JP3411191B2 - Power steering 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 system in which a motor performs power assist based on an input torque from a steering input shaft (generates an auxiliary driving force) and outputs a predetermined output torque to a steering output shaft. Regarding the device.

[0002]

2. Description of the Related Art A power steering device used in a vehicle (so-called
Among power steering devices), a device having a configuration in which a steering assist force (assist force) is generated by a motor is generally known (as one example, JP-A-6-171518).

In this power steering apparatus (electric power steering apparatus), in addition to a steering mechanism including a steering shaft and the like, a motor for generating a steering assist force is provided. This motor is connected to the steering shaft and is configured to be able to transmit drive torque. Further, a torsion bar is provided in the middle of the steering shaft, and a torque detection mechanism (torque sensor) is provided on the torsion bar. When the steering wheel is steered, this steering torque is detected by the torque detection mechanism, the motor is driven based on the detected steering torque, and the driving torque of the motor is transmitted to the steering shaft to obtain the steering assist force. It has become. In such an electric power steering device, the motor is driven according to the steering torque of the steering wheel, and the steering force can be favorably assisted.

However, in the conventional electric power steering apparatus disclosed in the above-mentioned publication, in order to control the motor in accordance with the steering torque of the steering wheel, there are components such as a torque sensor or a large motor controller which supplies a large current. Since this is an indispensable configuration, there is a drawback in that the system as a whole is large, complicated and costly.

Therefore, a power steering apparatus constructed by using a so-called print motor as a motor (electric motor) has been proposed (as an example, Japanese Patent Application No. 8-29468).

In this power steering apparatus, the print motor is composed of an armature and first and second magnetic pole pieces provided on both sides of the armature so as to face each other. When the steering input shaft is steered, the first magnetic pole piece and the second magnetic pole piece of the print motor face each other due to the rocking caused by the left and right rotations according to the magnitude of the input torque of the steering input shaft. Is relatively changed around the axis.

In this case, the facing positions of the first magnetic pole piece and the second magnetic pole piece are changed according to the magnitude of the input torque from the steering input shaft. Therefore, the magnetic flux density (magnetic field strength) of the print motor (first and second magnetic pole pieces and armature) changes according to the input torque. Therefore, the power assist force (motor driving force) output to the steering output shaft
Will increase or decrease in proportion to the magnitude of the input torque from the steering input shaft, and like the conventional power assist device, power assist based on the input torque from the steering input shaft will be performed to provide a predetermined output torque. Is output to the steering output shaft.

As described above, in the power steering apparatus described above,
It is possible to output the predetermined output torque corresponding to the steering torque of the steering wheel to the steering output shaft at a low cost with a simple structure to perform optimum power assist.

By the way, in the power steering apparatus constructed by using the print motor as described above, when the print motor is driven, a large inrush current flows through the print motor, and therefore the power is supplied to the print motor. There is a problem that the power supply brush is deteriorated or efficiency is reduced, and there is room for improvement in this respect.

[0010]

SUMMARY OF THE INVENTION In consideration of the above facts, the present invention can only output a predetermined output torque corresponding to the steering torque from the steering input shaft to the steering output shaft for optimum power assist. It is an object of the present invention to obtain a power steering apparatus that improves durability and efficiency of a power supply brush for supplying electric power.

[0011]

According to another aspect of the present invention, there is provided a power steering apparatus including a motor comprising an armature and a fixed magnetic pole piece and a movable magnetic pole piece which are provided on opposite sides of the armature. In the power steering apparatus, which performs power assist based on an input torque from a steering input shaft connected to a steering means and outputs a predetermined output torque to a steering output shaft for steering steered wheels, A magnetic pole piece control means for controlling the power assist force of the motor by relatively changing the facing positions of the fixed magnetic pole piece and the movable magnetic pole piece around the axis according to the magnitude of the input torque of the shaft, and to the motor. At the moment of energization of the motor, the inrush current reducing means for suppressing the inrush current to the motor by making the resistance higher than the resistance value at the time of steady driving of the motor,
Is a first armature, a first fixed pole piece, and a first movable magnet piece.
A first motor comprising a pole, a second armature and a second
A second motor consisting of a fixed pole piece and a second movable pole piece.
And a means for reducing the inrush current.
Is the first motor and the first motor during steady drive of the motor.
The moment when the motor is energized by connecting the two motors in parallel
The first motor and the second motor are connected in series to
That, it is characterized in that.

In the power steering apparatus according to the first aspect, the motor is connected to the steering output shaft connected to the steered wheels.
When the steering input shaft is steered, the motor is energized and the motor is driven. As a result, the driving force of the motor acts on the steering output shaft and is applied to the steering output shaft (steering wheels) as an auxiliary driving force. Therefore, the steering force of the steering input shaft (steering means) is reduced.

Here, in this power steering apparatus, the magnetic pole control means is operated according to the magnitude of the input torque of the steering input shaft. As a result, the facing positions of the fixed magnetic pole piece and the movable magnetic pole piece are relatively changed around the axis. In this case, the operation of the pole piece control means corresponds to the magnitude of the input torque from the steering input shaft, and the facing positions of the fixed pole piece and the movable pole piece are changed according to the magnitude of the input torque. It Therefore, the magnetic flux density (magnetic field strength) of the motor (fixed and movable magnetic pole pieces and armature) changes according to the input torque.
For this reason, the power assist force (motor driving force) output to the steering output shaft increases or decreases in proportion to the magnitude of the input torque from the steering input shaft, and like the conventional power assist device, Power assist based on the input torque from the steering input shaft can be performed to output a predetermined output torque to the steering output shaft.

Further, in this power steering apparatus, at the moment when the motor is energized, the resistance value is made higher than the resistance value during steady driving of the motor by the operation of the inrush current reducing means. Therefore, at this point (at the moment when the motor is energized), the inrush current to the motor is suppressed.
Therefore, the power supply brush that supplies power to the motor does not deteriorate or the efficiency does not decrease.

As described above, in the power steering apparatus according to the first aspect of the present invention, the predetermined output torque corresponding to the steering torque (of the steering means) from the steering input shaft is output to the steering output shaft for optimum power assist. Not only can this be done, but the durability and efficiency of the power supply brush for supplying power can be improved.

[0016]

[0017] In particular, in the power steering apparatus according to claim 1, wherein the motor is constituted by a first motor and the second motor, the steady drive of the motor and the first motor by the rush current reduction means The second motor is connected in parallel. Thereby, a predetermined output torque can be output to the steering output shaft.

On the other hand, at the moment when the motor is energized, the first motor and the second motor are connected in series by the inrush current reducing means. As a result, the resistance value of the entire motor circuit becomes higher than the resistance value during steady driving of the motor. Therefore, at this point (at the moment when the motor is energized), the inrush current to the motor is suppressed. Therefore, the power supply brush that supplies power to the motor does not deteriorate or the efficiency does not decrease.

[0019] Further, in the power steering apparatus of the first aspect, since the structure of the motor by the first motor and the second motor, in the case of ensuring the required driving force, a single motor Compared with, the inertia (moment of inertia) of the armature becomes smaller, and as a result, the responsiveness of the motor improves. Therefore, the auxiliary drive force can be quickly applied to the steering output shaft in response to the steering of the steering input shaft.

The power steering apparatus of the invention according to claim 2 is an electric power steering apparatus.
Fixed magnetic poles provided on both sides of the armature and the armature.
A steering means is provided by a motor including a child and a movable pole piece.
Based on the input torque from the steering input shaft connected to
Power assist to produce the specified output torque and turn the steered wheels.
The power steering device that outputs to the steering output shaft for steering
According to the magnitude of the input torque of the steering input shaft,
The position where the fixed magnetic pole piece and the movable magnetic pole piece face each other is relative to the axis.
To control the power assist force of the motor
At the moment of energizing the pole piece control means and the motor,
Make the resistance higher than the resistance value during steady driving of the motor
Inrush current to suppress the inrush current to the motor
A flow reducing means and a contact pressure of the power supply brush of the motor with respect to the armature are changeable, by making the contact pressure at the moment of energization of the motor lower than the contact pressure during steady driving of the motor, It is characterized by comprising a brush contact pressure changing means for increasing the contact resistance between the armature and the feeder brush.

In the power steering apparatus of the invention according to claim 2 ,
At the moment of energizing the motor, the contact pressure of the power supply brush with respect to the armature is made lower than the contact pressure during steady driving of the motor by the operation of the brush contact pressure changing means.
Therefore, at this time (at the moment when the motor is energized), the contact resistance between the power supply brush and the armature becomes large, and the inrush current to the motor is suppressed. Therefore, the power supply brush that supplies power to the motor does not deteriorate or the efficiency does not decrease.

[0022] Thus, in the power steering apparatus according to claim 2, wherein only can perform optimum power assist by outputting a predetermined output torque corresponding to the steering torque from the steering input shaft to the steering output shaft In addition, the durability and efficiency of the power supply brush for supplying power can be improved.

A power steering apparatus according to a third aspect of the present invention is the power steering apparatus according to the second aspect , wherein the brush contact pressure changing means is a solenoid.

In the power steering apparatus of the invention according to claim 3 ,
The structure is simple and the contact pressure of the power feeding brush can be changed reliably.

[0025]

1 to 3 are schematic sectional views showing the overall configuration of a power steering apparatus 10 according to an embodiment of the present invention.

The power steering apparatus 10 is used, for example, as an electric power steering apparatus for a vehicle and has an input shaft (steering shaft) 12. The input shaft 12 is arranged in a direction substantially orthogonal to the steered rod 24 serving as a steering output shaft, supported by a housing 194 by a bearing 192, and a steering wheel (not shown) serving as steering means is attached. Bearing 19 for supporting the input shaft 12
2 is a self-aligning type, and the input shaft 12 is the bearing 1
It can swing slightly with 92 as a fulcrum. A pinion 196 is provided on the input shaft 12 and meshes with a rack gear 198 of the rack bar 24 serving as a steering output shaft. A holding cylinder 200 is provided at the tip of the input shaft 12 so as to be movable to the left and right, and one end of a lever 202 is connected to the holding cylinder 200. Therefore, when the input shaft 12 slightly swings about the bearing 192 as a fulcrum, the lever 202 is moved along the longitudinal direction.

Further, the power steering apparatus 10 includes a motor unit 3
It is equipped with 4. The motor unit 34 is a so-called print motor, and includes a first motor unit 34A and a second motor unit 3
4B and.

The first motor section 34A includes the first armature 3
6 and a first fixed magnetic pole piece 38 and a first movable magnetic pole piece 40, which are provided on both sides of the first armature 36 so as to face each other. A motor rotation shaft 42 is fixed to the center of the first armature 36, and the motor rotation shaft 42 is rotatably supported by the housing 16. A gear 204 is provided on the motor rotating shaft 42 of the first armature 36, and is further connected to a rack gear 210 of the rack bar 24 via a reduction gear 206 and a pinion 208.

On the other hand, the first fixed magnetic pole piece 38 is fixed to the housing 16 so as to face the first armature 36. On the other hand, a holding plate 176 is attached to the first movable magnetic pole piece 40, and the holding plate 176 is supported so as to be rotatable relative to the motor rotation shaft 42. Therefore, the first
The movable magnetic pole piece 40 can rotate relative to the first fixed magnetic pole piece 38 relative to the first fixed magnetic pole piece 38 by rotating together with the holding plate 176.

On the other hand, the second motor section 34B includes a second armature 37, a second fixed magnetic pole piece 39 and a second movable magnetic pole piece provided on both sides of the second armature 37 so as to face each other. 41
It consists of and. A motor rotation shaft 42 is fixed to the center of the second armature 37 and rotates together with the first armature 36. On the other hand, the second fixed pole piece 39 is
It is fixed to the housing 16 so as to face the second armature 37. On the other hand, the second movable magnetic pole piece 41 is attached to the above-mentioned holding plate 176, so that the second movable magnetic pole piece 41 can rotate together with the holding plate 176 (that is, the first movable magnetic pole piece 40). Thus, the position facing the second fixed magnetic pole piece 39 can be relatively changed around the axis.

Further, the motor section 34 is provided with an operating mechanism section 211 as a magnetic pole control means. The actuating mechanism section 211 is provided with a gear 212.
12 is interlocked with the holding plate 176 of the first movable magnetic pole piece 40 and the second movable magnetic pole piece 41 described above. Further, a rack portion 203 formed at the other end of the lever 202 meshes with the gear 212. Therefore, the first movable magnetic pole piece 40 and the second movable magnetic pole piece 41 are rotationally moved by moving the lever 202 along the longitudinal direction.

A limit switch 214 is integrally provided on the actuating mechanism 211. The limit switch 214 has an operating contact 21 connected to the lever 202.
The steering state of the input shaft 12 (switching state between left and right) can be detected by moving 6 to the left and right to contact the fixed contacts 217 and 219. In the limit switch 214, fixed contacts 217 and 219 are connected to a power source, and an operating contact 216 is connected to the brush 76 and the brush 78 of the motor unit 34. Thus, the energization direction to the motor unit 34 (the first armature 36 and the second armature 37) can be switched according to the steering direction of the input shaft 12.

Here, FIG. 4A shows the configuration of the inrush current reducing means in a wiring circuit diagram of the motor section 34 (first motor section 34A and second motor section 34B).

Each of the brushes 76 and 78 of the first motor section 34A is connected to a power source.
A changeover switch SW ₁ is provided between the power supply and the power supply. On the other hand, each of the brushes 76 and 78 of the second motor unit 34B is also connected to a power source, and a changeover switch SW ₃ is provided between the brush 78 and the power source.
Further, the changeover switch S is provided between the brush 76 of the first motor unit 34A and the brush 78 of the second motor unit 34B.
W ₂ is provided.

Of these changeover switch SW ₁ , changeover switch SW ₂ and changeover switch SW ₃ , as shown in FIG. 4B, only changeover switch SW ₂ is turned on, and changeover switch SW ₁ and changeover switch SW ₃ are turned on. By being in the OFF state, the first motor unit 34A and the second motor unit 34A
B can be connected in series. On the other hand, the changeover switches SW ₁ and SW ₃ are turned on, and only the changeover switch SW ₂ is turned off.
The motor unit 34A and the second motor unit 34B can be connected in parallel. These changeover switch SW ₁ , changeover switch SW ₂ and changeover switch SW ₃ are
At the time of steady driving of the motor unit 34, the first motor unit 34A and the second motor unit 34B are connected in parallel, and at the moment when the motor unit 34 is energized, the first motor unit 34A and the second motor unit 34B are connected. Are connected in series.

Further, the brush 76 and the brush 78 of the motor section 34 are held by the holding mechanism section 50. Here, FIG. 5 shows a schematic configuration of the holding mechanism section 50 in a sectional view.

In the holding mechanism section 50, the brush 76 and the brush 78 are held by the holder 52 so as to be movable in the axial direction. A spring 54 is provided in the holder 52 and constantly urges the brush 76 and the brush 78 in the protruding direction. Further, the holder 52 is integrally provided with a solenoid 56 as a brush contact pressure changing means. The solenoid 56 includes an iron core portion 58 and a coil portion 6.
0, and the iron core portion 58 is a plate 62.
The spring 54 can be pressed via. That is, when the coil portion 60 is energized and the solenoid 56 is operated, the iron core portion 58 presses the spring 54 via the plate 62, and as a result, the first of the brush 76 and the brush 78.
The contact pressure with respect to the armature 36 and the second armature 37 is changed.

In this case, the solenoid 56 is energized to increase the contact pressure between the brush 76 and the brush 78 when the motor 34 is steadily driven, while the solenoid 56 is deenergized at the moment when the motor 34 is energized. Done, brush 7
6. The contact pressure of the brush 78 is set to be lower than the contact pressure of the motor unit 34 during steady driving.

Next, the operation of this embodiment will be described. In the power steering apparatus 10 having the above configuration, when the steering wheel (input shaft 12) is not steered (the vehicle is in a straight traveling state), the operating contact 216 of the limit switch 214 does not move, and the limit switch 214 is in the OFF state. Since it is maintained, the motor section 34 is not energized.

When the steering wheel (input shaft 12) is steered, the motor section 34 is operated according to the steering torque.

That is, when the input shaft 12 is steered to the left or right, the steering force of the input shaft 12 is passed through the pinion 196 and the rack gear 198 when turning to the right as shown by the arrow A direction in FIG. When transmitted to the rack bar 24, the rack bar 24 is driven in the axial direction (direction of arrow D) to steer the steered wheels.

In this case, immediately after the steering of the input shaft 12, the resistance of the rack bar 24 (that is, the tire side) is large, so that the rack bar 24 does not move. Therefore, the input shaft 12 slightly moves around the bearing 192 as a fulcrum. Rock. Therefore, the swing of the input shaft 12 moves the lever 202 along the longitudinal direction, and the first movable magnetic pole piece 40 and the second movable magnetic pole piece 41 are rotated. As a result, the facing position of the first fixed magnetic pole piece 38 and the first movable magnetic pole piece 40 and the facing position of the second fixed magnetic pole piece 39 and the second movable magnetic pole piece 41 are relatively arranged around the axis. Changed, the polarity of each pole piece is from the same pole state (N pole-N pole state or S pole-S pole state) to different pole state (N pole-S pole state or S pole-N pole state)
Gradually changed to.

Further, at this time, the operating contact 216 of the limit switch 214 moves along with the movement of the lever 202, the limit switch 214 is turned on, and the motor section 34 is turned on.
(First armature 36, second armature 37) is energized,
The first armature 36 and the second armature 37 of the motor unit 34
Rotates.

As a result, the driving force of the motor section 34 acts on the rack bar 24 to which the motor rotation shaft 42 is connected, and is applied as an auxiliary driving force. Therefore, the input shaft 12
The steering force of (steering wheel) is reduced.

On the other hand, when the input shaft 12 is steered to the left (the direction of arrow C in FIG. 1), the steering force of the input shaft 12 is increased by the pinion 1.
It is transmitted to the rack bar 24 via 96 and the rack gear 198, the rack bar 24 is driven in the axial direction (direction of arrow B), and the steered wheels are steered.

In this case as well, immediately after the steering of the input shaft 12, the rack bar 24 (ie, the tire side) has a large resistance, so that the rack bar 24 does not move. Therefore, the input shaft 12 uses the bearing 192 as a fulcrum. It rocks slightly. Therefore, the tip of the input shaft 12 swings, the lever 202 moves along the longitudinal direction, and the first movable magnetic pole piece 40 and the second movable magnetic pole piece 41 rotate. This allows
The position where the first fixed magnetic pole piece 38 and the first movable magnetic pole piece 40 face each other, and the second fixed magnetic pole piece 39 and the second movable magnetic pole piece 4
The position facing 1 is relatively changed around the axis, and the polarities of the respective magnetic poles are gradually changed from the same-polarity state to the different-polarity state.
Further, at this time, as the lever 202 moves, the operating contact 216 of the limit switch 214 moves in the opposite direction to the above, the limit switch 214 is turned on, and the motor unit 34
The first armature 36 and the second armature 37 are energized to energize the first armature 36 and the second armature 37 of the motor unit 34.
Rotates in the opposite direction to the above.

As a result, the driving force of the motor section 34 acts on the rack bar 24 to which the motor rotation shaft 42 is connected, and is applied as an auxiliary driving force. Therefore, the input shaft 12
The steering force of (steering wheel) is reduced.

In this case, the first movable magnetic pole piece 40 and the second movable magnetic pole piece 40
Lever 20 for connecting the movable magnetic pole piece 41 and the input shaft 12
The movement of 2 corresponds to the magnitude of the input torque from the input shaft 12, and the position where the first fixed magnetic pole piece 38 and the first movable magnetic pole piece 40 face each other and the second fixed magnetic pole piece 39 The position facing the second movable magnetic pole piece 41 is changed in accordance with the magnitude of the input torque. Therefore, the driving force of the motor unit 34 increases or decreases according to the input torque, and similar to the conventional hydraulic power steering apparatus, power assist based on the input torque from the input shaft 12 is performed to perform a predetermined operation. Output torque can be applied to the rack bar 24.

The steering wheel (input shaft 1
2) is switched to the left or right, the direction of energization of the motor portion 34 to the first armature 36 and the second armature 37 is switched by operating the lever 202 and the limit switch 214 as described above. The rotation direction of the rotary shaft 42 is switched to correspond to the steering direction of the input shaft 12.

Here, in the power steering apparatus 10, the motor section 34 is composed of the first motor section 34A and the second motor section 34B, and when the motor section 34 is steadily driven, the changeover switch SW ₁ and the changeover switch SW _{1 are changed over} . The switch SW ₂ and the changeover switch SW ₃ are switched as shown in FIG. 4B, and the first motor unit 34A and the second motor unit 34B are connected in parallel. Further, during steady driving of the motor section 34, the solenoid 56 is energized to increase the contact pressure between the brush 76 and the brush 78, and the brush 76 and the brush 7 are contacted.
8, the contact resistance between the first armature 36 and the second armature 37 becomes small. Therefore, the motor unit 34 generates a predetermined driving force and outputs a predetermined output torque to the rack bar 24.
Can be output to.

On the other hand, at the moment when the motor section 34 is energized,
The changeover switch SW ₁ , the changeover switch SW ₂ , and the changeover switch SW ₃ are changed over as shown in FIG. 4B, and the first motor section 34A and the second motor section 34B are connected in series. As a result, the resistance value of the entire wiring circuit of the motor unit 34 becomes higher than the resistance value of the motor unit 34 during steady driving. Therefore, at this point (at the moment of energizing the motor unit 34), the inrush current to the motor unit 34 is suppressed. Therefore, the brush 76 and the brush 78 that supply electric power to the motor unit 34 (the first armature 36 and the second armature 37) do not deteriorate or the efficiency does not decrease.

Furthermore, in the power steering apparatus 10, at the moment when the motor section 34 is energized, the solenoid 56 is de-energized, and the contact pressure between the brush 76 and the brush 78 becomes
The pressure is set to be lower than the contact pressure during steady driving of the motor unit 34. Therefore, at this time (at the moment when the motor unit 34 is energized), the contact resistance between the brush 76 and the brush 78 and the first armature 36 and the second armature 37 increases, and the motor unit 34 The inrush current to is suppressed. Therefore, this also reduces the deterioration of the brushes 76 and 78.

As described above, the power steering apparatus 10 according to the present embodiment can only output a predetermined output torque corresponding to the steering torque of the steering wheel to the steering output shaft for optimum power assist. In addition, the durability and efficiency of the brush 76 and the brush 78 for supplying electric power can be improved.

Furthermore, in the power steering apparatus 10, the motor unit 34 is replaced by the first motor unit 34A and the second motor unit 34.
In order to secure a necessary driving force, the inertia (inertia moment) of the armature (the first armature 36 and the second armature 37) is larger than that of a single motor because it is composed of B and B. Becomes smaller, and as a result, the responsiveness of the motor unit 34 improves. Therefore, the auxiliary driving force can be quickly applied to the rack bar 24 in response to the steering of the input shaft 12.

In the present embodiment, the brush 7
6 and the brush 78 have been described as having a general configuration, but the configuration is not limited to this, and a configuration using a carbon pile whose resistance value changes according to a pressing force, such as the brush 80 shown in FIG. 6, may be used. In this case, the inrush current to the motor unit 34 can be suppressed more effectively, and the deterioration of the brush 80 can be reduced.

Further, in the above-described embodiment, the contact pressure of the brush 76 and the brush 78 is changed to change the contact pressure between the brush 76 and the brush 78, the first armature 36 and the second armature 37.
Although the contact resistance between and is increased to suppress the inrush current to the motor unit 34, another new power supply brush may be provided.

That is, as shown in FIG. 7, the brush 82 whose resistance value is set small is replaced with the brush 76 and the brush 78.
Separately from the above, the first armature 36 and the second armature 37 are provided so as to be in contact / non-contact with each other. In this case, at the moment when the motor section 34 is energized, the solenoid 56 is de-energized, and the brush 82 is separated from the first armature 36 and the second armature 37 and is in a non-contact state. It is said that Therefore, at this time (at the moment of energizing the motor unit 34), the resistance between the brush 76 and the brush 78 and the first armature 36 and the second armature 37 becomes large as a whole, and the motor unit Inrush current to 34 is suppressed, and brush 76
Also, the deterioration of the brush 78 can be reduced.

Further, in the above-described embodiment, the solenoid 56 is provided as the brush contact pressure changing means, and the contact pressure of the brush 76 and the brush 78 is changed by the solenoid 56, but the present invention is not limited to this.
For example, the contact pressure of the brush 76 and the brush 78 may be changed by another moving source such as a hydraulic cylinder.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of a power steering apparatus according to an embodiment of the present invention, as viewed from the front side.

FIG. 2 is a cross-sectional view showing the overall configuration of the power steering apparatus according to the embodiment of the present invention as viewed from the back side.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1 showing the configuration of the motor section of the power steering apparatus according to the embodiment of the present invention.

FIG. 4 shows a configuration of an inrush current reducing means of the power steering apparatus according to the embodiment of the present invention, (A) is a wiring circuit diagram of a motor section (first motor section and second motor section). Yes,
(B) is a correspondence diagram showing the ON / OFF relationship of the changeover switch.

FIG. 5 is a cross-sectional view showing a configuration of a holding mechanism portion of the power steering apparatus according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view showing another example of the brush held by the holding mechanism portion of the power steering apparatus according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view showing another example of the brush held by the holding mechanism portion of the power steering apparatus according to the embodiment of the present invention.

[Explanation of symbols]

10 power steering device 12 input shaft (steering input shaft) 24 rack bar (steering output shaft) 34 motor unit 34A first motor unit 34B second motor unit 36 first armature 37 second armature 38 First fixed magnetic pole piece 39 Second fixed magnetic pole piece 40 First movable magnetic pole piece 41 Second movable magnetic pole piece 50 Holding mechanism section 52 Holder 54 Spring 56 Solenoid (brush contact pressure changing means) 58 Iron core section 60 Coil section 76 Brush 78 Brush 80 Brush 82 Brush 202 Lever 211 Actuating Mechanism (Magnet Control Unit) 214 Limit Switch SW ₁ Changeover Switch (Inrush Current Reduction Means) SW ₂ Changeover Switch (Inrush Current Reduction Means) SW ₃ Changeover Switch (Inrush Current) (Reduction means)

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Hasegawa 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor Shuji Fujita 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (( 56) References JP-A-7-101345 (JP, A) JP-A-10-4667 (JP, A) JP-A-9-240497 (JP, A) German Patent Application Publication 19642396 (DE, A 1) ( 58) Fields surveyed (Int.Cl. ⁷ , DB name) B62D 5/04 B62D 6/00

Claims (3)

(57) [Claims] 1. A power based on an input torque from a steering input shaft connected to a steering means by a motor composed of an armature and a fixed magnetic pole and a movable magnetic pole provided on opposite sides of the armature. A power steering apparatus for assisting to output a predetermined output torque to a steering output shaft for steering steered wheels, comprising: a fixed magnetic pole and a movable magnetic pole according to a magnitude of an input torque of the steering input shaft. A pole piece control means for relatively changing the position facing the child around the axis to control the power assist force of the motor, and a resistance value at the moment of energization of the motor, which is higher than the resistance value during steady driving of the motor. by a high resistance, and a rush current reduction means for suppressing the inrush current to the motor, the motor is first armature and the first fixed Jikyokuko and first magnet armature
A first motor consisting of, a second armature and a second fixed
Second motor including a magnetic pole piece and a second movable magnetic pole piece
And the inrush current reducing means is configured to drive the first motor and the second motor during steady driving of the motor.
Connect the motor in parallel, and at the moment of energizing the motor,
A power steering apparatus, wherein the first motor and the second motor are connected in series . 2. The armature and the armature are provided so as to face each other on both sides of the armature.
For a motor consisting of a fixed magnetic pole piece and a movable magnetic pole piece
Therefore, the input torque from the steering input shaft connected to the steering means is
Perform power assist based on the torque
Output to the steering output shaft for steering the steered wheels.
In the power steering device, the fixed state is set according to the magnitude of the input torque of the steering input shaft.
The position where the magnetic pole piece and the movable magnetic pole piece face each other is relatively set around the axis.
Magnetic poles that change and control the power assisting force of the motor
During normal operation of the motor at the moment when the motor is energized
By setting the resistance higher than the resistance value in
Inrush current reducing means for suppressing inrush current to the motor, and contact pressure of the power supply brush of the motor with respect to the armature
It is provided so that it can be changed at the moment of energizing the motor.
Set the pressure lower than the contact pressure during steady driving of the motor.
The contact between the power supply brush and the armature.
Power steering apparatus for a brush contact pressure changing means for increasing the tactile resistance, comprising the. 3. The brush contact pressure changing means is a solenoid.
The power steering apparatus according to claim 2, wherein the power steering apparatus is a switch.