JP2024035546A - Rotation transmission device and steering device - Google Patents

Abstract

An object of the present invention is to facilitate machining of an electromagnet core and a member separated therefrom in an electromagnetic clutch included in a rotation transmission device. The present invention includes a two-way clutch 50 that engages and disengages an inner member 30 and an outer member 21, and an electromagnetic clutch 40 that controls engagement and disengagement of the two-way clutch 50. Reference numeral 40 denotes an electromagnet having an armature 51 that is prevented from rotating with respect to a retainer 54 and is supported so as to be movable in the axial direction, a core 41 facing the armature 51 in the axial direction, and an electromagnetic coil 42 held by the core 41. 44, and a separation elastic member 57 that urges the armature 51 in a direction away from the core 41, and a recess 46 for accommodating the separation elastic member 57 is formed on the surface 41x of the core 41 facing the armature 51. This is a rotation transmission device. [Selection diagram] Figure 2

Description

The present invention relates to a rotation transmission device and a steering device using the rotation transmission device.

2. Description of the Related Art A steer-by-wire type steering device is known as a steering device for a vehicle that changes the direction of steered wheels (generally front wheels) of a vehicle in response to a rotational operation of a steering wheel by a driver. A steer-by-wire steering device includes a steering sensor that detects the amount of operation of the steering wheel, and a steering actuator that is mechanically separated from the steering wheel. It operates according to the detected amount of steering wheel operation and changes the direction of the left and right steered wheels.

As a rotation transmission device used in a steering device, for example, there is one described in Patent Document 1. The rotation transmission device described in Patent Document 1 includes a two-way clutch and engagement and disengagement of the two-way clutch in order to switch between transmission and disconnection of rotation between two coaxially arranged shafts. It is equipped with an electromagnetic clutch for control. A two-way clutch has an inner ring installed inside an outer ring, and a plurality of wedge spaces that narrow toward both ends in the circumferential direction between the inner ring and a cylindrical surface formed on the inner periphery of the outer ring. cam surfaces, and an engager consisting of a roller is incorporated between each cam surface and the cylindrical surface, and the roller is held by a retainer. Further, a switch spring is incorporated between the retainer and the inner ring.

The electromagnetic clutch includes an armature placed opposite the open end of the outer ring, a rotor placed opposite the armature and connected to the outer ring, and an electromagnet placed opposite the rotor. When the electromagnet is not energized, sufficient frictional force does not work between the armature and the rotor, so the retainer and roller are held in a disengaged neutral position by the elastic force of the switch spring. When the armature is attracted to the rotor by energizing the electromagnet, the retainer and inner ring rotate relative to each other against the elastic force of the switch spring, and this relative rotation causes the roller to engage with the cylindrical surface of the outer ring and the cam surface of the inner ring. However, rotational torque can be transmitted between the inner ring and the outer ring.

If the rotation transmission device of Patent Document 1 is used in a steering device, the two-way clutch will be disengaged when steering is performed using a steer-by-wire method, and the two-way clutch will be disengaged when steering is performed by a mechanical connection between the steering wheel and steered wheels. By engaging the two-way clutch, the steering system can be switched. Note that in the case of using only a steer-by-wire type steering device, it is not necessarily necessary to provide a mechanism for mechanically connecting the steering wheel and steered wheels.

By the way, when the steering wheel and steered wheels are mechanically separated, such as in a steer-by-wire system, when the driver operates the steering wheel and the direction of the steered wheels reaches its travel limit (stroke end). The driver can also rotate the steering wheel. Therefore, even though the direction of the steered wheels has reached the stroke end, a problem may arise in that the driver does not notice that the direction of the steered wheels has reached the stroke end. To solve this problem, for example, it is possible to use the two-way clutch and electromagnetic clutch described in Patent Document 1 as a steering lock means for regulating the rotation of the steering wheel at a predetermined time or a predetermined position. .

Japanese Patent Application Publication No. 2019-120341

In a conventional rotation transmission device such as that disclosed in Patent Document 1, a separation spring is provided between the armature and the electromagnet in order to separate the armature and the electromagnet when electricity is turned off to the electromagnet. Further, in order to hold the separation spring, a recess into which the separation spring fits is provided on the opposite surface of the armature on the electromagnet side (see FIG. 1 of Patent Document 1).

Since the armature is a plate-shaped member, it can be formed by press working or the like. However, in order to form the recess for the separation spring, it is necessary to perform a turning process to form the recess after a forming process such as press working. On the other hand, since the core of the electromagnet is formed by forging or the like, it is necessary to perform turning processing to make the facing surface (friction surface) on the armature side flat after forming by forging or the like. Therefore, it is necessary to turn both the armature and the core of the electromagnet, which causes high costs.

SUMMARY OF THE INVENTION An object of the present invention is to facilitate the processing of an electromagnet core and a member to be separated from the electromagnet core in an electromagnetic clutch included in a rotation transmission device.

In order to solve the above-mentioned problems, this invention engages and engages an inner member and an outer member that are coaxially arranged and supported so as to be relatively rotatable around an axis. The two-way clutch includes a two-way clutch to be released, and an electromagnetic clutch to control engagement and disengagement of the two-way clutch, and the two-way clutch is a retainer installed between the inner member and the outer member. a roller that is held by the retainer and is engaged between a cylindrical surface provided on one of the inner member and the outer member and a cam surface provided on the other, and the roller is disengaged; the electromagnetic clutch includes an armature supported movably in the axial direction and prevented from rotating with respect to the retainer; an electromagnet having a core that faces in the axial direction and an electromagnetic coil held by the core; and a separation elastic member that urges the armature in a direction away from the core; The retainer is rotated relative to the inner member around an axis by magnetic attraction, and a recess for accommodating the separating elastic member is formed on the surface of the core facing the armature. A transmission device was adopted.

At this time, a configuration may be adopted in which a surface of the armature facing the core is a flat surface.

The core is an annular member disposed on the outer periphery of the inner member, and at least a portion of the opposing surface of the core in the circumferential direction is divided between an outer diameter side and an inner diameter side. Can be adopted.

Further, the core is an annular member disposed on the outer periphery of the inner member, and the core includes a base portion provided at one end in the axial direction opposite to the side facing the armature, and an outer diameter side of the base portion. an outer diameter side rising portion rising from the end portion toward the other end in the axial direction; and an inner diameter side rising portion rising from the inner diameter side end portion of the base portion toward the other end side in the axial direction; It is possible to employ a configuration in which a part of the radially outer portion is separated between the outer diameter side rising portion and the inner diameter side rising portion.

Further, the core is supported in a case having a cylindrical part, and the core is inserted into the cylindrical part through an opening provided at one end in the axial direction of the case, and the outer diameter surface of the core and the case It is possible to employ a configuration in which a sealing member is interposed between the inner diameter surface and the inner diameter surface.

Rotation around the axis of the steering shaft is transmitted to the inner member or the outer member using the rotation transmission device having each of the above aspects, and the rotation transmission device is arranged on the same axis as the axis of the steering shaft, or , it is possible to employ a steering device provided on an axis different from the axis of the steering shaft.

Further, by using the rotation transmission device having each of the above aspects, the rotation around the axis of the steering shaft is transmitted to the inner member or the outer member, and the direction of the steering member is controlled based on the rotation around the axis of the steering shaft. It is possible to employ a steering device that includes a steering actuator that changes the steering, and a reaction force motor that applies a steering reaction force to the steering shaft between the steering shaft and the inner member or the outer member.

Using the rotation transmission device having each of the above aspects, rotation about the axis of the steering shaft is transmitted to the inner member or the outer member, and the direction of the steering member is changed based on the rotation about the axis of the steering shaft. Transport equipment equipped with a steering device equipped with a steering actuator can be adopted.

In this invention, a recess for inserting the separating elastic member is provided on the core side of the electromagnet, and the turning process on the opposing member side is eliminated, so that costs can be reduced.

A diagram schematically showing a steer-by-wire steering device of the present invention. A vertical cross-sectional view near the rotation transmission device of the first embodiment Enlarged view of main parts in Figure 2 Cross-sectional view along the IV-IV line in Figures 2 and 3 A vertical cross-sectional view showing a modification of the first embodiment A vertical cross-sectional view near the rotation transmission device of the second embodiment Cross-sectional view along line VII-VII in Figure 6 A vertical cross-sectional view near the rotation transmission device of the third embodiment Bottom view of Figure 8

FIG. 1 shows an embodiment of a rotation transmission device according to the present invention and a steering device using the rotation transmission device. This steering device uses a steer-by-wire system that changes the direction of a steering member 3 by converting the amount of operation of a steering wheel 1 by a driver into an electric signal and controlling a steering actuator 2 based on the electric signal. It is something.

As shown in FIG. 1, the steering device includes a steering wheel 1 steered by a driver, a steering shaft 4 connected to the steering wheel 1, a steering sensor 5 that detects the amount of operation of the steering wheel 1, and a steering wheel 1. The steering wheel 1 includes a reaction force motor 6 that applies a steering reaction force to the steering wheel 1 , a steering actuator 2 that is mechanically separated from the steering wheel 1 , and a control section 8 . Further, the rotation of the steering shaft 4 is transmitted to a rotation transmission device 20 provided on the opposite side of the reaction force motor 6.

The steering shaft 4 rotates around the axis together with the steering wheel 1 when the steering wheel 1 is steered. The steering sensor 5 is attached to the steering shaft 4. Examples of the steering sensor 5 include a steering angle sensor that detects the steering angle of the steering wheel 1, a steering torque sensor that detects the steering torque input to the steering wheel 1 by the driver, and the like.

A reaction motor 6 is attached to the steering shaft 4. The reaction motor 6 is an electric motor that generates rotational torque when energized. The reaction motor 6 is connected to the end of the steering shaft 4. The reaction motor 6 applies a steering reaction force to the steering wheel 1 via the steering shaft 4 by inputting rotational torque to the steering shaft 4 .

The steering actuator 2 includes a steering shaft 10, a steering shaft housing 11, a steering motor 12 that moves the steering shaft 10 in the left-right direction of the vehicle, and a steering sensor 13 that detects the position of the steering shaft 10. and has. The steered shaft 10 is supported by a steered shaft housing 11 so as to be movable in the left-right direction of the vehicle. The steered shaft housing 11 accommodates the center portion of the steered shaft 10 such that both left and right ends of the steered shaft 10 protrude from the steered shaft housing 11.

The steering motor 12 and the steering sensor 13 are attached to the steering shaft housing 11. A motion conversion mechanism (not shown) that converts the rotation output by the steering motor 12 into linear motion of the steering shaft 10 is installed between the steering motor 12 and the steering shaft 10 . Both left and right ends of the steered shaft 10 are connected via tie rods 14 to a pair of left and right steered members 3 (in this embodiment, a tire wheel is used as the steered member 3, so these will be referred to as steered wheels 3 hereinafter). When the steered shaft 10 moves in the axial direction, the direction of the pair of left and right steered wheels 3 changes in conjunction with the movement of the steered shaft 10 in the axial direction.

As shown in FIG. 1, the reaction motor 6 and the steering motor 12 are controlled by a control section 8. An external sensor 9, a steering sensor 5, and a steering sensor 13 are electrically connected to the input side of the control unit 8. The external sensor 9 is a vehicle speed sensor or the like that detects the traveling speed of the vehicle. The reaction force motor 6 and the steering actuator 2 are electrically connected to the output side of the control section 8 .

The control unit 8 operates the steering motor 12 according to the amount of operation of the steering wheel 1 detected by the steering sensor 5 and the vehicle running condition (vehicle speed, etc.) detected by the external sensor 9. Control is performed to change the direction of the steered wheels 3. Further, at this time, the control unit 8 controls the reaction force motor 6 to operate so as to generate a steering reaction force of a magnitude corresponding to the operation amount of the steering wheel 1 and the running condition of the vehicle.

(First embodiment)
2 to 4 show main parts of the rotation transmission device 20 according to the first embodiment. As shown in FIG. 2, the reaction motor 6 includes a motor case 6a and a motor shaft 31 that protrudes from the motor case 6a on the side opposite to the steering wheel 1 (see FIG. 1). Hereinafter, the side of the steering wheel 1 with respect to the motor case 6a will be referred to as one axial end, and the opposite side will be referred to as the other axial end. The motor shaft 31 is rotatably supported around an axis by a rolling bearing (not shown) incorporated inside the motor case 6a. Further, the motor shaft 31 is connected to the steering wheel 1 and the steering shaft 4 so as to rotate together with the steering shaft 4. The motor case 6a is fixed to a vehicle body (not shown) so as not to rotate.

The motor shaft 31 is connected to a rotation transmission device 20 provided at the other axial end of the motor case 6a.

The rotation transmission device 20 includes an inner member 30 and an outer member 21 that are coaxially arranged. The outer member 21 is press-fitted into the inner surface of a case 22 fixed to the motor case 6a, and is prevented from coming off by a retaining ring 25. A bolt 24 is inserted into a hole 22d provided in the case 22, and the bolt 24 is screwed into a female screw hole (not shown) provided in the motor case 6a, thereby fixing the case 22 to the motor case 6a. There is. Thereby, the outer member 21 is fixed. Further, the inner member 30 is supported via a bearing 61 with respect to the outer member 21 so as to be freely rotatable about an axis.

As shown in FIG. 2, the case 22 includes a cylindrical portion 22a and an end wall portion 22b that closes the other end of the cylindrical portion 22a in the axial direction. The hole 22d for the bolt 24 is provided in an outer edge protrusion 22c that protrudes in the outer radial direction at one axial end of the cylindrical portion 22a. A plurality of outer edge protrusions 22c and holes 22d are provided along the circumferential direction.

The inner member 30 is composed of a motor shaft 31 and an auxiliary inner member 32 attached to the motor shaft 31, as shown in FIGS. 2 and 3. The auxiliary inner member 32 has an insertion portion 32c that opens at one end in the axial direction, and the motor shaft 31 is inserted into the insertion portion 32c, and the motor shaft 31 and the auxiliary inner member 32 are integrally connected around the axis. Rotate to . In the embodiment, the motor shaft 31 and the auxiliary inner member 32 are coupled by splines 39a, 39b. Note that the connection structure between the motor shaft 31 and the auxiliary inner member 32 is not limited to the spline connection, and may also be a connection structure using, for example, serration connection, press-fitting, or the like. Alternatively, the motor shaft 31 and the auxiliary inner member 32 may be formed as an integral member, and this may be used as the inner member 30.

The auxiliary inner member 32 includes an annular inner ring portion 32b in which an insertion portion 32c of the motor shaft 31 is provided, and a columnar extension portion 32a protruding from the inner ring portion 32b toward the other end in the axial direction. A bearing 61 that rotatably supports the outer member 21 and the auxiliary inner member 32 is provided between the inner diameter surface of the outer member 21 and the outer diameter surface of the inner ring portion 32b of the auxiliary inner member 32. It is press-fitted and is prevented from coming off by retaining rings 62 and 63.

The rotation transmission device 20 also includes a two-way clutch 50 that switches the outer member 21 and the auxiliary inner member 32 between a rotatable state and a non-rotatable state, and an engagement of the two-way clutch 50. The electromagnetic clutch 40 is provided to control release when the clutch is closed. The two-way clutch 50 and the electromagnetic clutch 40 function as steering lock means that restricts the rotation of the steering wheel 1 and the steering shaft 4 at a predetermined time or a predetermined position.

The two-way clutch 50 includes an outer member 21 and an auxiliary inner member 32, a roller 55 as an engager incorporated between opposing portions of the outer member 21 and the auxiliary inner member 32, and a roller 55 that holds the roller 55. It is equipped with an annular retainer 54 and the like. On the outer periphery of the auxiliary inner member 32, there are a plurality of flat cam surfaces 33 that form a wedge space that is narrow at both circumferential ends with the cylindrical surface 23 formed on the inner periphery of the outer member 21. They are formed at equal intervals along the circumferential direction. The roller 55 has a cylindrical shape and is installed between the cam surface 33 and the cylindrical surface 23.

Pockets 54a are formed in the retainer 54 at positions facing the cam surface 33 of the auxiliary inner member 32 in the radial direction, and rollers 55 are accommodated in each of the pockets 54a (see FIG. 2). When the retainer 54 rotates around the axis relative to the auxiliary inner member 32, the roller 55 engages with the cylindrical surface 23 and the cam surface 33 to connect the outer member 21 and the auxiliary inner member 32. , locks the rotation of the inner member 30 around the axis.

At the other axial end of the inner ring portion 32b of the auxiliary inner member 32, there is a neutral holding elastic member 53 that elastically holds the retainer 54 at a neutral position where the roller 55 disengages from the cylindrical surface 23 and the cam surface 33. It is provided. The neutral holding elastic member 53 is accommodated in a recess 32d provided at the other axial end of the inner ring portion 32b (see FIG. 3). In this embodiment, a switch spring shown in FIG. 4 is used as the neutral holding elastic member 53, but other types of springs or the like may be used.

As shown in FIG. 4, the neutral holding elastic member 53 made of a switch spring has a ring portion 53b formed by bending a wire rod into a circumferential shape, and a pair of engaging pieces 53a, 53a protruding outward from both ends of the ring portion 53b. It is said that the configuration is set up as follows. In the switch spring, the ring portion 53b is fitted into the annular recess 32d of the inner ring portion 32b, and the pair of engagement pieces 53a pass through the notch 32e formed in the outer peripheral wall of the auxiliary inner member 32. It is inserted into a notch 54a formed at one end of the retainer 54. By incorporating the switch spring, the pair of engaging pieces 53a, 53a press both circumferentially opposing end walls of the notch 32e and the notch 54a in opposite directions. Due to the pressure, the retainer 54 is elastically held at a neutral position where the roller 55 disengages from the cylindrical surface 23 and the cam surface 33. That is, when the switch spring is elastically deformed due to relative rotation of the retainer 54 with respect to the auxiliary inner member 32, the switch spring biases the retainer 54 in the circumferential direction so that the roller 55 is maintained at the neutral position by its elastic force. .

The electromagnetic clutch 40 includes a connecting member 52 that is prevented from rotating with respect to a retainer 54 and is supported to be movable in the axial direction with respect to the retainer 54, and an armature provided at the other end of the connecting member 52 in the axial direction. 51, and an electromagnet 44 that is rotatably supported around the axis of the armature 51 and faces the armature 51 in the axial direction.

The connecting member 52 is composed of an annular plate-like member, and as shown in FIG. 3, the inner diameter side edge of the connecting member 52 fits into the outer periphery of the extension portion 32a of the auxiliary inner member 32 and is prevented from coming off by a retaining ring 58. ing. The connecting member 52 rotates around the axis together with the retainer 54 when an engaging portion 52b provided at at least one location in the circumferential direction enters a notch 54b provided at the other end of the retainer 54 in the axial direction. In this embodiment, the connecting member 52 is formed of an annular plate-like member, and the connecting member 52 has a hole in its inner diameter portion through which the inner member 30 (auxiliary inner member 32) is tightly inserted. It may be composed of members having various shapes. Further, the structure for connecting the connecting member 52 and the retainer 54 so that they cannot rotate relative to each other around the axis is not limited to this embodiment, and various structures can be adopted.

The electromagnet 44 includes an electromagnet core (field core) 41 made of a magnetic material, and an electromagnetic coil (solenoid coil) 42 held in a recess 41d of the electromagnet core 41. The electromagnetic core 41 (hereinafter simply referred to as the core 41) is inserted into the inner part of the case 22, that is, the end on the other axial end side of the case 22, and is prevented from coming off by a retaining ring 45. The electromagnet 44 forms an annular magnetic path passing through the core 41 and the armature 51 by energizing the electromagnetic coil 42, thereby attracting the armature 51 to the core 41. Energization and de-energization of the electromagnet 44 are switched based on a command from an external control device (not shown).

As shown in FIGS. 2 and 3, the core 41 is comprised of an annular portion disposed around the outer periphery of the inner member 30. Armature 51 and core 41 are opposed to each other in the axial direction. The core 41 includes a base portion 41c provided at the other end in the axial direction opposite to the side facing the armature 51, an outer diameter side rising portion 41a rising from the outer diameter side end of the base portion 41c toward one end in the axial direction, and the base portion 41c. The inner diameter side rising portion 41b rises from the inner diameter side end portion toward one end in the axial direction. The outer diameter side rising portion 41a and the inner diameter side rising portion 41b each form a cylindrical shape, and the outer diameter side rising portion 41a, the inner diameter side rising portion 41b, and the base portion 41c form a U-shaped cross section over the entire circumference in the circumferential direction. It constitutes a cylindrical member. An opposing surface 41x of the core 41 on one axial end side faces an opposing surface 51x of the armature 51 on the other axial end side. Further, the core 41 is made of a magnetic material, and is fixed to the case 22 so as not to be relatively rotatable.

Here, the fixing orientation of the core 41 and the case 22 is determined by the positioning protrusion 43a provided on the other end of the core 41 in the axial direction entering the recess 43b provided in the end wall portion 22b of the case 22. Ru. Moreover, the engagement between the protrusion 43a and the recess 43b more reliably prevents relative rotation between the core 41 and the case 22. In the embodiment, the protrusion 43a is located at one location around the axis, and the recess 43b is also located at one location around the axis, but the number of locations and the direction of installation can be changed as appropriate according to specifications.

Note that a cable insertion hole 41e is provided in the end wall portion 22b on the other axial end side of the case 22 and the base 41c of the core 41, and the electric wire cable for electricity supply is passed through the cable insertion hole 41e to the electromagnet. 44. Electricity is supplied to the electromagnetic coil 42 from an external power source through a wire cable.

The connecting member 52 includes a connecting protrusion 52a at at least one location on its outer diameter side end. Further, the armature 51 includes an engaging portion 51a into which a connecting protrusion 52a can fit into at least one portion of the outer diameter side end portion thereof. The connecting protrusion 52a of the connecting member 52 engages with the engaging portion 51a of the armature 51, so that the armature 51 and the connecting member 52 are connected so that they cannot rotate relative to each other around the axis. Note that a slight relative rotation (play) between the armature 51 and the connecting member 52 in the circumferential direction is allowed. This also applies between the retainer 54 and the connecting member 52.

The connecting protrusion 52a is inserted into an engaging portion (detent hole) 51a provided in the armature 51 so as to be slidable in the axial direction. Therefore, when the armature 51 moves in the axial direction, the connecting protrusion 52a moves back and forth within the engaging portion (detent hole) 51a, thereby guiding the axial movement of the armature 51. As described above, the connecting member 52 and the retainer 54 rotate together around the axis, and the connecting member 52 is immobile in the axial direction. Therefore, the armature 51 is prevented from rotating relative to the retainer 54, and is not held. It is in a state where it is supported movably in the axial direction with respect to the container 54.

FIG. 4 shows a state in which energization to the electromagnet 44 of the electromagnetic clutch 40 is cut off. In this state, the roller (engager) 55 of the two-way clutch 50 is held at a neutral position where it disengages from the cylindrical surface 23 of the outer member 21 and the cam surface 33 of the inner member 30. That is, the roller 55 is located near the center of the cam surface 33 (near the center in the circumferential direction), and the two-way clutch 50 is in a disengaged state.

When the electromagnet 44 is energized and the armature 51 is magnetically attracted by the magnetic force generated by the electromagnet 44, the retainer 54 is moved against the armature 51 which is attracted and fixed to the electromagnet 44 side in response to rotational input from the inner member 30 side. , and the connecting member 52 connected thereto, attempt to rotate relative to the inner member 30 around the axis. Due to the relative rotation between the retainer 54 and the inner member 30, the roller 55 engages with the cylindrical surface 23 of the outer member 21 and the cam surface 33 of the inner member 30, and the two-way clutch 50 becomes engaged. . As a result, the rotation of the inner member 30 is locked, so rotation of the steering wheel 1 and the steering shaft 4 around the axis is restricted.

When the retainer 54 and the inner member 30 rotate relative to each other, the end face of the notch 32e of the inner member 30 shown in FIG. 4 and the end face of the notch 54a of the retainer 54 are displaced in the circumferential direction, and the switch spring As the engaging pieces 53a, 53a of 53 approach each other, the ring portion 53b is elastically deformed and reduced in diameter. Therefore, when the electromagnet 44 is de-energized, the retainer 54 rotates back due to the restoring elasticity of the switch spring 53, and is returned to the neutral position where the roller 55 is disengaged. As a result, the two-way clutch 50 is disengaged. By releasing the engagement, the rotation of the inner member 30 is unlocked, and the steering wheel 1 and the steering shaft 4 become rotatable.

When the driver operates the steering wheel 1 and the direction of the steered wheels 3 reaches the travel limit (stroke end) on either side, based on information from the steering sensor 5, the steered sensor 13, etc. The two-way clutch 50 is set in advance to be locked. Furthermore, the two-way clutch 50 is set in advance to be unlocked when the driver operates the steering wheel 1 in the opposite direction from the locked state. This restricts excessive rotation of the steering wheel 1 and steering shaft 4.

Here, a separation elastic member (separation spring) 57 is installed between the opposing surface 41x of the core 41 and the opposing surface 51x of the armature 51. The armature 51 is urged in a direction away from the core 41 by the separating elastic member 57 .

The separation elastic member 57 is accommodated in a recess 46 formed in a surface 41x of the core 41 facing the armature 51. On the other hand, it is desirable that the surface 51x of the armature 51 facing the core 41 be a flat surface.

As the separation elastic member 57, various elastic members such as a coil spring, a disc spring, a leaf spring, and the like can be used. In this embodiment, an annular disc spring disposed on the outer periphery of the inner member 30 is used as the elastic member 57 for separation, and the recess 46 is formed continuously around the entire circumference of the axis in accordance with the form of the elastic member 57 for separation. However, the embodiment is not limited to this embodiment, and the type of the separating elastic member 57 can be changed as appropriate, and the form of the recess 46 can also be changed as appropriate according to the form of the separating elastic member 57. For example, when a plurality of coil springs arranged along the outer periphery of the inner member 30 are used as the elastic member 57 for separation, the recess 46 is formed around the axis according to the form of the elastic member 57 for separation. A plurality of intermittent recesses may also be provided.

In the conventional technique, turning is performed to provide a recess (groove) for receiving the separating elastic member 57 on the opposing surface 51x (friction surface) of the armature 51. Since the armature 51 is a plate-shaped member, the outer diameter side of the material of the armature 51 is usually chucked for turning after a forming process such as press working. Therefore, the material of the armature 51 may be deformed by the tightening force of the chuck, resulting in poor flatness and unstable friction torque. However, according to the present invention, since the turning process for the armature 51 can be omitted, deterioration of the flatness of the armature 51 can be prevented, and the friction torque with the electromagnet 44 can be stabilized.

Note that since the core 41 is formed by forging or the like, it is necessary to perform a turning process to make the opposing surface 41x (friction surface) on the armature 51 side flat after forming by forging or the like. Therefore, no new work process is required for turning the recess 46 on the facing surface 41x of the core 41.

Further, in the conventional technique, since a recess is provided in the opposing surface 51x of the armature 51, there is a problem in that the wall thickness of the armature 51 is partially thinned at the location where the recess is provided. If the wall thickness of the armature 51 becomes partially thin, the magnetic path becomes narrower, so it is necessary to set the entire wall thickness of the armature 51 thick to prevent magnetic saturation. However, according to the present invention, since there is no need to provide a recess in the armature 51, the wall thickness of the armature itself can be set thinner, and the total length of the rotation transmission device 20 in the axial direction can be shortened.

Further, in this embodiment, the opposing surface 41x of the core 41 is continuously divided over the entire circumferential direction between the outer diameter side upright portion 41a and the inner diameter side upright portion 41b. That is, the core 41 has a U-shaped cross section consisting of a base portion 41c, an outer diameter side raised portion 41a, and an inner diameter side raised portion 41b, and the opposing surface 41x is divided into an inner diameter side and an outer diameter side. Therefore, when the armature 51 is attracted, a magnetic path passing through the armature 51 is easily formed, and high attraction performance can be exhibited. Further, from the viewpoint of ensuring a magnetic path, it is desirable that the outer diameter side rising portion 41a and the inner diameter side rising portion 41b of the core 41 are connected only through the base portion 41c. Note that it is desirable that the division between the inner diameter side and the outer diameter side of the facing surface 41x be continuous over the entire circumference in the circumferential direction as in this embodiment. A mode in which only the direction is considered is also conceivable.

Here, the recessed portion 46 may be provided on the opposing surface 41x on the side of the outer diameter side upright portion 41a, or may be provided on the opposing surface 41x on the side of the inner diameter side upright portion 41b. In this embodiment, the inner diameter side rising portion 41b is formed to be thicker than the outer diameter side rising portion 41a (thicker in the radial direction), and the relatively thick inner diameter side rising portion 41b has a recess. 46 prevents a decrease in the strength of the core 41 and also reduces the size of the separation elastic member 57.

By the way, the core 41 of the electromagnet 44 is supported within the case 22 having the cylindrical portion 22a, and the core 41 and the case 22 are made of different materials. For example, in this embodiment, the core 41 is made of a magnetic material (made of steel), and the case 22 is made of aluminum for the purpose of preventing magnetic leakage.

Here, the radial support (support in the radial direction) of the electromagnet 44 is performed between the inner diameter surface of the case 22 and the outer diameter surface of the core 41 of the electromagnet 44. For this reason, conventionally, in order to ensure accurate coaxiality of the electromagnet 44 and the two-way clutch 50, the dimensional accuracy of the inner diameter surface of the case 22 and the outer diameter surface of the electromagnet 44 (the outer diameter surface of the core 41) has been improved to some extent. There was a problem in that the processing was costly. Furthermore, when the core 41 and the case 22 are made of different materials as in the embodiment, a gap is created between the inner diameter surface of the case 22 and the outer diameter surface of the electromagnet 44 at high temperatures due to the difference in linear expansion coefficient of the materials. There was also the problem that accurate coaxial alignment could not be ensured. Furthermore, if vibrations and the like continue to be applied with this gap created, there is a possibility that abnormalities such as fretting wear may occur between the inner diameter surface of the case 22 and the outer diameter surface of the electromagnet 44.

Therefore, in this embodiment, an elastic member 44a made of an elastic material such as rubber is interposed between the outer diameter surface of the core 41 and the inner diameter surface of the cylindrical portion 22a of the case 22. By pressing and fixing the core 41 of the electromagnet 44 to the case 22 by the elastic member 44a, the dimensional tolerance between the outer diameter surface of the electromagnet 44 and the inner diameter surface of the case 22 can be increased, and processing costs can be reduced. can. Furthermore, occurrence of fretting wear and the like between the outer diameter surface of the electromagnet 44 and the inner diameter surface of the case 22 can be suppressed.

Here, the elastic member 44a may be a part of the electromagnet 44 and the case 22 along the circumferential direction, but it is preferably an annular member that extends all the way around the circumferential direction as in the embodiment. The elastic member 44a may be accommodated in a groove 44b provided in the case 22, as shown in FIG. 2, or may be accommodated in a groove 44b provided in the core 41, as in a modified example shown in FIG. Good too.

(Second embodiment)
A second embodiment of this invention is shown in FIGS. 6 and 7. The basic configuration of the device is the same as that of the first embodiment, so a description thereof will be omitted, and the following will focus on the differences (the same applies to the third embodiment described later).

In the first embodiment, the core 41 of the electromagnet 44 has an integral structure, whereas in the second embodiment, the core 41 of the electromagnet 44 is composed of a plurality of parts. Specifically, the core 41 includes a base 41g on the armature 51 side, an outer diameter rising portion 41a rising from the outer diameter end of the base 41g toward the other end in the axial direction, and an inner diameter end of the base 41g. It is composed of a core body 41h having a U-shaped cross section and an inner diameter side rising portion 41b rising from the center toward the other end in the axial direction, and an electromagnetic plate 47 that is a separate member from the core body 41h. The electromagnetic plate 47 closes an opening at the other end in the axial direction of the core body 41h, which has a U-shaped cross section. Reference numeral 49 in FIG. 6 indicates an electromagnetic bobbin, and reference numeral 47a indicates a cable insertion hole. The core body 41h and the electromagnetic plate 47 are made of magnetic material.

In the first embodiment described above, the core 41 has a U-shaped cross section with the opposing surface 41x open, but in the second embodiment, the surface opposite to the opposing surface 41x is open. It has a U-shaped cross section, and a plurality of arc-shaped slits 41f are provided on the opposing surface 41x. By providing this slit 41f, the opposing surface 41x is divided into an inner diameter side and an outer diameter side at the location where the slit 41f is provided. The effect of dividing the opposing surface 41x into the inner diameter side and the outer diameter side is the same as in the first embodiment.

The electromagnet plate 47 is an annular plate, and the plate is press-fitted and fixed to the outer diameter surface of the inner diameter side upright portion 41b of the core body 41h. The core body 41h and the electromagnetic plate 47 sandwich an electromagnetic bobbin 49 made of resin. The function of the electromagnet 44 is the same in the first embodiment and the second embodiment, but when the mass production quantity is relatively small, the structure of the first embodiment is used, and when the mass production quantity is relatively large, the structure is the same. It is effective to adopt the structure of the second embodiment.

Here, the recess 46 that accommodates the separation elastic member 57 may be provided on the outer diameter side of the slit 41f, or may be provided on the inner diameter side of the slit 41f. In this embodiment, the width on the inner diameter side of the slit 41f is longer than the width on the outer diameter side (both are longer in the radial direction), and the recess 46 is formed in the relatively wide inner diameter side portion. By forming this, the strength of the core 41 is prevented from decreasing.

(Third embodiment)
A third embodiment of this invention is shown in FIGS. 8 and 9. In the third embodiment, the structure of the case 22, the structure of the electromagnet 44, and the fixing structure between the case 22 and the electromagnet 44 are changed from the first embodiment and the second embodiment.

In the first embodiment and the second embodiment, the case 22 is cup-shaped and includes a cylindrical portion 22a and an end wall portion 22b that closes the other end of the cylindrical portion 22a in the axial direction. It was inserted into the case through an opening at one end in the axial direction. During this insertion, it is necessary to match the orientation of the positioning protrusion 43a of the core 41 with the orientation of the recess 43b of the end wall 22b at the bottom of the case 22. The bottom of 22 cannot be seen. For this reason, there was a problem in that it was difficult to detect the phase shift and it was difficult to insert the electromagnet in the correct position.

Therefore, in the third embodiment, as shown in FIG. 8, an opening 27 is provided at the other end of the case 22 in the axial direction, that is, the end opposite to the motor shaft 31 side, and the electromagnet 44 is connected to the other end in the axial direction. It is inserted into the case 22 through an opening 27 on the end side.

The case 22 includes an outer edge protrusion 22c that protrudes in the outer radial direction at one axial end of a cylindrical portion 22a. A bolt 24 is inserted into a hole 22d provided in the outer edge protrusion 22c, and the bolt 24 is screwed into a female screw hole (not shown) provided in the motor case 6a, thereby fixing the case 22 to the motor case 6a. has been done. A plurality of outer edge protrusions 22c and holes 22d are provided along the circumferential direction. In this embodiment, as shown in FIG. 9, the outer edge protrusion 22c and the hole 22d are each provided at three locations along the circumferential direction.

As shown in FIG. 8, the core 41 of the electromagnet 44 is composed of an annular portion disposed on the outer periphery of the inner member 30 and a base portion 41k that closes the other end in the axial direction of the space in the center of the annular portion. There is. . Similar to the first embodiment, the annular portion of the core 41 includes a base portion 41c provided at the other end in the axial direction, and an outer diameter side rising portion 41a rising from the outer diameter side end of the base portion 41c toward one end in the axial direction. It includes an inner diameter side rising portion 41b rising from the inner diameter side end portion of the base portion 41c toward one end in the axial direction. The outer diameter side rising portion 41a and the inner diameter side rising portion 41b each form a cylindrical shape, and the outer diameter side rising portion 41a, the inner diameter side rising portion 41b, and the base portion 41c form a U-shaped cross section over the entire circumference in the circumferential direction. It constitutes a cylindrical member. An opposing surface 41x of the core 41 on one axial end side faces an opposing surface 51x of the armature 51 on the other axial end side. The base portion 41k is a plate-like member that is integral with the base portion 41c so as to connect the base portions 41c on both sides across the axis.

The case 22 includes an outer edge protrusion 21h that protrudes in the outer radial direction at the other axial end of the cylindrical portion 22a. A female screw hole 21i is formed in the outer edge protrusion 21h. Further, the core 41 includes an outer edge protrusion 41i that protrudes in the outer radial direction at the other end in the axial direction. The electromagnet 44 is fixed to the case 22 by inserting a bolt 26 into a hole 41j provided in an outer edge protrusion 41i of the core 41 and screwing the bolt 26 into a female screw hole 21i of the case 22. In this way, by fixing the electromagnet 44 to the case 22 with screws, it is possible to eliminate the need for phase alignment between the positioning protrusion 43a of the core 41 and the recess 43b of the case 22 (see FIG. 2) as in the previous embodiment. There is.

Further, as shown in FIG. 8, a seal member 44c is interposed between the outer diameter surface of the core 41 and the inner diameter surface of the case 22. The seal member 44c is made of a water-stopping material such as rubber. In this embodiment, the other end of the electromagnet 44 in the axial direction is exposed to the external environment outside the case 22, so it is desirable to provide such a seal member 44c. Moreover, since the electric wire cable leading to the electromagnet 44 is pulled out to the outside via a grommet fitted in the cable insertion hole 41e, the sealing performance of the cable pull-out position is ensured.

Here, the seal member 44c is an annular member that extends all the way around the electromagnet 44 and the case 22 in the circumferential direction. The sealing member 44c may be accommodated in a groove 44b provided in the case 22, as shown in FIG. 8, or may be modified and accommodated in a groove 44b provided in the core 41. Further, the same member may serve as the elastic member 44a in the first embodiment and the second embodiment and the seal member 44c in the third embodiment. Note that if the surface of the core 41 of the electromagnet 44, especially the outer peripheral surface of the core 41, is subjected to surface treatment such as roughening, the frictional force between the electromagnet 44 and the case 22 will increase, and the friction between the electromagnet 44 and the case 22 will increase. It is possible to prevent looseness between the parts and suppress wear.

In each of the above embodiments, the axis of the rotation transmission device 20, that is, the axis of the inner member 30 and the outer member 21, is arranged on the same axis as the axis of the steering shaft 4, but other than this embodiment. Alternatively, for example, a configuration may be adopted in which the axis of the rotation transmission device 20 is provided on a different axis from the axis of the steering shaft 4.

In each of the above embodiments, the two-way clutch 50 has a configuration in which the cylindrical surface 23 is provided on the inner periphery of the outer member 21 and the cam surface 33 is provided on the outer periphery of the inner member 30. A two-way clutch 50 having a cylindrical surface on the outer periphery of the outer member 30 and a cam surface on the inner periphery of the outer member 21 may be adopted.

Furthermore, in each of the above embodiments, the steering wheel 1 is provided with a reaction force motor 6 that applies a steering reaction force, and the reaction force motor 6 is provided between the steering shaft 4 and the inner member 30 (rotation transmission device 20). However, the position of the reaction motor 6 can be freely set without being limited to this embodiment. For example, the motor shaft 31 may be extended to protrude toward the other end of the rotation transmission device 20 in the axial direction, and the reaction motor 6 may be provided at the end of the protruded motor shaft.

Furthermore, the inside and outside of each of the above embodiments may be reversed so that the inner member 30 is fixed and the outer member 21 is supported to be rotatable about an axis with respect to the inner member 30. In this case, the rotation of the steering shaft 4 around the axis is input to the outer member 21.

In each of the above embodiments, the rotation transmission device 20 is exemplified using the two-way clutch 50 and the electromagnetic clutch 40 as steering locking means for regulating the rotation of the steering wheel 1 and the steering shaft 4 at a predetermined time or a predetermined position. Although the contents of the present invention have been described, the present invention is not limited to the above embodiments. For example, when the rotation transmission device of Patent Document 1 is used in a steering device, in order to switch between transmission and disconnection of rotation between two coaxially arranged shafts, a two-way clutch 50, The present invention can also be applied to the rotation transmission device 20 including the electromagnetic clutch 40 that controls engagement and release of the two-way clutch 50. In this case, the two-way clutch 50 is disengaged when steering is performed using a steer-by-wire system, and the two-way clutch 50 is disengaged when steering is performed by mechanically connecting the steering wheel 1, steering shaft 4, and steered wheels 3. By engaging the steering wheel, the steering system can be switched.

Further, in each of the above embodiments, the configuration of the present invention has been explained using a steer-by-wire type steering device as an example, but the present invention is not limited to this embodiment, and the present invention can be applied to various vehicles other than the steer-by-wire type. It can also be used in steering devices for vehicles, steering devices for vehicles other than vehicles, and various other devices. Note that in the vehicle steering system of the embodiment, a tire wheel is used as the steering member 3, so this is referred to as a steering wheel 3. In transportation equipment (e.g., ships, aircraft, etc.) equipped with a steering device that rotates the steering shaft 4 around its axis when operated, and that rotation moves a rudder (rudder) left and right, the steering member 3 is a rudder (rudder). ).

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

1 Steering wheel 2 Steering actuator 3 Steering member 4 Steering shaft 6 Reaction force motor 20 Rotation transmission device 21 Outer member 30 Inner member 31 Motor shaft 32 Auxiliary inner member 40 Electromagnetic clutch 41 Core 41a Outer diameter side rising portion 41b Inner diameter side standing portion 41c Base portions 41x, 51x Opposing surface 42 Electromagnetic coil 44 Electromagnet 50 Two-way clutch 51 Armature 53 Neutral holding elastic member 54 Retainer 55 Roller 57 Separation elastic member

Claims (8)

Engagement and engagement of the inner member (30) and the outer member (21), which are coaxially arranged and supported so as to be relatively rotatable about the axis. A two-way clutch (50) to be released, and an electromagnetic clutch (40) to control engagement and disengagement of the two-way clutch (50),
The two-way clutch (50) includes a retainer (54) incorporated between the inner member (30) and the outer member (21), and a retainer (54) held by the retainer (54) and the inner A roller (55) engaged between a cylindrical surface provided on one of the member (30) and the outer member (21) and a cam surface provided on the other, and the roller (55) disengaged. a neutral holding elastic member (53) that urges the retainer (54) to a neutral position,
The electromagnetic clutch (40) includes an armature (51) that is prevented from rotating relative to the retainer (54) and is supported so as to be movable in the axial direction, and a core (41) that faces the armature (51) in the axial direction. ) and an electromagnetic coil (42) held by the core (41); and a separation elastic member (57) that urges the armature (51) in a direction away from the core (41). ), the armature (51) is magnetically attracted by energizing the electromagnet (44), and the retainer (54) is rotated relative to the inner member (30) around an axis;
A rotation transmission device in which a recess (46) for accommodating the separation elastic member (57) is formed on a surface (41x) of the core (41) facing the armature (51). The rotation transmission device according to claim 1, wherein a surface (51x) of the armature (51) facing the core (41) is a flat surface. The core (41) is an annular member disposed on the outer periphery of the inner member (30), and at least a portion of the opposing surface (41x) of the core (41) in the circumferential direction is on the outer diameter side. The rotation transmission device according to claim 1 or 2, wherein the rotation transmission device is separated from the inner diameter side. The core (41) is an annular member disposed on the outer periphery of the inner member (30), and the core (41) is located at the other end in the axial direction opposite to the side facing the armature (51). A base (41c) provided, an outer diameter side rising portion (41a) rising from an outer diameter end of the base (41c) to one end in the axial direction, and one end in the axial direction from the inner diameter end of the base (41c). an inner diameter side rising part (41b) rising toward the side, at least a part of the opposing surface (41x) of the core (41) in the circumferential direction is formed by the outer diameter side rising part (41a) and the inner diameter side rising part (41b) The rotation transmission device according to claim 1 or 2, wherein the rotation transmission device is separated between (41b) and (41b). The core (41) is supported within a case (22) having a cylindrical portion (22a), and the core (41) is inserted into the cylinder from an opening (27) provided at the other end in the axial direction of the case (22). It is inserted into the shaped part (22a),
The rotation transmission device according to claim 1 or 2, further comprising a seal member (44c) interposed between the outer diameter surface of the core (41) and the inner diameter surface of the case (22). Rotation around the axis of the steering shaft (4) is transmitted to the inner member (30) or the outer member (21) of the rotation transmission device according to claim 1 or 2, and the rotation transmission device is connected to the steering shaft (4). A steering device provided on the same axis as the axis of (4) or on a different axis from the axis of the steering shaft (4). Rotation about the axis of the steering shaft (4) is transmitted to the inner member (30) or the outer member (21) of the rotation transmission device according to claim 1 or 2,
A reaction force that applies a steering reaction force to the steering shaft (4), comprising a steering actuator (2) that changes the orientation of the steering member (3, 3) based on rotation of the steering shaft (4) around an axis. A steering device comprising a motor (6) between the steering shaft (4) and the inner member (30) or the outer member (21). Rotation about the axis of the steering shaft (4) is transmitted to the inner member (30) or the outer member (21) of the rotation transmission device according to claim 1 or 2, and rotation about the axis of the steering shaft (4) is transmitted to the inner member (30) or the outer member (21). Transportation equipment equipped with a steering device including a steering actuator (2) that changes the direction of steering members (3, 3) based on rotation.

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