JP2008308054A - Vehicular steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make control of the clearance of a clutch easy and to improve operation feeling in a vehicular steering device. <P>SOLUTION: An electromagnetic clutch 8 comprises an inner circumference surface rotor 17 joined to the end surface of an output pulley 15 connected to a pinion shaft, an outer circumference surface rotor 18 having an outer circumference surface rolling on an inner circumference surface of the inner circumference surface rotor 17, an annular space 22 between a cylindrical part 17b integrally formed in the center part of the inner circumference surface rotor 17 and a circular hole 18b formed in the center part of the outer circumference surface rotor 18, a pair of wedges 20 arranged in the annular space 22 with base ends opposing to each other, a drive pin 23 existing between the base ends of the pair of wedges 20 and protrudingly formed in an end surface of a connecting shaft 13, leaf springs 21 energizing the pair of wedges 20 toward mutually separating direction, and a pair of unlocking pins 28 arranged to move forward and backward from the end surface of the connecting shaft 13 to the tip of the respective wedge 20 and unlocking by pressing the pair of wedges 20 toward mutually approaching direction resisting the energizing force of the leaf springs 21. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention converts the rotational speed of the steering wheel into an electrical signal in a state where the mechanical connection between the steering wheel and the steering mechanism that converts the rotational motion of the steering wheel into reciprocating motion is disconnected, and based on the electrical signal The present invention relates to a vehicle steering apparatus that employs a so-called steer-by-wire (SBW) system that drives a rack that constitutes a steering mechanism to steer wheels.

  As a conventional vehicle steering apparatus adopting a steer-by-wire (SBW) system, there is one disclosed in Patent Document 1. A vehicle steering apparatus 1 disclosed in Patent Document 1 includes a steering wheel 2 that is rotated by a driver, a steering angle sensor 3 that detects the rotation direction and the number of rotations of the steering wheel 2 as electrical signals, and the steering A steer-by-wire control unit 9 that rotationally controls a steering motor (not shown) based on an electric signal of the angle sensor 3 and a wheel angle conversion mechanism as a steering mechanism that converts the rotational motion of the steering motor into a reciprocating motion to steer the wheel. 6 and an electromagnetic clutch mechanism 8 that mechanically connects and disconnects the steering wheel 2 and the wheel angle conversion mechanism 6.

  As shown in FIGS. 1 to 4 of Patent Document 1, the electromagnetic clutch mechanism 8 is connected to the wheel angle conversion mechanism 6 via the cable 13 and the upper shaft 13 of FIG. 2 connected to the steering wheel 2. 2 is connected to and disconnected from the lower output pulley 15 in FIG. 2, and the inner peripheral tooth portion 17a of the inner peripheral gear body 17 coupled to the upper surface of the output pulley 15 is in a floating state. The outer peripheral tooth 18a of the outer peripheral gear body 18 is meshed at one place on the circumference. When the spool 23 does not protrude between the pair of lock pieces 20a urged in the opening direction by the ring-shaped spring 21, only the pair of lock pieces 20a is driven by the drive protrusion 16 protruding downward in the axial direction from the shaft 13. The drive protrusion 16 that is driven to rotate and protrudes from the shaft 13 with respect to the inner peripheral gear body 17 of the output pulley 15 rotates idly, so that the electromagnetic clutch mechanism 8 is in a disconnected state. On the other hand, when the spool 23 protrudes downward in the axial direction from the shaft 13, the pair of lock pieces 20a, the outer peripheral gear body 18, and the inner peripheral gear body 17 are integrated with each other due to the wedge effect of the pair of lock pieces 20a. As a result, the driving protrusion 16 protruding from the shaft 13 rotates the inner peripheral gear body 17 of the output pulley 15 and the electromagnetic clutch mechanism 8 is in a connected state.

  Under normal conditions, the electromagnetic coil 27 of the electromagnetic clutch mechanism 8 is energized under the control of the steer-by-wire control unit 9, so that the electromagnetic coil 27 attracts the spool 23 against the biasing force of the spring 25 and the electromagnetic clutch mechanism 8. Is in a disconnected state, and the steering wheel 2 and the wheel angle conversion mechanism 6 are disconnected. When the steering wheel 2 is rotated, the steer-by-wire control unit 9 rotationally drives the steering motor according to the rotational speed of the steering wheel 2 detected by the steering angle sensor 3, and the rotational motion of the steering motor is changed to the wheel. It is converted into a reciprocating motion by the angle conversion mechanism 6 and a wheel (not shown) is steered.

  When the steer-by-wire control unit 9 determines that the steering motor has failed, the steer-by-wire control unit 9 stops energization of the electromagnetic coil 27, so that the spool 23 is paired with a pair of lock pieces by the biasing force of the spring 25. Advance toward 20a. For this reason, while the electromagnetic clutch mechanism 8 will be in a connection state, the drive of the steering motor by the electric quantity which the steering angle sensor 3 detected is stopped. As a result, the operating force of the steering wheel 2 is transmitted to the wheel angle conversion mechanism 6 via the electromagnetic clutch mechanism 8, and the wheel angle conversion mechanism 6 converts the rotational motion into a reciprocating motion to steer a wheel (not shown).

As described above, in the steer-by-wire (SBW) type vehicle steering apparatus, the electromagnetic clutch mechanism 8 is in a connected state by stopping energization at the time of a system failure, and the vehicle steering apparatus functions normally even in the unlikely event. .
JP 2007-22460 A

  However, in the invention described in Patent Document 1 in which the clutch is connected by the bite of the wedge, it is necessary to manage the gap, and the gap is required to have high accuracy, so that the management becomes complicated. In addition, since there is a gap between the pair of lock pieces and the spool, there is a problem that the steering wheel operation feeling is poor. That is, in FIG. 4 of Patent Document 1, when the spool 23 does not jump between the base end portions of the pair of lock pieces 20a during normal operation, the base end portions of the pair of lock pieces 20a. The pair of lock pieces 20a is pushed by the drive protrusions 16 and idles in a state where the gap G1 between them is larger than the gap G2 between the distal ends of the pair of lock pieces 20a and the drive protrusions 16. 23 jumps between the base end portions of the pair of lock pieces 20a, and the pair of lock pieces 20a move away from each other, and the pair of lock pieces 20a, the inner peripheral gear body 17, and the outer peripheral gear are moved by the wedge effect. When the body 18 becomes relatively unmovable and the spool 23 drives the inner peripheral gear body 18 and a large torque is transmitted, a gap G3 between the spool 23 and the base end portions of the pair of lock pieces 20a is generated. , Rock It is smaller than the gap G2 between the drive projection 16 and the tip piece 20a. Even when the spool 23 is pushed between the pair of lock pieces 20a, the gap G3 needs to be set to be smaller than the gap G2. As described above, since the gaps G1, G2, and G3 exist and the sizes of the gaps G1, G2, and G3 need to be managed, a high system is required and the management becomes complicated. Further, since the gap G3 between the pair of lock pieces 20a and the spool 23 is felt as play of the steering wheel, the operation feeling of the steering wheel is deteriorated.

  Therefore, an object of the present invention is to provide a vehicle steering apparatus that solves such a problem and reduces the management of the gap to improve the operation feeling.

  The invention according to claim 1 is provided with a steering actuator that is driven by an amount corresponding to a detected value obtained by detecting the rotation speed of the steering wheel, and the steering actuator is connected to a rack that can reciprocate in the left-right direction of the vehicle body. While both ends of the rack are connected to wheels, a pinion shaft is connected to the steering wheel via a clutch that performs mechanical connection and disconnection, and a pinion provided on the pinion shaft is engaged with the rack, and the clutch Includes an inner peripheral surface forming member coupled to one end surface of an input shaft connected to the steering wheel and an output shaft connected to the pinion shaft, the end surfaces being opposed to each other, and the inner peripheral surface An outer peripheral surface forming member having an outer peripheral surface rolling on the inner peripheral surface of the forming member, a cylindrical portion integrally provided at the center of the inner peripheral surface forming member, and the outer peripheral surface An annular space formed between a circular hole formed in the central portion of the component member, a pair of wedges provided in the annular space and having wide base ends opposed to each other, and the pair of wedges A driving pin interposed between the base end portions of the input shaft and projectingly formed on the other end surface of the input shaft or the output shaft, and a biasing force for locking by urging the pair of wedges away from each other And the pair of wedges close to each other against the urging force of the locking urging means provided to be able to advance and retreat from the other end face of the input shaft or the output shaft to the tip of each wedge. A pair of unlocking pins that are unlocked by pressing in the direction are provided.

  According to the present invention, in the steer-by-wire mode that is a normal use state, the number of rotations of the steering wheel is detected, the steering actuator is driven by an amount corresponding to the detected value by the detection, and the rack is driven by the driving of the steering actuator. The vehicle moves back and forth in the left-right direction, and the wheels are steered by the rack. At this time, since the lock release pins of the clutch protrude toward the front ends of the respective wedges, the pair of wedges are pressed toward each other against the urging force of the urging means for locking and unlocked. The pair of wedges in the unlocked state are rotationally driven by the drive pins and rotate freely between the inner peripheral surface forming member and the outer peripheral surface forming member. Therefore, the rotation is not transmitted from the input shaft provided with the drive pin to the output shaft provided with the inner peripheral surface forming member, and the clutch is disengaged.

  When the lock release pin moves backward in the event of an abnormality, the locking biasing means biases the pair of wedges away from each other, so that the pair of wedges, the inner peripheral surface forming member, and the outer peripheral surface forming member cannot rotate relative to each other due to the wedge effect. The locked inner peripheral surface forming member is rotated by the drive pin. Therefore, rotation is transmitted from the input shaft provided with the drive pin to the output shaft provided with the inner peripheral surface forming member, and the clutch is brought into a connected state. By connecting the clutch, the steering wheel and the pinion shaft are mechanically directly connected to enter the direct connection mode. In the direct connection mode, the pinion shaft is directly rotated from the steering wheel without using the steering actuator, and the pinion shaft rotates. Is converted into a reciprocating motion of the rack, and the wheels are steered.

  According to a second aspect of the present invention, in the vehicle steering apparatus according to the first aspect, the inner peripheral surface forming member and the outer peripheral surface forming member are arranged such that the outer peripheral surface is in rolling contact with the inner peripheral surface. It is a peripheral surface rotating body and an outer peripheral surface rotating body.

  According to the present invention, since the inner peripheral surface rotating body and the outer peripheral surface rotating body are in rolling contact with each other and transmit the rotation at the contact portion, the manufacturing cost is reduced by the amount not requiring gear machining. Further, in the case of meshing contact between gears, accuracy is required so as not to be caught when the mesh is disengaged, but accuracy is not required because of rolling contact. Furthermore, in the case of meshing contact, since accuracy is required, the amount of eccentricity between the internal gear and the external gear is limited. However, in the case of the inner peripheral surface rotating body and the outer peripheral surface rotating body, accuracy is not required. The amount of eccentricity is not limited, and the transmission torque can be increased by reducing the amount of eccentricity and reducing the angle of the rust, and the degree of freedom in design is high.

  According to a third aspect of the present invention, in the vehicle steering apparatus according to the first aspect, the inner peripheral surface forming member and the outer peripheral surface forming member are configured such that the outer peripheral surface is in meshing contact with the inner peripheral surface. It is a toothed gear and an external gear.

  According to the present invention, since the external gear rolls in the internal gear due to the meshing of the internal gear and the external gear, the clutch of the clutch caused by slippage between the internal gear and the external gear is generated. Slip between the input shaft and the output shaft is avoided.

  According to a fourth aspect of the present invention, in the vehicle steering apparatus according to any one of the first to third aspects, the locking urging means is provided between the drive pin and a base end portion of each of the wedges. It is characterized by.

  According to this invention, since the biasing means for locking is provided between the drive pin and the base end portion of each wedge, there is a gap between the drive pin and the wedge when the drive pin rotates the pair of wedges. Even if it occurs, torque (reaction force) is generated without causing the drive pin to idle. Therefore, the gap between the drive focus wedge is not felt as play of the steering wheel, and the operation feeling of the steering wheel is good.

  A fifth aspect of the present invention is the vehicle steering apparatus according to any one of the first to fourth aspects, wherein the reverse biasing means biases the lock release pin in the reverse direction, and the reverse biasing means. And an electromagnetic solenoid for projecting the lock release pin against the urging force.

  According to the present invention, since the electromagnetic solenoid is energized in the steer-by-wire mode, the pair of lock release pins are attracted by the electromagnetic solenoid and protrude toward the tip of each wedge, and the pair of wedges are mutually connected. Is pushed in the direction of approaching to hold the unlocked state and idles, and the clutch is disengaged. On the other hand, when an abnormality occurs and the electromagnetic solenoid is not energized, the pair of lock release pins are retracted by the biasing force of the reverse biasing means and the pressure on the pair of wedges is released. The pair of wedges are urged away from each other, and the inner peripheral surface forming member locked by the wedge effect is driven to rotate by the drive pin, and the clutch is brought into a connected state.

  According to the vehicle steering apparatus of the first aspect, the drive pin interposed between the base end portions of the pair of wedges and protruding from the other end surface of the input shaft or the output shaft is separated from the pair of wedges. Against the biasing force of the locking biasing means provided to be able to advance and retreat from the other end surface of the input shaft or the output shaft to the tip of each wedge. And a pair of unlocking pins that release the lock by pressing the pair of wedges toward each other, so in the steer-by-wire mode, which is the normal use state, the unlocking pin of the clutch is the tip of each wedge The pair of wedges are pushed in the direction approaching each other against the biasing force of the locking biasing means to maintain the unlocked state, while if the unlocking pin moves backward during an abnormality, Energized means is held in the locked state can not be relatively rotated and a pair of wedge and the inner peripheral surface forming member and the outer peripheral surface forming member by the wedge effect biases the direction away a pair of wedges. Due to such a configuration, there is no need to manage the size of the two gaps as in the prior art, and a reliable locking can be ensured even if the accuracy is lower than in the prior art, and a highly safe vehicle steering device is provided. be able to.

  According to the vehicle steering apparatus of the second aspect, since the inner peripheral surface forming member and the outer peripheral surface forming member are the inner peripheral surface rotating body and the outer peripheral surface rotating body that do not have teeth, gear processing is not required. Only the manufacturing cost is cheap. Further, in the case of meshing contact between gears, accuracy is required so as not to be caught when disengagement, but accuracy is not required because of rolling contact. Furthermore, in the case of meshing contact, accuracy is required in this way, so the amount of eccentricity between the internal gear and the external gear is limited, but in the case of the inner peripheral surface rotating body and the outer peripheral surface rotating body, the accuracy is limited. Therefore, the amount of eccentricity is not limited, and the transmission torque can be increased by reducing the amount of eccentricity and by reducing the angle of the wedge, so that the degree of freedom in design is high.

  According to the vehicle steering apparatus of the third aspect, since the inner peripheral surface forming member and the outer peripheral surface forming member are the internal gear and the external gear having teeth, the inner peripheral surface forming member, the outer peripheral surface forming member, Mesh and contact, and no slippage occurs.

  According to the vehicle steering apparatus of the fourth aspect, since the locking urging means is provided between the drive pin and the base end portion of each wedge, when the drive pin rotationally drives the pair of wedges, Even if a gap is generated between the wedges, torque (reaction force) is generated without causing the drive pins to idle. For this reason, the gap between the drive pin and the wedge is not felt as play of the steering wheel, and the steering wheel operation feeling is good.

  According to the vehicle steering apparatus of the fifth aspect, since the electromagnetic solenoid is energized in the steer-by-wire mode, the pair of lock release pins are attracted by the electromagnetic solenoid and protrude toward the front ends of the respective wedges. Thus, the pair of wedges are pressed in directions approaching each other to hold the unlocked state and rotate idly, and the clutch is disengaged. On the other hand, when an abnormality occurs and the electromagnetic solenoid is not energized, the pair of lock release pins are retracted by the biasing force of the reverse biasing means and the pressure on the pair of wedges is released. The pair of wedges are urged away from each other, and the inner peripheral surface forming member locked by the wedge effect is driven to rotate by the drive pin, and the clutch is brought into a connected state. That is, when energization is stopped at the time of abnormality, the clutch is automatically connected and the direct connection mode is set, and safety is ensured.

Embodiments of a vehicle steering apparatus according to the present invention will be described below with reference to the drawings.
(A) Embodiment 1
First, the first embodiment will be described.

  1 and 2 are explanatory diagrams of operation, FIG. 3 is a schematic configuration diagram of a vehicle steering device, FIG. 4 is a sectional view of an electromagnetic clutch in a disconnected state, FIG. 5 is a sectional view of an electromagnetic clutch in a connected state, and FIG. The perspective view of a clutch and FIG. 7 are sectional drawings of the principal part.

  As shown in FIG. 3, the vehicle steering apparatus 1 detects a steering wheel 2 that is rotated by a driver, a steering shaft 2a coupled to the steering wheel 2, and a rotational operation amount of the steering shaft 2a. A steering angle sensor 3 as an operation amount detecting means for generating a steering angle signal a, a torque sensor 4 for detecting a rotational torque of the steering shaft 2a and generating a steering torque signal b, and a steering for applying a reaction force to the steering shaft 2a The reaction force mechanism 5, the steering actuator 6d that rotationally drives the pinion shaft 6a by the number of rotations corresponding to the steering angle signal a of the steering angle sensor 3, and the rotational motion of the pinion shaft 6a driven by the steering actuator 6d The reciprocating motion of the rack 6c is changed by the engagement between a pinion (not shown) provided on the pinion shaft and the rack 6c. A wheel angle conversion mechanism 6 as a steering mechanism for steering the wheel 10, and an electromagnetic clutch 8 as a clutch for mechanically connecting / disconnecting the steering shaft 2a and the pinion shaft 6a of the wheel angle conversion mechanism 6; The steering angle signal a and the steering torque signal b are input, and further signals such as the vehicle speed (V), yaw rate (ω), lateral acceleration (G), etc. are input as the in-vehicle LAN signal S, and the steering actuator 6d And a steer-by-wire control unit (SBW control unit) 9 for controlling the force mechanism 5 and the electromagnetic clutch 8. Reference numeral 11 denotes a battery.

  During normal driving, when the steering wheel 2 is rotated, the amount of rotation of the steering shaft 2 a is detected by the steering angle sensor 3, and the steer-by-wire control unit 9 is based on the steering angle signal a of the steering angle sensor 3. Outputs a control signal A to the steering actuator 6d. As a result, the steering actuator 6d is driven in accordance with the rotational operation amount of the steering wheel 2, and the rotational motion of the steering actuator 6d is transmitted to the pinion shaft 6a of the wheel angle conversion mechanism 6. In the wheel angle conversion mechanism 6, the pinion shaft 6a is transmitted. Is converted into a reciprocating motion of the rack 6c, and the wheel 10 is steered by the reciprocating motion of the rack 6c. Thus, in the steer-by-wire mode in which the rotation of the steering wheel 2 is converted into the rotation of the steering actuator 6d, the torque sensor 4 detects the steering torque, and the steer-by-wire control unit 9 based on the steering torque signal b of the torque sensor 4 Outputs a control signal B to the steering reaction force mechanism 5 so that the steering wheel 2 can be operated with an appropriate torque.

  On the other hand, when it is determined that the steer-by-wire mode cannot be normally executed due to an abnormality in the vehicle electrical system or the steer-by-wire system, the steer-by-wire control unit 9 issues a control signal C to the electromagnetic clutch 8 and the electromagnetic clutch 8 Switch from the disconnected state to the connected state to enter the direct connection mode. Thereby, the steering shaft 2a is mechanically connected to the pinion shaft 6a of the wheel angle conversion mechanism 6 via the electromagnetic clutch 8 in the connected state.

  Next, the configuration of the electromagnetic clutch 8 will be described. As shown in FIG. 4, a cylindrical housing 11 is provided. A connection shaft 13 as an input shaft is rotatably provided on the upper portion of the housing 11 via a bearing 12, and an output as an output shaft is provided at the lower portion. A pulley 15 is rotatably provided via a bearing 14. The upper connection shaft 13 is connected to the steering shaft 2 a shown in FIG. 3, while the lower output pulley 15 is connected to the pinion shaft 6 a of the wheel angle conversion mechanism 6. The connection shaft 13 is configured by connecting a lower shaft end member 13c having a centering shaft portion 13b and an upper shaft end member 13d via a bolt 13e. The output pulley 15 and the pinion shaft 6a are connected via a cable 7 wound between the output pulley 15 and the pulley 6b of the pinion shaft 6a.

  As shown in FIG. 4, a connecting mechanism for connecting these two shafts so that the end surfaces thereof face each other in the vertical direction and the output pulley 15 so as to integrally rotate or separate so as not to transmit the rotation. 24 is provided. As shown in FIGS. 1, 2, and 7, the coupling mechanism 24 includes an inner peripheral surface rotating body 17 as an inner peripheral surface forming member coupled to the upper end surface of the lower output pulley 15, and the inner peripheral surface. The outer peripheral surface rotating body 18 as an outer peripheral surface forming member having an outer peripheral surface 18 a rolling on the inner peripheral surface 17 a of the rotating body 17, a pair of wedges 20, and an upper connecting shaft 13 are formed to project downward in the axial direction. A drive pin 23 interposed between the base end portions of the pair of wedges 20, and a lock provided between the drive pin 23 and the base end portions of the respective wedges to urge the pair of wedges 20 in a direction away from each other. A leaf spring 21 as a biasing means, and a pair of wedges 20 are provided against each other against the biasing force of the leaf spring 21 provided so as to be able to advance and retreat from the end surface of the connection shaft 13 to the tip of each wedge 20. A pair of locks pressed in the direction approaching And a release pin 28 Metropolitan.

  As shown in FIGS. 1, 4, and 7, a circular recess 17 c is formed in the inner peripheral surface rotating body 17 by half-cutting the inside of the disk with a press, and the inner peripheral surface rotating body 17 includes a plurality of bolts 26. To the upper end surface of the lower output pulley 15. A cylindrical portion 17b is integrally formed on the inner peripheral surface rotating body 17 so as to rise axially upward from the center portion of the circular concave portion 17c, and a ring is formed between the cylindrical portion 17b and the inner peripheral surface 17a of the circular concave portion 17c. The outer peripheral surface rotating body 18 is loosely fitted into the groove portion. The outer peripheral dimension of the outer peripheral surface rotating body 18 is shorter than the inner peripheral dimension of the inner peripheral surface rotating body 17, and the outer peripheral surface 18 a of the outer peripheral surface rotating body 18 is included in the inner peripheral surface 17 a of the inner peripheral surface rotating body 17. There is rolling contact. Fine irregularities are formed on the inner peripheral surface 17a and the outer peripheral surface 18a by knurling or the like.

  As shown in FIGS. 1, 4 and 7, a circular hole is formed in the central portion of the outer peripheral surface rotating body 18, and a metal metal is attached to the circular hole for smooth sliding. A dynamic inner peripheral surface 18b is configured. An annular space 22 is formed between the sliding inner peripheral surface 18 b and the cylindrical portion 17 b of the inner peripheral surface rotating body 17, and a pair of wedges 20 are accommodated in the annular space 22. Each of the wedges 20 has a substantially arc shape, has a proximal end portion with a large radial width dimension and a smaller distal end portion, and is arranged so that the proximal end portions face each other.

  As shown in FIG. 1, FIG. 4, and FIG. 7, the centering shaft portion 13b is formed so as to protrude from the axial center position of the lower end surface of the connection shaft 13, as described above. The inner circumferential surface rotating body 17 is rotatably inserted into the cylindrical portion 17b. A drive pin 23 is provided at an eccentric position on the lower end surface of the connection shaft 13 so as to protrude downward. That is, a recess 13f is formed in the lower shaft end member 13c, and the drive pin 23 is fixed by caulking the upper end of the drive pin 23 passing through the shaft end member 13c toward the recess 13f. . The distal end portion of the drive pin 23 is interposed between the base end portions of the pair of wedges 20, and the pair of wedges 20 are mutually connected between the drive pin 23 and the base end portions of the respective wedges 20. Leaf springs 21 are provided as locking urging means for urging in a direction away from each other. Each of the leaf springs 21 is formed in a “<” shape in cross section.

  Further, at two positions which are the lower end of the upper connecting shaft 13 and are separated from each other by the same angle in the opposite direction to the drive pin 23 in the circumferential direction, the lower end surface of the connecting shaft 13 extends downward in the axial direction. A pair of lock release pins 28 are provided so as to be able to advance and retreat. The pair of lock release pins 28 are for pressing the pair of wedges 20 in a direction approaching each other against the urging force of the leaf spring 21.

  A mechanism for moving the pair of lock release pins 28 forward and backward from the end face of the connection shaft 13 will be described. As shown in FIG. 4, an accommodation space is formed by a recess 13f formed in the lower shaft end member 13c constituting the connection shaft 13 and a recess 13h formed in the upper shaft end member 13d. Accommodates an electromagnetic solenoid 16 for advancing and retracting the pair of lock release pins 28 downward. A substantially circular disk 19 perpendicular to the movable iron core 16a is coupled to the upper end of the movable iron core 16a constituting the electromagnetic solenoid 16, and the disk 19 is located at an eccentric position as shown in FIG. Holes are formed at two locations, and the upper ends of the lock release pins 28 are inserted into the holes, and the lengths of both holes can be adjusted by two nuts 27. A small-diameter portion 28b is formed at the tip of the unlocking pin 28 via a tapered portion 28a, while a tapered hole 13g is formed in the shaft end member 13c. When the unlocking pin 28 protrudes, the tapered portion 28a becomes a tapered hole. Fits 13g with no gap. That is, there is a gap between the unlocking pin 28 and the tapered hole 13g before the unlocking pin 28 arrives at the lowermost position, but there is play, but when the unlocking pin 28 arrives at the lowermost position, the tapered portion 28a becomes the tapered hole 13g. Therefore, the pair of wedges 20 are pressed in a direction approaching each other. The lower end of the movable iron core 16a is inserted into a hole 13a formed in the centering shaft portion 13b. When the movable iron core 16a is not sucked downward, the movable iron core 16a is moved upward. A reverse spring 25 is provided as a reverse biasing means for biasing toward the rear.

  Next, the relationship between the drive pin 23 and the pair of lock release pins 28 will be described. The drive pin 23 protruding downward from the connection shaft 13 is interposed between the base end portions of the pair of wedges 20 in the annular space 22, so that the distal ends of the pair of wedges 20 and the pair of locks The relative position in the circumferential direction with respect to the release pin 28 is fixed. Therefore, even if the upper connection shaft 13 rotates, the position of the pair of lock release pins 28 protruding from the connection shaft 13 is It is always the position of the tip of the pair of wedges 20.

  Next, the operation of the vehicle steering apparatus will be described.

  According to the present invention, in the steer-by-wire mode, which is a normal use state, the rotational speed of the steering wheel 2 is detected, the steering actuator 6d is driven by an amount corresponding to the detected value by the detection, and the steering actuator 6d is driven. As a result, the rack 6c reciprocates in the left-right direction of the vehicle body, and the wheels are steered by the rack 6c. At this time, as shown in FIGS. 1 and 4, the lock release pin 28 of the electromagnetic clutch 8 protrudes toward the tip of each wedge 20, so that the pair of wedges 20 resists the biasing force of the leaf spring 21. Thus, the pair of wedges 20 in the unlocked state are pressed by the directions approaching each other, and the pair of wedges 20 in the unlocked state are rotationally driven by the drive pins 23 to form the inner peripheral surface forming member 17 and the outer peripheral surface forming member 18. Idle between. Therefore, rotation is not transmitted from the connection shaft 13 provided with the drive pin 23 to the output pulley 15 provided with the inner peripheral surface forming member 17, and the electromagnetic clutch 8 is in a disconnected state.

  On the other hand, when the steer-by-wire mode cannot be normally executed due to an abnormality in the vehicle electrical system or the steer-by-wire system, and the steer-by-wire control unit 9 determines that the abnormality is present, the energization to the electromagnetic solenoid 16 is stopped. . Then, the suction force to the movable iron core 16a does not act, and the urging force of the retreating spring 25 acts on the movable iron core 16a, so that the lock release pin 28 moves backward in the axial direction together with the movable iron core 16a and the disc 19. Therefore, it becomes as shown in FIGS. When the lock release pin 28 is retracted, the leaf spring 21 biases the pair of wedges 20 away from each other, so that the pair of wedges 20, the inner peripheral surface forming member 17, and the outer peripheral surface forming member 18 are relatively rotated by the wedge effect. The locked inner peripheral surface forming member 17 is rotationally driven by the drive pin 23. Accordingly, the rotation is transmitted from the connection shaft 13 provided with the drive pin 23 to the output pulley 15 provided with the inner peripheral surface forming member 17, and the electromagnetic clutch 8 is brought into a connected state. Due to the connection of the electromagnetic clutch 8, the steering wheel 2 and the pinion shaft 6a are mechanically directly connected to enter the direct connection mode. In the direct connection mode, the pinion shaft 6a is directly driven to rotate from the steering wheel 2 without the steering actuator 6d. Then, the rotational motion of the pinion shaft 6a is converted into the reciprocating motion of the rack 6c, and the wheel 10 is steered.

  According to the present invention, since the inner peripheral surface rotating body 17 and the outer peripheral surface rotating body 18 are in rolling contact with each other and transmit the rotation at the contact portion, the manufacturing cost is reduced by the amount not requiring gear machining. Further, in the case of meshing contact between gears, accuracy is required so as not to be caught when the mesh is disengaged, but accuracy is not required because of rolling contact. Furthermore, in the case of meshing contact, since accuracy is required, the amount of eccentricity between the internal gear and the external gear is limited. However, in the case of the inner peripheral surface rotating body 17 and the outer peripheral surface rotating body 18, accuracy is required. Therefore, the amount of eccentricity is not limited, and the transmission torque can be increased by reducing the amount of eccentricity and decreasing the angle of the wedge 20, and the degree of freedom in design is high.

  According to the present invention, since the leaf spring 21 is provided between the drive pin 23 and the base end portion of each wedge 20, when the drive pin 23 rotationally drives the pair of wedges 20, the drive pin 23 and the wedge 20. Torque (reaction force) is generated without causing the drive pin 23 to idle by the gap even if a gap is generated between the two. Therefore, the gap between the drive pin 23 and the wedge 20 is not felt as play of the steering wheel. Instead, the drive pin 23 and the pair of wedges 20 rotate together, and the steering wheel 2 has an operation fee. Good ring.

According to the present invention, since the electromagnetic solenoid 16 is energized in the steer-by-wire mode, the pair of lock release pins 28 are attracted by the electromagnetic solenoid 16 and protrude toward the tip of each wedge 20. The wedges 20 are pressed in directions approaching each other so as to rotate while holding the unlocked state, and the electromagnetic clutch 8 is disengaged. On the other hand, when an abnormality occurs and the electromagnetic solenoid 16 is not energized, the pair of lock release pins 28 are retracted by the urging force of the retreating spring 25 and the pressure on the pair of wedges 20 is released. The pair of wedges 20 are urged away from each other, and the inner peripheral surface forming member 17 locked by the wedge effect is rotationally driven by the drive pin 23, and the electromagnetic clutch 8 is in the connected state.
(B) Embodiment 2
Next, a second embodiment will be described.

  Since this embodiment is obtained by changing a part of the first embodiment, description of the same portion is omitted and only different portions are described.

  FIG. 8 shows a drawing corresponding to FIG. 1B in the first embodiment. In the first embodiment, as shown in FIG. 1A, an inner peripheral surface rotating body 17 as an inner peripheral surface forming body and an outer peripheral surface rotating body 18 as an outer peripheral surface forming body are provided, and the inner peripheral surface rotating body 17 is provided. The inner peripheral surface 17a is configured such that the outer peripheral surface rotating body 18 rolls. However, in the second embodiment, as shown in FIG. 8, the internal gear 17p as the inner peripheral surface forming body and the outer peripheral surface forming body are used. The external gear 18p is provided so that the external gear 18p rolls inside the internal gear 17p while the internal teeth 17q of the internal gear 17p mesh with the external teeth 18q of the external gear 18p. . The number of teeth of the external teeth 18q is 1 or 2 less than the number of teeth of the internal teeth 17q.

  Since other constituent actions are the same as those of the first embodiment, description thereof is omitted.

  According to the present invention, since the external gear 18p rolls inside the internal gear 17p due to the meshing of the internal gear 17p and the external gear 18p, it slips between the internal gear 17p and the external gear 18p. Slip between the connection shaft 13 of the electromagnetic clutch 8 and the output pulley 15 due to the occurrence of this is avoided.

  In the first and second embodiments, the inner peripheral surface rotating body or the internal gear is coupled to the end surface of the output shaft that constitutes the clutch, and the drive pin is formed to protrude from the end surface of the input shaft. May be reversed. Further, although the rotational motion of the steering actuator is converted into the reciprocating motion of the rack by the steering mechanism, a configuration may be adopted in which the rotational motion of the steering actuator is directly converted into the reciprocating motion of the rack without going through the steering mechanism. Furthermore, although the urging means for locking is provided between the drive pin and the base end portion of each wedge, it may be provided between each wedge without interposing the drive pin. Furthermore, although the electromagnetic solenoid that stops energization at the time of abnormality and the reverse spring are used to drive the lock release pin, other configurations may be adopted.

It is related with the connection mechanism of a lock release state, (a) is sectional drawing, (b) is the AA arrow directional view of (a) (Embodiment 1). (A) is sectional drawing, (b) is a BB arrow line view of (a) (embodiment 1) concerning a connection mechanism in a locked state. 1 is a configuration diagram showing an overall configuration of a vehicle steering device (Embodiment 1). Sectional drawing of the electromagnetic clutch of a disengaged state (Embodiment 1). Sectional drawing of the electromagnetic clutch of a connection state (Embodiment 1). The perspective view of an electromagnetic clutch (Embodiment 1). It is related with the principal part of an electromagnetic clutch, (a) is front sectional drawing, (b) is a top view (Embodiment 1). The top view which shows the principal part of an electromagnetic clutch (Embodiment 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle steering device 2 ... Steering wheel 6 ... Wheel angle conversion mechanism (steering mechanism)
6a ... pinion shaft 6c ... rack 6d ... steering actuator 8 ... electromagnetic clutch (clutch)
10 ... Wheel 13 ... Connection shaft (input shaft)
15 ... Output pulley (output shaft)
16 ... Electromagnetic solenoid 17 ... Inner peripheral surface rotating body (inner peripheral surface forming member)
17a ... inner peripheral surface 17b ... cylindrical portion 17p ... internal gear (inner peripheral surface forming member)
17q ... inner teeth 18 ... outer peripheral surface rotating body (outer peripheral surface forming member)
18a ... outer peripheral surface 18b ... sliding inner peripheral surface (circular hole)
18p ... external gear (outer peripheral surface forming member)
18q ... external teeth 20 ... wedge 21 ... leaf spring (lock biasing means)
22 ... Annular space 23 ... Drive pin 25 ... Retraction spring (retraction biasing means)
28 ... Lock release pin

Claims (5)

A steering actuator that drives the amount corresponding to the detected value obtained by detecting the number of rotations of the steering wheel is provided. The steering actuator is connected to a rack that can reciprocate in the left-right direction of the vehicle body, and both ends of the rack are connected to wheels. On the other hand, a pinion shaft is connected to the steering wheel via a clutch that performs mechanical connection and disconnection, and a pinion provided on the pinion shaft is engaged with the rack,
The clutch includes an inner peripheral surface forming member coupled to one of the end surfaces of an input shaft connected to the steering wheel and an output shaft connected to the pinion shaft. An outer peripheral surface forming member having an outer peripheral surface rolling on the inner peripheral surface of the peripheral surface forming member, a cylindrical portion integrally provided at the central portion of the inner peripheral surface forming member, and a central portion of the outer peripheral surface forming member An annular space formed between the circular holes, a pair of wedges provided in the annular space with the wide base ends opposed to each other, and the base ends of the pair of wedges A drive pin interposed between the input shaft and the other end surface of the output shaft, a biasing means for locking to bias and lock the pair of wedges in a direction away from each other, and the input shaft or Front from the other end face of the output shaft A pair of lock release pins which are provided so as to be able to advance and retreat to the front ends of the respective wedges, and which release the lock by pressing the pair of wedges in a direction approaching each other against the urging force of the locking urging means; A vehicle steering apparatus characterized by the above. The vehicle steering apparatus according to claim 1,
Vehicle steering characterized in that the inner peripheral surface forming member and the outer peripheral surface forming member are an inner peripheral surface rotating body and an outer peripheral surface rotating body in which the outer peripheral surface is in rolling contact with the inner peripheral surface. apparatus. The vehicle steering apparatus according to claim 1,
The vehicle steering apparatus according to claim 1, wherein the inner peripheral surface forming member and the outer peripheral surface forming member are an internal gear and an external gear with which the outer peripheral surface is in meshing contact with the inner peripheral surface. In the vehicle steering device according to any one of claims 1 to 3,
The vehicle steering apparatus according to claim 1, wherein the locking urging means is provided between the drive pin and a base end portion of each of the wedges. In the vehicle steering device according to any one of claims 1 to 4,
A reverse biasing means for biasing the unlocking pin in a reverse direction; and an electromagnetic solenoid for projecting the unlocking pin against the biasing force of the reverse biasing means. A vehicle steering device.

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