JP3732154B2 - Power steering device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power steering apparatus provided with a flow rate control valve for controlling a flow rate guided to a power cylinder side.
[0002]
[Prior art]
The flow control valve incorporated in this type of power steering system incorporates a spool in the main body, one end of this spool faces one pilot chamber that is always in communication with the pump port, and the other end of the spool is interposed with a spring. It faces the other pilot room. A fixed orifice is provided on the downstream side of the one pilot chamber, and pressure oil is guided to a steering valve that controls the power cylinder through the fixed orifice.
[0003]
On the other hand, the pressure on the upstream side of the orifice is set as the pilot pressure of the one pilot chamber, the pressure on the downstream side is set as the pilot pressure of the other pilot chamber, and the moving position of the spool is controlled by the pressure balance of both pilot chambers. I have to.
Depending on the movement position of the spool, the pump discharge amount is divided into a control flow rate QP that leads to the steering valve side and a return flow rate QT that is circulated to the tank or the pump.
The spool maintains a constant differential pressure before and after the fixed orifice so that a constant control flow rate QP is always supplied to the steering valve side that controls the power cylinder.
[0004]
[Problems to be solved by the invention]
In the conventional apparatus as described above, a constant control flow rate QP is always supplied from the flow control valve to the steering valve side that controls the power cylinder. In other words, a constant control flow rate QP is always supplied to the steering valve regardless of the vehicle speed and the steering situation.
However, if the control flow rate QP is specified regardless of the vehicle speed and the steering situation, for example, when QP> QM with respect to the flow rate QM required by the power cylinder, the excess flow rate is passed through the steering valve. It must be returned to the tank.
[0005]
Returning the excessive flow rate to the tank through the steering valve in this way increases the pressure loss of the circuit accordingly. In other words, the pump must continue to consume the driving torque for this pressure loss. Therefore, as the driving torque of the pump increases, a larger amount of energy is consumed. In addition, since the control flow rate QP is set in accordance with the maximum required flow rate of the power cylinder, in most cases, some surplus flow rate is recirculated to the tank. Therefore, this conventional apparatus has a problem that the energy loss becomes large.
An object of the present invention is to provide a power steering device in which energy loss is minimized by controlling a control flow rate QP in accordance with a traveling condition and a steering situation of a vehicle.
[0006]
[Means for Solving the Problems]
  ThisThe present invention controls a steering valve for controlling a power cylinder, a variable orifice provided upstream of the steering valve, a solenoid for controlling the opening of the variable orifice, and a solenoid current command value I for driving the solenoid. Controller, steering angle sensor, steering torque sensor connected to the controller,Steering angular velocity sensor,And a vehicle speed sensor, and a flow rate control valve that distributes the flow rate supplied from the pump to a control flow rate that leads to the steering valve and a return flow rate that returns to the tank in accordance with the opening of the variable orifice, A solenoid current command value Iθ corresponding to the steering angle from the angle sensor, and a solenoid current command value It corresponding to the steering torqueThe solenoid current command value Iω corresponding to the steering angular velocity from the steering angular velocity sensor andIs calculated or stored, and the solenoid current command value Iθ for the steering angle system and the solenoid current command value It for the steering torque system are respectively multiplied by solenoid current command values IV1 and IV2 set based on the vehicle speed.Further, the solenoid current command value Iω for the steering angular velocity system has a limit value that is a solenoid current command value IV3 set based on the vehicle speed, and the calculated solenoid current command value Id for the steering angular velocity system after the calculation,Comparison was made by comparing the magnitude of the solenoid current command value for the steering angle system and the solenoid current command value for the steering torque system.mostbigValueIs a solenoid current command value I.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS.
The main body B incorporates the spool 1 of the flow control valve V.
The spool 1 has one end facing one pilot chamber 2 and the other end facing the other pilot chamber 3.
The one pilot chamber 2 is always in communication with the pump P through the pump port 4. The one pilot chamber 2 communicates with the inflow side of the steering valve 9 that controls the power cylinder 8 via the flow path 6 → the variable orifice a → the flow path 7.
[0010]
On the other hand, in the other pilot chamber 3, a spring 5 is interposed and communicated with the inflow side of the steering valve 9 through a flow path 10 and a flow path 7. Therefore, the pilot chambers 2 and 3 communicate with each other through the variable orifice a → the flow path 7 → the flow path 10, and the pressure on the upstream side of the variable orifice a acts on one of the pilot chambers 2 and downstream. The pressure on the side acts on the other pilot chamber 3. The opening of the variable orifice a is controlled by a solenoid current command value I for the solenoid SOL.
[0011]
The spool 1 maintains a position where the acting force of one pilot chamber 2 and the acting force of the other pilot chamber 3 and the spring force of the spring 5 are balanced, but at the balanced position, the opening of the tank port 11 is maintained. The degree is decided.
For example, when the pump drive source 12 such as an engine is stopped, no pressure is generated in the pilot chambers 2 and 3 because no pressure is supplied to the pump port 4. Therefore, in this case, the spool 1 maintains the illustrated normal position by the action of the spring 5.
[0012]
When the pump drive source 12 is operated from the above state to drive the pump P, pressure oil is supplied to the pump port 4 and a flow is generated in the variable orifice a. When a flow occurs in the variable orifice a in this way, a differential pressure is generated before and after that, and a pressure difference is generated in both pilot chambers 2 and 3 by this differential pressure. And according to this pressure difference, the spool 1 moves against the spring 5 from the position shown in the figure, and maintains the above-described balance position.
[0013]
When the spool 1 moves against the spring 5 in this way, the opening degree of the tank port 11 is increased, but the pump 4 is led to the steering valve 9 side according to the opening degree of the tank port 11 at this time. A distribution ratio between the control flow rate QP and the return flow rate QT circulated to the tank T or the pump P is determined. In other words, the control flow rate QP is determined according to the opening degree of the tank port 11.
[0014]
The fact that the control flow rate QP is controlled according to the opening degree of the tank port 11 determined by the moving position of the spool 1 as described above will ultimately determine the control flow rate QP according to the opening degree of the variable orifice a. . This is because the movement position of the spool 1 is determined by the pressure difference between the pilot chambers 2 and 3, and the opening of the variable orifice a determines this pressure difference.
[0015]
Therefore, in order to control the control flow rate QP according to the vehicle speed and the steering situation, it is only necessary to control the opening of the variable orifice a, that is, the solenoid current command value I for the solenoid SOL. Because the opening of the variable orifice a is controlled in proportion to the excitation current of the solenoid SOL, the opening is kept to a minimum in the non-excitation state, and the opening is increased as the excitation current is increased. Because.
[0016]
On the other hand, the steering valve 9 to which the control flow rate QP is guided controls the supply amount to the power cylinder 8 in accordance with an input torque (steering torque) of a steering wheel (not shown). For example, if the steering torque is large, the steering valve 9 is largely switched to increase the supply amount to the power cylinder 8, and conversely if the steering torque is small, the switching amount of the steering valve 9 is decreased and the power to the power cylinder 8 is reduced. The supply amount is reduced. The power cylinder 8 exhibits a larger assist force as the amount of pressure oil supplied increases, and the assist force decreases as the amount of supply decreases.
Note that the amount of switching between the steering torque and the steering valve 9 is set by a torsional reaction force such as a torsion bar (not shown).
[0017]
The flow rate QM supplied to the power cylinder 8 as described above is controlled by the steering valve 9, but the control flow rate QP supplied to the steering valve 9 is controlled by the flow rate control valve V as described above. ing. Here, if the required flow rate QM required by the power cylinder 8 and the control flow rate QP determined by the flow rate control valve V are made as equal as possible, the energy loss on the pump P side can be kept low. This is because the energy loss on the pump P side is caused by the difference between the control flow rate QP and the required flow rate QM of the power cylinder 8.
[0018]
Therefore, in the first embodiment, the opening degree of the variable orifice a is controlled so that the control flow rate QP is as close as possible to the required flow rate QM of the power cylinder 8. The opening of the variable orifice a is determined by the solenoid current command value I for the solenoid SOL as described above. The controller C described below controls the solenoid current command value I.
[0019]
A steering angle sensor 16, a steering torque sensor 17, and a vehicle speed sensor 18 are connected to the controller C. The solenoid current command value I for the solenoid SOL is controlled based on the output signals of these sensors 16-18.
Reference numeral 19 in FIG. 1 denotes a drive mechanism connected between the controller C and the solenoid SOL, and current is supplied to the solenoid SOL via this drive mechanism.
[0020]
FIG. 2 shows a control system of the controller C.
As described above, the steering angle signal from the steering angle sensor 16, the steering torque signal from the steering torque sensor 17, and the vehicle speed signal from the vehicle speed sensor 18 are input to the controller C.
When the steering angle signal is input, the controller C specifies the solenoid current command value Iθ based on the steering angle at that time. This solenoid current command value Iθ is determined on the basis of a theoretical value at which the relationship between the steering angle and the control flow rate QP is linear. However, the solenoid current command value Iθ is set to zero if the steering angle is equal to or less than the set value. That is, when the steering wheel is neutral or in the vicinity thereof, the solenoid current command value Iθ is set to zero.
[0021]
Further, the solenoid current command value Iθ for the steering angle may be stored in the controller C in advance as a table value, or may be calculated by the controller C each time based on the steering angle.
[0022]
When the solenoid current command value Iθ is obtained based on the steering angle as described above, this value is multiplied by the solenoid current command value IV1 based on the vehicle speed signal.
The solenoid current command value IV1 based on this vehicle speed signal outputs 1 when the vehicle speed is in a low speed range, and outputs a decimal value less than 1 in the high speed range. Then, in an intermediate region between the low speed region and the high speed region, a value inversely proportional to the vehicle speed is output. Therefore, the solenoid current command value Iθ is output as it is in the low speed range, but the output value decreases as the speed increases. In other words, the responsiveness is kept high in the low speed range, but the responsiveness is lowered in the high speed range. This is because, in general, high responsiveness is not required during high-speed traveling, and high responsiveness is generally required in the low speed range.
[0023]
On the other hand, when the steering torque is input, the controller C specifies the solenoid current command value It based on the magnitude of the steering torque at that time. This solenoid current command value It is also determined based on a theoretical value that makes the relationship between the steering torque and the control flow rate QP linear. The solenoid current command value It is also set to zero if the steering torque is equal to or less than the set value. That is, when the steering wheel is not steered, the solenoid current command value It is set to zero.
[0024]
Further, the solenoid current command value It for the steering torque may be stored in advance in the controller C as a table value, or may be calculated by the controller C each time based on the steering torque.
In any case, when the solenoid current command value It is obtained based on the steering torque, this value is multiplied by the solenoid current command value IV2 based on the vehicle speed signal.
The solenoid current command value IV2 based on this vehicle speed signal also outputs 1 when the vehicle speed is in the low speed range and outputs a decimal value less than 1 in the high speed range. Further, in the intermediate range between the low speed range and the high speed range, the output value is made to be inversely proportional to the vehicle speed. For this reason, the solenoid current command value It is output as it is in the low speed range, but the output value decreases as the speed increases. That is, the responsiveness is kept high in the low speed range, and the responsiveness is lowered in the high speed range.
[0025]
When the solenoid current command value (Iθ × IV1) for the steering angle system and the solenoid current command value (It × IV2) for the steering torque system are specified as described above, these two values are compared, and the larger one is compared. Select a value. The reason for selecting the larger value will be described in detail in the description of the action.
When the larger value is selected, the standby solenoid current command value Is is added to the selected value (Iθ × IV1) or (It + IV2). Then, a value obtained by adding the standby solenoid current command value Is, that is, (Iθ × IV1) + Is or (It + IV2) + Is is output to the drive mechanism 19 as the solenoid current command value I. The drive mechanism 19 specifies the SOL excitation current A corresponding to the solenoid current command value I and outputs the excitation current A to the solenoid SOL.
[0026]
As described above, since the standby solenoid current command value Is is added, even when the solenoid current command values Iθ and Is based on the steering angle and the steering torque are both zero, the solenoid current command value I is a large value of Is. Keep it. Therefore, the variable orifice a is not completely closed, and a predetermined flow rate is supplied to the steering valve 9 as a standby flow rate. The reason why the standby flow rate is ensured in this way is as follows. That is, from the viewpoint of preventing energy loss, if the required flow rate QM on the power cylinder 8 side is zero, it is ideal that the control flow rate QP of the flow control valve V is also zero. Setting the control flow rate QP to zero means returning the entire amount from the pump P directly to the tank T via the tank port 11. In this case, since the pressure loss of the piping hardly occurs, the driving torque of the pump P is minimized, and an energy saving effect is obtained correspondingly, which is advantageous from the viewpoint of preventing energy loss.
[0027]
Nevertheless, the reason why the standby flow rate is secured is because of the following three advantages.
First, it is for preventing the burn-in of the apparatus. That is, if a certain amount of oil is circulated through the apparatus, a cooling effect by the oil can be obtained. The standby flow rate is for obtaining this cooling function.
Second, it is to ensure responsiveness. That is, if the standby flow rate is ensured as described above, the time required to reach the target control flow rate is shorter than when there is no standby flow rate. Since this time difference becomes responsiveness, the responsiveness can be improved by securing the standby flow rate after all.
[0028]
Third, it is to counter disturbances such as kickback and self-aligning torque. That is, when a drag due to disturbance, self-aligning torque or the like acts on the tire, it acts on the rod of the power cylinder 8. If the standby flow rate is not secured, the tires will fluctuate due to drag due to this disturbance and self-aligning torque. However, if the standby flow rate QP is ensured as described above, even if the drag acts, the tire will not fluctuate. In other words, the rod of the power cylinder 8 is engaged with a pinion for switching the steering valve 9, so that when the drag acts, the steering valve is switched, and the standby flow rate is supplied in a direction against the drag. Will do. Therefore, if the standby flow rate is secured, the disturbance due to the kickback and the self-aligning torque can be countered.
[0029]
A slit 20 is formed at the tip of the spool 1. Even when the spool 1 is at the position shown in the figure, the slit 20 communicates with one pilot chamber 2 and the flow path 6 so that the discharge pressure of the pump P is directed to the steering valve 9 via the slit 20. It is for supply.
This is because the pressure oil is supplied to the steering valve 9 side even if the spool 1 does not move at the illustrated position for some reason.
[0030]
Next, the operation of this embodiment will be described.
For example, when the vehicle is traveling straight on a horizontal road surface, the vehicle keeps traveling straight by self-aligning torque as long as there is no influence of disturbance such as wind. In such a situation, the steering angle is in a substantially neutral position, and almost no steering torque is generated. Therefore, the solenoid current command value Iθ for the steering angle system and the solenoid current command It for the steering torque system are both zero. Therefore, even if these solenoid current command values Iθ and It are multiplied by solenoid current command values IV1 and IV2 based on the vehicle speed, the values remain zero.
[0031]
As described above, since the steering angle system value and the steering torque system value are both zero, the zero value is selected even in the magnitude determination. Since the standby solenoid current command value Is is added to the zero value, the standby solenoid current command value Is is output to the driver 19 as the solenoid current command value I as it is. Thus, if the standby solenoid current command value Is is output as it is, the opening of the variable orifice a is kept to a minimum. Therefore, the standby flow rate is supplied to the steering valve 9 side as the control flow rate QP. That is, the energy consumption of the pump P is suppressed while maintaining a state in which the minimum assist force required during straight traveling can be exhibited.
[0032]
When the steering wheel is steered from the above state, the solenoid current command value Iθ is determined based on the steering angle at that time, and the solenoid current command value It is determined based on the steering torque at that time. The steering angle system solenoid current command value Iθ is multiplied by the solenoid current command value IV1 corresponding to the vehicle speed, and the steering torque system solenoid current command value It is multiplied by the solenoid current command value IV2 corresponding to the vehicle speed. To do.
At this time, if the vehicle speed is in the low speed range, the solenoid current command values IV1 and IV2 based on the vehicle speed are “1”, so the solenoid current command values Iθ and It are output as they are as the multiplied values. On the other hand, if the vehicle speed is in the high speed range, the solenoid current command values IV1 and IV2 based on the vehicle speed are decimal values less than 1, so that the solenoid current command values Iθ and It are small.
[0033]
Therefore, in the high speed range, the assist force that can be exhibited is smaller than in the low speed range, but almost no assist force is required in the high speed range, so there is no inconvenience in steering. If the control flow rate QP is reduced in the high speed region in this way, energy loss can be prevented as much as pressure loss is reduced.
[0034]
Further, the required assist force and the required assist force response vary depending on the steering method and the vehicle speed at that time. For example, the assist force may be small but requires high responsiveness, or the assist force may be large but responsiveness may not be so high. In such a case, it is necessary to determine which condition has priority.
In the first embodiment, in order to determine the above condition, the solenoid current command value Iθ of the steering angle system is compared with the solenoid current command value It of the steering torque system, and the larger value is adopted. I am doing so. When the steering torque system solenoid current command value It is adopted, priority is given to the responsiveness of the assist force. This is because when the steering torque is large, there are many cases that require responsiveness rather than the magnitude of the assist force.
[0035]
Further, when the solenoid current command value Iθ of the steering angle system is adopted, priority is given to the magnitude of the assist force. This is because when the steering angle is large, there are many cases that require a magnitude larger than the responsiveness of the assist force. In any case, if the judgment is made by comparing the conditions of both the steering angle and the steering torque in this way, control according to the actual situation can be performed, and high operability and stability can be ensured.
When the driver actually operates the steering wheel, the control value changes in the order of (1) steering angle → (2) steering angular velocity → (3) operating force (steering torque). Of these, the feedback to the driver is the steering angle and the operating force (steering torque). In the first embodiment, the solenoid current command value I is controlled on the basis of the steering angle and the operating force (steering torque), so that a feedback shift hardly occurs.
[0036]
When the steering wheel is being held, an assist force is required, but generally the steering torque is small. In such a case, normally, the solenoid current command value Iθ for the steering angle system is larger than the solenoid current command value It for the steering torque system, so the control flow rate QP is based on the solenoid current command value Iθ for the steering angle system. Will be controlled.
However, if the solenoid current command value It of the steering torque system becomes larger than the solenoid current command value Iθ of the steering angle system due to reverse input from the power cylinder 8 side, this time, based on the solenoid current command value It of the steering torque system. The control flow rate QP is controlled. In this way, if the steering angle system solenoid current command value Iθ is switched to the control flow rate QP based on the steering torque system solenoid current command value It, there is no shortage of assist force.
[0037]
On the other hand, when the vehicle is traveling straight on an inclined road surface, steering torque is generated by reverse input from the road surface. In this state, if the steering wheel is near the neutral position, the solenoid current command value for the steering angle system is Iθ becomes zero. If the solenoid current command value I is controlled based only on this steering angle system value, the necessary assist force cannot be obtained. As a result, the steering wheel becomes heavy.
However, in the first embodiment, even when the steering angle is in the neutral position, if the steering torque is generated by the reverse input, the control flow rate QP is controlled based on the steering torque, so that the predetermined assist force can be exerted. It becomes a state. Therefore, there is no inconvenience that the steering wheel becomes heavy.
[0038]
Further, if the hand is released with the steering wheel fixed, there is no input from either the steering wheel side or the power cylinder 8 side, so the steering torque becomes zero. However, when the steering wheel is steered from this state, an assist force is required instantly. When operability is required in this way, it is necessary to secure “force” and “responsiveness” sufficient to maintain the operability.
However, in the vicinity of the stationary end, that is, in the state where the steering wheel is steered to the vicinity of the maximum steering angle, the link efficiency of the steering is lowered, so that “force” sufficient to ensure operability cannot always be ensured.
[0039]
However, in the first embodiment, when the stationary release is performed, the solenoid current command value I is controlled based on the steering angle, so that “responsiveness” can be ensured. This is because the time required to reach the required stationary thrust is shortened by the output of the solenoid current command value Iθ corresponding to the steering angle. Since “responsiveness” can be ensured in this way, operability can be kept good.
As described above, the control flow rate QP is controlled based on the steering angle or the steering torque, but only the solenoid current command value Is is always output. Therefore, the standby flow rate is always secured.
Therefore, in any state, the cooling effect of the apparatus can be obtained, and disturbance due to maintenance of responsiveness and kickback can be countered.
[0040]
In the second embodiment shown in FIG. 3, a steering angular velocity is added to the first embodiment as an element for controlling the solenoid current command value I. However, since the method for obtaining the solenoid current command value for the steering angle system and the solenoid current command value for the steering torque system is the same as in the first embodiment, the description thereof is omitted.
In the second embodiment, a steering angular velocity sensor (not shown) is connected to the controller C, and an actual steering angular velocity measured by the steering angular velocity sensor is input to the controller C. In the second embodiment, the actual steering angular velocity is directly obtained by the steering angular velocity sensor. However, the steering angular velocity may be obtained by differentiating the steering angle detected by the steering angle sensor. In this case, a steering angular velocity sensor is not required.
[0041]
When the steering angular velocity signal is input, the controller C specifies the solenoid current command value Iω based on the steering angular velocity. This solenoid current command value Iω is determined on the basis of a theoretical value in which the relationship between the steering angular velocity and the control flow rate QP is linear. However, the solenoid current command value Iω is set to zero if the steering angle is equal to or less than the set value. The solenoid current command value Iω for the steering angular velocity may be stored in advance in the controller C as a table value, or may be calculated by the controller C each time based on the steering angle.
[0042]
When the solenoid current command value Iω is obtained based on the steering angular speed as described above, the solenoid current command value IV3 based on the vehicle speed signal is used as a limit value for this value, and the solenoid current command value Id for the steering angular speed system is output. Therefore, the solenoid current command value IV3 based on the vehicle speed signal outputs 1 when the vehicle speed is in the low speed range without reducing the response, and outputs a decimal value less than 1 in the high speed range.
Therefore, although the solenoid current command value Id also decreases according to the vehicle speed, the upper limit is cut by the limit value unlike the solenoid current command value Iθ of the steering angle system and the solenoid current command value It of the steering torque system. The output responsiveness of the steering current system solenoid current command value Id where responsiveness is regarded as important is not lowered.
[0043]
When the steering angular velocity system solenoid current command value Id is obtained as described above, the steering angular velocity system solenoid current command value Id, the steering angular system solenoid current command value (Iθ × IV1), and the steering torque system solenoid. The current command value (It × IV2) is compared and the largest value is selected. Then, the standby solenoid current command value Is is added to the largest selected value.
Therefore, any one of (Iθ × IV1) + Is, (It + IV2) + Is, and Id + Is is output to the drive mechanism 19 as the solenoid current command value I. The drive mechanism 19 specifies the SOL excitation current A corresponding to the solenoid current command value I and outputs the excitation current A to the solenoid SOL.
[0044]
According to the second embodiment, since all the factors that occur when the steering wheel is operated, such as the steering angle, the steering angular velocity, and the operation force (steering torque), are considered as control values, feedback deviation Can be resolved further. Further, by adopting the steering angular velocity as a determination factor, it is possible to further improve the responsiveness.
[0045]
【The invention's effect】
  ThisAccording to the invention, the steering angle, the steering torque,Steering angular velocity andSince the control flow rate supplied to the steering valve is controlled based on the vehicle speed, it is possible to perform control suitable for the actual vehicle running conditions and steering conditions.. ThisThus, the flow rate control according to the actual situation can be performed, so that the torque for driving the pump P does not increase more than necessary, and the energy loss can be minimized.In addition, since the solenoid current command value is controlled based on all the control values generated when the steering wheel is operated, that is, the steering angle, the steering angular velocity, and the steering torque, it is possible to further eliminate the feedback deviation. Further, the response can be improved by using the steering angular velocity as the control value.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of an embodiment.
FIG. 2 is an explanatory diagram showing a control system of a controller C of the first embodiment.
FIG. 3 is an explanatory diagram showing a control system of a controller C of a second embodiment.
[Explanation of symbols]
I Solenoid current command value
Iθ Solenoid current command value by steering angle
It solenoid current command value by steering torque
Iω Solenoid current command value by steering angular velocity
IV1 Solenoid current command value by vehicle speed
IV2 Solenoid current command value by vehicle speed
IV3 Solenoid current command value by vehicle speed
QP control flow rate
QT return flow rate
QM required (necessary) flow rate
B body
P Pump port
a Variable orifice
SOL solenoid
C controller
T tank
1 spool
2 One pilot room
3 The other pilot room
4 Pump port
5 Spring
8 Power cylinder
9 Steering valve
16 Steering angle sensor
17 Steering torque sensor
18 Vehicle speed sensor

Claims (1)

A steering valve for controlling the power cylinder, a variable orifice provided on the upstream side of the steering valve, a solenoid for controlling the opening of the variable orifice, a controller for controlling a solenoid current command value I for driving the solenoid, The steering angle sensor, steering torque sensor, steering angular velocity sensor, and vehicle speed sensor connected to this controller , and the flow rate supplied from the pump, the control flow rate leading to the steering valve according to the opening of the variable orifice, and the return to the tank A flow rate control valve for distributing the flow rate to the flow rate. The controller includes a solenoid current command value Iθ corresponding to a steering angle from a steering angle sensor, a solenoid current command value It corresponding to a steering torque, and a steering angular velocity sensor. Calculate the solenoid current command value Iω according to the steering angular velocity or On the other hand, the solenoid current command value Iθ for the steering angle system and the solenoid current command value It for the steering torque system are respectively multiplied by solenoid current command values IV1 and IV2 set based on the vehicle speed, and the steering angular velocity The solenoid current command value Iω of the system uses the solenoid current command value IV3 set based on the vehicle speed as a limit value, and the calculated solenoid current command value Id of the steering angular velocity system and the solenoid current command value of the steering angle system and comparing the magnitude of the solenoid current instruction value of the steering torque based, power steering device, characterized in that the most size have values selected to solenoid current instruction value I.

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