JP3109920B2 - Steering gear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering apparatus for steering wheels of an automobile or the like, and more particularly to a steering apparatus capable of automatically adjusting a small steering angle based on a cross wind detected by a sensor.

[0002]

2. Description of the Related Art In Japanese Patent Application No. 3-53374, which is a steering apparatus of this kind, proposed by the applicant, an output shaft connected to a power steering shaft 1 of a power steering apparatus as shown in FIG. 2
The first gear 3 fixed to the output shaft 2 and the second and third gears 4 supported by the carrier 6
The wheel is decelerated and rotated via the shafts a and 4b, and the rack bar 7 meshing with the pinion 5 is axially moved to steer the wheels via a steering link (not shown). A servo motor (not shown) which is operated based on a detection result of a cross wind sensor or the like rotates the carrier 6 around the output shaft 2 via a worm 8 connected to an output shaft of the servo motor and a sector gear 6a provided on the carrier 6. Let it. Accordingly, the rotation due to the rotation of the carrier 6 (the rotation of the pinion 5 due to the revolution and rotation of the second gear 4a around the first gear 3) is added to the deceleration rotation of the pinion 5 due to the rotation of the output shaft 2 to the pinion 5 (the rotation of the pinion 5). Or subtraction), and the fine steering angle adjustment based on the cross wind or the like is automatically performed.

[0003]

The above prior art is satisfactory as a function of fine steering angle adjustment itself, but increases the number of gears and bearings, so that the cost increases.
Since the third gears 4a, 4b and the carrier 6 are largely protruded to the side and rotate, the steering device becomes large as a whole, and there is a problem that the mountability to the vehicle is poor.

An object of the present invention is to solve the above-mentioned problems by simplifying the structure of a steering device capable of automatically performing such fine steering angle adjustment and reducing the size of the entire steering device.

[0005]

For this purpose, as shown in FIGS. 1 to 6, a steering apparatus according to the present invention has one end connected to a steering wheel, is rotated together, and the other is a power steering. An input shaft 11 in which a shaft 12 is coaxially and elastically connected so as to be relatively rotatable, an output operating member 14 for steering wheels via a steering link, and a booster for applying an assist force to the output operating member 14 A device 30 includes a first element 21 connected to the input shaft 11 and a second element 22 connected to the power steering shaft 12, and operates according to a relative rotation between the two elements to increase the force. The device 30 is the output actuating member 1
A control device for changing the assist force applied to the power steering shaft; and a shaft including at least an output shaft connected to the output operation member and arranged coaxially with the power steering shaft. In a steering system including an interlocking device 44 for connecting the 12 and the second element 22 to the output operation member 14 and the housing 10 supporting these members, at least a part of the shafts of the interlocking device 44 is supported. The power steering shaft 12 with respect to the housing 10
A carrier 40 supported coaxially and movably in the axial direction thereof, and displacing the positional relationship of the second element 22 with respect to the position of the output operation member 14 by the axial movement thereof;
A control unit 45 for operating a servo motor 43 for axially moving the carrier 40 in accordance with the detection states of the sensors 46, 47 and 48 is provided.

The interlocking device 44 of the invention is supported by the housing 10 so as to be rotatable coaxially with the power steering shaft 12 as shown in FIGS.
4 and an intermediate shaft 12B whose both ends are connected to the power steering shaft 12 and the output shaft 13 so as to be relatively movable in the axial direction, and transmits rotation between the two shafts.
And engagement means 22b and 23 provided between the intermediate shaft 12B and the second element 22 to rotate the second element 22 with respect to the intermediate shaft 12B in accordance with the axial movement of the intermediate shaft 12B. The carrier 40 may be configured to support the intermediate shaft 12B to be axially moved.

[0007] Alternatively, the interlocking device 44 of the first invention.
As shown in FIG. 4, an output shaft 13 is disposed coaxially with the power steering shaft 12 and has one end connected to the power steering shaft 12 so as to be relatively movable in the axial direction and capable of transmitting rotation. A helical pinion 15a formed on the output shaft 13 and a rack and pinion mechanism 15 including a rack 15b formed on a rack bar 14 constituting the output operating member and meshing with the pinion 15a are provided. The shaft 13 may be supported and axially moved.

In each of the above inventions, the input shaft 11 may be connected to a steering wheel via a front wheel steering device 50, and the output operating member 14 may steer rear wheels via a steering link.

[0009]

The rotation of the input shaft 11 that rotates together with the steering wheel is transmitted to the output operating member 14 via the interlocking device 44.
Steer the wheels via the steering link. At this time, the control device 2 is controlled according to the relative movement between the first element 21 and the second element 22.
0 operates to apply an assist force to the output operation member 14.

The control unit 45 includes sensors 46, 47, 4
By operating the servo motor 43 according to the detection state of 8,
The carrier 40 is moved in the axial direction. This axial movement causes the second element 22 to move relative to the position of the output actuating member 14.
Is displaced, whereby the control device 20 is actuated to apply an assist force to the intensifier 30. Therefore, the output operating member 14 moves, and the steering angle of the wheel is adjusted by a predetermined amount according to the displacement. Stop. The fine steering angle adjustment by the servo motor 43 is automatically performed in this manner.

[0011]

As described above, according to the present invention, not only can the fine steering angle adjustment be performed automatically, but also the interlocking device for connecting the second element of the control device and the power steering shaft to the output operating member. Does not require a large number of gears and bearings as in the prior art because it is composed of shafts arranged coaxially with the power steering shaft, and is displaced by the servomotor to displace the positional relationship of the second element with the output operation member. Since the carrier for performing the fine steering angle adjustment is arranged coaxially with the power steering shaft and moves in the axial direction, the carrier does not protrude to the side unlike the conventional carrier. Therefore, the structure is simplified, so that the cost is reduced. Further, since the steering device is downsized as a whole, the mountability on a vehicle is improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a first embodiment shown in FIGS. In the first embodiment, the present invention is applied to a front wheel steering device.

As shown in FIG. 1, a housing 10 of the front wheel steering system according to the present embodiment comprises a valve housing 10a and a gear housing 10b fixed to each other by screws. The input shaft 11 and the power steering shaft 12 arranged coaxially with each other are supported in the valve housing 10a via bearings 17a and 17c, and are elastically connected by a torsion bar 16 so as to be relatively rotatable.

An output shaft 13 is supported on the gear housing 10b coaxially with the power steering shaft 12 by bearings 18a and 18b so as to be rotatable only. Further, a rack bar 14 is supported so as to be axially movable crossing the output shaft 13 three-dimensionally, and these two 13 and 14 are formed on a helical pinion 15 a formed on the output shaft 13 and a part of the rack bar 14. The rack and pinion mechanism 15 includes a rack and pinion 15a meshed with the pinion 15a. These 13, 14
Is not limited to the illustrated rack and pinion mechanism, but may be other types such as a ball screw type and a worm pin type.

An intermediate shaft 12B coaxially arranged with the power steering shaft 12 and the output shaft 13 has a front end connected to the power steering shaft 12 by a slide key 12a and a key groove 12b, and a rear end formed by a slide key 12c and a slide key 12c. Output shaft 13 by keyway 13a
To transmit rotation between the two shafts 12, 13, but can move in the axial direction. This intermediate shaft 12
B is connected via two bearings 19 so as to move in the axial direction together with a carrier 40 described below. These intermediate shaft 12B, output shaft 13, interlocking mechanism 15, and keyway 1
2b, 13a and the like constitute an interlocking device 44 for connecting the power steering shaft 12 and the sleeve valve member 22 to the rack bar 14.

A cylindrical carrier 40 is threadedly engaged with an inner peripheral surface of a cylindrical worm gear 41 supported by the valve housing 10a coaxially with the power steering shaft 12 by two bearings 17c. The worm gear 41 is connected to the valve housing 10.
a and is rotated by meshing with a worm 42 connected to an output shaft of a servo motor 43 described later. Carrier 4
Reference numeral 0 denotes a power steering shaft when the engagement groove 40a formed in a part of the inner peripheral surface in the axial direction is engaged with the rotation preventing pin 28 fixed to the valve housing 10a to prevent rotation, and the worm gear 41 rotates. 12, the intermediate shaft 12B is moved in the axial direction via a bearing 19.

As shown in FIG. 1, the front wheel steering device of the present embodiment is provided with a hydraulic power steering device including a servo valve 20 and a power cylinder 30. The rotor valve member 21 of the servo valve 20 is formed integrally with the input shaft 11, and the sleeve valve member 22 has inner and outer peripheral surfaces rotatably fitted to the outer peripheral surface of the rotor valve member 21 and the inner peripheral surface of the valve housing 10a, respectively. The axial movement of the sleeve valve member 22 with respect to the rotor valve member 21 is restricted by snap rings 80 and 81 provided at both ends of the sleeve valve member 22. Further, the sleeve valve member 22 is connected to the intermediate shaft 12B by an engagement means including an engagement pin 23 and a slit 22b. Engagement pin 2 implanted and fixed to intermediate shaft 12B
2, the slit 22b, which is engaged with substantially no gap, is formed in the extension cylindrical portion 22a of the sleeve valve member 22 so as to be inclined with respect to the axial direction, as shown in FIG. Move to the power steering shaft 12,
Sleeve valve member 2 for intermediate shaft 12B and output shaft 13
The relative angle of 2 changes. The valve housing 10a has four ports of the servo valve 20, that is, an input port 25,
A discharge port 26 and a pair of distribution ports 27a, 27b are formed.

The power cylinder 30 is provided in the middle of the rack bar 14 and is formed integrally with the gear housing 10b to penetrate the rack bar 14 coaxially and liquid-tightly. 3
1 is constituted by a piston 32 which is fitted in a liquid-tight manner on the inner circumference and separates the inside into left and right working chambers. The left and right working chambers are respectively connected to the distribution ports 27a and 27b of the servo valve 20 by communication paths, and the input port 25 and the discharge port 26 are respectively connected to the supply pump 3 by the communication paths.
5 and the reservoir 36.

The servo valve 20 is provided with a torsion bar 16 by a torque acting between the input shaft 11 and its power steering shaft 12.
Of the working fluid of the power cylinder 30 from the supply pump 35 to each working chamber of the power cylinder 30 according to the relative rotation of the rotor valve member 21 and the sleeve valve member 22 due to the slight torsion and the axial movement of the intermediate shaft 12B. The discharge of the working fluid from the working chamber to the reservoir 36 is controlled by each of the distribution ports 25, 26, 27a,
27b. As a result, a steering assist force corresponding to the relative rotation of the two members 21 and 22 is applied to the front wheels via the rack bar 14.

The worm 4 meshed with the worm gear 41
As shown in FIG.
Lateral wind sensor 46 composed of a lateral accelerometer and the like, vehicle speed sensor 47
And is controlled by the control unit 45 based on the input from the steering angle sensor 48.

Next, the operation of the first embodiment will be described.
When the input shaft 11 rotates together with the steering wheel (both not shown) via the handle shaft, the power steering shaft 12 rotates together via the torsion bar 16. This rotation is transmitted to the output shaft 13 via the intermediate shaft 12B, is converted to axial movement of the rack bar 14 via the rack and pinion mechanism 15, and steers the front wheels via links (not shown). At the time of this steering, the torsion bar 16 is twisted by the steering torque applied to the input shaft 11 so that the rotor valve member 21 and the sleeve valve member 22 rotate relatively, and the working fluid from the supply pump 35 is supplied to and discharged from the power cylinder 30. As a result, an assist force is applied to the rack bar 14 to perform power steering.

When the crosswind sensor 46 does not detect crosswind, the intermediate shaft 12B is at the neutral position in the axial movement, and when the input shaft 11 is at a certain steering angle (including the steering neutral position), the output shaft 13 and The meshing rack bar 14 is at a predetermined position corresponding to the steering angle. The sleeve valve member 22 has a predetermined positional relationship corresponding to the positions of the output shaft 13 and the rack bar 14, and the phase difference with the rotor valve member 21 is almost zero. In this state,
If the crosswind sensor 46 detects a crosswind, the control unit 45
Rotates the servo motor 43 by a predetermined amount in accordance with the detected strength of the cross wind and the vehicle speed and the steering angle detected by the vehicle speed sensor 47 and the steering angle sensor 48 at that time, and rotates the worm gear 41 through the worm 42. The carrier 40 and the intermediate shaft 12B are moved by a predetermined amount in the axial direction.

By this movement, the sleeve valve member 22 connected to the intermediate shaft 12B via the engaging pin 23 and the inclined slit 22b is rotated by a predetermined angle with respect to the intermediate shaft 12B. That is, the sleeve valve member 22 is displaced by the same angle from the original predetermined positional relationship with respect to the rack bar 14, and is also displaced by the same angle with respect to the rotor valve member 21, so that the position between the sleeve valve member 21 and the rotor valve member 21 is changed. The phase difference increases.
Since the servo valve 20 is actuated by the increase in the phase difference, the power cylinder 30 applies an assisting force to the rack bar 14 to move the same, and the movement of the rack bar 14
The rack bar 14 stops when the phase difference with the rotor valve member 21 returns to almost 0 by being fed back to the sleeve valve member 22 through. That is, if the crosswind sensor 46 detects a crosswind at a certain steering wheel angle, the position of the rack bar 14 is automatically adjusted by an amount corresponding to the strength of the crosswind, the vehicle speed and the steering angle as compared with the case where there is no crosswind. As a result, the steering angle of the front wheels is also adjusted. This modification amount by the servo motor 43 is an amount necessary for modifying the change in the traveling direction of the vehicle due to the crosswind, and is determined according to the characteristics of the vehicle.

According to the first embodiment, the sleeve valve member 22 of the servo valve 20 and the power steering shaft 12 are connected to the rack bar 14.
The main members of the interlocking device 44 connected to the power steering shaft 12 are the intermediate shaft 12B and the output shaft 13 arranged coaxially with the power steering shaft 12, and are moved by the servomotor 43 via the worm gear 41 and the worm 42 and the output shaft 13 and The carrier 40 that performs a fine adjustment of the steering angle by displacing the positional relationship of the sleeve valve member 22 with respect to the rack bar 14 is a power steering shaft 1.
Since it is arranged coaxially with 2 and moves in its axial direction,
The number of parts is small, the structure is simplified, and these members do not protrude to the side. Therefore, the structure is simplified, so that the cost is reduced. Further, since the steering device is downsized as a whole, the mountability on a vehicle is improved.

Next, a second embodiment shown in FIG. 4 will be described.
This second embodiment is also applied to the front wheel steering device as in the first embodiment. The power steering device including the servo valve 20 and the power cylinder 30 is provided between the input shaft 11 and the power steering shaft 12. A point where a reaction force mechanism 29 for changing the power steering characteristic by changing the torsion spring characteristic is provided, and a point that the sleeve valve member 22 is fixedly connected to the power steering shaft 12 via the engaging pin 23. Except for the above, it is substantially the same as the first embodiment.

In the second embodiment, a front end of an output shaft 13 arranged coaxially with a power steering shaft 12 is provided with a sliding key 12.
a and the rear end of the power steering shaft 12 via the keyway 13a so as to be slidable only in the axial direction. A carrier 40 is screwed into a screw hole 10c formed coaxially with the power steering shaft 12 at the rear end of the gear housing 10b so as to be able to advance and retreat.
The rear end of the output shaft 13 is fitted to the inner ring of the bearing 18b in which the outer ring is fixed to the inner periphery of the carrier 40 by a holding screw 40b, and is fixed by a nut 13b. Fan-shaped worm gear 4 integrally formed at the front of carrier 40
Reference numeral 1 denotes a servo motor 4 supported by a gear housing 10b and controlled by a control unit 45 similar to that of the first embodiment.
3 is in mesh with the worm 42 connected to the output shaft. If the carrier 40 is rotated by the servomotor 43 via the worm 42 and the worm gear 41, the screw hole 10c
The shaft 18 moves in the axial direction of the power steering shaft 12 by screw engagement with the power steering shaft 12, and moves the output shaft 13 in the axial direction via the bearing 18b.

As in the first embodiment, the gear housing 10b
A rack bar 14 is supported so as to be axially movable crossing the output shaft 13 three-dimensionally.
Helical pinion 15a formed on the rack bar 14
Rack 1 formed on a portion of the rack and meshing with the pinion 15a
5b are interlocked with each other by a rack and pinion mechanism 15 composed of 5b.

In the second embodiment, when the cross wind sensor 46 detects a cross wind, the control unit 45 determines the strength of the detected cross wind, the vehicle speed and the steering angle detected by the vehicle speed sensor 47 and the steering angle sensor 48 at that time. According to the servo motor 43
Is rotated by a predetermined amount, and the worm gear 41 is rotated via the worm 42 to move the carrier 40 and the output shaft 13 in the axial direction by a predetermined amount.

By this movement, the output shaft 13 engaged with the rack 15b of the rack bar 14 via the helical pinion 15a and the sleeve valve member 2 fixedly connected thereto are provided.
2 is rotated by a predetermined angle. That is, the sleeve valve member 22
Is rotated by the same angle from the original predetermined positional relationship with respect to the rack bar 14, and is also rotated by the same angle with respect to the rotor valve member 21, so that the phase difference with the rotor valve member 21 increases. As a result, the power steering device operates as in the first embodiment, and the steering angle of the front wheels is automatically adjusted by a predetermined amount according to the strength of the cross wind, the vehicle speed, and the steering angle. This modification amount is the first
Determined in the same manner as in the embodiment.

According to the second embodiment, the sleeve valve member 22 of the servo valve 20 and the power steering shaft 12 are connected to the rack bar 14.
The main member of the interlocking device 44 connected to the power steering shaft 12 is the output shaft 13 arranged coaxially with the power steering shaft 12, and is moved by the servomotor 43 via the worm gear 41 and the worm 42 to move the sleeve valve member 22 to the rack bar 14.
Since the carrier 40 for finely adjusting the steering angle by displacing the positional relationship is arranged coaxially with the power steering shaft 12 and moves in the axial direction thereof, the structure is simplified and the cost is reduced as in the first embodiment. And the mountability on vehicles improves. Further, in the second embodiment, the sleeve valve member 22 is rotated and displaced from the original predetermined positional relationship with respect to the rack bar 14 by using the helical pinion 15a originally provided in the rack and pinion type steering device. Therefore, the structure is further simplified as compared with the first embodiment.

Next, a third embodiment shown in FIGS. 5 and 6 will be described. In the third embodiment, the present invention is applied to a rear wheel steering device of a four-wheel steering device.

First, the overall structure of the four-wheel steering system will be described with reference to FIG. A predetermined amount of working fluid sucked and delivered from the reservoir 36 by the supply pump 35 driven by the engine E of the automobile is divided at a predetermined ratio by the flow dividing valve 37, and one of them is supplied to the front wheel steering device 50. The other is supplied to the rear wheel steering device, and the used working fluid is returned to the reservoir 36.

A front wheel servo valve 51 is provided in the middle of a handle shaft 56 of the front wheel steering device 50, and a front wheel power cylinder 54 is provided on the front wheel rack bar 53. The front wheel servo valve 51 is inputted from a steering wheel 55. It operates in accordance with the steering wheel torque and controls the supply and discharge of the working fluid supplied via the flow dividing valve 37 to the left and right working chambers of the front wheel power cylinder 54. The amplified steering force is output to the front wheel rack bar 53, and the left and right front wheels 59 are steered via tie rods 57 and knuckle arms 58 provided at both ends thereof.

Next, the rear wheel steering apparatus according to the third embodiment will be described mainly with reference to FIG. This rear wheel steering device has an input shaft 11
Is substantially the same as the steering device of the second embodiment except that a steering characteristic imparting mechanism 60 and an assist delay avoidance mechanism 70 are provided at a portion where the steering wheel is connected to the front wheel steering device 50. The steering characteristic imparting mechanism 60 and the assist delay avoiding mechanism 70 are provided in a front housing 10d and a cap portion 10e which are fixed to the tip of the valve housing 10a by screws.

A driven rotary member 63 supported in the front housing 10d so as to be rotatable coaxially with the input shaft 11 is connected to the tip of the input shaft 11 via an assist delay avoiding mechanism 70. The assist delay avoiding mechanism 70 includes an intermediate rotating member 72 and an output rotating member 74 supported by the front housing 10d via bearings.
The rotating members 72 and 74 are connected by spiral springs 71 and 73 that transmit torque up to a predetermined value, respectively. If the transmission torque between the driven rotary member 63 and the input shaft 11 is equal to or less than a predetermined value, the rotation is transmitted as it is, and if it exceeds the predetermined value, the spiral springs 71 and 73 are bent and the rotation is not transmitted.

An input rotary member 61 is supported in the cap portion 10e so as to be rotatable around a rotation axis parallel to the input shaft 11, and a steering characteristic imparting mechanism 60 is provided between the input rotary member 61 and the driven rotary member 63. ing. As shown in FIG.
The steering characteristic imparting mechanism 60 includes a cam groove 60a and a projection 60b. The cam groove 60a provided in the input rotary member 61 has a symmetrical figure-eight shape. The protrusion 60b is composed of a support pin fixed to the driven rotary member 63 and a roller rotatably supported by the support pin. When the steering is in the neutral position, the protrusion 60b is located on a line of symmetry of the cam groove 60a. The steering characteristic imparting mechanism 60 transmits the rotation of the input rotary member 61 to the driven rotary member 63 while gradually increasing the speed increase ratio as the steering handle 55 rotates from the neutral steering position. The neutral lock pin 64 eccentrically screwed into the cap portion 10e is normally in the retracted position as shown in the figure, but engages with the concave portion 61a formed in the input rotary member 61 in the forward state to steer the input rotary member 61 to the neutral position. Position in position.

As shown in FIGS. 5 and 6, a pair of rear operation cables 68a and 68b have pulley portions 62 each having a rear end entering the cap portion 21a from the radial direction and integrally formed with the input rotary member 61. , And each front end is wound around an idle pulley 67 provided in a cable adjusting device 66. The front operation cable 65 has a front end attached to a bracket 53a fixed to the front wheel rack bar 53, and a rear end connected to a part of the rear operation cables 68a, 68b. As a result, the input rotary member 61 is rotated in proportion to the axial movement of the front wheel rack bar 53, and this rotation is performed via the rack and pinion mechanism 15.
The left and right rear wheels 79 are steered via the tie rod 77 and the knuckle arm 78. Each of the operation cables 65, 68a, and 68b includes an outer tube having both ends fixed to each housing such as the cap portion 21a.

The servo motor 43 of the third embodiment is controlled by a control unit 45 based on inputs from a vehicle speed sensor 47 and a steering angle sensor 48, as shown in FIG. The control unit 45 does not operate the servomotor 43 when the vehicle speed detected by the vehicle speed sensor 47 is low.

When the steering wheel 55 is turned from the neutral position, the front wheel steering device 50 operates as described above to steer the left and right front wheels 59. At the same time, the front operation cable 6
5. Cable adjusting device 66 and rear operation cable 68
The input rotary member 61 is rotated via the a and 68b, and the steering characteristic imparting mechanism 60, the assist delay avoiding mechanism 70, the input shaft 11, the power steering shaft 12, the output shaft 13, the rack and pinion mechanism 15, and the rack bar 14 are moved. Through this, the rear wheel 79 is steered. When the servomotor 43 is not operated during low-speed running, the steering direction of the rear wheel 79 is in the opposite phase to that of the front wheel 59.

In middle / high speed running, the control unit 45 rotates the servo motor 43 by a predetermined amount according to the vehicle speed and the steering angle detected by the vehicle speed sensor 47 and the steering angle sensor 48,
As in the second embodiment, the output shaft 13 and the sleeve valve member 22 fixedly connected thereto are rotated by a predetermined angle. That is, the sleeve valve member 22 is displaced by the same angle from the original predetermined positional relationship with respect to the rack bar 14, and is displaced by the same angle with respect to the rotor valve member 21 so that the phase difference between the sleeve valve member 22 and the rotor valve member 21 is reduced. Increase. As a result, the power steering device operates, and the steering angle of the rear wheel is automatically adjusted by a predetermined amount according to the vehicle speed and the steering angle. The direction of this modification is rear wheel 79
In the same phase as the front wheels 59, and the amount of modification is determined so as to increase as the vehicle speed increases. As a result, the steering of the rear wheel 79 is stopped near the middle speed, and the steering of the rear wheel 79 is performed in the same phase as the front wheel 59 at a high speed.

In a normal state, since the rear wheel steering torque applied to the input shaft 11 is small, the assist delay avoiding mechanism 7
0 does not operate, and the rotation of the driven rotary member 63 is transmitted to the operating shaft 11 as it is to operate the rear wheel servo valve 20. When the rear wheel 79 falls into the groove and the rear wheel steering torque increases, the spiral springs 71 and 73 of the assist delay avoidance mechanism 70 bend, and an excessive force is applied to the operation cables 65, 68a and 68b to apply these forces. No damage. In the third embodiment, substantially the same effects as in the above-described second embodiment can be obtained.

In each of the above embodiments, an example using a hydraulic power steering device is shown. However, the present invention uses another type of power steering device, for example, an electric power steering device. Can also be implemented.

[Brief description of the drawings]

FIG. 1 is an overall longitudinal sectional view of a first embodiment of a steering device according to the present invention.

FIG. 2 is a partial side view of a coupling portion between an intermediate shaft and a sleeve valve member according to the first embodiment.

FIG. 3 is a block diagram showing a control relationship of the first embodiment.

FIG. 4 is an overall vertical sectional view of a second embodiment.

FIG. 5 is an overall vertical sectional view of a third embodiment.

FIG. 6 is a schematic diagram showing the entirety of a four-wheel steering device employing a third embodiment.

FIG. 7 is an overall vertical sectional view of an example of a conventional steering device.

[Explanation of symbols]

10 housing, 11 input shaft, 12 power steering shaft
12B: intermediate shaft, 13: output shaft, 14: output operating member (rack bar), 15: interlocking mechanism (rack and pinion mechanism), 15a: pinion, 15b: rack, 20: control device, 21: first element ( Rotor valve member), 22... Second element (sleeve valve member), 22 b, 23.
... Intensifier, 40 ... Carrier, 44 ... Interlocking device, 45 ...
Control unit, 46, 47, 48 ... sensor, 50 ... front wheel steering device.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiji Kawakami 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Ikuo Kushiro 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation ( 72) Inventor Satoru Niwa 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (56) References JP-A-3-53374 (JP, U) JP-A 4-71377 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B62D 5/083 B62D 5/22 B62D 6/00

Claims (4)

(57) [Claims] An input shaft having one end connected to a steering wheel and rotated together, and a power steering shaft coaxially and resiliently connected to the other end so as to be relatively rotatable to a certain extent, via a steering link. An output actuating member for steering the wheels by means of a steering wheel, an intensifier for applying an assist force to the output actuating member, a first element connected to the input shaft, and a second element connected to the power steering shaft. A control device that operates in response to relative rotation between elements to change an assist force applied to the output operation member by the booster; and a power steering shaft including at least an output shaft connected to the output operation member. An interlocking device for connecting the power steering shaft and the second element to the output operating member, and a housing that supports these members. And at least part of the shafts are supported by the housing so as to be coaxial with the power steering shaft and movably in the axial direction thereof, and the axial movement of the second element position with respect to the position of the output operation member. A steering device comprising: a carrier for displacing the relationship; and a control unit for operating a servomotor for axially moving the carrier in accordance with a detection state of a sensor. 2. An interlocking device comprising: an output shaft supported by the housing so as to be rotatable coaxially with the power steering shaft and interlocked with the output operating member; and both ends of the output shaft are connected to the power steering shaft and the output shaft, respectively. An intermediate shaft that is connected so as to be relatively movable in the axial direction and transmits rotation between the two shafts; and an intermediate shaft that is provided between the intermediate shaft and the second element in accordance with axial movement of the intermediate shaft. 2. The steering apparatus according to claim 1, further comprising an engagement means for rotating the carrier, wherein the carrier supports the intermediate shaft to be axially moved. 3. An output shaft disposed coaxially with the power steering shaft, one end of which is connected to the power steering shaft so as to be relatively movable in the axial direction and capable of transmitting rotation, and an output shaft connected to the output shaft. A rack and pinion mechanism comprising a formed helical pinion and a rack formed on a rack bar constituting the output operation member, the rack and pinion mechanism comprising a rack meshing with the pinion, wherein the carrier supports the output shaft and axially moves. The steering device according to claim 1. 4. The steering according to claim 1, wherein the input shaft is connected to a steering wheel via a front wheel steering device, and the output operating member steers rear wheels via a steering link. apparatus.