JP2016179736A - Actuator for electric steering column device and electric steering column device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a driving force of an electric steering column device and achieve compactification of a driving mechanism.SOLUTION: An actuator for an electric steering column device drives at least one of a telescopic mechanism, which moves a steering shaft of the electric steering column device in an axial direction, and a tilt mechanism which moves the steering shaft in a vertical direction on a plane including the steering shaft. The actuator for the electric steering column device includes: a motor 10 which drives the telescopic mechanism or the tilt mechanism; and a rotor speed reduction device 20 which is coaxially connected with a motor shaft 10a of the motor 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an actuator for an electric steering column device for a vehicle, and an electric steering column device employing the actuator.

  By electrically moving the steering shaft in the direction of the axis of rotation or moving it up and down within the plane including this steering shaft, the steering position is adjusted to the optimal position according to the physique and driving posture of the driver. An electric steering column device may be employed. As this electric steering column device, for example, as shown in Patent Document 1, the rotation of a tilting motor is decelerated through a speed reduction mechanism including a worm gear, and is output as a linear motion of a tilt driving force transmission member by a feed screw mechanism. Some have a drive mechanism and a telescopic drive mechanism that decelerates the rotation of the telescopic motor through a reduction mechanism composed of a worm gear and outputs it as a linear motion of a telescopic drive force transmission member by a feed screw mechanism (this book) (See paragraphs 0007 of the literature, FIGS. 1 and 4).

  When this electric steering column device is used, by driving the tilt drive mechanism, the tilt driving force transmission projection moves in a direction perpendicular to the axial direction of the steering shaft, and the steering can be moved in the vertical direction. By driving the telescopic driving mechanism, the telescopic driving force transmission protrusion moves along the axial direction of the steering shaft, and the steering can be moved in the axial direction (see FIG. 5 of this document).

JP 2005-31826 A

  In the configuration described in Patent Document 1, the rotation of the tilting motor and the telescopic motor is transmitted to the driving force transmission member via the worm gear. The worm gear is transmitted to the motor shaft of the motor and the driving force transmission member. Since the output shaft cannot be arranged coaxially, the motor must be placed horizontally with respect to the output shaft. For this reason, there existed a problem which requires a large space for installation. However, in order for the driver to drive smoothly, it is necessary to secure sufficient space at the foot, so it is not easy to increase the capacity of the motor, and driving for stably driving the drive mechanism There are also problems that the securing of force is insufficient and the degree of freedom of the layout of the drive mechanism is limited.

  Therefore, an object of the present invention is to make the drive mechanism compact while ensuring the drive force of the electric steering column device.

  In order to solve this problem, in the present invention, at least one of a telescopic mechanism that moves the steering shaft of the electric steering column device in the axial direction or a tilt mechanism that moves the steering shaft in the vertical direction within the plane including the steering shaft is driven. An electric steering column device actuator comprising: a motor for driving the telescopic mechanism or tilt mechanism; and a roller speed reducer connected coaxially to a motor shaft of the motor. An actuator was constructed.

  In this way, by connecting the motor shaft of the motor and the output shaft that transmits the output from the roller reducer coaxially, there is no need to place the motor laterally with respect to the output shaft, and the degree of freedom in the layout of the drive mechanism Improvement and compactness can be achieved. In addition, since it is not necessary to place the motor horizontally, it is easy to increase the capacity of the motor, and sufficient torque for driving the electric steering device can be ensured. In addition, the roller reducer can have a high reduction ratio as compared with the worm gear and has excellent power transmission efficiency, so that the rotational force of the motor can be efficiently transmitted to the electric steering column device.

  In the above configuration, the roller speed reducer includes an eccentric disk provided on the motor shaft, a bearing fitted on the outer diameter side of the eccentric disk, and the outer ring on the outer diameter side of the outer ring of the bearing. An internal gear having internal teeth formed on an inner peripheral surface thereof, a plurality of reduction gear rolling elements arranged at equal intervals in the circumferential direction between the outer ring and the internal gear, and the deceleration It is preferable to have a configuration including a reduction gear holder that holds the rolling element.

  In each of the above configurations, a reverse input blocking clutch that blocks transmission of reverse input from the telescopic mechanism or the tilt mechanism to the motor side may be provided coaxially with the roller speed reducer. Thus, by providing the reverse input cutoff clutch, the electric steering column device can be smoothly driven by the driving force of the motor, while the driver applies a force in the axial direction or the vertical direction to the steering wheel. The force can be prevented from being transmitted to the motor.

  In the configuration provided with the reverse input shut-off clutch, the reverse input shut-off clutch is formed on a part of the outer peripheral surface at a predetermined angular interval, and the distance from the shaft center to the surface is relatively shorter than other places. An output shaft having a cam surface formed thereon, an outer diameter side of the output shaft, a holding member provided coaxially with the output shaft, and interposed between the output shaft and the holding member. A clutch rolling element and a pocket are formed at the same angular interval as the cam surface, and two clutch rolling elements are held in the pocket, and a fitting hole extending in the circumferential direction is formed at a position different from the pocket. A clutch holder that rotates around the shaft as the reducer holder rotates, and a switch pin that protrudes radially outward from the outer peripheral surface of the output shaft and has a tip fitted into the fitting hole. In the pocket Provided interposed between the lifting been two of the clutch rolling members, preferably in the configuration and a biasing member for biasing the respective clutch rolling elements in opposite directions.

  The actuator for an electric steering column apparatus according to each of the above configurations is suitable for an electric steering column apparatus.

  In the present invention, in the actuator for the electric steering column apparatus that drives at least one of the telescopic mechanism that moves the steering shaft of the electric steering column apparatus in the axial direction or the tilt mechanism that moves the steering shaft in the vertical direction within the plane including the steering shaft. An actuator for an electric steering column apparatus comprising: a motor that drives the telescopic mechanism or the tilt mechanism; and a roller speed reducer that is coaxially connected to the motor shaft of the motor.

  In this way, by connecting the motor shaft of the motor and the output shaft of the roller reducer coaxially, there is no need to place the motor horizontally with respect to the output shaft, improving the flexibility of the layout of the drive mechanism and making it compact. Can be planned. In addition, since it is not necessary to place the motor horizontally, it is easy to increase the capacity of the motor, and sufficient torque for driving the electric steering device can be ensured. In addition, since the roller speed reducer is superior in power transmission efficiency compared to the worm gear, the rotational force of the motor can be efficiently transmitted to the electric steering column device.

1 shows a first embodiment (applied to a drive mechanism of a telescopic mechanism) of an actuator for an electric steering column device according to the present invention, wherein (a) is a longitudinal sectional view, and (b) is a line bb in FIG. Sectional view along 1 is a longitudinal sectional view of a first embodiment of an actuator for an electric steering column device according to the present invention (applied to a drive mechanism of a tilt mechanism). 1 is a longitudinal sectional view showing a main part of the roller speed reducer shown in FIG. 1 is a longitudinal sectional view showing a configuration in which the motor has a large diameter and is thinned in the actuator for the electric steering column device shown in FIG. FIG. 2 is a longitudinal sectional view showing a configuration in which the motor is enlarged and thinned in the actuator for the electric steering column device shown in FIG. 2 shows a second embodiment (applied to a drive mechanism of a telescopic mechanism) of an actuator for an electric steering column apparatus according to the present invention, wherein (a) is a longitudinal sectional view, and (b) is a line bb in FIG. (C) is a cross-sectional view taken along the line cc in FIG. It is a longitudinal cross-sectional view which shows the principal part of the reverse input interruption | blocking clutch shown in FIG.6 (c), Comprising: (a) is a state in which the rotational force is not acting on a clutch holder, (b) is a rotational force on a clutch holder. (C) is a state where the clutch cage and the output shaft are rotated in the same direction.

  A first embodiment of an actuator for an electric steering column apparatus according to the present invention is shown in FIGS. The actuator for the electric steering column device is for driving a telescopic mechanism for moving the steering shaft of the electric steering column device in the axial direction and a tilt mechanism for moving the steering shaft in the vertical direction within the plane including the steering shaft. FIG. 1 shows an application example of a telescopic mechanism of an electric steering column device to a drive mechanism, and FIG. 2 shows an application example of a tilt mechanism of the electric steering column device to a drive mechanism.

  The actuator for the electric steering column device includes a motor 10 that drives a telescopic mechanism or a tilt mechanism and a roller speed reducer 20 that is coaxially connected to a motor shaft 10a of the motor 10 as main components.

  The roller speed reducer 20 includes an eccentric disc 21 provided on the motor shaft 10 a, an eccentric bearing 22 and support bearings 23 a and 23 b fitted on the outer diameter side of the eccentric disc 21, and an outer ring 22 a of the eccentric bearing 22. An internal gear 24 disposed at a predetermined interval from the outer ring 22a on the outer diameter side, a plurality of reduction gear rolling elements 25 disposed at equal intervals in the circumferential direction between the outer ring 22a and the internal gear 24, and the deceleration A reduction gear holder 26 that holds the rolling element 25, a support bearing 23 c that supports the reduction gear holder 26, and a housing 27 (27 a and 27 b) that are divided into two in the axial direction for storing them. The divided housings 27 a and 27 b are fastened with bolts 28.

  The outer diameter of the eccentric disc 21 changes in three stages in the axial direction, and the outer peripheral edge of the central step portion of the three stages is relative to the eccentric rotation shaft 21 a formed on the eccentric disc 21. Eccentric. On the other hand, the outer peripheral edges of the two adjacent steps at the center are concentric with the eccentric rotation shaft 21a. The eccentric bearing 22 is fitted in the central step, while the support bearings 23a and 23b are fitted in both adjacent steps in the center. Of the support bearings 23a and 23b, one support bearing 23a is provided so as to be interposed between the housing 27a, while the other support bearing 23b is provided between the reducer cage 26 and the other support bearing 23b. Is provided. A support bearing 23c is interposed between the reduction gear retainer 26 and the housing 27b.

  The motor shaft 10a of the motor 10 is fitted into the eccentric rotation shaft 21a. In FIG. 1 (b), the center of gravity of the eccentric disc 21 is located slightly above the motor shaft 10a. An inner ring 22 b of the eccentric bearing 22 is fitted on the outer edge side of the eccentric disc 21. An outer ring 22a is provided on the outer diameter side of the inner ring 22b, and rolling elements 22d held by a retainer 22c are provided at predetermined intervals between the inner ring 22b and the outer ring 22a. On the outer diameter side of the outer ring 22a, there is provided an internal gear 24 in which internal teeth 24a are formed at predetermined intervals in the circumferential direction. In this configuration, the internal gear 24 is configured as a separate member from the housing 27 (27a, 27b) of the roller speed reducer 20, but the internal gear 24 and the housing 27 (27a, 27b) are configured integrally. It can also be set as an aspect. The motor shaft 10 a is an input shaft to the roller reducer 20, while the reducer holder 26 functions as an output shaft of the roller reducer 20. A shaft body 29 for transmitting a driving force to the telescopic mechanism or the tilt mechanism is coaxially inserted into the reduction gear holder 26.

  In this configuration, 51 internal teeth 24 a are formed in the circumferential direction, and 25 reduction gear rolling elements 25 are provided between the outer ring 22 a and the internal gear 24. As shown in FIG. 1B, when the center of gravity of the eccentric disk 21 is located on the upper side, the eccentric bearing 22 is also eccentric upward in the circumferential direction corresponding to the amount of eccentricity of the eccentric disk 21. Of the reduction gear rolling elements 25 arranged at a predetermined interval, as shown in FIG. 3, the reduction gear rolling element 25 located just above the eccentric bearing 22 is in a state of being completely engaged with the inner teeth 24a. As the eccentric bearing 22 moves downward from the upper side in the circumferential direction, the meshing displacement of the reduction gear rolling element 25 and the inner teeth 24a increases. Are not engaged.

  Since the roller speed reducer 20 has higher power transmission efficiency than the worm gear, the rotation of the motor shaft 10a can be efficiently transmitted to the telescopic mechanism or the tilt mechanism, and the steering position can be adjusted smoothly. it can. Moreover, since the motor shaft 10a, the roller speed reducer 20, and the shaft body 29 of the motor 10 can be arranged on the same shaft, the motor is placed horizontally with respect to the shaft body 29 as in the case where a worm gear is employed (FIG. ) And the motor M indicated by imaginary lines in FIG. 2), and the degree of freedom of the layout of the entire apparatus can be improved. Therefore, a sufficient space necessary for safe driving is secured at the driver's feet, and safety improvement such as avoiding a secondary collision with the driver at the time of a collision can be achieved.

  When the motor 10 is driven and the motor shaft 10a is rotated around the axis, the eccentric disk 21 rotates around the eccentric rotation shaft 21a. As the eccentric disk 21 rotates, the position at which the reduction gear rolling element 25 and the inner teeth 24a are completely meshed sequentially moves in the circumferential direction from the upper side of the eccentric bearing 22 shown in FIG. Then, while the motor shaft 10a makes one rotation in one direction, the reduction gear rolling element 25 moves in the circumferential direction by one inner tooth 24a, and the reduction gear holder 26 holding the reduction gear rolling element 25 rotates around the axis. Is decelerated with respect to the rotation of the motor shaft 10a. For example, in the case of the roller speed reducer 20 shown in FIG. 1B, the reduction ratio is 1:50. This reduction ratio can be appropriately changed by changing the number of teeth of the inner teeth 24a, the number of reduction gear rolling elements 25, the degree of eccentricity, and the like.

  As shown in FIGS. 1A and 2, in the configuration in which the motor 10 is disposed coaxially with the roller speed reducer 20, FIG. 4 (when applied to a driving mechanism of a telescopic mechanism) and FIG. As shown in (when applied to a drive mechanism), the capacity of the motor 10 can be increased by reducing the axial length of the motor 10 and increasing the diameter to the diameter of the roller speed reducer 20. When the motor 10 is arranged coaxially with the roller speed reducer 20, it becomes possible to arrange the roller speed reducer 20 and the motor 10 integrally, smooth adjustment of the steering position by increasing the capacity of the motor 10, and compactness. Both securing can be achieved.

  6 (a) to 6 (c) show a second embodiment of the actuator for an electric steering column device according to the present invention. This actuator for an electric steering column device is obtained by adding a reverse input cutoff clutch 30 to the roller speed reducer 20 of the electric steering column device according to the first embodiment.

  The reverse input cutoff clutch 30 is interposed between the output shaft 31, a holding member 32 provided coaxially with the output shaft 31 on the outer diameter side of the output shaft 31, and the output shaft 31 and the holding member 32. A clutch rolling element 33 provided, a clutch retainer 34 that holds the clutch rolling element 33, a switch pin 35, and an urging member 36 are provided. In this embodiment, the holding member 32 and the housing 27b are configured as separate members, but the holding member 32 and the housing 27b may be configured as a single unit.

  The output shaft 31 is formed on a part of the outer peripheral surface of a flat surface having a relatively short distance from the shaft center to the surface at a predetermined angular interval (in this configuration, every 60 degrees in the circumferential direction). A cam surface 37 is formed. The output shaft 31 is formed with an insertion hole 38 penetrating from the center side to the outer diameter surface.

  The clutch holder 34 is configured integrally with the speed reducer holder 26 of the roller speed reducer 20. Pockets 39 are formed in the clutch holder 34 at the same angular interval (that is, every 60 degrees) as the angular interval of the cam surface 37 formed on the output shaft 31. Further, a fitting hole 40 is formed at a position different from the pocket 39. The circumferential length of the fitting hole 40 is slightly longer than the diameter of the switch pin 35. When the switch pin 35 is inserted into the fitting hole 40 as will be described later, the switch is inserted in the fitting hole 40. A play is provided so that the pin 35 can be moved relatively in the circumferential direction.

  In each pocket 39, two clutch rolling elements 33 are held, and an urging member 36 is provided between the clutch rolling elements 33 and 33. The urging member 36 urges the clutch rolling elements 33 and 33 in opposite directions. The clutch rolling elements 33 and 33 are pressed against the circumferential wall surface of the pocket 39 by the urging force from the urging member 36. The switch pin 35 is inserted into an insertion hole 38 formed in the output shaft 31, and a tip portion protruding from the insertion hole 38 is fitted into a fitting hole 40 formed in the clutch holder 34. Yes.

  The operation of the reverse input cutoff clutch 30 will be described with reference to FIGS. When the reducer holder 26 of the roller reducer 20 rotates around the axis from the state shown in FIG. 5A, the clutch holder 34 integrated with the reducer holder 26 is fitted with the switch pin 35. It idles within the range of the play (see this figure (a)) formed between the joint holes 40. Then, the play disappears, and the switch pin 35 comes into contact with the inner surface on one end side of the fitting hole 40 (see FIG. 4B). At this time, the position of the pocket 39 formed in the clutch holder 34 and the position of the cam surface 37 formed on the output shaft 31 are shifted by the idling angle, whereby the two clutch rolling elements held in the pocket 39 are obtained. 33 and 33 (33a, 33b), the gap between the inner surface of the holding member 32 and the cam surface 37 is narrowed on the clutch rolling element 33a side on the rotation front side. Along with this, the clutch rolling element 33 a is engaged between the holding member 32 and the cam surface 37.

  At this time, the inner surface on one end side of the fitting hole 40 formed in the clutch cage 34 presses the switch pin 35 in one direction, whereby the output shaft 31 rotates in this one direction. Thereby, the clearance gap between the internal peripheral surface of the holding member 32 and the cam surface 37 spreads, the engagement state of the clutch rolling element 33a between the holding member 32 and the cam surface 37 reduces, and this figure ( As shown in c), the output shaft 31 and the clutch cage 34 rotate smoothly in the same direction. Note that when the clutch retainer 34 rotates in the direction opposite to the one direction, the other clutch rolling element 33b is different in that it is engaged, but the operation of the reverse input cutoff clutch 30 has been described above. It is the same.

  On the other hand, when the rotational force in the reverse direction acts on the output shaft 31 when the clutch retainer 34 tries to rotate in one direction around the shaft, the clutch retainer 34 is connected to the switch pin 35 in the same manner as described above. It idles within the range of play formed between the fitting holes 40. Then, as shown in this figure (b), the play is lost and the switch pin 35 comes into contact with one end of the fitting hole 40. At this time, the position of the pocket 39 formed in the clutch holder 34 and the position of the cam surface 37 formed on the output shaft 31 are shifted by the idling angle, and the clutch rolling element is interposed between the holding member 32 and the cam surface 37. 33a is engaged.

  At this time, if a reverse rotational force acts on the output shaft 31, even if the inner surface on one end side of the fitting hole 40 formed in the clutch retainer 34 presses the switch pin 35 in one direction, Due to the pressing, the output shaft 31 cannot rotate in this one direction. For this reason, the clutch rolling element 33 a can be rotated by both the rotational force in one direction of the clutch cage 34 and the rotational force in the reverse direction of the output shaft 31. The engagement is further strengthened, and the relative rotation in the opposite direction around the axis between the output shaft 31 and the clutch retainer 34 is locked. Note that when the clutch retainer 34 rotates in the direction opposite to the one direction, the other clutch rolling element 33b is different in that it is engaged, but the operation of the reverse input cutoff clutch 30 has been described above. It is the same.

  As described above, by providing the reverse input cutoff clutch 30 in addition to the roller speed reducer 20, it is possible to prevent a reverse rotational force from acting on the motor from the output shaft side (steering side).

  The above-described electric steering column device is merely an example, and as long as the problem of the present invention that the drive mechanism can be made compact while securing the driving force of the electric steering column device can be solved, each component It is also possible to change the shape and arrangement of the components or add additional parts. For example, it can also be set as the structure which connected the some roller reduction gear 20 coaxially, or used the roller reduction gear 20 and the other kind of reduction gear together.

DESCRIPTION OF SYMBOLS 10 Motor 10a Motor shaft 20 Roller speed reducer 21 Eccentric disk 21a Eccentric rotating shaft 22 Eccentric bearing 22a Outer ring 22b Inner ring 22c Cage 22d Rolling elements 23a, 23b, 23c Support bearing 24 Internal gear 24a Internal teeth 25 Reducer rolling element 26 Deceleration Machine retainer 27 (27a, 27b) Housing 28 Bolt 29 Shaft body 30 Reverse input cutoff clutch 31 Output shaft 32 Holding member 33 (33a, 33b) Clutch rolling element 34 Clutch retainer 35 Switch pin 36 Energizing member 37 Cam surface 38 Insertion hole 39 Pocket 40 Fitting hole

Claims (5)

In an actuator for an electric steering column device that drives at least one of a telescopic mechanism that moves the steering shaft of the electric steering column device in the axial direction, or a tilt mechanism that moves the steering shaft in the vertical direction within the plane including the steering shaft,
A motor (10) for driving the telescopic mechanism or the tilt mechanism;
A roller speed reducer (20) connected coaxially to the motor shaft (10a) of the motor (10);
An actuator for an electric steering column device comprising: The roller reducer (20)
An eccentric disk (21) provided on the motor shaft (10a);
An eccentric bearing (22) fitted on the outer diameter side of the eccentric disc (21);
An internal gear (24) having a predetermined distance from the outer ring (22a) on the outer diameter side of the outer ring (22a) of the eccentric bearing (22) and having inner teeth (24a) formed on the inner peripheral surface;
A plurality of reduction gear rolling elements (25) disposed at equal intervals in the circumferential direction between the outer ring (22a) and the internal gear (24);
A reduction gear holder (26) for holding the reduction gear rolling element (25);
The actuator for an electric steering column apparatus according to claim 1, comprising:   A reverse input cutoff clutch (30) for blocking transmission of reverse input from the telescopic mechanism or the tilt mechanism to the motor (10) side is provided coaxially with the roller speed reducer (20). Item 3. The actuator for an electric steering column device according to Item 1 or 2. The reverse input cutoff clutch (30) is
An output shaft (31) in which a cam surface (37) made of a flat surface is formed on a part of the outer peripheral surface at a predetermined angular interval and the distance from the shaft center to the surface is relatively shorter than other places;
A holding member (32) provided coaxially with the output shaft (31) on the outer diameter side of the output shaft (31);
A clutch rolling element (33) provided between the output shaft (31) and the holding member (32);
Pockets (39) are formed at the same angular intervals as the cam surface (37), and two clutch rolling elements (33) are held in the pockets (39) at a time, and are different from the pockets (39). A clutch holder (34) that is formed with a fitting hole (40) extending in the circumferential direction and rotates about an axis in accordance with the rotation of the speed reducer holder (26);
A switch pin (35) provided so as to protrude radially outward from the outer peripheral surface of the output shaft (31) and having a tip fitted into the fitting hole (40);
A biasing member provided between the two clutch rolling elements (33a, 33b) held in the pocket (39) and biasing the respective clutch rolling elements (33a, 33b) in opposite directions. (36)
The actuator for an electric steering column device according to claim 3, comprising:   An electric steering column apparatus, wherein at least one of a telescopic mechanism and a tilt mechanism is driven by the actuator for an electric steering column apparatus according to any one of claims 1 to 4.

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