JP2007269280A - Vehicular steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular steering device capable of mechanically and directly connecting a steering member and a steering mechanism when various kinds of fails are generated in a so-called steer-by-wire system steering device. <P>SOLUTION: The vehicular steering device is provided with a steering shaft 3 supported on a housing without being mechanically connected to the steering mechanism for varying a direction of a wheel; and a drive means for driving the steering mechanism according to steering of the steering member connected to the steering shaft 3. The steering device is provided with an expansion/contraction shaft 63 expandable/contractable in an axial direction and capable of transmitting rotation between the steering shaft 3 and the steering mechanism. When the drive means is not operated, the expansion/contraction shaft 63 is stretched and the steering shaft 3 and the steering mechanism are mechanically connected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a so-called steer-by-wire vehicle steering apparatus that can drive a steering mechanism in response to steering of a steering member without being mechanically coupled to a steering mechanism that changes the direction of a wheel.

  Steering of a vehicle is performed by operating a steering member (generally a rotating operation of a steering wheel) performed by a driver inside a passenger compartment to steer a steering wheel (generally a front wheel). It is transmitted to the steering mechanism arranged outside the room.

  As such a vehicle steering device, in recent years, a steering mechanism including a steering member inside a vehicle compartment is mechanically separated from a steering mechanism outside the vehicle compartment, and a steering actuator is attached to a part of the steering mechanism. The steering actuator is operated based on the detection result of the operation direction and the operation amount of the steering member, and the steering mechanism is configured to apply the steering force to the steering mechanism to perform the steering according to the operation of the steering member. Devices, so-called steer-by-wire steering devices have been proposed.

  The steer-by-wire steering device can freely change the correspondence between the operation amount of the steering member and the operation amount of the steering mechanism by the operation of the steering actuator without being subjected to mechanical restrictions, and the vehicle speed can be increased or decreased. In addition, there is an advantage that it is possible to flexibly cope with the change control of the steering characteristics in accordance with the traveling state, such as the degree of turning and the presence or absence of acceleration / deceleration. In general, an electric motor is used as the steering actuator in consideration of the ease of changing the steering characteristics.

  On the other hand, in a steer-by-wire steering device, a steering actuator, various sensors for detecting the traveling state of the vehicle including the operation direction and operation amount of the steering member, and the steering actuator based on the detection results of these sensors are provided. A fail-safe measure for the steering control unit to be controlled is important from the viewpoint of safety. As a fail-safe measure, a steering system, a sensor, and a steering control unit are often used as a double system.

On the other hand, an electromagnetic clutch is interposed between the input side member that rotates in response to the operation of the steering member and the output side member that rotates in accordance with the operation of the steering mechanism. The side member is engaged so that the operation force of the steering member can be mechanically transmitted to the steering mechanism so that manual steering can be performed (see Patent Documents 1 and 2). In Patent Document 3, a steering apparatus for a vehicle that manually engages an input-side member and an output-side member without using an electromagnetic clutch and mechanically transmits the operation force of the steering member to the steering mechanism. Is disclosed.
JP 2001-026277 A JP 2001-260908 A JP 2001-341655 A

  However, when using an electromagnetic clutch as in Patent Documents 1 and 2, it is necessary to configure an operation circuit and a control unit so as to connect or disconnect the input side member and the output side member. It is difficult to greatly separate the member. Therefore, although the physical restrictions on the space in the steering device design are relaxed compared with the manual steering, there is a problem that it is difficult to ensure a sufficient degree of freedom.

  Further, in Patent Document 3, the steering angle of the steering member and the rotation angle on the steering device side are different and can be connected only at a predetermined angle. There was a problem that it was not possible.

  The present invention has been made in view of such circumstances, and in a so-called steer-by-wire type steering apparatus, when various types of failures occur, the operation of the input side member and the steering mechanism that rotate according to the operation of the steering member An object of the present invention is to provide a vehicle steering apparatus capable of directly connecting an output side member that rotates in conjunction with the vehicle.

  In order to achieve the above object, a vehicle steering apparatus according to a first aspect of the present invention includes a steering shaft that is supported by a housing without being mechanically connected to a steering mechanism that changes the direction of wheels, and the steering shaft. In a vehicle steering apparatus including a driving unit that drives the steering mechanism in accordance with steering of a connected steering member, the vehicle can extend and contract in the axial direction between the steering shaft and the steering mechanism. A telescopic shaft capable of transmitting rotation, and when the driving means is inactive, the telescopic shaft is extended to mechanically connect the steering shaft and the steering mechanism. Features.

  The vehicle steering apparatus according to a second aspect of the present invention is the vehicle steering apparatus according to the first aspect, wherein the telescopic shaft has a clutch mechanism that has one end connected to the steering mechanism and the other end connected to the steering shaft. An internal pressure that generates an internal pressure that pushes an engagement surface with the steering shaft of the clutch mechanism at the other end inside the expansion / contraction portion, and is capable of expanding and contracting and sealing the inside. The generator is provided between the engagement surface and the steering mechanism.

  According to a third aspect of the present invention, there is provided the vehicle steering apparatus according to the first aspect, wherein the telescopic shaft has one end connected to the steering mechanism and the other end connected to the steering shaft, and the other end. And an internal pressure generating section that generates an internal pressure that pushes up an engagement surface of the clutch mechanism with the steering shaft in the steering shaft direction.

  According to a fourth aspect of the present invention, in the vehicle steering apparatus according to the second or third aspect, the clutch mechanism has a taper on the engagement surface.

  According to a fifth aspect of the present invention, there is provided the vehicle steering apparatus according to any one of the second to fourth aspects, wherein spline teeth are formed on the engagement surface.

  In the first invention, in a so-called steer-by-wire vehicle steering apparatus in which the steering mechanism and the steering member are not mechanically connected, the steering mechanism can be extended and contracted in the axial length direction between the steering shaft and the steering mechanism. Yes, it has a telescopic shaft that can transmit rotation. When the driving means for driving the steering mechanism does not operate normally, the telescopic shaft extends and the steering shaft and the steering mechanism are mechanically connected. By mechanically connecting the steering shaft and the steering mechanism via the telescopic shaft, the operation of the steering member can be directly transmitted to the steering mechanism, and even if the drive means does not operate, it is safe It is possible to steer the vehicle.

  In the second invention, one end of the telescopic shaft is connected to the steering mechanism, and the other end has a clutch mechanism that can be connected to and disconnected from the steering shaft. Also, an expansion / contraction part that is extendable and sealed inside, and an internal pressure generation that generates an internal pressure that pushes the engagement surface with the steering shaft of the clutch mechanism at the other end inside the expansion / contraction part toward the steering axis. Is provided between the engagement surface and the steering mechanism. As a result, when the internal pressure is generated, the gas filled inside the expansion / contraction part expands, the engagement surface with the steering shaft of the clutch mechanism is pushed upward, and the steering shaft and the steering mechanism And are mechanically connected. Therefore, the operation of the steering member can be directly transmitted to the steering mechanism, and the vehicle can be safely steered even when the driving means does not operate.

  In the third invention, one end of the telescopic shaft is connected to the steering mechanism, and the other end is steered on the engagement surface between the other end of the clutch mechanism that can be connected to the steering shaft and the other end of the clutch mechanism. And an internal pressure generating section that generates an internal pressure that is pushed up in the axial direction. As a result, when the internal pressure is generated, the engagement surface of the clutch mechanism with the steering shaft is pushed upward, and the steering shaft and the steering mechanism are mechanically connected. Therefore, the operation of the steering member can be directly transmitted to the steering mechanism, and the vehicle can be safely steered even when the driving means does not operate.

  In the fourth invention, the clutch mechanism has a tapered engagement surface. As a result, a stronger engagement can be obtained in the clutch mechanism, and the vehicle can be steered more safely even when the drive means does not operate.

  In the fifth invention, spline teeth are formed on the engagement surface. Thereby, the engagement of the spline teeth makes it possible to obtain a stronger engagement in the clutch mechanism, and the vehicle can be steered more safely even when the drive means does not operate.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a configuration of a main part of a vehicle steering apparatus according to Embodiment 1 of the present invention. A vehicle steering apparatus according to Embodiment 1 includes a steering mechanism 1 for causing a pair of steering wheels A, A arranged on the left and right of a vehicle body (not shown) to perform a steering operation, and a machine from the steering mechanism 1. A steering shaft 3 that is rotatably separated and supported by a stationary member such as the shaft housing 2, a steering wheel 4 that is a steering member connected to the upper end of the steering shaft 3, and the steering wheel 4. Accordingly, the driving means 5 for driving the steering mechanism 1 and the connecting means 6 for connecting the lower end of the steering shaft 3 to the steering mechanism 1 when the steering mechanism 1 cannot be driven due to a failure of the driving means 5. And.

  The shaft housing 2 that supports the steering shaft 3 is provided with a reaction force actuator 7 that applies a reaction force opposite to the steering direction to the steered wheels 4. The reaction force actuator 7 is driven in both forward and reverse directions by energization from the drive circuit 70 according to the operation command signal given from the drive means 5, and applies a force (reaction force) in the direction opposite to the steering direction of the steered wheels 4. Make an action.

  Therefore, it is necessary to apply a steering torque against the reaction force generated by the reaction force actuator 7 to steer the steered wheels 4. The torque sensor 8 that detects the steering torque, the steering amount of the steered wheels 4, and the steering direction For example, a rotary encoder 9 is attached to the shaft housing 2, and the results detected by the torque sensor 8 and the rotary encoder 9 are given to the drive means 5 via the interface circuit 10.

  As is well known, the steering mechanism 1 connects both ends of a steering shaft 11 that extends in the left-right direction of the vehicle body and moves in the axial length direction, and knuckle arms 12 and 12 that support the wheels A and A. The knuckle arms 12 and 12 are pushed and pulled by the movement of the steering shaft 11 in both directions, and the wheels A and A are steered left and right. This steering is coaxial with the middle portion of the steering shaft 11. The rotation of the brushless type steering motor 51 configured as described above is converted into the movement of the steering shaft 11 by an appropriate motion conversion mechanism.

  The steering shaft 11 includes a spiral groove on one end side in the axial length direction and a rack tooth on the other end side. The steering shaft 11 is not rotatable in the shaft housing 13 and is supported so as to be movable in the axial length direction. Yes. The shaft housing 13 has a pinion meshing with the rack teeth at the lower end, and a pinion shaft 16 to which the transmission shaft 15 is connected to the upper end via the joint 14 is rotatably supported, and the drive means 5 fails. The steering shaft 11 is moved by rotating the pinion shaft 16. The shaft housing 13 is provided with a sensor for detecting the amount and direction of rotation of the pinion shaft 16, for example, a rotary encoder 20. The result detected by the rotary encoder 20 is steered by the drive means 5 via the interface circuit 10. It is given to the control unit 52.

  The steering motor 51 is supported so as to be rotatable between a cylindrical stator fixed in a shaft housing 13 that supports the steering shaft 11, and an inner peripheral surface of the stator and an outer peripheral surface of the steering shaft 11. And a cylindrical rotor having a plurality of permanent magnets spaced apart from each other in the circumferential direction. A transmission ring that engages with a spiral groove provided on the steering shaft 11 is connected to the rotor, and the rotation of the steering motor 51 is transmitted to the steering shaft 11 through the transmission ring, and the steering shaft 11 is configured to move in the axial direction.

  The drive means 5 includes a steering motor 51 and a steering control unit 52 using a microprocessor. The steering motor 51 is rotated by energization from the drive circuit 50 given from the steering control unit 52, and the rotation of the steering motor 51 is converted into sliding in the axial direction of the steering shaft 11. Steering (steering wheels A and steering) according to the rotation of 51 is performed. The steering control unit 52 starts an operation in response to an ON operation of a key switch for starting the engine.

  FIG. 2 is a partially enlarged cross-sectional view of the connecting means 6 of the vehicle steering apparatus according to Embodiment 1 of the present invention on a plane orthogonal to the central axis of the steering shaft 3. As shown in FIG. 2A, the connecting means 6 includes first and second clutch plates 61 and 62 provided at the lower end portion of the steering shaft 3 and the upper end portion of the transmission shaft 15, respectively. The clutch plate 62 is provided with a telescopic shaft 63 that can move in the axial direction and can be rotatably held.

  The telescopic shaft 63 includes an inner cylinder 631 fixed to a support plate 64 fixed to the transmission shaft 15, and an outer cylinder 632 fitted on the inner cylinder 631. An O-ring 633 having a plurality of protruding portions on the inner peripheral side is inserted between the inner cylinder 631 and the outer cylinder 632, and the axial direction in which the O-ring 633 can be engaged with the outer periphery of the inner cylinder 631. The guide groove 634 is formed. As a result, the telescopic shaft 63 can slide in the axial direction and can rotate integrally in the circumferential direction. In addition, it is not limited to what has an O-ring, The structure by which a serration, a spline, etc. are formed in the axial direction at the outer periphery of the inner cylinder 631 may be sufficient.

  Between the second clutch plate 62 and the support plate 64, a synthetic resin bellows (expandable portion) 65 is provided. The internal space 66 covered with the bellows 65 is preferably airtight. An ignition device (internal pressure generating portion) 67 is provided on the surface of the support plate 64 in the internal space 66 covered with the bellows 65. The ignition device 67 includes an ignition circuit 671 and a glaze 672. When a spark is generated in the ignition circuit 671, the glaze 672 explodes, and the gas in the internal space 66 covered with the bellows 65 rapidly expands. To do.

  In addition, by providing the bellows 65 in a bellows shape, it is possible to absorb a twisting force applied when the steering shaft 3 rotates in a state where the first clutch plate 61 and the second clutch plate 62 are connected. Further, by making the bellows 65 made of composite synthetic resin, it can have high resistance against torsional tension. For example, the bellows 65 extends in a state where the first clutch plate 61 and the second clutch plate 62 are connected. Even when possible, it is possible to ensure the rigidity during steering. Therefore, it is possible to move more safely to a repairable facility.

  FIG. 3 is a diagram illustrating an example of the configuration of the ignition circuit 671 that operates the ignition device 67. In the example of FIG. 3, the ignition circuit 671 that operates the ignition device 67 is a charge pump circuit. By starting the oscillation circuit 673, the voltage V1 of the battery 674 is boosted and the high voltage V2 is supplied to the ignition unit 675. . The ignition part 675 is, for example, electrodes facing each other, and a discharge is generated due to a large potential difference between both electrodes, and a spark is generated. The ignition circuit 671 is not limited to the charge pump circuit, and for example, a DC-DC converter may be used.

  In the vehicle steering apparatus having the above-described configuration, when the driving means 5 such as the steering control unit 52 and the steering motor 51 are normal, the steering control unit 52 is operated according to the steering of the steering wheel 4. 51 is driven and the steering motor 51 drives the steering mechanism 1 to cause the steering wheels A and A to perform a steering operation.

  Steering torque against the reaction force generated by the reaction force actuator 7 is applied to the steering wheel 4. The steering torque is detected by the torque sensor 8, the steering amount of the steering wheel 4 is detected including the steering direction by the rotary encoder 9, and these detection results are given to the steering control unit 52.

  When an abnormality occurs in the driving means 5 such as the steering control unit 52 and the steering motor 51 and the steering mechanism 1 cannot be driven, the ignition device 67 activates the oscillation circuit 673 and the ignition unit 675. A spark is generated. Due to the occurrence of the spark, the glaze 672 disposed in the internal space 66 covered with the bellows 65 explodes, and the gas in the internal space 66 covered with the bellows 65 rapidly expands.

  The outer cylinder 632 fitted to the inner cylinder 631 is pushed upward by the expanded gas, and the second clutch plate 62 provided at the upper end of the transmission shaft 15 as shown in FIG. The first clutch plate 62 provided at the lower end of the steering shaft 3 is contacted and connected. When the first and second clutch plates are connected, the steering shaft 3 and the transmission shaft 15 are mechanically connected, and the rotation of the steering shaft 3 can be mechanically transmitted to the steering mechanism 1.

  As described above, according to the first embodiment, the telescopic shaft 63 is extended by the pressure of the glaze 672 due to the explosion, and the steering shaft 3 and the transmission shaft 15 to the steering mechanism 1 are mechanically connected to each other. The operation of the wheel 4 can be directly transmitted to the steering mechanism 1. Therefore, even when the driving unit 5 does not operate due to a failure or the like, the vehicle can be safely steered.

(Embodiment 2)
Hereinafter, a vehicle steering apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings. Since the configuration of the vehicle steering apparatus according to the second embodiment of the present invention is the same as that of the first embodiment, detailed description thereof is omitted by attaching the same reference numerals. The second embodiment is characterized in that the ignition device (internal pressure generating unit) 67 is provided inside the telescopic shaft 63.

  FIG. 4 is a partially enlarged cross-sectional view of the connecting means 6 of the vehicle steering apparatus according to Embodiment 2 of the present invention on a plane orthogonal to the central axis of the steering shaft 3. As shown in FIG. 4A, the connecting means 6 includes first and second clutch plates 61 and 62 provided at the lower end portion of the steering shaft 3 and the upper end portion of the transmission shaft 15, respectively. The clutch plate 62 is provided with a telescopic shaft 63 that can move in the axial direction and can be rotatably held.

  The telescopic shaft 63 includes an inner cylinder 631 fixed to a support plate 64 fixed to the transmission shaft 15, and an outer cylinder 632 fitted on the inner cylinder 631. Between the inner cylinder 631 and the outer cylinder 632, a first O-ring 635 and a second O-ring 636 having a plurality of projecting portions on the inner peripheral side are inserted separately in the axial length direction, A guide groove 634 in the axial length direction that can be engaged with the first O-ring 635 and the second O-ring 636 is formed on the outer periphery of the inner cylinder 631. As a result, the telescopic shaft 63 can slide in the axial direction and can rotate integrally in the circumferential direction. In addition, it is not limited to what has an O-ring, The structure by which a serration, a spline, etc. are formed in the axial direction at the outer periphery of the inner cylinder 631 may be sufficient.

  In the second embodiment, the first O-ring 635 prevents the explosive pressure caused by the glaze 672 of the ignition device 67 described later from escaping into the upper space, and the first clutch without reducing the expansion / contraction speed of the expansion / contraction shaft 63. The plate 61 and the second clutch plate 62 can be connected. In addition, the second O-ring 636 can prevent the increase in internal pressure due to the explosion of the glaze 672 from being saturated and the internal pressure from decreasing.

  A plurality of guide portions 637 projecting toward the inner cylinder 631 are provided at the distal end portion of the outer cylinder 632. FIG. 5 is a VV cross-sectional view of the telescopic shaft 63. As shown in FIG. 5, the guide portion 637 is formed to engage with the guide groove 634 of the inner cylinder 631. As a result, it is possible to secure rigidity against torsional force applied when the steering shaft 3 rotates while the first clutch plate 61 and the second clutch plate 62 are connected, and it is safer to repairable facilities. It becomes possible to move to.

  An ignition device (internal pressure generator) 67 is provided on the surface of the support plate 64 inside the inner cylinder 631 of the telescopic shaft 63. The ignition device 67 includes an ignition circuit 671 and a glaze 672. When a spark is generated in the ignition circuit 671, the glaze 672 explodes, and the gas in the space 68 inside the telescopic shaft 63 rapidly expands. In addition, since the structure of the ignition circuit 671 which operates the ignition device 67 is the same as that of Embodiment 1, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In the vehicle steering apparatus having the above-described configuration, when the driving means 5 such as the steering control unit 52 and the steering motor 51 are normal, the steering control unit 52 is operated according to the steering of the steering wheel 4. 51 is driven and the steering motor 51 drives the steering mechanism 1 to cause the steering wheels A and A to perform a steering operation.

  Steering torque against the reaction force generated by the reaction force actuator 7 is applied to the steering wheel 4. The steering torque is detected by the torque sensor 8, the steering amount of the steering wheel 4 is detected including the steering direction by the rotary encoder 9, and these detection results are given to the steering control unit 52.

  When an abnormality occurs in the driving means 5 such as the steering control unit 52 and the steering motor 51 and the steering mechanism 1 cannot be driven, the oscillation circuit 673 is activated to cause the ignition unit 675 to generate a spark. . Due to the occurrence of the spark, the glaze 672 disposed in the space 68 inside the telescopic shaft 63 explodes, and the gas in the space 68 inside the telescopic shaft 63 rapidly expands.

  Due to the expanded gas, the outer cylinder 632 fitted to the inner cylinder 631 is pushed upward, and as shown in FIG. 4B, the second clutch plate 62 provided at the upper end of the transmission shaft 15 is The first clutch plate 62 provided at the lower end portion of the steering shaft 3 is contacted and connected. When the first and second clutch plates are connected, the steering shaft 3 and the transmission shaft 15 are mechanically connected, and the rotation of the steering shaft 3 can be mechanically transmitted to the steering mechanism 1.

  As described above, according to the second embodiment, the telescopic shaft 63 is extended by the pressing of the glaze 672 due to the explosion, and the steering shaft 3 and the transmission shaft 15 to the steering mechanism 1 are mechanically connected to each other. The operation of the wheel 4 can be directly transmitted to the steering mechanism 1. Therefore, even when the driving unit 5 does not operate due to a failure or the like, the vehicle can be safely steered.

(Embodiment 3)
Hereinafter, a vehicle steering apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings. Since the configuration of the vehicle steering apparatus according to the third embodiment of the present invention is the same as that of the first embodiment, detailed description thereof is omitted by attaching the same reference numerals. The third embodiment is characterized in that a link mechanism that can be expanded and contracted in the axial length direction of the steering shaft 3 is provided instead of the expansion and contraction shaft 63 that is expanded by the ignition device (internal pressure generating portion) 67.

  FIG. 6 is a partially enlarged cross-sectional view of the connecting means 6 of the vehicle steering apparatus according to Embodiment 3 of the present invention on a plane orthogonal to the central axis of the steering shaft 3. As shown in FIG. 6A, the connecting means 6 includes first and second clutch plates 61 and 62 provided at the lower end portion of the steering shaft 3 and the upper end portion of the transmission shaft 15, respectively. Between the clutch plate 62 and the support plate 64 of the transmission shaft 15, there is provided a link mechanism 70 that can expand and contract in the axial direction of the steering shaft 3.

  The link mechanism 70 includes a support member 701 fixed to a support plate 64 fixed to the transmission shaft 15 and a support member 702 fixed to the back surface of the second clutch plate 62. Two link members 703 and 704 that are rotatable are connected to the support members 701 and 702, respectively, and a link member 703 that is connected to the support member 701 and a link member 704 that is connected to the support member 702. Are coupled so as to be rotatable in substantially the same direction as the direction in which the support members 701 and 702 can rotate.

  Between the second clutch plate 62 and the support plate 64, a synthetic resin bellows (expandable portion) 65 is provided. The internal space 66 covered with the bellows 65 is preferably airtight. An ignition device (internal pressure generating portion) 67 is provided on the surface of the support plate 64 in the internal space 66 covered with the bellows 65. The ignition device 67 includes an ignition circuit 671 and a glaze 672. When a spark is generated in the ignition circuit 671, the glaze 672 explodes, and the gas in the internal space 66 covered with the bellows 65 rapidly expands. To do. In addition, since the structure of the ignition circuit 671 which operates the ignition device 67 is the same as that of Embodiment 1, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In the vehicle steering apparatus having the above-described configuration, when the driving means 5 such as the steering control unit 52 and the steering motor 51 are normal, the steering control unit 52 is operated according to the steering of the steering wheel 4. 51 is driven and the steering motor 51 drives the steering mechanism 1 to cause the steering wheels A and A to perform a steering operation.

  Steering torque against the reaction force generated by the reaction force actuator 7 is applied to the steering wheel 4. The steering torque is detected by the torque sensor 8, the steering amount of the steering wheel 4 is detected including the steering direction by the rotary encoder 9, and these detection results are given to the steering control unit 52.

  When an abnormality occurs in the driving means 5 such as the steering control unit 52 and the steering motor 51 and the steering mechanism 1 cannot be driven, the oscillation circuit 673 is activated to cause the ignition unit 675 to generate a spark. . Due to the occurrence of the spark, the glaze 672 disposed in the internal space 66 covered with the bellows 65 explodes, and the gas in the internal space 66 covered with the bellows 65 rapidly expands.

  Due to the expanded gas, the outer cylinder 632 fitted to the inner cylinder 631 is pushed upward, the link mechanism 70 extends as shown in FIG. 6B, and the first is provided at the upper end of the transmission shaft 15. The second clutch plate 62 is connected in contact with the first clutch plate 62 provided at the lower end of the steering shaft 3. When the first and second clutch plates are connected, the steering shaft 3 and the transmission shaft 15 are mechanically connected, and the rotation of the steering shaft 3 can be mechanically transmitted to the steering mechanism 1.

  As described above, according to the third embodiment, the link mechanism 70 is extended by the pressure of the glaze 672 due to the explosion, and the steering shaft 3 and the transmission shaft 15 to the steering mechanism 1 are mechanically connected to each other. The operation of the wheel 4 can be directly transmitted to the steering mechanism 1. Therefore, even when the driving unit 5 does not operate due to a failure or the like, the vehicle can be safely steered.

(Embodiment 4)
Hereinafter, a vehicle steering apparatus according to Embodiment 4 of the present invention will be described with reference to the drawings. Since the configuration of the vehicle steering apparatus according to the fourth embodiment of the present invention is the same as that of the first embodiment, detailed description thereof will be omitted by attaching the same reference numerals. In the fourth embodiment, the engagement surface with the first clutch plate 61 is the upper surface of the cylindrical clutch member 81, and the clutch member 81 is driven in the direction of the steering shaft 3 by the ignition device (internal pressure generating portion) 67. It is characterized by a point that can be moved to.

  FIG. 7 is a partially enlarged cross-sectional view of the connecting means 6 of the vehicle steering apparatus according to Embodiment 4 of the present invention on a plane orthogonal to the central axis of the steering shaft 3. As shown in FIG. 7A, the connecting means 6 includes a first clutch plate 61 and a clutch member 81 provided at the lower end portion of the steering shaft 3 and the upper end portion of the transmission shaft 15, respectively. A rigid body combined with a cylindrical shape is formed and can be inserted into a support portion 82 fixed to the transmission shaft 15.

  Between the clutch member 81 and the side surface of the support portion 82, a piston ring (O-ring) 80 having an airtight seal and having a plurality of protrusions on the support portion 82 side is provided. A first guide groove 822 capable of guiding the protruding portion of the piston ring 80 in the axial length direction is provided on the inner peripheral surface. By doing so, the clutch member 81 can be easily inserted into the support portion 82, the structure is robust, and there is no leakage of the expanded gas, so that the clutch member 81 is securely connected to the first clutch plate 61. be able to.

  In the fourth embodiment, a plurality of guide portions 821 projecting toward the clutch member 81 are provided on the inner peripheral surface of the upper end portion of the support portion 82. The guide portion 821 is formed to engage with a second guide groove 811 provided on the outer peripheral surface of the clutch member 81. As a result, it is possible to secure rigidity against torsional force applied when the steering shaft 3 rotates in a state in which the first clutch plate 61 and the clutch member 81 are connected, and to move more safely to a repairable facility. It becomes possible.

  Between the clutch member 81 and the bottom surface of the support portion 82, an ignition device (internal pressure generating portion) 67 is provided on the bottom surface of the support portion 82. The ignition device 67 includes an ignition circuit 671 and a glaze 672, and when a spark is generated in the ignition circuit 671, the glaze 672 explodes, and the gas in the space 83 between the clutch member 81 and the bottom surface of the support portion 82. Expands rapidly. In addition, since the structure of the ignition circuit 671 which operates the ignition device 67 is the same as that of Embodiment 1, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In the vehicle steering apparatus having the above-described configuration, when the driving means 5 such as the steering control unit 52 and the steering motor 51 are normal, the steering control unit 52 is operated according to the steering of the steering wheel 4. 51 is driven and the steering motor 51 drives the steering mechanism 1 to cause the steering wheels A and A to perform a steering operation.

  Steering torque against the reaction force generated by the reaction force actuator 7 is applied to the steering wheel 4. The steering torque is detected by the torque sensor 8, the steering amount of the steering wheel 4 is detected including the steering direction by the rotary encoder 9, and these detection results are given to the steering control unit 52.

  When an abnormality occurs in the driving means 5 such as the steering control unit 52 and the steering motor 51 and the steering mechanism 1 cannot be driven, the oscillation circuit 673 is activated to cause the ignition unit 675 to generate a spark. . Due to the occurrence of the spark, the spark 672 explodes due to the occurrence of a spark in the ignition circuit 671, and the gas in the space 83 between the clutch member 81 and the bottom surface of the support portion 82 expands rapidly.

  The clutch member 81 is pushed upward by the expanded air, and the clutch member 81 provided at the upper end portion of the transmission shaft 15 is provided at the lower end portion of the steering shaft 3 as shown in FIG. 1 clutch plate 61 is contacted and connected. By connecting both, the steering shaft 3 and the transmission shaft 15 are mechanically connected, and the rotation of the steering shaft 3 can be mechanically transmitted to the steering mechanism 1.

  As described above, according to the fourth embodiment, the clutch member 81 is pushed upward by the pressure caused by the explosion of the glaze 672, and the steering shaft 3 and the transmission shaft 15 to the steering mechanism 1 are mechanically coupled. The operation of the steering wheel 4 can be directly transmitted to the steering mechanism 1. Therefore, even when the driving unit 5 does not operate due to a failure or the like, the vehicle can be safely steered.

(Embodiment 5)
Hereinafter, a vehicle steering apparatus according to Embodiment 5 of the present invention will be described with reference to the drawings. Since the configuration of the vehicle steering apparatus according to the fifth embodiment of the present invention is the same as that of the first embodiment, detailed description thereof will be omitted by attaching the same reference numerals. The fifth embodiment is characterized in that the time until the clutch mechanism is connected is shortened by devising the arrangement of the glaze in the fourth embodiment.

  FIG. 8 is a partially enlarged cross-sectional view of the connecting means 6 of the vehicle steering apparatus according to Embodiment 5 of the present invention on a plane orthogonal to the central axis of the steering shaft 3. As shown in FIG. 8A, the connecting means 6 includes a first clutch plate 61 and a clutch member 81 provided at the lower end portion of the steering shaft 3 and the upper end portion of the transmission shaft 15, respectively. A rigid body is formed by combining cylindrical shapes, and is inserted into a support portion 82 fixed to the transmission shaft 15.

  The clutch member 81 is firmly connected to the first clutch plate 61, and in order to ensure rigidity against torsional force applied when the steering shaft 3 rotates, a cylindrical portion 85 directed upward at the lower end is provided. A circumferential groove 811 is provided on the sliding surface with the support portion 82. When the clutch member 81 is pushed up to a predetermined position, that is, when the support portion 82 is pushed up to a position where it is connected to the first clutch member 61, the support portion 82 is a plate on the ring inserted into the groove 811 of the support portion 82. A spring 84 is provided. By inserting the leaf spring 84 into the groove of the support portion 82, the first clutch plate 61 and the clutch member 81 are more firmly connected to ensure rigidity against the torsional force applied when the steering shaft 3 rotates. Can be moved more safely to repairable facilities.

  In addition, a piston ring (O-ring) 80 having a plurality of protrusions is provided on the support portion 82 side between the clutch member 81 and the side surface of the support portion 82. A first guide groove 822 capable of guiding the protruding portion of the piston ring 80 in the axial length direction is provided on the inner peripheral surface of 82. By doing in this way, since the structure is robust and there is no leakage of the expanded gas, it can be reliably connected to the first clutch plate 61.

  Between the clutch member 81 and the bottom surface of the support portion 82, an ignition device (internal pressure generating portion) 67 is provided on the bottom surface of the support portion 82. The ignition device 67 includes an ignition circuit 671 and a glaze 672, and when a spark is generated in the ignition circuit 671, the glaze 672 explodes, and the gas in the space 83 between the clutch member 81 and the bottom surface of the support portion 82. Expands rapidly. A piston ring 80 having an airtight seal is provided between the clutch member 81 and the side surface of the support portion 82 to facilitate the insertion of the clutch member 81 into the support portion 82. Since the structure is robust and there is no leakage of the expanded gas, the first clutch plate 61 can be reliably connected. Moreover, since the structure of the ignition circuit 671 which operates the ignition device 67 is the same as that of Embodiment 1, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In the vehicle steering apparatus according to the fifth embodiment, the glaze 672 is disposed on the central axis of the steering shaft 3 so as to form a predetermined angle so as to increase toward the circumferential direction. By arranging the glaze 672 to have a conical depression as described above, a so-called Monroe effect is produced in which shock waves at the time of explosion are concentrated in the central axis direction, and the same amount of glaze 672 is used. Even if it exists, a bigger press can be provided to the clutch member 81. Therefore, it is possible to perform a reliable coupling operation even in the clutch member 81 which is a relatively heavy object.

  In the vehicle steering apparatus having the above-described configuration, when the driving means 5 such as the steering control unit 52 and the steering motor 51 are normal, the steering control unit 52 is operated according to the steering of the steering wheel 4. 51 is driven and the steering motor 51 drives the steering mechanism 1 to cause the steering wheels A and A to perform a steering operation.

  Steering torque against the reaction force generated by the reaction force actuator 7 is applied to the steering wheel 4. The steering torque is detected by the torque sensor 8, the steering amount of the steering wheel 4 is detected including the steering direction by the rotary encoder 9, and these detection results are given to the steering control unit 52.

  When an abnormality occurs in the driving means 5 such as the steering control unit 52 and the steering motor 51 and the steering mechanism 1 cannot be driven, the oscillation circuit 673 is activated to cause the ignition unit 675 to generate a spark. . Due to the occurrence of a spark, the glaze 672 explodes due to the occurrence of a spark in the ignition circuit 671, the gas in the space 83 between the clutch member 81 and the bottom surface of the support portion 82 expands rapidly, and the clutch member due to the Monroe effect. A strong pressure acts near the center of the bottom surface of 81.

  Due to such pressing, the clutch member 81 is pushed upward, and the clutch member 81 provided at the upper end portion of the transmission shaft 15 is provided at the lower end portion of the steering shaft 3 as shown in FIG. 1 clutch plate 61 is contacted and connected. In a state where both are connected, the leaf spring 84 of the support portion 82 is fitted into the groove of the cylindrical portion 85 of the clutch member 81, and the first clutch plate 61 and the clutch member 81 are more firmly connected.

  As described above, according to the fifth embodiment, by devising the arrangement of the glaze 672, the pressure caused by the explosion is amplified by the Monroe effect, so that the clutch member 81 and the first clutch plate 61 can be connected in a shorter time. Thus, the vehicle can be safely steered even when the driving means 5 does not operate due to a failure or the like. In particular, even a clutch member 81 that is relatively large and heavy as shown in FIG. 8 can be reliably connected.

  In the first to fifth embodiments described above, the engaging surfaces of the first clutch plate 61 and the second clutch plate 62 that are engaged with each other are not limited to flat plates. FIG. 9 is a partially enlarged cross-sectional view of the first clutch plate 61 and the second clutch plate 62 according to the first embodiment, illustrating a shape of an engaging surface that engages with each other, on a plane orthogonal to the central axis of the steering shaft 3. It is. In FIG. 9, the first embodiment is described as an example, but it goes without saying that the same applies to the second to fifth embodiments.

  As shown in FIG. 9A, protrusions 91 and 92 may be provided on the engaging surfaces of the first clutch plate 61 and the second clutch plate 62 that are engaged with each other. By providing the protrusions 91 and 92, the frictional force of the first clutch plate 61 and the second clutch plate 62 is increased, and both can be connected more firmly.

  Further, as shown in FIG. 9B, the engagement surfaces of the first clutch plate 61 and the second clutch plate 62 that engage with each other may be tapered. By providing the taper, the surface area of contact between the first clutch plate 61 and the second clutch plate 62 increases, and both can be more firmly connected.

  Further, as shown in FIG. 9 (c), not only are the engagement surfaces of the first clutch plate 61 and the second clutch plate 62 engaged with each other provided with a taper, but also the engagement surfaces are provided with spline teeth 93, They may be engaged with each other. By engaging the spline teeth 93 with each other, the first clutch plate 61 and the second clutch plate 62 can be more firmly connected.

  Note that the spline teeth 93 have a rounded shape on the tooth surface, thereby reducing the meshing of the spline teeth. That is, even if the rotational position of the steering shaft 3 immediately before the connection does not coincide with the rotational position of the steered shaft (transmission shaft 15), the second clutch plate 62 is pushed up by the pressure by the explosion pressure. When it is done, the spline teeth 93 can be reliably meshed. FIG. 9D is a perspective view showing an engagement surface shape of the second clutch plate 62, and FIG. 9E is a cross-sectional view of the second clutch plate 62 taken along line ee. ) Respectively show ff cross-sectional views of the first clutch plate 61. As shown in FIGS. 9D to 9F, the spline teeth 93 of the second clutch plate 62 have rounded tooth surfaces, and the rotational position of the steering shaft 3 and the steered shaft (transmission shaft 15). ) Even if the rotation position does not match, it autonomously rotates along the tooth surface to a position where both can mesh. Therefore, it is possible to reliably connect the steering shaft 3 without depending on the rotational position of the steering shaft 3, and it is possible to further improve the reliability when a failure occurs.

It is a schematic diagram which shows the principal part structure of the steering apparatus for vehicles which concerns on Embodiment 1 of this invention. It is a partial expanded sectional view in the surface orthogonal to the central axis of the steering shaft of the connection means of the steering apparatus for vehicles which concerns on Embodiment 1 of this invention. It is a figure which shows an example of a structure of the ignition circuit which operates a ignition device. It is a partial expanded sectional view in the surface orthogonal to the central axis of the steering shaft of the connection means of the steering apparatus for vehicles which concerns on Embodiment 2 of this invention. It is VV sectional drawing of an expansion-contraction axis. It is a partial expanded sectional view in the surface orthogonal to the central axis of the steering shaft of the connection means of the steering apparatus for vehicles which concerns on Embodiment 3 of this invention. It is a partial expanded sectional view in the surface orthogonal to the central axis of the steering shaft of the connection means of the steering apparatus for vehicles which concerns on Embodiment 4 of this invention. It is a partial expanded sectional view in the surface orthogonal to the central axis of the steering shaft of the connection means of the steering apparatus for vehicles which concerns on Embodiment 5 of this invention. FIG. 3 is a partial enlarged cross-sectional view of a first clutch plate and a second clutch plate according to the first embodiment on a plane orthogonal to the central axis of the steering shaft, illustrating the shape of the engaging surfaces that engage with each other.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Steering mechanism, 3 Steering shaft, 4 Steering wheel (steering member), 5 Drive means, 6 Connection means, 61 1st clutch board, 62 2nd clutch board, 63 Telescopic shaft, 65 Bellows (expandable part), 67 Ignition system (internal pressure generator), 93 spline teeth

Claims (5)

A steering shaft that is supported by the housing without being mechanically connected to a steering mechanism that changes the direction of the wheels, and a drive that drives the steering mechanism in response to steering of a steering member that is connected to the steering shaft A vehicle steering apparatus comprising:
Between the steering shaft and the steering mechanism, a telescopic shaft that can extend and contract in the axial direction and transmit rotation is provided.
The vehicle steering apparatus according to claim 1, wherein when the driving means is inactive, the telescopic shaft extends to mechanically connect the steering shaft and the steering mechanism. The telescopic shaft is
One end is connected to the steering mechanism, and the other end has a clutch mechanism that can be connected to and disconnected from the steering shaft.
An expansion / contraction portion that is extendable and sealed inside, and an internal pressure that generates an internal pressure that pushes the engagement surface of the clutch mechanism at the other end with the steering shaft toward the steering shaft. The generation part
The vehicle steering apparatus according to claim 1, wherein the vehicle steering apparatus is provided between the engagement surface and the steering mechanism. The telescopic shaft is
One end is connected to the steering mechanism, and the other end is a clutch mechanism that can be connected to and disconnected from the steering shaft.
The vehicle steering apparatus according to claim 1, further comprising: an internal pressure generation unit that generates an internal pressure that pushes an engagement surface of the clutch mechanism at the other end with the steering shaft in the steering shaft direction.   The vehicle steering apparatus according to claim 2 or 3, wherein the clutch mechanism has a taper on the engagement surface.   The vehicular steering apparatus according to any one of claims 2 to 4, wherein spline teeth are formed on the engagement surface.

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