JP2018158692A - Actuator for steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator for a steering device which achieves improvement of steering operability.SOLUTION: An actuator 1 for a steering device includes: a steering shaft 2; a transmission mechanism 41 which transmits rotation of the steering shaft to turning wheels; a piston 38 provided at the transmission mechanism; and a pair of pressure chambers 46, 47 which generate force for moving the piston and is provided between a fluid pressure power steering device which applies steering force to the turning wheels in conjunction with the movement of the piston and a steering wheel. The actuator 1 has: a housing having a motor part housing part 8 and a speed reducer housing part 20; a motor part 3 having a motor rotor 3a which is provided in the motor part housing part and is formed into a cylindrical shape so as to enclose the steering shaft, and a stator 3b provided at an outer periphery of the motor rotor; and a speed reducer 19 which is provided in the speed reducer housing part, is formed into an annular shape so as to enclose the steering shaft, and transmits rotational force of the motor part to the steering shaft.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a structure of an actuator for a vehicle steering apparatus.

A conventional actuator for a steering device discloses a technique for rotating a control valve for switching a hydraulic pressure supply destination with an electric motor.
(For example, patent document 1).

JP2015-145184A

However, since the actuator for the steering device directly rotates the control valve with an electric motor, a large torque cannot be applied to the steering shaft, and there is a need to improve the steering operability. .
An object of the present invention is to provide an actuator for a steering apparatus with improved steering operability.

  In order to achieve the above object, in the actuator for a steering device according to the present invention, the rotational force of the electric motor is transmitted to the steering shaft via the speed reducer.

  Therefore, in the actuator for a steering device of the present invention, a relatively large torque can be applied to the steering shaft, and the steering operability can be improved.

FIG. 3 is a longitudinal sectional view of the steering device actuator according to the first embodiment. 1 is an exploded isometric view of a wave gear reducer 19 of Embodiment 1. FIG. It is the schematic showing the meshing state of the flexspline 19c and the circular spline 19b of Example 1. FIG. FIG. 6 is a longitudinal sectional view of a steering device actuator according to a second embodiment. FIG. 6 is a longitudinal sectional view of a steering device actuator according to a third embodiment. FIG. 6 is a longitudinal sectional view of a steering device actuator according to a fourth embodiment. FIG. 10 is a longitudinal sectional view of an actuator for a steering device according to a fifth embodiment. FIG. 10 is a longitudinal sectional view of a steering device actuator according to a sixth embodiment. FIG. 10 is a longitudinal sectional view of an actuator for a steering device according to a seventh embodiment. FIG. 10 is a longitudinal sectional view of a steering device actuator according to an eighth embodiment.

  Hereinafter, a mode for realizing an actuator for a steering device of the present invention will be described based on an embodiment shown in the drawings.

[Example 1]
FIG. 1 is a longitudinal sectional view of an actuator for a steering device according to a first embodiment.
The steering device actuator 1 is mounted on a vehicle and used for steering assist and automatic steering. Hereinafter, the X axis is provided in the direction in which the input shaft 2 extends, and the side of the steering wheel (the right side in FIG. 1) is the positive direction.

  The steering device actuator 1 is provided on the outer periphery of an input shaft 2 as an input shaft portion that constitutes a steering shaft and an intermediate shaft 5 as an intermediate shaft portion. The input shaft 2 is coupled to one end of a torsion bar 6 disposed in the hollow portion 2a via a pin 6a, and the other end of the torsion bar 6 enters a recess 5a formed in the intermediate shaft 5, The input shaft 2 and the intermediate shaft 5 are coupled to each other via the torsion bar 6 so as to be relatively rotatable. A bearing 7 is disposed between the input shaft 2 and the intermediate shaft 5. A serration 140 that can be connected to the steering shaft on the steering wheel side is formed at the end of the input shaft 2 in the positive direction of the X-axis.

The electric motor 3 as a motor unit is provided on the outer periphery of the intermediate shaft 5, and is a motor stator that is a rotating motor rotor 3 a and a coil winding provided on the outer periphery of the motor rotor 3 a and fixed to the intermediate member 8 a of the motor housing 8. 3b.
The electric motor 3 is accommodated in a motor housing 8 as a motor portion accommodating portion constituted by an intermediate member 8a and a ring member 8b as a first housing portion.
The end of the intermediate member 8a on the X-axis negative direction side is provided with a seal 16 inside the X-axis positive direction end of the ring member 8b, and is fixed with a bolt (not shown).
The ring-shaped portion 8 a ′ extending in the X-axis positive direction of the intermediate member 8 a enters the inside of the X-axis negative direction end of the lid member 8 c including the seal 10 and is fixed by the bolt 11.
The motor rotor 3a is rotatably supported by the intermediate member 8a and the ring member 8b by bearings 13 and 14 on the left and right in the X-axis direction via a cylindrical sleeve member 3a '.

An IC Hall type torque sensor 4 as a torque sensor portion fixed to the input shaft 2 is accommodated in a space formed by the ring-shaped portion 8a ′ extending in the X-axis positive direction of the intermediate member 8a and the lid member 8c. Has been. The inner periphery of the end of the lid member 8c on the X axis positive direction side supports the input shaft 2 via the bearing 12, and is sealed with a seal 13a.
Further, the end of the torque sensor 4 on the X axis negative direction side is provided integrally with the inner periphery of the motor rotor 3a, and is a cylindrical sleeve member 3a ′ rotatably supported on the intermediate shaft 5 via a bearing 7a. Are disposed so as to enter into the recess 15 formed on the inner periphery of the inner surface of the inner surface of the inner shaft 5 and overlap with the intermediate shaft 5 in the X-axis direction.

Further, a resolver 17 as a rotation angle sensor of the electric motor 3 is disposed on the outer periphery of the cylindrical sleeve member 3a ′ on the X-axis negative direction side inside the ring member 8b on the X-axis negative direction side.
The resolver 17 is provided on the outer periphery in the radial direction of the sensor rotor 17a and the sensor rotor 17a as a sensor rotor portion provided on the outer periphery of the end portion of the cylindrical sleeve member 3a ′ of the motor rotor 3a in the X-axis negative direction. A sensor stator 17b as a sensor stator portion fixed to a partition wall 8b ′ extending radially inward by a bolt 18;

Further on the X-axis negative direction side of the resolver 17, a wave gear reducer 19 as a reducer is disposed on the outer periphery of the intermediate shaft 5 so as to decelerate the rotation of the electric motor 3 and transmit it to the intermediate shaft 5. .
The wave gear reducer 19 includes a wave generator 19a as a wave generator in which a thin ball bearing is combined with the outer periphery of an elliptical cam that rotates integrally with the sleeve member 3a ′ of the motor rotor 3, and an inner tooth on the inner periphery. It has a rigid ring shape and is fixed to a housing member 20 as a ring-shaped second housing portion constituting a reduction gear housing portion by bolts 21, an outer peripheral surface thereof, an inner periphery of the ring member 8 b and the ring-shaped housing member 20 A circular spline 19b as a rigid internal gear arranged with a gap fitted between the surfaces and a thin cup-like shape having a cylindrical portion 23a and a bottom portion 23b, and having elasticity, and connecting to the intermediate shaft 5 As a part, inside the cylindrical part 23a, the bottom part 23b is fixed to a sleeve 62 that rotates integrally with the intermediate shaft 5 with a bolt 22, and rotates integrally with the intermediate shaft 5. And a flex spline 19c as an annular flexible external gear.
The ring member 8b and the housing member 20 are fixed by bolts 21a via a seal 130.

FIG. 2 is an exploded isometric view of the wave gear reducer 19 of the first embodiment.
The structure of the wave gear reducer 19 will be described in detail.
The circular spline 19b is a rigid annular member having a plurality of internal teeth 190b on the inner periphery.
A flexspline 19c as an annular flexible external gear is disposed on the inner diameter side of the circular spline 19b. The flex spline 19c has outer teeth 190c that mesh with the inner teeth 190b on the outer peripheral surface. The flex spline 19c is a thin-walled cylindrical member that is made of a metal material and has a bottom portion and can be deformed flexibly. The number of external teeth 190c of the flexspline 19c is two fewer than the number of internal teeth 190b of the circular spline 19b. An insertion hole 192c through which the intermediate shaft 5 passes is formed on the inner periphery of the flange portion 191c formed at the bottom of the flex spline 19c. Therefore, since the flex spline 19c is coupled to the sleeve 62 of the intermediate shaft 5 and the flange portion 191c by the bolt 22, the inner periphery of the insertion hole 192c can be supported by the intermediate shaft 5, and the rigidity of the bottom portion of the flex spline 19c is ensured. it can.
The wave generator 19a is formed in an oval shape, and its outer peripheral surface slides along the inner peripheral surface of the flexspline 19c. At the center of the wave generation plug 190a, a sleeve member 3a 'of the motor rotor 3 is fixed by press fitting. The wave generator 19a includes a wave generation plug 190a and a deep groove ball bearing 191a. The wave generation plug 190a has an elliptical shape. The deep groove ball bearing 191a has a flexible thin inner and outer ring that allows relative rotation between the outer periphery of the wave generating plug 190a and the inner periphery of the flex spline 19c.

FIG. 3 is a schematic diagram illustrating the meshing state of the flex spline 19c and the circular spline 19b according to the first embodiment. Since the wave generating plug 190a having an elliptical outer shape is fitted into the inner ring of the deep groove ball bearing 191a to follow the elliptical shape, the outer shape of the wave generator 19a is also elliptical. Further, by fitting the wave generator 19a to the inner diameter of the flexspline 19c, the flexspline 19c whose initial state is circular is also deformed into an elliptical shape. Since the flex spline 19c deflected into an ellipse has two teeth fewer than the circular spline 19b, the flex spline 19c meshes with the tooth pitch on the major axis of the ellipse, and the tooth pitch matches on the minor axis of the ellipse. Since 19c is bent in the axial direction, teeth do not overlap and do not interfere. For this reason, the flexspline 19c and the circular spline 19b having the even number of teeth difference can be engaged with each other as in the engagement state shown in FIG.
The teeth of the flex spline 19c are flexible, but the flange 191c cannot be deformed from a circular shape in order to take out the output and is directly fastened to the intermediate shaft 5, so that the thin-walled cylinder starts from the flange 191c. It becomes a shape which spreads into an elliptical shape toward the opening end. That is, the rotation decelerated from the rotation of the electric motor 3 of the flexspline 19c extracted from the deformation motion near the opening end can be transmitted from the flange portion 191c to the intermediate shaft 5.
As described above, since the annular wave gear reducer 19 and the electric motor 3 as the reduction mechanism are arranged in the X-axis direction and arranged around the intermediate shaft 5 as the steering shaft, it is possible to suppress an increase in the radial dimension. it can.
The annular wave gear reducer 19 has a volume equal to or less than 重量 and a weight equal to or less than ½ that of other reducers, and can provide the same torque capacity and reduction ratio, and 1 / 30-1 / It has a high reduction ratio of 320.

Next, the structure of the hydraulic power steering apparatus 100 will be described with reference to FIG.
A recess 24 is formed at the end of the intermediate shaft 5 on the X axis negative direction side, and the end of the torsion bar 25 on the X axis positive direction side is inserted into the recess 24. The intermediate shaft 5 and the torsion bar 25 are fixed by pins 26. The end of the torsion bar 25 on the X axis negative direction side is accommodated in a hollow torsion bar accommodating portion 27 a formed on a screw shaft 27 as an output shaft, and is connected to the screw shaft 27 via a pin 33. The intermediate shaft 5 is rotatably supported by the bearing 32 with respect to the screw shaft 27. The screw shaft 27, the intermediate shaft 5 and the input shaft 2 as the output shaft portion constitute a steering shaft. A valve body 28 is formed integrally with the screw shaft 27 on the positive side of the screw shaft 27 in the X-axis direction. The valve body 28 is rotatably supported by a valve housing 29 via a ball bearing 30. The valve housing 29 is integrally coupled to the steering housing 31 by a bolt (not shown) at the end on the X axis positive direction side of the steering housing 31. In order to couple with the housing member 20, the valve housing 29 is provided with an internal thread portion 35 into which a bolt 34 is screwed and a lock nut accommodation hole 20 a that opens. A ball bearing 30 is inserted into the X axis negative direction end of the lock nut accommodation hole 20a, and a lock having a seal 142 for restricting movement of the outer race 30a of the ball bearing 30 in the X axis positive direction on the X axis positive direction side. A nut 36 is provided. The female thread portion 35 is provided so as to overlap the lock nut 36 in the X-axis direction.

A piston 38 is provided on the outer periphery of the screw shaft 27 via a ball nut 37 so as to be movable in the X-axis direction. The piston 38 is accommodated in a cylindrical cylinder portion 39 formed in the steering housing 31. The end of the cylinder portion 39 on the X axis positive direction side is closed by a valve housing 29 including a seal 143, and the X axis negative direction side end is closed by a bottom portion 40. The sector gear 41 is accommodated in a gear chamber 42 formed in the steering housing 31 and in a direction orthogonal to the cylinder portion 39. The sector gear 41 meshes with the rack teeth 44 of the rack 43 formed on the outer periphery of the piston 38. The sector gear 41 is connected to a pitman arm connected to a steered wheel (not shown). The sector gear 41 and the rack teeth 44 of the rack 43 constitute a transmission mechanism that transmits the rotation of the steering shaft to the steered wheels. A piston seal 45 is attached to the outer periphery of the piston 38. A cylinder portion 39 is divided into a first pressure chamber 46 and a second pressure chamber 47 by the piston seal 45 to constitute a power cylinder. The X-axis negative direction side from the piston seal 45 of the cylinder part 39 is the first pressure chamber 46, and the X-axis positive direction side and the gear chamber 42 are the second pressure chamber 47 from the piston seal 45 of the cylinder part 39.
A plurality of switching grooves 48 extending in the X-axis direction are provided on the outer periphery of the intermediate shaft 5 at predetermined intervals. A plurality of first axial grooves 50 and second axial grooves 51 extending in the X-axis direction are formed at predetermined intervals on the inner periphery of the rotor accommodating portion 49 of the valve body 28 facing the outer periphery of the intermediate shaft 5. . A suction side circumferential groove 52 and a first pressure chamber side circumferential groove 53 extending in the circumferential direction are formed on the inner circumferential surface of the valve housing 29 facing the outer circumference of the valve body 28 so as to be separated from each other in the X-axis direction. ing.

  The valve body 28 includes a first oil passage 54 that communicates the first axial groove 50 and the first pressure chamber side circumferential groove 53, and a second oil that communicates the second axial groove 51 and the second pressure chamber 47. A third oil passage 56 that connects the passage 55 and the inner periphery and the outer periphery of the valve body 28 is formed. The valve housing 29 is connected to a suction port 57 that is connected to an external oil pump, a fourth oil passage 58 that communicates the suction port 57 and the suction-side circumferential groove 52, and a first pressure chamber-side circumferential groove 53. A fifth oil passage 59 is formed. The oil passages are sealed with a plurality of seals 144 provided in the valve housing 29. The steering housing 31 is formed with a sixth oil passage 60 that communicates the fifth oil passage 59 and the first pressure chamber 46. The switching groove 48 of the intermediate shaft 5, the first axial groove 50 of the valve body 28, and the second axial groove 51 allow the working oil to be supplied from the oil pump by the relative rotation of the intermediate shaft 5 and the valve body 28. A control valve 61 that switches between the first pressure chamber 46 or the second pressure chamber 47 is formed.

Next, the operation of the hydraulic power steering apparatus 100 will be described.
(Steering assist and automatic steering action)
When the driver steers the steering wheel so that the piston 38 moves to the first pressure chamber 46 side (X-axis negative direction side), the steering torque is detected by the torque sensor 4, and electric driving is performed according to the detected steering torque. The motor 3 is rotationally driven, and the motor 3 is decelerated by the wave gear reducer 19 to rotationally drive the intermediate shaft 5, so that a relatively large torque can be applied, and the control valve 61 supplies hydraulic oil to the second pressure chamber 47. Is supplied. That is, the hydraulic oil discharged from the oil pump is the suction port 57 → the fourth oil passage 58 → the first axial groove 50 → the third oil passage 56 → the switching groove 48 → the second axial groove 51 → the second oil passage. 55 is supplied to the second pressure chamber 47. Since the pressure in the second pressure chamber 47 rises and an assist force that moves the piston 38 toward the first pressure chamber 46 acts by this pressure, the driver can steer the steering wheel with a light force.
On the other hand, when the driver steers the steering wheel so that the piston 38 moves to the second pressure chamber 47 side (X-axis positive direction side), the steering torque is detected by the torque sensor 4, and the detected steering torque is detected. The electric motor 3 is rotationally driven, and this is decelerated by the wave gear reducer 19 and the intermediate shaft 5 is rotationally driven. Therefore, a relatively large torque can be applied, and the control valve 61 allows the first pressure chamber 46 to enter the first pressure chamber 46. Hydraulic oil is supplied. That is, the hydraulic oil discharged from the oil pump is the suction port 57 → the fourth oil passage 58 → the first axial groove 50 → the third oil passage 56 → the switching groove 48 → the first axial groove 50 → the first oil passage. 54 → first pressure chamber side circumferential groove 53 → fifth oil passage 59 → sixth oil passage 60 and supplied to the first pressure chamber 46. Since the pressure in the first pressure chamber 46 rises and an assist force that moves the piston 38 toward the second pressure chamber 47 acts by this pressure, the driver can steer the steering wheel with a light force.
Further, the electric motor 3 is driven to rotate, and the wave gear is decelerated so that the piston 38 moves to the first pressure chamber 46 side (X-axis negative direction side) or the second pressure chamber 47 side (X-axis positive direction side). By decelerating by the machine 19 and controlling the rotation of the intermediate shaft 5, a relatively large torque can be applied, and even when the driver is not steering, the first pressure chamber 46 and the second pressure The piston 38 can be stroked by the pressure difference between the chambers 47. That is, by rotating the electric motor 3 according to the driving state of the vehicle, the turning angle of the steered wheels can be set to a desired angle without the driver's steering. Thereby, the automatic steering which controls a steered wheel automatically is realizable by rotationally driving the electric motor 3 according to the driving | running state of vehicles, such as a lane keep. Controlling the rotation of the intermediate shaft 5 includes generating motor torque so that the input shaft 2 does not rotate.

Next, the function and effect will be described.
The actuator for the steering device according to the first embodiment has the following effects.

(1) The electric motor 3 and the annular wave gear reducer 19 as a speed reduction mechanism are arranged in the X-axis direction and arranged around the intermediate shaft 5 as a steering shaft.
Therefore, an increase in the radial dimension around the steering shaft can be suppressed.
In addition, the rotational force of the electric motor 3 is transmitted to the intermediate shaft 5 as a steering shaft through an annular wave gear reducer 19 that is a reduction mechanism.
Therefore, a relatively large torque can be applied to the intermediate shaft 5 as the steering shaft, and the steering operability can be improved.

(2) A resolver 17 for detecting the rotation angle of the motor rotor 3a is disposed.
Therefore, the electric motor 3 can be driven and controlled based on the motor rotation angle information, and the electric motor can be controlled with high accuracy.

(3) The sensor rotor 17a is provided on the outer periphery of a cylindrical sleeve member 3a ′ provided on the inner periphery of the motor rotor 3a.
Therefore, operations such as formation and assembly of the connection portion of the sensor rotor 17a are easier than in the case where the sensor rotor 17a is provided on the motor rotor 3a.

(4) The input shaft 2 and the intermediate shaft 5 are connected to each other via a torsion bar so as to be relatively rotatable, and a torque sensor unit for detecting the relative rotation amount is further provided.
Therefore, motor control according to the steering torque can be performed, and the steering operability can be improved. Further, the IC Hall type torque sensor 4 as the torque sensor unit is provided separately from the resolver 17 as the motor rotation angle sensor for detecting the rotation angle of the motor rotor 3a, and therefore an annular wave gear reducer 19 as a reduction mechanism. The relative angle between the input shaft 2 and the intermediate shaft 5 can be detected without being affected by the reduction ratio.

(5) The end of the IC hall type torque sensor 4 on the negative side in the X-axis is in a recess 15 formed on the inner periphery of a cylindrical sleeve member 3a ′ provided integrally with the inner periphery of the motor rotor 3a. It is arranged so as to enter and overlap the electric motor 3.
Therefore, the axial dimension of the steering device actuator 1 can be suppressed.

(6) The IC Hall type torque sensor 4 as the torque sensor unit is provided on the input shaft 2 side of the electric motor 3 in the rotation axis direction of the steering shaft.
Therefore, since the radial dimension of the torque sensor 4 is generally smaller than that of the electric motor 3, the radial dimension on the input shaft 2 side, that is, the steering wheel side can be suppressed to be small. This is advantageous particularly in application to an integral type power steering apparatus mounted on a truck.

(7) The connecting portion of the flexspline 19c as the flexible external gear of the intermediate shaft 5 as the steering shaft and the annular wave gear reducer 19 as the speed reducer is inside the cylindrical portion 23a of the flexspline 19c. It was made to connect with the bottom part 23b.
Therefore, since the connecting portion is provided in the internal space of the flex spline 19c as a flexible external gear serving as a dead space, the size of the steering device actuator 1 can be suppressed.

(8) The circular spline 19b as a rigid internal gear has a rigid ring shape having internal teeth on the inner periphery, and is fixed to a housing member 20 as a ring-shaped second housing portion as a reduction gear housing portion by a bolt 21. The gap between the outer peripheral surface and the inner peripheral surface of the ring member 8b and the ring-shaped housing member 20 is fitted with a gap.
Accordingly, the positional accuracy of the housing such as the ring member 8b and the housing member 20 and the circular spline 19b can be increased, and the annular member connected to the intermediate shaft 5 that is pivotally supported by the housing such as the ring member 8b and the housing member 20 or the like. The coaxiality of the flex spline 19c as a flexible external gear and the circular spline 19b can be improved, and a smooth wave gear operation can be obtained.

[Example 2]
FIG. 4 is a longitudinal sectional view of the steering device actuator of the second embodiment.

  Since the configuration is the same as that of the first embodiment except that a resolver 110 as an angle sensor is disposed instead of the IC hall type torque sensor 4 as the torque sensor unit, the same components are denoted by the same reference numerals. The description of the same part is omitted.

The resolver 110 is configured by a sensor stator 110b fixed to a vertical wall 80a extending radially inward of the intermediate member 8a by a bolt 111 and a sensor rotor 110a fixed to the input shaft 2.
In the case of the second embodiment, the rotational speeds of the input shaft 2 provided with the resolver 110 and the motor rotor 3a provided with the resolver 17 serving as a motor rotation angle sensor differ by the reduction ratio of the wave gear reducer 19.
For this reason, the adjustment of the detection cycle of the resolver 110 and the detection cycle of the resolver 17, that is, the detection cycle per rotation of the motor rotor 3 a of the resolver 17 is reduced to the detection cycle per rotation of the input shaft 2 of the resolver 110. A value obtained by multiplying the reduction ratio of the machine 19 is used.

Therefore, the actuator for the steering device according to the second embodiment has the following functions and effects in addition to the same functions and effects as those of the first embodiment.
(1) By calculating the difference in phase between the output signals of the resolver 17 and the resolver 110 as the torsion amount of the torsion bar 6, calculation of the steering torque using the output signals of both the resolvers 17 and 110 is facilitated.

[Example 3]
FIG. 5 is a longitudinal sectional view of the steering device actuator of the third embodiment.

  Since the configuration is the same as that of the first embodiment except that the IC hall type torque sensor 4 as a torque sensor is not provided, the same components are denoted by the same reference numerals, and the description of the same portions is omitted.

  Since there is no torque sensor 4, the input shaft 2 and the intermediate shaft 5 are integrated as a steering shaft.

Next, the function and effect will be described.
The actuator for the steering device according to the third embodiment has the following effects.

(1) The electric motor 3 and the annular wave gear reducer 19 as a speed reduction mechanism are arranged in the X-axis direction and arranged around the intermediate shaft 5 as a steering shaft.
Therefore, an increase in the radial dimension around the steering shaft can be suppressed.
In addition, the rotational force of the electric motor 3 is transmitted to the intermediate shaft 5 as a steering shaft through an annular wave gear reducer 19 that is a reduction mechanism.
Therefore, a relatively large torque can be applied to the intermediate shaft 5 as the steering shaft, and the steering operability can be improved.

(2) A resolver 17 for detecting the rotation angle of the motor rotor 3a is disposed.
Therefore, the electric motor 3 can be driven and controlled based on the motor rotation angle information, and the electric motor can be controlled with high accuracy.

(3) The sensor rotor 17a is provided on the outer periphery of a cylindrical sleeve member 3a ′ provided on the inner periphery of the motor rotor 3a.
Therefore, operations such as formation and assembly of the connection portion of the sensor rotor 17a are easier than in the case where the sensor rotor 17a is provided on the motor rotor 3a.

(4) The connecting portion of the flexspline 19c as the flexible external gear of the intermediate shaft 5 as the steering shaft and the annular wave gear reducer 19 as the speed reducer is inside the cylindrical portion 23a of the flexspline 19c. It was made to connect with the bottom part 23b.
Therefore, since the connecting portion is provided in the internal space of the flex spline 19c as a flexible external gear serving as a dead space, the size of the steering device actuator 1 can be suppressed.

(5) The circular spline 19b as a rigid internal gear has a rigid ring shape having internal teeth on the inner periphery, and is fixed to a housing member 20 as a ring-shaped second housing portion as a reduction gear housing portion by a bolt 21. The gap between the outer peripheral surface and the inner peripheral surface of the ring member 8b and the ring-shaped housing member 20 is fitted with a gap.
Accordingly, the positional accuracy of the housing such as the ring member 8b and the housing member 20 and the circular spline 19b can be increased, and the annular member connected to the intermediate shaft 5 that is pivotally supported by the housing such as the ring member 8b and the housing member 20 or the like. The coaxiality of the flex spline 19c as a flexible external gear and the circular spline 19b can be improved, and a smooth wave gear operation can be obtained.

[Example 4]
FIG. 6 is a longitudinal sectional view of the steering device actuator of the fourth embodiment.

The resolver 17 that is a motor rotation angle sensor has the same configuration as that of the third embodiment except that the resolver 17 is provided on the steering wheel side of the electric motor 3. Omitted.
Therefore, the same effects as those of the third embodiment are obtained.

[Example 5]
FIG. 7 is a longitudinal sectional view of the steering device actuator of the fifth embodiment.

Except for the point that the actuator for the steering device is a separate type from the hydraulic power steering device 100, the configuration is the same as that of the fourth embodiment. Description is omitted.
Instead of the sleeve 62, a flex spline 19c is fixed by a bolt 22 to a flange 63 provided integrally with the intermediate shaft 5.
A serration 141 that can be connected to the steering shaft on the hydraulic power steering device side is formed at the end of the intermediate shaft 5 on the negative X-axis direction side.

Next, the function and effect will be described.
The actuator for the steering device according to the fifth embodiment has the following effects in addition to the effects of the fourth embodiment.

(1) The hydraulic power steering device 100 side steering shaft and the steering device actuator side steering shaft are configured as separate members from each other and can be connected.
Accordingly, the degree of freedom in combining the steering device actuator and the hydraulic power steering device is improved.

[Example 6]
FIG. 8 is a longitudinal sectional view of the steering device actuator of the sixth embodiment.

The resolver 17 that is a motor rotation angle sensor has the same configuration as that of the fifth embodiment except that the resolver 17 is provided on the wave gear reducer 19 side of the electric motor 3. The description is omitted.
Therefore, there exists an effect similar to Example 5.

[Example 7]
FIG. 9 is a longitudinal sectional view of the steering device actuator of the seventh embodiment.

Except for the point that the actuator for the steering device is a separate type from the hydraulic power steering device 100, the configuration is the same as that of the second embodiment, and therefore the same components are denoted by the same reference numerals. Description is omitted.
Instead of the sleeve 62, a flex spline 19c is fixed by a bolt 22 to a flange 63 provided integrally with the intermediate shaft 5.
A serration 141 that can be connected to the steering shaft on the hydraulic power steering device side is formed at the end of the intermediate shaft 5 on the negative X-axis direction side.

Next, the function and effect will be described.
The actuator for the steering device according to the seventh embodiment has the following effects in addition to the effects of the second embodiment.

(1) The hydraulic power steering device 100 side steering shaft and the steering device actuator side steering shaft are configured as separate members from each other and can be connected.
Accordingly, the degree of freedom in combining the steering device actuator and the hydraulic power steering device is improved.

[Example 8]
FIG. 10 is a longitudinal sectional view of the steering device actuator of the eighth embodiment.

Except for the point that the actuator for the steering device is a separate type from the hydraulic power steering device 100, the configuration is the same as that of the first embodiment, and therefore the same components are denoted by the same reference numerals. Description is omitted.
Instead of the sleeve 62, a flex spline 19c is fixed by a bolt 22 to a flange 63 provided integrally with the intermediate shaft 5.
A serration 141 that can be connected to the steering shaft on the hydraulic power steering device side is formed at the end of the intermediate shaft 5 on the negative X-axis direction side.

Next, the function and effect will be described.
The actuator for the steering device according to the eighth embodiment has the following effects in addition to the effects of the first embodiment.

(1) The hydraulic power steering device 100 side steering shaft and the steering device actuator side steering shaft are configured as separate members from each other and can be connected.
Accordingly, the degree of freedom in combining the steering device actuator and the hydraulic power steering device is improved.

[Other embodiments]
As mentioned above, although the form for implement | achieving this invention has been demonstrated based on the Example, the concrete structure of this invention is not limited to an Example, The design change of the range which does not deviate from the summary of invention Are included in the present invention.
For example, in the embodiment, the example of the annular wave gear reducer 19 is shown as the reduction mechanism, but a reduction mechanism such as a planetary gear may be used.

The technical idea that can be grasped from the embodiment described above will be described below.
In one aspect of the steering device actuator, the steering shaft that rotates as the steering wheel rotates, a transmission mechanism that transmits the rotation of the steering shaft to the steered wheels, a piston provided in the transmission mechanism, A pair of pressure chambers for generating a force for moving the piston, and a steering device provided between the steering wheel and a hydraulic power steering device that applies a steering force to the steered wheels as the piston moves. An actuator having a motor part accommodating part and a speed reducer accommodating part, a motor rotor provided in the motor part accommodating part and formed in a cylindrical shape so as to surround the steering shaft, and an outer periphery of the motor rotor A motor unit having a stator provided on the motor, and a motor unit provided in the speed reducer housing unit and surrounding the steering shaft It is formed into an annular shape so as have a reduction gear for transmitting the rotational force of the motor unit to the steering shaft.
In a more preferable aspect, in the above aspect, a motor rotation angle sensor that detects a rotation angle of the motor rotor is provided.
According to still another preferred aspect, in the above aspect, the sleeve includes a sleeve member that is formed in a cylindrical shape so as to surround the steering shaft, and is provided on an inner peripheral side of the motor rotor. A sensor rotor provided on the member; and a sensor stator provided on the housing for detecting a rotational position of the sensor rotor.
In still another preferred aspect, in any one of the above aspects, the speed reducer is disposed inside an annular rigid internal gear provided in the housing, and inside the rigid internal gear, and is connected to the steering shaft. An annular flexible external gear and an inner side of the flexible external gear so as to surround the steering shaft, connected to the motor rotor, and flexing the flexible external gear to A wave reducer having a wave generator that partially meshes with a rigid internal gear at two locations and moves a meshing position of the rigid internal gear and the flexible external gear in the circumferential direction. It is.
In still another preferred aspect, in the above aspect, the flexible external gear includes an annular external tooth portion that meshes with the rigid internal gear, and extends from the annular external tooth portion in a rotation axis direction of the steering shaft. A tubular portion, and a bottom portion provided on the opposite side of the annular external tooth portion in the rotational axis direction of the steering shaft of the tubular portion, the steering shaft and the flexible external gear The connection part is provided inside the cylindrical part.
In still another preferred aspect, in the above aspect, the housing includes a first housing part provided on one side in a rotation axis direction of the steering shaft, and a second housing part provided on the other side, The first housing part and the second housing part are connected to each other, and the annular rigid internal gear is fixed to the housing while being sandwiched between the first housing part and the second housing part. The combination of the inner peripheral surface of the housing and the outer peripheral surface of the annular rigid internal gear is a clearance fit.
In still another preferred aspect, in any of the above aspects, the input shaft portion provided on the steering wheel side, the output shaft portion provided on the hydraulic power steering apparatus side, the input shaft portion, and the output An intermediate shaft portion provided between the shaft portions to which the flexible external gear is connected, and the input shaft portion and the intermediate shaft portion are connected to each other via a torsion bar so as to be relatively rotatable, A torque sensor unit that is provided in the housing and detects a relative rotation amount of the input shaft unit and the intermediate shaft unit is further included.
In still another preferred aspect, in the above aspect, the torque sensor unit is provided so as to overlap the motor unit in a direction of a rotation axis of the steering shaft.
In still another preferred aspect, in the above aspect, the torque sensor section is provided closer to the input shaft section than the motor section in the rotation axis direction of the steering shaft.
In still another preferred aspect, in the above aspect, the steering shaft includes an input shaft portion provided on the steering wheel side, an output shaft portion provided on the hydraulic power steering device side, and the input shaft portion. An intermediate shaft portion provided between the output shaft portions to which the flexible external gear is connected, and the input shaft portion and the intermediate shaft portion are connected to each other via a torsion bar so as to be relatively rotatable. And an angle sensor that is provided in the input shaft portion and detects a rotation angle of the input shaft portion, and a detection cycle of the motor rotation angle sensor per one rotation of the motor rotor is the input shaft portion 1 of the angle sensor. It was made equal to the value obtained by multiplying the detection cycle per rotation by the reduction ratio of the wave reducer.
In still another preferred aspect, in any one of the above aspects, the steering shaft is a hydraulic power steering device side steering shaft portion provided in the hydraulic power steering device, and a steering device provided on the housing side. The actuator part side steering shaft part is composed of different members and can be connected.
In still another preferred aspect, in the above aspect, the speed reducer includes an annular rigid internal gear provided in the housing, and an annular rigid gear disposed inside the rigid internal gear and connected to the steering shaft. A flexible external gear and an inner side of the flexible external gear so as to surround the steering shaft, connected to the motor rotor, and flexing the flexible external gear to flex the rigid internal gear A wave reducer having a wave generator that partially meshes with a gear at two locations and moves a meshing position of the rigid internal gear and the flexible external gear in the circumferential direction.
In still another preferred aspect, in the above aspect, the flexible external gear includes an annular external tooth portion that meshes with the rigid internal gear, and extends from the annular external tooth portion in a rotation axis direction of the steering shaft. A tubular portion, and a bottom portion provided on the opposite side of the annular external tooth portion in the rotational axis direction of the steering shaft of the tubular portion, the steering shaft and the flexible external gear The connection part is provided inside the cylindrical part.
In still another preferred aspect, in the above aspect, the housing includes a first housing part provided on one side in a rotation axis direction of the steering shaft, and a second housing part provided on the other side, The first housing part and the second housing part are connected to each other, and the annular rigid internal gear is fixed to the housing while being sandwiched between the first housing part and the second housing part. The combination of the inner peripheral surface of the housing and the outer peripheral surface of the annular rigid internal gear is a clearance fit.

1 Steering device actuator 2 Input shaft (input shaft, steering shaft)
3 Electric motor (motor part)
3a Motor rotor 3a 'Sleeve member 3b Motor stator 4 IC Hall type torque sensor (torque sensor part)
5 Intermediate shaft (intermediate shaft, steering shaft)
6 Torsion bar 8 Motor housing (Motor housing part)
8a Intermediate member 8b Ring member (first housing)
17 Resolver (motor rotation angle sensor)
17a Sensor rotor (sensor rotor part)
17b Sensor stator (sensor stator part)
19 Wave gear reducer (wave reducer)
19a Wave generator
19b Circular Spline (Rigid Internal Gear)
19c flexspline (flexible external gear)
20 Housing member (second housing part, reduction gear housing part)
27 Screw shaft (output shaft, steering shaft)
38 Piston 41 Sector gear (Transmission mechanism)
43 rack (transmission mechanism)
44 rack teeth (transmission mechanism)
46 1st pressure chamber 47 2nd pressure chamber 100 Hydraulic power steering apparatus 110 Resolver (torque sensor part, angle sensor)

Claims (12)

A steering shaft that rotates as the steering wheel rotates,
A transmission mechanism for transmitting the rotation of the steering shaft to the steered wheels;
A piston provided in the transmission mechanism;
A pair of pressure chambers for generating a force to move the piston;
With
An actuator for a steering device provided between the steering wheel and a hydraulic power steering device that applies a steering force to the steered wheels as the piston moves;
A housing having a motor unit housing portion and a reducer housing portion;
A motor rotor provided in the motor part housing part and formed in a cylindrical shape so as to surround the steering shaft;
A motor unit having a stator provided on the outer periphery of the motor rotor;
A speed reducer provided in the speed reducer housing, formed in an annular shape so as to surround the steering shaft, and transmitting a rotational force of the motor portion to the steering shaft;
Having
An actuator for a steering device. The actuator for a steering device according to claim 1,
A motor rotation angle sensor for detecting a rotation angle of the motor rotor;
An actuator for a steering device. The actuator for a steering device according to claim 2,
A sleeve member is formed so as to surround the steering shaft, and is provided on the inner peripheral side of the motor rotor,
The motor rotation angle sensor includes a sensor rotor provided on the sleeve member;
A sensor stator provided in the housing for detecting a rotational position of the sensor rotor;
Having
An actuator for a steering device. The actuator for a steering device according to claim 2,
The speed reducer includes an annular rigid internal gear provided in the housing;
An annular flexible external gear disposed inside the rigid internal gear and connected to the steering shaft;
It is arranged inside the flexible external gear so as to surround the steering shaft, is connected to the motor rotor, and bends the flexible external gear so that it is partially at two positions with respect to the rigid internal gear. And a wave generator that moves the meshing position of the rigid internal gear and the flexible external gear in the circumferential direction,
A wave reducer having
An actuator for a steering device. The actuator for a steering device according to claim 4,
The steering shaft includes an input shaft provided on the steering wheel side,
An output shaft provided on the hydraulic power steering device side;
An intermediate shaft portion provided between the input shaft portion and the output shaft portion to which the flexible external gear is connected;
Have
The input shaft portion and the intermediate shaft portion are connected so as to be relatively rotatable via a torsion bar,
A torque sensor unit provided in the housing for detecting a relative rotation amount of the input shaft unit and the intermediate shaft unit;
An actuator for a steering device. The actuator for a steering device according to claim 5,
The torque sensor unit is provided so as to overlap the motor unit in the direction of the rotation axis of the steering shaft.
An actuator for a steering device. The actuator for a steering device according to claim 5,
The torque sensor unit is provided closer to the input shaft unit than the motor unit in the rotation axis direction of the steering shaft.
An actuator for a steering device. The actuator for a steering device according to claim 4,
The steering shaft includes an input shaft provided on the steering wheel side,
An output shaft provided on the hydraulic power steering device side;
An intermediate shaft portion provided between the input shaft portion and the output shaft portion to which the flexible external gear is connected;
Have
The input shaft portion and the intermediate shaft portion are connected so as to be relatively rotatable via a torsion bar,
An angle sensor provided on the input shaft portion for detecting a rotation angle of the input shaft portion;
The detection cycle per rotation of the motor rotor of the motor rotation angle sensor is equal to a value obtained by multiplying the detection cycle per rotation of the input shaft portion of the angle sensor by the reduction ratio of the wave reducer.
An actuator for a steering device. The actuator for a steering apparatus according to claim 1,
In the steering shaft, the hydraulic power steering device side steering shaft portion provided in the hydraulic power steering device and the steering device actuator side steering shaft portion provided in the housing are configured as separate members. And are connectable,
An actuator for a steering device. The actuator for a steering apparatus according to claim 1,
The speed reducer includes an annular rigid internal gear provided in the housing;
An annular flexible external gear disposed inside the rigid internal gear and connected to the steering shaft;
It is arranged inside the flexible external gear so as to surround the steering shaft, is connected to the motor rotor, and bends the flexible external gear so that it is partially at two positions with respect to the rigid internal gear. And a wave generator that moves the meshing position of the rigid internal gear and the flexible external gear in the circumferential direction,
A wave reducer having
An actuator for a steering device. The actuator for a steering device according to claim 10,
The flexible external gear includes an annular external tooth portion meshing with the rigid internal gear,
A cylindrical portion extending in the direction of the rotation axis of the steering shaft from the annular outer tooth portion;
A bottom portion provided on the opposite side of the annular external tooth portion in the rotation axis direction of the steering shaft among the cylindrical portions;
Have
A connection portion between the steering shaft and the flexible external gear is provided inside the cylindrical portion.
An actuator for a steering device. The actuator for a steering device according to claim 10,
The housing includes a first housing part provided on one side in the rotational axis direction of the steering shaft and a second housing part provided on the other side,
Have
The first housing part and the second housing part are connected to each other;
The annular rigid internal gear is fixed to the housing in a state of being sandwiched between the first housing part and the second housing part,
The combination of the inner peripheral surface of the housing and the outer peripheral surface of the annular rigid internal gear is a clearance fit.
A steering actuator device characterized by that.

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