JP3299588B2 - Power steering reaction force device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power steering reaction device for operating a power assist actuator while relatively rotating an input shaft and an output shaft.

[0002]

2. Description of the Related Art In a conventional apparatus, an input shaft and an output shaft are connected via a torsion bar, and a torsional force of the torsion bar when the two shafts are relatively rotated is a pseudo reaction force. .

In the conventional reaction device as described above, the reaction force is uniquely determined by the rigidity of the torsion bar. When running, the steering wheel is too light, and the running stability is impaired. Conversely,
In order to maintain running stability at high speeds, there was a conflicting problem that the reaction force during stationary operation became too large. SUMMARY OF THE INVENTION It is an object of the present invention to provide a device in which a steering reaction force can be freely adjusted to improve the steering characteristics of a vehicle.

[0003]

According to the present invention, an input shaft and an output shaft are provided in a casing, and a power steering device for operating a power assist actuator by relatively rotating the input shaft and the output shaft. Force device is assumed. Based on the above equipment, the first
The invention is arranged in parallel with the leaf springs fixed to said input shaft, fixed to the plate spring with respect to the axial direction of the input shaft
A yoke that is, fixed to the output shaft and a side bushing which is provided opposite to the yoke, the plate spring is a disc-shaped, with its inner side is fixed to the input shaft, its periphery is fixed to the yoke, when providing holes for adjusting the elastic force between these within the outer Tomo
In the same place on the circumference of the opposing surface of the yoke and the side bush, inclined grooves that gradually become shallower in the circumferential direction are formed, and a ball is interposed between these inclined grooves.
Further an electromagnet fixed to the casing, together with the above yoke secures the permanent magnet, these two magnets are opposed, moreover, the permanent magnet has one polarity to the opposite side of the electromagnet, its On the opposite side to the opposite surface, the other polarity is provided, and further, a controller for controlling the exciting current of the electromagnet is provided, and the permanent magnet fixed to the yoke moves by exciting or not exciting the electromagnet.
The present invention is characterized in that the yoke is moved only in the axial direction of the input shaft. The second invention relates to an electromagnet,
When applying no excitation current, the pressing force to the side bush side of the yoke is reduced by not generate an elastic force of the leaf spring itself to the yoke by applying a magnetizing current
In this case , the pressing force on the side bush of the yoke is increased by the elastic force of the leaf spring .

[0004]

Since the present invention is configured as described above,
If the exciting current to the electromagnet is controlled, the yoke can be moved toward the side bush. When the yoke moves toward the side bush in this manner, the pressing force against the ball interposed between the side bush and the yoke increases, so that when the input shaft and the output shaft are relatively rotated, the pressing force is large. Power is required, and eventually the steering reaction force can be increased.

According to the reaction force device of the present invention, the steering reaction force can be freely adjusted according to the traveling conditions, so that stable traveling can always be realized, and the steerability can be improved. Further, in the present invention, the relative rotation regulation is performed only by the leaf spring.
It can reduce hysteresis of moving parts and reduce the number of parts.
It can be significantly reduced. Further, the present invention provides a yoke
Is placed parallel to the axis of the input shaft to excite the electromagnet.
By magnetizing or de-energizing, move the yoke
The device is compact because
And a single yoke suffices for easy control
You. In addition, by using a leaf spring,
Since there are no moving parts, frictional resistance is low
There are effects such as improvement in response.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment shown in FIGS. 1 to 4 rotatably supports an output shaft 2 having a pinion 1 and an input shaft 3 linked to a steering wheel (not shown) in a casing C. are doing. The two shafts 2 and 3 are connected via a torsion bar 4. A rotary sleeve 5 is fixed to the output shaft 2 with pins 6 and a rotary pool 7 is integrally formed with the input shaft 3. The rotary sleeve 5 and the rotary pool 7 form a rotary valve V. Constitute. The output shaft 2 is formed integrally with the pinion 1, and the pinion 1 is engaged with a rack formed on the rack shaft 8. This rack shaft 8
The thrust is exerted by a power cylinder (not shown), and wheels are linked to both ends thereof.

Now, when the input shaft 3 is rotated by turning the steering wheel, the rotational force is transmitted to the output shaft 2 via the torsion bar 4. However, since the ground contact resistance of the wheels acts on the output shaft 2 via the rack shaft 8, the output shaft 2 does not rotate at this time, and the two shafts 2 and 3 are relatively rotated while twisting the torsion bar 4. Rotate. Thus, output shaft 2
When the input shaft 3 and the input shaft 3 rotate relative to each other, the rotary sleeve 5 of the rotary valve V and the rotary spool 7 are switched to supply pressure oil to one of the power cylinders and communicate the other to the tank. As a result, the power cylinder operates and supplies pressure oil to the rack shaft.

When the power cylinder operates, the rack shaft 8 moves accordingly, so that the wheels linked to the rack shaft 8 are steered. When the handle is stopped at a certain operation position, the input shaft 3 also stops, but the output shaft 2 is
Stop when you catch up with. That is, when the output shaft 2 catches up with the input shaft 3, the relative position between the rotary sleeve 5 of the rotary valve V and the rotary pool 7 becomes the same as in the neutral state, so that the operation of the power cylinder stops, and the rack The shaft 8 and the output shaft 2 will also stop. A side bush 9 shown in FIG. 2 is fixed to one end of the rotary sleeve 5 as described above. A yoke 10 is slidably fitted to the input shaft 3, and one side of the yoke 10 faces the side bush 9.

As shown in FIGS. 2 and 3, three inclined grooves 11 and 12 are formed on the opposing surfaces of the side bush 9 and the yoke 10 at predetermined intervals in the circumferential direction. The inclined grooves 11 and 12 have wall surfaces 11 on both sides thereof.
a and 12a are formed, and the depth of the groove at the center thereof is made the deepest, and the depth is gradually reduced toward the circumferential direction. The inclined grooves 11 and 12 of the side bush 9 and the yoke 10 are opposed to each other, and the ball 13 is interposed between the opposed inclined grooves. The yoke 10 as described above is slidable between the input shaft 3 and the input shaft 3 via a bearing 14, and an elastic body is provided on the side opposite to the side where the inclined groove 12 is formed .
As an example, one end of a metallic bellows 15 is fixed.
The other end of the bellows 15 is fixed to the ring 16,
The ring 16 is fixed to the input shaft 3 with a set screw 17. Therefore, the yoke 10 strengthens the ball 13 with the side bush 9 by the action of the elastic force of the bellows 15.
Hold it well.

Further, a cylindrical portion 1 is provided around the yoke 10.
0a is formed, and a permanent magnet 19 is provided inside the cylindrical portion 10a. In the permanent magnet 19, an N pole appears on the side of the bonding surface with the cylindrical portion 10a, which is the outside, and an S pole appears on the inside opposite thereto. An electromagnet 20 is fixed to the casing C, and the electromagnet 20 is opposed to the S pole side inside the permanent magnet. The electromagnet 20 is connected to a controller 22 via a connector 21. The controller 22 includes a vehicle speed sensor 23, a pressure sensor 24 for detecting a load pressure of a power cylinder, a lateral acceleration sensor 25 for detecting a lateral acceleration of the vehicle, and an adjustment volume 2 for adjusting a steering force gain.
6 are connected.

Next, the operation of the first embodiment will be described.
When the electromagnet 20 is not excited, the pressing force of the yoke 10 on the ball 13 is only the elastic force of the bellows 15, so that the pressing force hardly occurs. The steering reaction force at this time is only the torsional reaction force of the torsion bar 4, and the steering wheel operation feeling is relatively reduced. Therefore, the exciting current to the electromagnet 20 is not applied during low-speed running when the signal from the vehicle speed sensor 23 is equal to or lower than the certain speed. And as the vehicle speed gradually increases,
The controller 22 operates to increase the exciting current for the electromagnet 20. At this time, the direction of the current is controlled so as to generate a magnetic field such that the yoke 10 moves toward the side bush 9 according to the right-hand screw rule of ampere. Therefore, as the vehicle speed increases and the exciting current increases, the pressing force by the yoke 10 increases.

The stronger the pressing force of the yoke 10 is, the more the movement of the ball 13 in the inclined grooves 11 and 12 is restricted, so that the relative rotation between the input shaft 3 and the output shaft 2 becomes stronger. Power is needed. In other words, the steering operation feeling becomes heavy and the neutral rigidity is increased. Therefore, the running stability during high-speed running is improved. In the second embodiment shown in FIGS. 5 to 8, the inclined grooves 11 and 12 formed in the side bush 9 and the yoke 10 are provided with the wall surfaces 11a and 1a as in the first embodiment.
2a is not formed. However, if the side surfaces of the inclined grooves 11 and 12 are opened as described above, the stability of the ball 13 is impaired. Therefore, a plate-shaped retainer 27 for stabilizing the ball 13 is provided. Other configurations are the same as those of the first embodiment.

In the third embodiment shown in FIGS. 9 and 10, a disk-shaped leaf spring 28 is fixed to the yoke 10, and the inside of the leaf spring 28 is fixed to the input shaft 3.
9 fixed. And, this leaf spring 28 is
As shown in FIG. 7, a plurality of arc-shaped holes 30 are formed, and the elastic force thereof is adjusted. Incidentally, also in the second embodiment,
As in the first embodiment, the electromagnet 20 is provided on the yoke 10 and the exciting current for the electromagnet 20 is controlled based on a signal from the controller 22. The greatest feature of the third embodiment is that the yoke 1
Since there are no sliding parts on the zero, the frictional resistance is less,
The responsiveness is improved, and the use of a leaf spring enables a space saving to be realized as compared with the first embodiment using a bellows.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a perspective view of a side bush according to the first embodiment.

FIG. 3 is a perspective view of a yoke according to the first embodiment.

FIG. 4 is a side view of the first embodiment with a ball inserted between a side bush and a yoke.

FIG. 5 is a perspective view of a side bush according to a second embodiment.

FIG. 6 is a perspective view of a retainer according to a second embodiment.

FIG. 7 is a perspective view of a yoke according to a second embodiment.

FIG. 8 is a side view of the second embodiment with a ball inserted between a side bush and a yoke.

FIG. 9 is a sectional view of a main part of the third embodiment.

FIG. 10 is a front view of a retainer according to a third embodiment.

[Explanation of symbols]

 C casing 2 output shaft 3 input shaft 4 torsion bar 9 side bush 10 yoke 11 inclined groove 12 inclined groove 13 ball 19 permanent magnet 20 electromagnet 22 controller28 leaf spring 30 arc-shaped hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B62D 6/02 B62D 5/083

Claims (2)

(57) [Claims] 1. A power steering reaction device for providing an input shaft and an output shaft in a casing, and operating a power assist actuator by rotating the input shaft and the output shaft relative to each other. Fixed to the shaft
A leaf spring, a yoke fixed to the leaf spring and arranged in parallel to the axial direction of the input shaft, and a side bush fixed to the output shaft and provided opposite to the yoke, the plate spring is a disc-shaped, with its inner side is fixed to <br/> input shaft, the outer periphery is fixed to the yoke and to adjust the elastic force between these within the outer
In addition to forming holes, inclined grooves which gradually become shallower in the circumferential direction are formed at the same location on the circumference of the opposing surface of the yoke and the side bush, and a ball is interposed between these inclined grooves. further an electromagnet fixed to the casing, together with the above yoke secures the permanent magnet, these two magnets are opposed, moreover, the permanent magnet has one polarity to the opposite side of the electromagnet, its The other side has a polarity opposite to the facing surface, and a controller for controlling an exciting current of the electromagnet is provided, and the yoke is provided by exciting or not exciting the electromagnet.
Characterized in that the permanent magnet fixed to is moved, and the yoke is moved only in the axial direction of the input shaft.
Reaction device for power steering. To 2. electromagnet, when not applying an exciting current, the pressing force to the side bush side of the yoke is reduced by not generate an elastic force of the leaf spring itself to the yoke, was applied excitation current When the above-mentioned leaf spring bullet
The reaction force device for a power steering according to claim 1, wherein the pressing force of the yoke toward the side bush is increased by the sexual force .