to the BB cross section shown in FIG.

  The clutch device 29 includes an annular handle-side housing 36 that is a first rotating shaft, an annular tire-side housing 38 that is a second rotating shaft, and a tire-side housing that can move in the radial direction of the tire-side housing 38. And a plurality of lock bars 40 serving as engaging portions provided on 38. The handle-side housing 36 has a plurality of lock grooves 42 formed on the inner peripheral surface thereof in the circumferential direction at intervals. The tire-side housing 38 is provided so as to be coaxial with the handle-side housing 36, and is disposed so that at least a part thereof overlaps the handle-side housing 36 when viewed from the side of the clutch device 29.

  The handle side housing 36 is connected to the steering actuator 30 and rotates in conjunction with the rotation of the handle 12. The tire-side housing 38 is connected to the steering actuator 32 and rotates in conjunction with the steering of the tire. The clutch device 29 further includes an advance / retreat mechanism 44 that advances and retracts the lock bar 40 in a direction toward the lock groove 42. Details of the advance / retreat mechanism 44 will be described later.

  In the clutch device 29 according to the present embodiment, five lock bars 40 are radially arranged at substantially equal intervals. Each lock bar 40 is slidably supported by an opening 38 a formed on the peripheral surface of the annular tire-side housing 38.

  A spring receiving member 46 is fixed in the vicinity of the opening on the right side shown in FIG. In the spring receiving member 46, a plurality of convex portions 46b are radially arranged at substantially equal intervals so as to correspond to the lock bars 40 on the outer peripheral surface of the small diameter portion 46a. The convex portion 46b supports one end thereof so that the spring 50, which is an urging member, does not shift. The other end of the spring 50 is supported by a recess 40 a formed in a portion of the lock bar 40 that faces the spring receiving member 46. The spring 50 is compressed in the state shown in FIGS.

  The advance / retreat mechanism 44 controls the advance / retreat of the lock bar 40 by acting on the lock bar 40 and the spring 50 that urges the lock bar 40 toward the lock groove 42 as an actuator driven by electricity. Pin 54 and an adapter 56 to which the pin 54 is fixed.

  The pull type solenoid 52 is configured such that the shaft 52a is pulled in when energized (clutch device is OFF), and the shaft 52a is projected by the action of a return spring inside when not energized (clutch device is ON). . FIG. 2 shows a state where the pull type solenoid 52 is energized.

  The pin 54 engages with the lock bar 40 in a state of entering a through hole 40 b provided in the center of the lock bar 40. Further, the pin 54 includes a first engagement portion 54a that comes into contact with the through hole 40b of the lock bar 40 when the clutch device is in the OFF state shown in FIG. 2, and a through hole 40b of the lock bar 40 that is described later with the clutch device ON. It has the 2nd engaging part 54b which contact | abuts, and the slope 54c which connects the 1st engaging part 54a and the 2nd engaging part 54b smoothly. The pin 54 is bent so as to approach the rotation axis Ax of the clutch device 29 from the second engagement portion 54b toward the first engagement portion 54a. Note that the second engagement portion 54b does not necessarily have to contact the inner peripheral wall of the through hole 40b.

  The adapter 56 is fixed to the shaft of the pull type solenoid 52, and its position changes in the axial direction according to the energized state of the pull type solenoid 52. At that time, the position of the pin 54 also changes in the axial direction.

  Next, the operation of the clutch device will be described. As shown in FIGS. 2 and 3, when the clutch device 29 is in an OFF state, that is, when the pull solenoid 52 is energized, the lock bar 40 and the lock groove 42 are not engaged at all. Therefore, the steering actuator 30 and the steering actuator 32 are separated from each other, and no rotational force is transmitted between them.

  More specifically, when the pull solenoid 52 is energized, the adapter 56 is pulled together with the shaft of the pull solenoid 52. At that time, the first engagement portion 54a of the pin 54 contacts the inner peripheral wall of the through hole 40b, and the lock bar 40 is restricted to a position where the clutch device 29 is in an OFF state.

  FIG. 4 is a cross-sectional view parallel to the axis of the clutch device 29 (clutch ON state) according to the first embodiment. 5 is a cross-sectional view of the clutch device 29 shown in FIG. 4 corresponds to the DD cross section shown in FIG.

  When the clutch device 29 is de-energized due to a system failure or the like and becomes non-energized, the adapter 56 that has been retracted moves to the right in FIG. 4 by the action of the return spring of the pull solenoid 52. As a result, the position of the pin 54 inside the through hole 40b of the lock bar 40 changes, and the second engaging portion 54b of the pin 54 is located inside the through hole 40b. As a result, the lock bar 40 whose position is regulated by the pin 54 can move toward the lock groove 42 of the handle side housing 36.

  As described above, each lock bar 40 is subjected to a force that moves in the radial direction of the tire-side housing 38 toward the lock groove 42 of the handle-side housing 36 by the urging force of the spring 50. As shown in FIG. The device 29 is not configured so that all the lock bars 40 enter the lock grooves 42 as they are.

  That is, depending on the positional relationship between each lock bar 40 (hereinafter sometimes referred to as lock bars 401 to 405 as appropriate) and each lock groove 42, that is, the positional relationship between the handle-side housing 36 and the tire-side housing 38, The combination of lock bars that enter the groove 42 can vary. In the clutch device 29 shown in FIG. 5, lock bars 401 to 403 that enter the lock groove 42, and lock bars 404 and 405 that do not enter the lock groove 42 and are in contact with the protrusion 43 between the lock grooves 42. Will exist.

  The state shown in FIG. 5 is a case where the clutch device 29 is completely turned on, but this state is not always reached at the same time as the energization of the pull solenoid 52 is released. Hereinafter, the operation until the clutch device 29 is completely turned on by the normal operation of the handle 12 will be described in more detail.

  FIG. 8 is a cross-sectional view of the clutch device in which the handle side housing 36 is slightly rotated in the direction of arrow R2 from the state shown in FIG. For example, when the handle side housing 36 is in a position slightly rotated in the direction of arrow R2 from the state shown in FIG. 5 (the tire side housing 38 remains in the state shown in FIG. 5), the lock bars 401 and 402 have the lock groove 42. Although entering, the lock bars 403, 404, 405 are in contact with the protrusion 43 on the inner peripheral wall of the handle-side housing 36. In this case, the lock bars 401 and 402 that have entered the lock groove 42 are not in contact with the side surfaces 42 a and 42 b of the lock groove 42. Therefore, there is play in the rotational direction between the handle-side housing 36 and the tire-side housing 38.

  When the handle housing 36 is rotated in the direction of the arrow R1 from this state, the lock bar 403 enters the lock groove 42 when the lock bar 401 contacts and engages one side surface 42a of the lock groove 42, and the lock groove 401 The other side surface 42b of 42 is engaged. As a result, as shown in FIG. 5, the lock bar 401 that enters the lock groove 421 and engages the one side surface 42a and the lock bar 403 that enters the lock groove 423 and engages the other side surface 42b, The play in the rotational direction between the housing 36 and the tire side housing 38 is substantially eliminated (locked state), and the rotational force of the handle side housing 36 can be reliably transmitted to the tire side housing 38.

  Thus, in the clutch device 29 according to the present embodiment, when the plurality of lock bars 40 are moved toward the plurality of lock grooves 42 by the advance / retreat mechanism 44 including the pull type solenoid 52, the handle side housing 36 and the tire Regardless of the rotational phase difference with the side housing 38, the lock bar 401 entering the lock groove 421, which is one of the plurality of lock grooves 42, and the lock bar 401 entering the lock groove 421 Is moved in the counterclockwise direction of rotation (in the direction of arrow R2 shown in FIG. 8) and engaged with one of the two side surfaces 42a and 42b of the lock groove 421 on the side surface 42a in the direction of rotation (in the direction of arrow R2). And a lock bar 403 that enters a lock groove 423 as a second groove portion different from the lock groove 421. When the lock bar 403 enters the lock groove 423, the lock bar 403 is configured to engage with the side surface 42b on the other rotation direction (arrow R1 direction) side of the two side surfaces 42a and 42b of the lock groove 423.

  Thus, the clutch device 29 retracts each lock bar 40 from the lock groove 42 by the advance / retreat mechanism 44, so that the vehicle steering device 10 is in a separated state in which no rotational force is transmitted between the handle side housing 36 and the tire side housing 38. Can be. On the other hand, the clutch device 29 rotates in one rotation direction (for example, the direction of the arrow R1) when the handle side housing 36 and the tire side housing 38 are connected by the advance / retreat mechanism 44 (locked state). In this case, since the lock bar 401 is engaged with the side surface 42a on the other rotation direction (arrow R2 direction) side of the two side surfaces of the lock groove 421, the rotational force is exerted with little play. 38. When the handle-side housing 36 rotates in the other rotation direction (for example, the direction of the arrow R2), the lock bar 403 moves to the side surface 42b on the one rotation direction (the direction of the arrow R1) of the two side surfaces of the lock groove 423. Because of the engagement, the rotational force can be transmitted to the tire-side housing 38 with little play.

  Further, the clutch device 29 retracts the lock bar 40 from the lock groove 42 with a force larger than the urging force of the spring 50 by the operation when the pull solenoid 52 is energized, and the energization to the pull solenoid 52 is released. In this case, the lock bar 402 and the lock bar 403 are configured to enter the lock groove 42 by the urging force of the spring 50. As a result, in an emergency where the pull solenoid 52 is no longer energized, the lock bar 402 and the lock bar 403 enter the lock groove 42 to immediately connect the handle side housing 36 and the tire side housing 38. .

  Next, a preferred relationship between the lock bar 40 and the lock groove 42 will be described. FIG. 6 is a view for explaining the shapes of the lock bar 40 and the lock groove 42. FIG. 7 is a schematic diagram showing the relationship between the lock bar and the lock groove shown in FIG. 6 in a straight line.

  As shown in FIGS. 6 and 7, the number of the plurality of lock grooves 42 is n [pieces], the pitch of the lock grooves 42 is P, the number of the plurality of lock bars 40 is N [pieces], and the plurality of lock grooves 42 are The number of lock bars 40 to be entered is Nx [pieces], the width of the lock bar 40 is W [deg], the width of the lock groove 42 is B1 [deg], and the distance between the lock groove 42 and the adjacent lock groove 42 (projection 43 Parameter) in the clutch device 29 according to the present embodiment, where B2 [deg] is B2 [deg], and a deviation angle (displacement angle at the time of connection) when the lock bar 40 is engaged with the lock groove 42 is δ [deg]. Is set as shown in Table 1.

Each parameter is P = 360 / n (1)
B1≈W + (δ × (Nx−1)) (2)
δ = P / N (3)
It is set to satisfy each formula of It should be noted that the numerical values in each equation can be allowed to have some errors depending on the degree of freedom of design and the tolerance of parts.

  As a result, at least one lock bar 40 can always enter the lock groove 42 regardless of the relative phase between the handle-side housing 36 and the tire-side housing 38. In addition, a design in consideration of a deviation angle δ at the time of connecting (locking) the handle side housing 36 and the tire side housing 38 is possible. Here, the displacement angle δ at the time of connection means that one of the relative phases of the handle-side housing 36 and the tire-side housing 38 can be rotated with respect to the other by the displacement angle δ at the time of connection. For example, it is a parameter indicating an angle at which the clutch ON state (locked state) is realized in the clutch device 29. That is, if the deviation angle δ at the time of connection is set to be small, the steering actuator 30 and the steering actuator 32 are mechanically coupled by a slight steering operation even when the system is abnormal. Responsiveness is improved.

  As described above, the vehicle steering apparatus 10 includes the handle 12 (steering member) that is rotated to steer the vehicle, the steering angle sensor 14 (detection means) that detects information according to the operation amount of the handle 12, A rack and pinion mechanism 34 (steering mechanism) that steers the tire 26, a steering motor 24 (power source) that drives the rack and pinion mechanism 34, and the handle 12 and the rack and pinion mechanism 34 are disposed. , A clutch device 29 that performs transmission of torque between the handle 12 and the rack and pinion mechanism 34 and switching between cutoffs, and the steering motor 24 is driven in a state in which the torque is interrupted by the clutch device 29. ECU28 (control means) which controls the amount of steering based on the information according to. The handle 12 is connected to the handle side housing 36, the rack and pinion mechanism 34 is connected to the tire side housing 38, and the clutch device 29 is a rotational force between the handle 12 and the rack and pinion mechanism 34. The handle side housing 36 and the tire side housing 38 are mechanically connected so that the steering angle of the wheel changes in accordance with the operation of the handle 12 in a state where can be transmitted.

  Thus, when the turning motor 24 is driven in a state where the rotational force is interrupted by the clutch device 29 and the turning amount is controlled based on the information corresponding to the operation amount of the handle 12, the rack and pinion Since torque fluctuation or the like is not transmitted from the mechanism 34 to the handle 12, the steering feeling can be improved.

(Second Embodiment)
In the clutch device 29 according to the first embodiment, in consideration of the dimensional tolerance of each component such as the lock bar, the lock groove, and each housing, the handle side housing and the tire side housing are connected (lock state). Even so, it is inevitable that rattling occurs when the handle is turned back. FIG. 9 is a view for explaining backlash in the clutch device 29 according to the first embodiment. As shown in FIG. 9, the clutch device 29 is in a locked state in which the lock bar 401 enters the lock groove 421, the lock bar 403 enters the lock groove 423, and the lock bar 401 and the lock groove 421 are engaged. However, a gap g exists between the lock bar 403 and the lock groove 423. For this reason, if the handle side housing 36 is turned back in the direction of the arrow R2 in this state, rattling occurs until the lock bar 403 is engaged with the lock groove 423.

  Therefore, in the present embodiment, a clutch device that is configured to suppress the occurrence of rattling when the handle is turned back and that does not disengage the lock bar from the lock groove even when a large torque is input in the locked state. To do.

  Specifically, the clutch device according to the present embodiment sets the two engagement surfaces with different angles as the shapes of the engagement portions of the lock bar and the lock groove, so that “backlash elimination at the time of switching” is obtained. It is possible to achieve both “prevention of lock state release when large torque is applied”.

  FIG. 10 is a diagram for explaining the clutch device (clutch ON state) according to the second embodiment. FIG. 11 is an enlarged view of a region F1 in FIG. FIG. 12 is an enlarged view of the vicinity of the lock bar 603 of FIG.

  The clutch device 58 shown in FIG. 10 has substantially the same configuration as the clutch device 29 according to the first embodiment except that the shapes of the lock bar and the lock groove are different.

  The clutch device 58 performs torque transmission and switching between the handle-side housing 36 and the tire-side housing 38 that are two rotating shafts. The clutch device 58 includes a handle-side housing 36 as a first rotating shaft in which a plurality of groove portions, which are a plurality of groove portions, are formed in the circumferential direction at intervals on the inner periphery, and coaxial with the handle-side housing 36. The tire-side housing 38 serving as a second rotating shaft that is arranged so that at least a part thereof overlaps, and the tire-side housing 38 so as to be movable in the radial direction of the tire-side housing 38, are spaced apart from each other. A lock bar 60 as a plurality of engaging portions arranged in the circumferential direction of the side housing 38 and an advance / retreat mechanism 44 (see FIG. 2) for moving the lock bar 60 in the direction toward the lock groove 62 are provided.

  Next, the relationship between the tip shape of the lock bar 60 and the shape of the lock groove 62 will be described. As shown in FIG. 11, the lock bar 60 includes a first engagement surface 60a and a second engagement surface 60b that is continuous with the first engagement surface 60a. The second engagement surface 60b is formed to be substantially parallel to the moving direction of the lock bar 60. The first engagement surface 60a is formed obliquely with respect to the second engagement surface 60b, and the width of the lock bar 60 becomes narrower toward the tip.

  On the other hand, the inner wall (side wall) in the rotation direction of the lock groove 62 includes a first engaged surface 62a and a second engaged surface 62b continuous with the first engaged surface 62a. The second engaged surface 62 b is formed so as to be substantially parallel to the radial direction of the handle side housing 36. The first engaged surface 62a is formed obliquely with respect to the lock bar 60, and the groove width of the lock groove 62 becomes narrower toward the bottom.

  Next, the operation at the time of normal steering force of the clutch device 58 (at the time of torque transmission with the first torque) will be described. When the lock of the clutch device 58 is activated under a predetermined condition, as shown in FIG. 10, the lock bar 601 and the lock bar 602 enter the corresponding lock groove 621 and the lock groove 622, respectively, and move to the maximum stroke. The lock bar according to the present embodiment is set so as not to hit the bottom of the lock groove even when the lock bar moves to the maximum stroke.

  When the handle side housing 36 further rotates in the direction of the arrow R1, the lock bar 603 also enters the lock groove 623. At that time, the lock bar 603 engages with the side of the lock groove 623 before reaching the maximum stroke with respect to the lock groove 623.

  As described above, the plurality of lock bars 60 included in the clutch device 58 enter the lock groove 621 among the plurality of lock grooves 62 and perform the torque transmission in one rotation direction (arrow R1 direction) of the handle side housing 36. And a lock bar 603 that enters the lock groove 623 different from the lock groove 621 and transmits torque in the other rotation direction (arrow R2 direction) of the handle-side housing 36.

  The lock bar 601 is a first engaged member that forms the side surface of the lock groove 621 when torque is transmitted with a first torque smaller than a predetermined threshold in one rotation direction of the handle-side housing 36 (in the direction of arrow R1). It has the 1st engagement surface 601a engaged with the mating surface 621a. In addition, the lock bar 603 is a first engagement member that forms the side surface of the lock groove 621 when torque is transmitted with a first torque smaller than a predetermined threshold in the other rotation direction (arrow R2 direction) of the handle-side housing 36. It has the 1st engagement surface 603a engaged with the mating surface 623a.

  When the torque is transmitted with the first torque in one rotation direction, the lock bar 601 and the lock groove 621 face the first engagement surface 601a of the lock bar 601 and the first engaged surface 621a of the lock groove 621. It is comprised so that it may contact. Thereby, when torque is transmitted with the first torque, the engagement state between the lock bar 601 and the lock groove 621 is stabilized.

  Thus, in the clutch device 58, the lock bar 603 is also engaged with the lock groove 623 (see FIG. 10) in a state where the lock bar 601 is engaged with the lock groove 621 (see region F2 in FIG. 10). Region F3, see FIG. 12). The spring 50 provided in the advance / retreat mechanism urges the lock bar 601 and the lock bar 603 toward the groove in the torque transmission state. Thereby, in a torque transmission state, a 1st engaging part and a 2nd engaging part can be made to contact | abut reliably to a groove part. Therefore, there is no play when the rotation direction is switched. That is, the lock bar 603 is already engaged with the lock groove 623 even when the steering is turned back in the direction of the arrow R2 while the handle side housing 36 is rotated in the direction of the arrow R1 and torque is transmitted. Therefore, no play occurs.

  As shown in FIG. 10, when torque is transmitted from the handle side housing 36 in the direction of the arrow R <b> 1, the lock bar 601 protrudes most from the tire side housing 38 (maximum stroke). A movement restricting portion 38 b that restricts the movement of the lock bar 601 is formed on the inner peripheral side of the tire-side housing 38 by abutting the large-diameter portion 601 c of the lock bar 601. When the first engagement surface 601a of the lock bar 601 is engaged with the first engaged surface 621a of the lock groove 621, the lock bar 603 is also engaged with the lock groove 623. The large diameter portion 603c is configured not to contact the movement restricting portion 38b of the tire side housing 38 (see the region F4). That is, the lock bar 603 is configured such that the radial movement is not restricted by the tire-side housing 38 and can further move toward the lock groove 623.

  Thus, even if the clutch device 58 is in a state where the lock bars (601, 603) corresponding to the plurality of lock grooves (621, 623) are engaged, at least one of the plurality of lock bars is It is comprised so that it may not contact | abut with the movement control part 38b of the tire side housing 38. FIG. Thereby, the play at the time of turning back the handle can be surely eliminated.

  Next, a case where a large torque is applied to the clutch device 58 shown in FIG. 10 (a case where torque is transmitted using the second torque) will be described. FIG. 13 is a diagram for explaining a state in which a large torque is applied to the clutch device according to the second embodiment.

  When a larger torque (in the direction of arrow R1) is applied from the state shown in FIG. 10, the lock bar 601 that has been engaged with the first engaged surface 621a of the lock groove 621 is moved into the first engaged state of the lock groove. It receives drag from the surface 621a. The first engaged surface 621 a is formed obliquely with respect to the stroke direction of the lock bar 601. That is, the first engaged surface 621a is a slope connecting the second engaged surface 621b and the bottom surface 621c, which are side surfaces of the lock groove 621. Therefore, the component force of the drag also works in the stroke direction of the lock bar 601. If the component force is greater than the urging force of the spring 50, the spring 50 is compressed, and the lock bar 601 slides toward the center of the rotation axis while sliding on the first engaged surface 621a, thereby restricting the movement of the tire-side housing 38. A gap is generated between the portion 38b (see region F5).

  When the second engagement surface 601b comes into contact (engagement) with the second engaged surface 621b of the lock groove 621, the lock bar 601 maintains its position without sliding any further, so that a large torque can be transmitted. Done. At this time, the lock bar 603 may be configured such that the first engagement surface 603 a is engaged with the first engaged surface 623 a of the lock groove 623. As a result, even when a large torque is being transmitted, rattling does not occur when steering is turned back in the other rotational direction (arrow R2).

  When the torque is transmitted with the second torque in one rotation direction, the lock bar 601 and the lock groove 621 face the second engagement surface 601b of the lock bar 601 and the second engaged surface 621b of the lock groove 621. It is comprised so that it may contact. Thereby, when torque is transmitted with the second torque, the engagement state between the lock bar 601 and the lock groove 621 is stabilized.

  Next, the shape of the second engaged surface 62b of the lock groove 62 will be further described in detail. FIG. 14 is a diagram for explaining a force acting on the lock bar 601 in a state where the second engagement surface 601b of the lock bar 601 and the second engaged surface 621b of the lock groove 621 are engaged.

As described above, when a large torque is applied to the clutch device 58, the second engagement surface 601b of the lock bar 601 and the second engaged surface 621b of the lock groove 621 are engaged. Here, the torque is T ₀ , the contact position radius between the lock bar 601 and the lock groove 621 is r, the drag that the lock bar 601 receives from the second engaged surface 621 b of the lock groove is f ₁ , and the second of the lock bar 601 is The frictional force between the engagement surface 601 b and the second engaged surface 621 b of the lock groove 621 is f ₂ , the friction coefficient is μ ₁ , the contact position between the lock bar 601 and the lock groove 621, and the center line of the lock bar 601. When the angle formed is θ ₀ (θ ₀ > 0 °), the following expressions (1) to (3) exist.
F ₀ = T ₀ / r (1)
F ₀ = f ₁ × cos θ ₀ + f ₂ × sin θ ₀ (2)
f ₂ = μ ₁ × f ₁ Formula (3)

From the equations (1) to (3), the drag force f ₁ and the friction force f ₂ are f ₁ = F ₀ / (cos θ ₀ + μ ₁ × sin θ ₀ ) (4)
f ₂ = μ ₁ × F ₀ / (cos θ ₀ + μ ₁ × sin θ ₀ ) (5)
It is expressed. Therefore, if θ ₀ > 0, the drag force f ₁ and the friction force f ₂ are both positive, and the lock bar 601 receives a force toward the lock groove 621 as shown in FIG. Even when torque is applied, the lock bar is prevented from coming out of the lock groove.

  As described above, when the lock bar 601 and the lock groove 621 are transmitted with a large torque in one rotational direction, the second engagement surface 601b and the second engaged surface 621b are engaged with each other. A force is applied in a direction toward the bottom of the lock groove 621.

(Third embodiment)
The clutch device according to the third embodiment is a modification of the clutch device according to the second embodiment. FIG. 15 is a diagram for explaining a state before locking is completed in the clutch device according to the third embodiment. FIG. 16 is a diagram for explaining a state in which locking is completed in the clutch device according to the third embodiment.

  First, the operation of the clutch device 64 will be described. When the clutch device 64 is locked under a predetermined condition, as shown in FIG. 15, the lock bar 601 and the lock bar 602 enter the corresponding lock groove 621 and the lock groove 622, respectively, and move to the maximum stroke. At this time, the first engagement surface 601a of the lock bar 601 and the first engaged surface 621a of the lock groove 621 are engaged, but at that time, the lock bar 603 does not enter the lock groove 623. Yes.

  When the handle side housing 36 is rotated in the arrow R1 direction in this state, the lock bar 601 slides against the spring 50 while sliding on the first engaged surface 621a of the lock groove 621, as shown in FIG. As described above, the lock bar 603 enters the lock groove 623. When the handle-side housing 36 is further rotated in the arrow R1 direction, the lock bar 601 second engagement surface 601b is engaged with the second engaged surface 621b of the lock groove 621, and torque transmission is performed. At this time, the lock bar 603 is in contact with the first engaged surface 623 a of the lock groove 623. Further, neither the lock bar 601 nor the lock bar 603 has moved up to the maximum stroke, and is in a state where it can move toward the lock groove. Therefore, even if the handle 12 is turned back in any direction, a reaction force is received from the lock bar, so that torque is not felt.

  As described above, the present invention has been described with reference to the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and the configurations of the embodiments are appropriately combined or replaced. Those are also included in the present invention. Further, it is possible to appropriately change the combination and processing order in each embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to each embodiment. Embodiments to which is added can also be included in the scope of the present invention.

  In each of the above-described embodiments, the clutch device in which the lock groove is provided in the inner periphery of the handle side housing and the lock bar is provided in the tire side housing has been described. However, the lock bar is provided in the handle side housing and the tire is provided. A clutch device in which a lock groove is provided on the outer periphery of the side housing may be used. In addition, the names of “engagement surface” and “engaged surface” in each of the above-described embodiments merely indicate a relative relationship, and opposite names may be given to the respective parts. .

  DESCRIPTION OF SYMBOLS 10 Vehicle steering device, 12 Steering wheel, 14 Steering angle sensor, 16 Torque sensor, 18 Steering reaction force motor, 20 Intermediate shaft, 22 Steering angle sensor, 24 Steering motor, 26 Tire, 28 ECU, 29 Clutch device, 30 Steering actuator, 32 Steering actuator, 34 Rack and pinion mechanism, 36 Handle side housing, 38 Tire side housing, 38a Opening part, 38b Movement restricting part, 50 Spring, 58 Clutch device, 60 Lock bar, 60a First engagement surface 60a, 60b second engagement surface, 62 lock groove, 62a first engaged surface, 62b second engaged surface, 601 lock bar, 601a first engagement surface, 601b second engagement surface, 601c large Diameter, 602 03 locking bar, 603a first engaging surface, 603c large diameter portion, 621 lock groove, 621a first engaged surface, 621b second engaging surface, 621c bottom 623 lock groove.

Claims (7)

A clutch device that performs torque transmission and switching between two rotating shafts,
A first rotating shaft in which a plurality of grooves are formed circumferentially at intervals on the inner periphery or outer periphery;
A second rotating shaft arranged coaxially with the first rotating shaft and at least partially overlapping;
A plurality of engaging portions provided on the second rotating shaft so as to be movable in a radial direction of the second rotating shaft, and arranged in the circumferential direction of the second rotating shaft at intervals from each other;
An advancing / retreating mechanism for advancing and retracting the engaging portion in a direction toward the groove portion,
The plurality of engaging portions are
A first engagement portion that enters one of the plurality of groove portions and transmits torque in one rotational direction; and
A second engagement portion that enters a second groove portion different from the first groove portion and transmits torque in the other rotational direction,
The first engagement portion, when torque is transmitted with a first torque in one rotational direction, a first engagement surface that engages with a first engaged surface that constitutes a side surface of the first groove portion; A second engagement surface that engages with a second engaged surface that is continuous with the first engaged surface when torque is transmitted with a second torque that is greater than the first torque in one rotational direction. And
A first engaging surface that engages with a first engaged surface that constitutes a side surface of the second groove when the second engaging portion transmits torque with a first torque in the other rotational direction; A second engagement surface that engages with a second engaged surface that is continuous with the first engaged surface when torque is transmitted with a second torque that is greater than the first torque in the other rotational direction. And
The second engagement portion is configured to engage with the second groove portion in a state where the first engagement portion is engaged with the first groove portion.
A clutch device characterized by that.   The second engagement portion is configured such that the second engagement surface of the first engagement portion is engaged with the second engaged surface of the first groove portion. The clutch device according to claim 1, wherein the first engagement surface is configured to engage with the first engaged surface of the second groove portion.   When the first engagement portion transmits torque with the second torque in one rotational direction, the second engagement surface of the first engagement portion and the second engaged surface of the first groove portion 3. The clutch device according to claim 1, wherein a force is applied in a direction toward the bottom of the first groove portion in a state where the two are engaged.   When the first engagement portion and the first groove portion are torque-transmitted by the second torque in one rotational direction, the second engagement surface of the first engagement portion and the first groove portion The clutch device according to claim 3, wherein the clutch device is configured to be in surface contact with the two engaged surfaces.   When the first engagement portion and the first groove portion are torque-transmitted by the first torque in one rotational direction, the first engagement surface of the first engagement portion and the first groove portion The clutch device according to any one of claims 1 to 4, wherein the clutch device is configured to be in surface contact with one engaged surface.   The clutch device according to any one of claims 1 to 5, wherein the first engaged surface of the first groove portion is an inclined surface that connects a side surface and a bottom surface of the first groove portion.   The said advancing / retreating mechanism has urging means for urging the first engaging portion and the second engaging portion toward the groove portion in a torque transmission state. The clutch device according to item.

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