JP2007270986A - Rotation transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light weight compact rotation transmission device with short axial direction length. <P>SOLUTION: This device is employed for a rotation transmission device comprising a main part of a failsafe mechanism for 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 outside of the large diameter part 2 connected to a steering gear, and a disk shape roller 11 built between the cylinder surface and the cam surface is stored in a radial direction groove 10 on one surface of a magnetic body armature 9. A switch spring 13 is built between the armature 9 and the large diameter part 2 and the armature 9 is elastically held at a neutral position where engagement of the roller 11 is released. The rotor 18 pressed in the outer ring 3 is put oppositely to an electromagnet 22. Attraction of the armature 9 to the rotor by the electromagnet 21 is released by excitation of the magnet coil 22a of the electromagnet, the armature 9 and the first shaft 1 are rotated together to return the roller 11 to the neutral position, and torque transmission from the fist shaft 1(steering wheel) to the outer ring (steering gear) is cut off. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation transmission device used for switching between power transmission and cutoff, and a steer-by-wire system employing the rotation transmission device.

In this type of rotation transmission device, an outer ring that covers the large-diameter portion is provided outside an input shaft having a large-diameter portion, a two-way clutch is incorporated between the outer ring and the large-diameter portion, and the two-way clutch is turned on. , OFF is controlled by an electromagnetic clutch (see Patent Document 1).
JP-A-10-59011

  The two-way clutch is formed with a cylindrical surface on the inner periphery of the outer ring, and on the outer periphery of the large-diameter portion is provided with a cam surface that forms a wedge-shaped space with narrow ends in the circumferential direction between the cylindrical surface, The roller assembled between the cam surface and the cylindrical surface is held by a retainer assembled between the outer ring and the large diameter portion, and the spring force of the switch spring is applied to the retainer so that the roller is connected to the cam surface and the cylindrical surface. The cage is elastically held in a neutral position where the engagement with the surface is released.

  On the other hand, the electromagnetic clutch is an armature that is supported by the cage of the two-way clutch and supported so as to be movable in the axial direction, a rotor that is supported by the outer ring and is opposed to the armature in the axial direction, and the rotor An electromagnet opposing in the axial direction, the armature is attracted to the rotor by energizing the electromagnetic coil of the electromagnet, and the input shaft and the cage are rotated relative to each other by the frictional resistance acting on the attracting surface, so that the roller and the cylindrical surface The cam surface is engaged.

  In this rotation transmission device, since the two-way clutch incorporated between the outer ring and the large-diameter portion of the input shaft is a mechanical type two-way clutch having a roller as an engagement element, torque transmission and interruption are performed by an electromagnetic clutch. The torque capacity is larger than that of the rotation transmission device to be switched.

  By the way, in recent years, for example, a steer-by-wire system in which a steering wheel that is an automobile steering wheel and a steering gear that is a steering wheel are not mechanically connected has been developed. This system has advantages such as enabling automatic control of the wheel rudder angle by detecting the vehicle speed, increasing the degree of freedom in the interior layout, and enabling more stable driving and improved drivability of the vehicle. As expected.

This steer-by-wire system generally has a fail-safe mechanism for switching 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, for example, As shown in FIG. 13, a steering wheel H which is an automobile handle, a first shaft D1 connected to the steering wheel H, a steering gear G, a second shaft D2 connected to the steering gear G, A clutch C is provided 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 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 (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 switch the first shaft D1 and the second shaft D2. 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 2 and 3).
JP 2001-301039 A JP 2004-351975 A

  In the conventional rotation transmission device, since the mechanical type two-way clutch and the electromagnetic clutch for controlling on / off of the two-way clutch are arranged in parallel in the axial direction, the rotation transmission device The length in the axial direction is long and heavy, and depending on the application, it may not be usable due to size restrictions, and there are still points to be improved in reducing size and weight.

  This reduction in size and weight is also required when this rotation transmission device is used as the clutch C of the steer-by-wire system.

  In view of the above circumstances, an object of the present invention is to provide a small, compact and lightweight rotation transmission device with a short axial length and a small number of parts.

  In order to achieve the above object, the present invention includes a rotatable inner member, an outer member rotatably provided on the same axis on the outer side of the inner member, an inner periphery and an inner portion of the outer member. An armature made of a magnetic material that is rotatably assembled around the same axis between the outer circumferences of the side members, and a radial direction formed on a side surface of the armature (a direction orthogonal to the same axis) And an engagement member that is accommodated in the groove and is engaged with the outer periphery of the inner member and the inner periphery of the outer member when the armature is coupled to one of the inner member and the outer member and rotates relative to the other. A switch spring that elastically holds the armature in a neutral position where the joint is disengaged from the outer periphery of the inner member and the outer periphery of the outer member, and is fixed to the inner periphery of the outer member or the outer periphery of the inner member. Axially with the armature (same as above A rotor that faces the rotor in the axial direction (the same axial direction) supported by a stationary member, and energized to magnetize the magnet. A configuration comprising an electromagnet that generates a magnetic flux to cancel and separates the armature from the rotor is adopted.

In the rotation transmission device of this configuration, when the energization of the electromagnet to the electromagnetic coil is interrupted (unless the electromagnet coil is energized), the armature is attracted to the rotor by the magnet, and the outer member or the inner member to which the rotor is fixed rotates. Then, the armature rotates relative to the switch spring as the switch rotates (the switch spring is elastically deformed), and the engaging element housed in the armature moves from the neutral position to move the inner periphery and the inner member of the outer member. The rotation torque is transmitted between the outer member and the inner member by engaging with the outer periphery of the outer member.
On the other hand, when the electromagnetic coil of the electromagnet is energized, the magnetic flux of the electromagnet caused by the energization works so as to cancel the magnetic flux (magnetic force) of the magnet. The engaging element is disengaged with respect to the inner periphery of the outer member and the outer periphery of the inner member, and transmission of rotational torque between the outer member and the inner member is interrupted.

  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. Then, one split armature is fixed to the inner member or the outer member, the elastic force of the switch spring is applied to the other split armature and held in the neutral position, and the other split armature is attracted to the magnet. Like that.

  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.

  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.

  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. 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.

  Further, if the separation spring is provided in the rotor and the armature is urged by the spring in a direction away from the rotor, the armature can be reliably separated from the rotor when the magnetic force of the permanent magnet is canceled. 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, the axial length can be reduced by providing the rotor with a recess that accommodates a part of the separation spring.

  In the rotation transmission device according to the present invention, the outer member and the inner member may input rotational torque. For example, in the use of inputting rotational torque by the inner member, the armature is attracted and integrated with the rotor in the non-energized cutoff state with respect to the electromagnetic coil of the electromagnet, and the rotor is attached to the outer member. The armature and the engaging member held by the armature are coupled to the outer member, and the inner member, the armature and the engaging member rotate relative to each other, and the engaging member is pushed into the narrow portion of the wedge-shaped space by the relative rotation. Engage with the inner periphery of the member and the outer periphery of the inner member. By the engagement, the rotation of the inner member is transmitted to the outer member.

  When the electromagnetic coil of the electromagnet is energized, the armature is disconnected from the rotor, and the engaging element is disengaged from the inner periphery of the outer member and the outer periphery of the inner member by the elastic force of the switch spring. Therefore, the rotational torque input to the inner member is not transmitted to the outer member, and only the inner member rotates freely.

  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 when the electromagnetic coil of the electromagnet is de-energized, and the outer member, the armature and the engagement element rotate relative to each other. Due to the relative rotation, the engaging element is pushed into the narrow portion of the wedge-shaped space and engaged with the inner periphery of the inner member and the outer periphery of the outer member. By the engagement, the rotation of the inner member is transmitted to the outer member.

  When rotational torque is input to the outer member, the rotational force of the outer member is transmitted / non-transmitted to the inner member by the same action by energization / non-energization of the electromagnetic coil of the electromagnet.

The rotation transmission device having these configurations can be used in various devices. For example, a first shaft connected to a steering wheel that is an automobile handle and a second shaft connected to a steering gear that is a steering wheel are connected by a clutch. Or it can employ | adopt for the steer-by-wire system switched to a non-connection state.
As the steer-by-wire system, for example, a steering wheel, a first shaft coupled to the steering wheel, a first motor for transmitting a steering reaction force to the first shaft, a steering gear, and the steering gear are coupled. A second shaft, 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 state or a disconnected state. And the clutch has a rotation transmission device of these configurations, the first shaft or the second shaft is connected to the inner member, and the second shaft or the second shaft is connected to the outer member. 1 shaft is connected and the armature is separated from the rotor by the energization so that the first shaft and the second shaft are disconnected. It is possible to adopt a configuration that was.

  In this steer-by-wire system, when the rotation transmission device is disconnected by energizing an electromagnetic coil of an electromagnet (when the first shaft and the second shaft are not connected by disengaging the outer member and the inner member), the first motor A reaction force corresponding to the steering angle of the steering wheel is applied to the first shaft via the steering wheel, and the steering gear is assisted and steered via the second shaft by the second motor, and steering by the steer-by-wire is performed.

  On the other hand, when a malfunction occurs in the steer-by-wire system, the first shaft is engaged by the engagement between the outer member and the inner member in the rotation transmission device by shutting off the energization of the electromagnetic coil of the electromagnet. A fail-safe mechanism in which the second shaft and the second shaft are connected works to enable direct steering by the steering wheel.

  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.

1 to 4 show an embodiment of the present invention. In the rotation transmission device of this embodiment, as shown in FIGS. 1 (I) and (II), a first shaft 1 as an inward member has a large diameter portion. 2 is provided at the end of the shaft, and an 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 on which a second shaft 5 is provided. The outer ring 3 is disposed on the same axis with respect to 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. Yes.

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 a side surface facing the rotor 18 of the armature 9, and a flat roller 11 as an engaging element is incorporated in each radial groove 10. It is.

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, injection molding, or the like 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 groove 20 is formed on the surface of the rotor 18 facing the armature 9, and a permanent magnet 21 is incorporated in the groove 20, and the armature 9 is always attracted to the rotor 18 and integrated with the permanent magnet 21. It has become. At this time, since the roller 11 is also on the permanent magnet 21 side, if the roller 11 is a magnetic body, the movement is restricted by being attracted to the permanent magnet 21.

  Various shapes shown in FIGS. 3 to 6 can be considered for the permanent magnet 21, and the shape of the groove 20 corresponding to the shape is used. At this time, if the wall of the rotor 18 forming the groove 20 penetrates the entire circumference of the groove 20, the rotor 18 separated by the groove 20 by the permanent magnet 21 is integrated. As shown in the drawing, the groove 20 has a bottom at an appropriate position around the groove 20 (the rotor 18 is not divided by the groove 20).

  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. When the electromagnetic coil 22a of the electromagnet 22 is energized, the energization generates a magnetic flux that cancels the magnetic flux (magnetic force) of the permanent magnet 21 (see a in FIG. 6), and the armature 9 is released from being attracted to the rotor 18. Thus, the armature 9 becomes rotatable.

1 (I), (II) and FIG. 2 show a non-energized state of the electromagnet 22 to the electromagnetic coil 22a. The permanent magnet 21 causes the armature 9 to be a rotor. The armature 9 is joined to the outer ring 3 through the rotor 18.
For this reason, the first shaft 1 and the armature 9 rotate relative to the switch spring 13, and the relative rotation causes the roller 11 to move the cylindrical surface 7 and the large diameter portion 2 of the outer ring 3 as shown in FIG. The cam surface 8 is engaged. 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. At this time, as shown in the figure, it is preferable that the permanent magnet 21 is submerged from the surface of the rotor 18 so as not to directly touch the roller 18.

In this rotating state, when the electromagnetic coil 22a of the electromagnet 22 is energized, as shown in FIG. 6, the magnetic flux a of the electromagnetic coil 22a is generated, and the magnetic flux b (magnetic force) of the permanent magnet 21 by the magnetic flux a of the electromagnetic coil 22a is generated. The armature 9 is separated from the rotor 18 by being canceled out. Further, the armature 9 is rotated by the restoring elasticity of the switch spring 13, and the roller 11 is returned to the neutral position where the engagement with the cylindrical surface 7 and the cam surface 8 is released as shown in FIG. Torque transmission from 1 to the outer ring 3 is interrupted.
For this reason, even if rotational torque is input to the first shaft 1 and the first shaft 1 rotates, the armature 9 and the roller 11 rotate together with the first shaft 1 at the neutral position, and the rotation is applied to the outer ring 3. Only the first shaft 1 is freely rotated without being transmitted.

  As described above, the rotation transmission device shown in this embodiment can engage and disengage the roller 11 by energizing and shutting off the electromagnetic coil 22a, so that the rotation between the first shaft 1 and the outer ring 3 can be reduced. The rotation 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.

  FIGS. 8 (I), (II), and FIG. 9 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. is doing. 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.

  10 (I), (II) and FIG. 11 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, 30, respectively. A flat sprag 31 as an engagement element is incorporated between the cylindrical surfaces 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. (See FIG. 10 (II)). Moreover, the arcuate surfaces 31a and 31b at both ends in the standing state are in a neutral position where they are not engaged with the cylindrical surfaces 29 and 30 (see FIG. 11).
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. The permanent magnet 21 attracts the large-diameter divided armature 9a.

  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, in the energized state of the electromagnetic coil 22a, the adsorption of the split armature 9a by the permanent magnet 21 is released by the magnetic flux of the electromagnetic coil 22a, and the sprag 31 has a cylindrical surface as shown in FIG. 29 and 30 are held in a neutral position where the engagement is released. 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.

  In the state where the first shaft 1 is rotated, when the energization to the electromagnetic coil 22a is interrupted (when de-energization is performed), the large-diameter divided armature 9a is attracted to the rotor 18 by the permanent magnet 21, and the first shaft The small-diameter split armature 9b and the large-diameter split armature 9a fixed to 1 rotate relative to each other, and the relative rotation causes the sprag 31 to rotate around the center of gravity and tilt as shown in FIG. 10 (II). Arc-shaped surfaces 31 a and 31 b of the cylindrical surfaces 29 and 30 engage with the cylindrical surfaces 29 and 30. 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. At this time, the switch spring 13 is elastically deformed as shown by the relative rotation of the small-diameter side split armature 9b and the large-diameter side split armature 9a.

  In this state, when the electromagnetic coil 22a is energized again, the large-diameter split armature 9a is disconnected from the rotor 18, the large-diameter split armature 9a is rotated by the restoring elasticity of the switch spring 13, and the sprag 31 is 11 is returned to the neutral position where the engagement with the cylindrical surfaces 29 and 30 is released, and 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. The rotor 18 is fixed to the first shaft 1, and the small-diameter divided armature 9 b is attracted by the permanent magnet 21.

  In each embodiment, it is preferable that the rotor 18 is provided with a separation spring for reliably separating the armature 9 from the rotor 18 when the magnetic force of the permanent magnet 21 is canceled. For example, as shown in FIG. 12, an annular recess 20 ′ is formed on the surface of the rotor 18 facing the armature 9, and a part of the separation spring 21 ′ is incorporated in the depression 20, and the separation spring 21 ′ The armature 9 is urged away from the rotor 18.

  In each embodiment, the surface of the armature 9 with respect to the rotor 18 is the opposite surface, that is, the exposed surface of the engaging elements 11 and 31 (the surface having the radial groove 10) is opposite to the opposing surface. Can do. 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 magnet 21 and the engaging elements 11 and 31 is eliminated, and the operation of the armature 9 becomes smooth.

  Furthermore, in each embodiment, the radial groove 10 may be punched in the axial direction (the armatures 9 and 31 pass through the armature 9). 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.

  If the rotation transmission device of each of the above embodiments is employed in the clutch C of the steer-by-wire system, for example, in the steer-by-wire system of FIG. 13, the first shaft D1 is connected to the first shaft 1 and the second shaft 5 is connected to the first shaft D1. If the two shafts D2 are connected, when the electromagnetic coil 22a of the electromagnet 22 of the rotation transmission device (clutch C) is energized, the rotation transmission device is separated (the first shaft D1 and the second shaft D2 are separated), and the first 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 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, if the energization of the electromagnet 22 to the electromagnetic coil 22a is cut off (if deenergized), the rotation transmission device causes the first shaft D1 and the second shaft D2 to be connected. The connected fail-safe mechanism works, and the steering wheel H can be directly steered.
At this time, the second shaft D2 can be connected to the first shaft 1 and the first shaft D1 can be connected to the second shaft 5.

(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) 1 is a partially cutaway exploded perspective view of the rotor portion of FIG. Right side view of the rotor part Perspective view of each aspect of the permanent magnet Sectional drawing which shows the separation state of the armature with respect to the rotor of the rotation transmission apparatus shown in FIG. 1 is a longitudinal side view showing the idling state of the 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). FIG. 8 is a longitudinal side view showing the idling state of the rollers of the rotation transmission device shown in FIG. (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. 10 is a longitudinal sectional view showing the idling state of the sprag of the rotation transmission device shown in FIG. Vertical front view showing a fourth embodiment of the rotation transmission device according to the present invention Schematic diagram of an example steer-by-wire system

Explanation of symbols

1 First shaft (inner member)
3 Outer ring (outer member)
5 Second shaft 7 Cylindrical surface 8 Cam surface 9 Armature 9a Large diameter side split cage (armature)
9b Small diameter split cage (armature)
10 radial groove 11 roller (engagement element)
13 Switch spring 18 Rotor 20 Groove 21 Permanent magnet 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)

  A rotatable inner member (1), an outer member (3) rotatably provided on the same axis on the outer side of the inner member (1), and inner and inner sides of the outer member (3) Formed on the side surface of the armature (9) and the armature (9) made of a magnetic body that is rotatably assembled around the same axis between the outer peripheries of the side members (1) and is movable in the same axis direction. Received in the radial groove (10), the armature (9) is coupled to one of the inner member (1) and the outer member (3), and the outer periphery of the inner member (1) during relative rotation with respect to the other; Engaging elements (11, 31) engaged with the inner periphery of the outer member (3), and the engaging elements (11, 31) on the outer periphery of the inner member (1) and the inner periphery of the outer member (3). A switch spring (13) which elastically holds the armature (9) in a neutral position where the engagement is released, and the outer portion A rotor (18) fixed to the inner periphery of (3) or the outer periphery of the inner member (1) and opposed to the armature (9) in the axial direction, and the armature (9) provided on the rotor (18) And a magnet (21) that adsorbs the magnet (21) and is opposed to the rotor (18) in the axial direction, supported by a stationary member (23), and generates a magnetic flux that counteracts the magnetic force of the magnet (21) when energized, thereby generating the armature (9). ) And an electromagnet (22) for separating the rotor from the rotor (18).   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 according to claim 1, wherein the rotation transmission device is a roller.   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 parts, one divided armature (9b) is fixed to the inner member (1) or the outer member (3), and the other divided part An elastic force of the switch spring (13) is applied to the armature (9a) to hold the sprag (31) in a neutral position where it is disengaged from the cylindrical surfaces (29, 30), and the other split armature ( The rotation transmission device according to claim 1, wherein 9a) is attracted to the magnet (21).   The rotation transmission device according to any one of claims 1 to 3, wherein the engagement element (11, 31) is a press-formed product.   The rotation transmission device 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.   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 6. The rotation transmission device according to any one of Items 1 to 5.   The said rotor (18) was provided with the separation spring (21 ') which urges | biases the said armature (9) in the direction away from a rotor (18), The one of Claim 1 thru | or 6 characterized by the above-mentioned. Rotation transmission device. A steer-by-wire comprising a clutch (C) for switching 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. In the system,
The rotation transmission device according to any one of claims 1 to 7 is adopted for the clutch (C), the first shaft (D1) or the second shaft (D2) is connected to the inner member (1), The second shaft (D2) or the first shaft (D1) is connected to the outer member (3), and the armature (9) is separated from the rotor (18) by the energization, so that the first shaft (D1) and the first shaft (D1) A steer-by-wire system characterized in that the two shafts (D2) are disconnected.

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