JP3537301B2 - 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. Related to the device.

[0002]

2. Description of the Related Art In an electric power steering apparatus using a motor, means for changing a power supply frequency and a power supply voltage is used to control an output generated by the motor. Circuits were indispensable and costly. Therefore, a so-called actual air gap type electric motor capable of solving such a drawback has been proposed (for example, Japanese Patent Application Laid-Open No. 53-47908).

[0003] In this electric motor, there are provided first and second stators having windings through which an alternating current is passed, and a rotor is disposed between the first and second stators. Further, the opposed positions of the first and second stators can be relatively changed by manual adjustment. According to this electric motor, the phase of the torque generated by the first stator and the rotor and the phase of the torque generated by the second stator and the rotor are changed by manually changing the opposing positions of the first and second stators. (Variable phase type), whereby the output torque of the rotor (rotating shaft) can be adjusted to obtain an arbitrary output. Therefore, an electronic circuit or the like having a complicated configuration for torque control is not required, and the cost is reduced with a simple structure.

[0004] In a vehicle power steering apparatus (power steering), it is desirable to change the power assist force in accordance with a vehicle running state such as a vehicle speed and a steering angle. In this regard, the electric motor disclosed in the above publication has a configuration in which the output torque of the rotor (rotating shaft) is adjusted by manually moving the first or second stator. In the power steering device, the power assisting force cannot be changed according to the input torque from the steering input shaft or the vehicle speed or the steering angle. There was a drawback that it was not possible to output to the steering output shaft.

[0005] Further, in this type of power steering apparatus (power steering), not only can suitable power assist be performed, but also a good steering feeling (so-called, when the steering wheel returns to the neutral position). It is also important that a neutral feeling can be obtained.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present invention provides a power steering apparatus capable of outputting a predetermined output torque corresponding to a running state of a vehicle to a steering output shaft to perform optimal power assist. It is another object of the present invention to provide a power steering device capable of obtaining a good steering feeling (neutral feeling) when the steering wheel returns to a neutral position after power assist.

[0007]

According to a first aspect of the present invention, there is provided a power steering apparatus comprising a motor comprising an armature and first and second magnetic poles provided on both sides of the armature. A power steering device that 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 a steered wheel; An energization switching mechanism that switches an energization direction to the power supply brush of the motor in accordance with the left and right rotation directions of the input shaft; and the first magnetic pole and the second magnetic pole in accordance with the magnitude of input torque from the steering input shaft. Magnetic pole control means for relatively changing the position facing the magnetic pole around the axis and controlling the power assisting force of the motor;
A show that contacts the armature and partially shorts the armature coil
Electrical connection between the brush and the short brush
According to the running state of the vehicle.
Output torque control means for changing an electric resistance value of the variable resistor and controlling a power assisting force of the motor.

[0008]

[0009]

[0010]

[0011]

[0012]

[0013] In the power steering apparatus according to the first aspect, the motor is connected to a steering input shaft to which steering means such as a steering wheel is attached, and a steering output shaft connected to steered wheels. When the steering input shaft is steered, the energization switching mechanism operates to energize the motor and drive the motor. As a result, the driving force of the motor acts on the steering output shaft, and is applied to the steering output shaft (steered wheels) as an auxiliary driving force. Therefore, the steering force of the steering input shaft (steering means) is reduced. Further, when the steering input shaft is switched between left and right, the direction of energization of the motor is switched by the current switching mechanism, and the rotation direction of the steering output shaft is switched, so that the steering direction of the steering input shaft can be coped with.

Here, when the steering input shaft is steered,
The magnetic pole control means operates in accordance with the input torque from the steering input shaft, and the facing position between the first magnetic pole and the second magnetic pole is relatively changed around the axis. In this case, the operation of the magnetic pole control means corresponds to the magnitude of the input torque from the steering input shaft, and the facing position between the first magnetic pole and the second magnetic pole corresponds to the magnitude of the input torque. Changed. Therefore, the magnetic flux density (magnetic field intensity) of the motor (the first and second magnetic poles and the armature) changes according to the input torque. For this reason, the power assisting force (motor driving force) output to the steering output shaft increases and decreases in proportion to the magnitude of the input torque from the steering input shaft, and like the conventional power assist device, A predetermined output torque can be output to the steering output shaft by performing power assist based on the input torque from the steering input shaft.

Further, in this power steering device, the output torque control means operates in accordance with the running state of the vehicle, and the electric resistance value of the variable resistor connected between the short brushes changes. Is done. This allows the carp between the short brushes
The magnetic flux generated by the motor changes, and the driving force of the motor increases or decreases. That is, by changing the electric resistance value of the variable resistor according to the running state of the vehicle, the power assist force (motor driving force) output to the steering output shaft increases or decreases in accordance with the running state of the vehicle. As a result, power assist based on the running state of the vehicle can be performed, and a predetermined output torque can be output to the steering output shaft.

[0016] Thus, in the power steering apparatus according to claim 1, wherein the output torque control means according to the vehicle running state is actuated, electric variable resistor connected between the short brushes
By changing the air resistance value, the drive control of the motor according to the vehicle running state is performed, and the steering force can be favorably assisted. Further, the structure is simple, so that the cost and the size and weight can be significantly reduced.

[0017]

[0018]

[0019]

[0020]

[0021]

According to a second aspect of the present invention, in the power steering apparatus according to the first aspect , the output torque control means is connected to the variable resistor and rotatably supported. And a control motor connected to the movement gear and driven to rotate the movement gear.

In the power steering apparatus according to the second aspect , the moving gear is rotated by driving the control motor, thereby changing the electric resistance value of the variable resistor. Therefore, if the control motor is driven according to the vehicle traveling state such as the vehicle speed and the steering angle, the power assist force can be changed according to the vehicle traveling state such as the vehicle speed and the steering angle.

[0024] Thus, in the power steering apparatus according to the second aspect, by a simple structure, it is possible to perform good power assist in response to vehicle running state.

According to a third aspect of the present invention, there is provided a power steering apparatus according to the first or second aspect , further comprising a vehicle speed signal generating means for generating a vehicle speed signal based on a running speed of the vehicle, and The output torque control means controls the power assist force of the motor based on a vehicle speed signal from the vehicle speed signal generation means.

In the power steering apparatus according to the third aspect , the output torque control means operates based on the vehicle speed signal from the vehicle speed signal generation means. Therefore, favorable power assist according to the vehicle speed can be performed.

According to a fourth aspect of the present invention, the power steering apparatus is connected to the steering means by a motor comprising an armature and first and second magnetic poles provided on both sides of the armature. A power steering device that performs power assist based on an input torque from a steering input shaft to output a predetermined output torque to a steering output shaft for steering a steered wheel;
An energization switching mechanism for switching the energization direction to the power supply brush of the motor according to the left and right rotation directions of the steering input shaft;
A magnetic pole for controlling a power assist force of the motor by relatively changing a facing position between the first magnetic pole and the second magnetic pole around an axis in accordance with the magnitude of an input torque from the steering input shaft. Control means, for one of the first magnetic pole and the second magnetic pole whose facing position is changed by the magnetic pole control means, the one magnetic pole at a neutral position of the steering means; And an auxiliary magnet having a different polarity and provided opposite to the one magnetic pole.

In the power steering apparatus according to the fourth aspect , the motor is connected to a steering input shaft on which steering means such as a steering wheel is attached, and a steering output shaft connected to steered wheels. When the steering input shaft is steered, the energization switching mechanism operates to energize the motor and drive the motor. As a result, the driving force of the motor acts on the steering output shaft, and is applied to the steering output shaft (steered wheels) as an auxiliary driving force. Therefore, the steering force of the steering input shaft (steering means) is reduced. Further, when the steering input shaft is switched between left and right, the direction of energization of the motor is switched by the current switching mechanism, and the rotation direction of the steering output shaft is switched, so that the steering direction of the steering input shaft can be coped with.

Here, when the steering input shaft is steered,
The magnetic pole control means operates in accordance with the input torque from the steering input shaft, and the facing position between the first magnetic pole and the second magnetic pole is relatively changed around the axis. In this case, the operation of the magnetic pole control means corresponds to the magnitude of the input torque from the steering input shaft, and the facing position between the first magnetic pole and the second magnetic pole corresponds to the magnitude of the input torque. Changed. Therefore, the magnetic flux density (magnetic field intensity) of the motor (the first and second magnetic poles and the armature) changes according to the input torque. For this reason, the power assisting force (motor driving force) output to the steering output shaft increases and decreases in proportion to the magnitude of the input torque from the steering input shaft, and like the conventional power assist device, A predetermined output torque can be output to the steering output shaft by performing power assist based on the input torque from the steering input shaft.

Further, in this power steering apparatus, the neutralization of the steering means is performed with respect to one of the first magnetic pole and the second magnetic pole whose facing position is changed by the magnetic pole control means. An auxiliary magnet having a different position from the one magnetic pole at a position is provided to face the one magnetic pole.

Therefore, even if the first magnetic pole and the second magnetic pole face each other in the same polar state at the neutral position of the steering means, the one magnetic pole attracts the auxiliary magnet and
As a result, it is possible to stably return to the neutral position. Therefore,
When the steering means returns to the neutral position, a good steering feeling (neutral feeling) is obtained.

As described above, in the power steering apparatus according to the fourth aspect , the power assist based on the input torque from the steering input shaft is performed, and a predetermined output torque is output to the steering output shaft to perform the optimal power assist. Not only can it be performed, but also a good steering feeling (neutral feeling) can be obtained when the steering means returns to the neutral position after power assist, and this can be realized with a simple structure.

According to a fifth aspect of the present invention, the power steering apparatus is connected to the steering means by a motor comprising an armature and first and second magnetic poles provided on both sides of the armature. A power steering device that performs power assist based on an input torque from a steering input shaft to output a predetermined output torque to a steering output shaft for steering a steered wheel;
An energization switching mechanism for switching the energization direction to the power supply brush of the motor according to the left and right rotation directions of the steering input shaft;
A magnetic pole for controlling a power assist force of the motor by relatively changing a facing position between the first magnetic pole and the second magnetic pole around an axis in accordance with the magnitude of an input torque from the steering input shaft. A control means, and an auxiliary magnet part partially provided in one of the first and second magnetic poles and having a polarity different from that of the other magnetic pole facing the neutral position of the steering means. And, it is characterized by having.

In the power steering apparatus according to the fifth aspect , the motor is connected to a steering input shaft to which steering means such as a steering wheel is attached, and a steering output shaft connected to steered wheels. When the steering input shaft is steered, the energization switching mechanism operates to energize the motor and drive the motor. As a result, the driving force of the motor acts on the steering output shaft, and is applied to the steering output shaft (steered wheels) as an auxiliary driving force. Therefore, the steering force of the steering input shaft (steering means) is reduced. Further, when the steering input shaft is switched between left and right, the direction of energization of the motor is switched by the current switching mechanism, and the rotation direction of the steering output shaft is switched, so that the steering direction of the steering input shaft can be coped with.

Here, when the steering input shaft is steered,
The magnetic pole control means operates in accordance with the input torque from the steering input shaft, and the facing position between the first magnetic pole and the second magnetic pole is relatively changed around the axis. In this case, the operation of the magnetic pole control means corresponds to the magnitude of the input torque from the steering input shaft, and the facing position between the first magnetic pole and the second magnetic pole corresponds to the magnitude of the input torque. Changed. Therefore, the magnetic flux density (magnetic field intensity) of the motor (the first and second magnetic poles and the armature) changes according to the input torque. For this reason, the power assisting force (motor driving force) output to the steering output shaft increases and decreases in proportion to the magnitude of the input torque from the steering input shaft, and like the conventional power assist device, A predetermined output torque can be output to the steering output shaft by performing power assist based on the input torque from the steering input shaft.

In this power steering apparatus, one of the first magnetic pole and the second magnetic pole has a polarity opposite to that of the other magnetic pole facing the neutral position of the steering means. However, an auxiliary magnet part different from the above is partially provided.

For this reason, even if the first magnetic pole and the second magnetic pole face each other in the same polarity state at the neutral position of the steering means, the auxiliary magnet portion of one of the magnetic poles is in contact with the other magnetic pole. As a result, they can stably return to the neutral position. Therefore, a good steering feeling (neutral feeling) can be obtained when the steering means returns to the neutral position.

As described above, in the power steering apparatus according to the fifth aspect , the power assist based on the input torque from the steering input shaft is performed, and a predetermined output torque is output to the steering output shaft to perform the optimal power assist. Not only can it be performed, but also a good steering feeling (neutral feeling) can be obtained when the steering means returns to the neutral position after power assist, and this can be realized with a simple structure.

[0039]

1 to 3 schematically show a power steering apparatus 10 according to a first embodiment of the present invention in a schematic sectional view.

The power steering device 10 is used, for example, as an electric power steering device for a vehicle, and has an input shaft (steering shaft) 12. The input shaft 12 is arranged in a direction substantially perpendicular to the rack bar 24 as a steering output shaft, is supported by a housing 194 by bearings 192, and has a steering wheel (not shown) as steering means. The bearing 192 supporting the input shaft 12 is of a self-centering type, and the input shaft 12 can slightly swing about the bearing 192 as a fulcrum. Input shaft 1
2 is provided with a pinion 196, which meshes with a rack gear 198 of a rack bar 24 as a steering output shaft. At the tip of the input shaft 12, there is provided a holding cylinder 200 which can move to the left and right corresponding to this. Further, the holding cylinder 200 has a lever 20 as a connecting member.
2 are connected at one end. Therefore, when the input shaft 12 slightly swings around the bearing 192, the lever 202 is moved in the longitudinal direction.

Further, the power steering device 10 includes the motor unit 3
4 is provided. The motor unit 34 is a so-called print motor, and includes an armature 36 housed in the housing 16.
And a first magnetic pole 38 and a second magnetic pole 40 provided on both sides of the armature 36 to face each other.
A motor rotation shaft 42 is fixed to the center of the armature 36, and the motor rotation shaft 42 is rotatably supported by the housing 16. A gear 204 is provided on the motor rotation shaft 42 of the armature 36.
And a rack gear 210 of the rack bar 24 via a pinion 208.

On the other hand, the first magnetic pole 38 is fixed to the housing 16 so as to face the armature 36. On the other hand, a holding plate 176 is attached to the second pole piece 40, and a shaft 178 fixed to the holding plate 176 is rotatably supported by the housing 16. For this reason, by rotating the second magnetic pole 40 together with the holding plate 176, the position facing the first magnetic pole 38 can be relatively changed around the axis. A gear 212 is provided on the shaft 178 of the holding plate 176, and the gear 212
02 is engaged with a rack portion 203 formed at the other end. Therefore, when the lever 202 is moved in the longitudinal direction, the holding plate 176, that is, the second magnetic pole element 4 is moved.
0 is a configuration that is rotationally moved.

The lever 202 (that is, the input shaft 1)
2) In the neutral state, the polarities of the first magnetic pole 38 and the second magnetic pole 40 are the same (N pole-N pole state or S pole state).
(Pole-S pole state), the length dimension of the lever 202 and the like are set.

The motor unit 34 is provided integrally with a limit switch 214 as an energization switching mechanism. The limit switch 214 can detect a steering state (a left-right switching state) of the input shaft 12 when an operating contact 216 provided on a shaft 178 moves left and right to contact fixed contacts 217 and 219. I have. The limit switch 214 is connected to a brush 76 and a brush 78 of the motor unit 34, which will be described in detail later.
The direction of energization to the motor unit 34 (armature 36) can be switched according to the steering direction of the input shaft 12.

Further, the brush 76 and the brush 78 of the motor section 34 are connected to the moving mechanism section 50 as output torque control means.
Is held by Here, FIG. 4 shows a schematic configuration of the moving mechanism unit 50 in a cross-sectional view along line 4-4 in FIG.

The moving mechanism section 50 is provided with a moving gear 52. The moving gear 52 is formed in a hollow shape and is positioned coaxially with the shaft 178. The moving gear 52 is rotatably held by a gear holder 54 press-fitted into the housing 16 of the motor unit 34 via a bearing 56. A through hole 58 is formed in the gear holder 54, and a holding portion 60 that protrudes radially outward is formed in the moving gear 52 corresponding to the through hole 58.

The moving mechanism 50 includes a brush 76,
A brush 78 is provided. One brush 76 is a fixed brush and is fixed to the gear holder 54. On the other hand, the other brush 78 is a moving brush, which is located in the through hole 58 of the gear holder 54 and whose brush holder 80 is attached to the holding portion 6 of the moving gear 52.
It is connected and fixed to 0. Thereby, the moving gear 52
Is rotated, the brush 78 is moved, and the armature 36
This is a configuration that can change the contact state with respect to.

One end of a spring 82 is connected to the brush holder 80 of the brush 78, and the other end of the spring 82 is connected to the gear holder 54. This allows
The brush 78 (that is, the moving gear 52) is urged to always return to a predetermined position.

Further, the gear holder 54 of the moving mechanism 50
, A control motor 84 is attached. The output gear 86 of the control motor 84 meshes with the movement gear 52. Therefore, when the control motor 84 is driven, the movement gear 52 can be rotated.

The control motor 84 is connected to a power supply and to a motor drive circuit 88. Further, a motor speed detection signal is input from a vehicle speed sensor 89 to the motor drive circuit 88. Accordingly, the control motor 84 operates according to the traveling speed of the vehicle, and can rotate the moving gear 52.

Next, the operation of the first embodiment will be described. In the power steering device 10 having the above configuration, when the steering wheel (the input shaft 12) is not steered (the vehicle is in a straight running state), the operating contact 216 of the limit switch 214 is not moving, and the limit switch 214 is in the OFF state. The motor section 34 is not energized.

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

That is, when the input shaft 12 is steered in either the left or right direction, for example, when turning right as shown by the arrow A in FIG. 1, the steering force of the input shaft 12 is transmitted via the pinion 196 and the rack gear 198. The power is transmitted to the rack bar 24, and the rack bar 24 is driven in the axial direction (the direction of arrow D) to steer the steered wheels.

In this case, immediately after the steering of the input shaft 12, the rack bar 24 (that is, the tire side) has a large resistance because the resistance of the rack bar 24 is large, so that the input shaft 12 is slightly moved around the bearing 192 as a fulcrum. Rocks. Therefore, the swing of the input shaft 12 causes the lever 202 to move in the longitudinal direction, and the second magnetic pole element 40 to rotate.
Thereby, the facing position of the first magnetic pole 38 and the second magnetic pole 40 is relatively changed around the axis, and the polarity of each magnetic pole is in the same polarity state (N pole-N pole state or S pole). (−S pole state) to a different pole state (N pole−S pole state or S pole−N pole state).

Further, at this time, the operating contact 216 of the limit switch 214 moves in accordance with the movement of the lever 202, and the limit switch 214 is turned on to turn on the motor unit 34.
(Armature 36), and the armature 36 of the motor unit 34 is energized.
Rotates.

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

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

Also in this case, immediately after the input shaft 12 is steered, the rack bar 24 (that is, the tire side) has a large resistance so that the rack bar 24 does not move. Therefore, the input shaft 12 is supported by the bearing 192 as a fulcrum. Swings slightly. Therefore, the tip of the input shaft 12 swings, the lever 202 is moved along the longitudinal direction, and the second magnetic pole element 40 is rotated. Thereby, the opposing positions of the first magnetic pole piece 38 and the second magnetic pole piece 40 are relatively changed around the axis, and the polarity of each magnetic pole piece is gradually changed from the same polarity state to the different polarity state. Further, at this time, the operating contact 216 of the limit switch 214 moves in the opposite direction to the above with the movement of the lever 202, and the limit switch 214 is turned on, so that the motor unit 34 (armature 36) is energized and The armature 36 of 34 rotates in the opposite direction to that described above.

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

In this case, the second magnetic pole 40 and the input shaft 12
The movement of the lever 202 for connecting the first magnetic pole 38 corresponds to the magnitude of the input torque from the input shaft 12.
The opposing position of the second magnetic pole 40 is changed according to the magnitude of the input torque. Therefore, the driving force of the motor unit 34 increases and decreases according to the input torque, and performs power assist based on the input torque from the input shaft 12 to reduce the predetermined output torque, as in the conventional power steering device. It can be applied to the rack bar 24.

The steering wheel (input shaft 1)
When 2) is switched between left and right, the direction of energizing the armature 36 of the motor unit 34 is switched by the operation of the lever 202 and the limit switch 214 as described above, and the rotation direction of the motor rotating shaft 42 is switched. Input shaft 12
It can respond to the steering direction.

Further, in the power steering device 10, the moving mechanism 50 operates according to the traveling speed of the vehicle, and the power assisting force applied to the rack bar 24 can be changed according to the vehicle speed.

That is, when the vehicle speed is zero (stop state), the control motor 84 does not generate a driving force.
Therefore, the brush 78 (brush holder 80) is positioned at one end of the through hole 58 of the gear holder 54 by the urging force of the spring 82.

When the vehicle is in a running state, a vehicle speed detection signal is input to a motor drive circuit 88, so that the control motor 84 operates according to the running speed of the vehicle. By the operation of the control motor 84, the moving gear 52 is rotated, and one brush 78 of the motor unit 34 is moved by the moving gear 52.
At the same time, it rotates against the urging force of the spring 82, and stops at a position where the driving force of the control motor 84 and the urging force of the spring 82 are balanced. Thereby, the armature 36 of the brush 78
Is changed. Thereby, the armature 3
The effective length (the number of effective conductors) of the six coils is changed, and the driving force of the motor unit 34 is reduced.

The biasing force of the spring 82 is set so that the brush 78 is balanced at a position where an optimum power assist force is obtained.

Further, when the vehicle speed increases, the vehicle speed detection signal input to the motor drive circuit 88 changes.
The drive voltage to the control motor 84 rises and the control motor 84
Is further driven, and stops at a position where the driving force at that time and the urging force of the spring 82 are balanced. Thereby, the armature 3
The effective length (the number of effective conductors) of the six coils is further changed, and the driving force of the motor unit 34 is further reduced.

It should be noted that a voltage based on the vehicle speed detection signal is always applied to the control motor 84, and the biasing force of the spring 82 acts as a load to bring the motor into a locked state. , 12V control motor 8
Since the voltage of 4 is set to a maximum of 3 V, it functions without any trouble. In this case, the maximum voltage is set to 3V.
There is no problem at all up to about 6V.

As described above, in the power steering device 10 according to the first embodiment, the moving mechanism 50 (output torque control means) operates according to the running state of the vehicle, and the armature 36 of the brush 78 is moved. By changing the contact state with respect to (i.e., the number of effective conductors of the armature coil), the drive control of the motor unit 34 is performed in accordance with the vehicle running state. The power assist characteristics can be changed between the high-speed state and the vehicle, and the steering force can be favorably assisted. Further, since it has a simple structure that does not require a torque sensor or the like as in the related art, it is possible to greatly reduce costs and reduce the size and weight.

In the first embodiment, the moving mechanism 50 is operated according to the running state (vehicle speed) of the vehicle to change the contact state of the brush 78 with the armature 36. The steering angle (rack bar 2
(Rack stroke of No. 4).

That is, for example, in a straight traveling state (neutral state) of the vehicle, the brush 78 is located at a position where the number of effective conductors of the armature coil is minimized, and the brush 78 is gradually moved with steering. Is also good. According to this, in the straight traveling state of the vehicle, the driving force of the motor unit 34 is small, so that the power assisting force applied to the rack bar 24 is small, and the feeling of response increases. On the other hand, since the driving force of the motor unit 34 increases with the steering, the power assisting force applied to the rack bar 24 also increases, and the steering force of the input shaft 12 (steering wheel) is reduced.

Next, another embodiment of the present invention will be described. Note that components that are basically the same as those in the first embodiment are given the same reference numerals as in the first embodiment, and descriptions thereof are omitted. FIG. 6 is a cross-sectional view illustrating a schematic configuration of a moving mechanism unit 92 of a power steering device 90 according to the second embodiment.

The moving mechanism 92 of the power steering device 90 includes the power steering device 10 according to the first embodiment described above.
Similarly to the above, a brush 76 and a brush 78 are provided,
Both are fixed to the gear holder 54. Further, in the moving mechanism section 92, a pair of short brushes 94 and a short brush 96 are provided. These short brush 9
4. Of the short brushes 96, one short brush 94 is a fixed brush. The other short brush 96 is a moving brush, and
And the brush holder 98 is connected and fixed to the holding portion 60 of the moving gear 52. The short brush 94 and the short brush 96 are used to partially short-circuit the coil of the armature 36, and are electrically and mechanically connected by a coil spring (not shown). Therefore, the moving gear 52
Is rotated, the short brush 96 is moved, and the contact state with the armature 36 (the interval between the short brush 94 and the short brush 96, that is, the coil short-circuit portion of the armature 36) is changed to change the effective conductor of the coil of the armature 36. The number can be changed.

Further, in the moving mechanism 92,
The moving gear 52 is rotated by a control motor 84, and the control motor 84 is driven by the operation of a motor drive circuit 88 based on a vehicle speed detection signal.

Next, the operation of the second embodiment will be described. In the power steering device 90 (moving mechanism section 92), when the vehicle speed detection signal is input to the motor drive circuit 88, the control motor 84 operates according to the traveling speed of the vehicle. The operation of the control motor 84 causes the movement gear 5 to move.
2 is rotated, and one short brush 96 rotates together with the movement gear 52, and the interval between the short brush 94 and the short brush 96 is changed. Thereby, the effective length (the number of effective conductors) of the coil of the armature 36 is changed,
The driving force of the motor unit 34 increases and decreases. As a result, power assist according to the vehicle running state can be performed, and steering assist can be favorably assisted.

As described above, in the power steering device 90 according to the second embodiment, the moving mechanism 92 (output torque control means) operates according to the running state of the vehicle, and the armature of the short brush 96 By changing the state of contact with 36 (that is, the number of effective conductors of the armature coil), drive control according to the vehicle running state is performed. Thus, the power assist characteristic can be changed, and the steering force can be favorably assisted. Further, since it has a simple structure that does not require a torque sensor or the like as in the related art, it is possible to greatly reduce costs and reduce the size and weight.

In the second embodiment, the moving mechanism 92 may be operated (the short brush 96 may be moved) according to the steering angle (rack stroke of the rack bar 24).

FIG. 7 is a sectional view showing a schematic configuration of a moving mechanism 102 of a power steering apparatus 100 according to the third embodiment.

The moving mechanism 10 of the power steering device 100
2, a brush 76, a brush 78, a short brush 94, and a short brush 96 are provided similarly to the power steering device 90 according to the above-described second embodiment.
The brush 76, the brush 78, the short brush 94, and the short brush 96 are all fixed brushes.

Further, a slide resistor 104 as a variable resistor is provided between the short brush 94 and the short brush 96. This slide resistance 10
4 is located in the through hole 58 of the gear holder 54 and is electrically connected to the short brush 94 and the short brush 96, and the sliding portion 106 is connected and fixed to the holding portion 60 of the moving gear 52. ing. Therefore, the rotation of the moving gear 52 causes the sliding portion 10 of the slide resistance 104 to rotate.
6, the short brush 94 and the short brush 9
6 can be changed.

Further, also in the moving mechanism section 102, the moving gear 52 is rotated by the control motor 84, and the control motor 84 is driven by the operation of the motor drive circuit 88 based on the vehicle speed detection signal.

Note that the slide resistance 1
04 is set to be small.

Next, the operation of the third embodiment will be described. In the power steering device 100 (moving mechanism unit 102), when the vehicle speed detection signal is input to the motor drive circuit 88, the control motor 84 operates according to the traveling speed of the vehicle. By the operation of the control motor 84, the sliding portion 106 of the slide resistor 104 is moved, and the short brush 9
The electric resistance value between 4 and the short brush 96 is changed. Thereby, the magnetic flux generated by the armature coil between the short brush 94 and the short brush 96 is changed,
The driving force of the motor unit 34 increases and decreases. As a result, power assist according to the vehicle running state can be performed, and steering assist can be favorably assisted.

As described above, in the power steering apparatus 100 according to the third embodiment, the electric resistance value of the slide resistance 104 is output to the rack bar 24 by being changed according to the running state of the vehicle. The power assisting force (the driving force of the motor unit 34) increases or decreases in accordance with the running state of the vehicle, and performs a power assist based on the running state of the vehicle to output a predetermined output torque to the steering output shaft. The steering force can be favorably assisted. Further, since it has a simple structure that does not require a torque sensor or the like as in the related art, it is possible to greatly reduce costs and reduce the size and weight.

In the third embodiment as well, the moving mechanism 102 is operated (the sliding part 106 of the slide resistor 104 is moved) according to the steering angle (rack stroke of the rack bar 24). Is also good.

Next, FIG. 8 is a sectional view showing a configuration of a main part of a power steering apparatus 110 according to a fourth embodiment of the present invention.

In the power steering device 110, similarly to the power steering device 10 according to the above-described first to third embodiments, the motor unit 3 according to the left and right rotation directions of the input shaft 12 is provided.
And a magnetic pole for changing the position of the second magnetic pole 40 facing the first magnetic pole 38 in accordance with the magnitude of the input torque from the input shaft 12. Control means (holding plate 176, gear 21
2, lever 202, etc.).

Further, in the power steering device 110, an auxiliary magnet 112 is disposed on the inner peripheral surface of the housing 16.

The auxiliary magnet 112 is disposed on the inner peripheral surface of the housing 16 so as to face the second magnetic pole 40 whose position with respect to the first magnetic pole 38 is changed by the magnetic pole control means. (Input shaft 1
2) The polarity of the second magnetic pole piece 40 is different from the polarity of the second magnetic pole piece 40 in the neutral state (N pole-S pole state or S pole-N
Polar state).

Power steering device 11 according to the fourth embodiment
0, the driving force of the motor unit 34 is applied to the rack bar 24 as an auxiliary driving force by the operation of the energization switching mechanism and the magnetic pole control means, and power assist based on the input torque from the input shaft 12 is performed, as described above. The steering force of the input shaft 12 (steering wheel) can be reduced.

Further, in this power steering device 110, an auxiliary magnet 112 having a polarity different from the polarity of the second magnetic pole 40 in the neutral state of the steering wheel (input shaft 12) is applied to the second magnetic pole 40. They are provided facing each other.

For this reason, even if the first magnetic pole 38 and the second magnetic pole 40 face each other in the neutral position at the neutral position of the steering wheel (input shaft 12), the second magnetic pole 4
0 attracts each other to the auxiliary magnet 112, and as a result, can be stably returned to the neutral position. Therefore, a good steering feeling (neutral feeling) is obtained when the steering wheel (input shaft 12) returns to the neutral position.

As described above, in the power steering device 110 according to the fourth embodiment, the steering wheel (input shaft 1)
In addition to performing power assist based on the input torque from 2) and outputting a predetermined output torque to the rack bar 24 (steering output shaft), optimal power assist can be performed, and the steering wheel after power assist Good steering feel when returning to neutral position (neutral feeling)
And this can be realized with a simple structure.

Next, FIG. 9 is a schematic sectional view showing the overall configuration of a power steering apparatus 120 according to a fifth embodiment of the present invention, and FIG. Device 120
Is shown in a sectional view along line 10-10 in FIG.

In the power steering device 120, similarly to the power steering device 110 according to the above-described fourth embodiment, the brushes 76 and 78 of the motor unit 34 are moved in accordance with the left and right rotation directions of the input shaft 12. A power switching mechanism for switching the power supply direction of the motor;
Magnetic pole control means (holding plate 176, gear 212, lever 202, etc.) for changing the position of the second magnetic pole 40 facing the magnetic pole 38 of FIG.

Further, the second magnet pole 40 is partially provided with an auxiliary magnet section 122.

The auxiliary magnet section 122 is partially provided on the periphery of the second magnetic pole 40 whose position facing the first magnetic pole 38 is changed by the magnetic pole control means, and is provided with a steering wheel (input shaft 12). In the neutral state, the polarity is set to be different from the polarity of the opposing first magnetic pole piece 38 (to be an N-pole-S-pole state or an S-pole-N-pole state).

Power steering device 12 according to the fifth embodiment
0, the driving force of the motor unit 34 is applied to the rack bar 24 as an auxiliary driving force by the operation of the energization switching mechanism and the magnetic pole control means, and power assist based on the input torque from the input shaft 12 is performed, as described above. The steering force of the input shaft 12 (steering wheel) can be reduced.

Further, in the power steering device 120, the second magnetic pole element 40 has a polarity different from the polarity of the first magnetic pole element 38 facing in the neutral state of the steering wheel (input shaft 12). Is partially provided with an auxiliary magnet section 122.

For this reason, even if the first magnetic pole 38 and the second magnetic pole 40 face each other in the neutral position at the neutral position of the steering wheel (input shaft 12), the second magnetic pole 4
The zero auxiliary magnet part 122 attracts the first magnetic pole piece 38, and as a result, the second magnetic pole piece 40 can stably return to the neutral position. Therefore, a good steering feeling (neutral feeling) is obtained when the steering wheel (input shaft 12) returns to the neutral position.

As described above, in the power steering apparatus 120 according to the fifth embodiment, the steering wheel (input shaft 1)
In addition to performing power assist based on the input torque from 2) and outputting a predetermined output torque to the rack bar 24 (steering output shaft), optimal power assist can be performed, and the steering wheel after power assist Good steering feel when returning to neutral position (neutral feeling)
And this can be realized with a simple structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the entire configuration of a power steering device according to a first embodiment of the present invention, as viewed from the front.

FIG. 2 is a cross-sectional view showing the entire configuration of the power steering device according to the first embodiment of the present invention, as viewed from the rear side.

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

FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 3, showing a configuration of a moving mechanism of the power steering apparatus according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a motor drive circuit of the power steering device according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view corresponding to FIG. 4 and showing a configuration of a moving mechanism of a power steering device according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view corresponding to FIG. 4 and illustrating a configuration of a moving mechanism of a power steering device according to a third embodiment of the present invention.

FIG. 8 is a cross-sectional view corresponding to FIG. 3 and illustrating a configuration of a motor unit of a power steering device according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view, viewed from the front, showing the entire configuration of a power steering device according to a fifth embodiment of the present invention.

FIG. 10 is a sectional view taken along line 10-10 in FIG. 9 showing a configuration of a motor unit of a power steering apparatus according to a fifth 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 section 36 armature 38 First magnetic pole 40 Second magnetic pole 42 Motor rotation axis 50 Moving mechanism (output torque control means) 52 Moving gear 60 Holder 76 brush (power supply brush) 78 brush (power supply brush) 84 Control motor 88 Motor drive circuit 90 Power steering device 92 Moving mechanism (output torque control means) 94 short brush 96 short brush 100 Power steering device 102 Moving mechanism (output torque control means) 104 Slide resistance (variable resistor) 110 Power steering device 112 Auxiliary magnet 120 Power steering device 122 Auxiliary magnet part 176 holding plate (magnetic pole control means) 202 lever (magnetic pole control means) 212 gear (magnetic pole control means) 214 Limit switch (Electrification switching mechanism)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Hasegawa 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Shuji Fujita 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation ( 56) References JP-A-9-224361 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 23/00 B62D 5/04

Claims (5)

(57) [Claims] 1. A motor comprising an armature and first and second magnetic poles provided on opposite sides of the armature based on an input torque from a steering input shaft connected to steering means. In a power steering device that performs power assist and outputs a predetermined output torque to a steering output shaft for turning a steered wheel, a power supply brush of the motor is supplied to a power supply brush of the motor in accordance with a left-right rotation direction of the steering input shaft. An energization switching mechanism for switching an energization direction, and changing a facing position of the first magnetic pole and the second magnetic pole relatively around an axis in accordance with a magnitude of an input torque from the steering input shaft; Magnetic pole control means for controlling the power assisting force of the motor;
Between the short brush to be entangled and the short brush
And a variable resistor electrically connected to the vehicle.
A power steering apparatus comprising: an output torque control unit that changes an electric resistance value of the variable resistor according to a state and controls a power assisting force of the motor. 2. An output torque control means, comprising:
A transfer gear connected to the antibody and rotatably supported
Gear and the driving gear connected to the
A control motor for rotating the gear for movement.
The power steering device according to claim 1, wherein: 3. A vehicle speed signal is generated based on a running speed of the vehicle.
Vehicle speed signal generating means, and the output torque control means
The power assist force of the motor based on the vehicle speed signal
Controlling, that the power steering apparatus according to claim 1 or claim 2, characterized in. 4. An armature and opposite sides of said armature are provided.
The first and second magnetic poles
Input torque from the steering input shaft connected to the steering means
Power output based on the specified output torque
Output to the steering output shaft for steering the steered wheels
In the steering device, the motor may be driven in accordance with the left and right rotation directions of the steering input shaft.
An energization switching mechanism that switches an energization direction to the power supply brush, and the energization switching mechanism according to the magnitude of input torque from the steering input shaft.
The opposing position of the first magnetic pole and the second magnetic pole is set around the axis.
Control relative to the power assist power of the motor
Magnetic pole control means for performing the magnetic pole control of the first magnetic pole and the second magnetic pole
Either magnetic pole whose facing position is changed by means
In the neutral position of the steering means,
And the polarity is different, and is provided to face the one magnetic pole.
And an auxiliary magnet, the power steering apparatus characterized by comprising a. 5. An armature and opposite sides of said armature are provided.
The first and second magnetic poles
Input torque from the steering input shaft connected to the steering means
Power output based on the specified output torque
Output to the steering output shaft for steering the steered wheels
In the steering device, the motor may be driven in accordance with the left and right rotation directions of the steering input shaft.
Energizing the switching mechanism for switching the energizing direction of the power supply brush, the according to the magnitude of the input torque from the steering input shaft
The opposing position of the first magnetic pole and the second magnetic pole is set around the axis.
Control relative to the power assist power of the motor
Magnetic pole control means, and one of the first magnetic pole and the second magnetic pole
Partially provided on the magnetic pole and located in the neutral position of the steering means
Magnet with polarity different from that of the other magnetic pole
Power steering apparatus characterized by comprising: a part, the.