JP2007270983A - Rotation transmission device for steer-by-wire system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light weight compact rotation transmission device of short axial direction length. <P>SOLUTION: The rotation transmission device constructs a major part of a failsafe mechanism of a steer-by-wire system. A cam surface 8 is provided on an outer circumference of a large diameter part 2 of a first shaft 1 connected to a steering wheel. A cylinder surface 7 is formed on an inner circumference of an outer ring 3 of an outside of the large diameter part 2 connected to the steering gear. A disk shape roller 11 built between the cylinder surface and the cam surface is stored in a radial direction groove 10 provided on a one surface of a magnetic body armature 9. A switch spring 13 is built between the armature and the large diameter part 2 and the armature 9 is elastically retained at a neutral position where engagement of the roller 11 is released. The rotor 18 is pressed in the outer ring 3, and an electromagnet is made opposite to the rotor. The armature 9 is attracted to the rotor by excitation of a magnetic coil 22a of the electromagnet, the roller is engaged with the cylinder surface and the cam surface by relative rotation of the armature and the first shaft and rotation of the first shaft is transmitted to the outer ring. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation transmission device for a steer-by-wire system in which a shaft coupled to a steering wheel and a shaft coupled to a steering gear are connected when a malfunction occurs in the steer-by-wire system, and the steering wheel can be directly steered. .

  In recent years, a steer-by-wire system has been developed in which a steering wheel, which is an automobile handle, and a steering gear, which is a steering wheel, are not mechanically coupled. This system generally switches a first shaft connected to a steering wheel and a second shaft connected to a steering gear to a connected state or a disconnected state by a clutch. There are merits such as enabling control and increasing the degree of freedom of the interior layout, and it is expected to enable more stable driving and improved drivability of the vehicle.

For example, as shown in FIG. 8, the steer-by-wire system includes a steering wheel H that is an automobile handle, a first shaft D <b> 1 coupled to the steering wheel H, a steering gear G, and a steering gear G. A second shaft D2 and a clutch C mounted between the first shaft D1 and the second shaft D2.
A first motor M1 that transmits a steering reaction force via a gear G1 is mounted on the first shaft D1, and a second motor M2 that transmits a steering force to the steering gear G via a gear G2 is mounted on the second shaft D2. It is installed.

  The controller (control device) P that controls the steer-by-wire system has various sensors such as a steering angle sensor S1 that detects the steering angle of the steering wheel H, and an abnormality detection sensor S2 that detects an abnormality of the system. Normally, the steering angle sensor S1 is installed on the first shaft D1, and the abnormality detection sensor S2 is installed (disconnected) on the first motor M1, the second motor M2, or both of them M1, M2.

  The controller P outputs a control signal to the first motor M1, the second motor M2, and the clutch C based on the signal related to the detected steering angle of the steering angle sensor S1 and the abnormality detection signal of the abnormality detection sensor S2. The clutch C is operated by the control signal, and the first shaft D1 and the second shaft D2 are connected or disconnected.

  When the clutch C is disengaged, a reaction force corresponding to the steering angle of the steering wheel H is applied to the first shaft D1 via the first motor M1, and the steering gear G is transmitted via the second shaft D2 by the second motor M2. Is assisted steered. That is, steering by steer-by-wire is performed.

On the other hand, when the abnormality detection sensor S2 detects a malfunction of the steer-by-wire system, the controller P operates the clutch C based on the abnormality detection signal from the sensor S2 to connect the first shaft 1 and the second shaft 5. Switch to steering by mechanical connection. In this way, in the event that a malfunction occurs in the steer-by-wire system due to a failure of the motors M1, M2, etc., and a malfunction occurs in the vehicle control by the steering H, the fail-safe mechanism works and the steering wheel H can be directly steered. (See Patent Documents 1 and 2).
JP 2001-301039 A JP 2004-351975 A

The clutch C used in this steer-by-wire system has been proposed in various structures (see Patent Documents 1 to 3), most of which are a mechanical type two-way clutch and its two-way clutch. There is a problem that the axial length is long and the weight is heavy, such as a configuration with a large number of parts in which an electromagnetic clutch for controlling on / off of the motor is arranged in parallel in the axial direction (see Patent Document 3). is there.
JP-A-10-59011

  In view of the above circumstances, an object of the present invention is to provide a small, compact and lightweight clutch having a short axial length and a small number of parts in a steer-by-wire system.

  In order to achieve the above object, according to the present invention, in a rotation transmission device that forms a clutch in the above steer-by-wire system or the like, a rotatable inner member coupled to the first shaft D1 or the second shaft D2, An outer member provided on the outer side of the inner member so as to be rotatable on the same axis and connected to the second shaft D2 or the first shaft D1, and between an inner periphery of the outer member and an outer periphery of the inner member The armature is made of a magnetic body that is rotatably assembled around the same axis and is movable in the same axis direction, and is accommodated in a groove formed in a radial direction (orthogonal direction of the same axis) formed on the side surface of the armature. An engagement element that is coupled to one of the inner member and the outer member and engages with the outer periphery of the inner member and the inner periphery of the outer member when the armature is rotated relative to the other, and the engagement element of the inner member A switch spring that elastically holds the armature in a neutral position that is disengaged from the outer periphery of the peripheral member and the outer member, and an axial direction of the armature fixed to the inner periphery of the outer member or the outer periphery of the inner member ( The structure is composed of a rotor facing in the same axial direction) and an electromagnet supported by a stationary member, facing the rotor in the axial direction (the same axial direction), and attracting the armature to the rotor by energization. .

In the rotation transmission device of this configuration, when the energization to the electromagnetic coil of the electromagnet is interrupted (when the electromagnetic coil is not energized), the armature is disconnected from the rotor, the armature is returned to the neutral position by the switch spring, and the engagement element is removed. It becomes non-engaged with respect to the inner periphery of the side member and the outer periphery of the inner member, and transmission of rotational torque between the outer member and the inner member is blocked.
On the other hand, when the electromagnetic coil of the electromagnet is energized, the armature is attracted to the rotor by the magnetic force of the electromagnet due to the energization, and when the outer member or the inner member rotates, the armature resists the switch spring along with the rotation (switch The springs are elastically deformed) and rotate relative to each other, and the engaging element housed in the armature moves from the neutral position and engages with the inner periphery of the outer member and the outer periphery of the inner member, so that the outer member and the inner member Rotational torque is transmitted between the members.

  The rotation transmission device includes, for example, a steering wheel, a first shaft coupled to the steering wheel, a first motor that transmits a steering reaction force to the first shaft, a steering gear, and a first shaft coupled to the steering gear. Two shafts, a second motor that transmits a steering force to the second shaft, and a clutch that is mounted between the first shaft and the second shaft and switches the first shaft and the second shaft to a connected or unconnected state. In the steer-by-wire system, the rotation transmission device is adopted for the clutch, the inner member is connected to the first shaft or the second shaft, and the outer member is connected to the second shaft or the first shaft. Adopted in a steer-by-wire system.

  In this steer-by-wire system, when the rotation transmission device is disconnected by cutting off the energization of the electromagnetic coil of the electromagnet (when the first shaft and the second shaft are disconnected by disengaging the outer member and the inner member), A reaction force corresponding to the steering angle of the steering wheel is applied to the first shaft via the first motor, and the steering gear is assisted and steered via the second shaft by the second motor, and steering by steer-by-wire is performed. .

  On the other hand, when a failure occurs in the steer-by-wire system, the first shaft and the second shaft are connected by the engagement of the outer member and the inner member in the rotation transmission device by energizing the electromagnetic coil of the electromagnet. A fail-safe mechanism works and it can be directly steered by the steering wheel.

  The engagement element may be a roller or a sprag. When a roller is used as an engagement element, a cylindrical surface is formed on one of the inner periphery of the outer member and the outer periphery of the inner member, and a wedge-shaped space whose both ends in the circumferential direction are narrow between the cylindrical surface and the other. A cam surface to be formed is provided, and a roller is assembled between the cam surface and the cylindrical surface.

  On the other hand, when a sprag is used as an engagement element, a cylindrical surface is formed on the inner periphery of the outer member and the outer periphery of the inner member, and the sprag is incorporated between the opposing cylindrical surfaces, and the armature that holds the sprag is divided into two parts. One split armature is fixed to the inner or outer member, and the other split armature is held in the neutral position by applying the elastic force of the switch spring, and the other split armature can be attracted by the electromagnet. And

  Further, the engagement element can be made of a metal plate press-molded product or an aluminum or synthetic resin molded product to reduce the cost.

  The switch spring is elastically deformed by the relative rotation of the armature with respect to the inner member or the outer member, and the engagement element engages with the inner periphery of the outer member and the outer periphery of the inner member by the relative rotation, thereby the inner member. Rotational torque is transmitted between the outer member and the outer member. That is, the first and second shafts are connected. On the other hand, when the armature rotates with respect to the inner member or the outer member, the armature and the engagement element are returned to the neutral position where the engagement is released by the restoring elasticity of the switch spring. Transmission of rotational torque at is interrupted. That is, the first and second shafts are disconnected.

  When the engagement element is accommodated in a radial groove formed on a side surface opposite to the rotor of the armature (when accommodated in a radial groove on the opposite side surface of the storage state in FIG. When the groove passes through the armature and the engaging element passes through), it is preferable that the engaging element is provided with a dropping prevention means for preventing the armature from coming out from the radial groove in the axial direction (the same axial direction). The drop-off prevention means is an annular stopper plate that is attached to the outer periphery of the inner member and is opposed to the armature with a space equal to or less than the thickness of the engaging element in a state where the armature is attracted to the rotor. Can be employed.

In addition, when the rotor is provided with a separation spring, and the armature is urged away from the rotor by this spring, the adsorption of the armature to the rotor is released (when the energization to the electromagnet is cut off) The armature can be reliably separated from the rotor.
Furthermore, when using this rotation transmission device under lubrication with oil, grease, etc., the armature is held in the attracted state by the viscosity of the lubricant interposed between the rotor and the armature, which may cause malfunction. is there. For this reason, when the separation spring is provided, the separation spring is surely separated, so that the malfunction can be prevented.
In this case, it is possible to reduce the axial length of the rotation transmission device by providing a recess that accommodates a part of the separation spring in the rotor.

  In the rotation transmission device according to the present invention, the outer member and the inner member may input rotational torque. That is, the second shaft may be connected to the outer member, the first shaft may be connected to the inner member, or the first shaft may be connected to the outer member, and the second shaft may be connected to the inner member. For example, when the first shaft is connected to the inward member and rotational torque is input by the inward member, when the energization of the electromagnetic coil of the electromagnet is cut off, the engagement force of the outer member is reduced by the elastic force of the switch spring. Since it is held at the neutral position where the engagement with the inner periphery and the outer periphery of the inner member is released, the rotational torque input to the inner member is not transmitted to the outer member, and only the inner member rotates freely. To do.

  When the electromagnetic coil of the electromagnet is energized, the armature is attracted to the rotor. At this time, if the rotor is attached to the outer member, the armature and the engaging element held by the armature are connected to the outer member, and the inner member, the armature and the engaging element rotate relative to each other. The engaging element is pushed into the narrow portion of the wedge-shaped space and engages with the inner periphery of the outer member and the outer periphery of the inner member. By the engagement, the rotation of the inner member is transmitted to the outer member, and the first and second shafts rotate together.

  On the other hand, when the rotor is attached to the inner member, the armature and the engagement element are connected to the inner member, and the outer member, the armature and the engagement element rotate relative to each other, and the relative rotation causes the engagement element to move in the wedge-shaped space. It is pushed into the narrow portion and engages with the inner circumference of the inner member and the outer circumference of the outer member. By the engagement, the rotation of the inner member is transmitted to the outer member, and the first and second shafts rotate together.

  According to the present invention, as described above, the rotational torque is transmitted via the engagement element, so that a rotation transmission device having a large torque capacity can be obtained. In particular, the armature that holds the engagement element and the rotor are arranged opposite to each other in the axial direction, and the electromagnet is arranged opposite to the rotor in the axial direction. And a lightweight electromagnetic rotation transmission device can be obtained.

  This embodiment is employed in the clutch C of the steer-by-wire system shown in FIG. 8, and the configuration and operation of the steer-by-wire system are the same as described above, and the rotation transmission device C is as follows. .

That is, as shown in FIGS. 1 (I) and (II), the rotation transmission device C includes a first shaft 1 as an inner member integrated with or connected to the first shaft D1, and having a large diameter portion 2 as a shaft end. The outer ring 3 as an outer member is provided so as to cover the large diameter portion 2.
The outer ring 3 has an end plate 4, and a second shaft 5 that is integral with or connected to the second shaft D <b> 2 is provided on the end plate 4. The outer ring 3 is arranged coaxially with the first shaft 1, and the outer ring 3 and the first shaft 1 are relatively rotatable by a bearing 6 provided at the shaft end of the first shaft 1. .

A cylindrical surface 7 is formed on the inner periphery of the outer ring 3. On the other hand, a narrow wedge-shaped space is formed on the outer periphery of the large-diameter portion 2 of the first shaft 1. A plurality of cam surfaces 8 are provided at equal intervals in the circumferential direction.
A plate-shaped armature 9 is incorporated between the outer periphery of the large diameter portion 2 and the inner periphery of the outer ring 3. The armature 9 is made of a magnetic material, and a plurality of radial grooves 10 are formed at equal intervals on one side surface of the armature 9 that faces the rotor 18, and a flat roller 11 as an engaging member is provided in each radial groove 10. It is incorporated.

The roller 11 has a disk shape. Since this roller 11 transmits the rotational torque between the first shaft 1 and the outer ring 3 by the engagement of the outer ring 3 with the cylindrical surface 7 and the cam surface 8 of the large diameter portion 2, depending on the magnitude of the transmitted torque. The material is determined appropriately.
For example, when a large torque is transmitted, a high hardness is required, and therefore, it is formed of a magnetic material such as iron. At this time, the roller 11 may be formed by cutting. Or you may form by press punching.
On the other hand, when transmitting a small torque, the roller 11 may be formed by casting or injection molding using a nonmagnetic material such as aluminum or synthetic resin. In this case, since the roller 11 can be formed by molding, a low-cost roller 11 can be obtained.

The large-diameter portion 2 has a spring housing recess 12 formed on one side surface of the first shaft 1 on the shaft end side, and a switch spring 13 is incorporated in the spring housing recess 12.
The switch spring 13 has a C shape, and a pair of pressing pieces 13a are provided outward at both ends thereof. The pair of pressing pieces 13 a is inserted into a notch 15 provided in the armature 9 from a notch 14 formed in the peripheral wall of the spring housing recess 12, and the end surfaces facing the notch 14 and the notch 15 in the circumferential direction are inserted. The armature 9 is elastically held in a neutral position where the rollers 11 are pressed against each other and the roller 11 is disengaged from the cylindrical surface 7 and the cam surface 8 by the pressing.

  An annular stopper plate 16 is fitted to the shaft end portion of the first shaft 1, and the stopper plate 16 abuts on one side surface of the large-diameter portion 2 by a retaining ring 17 attached to the shaft end portion of the first shaft 1. It is held in the state to do. The stopper plate 16 closes the opening of the spring housing recess 12 and prevents the switch spring 13 from coming out of the opening of the spring housing recess 12. Further, the amount of separation of the armature 9 from the rotor 18 is limited.

A rotor 18 made of a magnetic material is provided on the other side of the armature 9. The rotor 18 has cylindrical portions 18 a and 18 b facing in the same direction on the outer periphery and the inner periphery, and the outer cylindrical portion 18 a is press-fitted into the opening end portion of the outer ring 3 and integrated with the outer ring 3.
Here, when the outer ring 3 is made of a magnetic material, a cylindrical rotor guide made of a non-magnetic material is connected to the opening end of the outer ring 3, and the outer cylindrical portion 18a of the rotor 18 is press-fitted into the rotor guide. Magnetic leakage from the rotor 18 to the outer ring 3 may be prevented.

The inner cylindrical portion 18 b of the rotor 18 is rotatably supported by a bearing 19 provided outside the first shaft 1.
An annular recess 20 is formed on the surface of the rotor 18 facing the armature 9, and a separation spring 21 incorporated in the recess 20 urges the armature 9 in a direction away from the rotor 18.

  An electromagnet 22 is incorporated between the outer cylindrical portion 18 a and the inner cylindrical portion 18 b of the rotor 18. The electromagnet 22 includes an electromagnetic coil 22a and a core 22b that supports the electromagnetic coil 22a. The core 22b is supported by a stationary member 23 and is fixedly arranged.

The rotation transmission device of this embodiment has the above-described configuration. FIGS. 1 (I), (II) and FIG. 2 show a state where the electromagnet 22 is de-energized with respect to the electromagnetic coil 22a, and the armature 9 is pressed by the separation spring 21. It is separated from the rotor 18. Further, the roller 11 is held in a neutral position where the engagement with the cylindrical surface 7 and the cam surface 8 is released by the elastic force of the switch spring 13.
For this reason, even if rotational torque is input to the first shaft 1 and the first shaft 1 rotates, the rotation is not transmitted to the outer ring 3 and only the first shaft 1 rotates freely.

When the electromagnetic coil 22a of the electromagnet 22 is energized in the rotation state of the first shaft 1, a magnetic circuit a is formed between the core 22b, the rotor 18 and the armature 9 as shown by a one-dot chain line in FIG. The armature 9 is adsorbed to the outer ring 3, and the armature 9 is coupled to the outer ring 3 through the rotor 18.
For this reason, the first shaft 1 and the armature 9 rotate relative to each other, and the roller 11 engages with the cylindrical surface 7 of the outer ring 3 and the cam surface 8 of the large-diameter portion 2 as shown in FIG. Therefore, the rotation of the first shaft 1 is transmitted to the outer ring 3 via the roller 11, and the outer ring 3 rotates in the same direction as the first shaft 1.

  Further, when the first shaft 1 and the armature 9 are relatively rotated, the switch spring 13 is elastically deformed. Therefore, when the energization of the electromagnet 22 to the electromagnetic coil 22a is cut off, the armature 9 is rotated by the restoring elasticity of the switch spring 13, and the roller 11 is placed on the cylindrical surface 7 and the cam surface 8 as shown in FIG. On the other hand, it is returned to the neutral position where the engagement is released, and the torque transmission from the first shaft 1 to the outer ring 3 is interrupted.

  Thus, since the rotation transmission device shown in this embodiment can engage and disengage the roller 11 by energizing and shutting off the electromagnetic coil 22a, between the first shaft 1 and the outer ring 3. Rotational torque can be transmitted and cut off.

  Further, since the armature 9 has a function of holding the roller 11, the number of parts can be reduced, and the two-way clutch roller 11 is incorporated in the electromagnetic clutch of the conventional rotation transmission device. Therefore, a small, compact and lightweight rotation transmission device having a short axial length can be obtained.

Therefore, in the steer-by-wire system, when the electromagnetic coil 22a of the electromagnet 22 of the rotation transmission device is de-energized, the rotation transmission device is disconnected (the first shaft D1 and the second shaft D2 are disconnected), and the first motor. A reaction force corresponding to the steering angle of the steering wheel H is applied to the first shaft D1 via M1, and the steering gear G is assisted steered via the second shaft D2 by the second motor M2. That is, steering by steer-by-wire is performed.
On the other hand, when a malfunction occurs in the steer-by-wire system, the electromagnetic coil 22a of the electromagnet 22 is energized, and the rotation transmission device operates a fail-safe mechanism in which the first shaft D1 and the second shaft D2 are connected. The wheel H can be directly steered.

  5 (I) and 5 (II) show another embodiment. In this embodiment, a cam surface 24 is provided on the inner periphery of the outer ring 3 and a cylindrical surface 25 is formed on the outer periphery of the large-diameter portion 2. . In this case, the inner cylindrical portion 18 b of the rotor 18 is press-fitted into the first shaft 1, the rotor 18 is fixed to the first shaft 1, and the outer cylindrical portion 18 a of the rotor 18 is incorporated into the opening end of the outer ring 3. The bearing 26 is rotatably supported.

  Further, the switch spring 13 is accommodated in an annular groove 12 ′ formed on the side surface opposite to the surface facing the rotor 18 of the armature 9, and a pair of pressing pieces 13 a provided at both ends of the switch spring 13 are provided to the armature 9. Inserting into the notch part 28 formed in the inner periphery of the outer ring | wheel 3 from the notch 27 formed, and pressing the opposing end surface in the circumferential direction of the notch 27 and the notch part 28 in the opposite direction, the press Thus, the armature 9 is elastically held in a neutral position where the roller 11 is disengaged from the cam surface 24 and the cylindrical surface 25.

  Since other configurations are the same as those in the above embodiment, the same components are denoted by the same reference numerals and description thereof is omitted, and the operations and effects are also the same as those in the above embodiment. The description is omitted.

  6 (I) and 6 (II) show still another embodiment according to the present invention. In this embodiment, the outer periphery of the large-diameter portion 2 and the inner periphery of the outer ring 3 are cylindrical surfaces 29 and 30, respectively. A flat sprag 31 as an engagement element is incorporated between the 29 and 30.

The sprag 31 is formed of a plate, has a low height in the standing state, and gradually increases in height by rotating around the center of gravity, and arc-shaped surfaces 31 a and 31 b provided at both ends engage with the cylindrical surfaces 29 and 30. It is supposed to be. In addition, the arcuate surfaces 31 a and 31 b at both ends in the standing state are in a neutral position where they are not engaged with the cylindrical surfaces 29 and 30.
In addition, the armature 9 is divided into two divided armatures 9a and 9b having different diameters, and the small-diameter side (inner side) divided armature 9b is fixed to the large-diameter portion 2 and is larger than the small-diameter-side divided armature 9b. The split armature 9a on the radial side (outside) is rotatable, and the split armature 9a on the large diameter side can be attracted to the rotor 18 by the electromagnet 22.

  Further, the pressing pieces 13a at both ends of the switch spring 13 are inserted from the notches 32 formed in the small-diameter split armature 9b into the notches 33 provided in the large-diameter split armature 9a. The end surfaces facing each other in the circumferential direction of the portion 33 are pressed in opposite directions, and the split armature 9a on the large-diameter side is elastically held in a neutral position where the sprag 31 is disengaged from the cylindrical surfaces 29 and 30 by the pressing. ing.

  Since other configurations are the same as those of the above-described embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  In the rotation transmission device of this embodiment, when the energization of the electromagnetic coil 22a is interrupted, the sprag 31 is held at a neutral position where the engagement with the cylindrical surfaces 29 and 30 is released as shown in FIG. 6 (II). ing. For this reason, even if rotational torque is input to the first shaft 1 and rotates, the rotation is not transmitted to the outer ring 3 and the first shaft 1 rotates freely.

  When the first shaft 1 rotates in the mode shown in FIG. 6 (II), when the electromagnetic coil 22a is energized, the large-diameter divided armature 9a is attracted to the rotor 18 and is fixed to the first shaft 1. The split armature 9b and the large-diameter side split armature 9a rotate relative to each other, and the sprag 31 rotates and tilts around the center of gravity by the relative rotation, and as shown in FIG. , 30 is engaged. Due to the engagement, the rotation of the first shaft 1 is transmitted to the outer ring 3 via the sprag 31, and the outer ring 3 rotates in the same direction as the first shaft 1.

  Further, the switch spring 13 is elastically deformed by the relative rotation of the small-diameter divided armature 9b and the large-diameter divided armature 9a. For this reason, when the energization to the electromagnetic coil 22a is cut off, the split armature 9a on the large diameter side is rotated by the restoring elasticity of the switch spring 13, and the sprag 31 is moved relative to the cylindrical surfaces 29 and 30 as shown in FIG. Returning to the neutral position where the engagement is released, the transmission of the rotational torque from the first shaft 1 to the outer ring 3 is interrupted.

  Also in this embodiment, similarly to the above-described embodiment, it is possible to obtain a small, compact and lightweight rotation transmission device having a short axial length.

In this embodiment, the same effect can be obtained by fixing the large-diameter-side split armature 9a to the outer ring 3 and allowing the small-diameter-side split armature 9b to rotate freely to lock the switch spring 13. Fixes the rotor 18 to the first shaft 1.

In each embodiment, the surface of the armature 9 with respect to the rotor 18 may be the opposite surface, that is, the exposed surface of the engaging elements 11 and 31 (the surface having the radial groove 10) may be opposite to the opposing surface. . In this way, since the magnetic flux passes through the entire circumference of the armature 9, the magnetic efficiency is improved and the power can be reduced. Further, the interference between the separation spring 21 and the engagement elements 11 and 31 is eliminated, and the operation of the armature 9 becomes smooth.
Further, in each embodiment, the radial groove 10 may be punched in the axial direction (through the armature 9 and the engaging elements 11 and 31 pass). By this punching, the manufacturing cost of the armature 9 can be reduced. When the radial groove 10 penetrates and is on the opposite side surface, the stopper plate 16 is between the armature 9 in a state where the armature 9 is attracted to the rotor 18 and the thickness of the engaging elements 11, 31. It is preferable to prevent the engagement elements 11 and 31 from coming out of the radial groove 10 by being arranged at a position where the following gap is secured.
Furthermore, in each embodiment, the first shaft 1 may be connected (integrated) to the second shaft D2 and the second shaft 5 may be connected to the first shaft D1.

(I) is a longitudinal front view showing a first embodiment of the rotation transmission device according to the present invention, (II) is a cross-sectional view taken along the line II of (I) Sectional drawing which expands and shows the rotor site | part of FIG. 1 (I) Sectional drawing which shows the adsorption | suction state of the armature with respect to the rotor of the rotation transmission apparatus shown in FIG. 1 is a longitudinal sectional side view showing an engagement state of rollers of the rotation transmission device shown in FIG. (I) is a longitudinal sectional front view showing a second embodiment of the rotation transmission device according to the present invention, and (II) is a sectional view taken along the line of (I). (I) is a longitudinal front view showing a third embodiment of the rotation transmission device according to the present invention, and (II) is a cross-sectional view taken along the ha-ha line of (I). FIG. 6 is a longitudinal sectional view showing an engaged state of a sprag of the rotation transmission device shown in FIG. Schematic diagram of an example steer-by-wire system

Explanation of symbols

1 First shaft (first shaft, inward member)
3 Outer ring (outer member)
5 Second shaft (second shaft)
7 Cylindrical surface 8 Cam surface 9 Armature 9a Large diameter side split cage 9b Small diameter side split cage 10 Radial groove 11 Roller (engagement element)
13 Switch spring 18 Rotor 20 Recess 21 Separation spring 22 Electromagnet 22a Electromagnetic coil 23 Stationary member 24 Cam surface 25 Cylindrical surface 29 Cylindrical surface 30 Cylindrical surface 31 Sprag (engagement element)
C Clutch (Rotation transmission device)
D1 first shaft D2 second shaft G steering gear H steering wheel M1 first motor M2 second motor

Claims (8)

In the steer-by-wire system that switches the first shaft (D1) connected to the steering wheel (H) and the second shaft (D2) connected to the steering gear (G) to a connected state or a non-connected state by the clutch (C). A rotation transmission device forming the clutch (C),
A rotatable inner member (1) connected to the first shaft (D1) or the second shaft (D2), and the outer member (1) is rotatably provided on the same axis and rotatably provided on the first shaft (D1) or the second shaft (D2). The outer member (3) connected to the two shafts (D2) or the first shaft (D1), and the same axis between the inner periphery of the outer member (3) and the outer periphery of the inner member (1). Is housed in a radial groove (10) formed on a side surface of the armature (9) formed of a magnetic material incorporated in the armature and movable in the same axial direction, and the armature (9) is accommodated in the armature (9). An engagement element (11) that is coupled to one of the inner member (1) and the outer member (3) and engages with the outer periphery of the inner member (1) and the inner periphery of the outer member (3) during relative rotation with respect to the other. , 31) and the engaging members (11, 31) are the outer periphery and the outer member of the inner member (1). 3) a switch spring (13) that elastically holds the armature (9) in a neutral position that is disengaged from the inner periphery of the inner periphery, and the inner periphery of the outer member (3) or the outer periphery of the inner member (1) The rotor (18) fixed in the axial direction and opposed to the armature (9) in the axial direction, supported by the stationary member (23) and opposed to the rotor (18) in the axial direction, and energized to the rotor (18). A rotation transmission device for a steer-by-wire system, characterized by comprising an electromagnet (22) for adsorbing (9).   A cylindrical surface (7, 25) is formed on one of the outer periphery of the inner member (1) and the inner periphery of the outer member (3), and the other is circumferentially between the cylindrical surface (7, 25). Provided are cam surfaces (8, 24) each having a narrow wedge-shaped space at both ends, and an engaging member engaged with and disengaged from the cam surfaces (8, 24) and the cylindrical surfaces (7, 25). The rotation transmission device for a steer-by-wire system according to claim 1, wherein the rotation transmission device is a roller (11).   A cylindrical surface (29, 30) is formed on each of the outer periphery of the inner member (1) and the inner periphery of the outer member (3), and is engaged with and engaged with both the cylindrical surfaces (29, 30). The engagement member to be released is a sprag (31), the armature (9) is divided into two inside and outside (9a, 9b), and one divided armature (9b) is divided into the inner member (1) or the outer member ( 3) The sprag (31) is held in a neutral position in which the elastic force of the switch spring (13) is applied to the other split armature (9a) to be disengaged from the cylindrical surfaces (29, 30). The rotation transmission device for a steer-by-wire system according to claim 1, wherein the other split armature (9a) can be attracted by the electromagnet (22).   The rotation transmission device for a steer-by-wire system according to any one of claims 1 to 3, wherein the engagement element (11, 31) is a press-formed product.   The rotation transmission device for a steer-by-wire system according to any one of claims 1 to 3, wherein the engagement element (11, 31) is made of a molded product of aluminum or synthetic resin.   The rotation transmission device for a steer-by-wire system according to any one of claims 1 to 5, further comprising a separation spring (21) for urging the armature (9) in a direction away from the rotor (18).   The rotation transmission device for a steer-by-wire system according to claim 6, wherein the rotor (18) is provided with a recess (20) for accommodating a part of the separation spring (21).   When the engaging element (11, 31) is accommodated in a radial groove (10) formed on the side surface opposite to the rotor (18) of the armature (9), the armature (9) is An annular stopper plate (16) that is opposed to the armature (9) in a state of being attracted to the rotor (18) with an interval equal to or less than the thickness of the engaging element (11, 31) is attached to the inner member ( The stopper (16) is attached to the outer periphery of 1) to prevent the engagement element (11, 31) from coming out from the radial groove (10) of the armature (9) in the axial direction. Item 8. A rotation transmission device for a steer-by-wire system according to any one of items 1 to 7.

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