JPH10244949A - Power steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power steering device which can output a prescribed output torque in response to the input torque from a steering input shaft to a steering output shaft and carry out the most suitable power assist. SOLUTION: In an electrification control part 214 provided in a power steering device, operation contact points 216A, 216B are provided on a lever 215 and can be contacted and push-pressed to variable resistance plates 217, 219 arranged facingly. The lever 215 is swung in response to the input torque from a steering input shaft. The variable resistance plates 217, 219 are so-called carbon pile and their electric resistance values are changed in response to the push-press force. Therefore, the electric resistance value of the electricity supply circuit to a motor part is changed and the drive force of the motor is changed in response to the input torque from the steering input shaft and the most suitable power assist can be carried out by outputting a prescribed output torque in response to the input torque to the steering output shaft.

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, a means for changing a power supply frequency and a power supply voltage is used to control an output generated by the motor. Circuits are indispensable and costly. Therefore, a so-called actual air gap type electric motor capable of solving such a defect 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 flows, and a rotor is arranged 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 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 facing positions of the first and second stators. Is changed (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 power steering device (power steering) for a vehicle, it is desirable to change a power assist force in accordance with an input torque from the steering. In this regard, the electric motor disclosed in the above publication has a configuration in which the output torque of the rotor (rotary shaft) is adjusted by manually moving the first or second stator, so that the electric motor using the electric motor as it is is used. In the power steering device, the power assist force cannot be changed according to the input torque from the steering input shaft, that is, the power assist according to the input torque is performed to output a predetermined output torque to the steering output shaft. There was a drawback that can not be.

[0005]

SUMMARY OF THE INVENTION In consideration of the above facts, the present invention provides a power source capable of outputting a predetermined output torque corresponding to an input torque from a steering input shaft to a steering output shaft to perform optimal power assist. The aim is to obtain a steering device.

[0006]

According to a first aspect of the present invention, there is provided a power steering apparatus comprising a motor having an armature and first and second magnetic poles provided on both sides of the armature. A power steering device that performs a power assist based on an input torque from a steering input shaft connected to a steering wheel to output a predetermined output torque to a steering output shaft for steering a steered wheel; An energization switching mechanism that switches the energization direction to the power supply brush of the motor according to the left and right rotation directions of the input shaft, and changes an electric resistance value of an energization circuit to the power supply brush according to the input torque of the steering input shaft. Output torque control means for controlling the power assisting force of the motor.

In the power steering apparatus according to the first aspect, the motor is connected to a steering input shaft to which 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 input shaft (steering wheel)
Steering force is reduced. Further, when the steering input shaft is switched between left and right, the direction of energization to the motor is switched by the conduction switching mechanism, and the rotation direction of the steering output shaft is switched, so that it is possible to respond to the steering direction of the steering input shaft.

Further, in this power steering device, the output torque control means operates in accordance with the input torque from the steering input shaft, and the electric resistance value of the current supply circuit to the power supply brush of the motor is changed. As a result, the amount of current (current value) to the armature is changed, and the driving force of the motor increases or decreases. In this case, the operation of the output torque control means (that is, the increase or decrease of the electric resistance value of the power supply circuit to the power supply brush) corresponds to the magnitude of the input torque from the steering input shaft, and the amount of power supply to the armature ( The current value is changed according to the magnitude of the input torque. That is, by changing the electric resistance value of the power supply circuit to the power supply brush, the power assist force (motor driving force) output to the steering output shaft increases or decreases in accordance with the input torque from the steering input shaft. That is, similarly to the conventional hydraulic power steering device, it is possible to perform a power assist based on the input torque from the steering input shaft and output a predetermined output torque to the steering output shaft. Furthermore, the power steering device has a simple structure that does not require a torque sensor, a motor controller, and the like as in the related art, and can greatly reduce the cost and reduce the size and weight.

Thus, in the power steering apparatus according to the first aspect, the output torque control means operates in accordance with the input torque from the steering input shaft, and the electric resistance value of the current supply circuit to the power supply brush is changed. Thus, the drive control of the motor according to the input torque from the steering input shaft is performed, and the steering force can be favorably assisted. Further, the structure is simple, and the cost and the size and weight can be significantly reduced.

[0010]

1 to 3 schematically show a power steering apparatus 10 according to a first embodiment of the present invention in a 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 disposed in a direction substantially perpendicular to the rack bar 24 as a steering output shaft, is supported by a housing 194 by a bearing 192, and has a steering wheel (not shown) attached thereto. The bearing 192 that supports 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. The input shaft 12 has a pinion 19
6 is provided, and the rack gear 19 of the rack bar 24 is provided.
8 is engaged. Also, at the tip of the input shaft 12,
Corresponding to this, a holding cylinder 200 that can move to the left and right is provided, and one end of a lever 202 as a connecting member is connected to the holding cylinder 200. For this reason,
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 a motor unit 3
4 is provided. The motor unit 34 is a so-called print motor, and includes an armature 36 and first and second magnetic poles 38 and 40 provided on both sides of the armature 36.
It is composed of 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. Armature 36
A gear 204 is provided on the motor rotation shaft 42 of
Further, it is 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 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 the holding plate 176 is
It is supported by. 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. The holding plate 176 is provided with a gear 212, and the gear 212 is further provided with the lever 20 described above.
2 is engaged with a rack portion 203 formed at the other end. Therefore, the second magnetic pole element 40 is configured to be rotationally moved by moving the lever 202 along the longitudinal direction.

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 and the like of the lever 202 are set.

The motor section 34 is integrally provided with an energization control section 214 as an energization switching mechanism and output torque control means.

As shown in detail in FIG.
In the embodiment, the lever 215 is supported by the support shaft 218 so as to be swingable right and left, and the lever 215 is connected to the lever 202 described above. For this reason, the lever 20
2 is moved along the longitudinal direction, whereby the lever 2 is moved.
15 swings right and left around the support shaft 218.
The lever 215 has a pair of operating contacts 216A,
16B is attached.

Further, on both sides of the lever 215, variable resistance plates 217 and 219 are disposed so as to face the operating contacts 216A and 216B, respectively. These variable resistance plates 217 and 219 are fixedly contacted with a so-called carbon pile, and the electric resistance value changes according to the load (stress).

The energization control section 214 has a pair of operating contacts 216A and 216B connected to the brushes 76 and 78 of the motor section 34.
19 is connected to a power supply. Thereby, the lever 20
When the operating contacts 216A and 216B connected to the input shaft 2 move left and right to come into contact with the variable resistance plates 217 and 219, the steering state of the input shaft 12 (the left / right switching state) is detected. The direction of energization to the motor unit 34 (armature 36) can be switched according to the steering direction. Further, at this time, a pair of operating contacts 216A,
216B presses the variable resistance plates 217 and 219 according to the steering force of the input shaft 12, respectively, and the electric resistance value of the variable resistance plates (carbon piles) 217 and 219 is changed.

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 traveling straight), the operating contacts 216A and 216B of the energization control unit 214 do not move, and the energization control unit 214 Is in the OFF state, and 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. 2, 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 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 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.
As a result, 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 contacts 216A and 216B of the power supply control unit 214 move with the movement of the lever 202, and the variable resistance plate 217 or the variable resistance plate 2
Touch 19. As a result, the power supply control unit 214 is turned ON.
As a result, power is supplied to the motor section 34 (armature 36), and the armature 36 of the motor section 34 rotates.

As a result, 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.

On the other hand, when the input shaft 12 is steered to the left (in the direction of arrow C in FIG. 2), 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 arrow B) to steer the steered wheels.

Also in this case, immediately after the input shaft 12 is steered, 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 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 in 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, with the movement of the lever 202, the operating contacts 216A and 216B of the energization control unit 214 move in the opposite direction to the above, and come into contact with the variable resistance plate 219 or the variable resistance plate 217, respectively. Thereby, the energization control unit 21
4 is turned on, and the motor section 34 (armature 36) is energized, and the armature 36 of the motor section 34 rotates in the opposite direction to that described above.

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.

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 in accordance with the input torque, and performs power assist based on the input torque from the input shaft 12 to perform the predetermined power assisting, similarly to the conventional hydraulic power steering device. An output torque can be applied to the rack bar 24.

The steering wheel (input shaft 1)
When 2) is switched between left and right, the motor unit 3 is operated by the operation of the lever 202 and the energization control unit 214 as described above.
4 is switched, and the rotation direction of the motor rotation shaft 42 is switched to correspond to the steering direction of the input shaft 12.

Further, in the power steering device 10, the lever (the lever 20) is changed according to the magnitude of the input torque from the input shaft 12.
2) with the operation contact 216 of the energization control unit 214.
A and 216B press the variable resistance plate 217 or the variable resistance plate 219, respectively. Thereby, the electric resistance values of the variable resistance plates (carbon piles) 217 and 219 are changed,
The amount of current (current value) to the motor unit 34 (armature 36) is changed, and the driving force of the motor unit 34 increases or decreases. in this case,
The change in the electric resistance value of the variable resistance plates (carbon piles) 217 and 219 (that is, the increase or decrease in the electric resistance value of the current supply circuit to the armature 36) corresponds to the magnitude of the input torque from the input shaft 12. The amount of current (current value) to the armature 36 is changed in accordance with the magnitude of the input torque. That is,
By changing the electric resistance value of the current supply circuit to the armature 36, the power assist force (the driving force of the motor unit 34) output to the rack bar 24 increases or decreases in accordance with the input torque from the input shaft 12. As a result, similarly to the conventional hydraulic power steering device, a predetermined output torque can be output to the rack bar 24 by performing power assist based on the input torque from the input shaft 12.

As described above, in the power steering apparatus 10 according to the first embodiment, the energization control section 214 (output torque control means) operates in accordance with the input torque from the input shaft 12 to change the variable resistance. The electric resistance of the plates (carbon piles) 217 and 219 (the electric resistance of the current supply circuit to the armature 36) is changed, so that the motor unit 34 according to the input torque is changed.
, And the steering force can be favorably assisted. Further, the structure is simple, and the cost and the size and weight can be significantly reduced. In addition, since it has a simple structure that does not require a torque sensor, a motor controller, and the like as in the related art, it is possible to significantly reduce costs and reduce size and weight.

Further, in the power steering device 10, the input shaft 1
The motor unit 34 is directly connected to the rack bar 24 independently of the second, and the swing of the input shaft 12 is transmitted by the lever 202, and the second magnetic pole 40 is rotated around the axis.
As described above, since the motor unit 34 can be disposed separately and independently from the input shaft 12, the mountability on the vehicle is improved. For this reason, it is possible to easily increase the size of the motor section 34 to increase the output. Further, the motor unit 34
Energization control unit 2 for switching the energization direction to (armature 36)
Since the motor 14 is provided integrally with the motor unit 34 and the energization control unit 214 is operated by the movement of the lever 202, the structure of the apparatus can be simplified.

In the first embodiment, the lever 2 is supported by the support shaft 218 so as to be able to swing right and left.
Although the lever 15 is directly connected to the lever 202 and the lever 215 swings right and left around the support shaft 218 by the movement of the lever 202, the mechanism for connecting the lever 215 and the lever 202 is not limited to this.

For example, as shown in FIG. 5, a structure in which a belt 221 is wound around a support shaft 220 fixed to a lever 215 and both ends of the belt 221 are fixed to the lever 202 (in other words, via the belt 221). The lever 215 may be connected to the lever 202). Even in this case, the energization control unit 214 can be operated according to the input torque from the input shaft 12.

Next, a second 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 shows the motor section 3 of the power steering device 10.
4 shows an energization switching mechanism and an energization control unit 222 as output torque control means according to the second embodiment applied to FIG.

In the power supply control unit 222, a lever 215 is supported by a support shaft 218 so as to be able to swing left and right, and the lever 215 is connected to the lever 202 described above. Therefore, the lever 215 is configured to swing right and left around the support shaft 218 by moving the lever 202 along the longitudinal direction. The lever 215 is provided with a pair of operating contacts 216A and 216B.

Further, on both sides of the lever 215, the fixed contacts 2 are opposed to the operating contacts 216A and 216B, respectively.
23A and 223B are arranged. Also, lever 21
A variable resistor (Slidac) 224 is connected to the tip of the fifth element 5.

As shown in FIG. 7, the energization control unit 222 includes a pair of operating contacts 216A and 216B connected to the motor unit 34.
The fixed contacts 223A and 223B are connected to a power supply via a variable resistor (Slidac) 224. Thereby, the operating contacts 216A, 21 connected to the lever 202
6B are moved to the left and right, respectively, and the fixed contacts 223A, 223 are moved.
By touching 3B, the steering state (switching state between left and right) of input shaft 12 is detected, and the energizing direction to motor unit 34 (armature 36) can be switched in accordance with the steering direction of input shaft 12. it can. At this time, the lever 21
Reference numeral 5 denotes a configuration in which a variable resistor (Slidac) 224 is operated to change an electric resistance value of a current supply circuit to the armature 36.

The power supply control unit 22 according to the second embodiment
In the power steering device 10 to which the power steering control unit 2 is applied, when the steering wheel (the input shaft 12) is not steered (the vehicle is in a straight running state), the operating contacts 216A and 216B of the power supply control unit 222 do not move, and the power supply control is performed. The section 222 is in the OFF state, and 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, the operating contacts 216A and 216B of the energization control unit 222 move with the movement of the lever 202, and move to the fixed contact 223A or the fixed contact 223B, respectively. Contact. As a result, the energization control unit 222 is turned on to energize the motor unit 34 (armature 36), and the armature 36 of the motor unit 34 rotates. As a result, the driving force of the motor unit 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 steering force of the input shaft 12 (steering wheel) is reduced.

On the other hand, when the input shaft 12 is switched between left and right, the operating contacts 216A and 216B of the power supply controller 222 move in the opposite direction to the above, and come into contact with the fixed contact 223A or 223B, respectively. As a result, the power supply control unit 222 is turned on, and power is supplied to the motor unit 34 (armature 36), so that the armature 36 of the motor unit 34 rotates in the opposite direction to that described above. As a result, the driving force of the motor unit 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 steering force of the input shaft 12 (steering wheel) is reduced.

As described above, when the steering wheel (input shaft 12) 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 energizing control unit 222, and the motor rotating shaft 42 is switched. Can be changed to correspond to the steering direction of the input shaft 12.

Further, in the energization control unit 222,
The lever 215 activates the variable resistor (slidac) 224 according to the magnitude of the input torque from the input shaft 12 (with the movement of the lever 202). As a result, the electric resistance value of the current supply circuit to the motor section 34 (the armature 36) is changed, the amount of current (current value) to the armature 36 is changed, and the driving force of the motor section 34 is increased or decreased. In this case, a change in the electric resistance value of the variable resistor (Slidac) 224 (that is, an increase or a decrease in the electric resistance value of the current supply circuit to the armature 36)
It corresponds to the magnitude of the input torque from the input shaft 12,
The amount of current (current value) to the armature 36 is changed according to the magnitude of the input torque. That is, by changing the electric resistance value of the energizing circuit to the armature 36, the power assist force (the driving force of the motor unit 34) output to the rack bar 24 corresponds to the input torque from the input shaft 12. The power assist is performed based on the input torque from the input shaft 12 and a predetermined output torque can be output to the rack bar 24, similarly to the conventional hydraulic power steering device.

As described above, the power supply control unit 222 (the power steering apparatus 10 to which the power control unit 10 is applied) according to the second embodiment.
Then, the variable resistor 224 (output torque control means) operates according to the input torque from the input shaft 12 to
By changing the electric resistance value of the power supply circuit to the motor, the drive control of the motor unit 34 is performed according to the input torque, and the steering force can be favorably assisted. further,
Since the structure is simple, it is possible to significantly reduce the cost and reduce the size and weight. In addition, it has a simple structure that does not require a torque sensor or a motor controller as in the past,
Significant reduction in cost and reduction in size and weight can be achieved.

In the second embodiment, the lever 2 is supported by the support shaft 218 so as to be able to swing right and left.
Although the lever 15 is directly connected to the lever 202 and the lever 215 swings right and left around the support shaft 218 by the movement of the lever 202, the mechanism for connecting the lever 215 and the lever 202 is not limited to this.

For example, as shown in FIG. 8, a belt 228 is wound around a support shaft 226 fixed to a lever 215, and both ends of the belt 228 are fixed to the lever 202 (in other words, via the belt 228) The lever 215 may be connected to the lever 202). Even in this case, the energization control unit 222 can be operated according to the input torque from the input shaft 12.

[0049]

As described above, the power steering apparatus according to the present invention can output a predetermined output torque corresponding to the input torque from the steering input shaft to the steering output shaft to perform optimal power assist. It has an excellent effect.

[Brief description of the drawings]

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

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. 2 showing a configuration of a motor unit of the power steering apparatus according to the first embodiment of the present invention.

FIG. 4 is a front view showing a configuration of an energization control unit of the power steering device according to the first embodiment of the present invention.

FIG. 5 is a front view showing another example of the energization control unit of the power steering device according to the first embodiment of the present invention.

FIG. 6 is a front view illustrating a configuration of an energization control unit of a power steering device according to a second embodiment of the present invention.

FIG. 7 is a circuit diagram of an energization control unit shown in FIG. 6;

FIG. 8 is a front view showing another example of the power supply control unit of the power steering device according to the second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 10 power steering device 12 input shaft (steering input shaft) 24 rack bar (steering output shaft) 34 motor unit 36 armature 38 first magnetic pole 40 second magnetic pole 42 motor rotation shaft 76 brush (power supply brush) 78 Brush (power supply brush) 202 lever 214 energization control unit (energization switching mechanism, output torque control means) 215 lever 216A operating contact 216B operating contact 217 variable resistance plate 219 variable resistance plate 222 energization control unit (energization switching mechanism, output torque control means) ) 223A fixed contact 223B fixed contact 224 Variable resistor

 ──────────────────────────────────────────────────の 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

Claims (1)

[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 a steering wheel. 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 the energization direction, and output torque control means for changing an electric resistance value of an energization circuit to the power supply brush according to an input torque of the steering input shaft, and controlling a power assist force of the motor. A power steering device comprising: