JPS6325179A - Power steering device - Google Patents

Abstract

PURPOSE:To arrange an optimum power assist by driving a hydraulic pump only when required according to steering conditions by means of an electric motor and at the same time producing oil pressures according to steering and restoration forces by utilizing results of a neutral position detection means for controlling the oil pressures. CONSTITUTION:A hydraulic pump 53 is driven by an electric motor 61 rotating according to a drive signal V5 from a control circuit 62. To the control circuit 62 are inputted signals V1, V3, To and NH respectively from a steering force sensor 63, a vehicle speed sensor 64, an oil temperature sensor 65 and a neutral position sensor 66. The neutral position sensor 66 is mounted on a steering device 35 to detect the neutral position of a rod 42. According to the detected result of the aforementioned sensor, a hydraulic pump 53 is driven only when required by means of the electric motor 61.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a power steering device, and more particularly, to a power steering device that provides power assist to a vehicle such as an automobile.

(Conventional technology) As automobiles become more popular, especially in urban areas, it has become inevitable to use them in poor parking and garage environments. is also increasing. Reducing the driver's burden leads to less fatigue, which means more margin for safe driving.

As the width of tires increases, the steering force itself tends to increase. Against this background, so-called power steering devices have recently been installed in vehicles from the viewpoint of maneuverability and stability, and their use has become remarkable.

The purpose of power steering is to reduce the burden on the driver regarding steering, and the various functions required include reduction of steering force, feedback of appropriate reaction force in response to steering, and smooth steering. Furthermore, it is also required that the power required for devices that implement these various functions be small.

As a conventional power steering device applied to this type of power steering device, there are, for example, the following two types of power steering devices, and these will be explained below with reference to FIGS. 12 and 13.

(Hydraulic type (see Figure 12)) In Figure 12, 1 is a handle, and the steering force of the handle 1 is transmitted to a hydraulic servo valve 3 via a steering shaft 2, and also to a steering gear mechanism 4. In the steering gear mechanism 4, the rotational displacement of the handle 1 is converted into a linear displacement of the rod 5, and this linear displacement is transmitted from a predetermined linkage mechanism 7 to the steering wheel 8 via the hydraulic cylinder 6. is steered according to the rotational displacement of the handle 1.

On the other hand, the hydraulic servo valve 3 receives the discharge pressure from the hydraulic pump 11 that is constantly driven by the engine 10, and the hydraulic servo valve 3 controls switching of the discharge hydraulic pressure supplied to the hydraulic cylinder 6 according to the steering direction of the handle 1. The piston of the hydraulic cylinder 6 is moved by applying so-called hydraulic pressure to the operation to increase the steering force. Note that 12 is a return tank.

(Problem to be Solved by the Invention) However, in such hydraulic type devices, the hydraulic pump is driven by the power of the engine, and the direction and pressure of the discharge amount of the pump are controlled by a hydraulic servo valve to perform steering. Since the structure is such that the feeding power to the hydraulic cylinder of the device is assisted, there are the following problems.

b) Since the hydraulic pump is driven by an engine, it is necessary to provide a flow control valve to control the flow rate.

Since the pump is driven to discharge a large flow rate even at high speeds where power assistance is not required, engine power loss is large.

c) High-precision machining is required for the servo valve that performs hydraulic control, resulting in high costs.

2) In order to set the hydraulic characteristics, special edge machining is required for the spool valve in the hydraulic servo valve. in this case,
There are limits to processing, and there are also limits to the degree of freedom in properties.

e) Since it is a mechanical hydraulic control, there is a limit to implementing control suitable for vehicle driving conditions.

f) Because the road reaction force is canceled by the flow resistance of the hydraulic oil, the steering wheel may not return smoothly to the neutral position.

On the other hand, in order to overcome some of the drawbacks of the hydraulic type as described in (1) above, the following motor-driven pump type has been proposed.

(■) Motor-driven pump type (see FIG. 13) In FIG. 13, the displacement of the steering shaft 2 is detected by the steering switch 21 and input to the control circuit 22. The control circuit 22 controls the output of the electric motor 23 based on this detection information, that is, the information that the steering wheel 1 has been steered, and the driving of the electric motor 23 drives the hydraulic pump 11 similar to the above (1) hydraulic pump method. be done.

However, in the case of such a motor-driven pump type, disadvantages (a) and (b) of the above-mentioned hydraulic type are overcome, but the pump drive is turned on and off by an electric motor.
F? The conventional hydraulic servo valve is used for pressure control, and the above-mentioned drawbacks in this respect cannot be overcome.

(Objective of the Invention) Therefore, the present invention generates hydraulic pressure according to the steering force and restoring force by driving the hydraulic pump with an electric motor only when necessary according to the steering condition and the position of the steering mechanism. The aim is to provide power assistance and restore the vehicle to a neutral position, as well as improve the ease of installation of the device and reduce the power required for power assistance.

(Means for Solving the Problems) In order to achieve the above object, the power steering system according to the present invention, as shown in FIG. a neutral position detection means for detecting a neutral position of a steering mechanism operated by the steering wheel; and a discriminating means C for determining the steering direction and steering force of the steering wheel based on the output of the steering state detection means;
A control means d that calculates an output control value to an electric motor that drives a hydraulic pump according to the steering direction and steering force of the steering wheel, and calculates an auxiliary restoring force value of the steering wheel based on the output of the neutral position detection means; An electric motor e that outputs a driving force according to an output control value and a restoring force auxiliary value from the means.
, a hydraulic pump f that is driven by an electric motor and generates hydraulic pressure corresponding to the output of the electric motor, and a hydraulic actuator g that generates auxiliary power that assists the steering force and restoring force of the steering wheel based on the discharge pressure from the hydraulic pump. It is equipped with.

(Function) In the present invention, the steering direction of the steering wheel, the steering force, and the neutral position of the steering mechanism are detected, and the hydraulic pump is driven by the electric motor only when necessary according to these detection results.

Therefore, appropriate hydraulic pressure is generated according to the steering force, providing appropriate power assistance, restoring to the neutral position, improving the ease of installing the device,
The required power can be reduced.

(Example) Hereinafter, the present invention will be explained based on the drawings.

2 to 10 are diagrams showing a first embodiment of the present invention, and are examples in which the present invention is applied to a power steering device for a vehicle such as an automobile.

First, the configuration will be explained. In FIG. 2, 31 is a steering wheel, and the steering force T)I of the steering wheel 31 is transmitted via a steering shaft 32 to a pinion 34 that constitutes a part of a steering device 33. The pinion 34 is rotatably supported by bearings 36 and 37 fixed to the housing 35, and its central portion meshes with the rack 38. Therefore, when the handle 31 is steered, the pinion 34 rotates and the rank 38 is engaged with it, causing the rank 38 to move left and right in the figure. That is, the rotational displacement of the handle 31 is converted into a linear displacement of the rank 38. The pinion 34, housing 35, bearings 36, 37, and rack 38 constitute a steering device 33. In addition,
39 is a dust seal.

A hydraulic cylinder 41 is integrally disposed on the right side of the steering device 33 in the figure, and the hydraulic cylinder 41 has a rod 42 formed integrally with the rank 38. A piston 43 is fixed to the rod 42.
is slidably movable within the outer cylinder 44 of the hydraulic cylinder 41. Further, the inside of the outer cylinder 44 is divided into an A chamber 45 and a B chamber 46 by a piston 43, and each chamber 45, 46
A seal 47, 48 is provided on each side. Each chamber 45.46 is connected to a main oil passage 51.52 via a port 49.50, respectively.
52 is connected to a hydraulic pump 53 which can be rotated in forward and reverse directions. Branch oil passages 54 are provided in the middle of each of the main oil passages 51 and 52.
．． 55 are connected, and branch oil passages 54 and 55 are connected to an oil tank 56. A check valve 67.68 and a fixed throttle 59.6 are provided in the middle of each of these branch oil passages.
0 is provided, and the fixed throttles 59 and 60 create a pressure difference before and after the fixed throttles when the hydraulic oil passes through them.

The hydraulic pump 53 is driven by an electric motor 61, and the electric motor 61 is rotated by a drive signal 5 from a control circuit 62. The control circuit 62 receives signals V+ from a steering force sensor (steering condition B detection means) 63, a vehicle speed sensor 64, an oil temperature sensor 65, and a neutral position sensor (neutral position detection means) 66.
, V3, TO, and NH are input.

The steering force sensor 63 is attached to the steering shaft 32 and detects the direction and magnitude of the steering force of the steering wheel 31. Devices that detect such steering force include, for example, a strain gauge type that detects the amount of strain caused by torque as an electrical quantity, a potentiometer type that electrically detects the amount of displacement caused by torque, or a torsional displacement type. A device using a Hall element that detects the amount of change in the magnetic field is used. In addition, as a device for detecting the steering angle,
For example, a method is used in which light passing through a slit in a rotating plate is detected as a pulse signal.

The vehicle speed sensor 64 detects the vehicle speed (vehicle speed) V3.
- Something to detect, such as a speedometer signal. The oil temperature sensor 65 is provided in the middle of a passage connected to the oil tank 56, and detects the temperature To of the hydraulic oil.

Further, the neutral position sensor 66 is provided in the steering device 33 and detects the neutral position of the rod 42.

The control circuit 62 has functions as a determination means and a control means, and is configured by a microcomputer. Then, the control circuit 62 calculates processing values necessary for steering force assistance and restoring force assistance of the vehicle according to a program stored therein, and outputs drive signals (1) and (7) to the electric motor 61 as necessary.

The electric motor 61 generates rotational force according to the drive signals (1) and (2) to rotate the hydraulic pump 53 in the normal or reverse direction. The hydraulic pump 53 is of a type capable of forward and reverse rotation, and generates hydraulic pressure corresponding to the rotational driving force of the electric motor 61, and supplies it to the hydraulic cylinder 41 through main oil passages 51 and 52. The hydraulic cylinder 41 moves the piston 43 linearly from side to side in the figure in response to the oil pressure supplied to each chamber 45, 46, and steers the steering wheel 68 via a linkage mechanism 67 connected to the loft 42.

The hydraulic cylinder (including the piston and outer cylinder) 41, the rod 42, the main oil passage 51.52, the branch oil passage 54.55,
Oil tank 56, check valve 57, 58 and fixed throttle 5
9.60 constitutes a hydraulic actuator 69 as a whole, and the hydraulic actuator 69 generates the steering force T of the handle 31 and auxiliary power for assisting the restoring force based on the discharge pressure from the hydraulic pump 53. .

FIG. 3 is a block diagram showing the overall configuration described above.

In this figure, the application of steering force T□ by the driver via the steering wheel 31 is detected by the steering force sensor 62,
The steering force sensor 63 uses this as a signal ■ to the control circuit 62.
Output to. The control circuit 62 includes a signal amplification processing circuit 71, an arithmetic circuit (such as a CPU) 72, and a motor drive circuit 73. The signal amplification processing circuit 71 amplifies the signal (2) by the necessary amount and outputs it to the arithmetic circuit 72 as the signal (2).

Further, the calculation circuit 72 receives as other inputs a vehicle speed signal 3 from the vehicle speed sensor 64, an oil temperature signal To, and a signal Ni from the neutral position sensor 66. Arithmetic circuit 72
Based on these signals (2), (3), To, and No, outputs a signal (4) necessary for controlling the steering force assist of the vehicle and a signal v6 necessary for restoring the steering wheel to the motor drive circuit 73 in accordance with the above-mentioned program. The motor drive circuit 73 outputs to the motor 61 signals Vs and V7, which are converted to levels necessary to drive the motor 61 based on the signals V4 and (2). The electric motor 61 rotates forward or reverse in response to the signals ■3 and ■7, and the hydraulic pump 53 generates a hydraulic pressure P corresponding to the driving force of the electric motor 61 to drive the steering device 33 including the hydraulic cylinder 41 (hydraulic actuator in this figure). 69) to generate the auxiliary force F. Then, this auxiliary force F is detected again by the steering force sensor 63 and the neutral position sensor 66 as a rotational displacement of the steering shaft 32, and feedback control is performed so that the steered wheels are steered to a desired position and then restored to the neutral position. be done.

Next, the effect will be explained.

FIG. 4 is a flowchart showing a steering force and restoring force assistance program executed by the control circuit 62. This program is executed once every predetermined time.

First, at P, the steering force TH1 of the steering wheel 31, the vehicle speed ■5, the oil temperature To, and the neutral position NH are read. Next, the output (1) of the steering force sensor 63 representing the steering force T is converted and amplified to obtain a signal (2). At P, the current steering force conversion value ■2 is set to a predetermined value ■. Compare with.

Here, the predetermined value ■. is set to a value that corresponds to the case where the steering force TI (of the steering wheel 31) is extremely small and so-called power assist is not required. It has become.

■2≧■. In this case, it is determined that power assist is necessary, and the steering direction (steered direction) is determined in P4. signal V2
represents the steering direction and the magnitude of the steering force; ■, >0 indicates that the vehicle is being steered to the right, and ■, 2×0, indicates that the vehicle is being steered to the left.

■When 2>0, P is the control signal when steering to the right.
4 is calculated, and when V2<0, the control signal -■4 at the time of left steering is calculated at P4.

As shown in FIG. 5, the control signals 14 and -V4 are set so as not to assist the steering within a certain range from the start of steering, taking into account the amount of play in the steering wheel. When the certain range is exceeded, the value (also an absolute value) increases as the steering force conversion value (2) increases (increases in absolute value).

When P or P6 is obtained, the control signal +V4 corresponding to the above-mentioned calculation result is outputted to the electric motor 61 in response to V4, and the drive signal ■ is outputted to the electric motor 61 in response to V4. Control signal 10V4, -V
4 and the drive signal V, as shown in FIG. 6, has linearity, but this characteristic may be set arbitrarily depending on the control mode.

Further, in this step P7, a correction is made based on the information of the aforementioned vehicle speed (3). This correction value is specifically shown in FIG. 10, which will be described later.

In this way, the control signal V1, - which is differentiated into positive and negative values, is
Since the drive signal ■ is outputted to the electric motor 61 based on the signal V4, the electric motor 61 rotates at a rotation speed N corresponding to the steering direction and the magnitude of the steering force as shown in FIG.
3 in forward or reverse rotation. As a result, the hydraulic pump 53 is driven in accordance with the rotation speed N of the electric motor 61,
A pump discharge IJQ as shown in FIG. 8 is generated and supplied to the hydraulic actuator 69.

On the other hand, in step P3 above, V, <V. In this case, it is determined that there is no need to assist the steering force T of the steering wheel 31, and P,
to determine whether steering has ended. The neutral position N indicates whether the steering mechanism 33 is in the neutral position.
When the answer is No-0, it is determined that the steering mechanism 33 is in the neutral position and there is no need to output the restoring assisting force, and the current routine is ended. Therefore, in this case, drive signals V5 and V, which will be described later, are not output, and no power is supplied to the electric motor 61. This means that it is not necessary to constantly generate hydraulic pressure to drive the hydraulic actuator 69 when there is no need to perform power assist. Incidentally, with conventional hydraulic hole types, the hydraulic pump rotates even when power assist is not performed. Therefore, this leads to a reduction in driving power.

Further, in step P, if NH=O, it is determined that it is necessary to assist the restoring force, and in step P, the direction is determined based on 2 input in the previous routine. ■2 represents the steering direction and steering force, and when ■2>0, it means that the steering direction will be restored (return) to the left direction, which is opposite to the steering direction.
When , it indicates that the image is restored to the right.

■When 2>0, PIo is the control signal when restoring the left.
V6 is calculated, and when V2<Q, the control signal 6 is calculated at the time of right restoration in one mouth.

P. Alternatively, after passing through Pl+, the drive signal 7 is outputted to the electric motor 61 in response to the control signals 1V, , -V, corresponding to the above-mentioned calculation results at p+z. The V7 exhibits characteristics such that the weaker the road reaction force is, and the closer the vehicle is to a shake-off, the greater the restoring assist force becomes.

Further, in this step p+z, a correction is made based on the information of the aforementioned vehicle speed (2). Since the restoring force increases as the vehicle speed increases, this correction value reduces the restoring assisting force as the vehicle speed increases.

In this way, the drive signal V is output based on the control signals 10V, , -V6, and the motor 61 is output in accordance with the drive signal 7.
outputs the rotational speed N. The electric motor 61 drives the hydraulic pump 53 in forward or reverse rotation at the rotation speed NN, and the hydraulic pump 53 generates a pump discharge amount Q corresponding to the rotation speed N of the electric motor 61 and supplies it to the hydraulic actuator 69.

In this way, the hydraulic cylinder 41 slides left and right in FIG. 2 by the hydraulic oil discharged from the hydraulic pump 53 driven by the electric motor 61 that rotates in response to the drive signal (2) or V7. Main oil passage 51 in hydraulic pump 53
When this is set as the discharge side, the hydraulic oil flows into the A chamber 45, passes through the branch oil passage 54 and the fixed throttle 59, and enters the oil tank 5.
Return to 6. On the other hand, the main oil passage 52 is on the suction side, and the hydraulic oil passes through the check valve 58, the fixed throttle 60, and the branch oil passage 55, and is sucked into the hydraulic pump 53 again by the main oil passage 52. At this time, the rod 42 is connected to the piston 43.
is moved to the right in the figure by receiving hydraulic pressure, and the steering force and restoring force are assisted. On the other hand, when the discharge side and the suction side are reversed, the passage route of the hydraulic oil is reversed.

In the above case, when the hydraulic oil discharged by the hydraulic pump 53 passes through the fixed throttle 59 or 60, a pressure difference occurs before and after the throttle. ), pressure PD is generated on the upstream side.

This pressure PD is determined by the flow rate Q passing through the fixed throttle 59 or 60, and its characteristics in the case of steering force assistance are determined by the 9th
As shown in the figure, the pump discharge rate tends to increase rapidly as the pump discharge rate increases.

In addition, the fixed throttle 59.60 and the flow rate Q are approximately hydraulic pump 5.
Since the discharge flow rate is 3, this flow rate Q is equal to the pump rotation speed N
(=motor rotational speed), and this characteristic is as shown in FIG. 8 above.

On the other hand, as the hydraulic fluid passes through each member constituting the hydraulic actuator 69, its viscosity changes under the influence of frictional heat, outside temperature, and the like. At this time, if the fixed throttle 59.60 that generates the hydraulic pressure PD is an orifice, it is less susceptible to changes in viscosity, but the oil passages before and after the fixed throttle 59.60 are affected by viscosity.

Therefore, even if the discharge flow rate of the hydraulic pump 53 is constant, the oil pressure PD changes depending on the temperature. Generally, when the temperature of the hydraulic oil increases, the hydraulic pressure PD decreases, and conversely, when the temperature of the hydraulic oil decreases, the hydraulic pressure PD increases. As a result, the hydraulic actuator 69 cannot provide power assistance corresponding to the rotational speed N of the electric motor 61. Therefore, the output of the oil temperature sensor 65 is changed to the control circuit 6.
2 as data and using this data information for feedback control of the discharge pressure, the desired hydraulic pressure PD is output.

Therefore, power assist according to the steering force TI, vehicle speed V, oil temperature To, and neutral position N is applied by the hydraulic actuator 77 when the steering or handle returns.

Based on the above-mentioned effects, the effects of this embodiment will be compared with the conventional example from the viewpoints of problems (a) to (f) above.

(A) Since the hydraulic pump 53 is driven by the electric motor 61 only when power assistance is required depending on the steering wheel 31, the hydraulic pump 53 is stopped when the vehicle is not being steered. In addition to this, the pump can also be stopped regardless of the steering force, for example in high speed ranges where power assist is not required, resulting in no loss of engine power and a significant energy saving effect.

This means that the problem (b) above is solved.

(B) Hydraulic servo valves and flow control valves that require precision machining as in the past are no longer required, and all control can be performed electrically. Therefore, the above problems (a), (c), (
d) can be resolved.

(C) Electrical control makes it possible to easily create steering characteristics that are optimal for various vehicle running conditions.

Therefore, the above problem (e) can be solved.

(D) By power-assisting the restoring force of the steering wheel, it is possible to restore the vehicle to the neutral position according to various driving conditions. Therefore, the above-mentioned problem can be solved.

Next, FIG. 11 is a diagram showing a second embodiment of the present invention.

This embodiment is an example in which the direction of hydraulic oil supplied to the hydraulic cylinder 41 is controlled by an electromagnetic direction switching valve 83. 11th
In the figure, a cylinder oil passage 81.82 is connected to the hydraulic cylinder 41 via a port 49.50, and the cylinder oil passage 81.82 is connected to an electromagnetic directional control valve 83. The electromagnetic directional control valve 83 has solenoids 33a and 83 at both ends.
The solenoids 83a and 83b are driven by a drive signal from a control circuit 90, which will be described later. A supply oil passage 84 and a return oil passage 85 are connected to the electromagnetic directional switching valve 83 , and the supply oil passage 84 and the return oil passage 85 are connected to a hydraulic pump 86 . The electromagnetic directional switching valve 83 switches the mutual connection between the cylinder oil passages 81 and 82 and the supply oil passage 84 in response to the drive signal, thereby changing the flow direction of the hydraulic oil. A fixed throttle 87 is disposed in the middle of the supply oil passage 84 and the return oil passage 85, and the fixed throttle 87 generates a pressure difference before and after the hydraulic oil when it passes therethrough. Also,
An oil tank 88 is disposed in the middle of the return oil path 85. The hydraulic pump 86 is driven by an electric motor 89,
Electric motor 89 is rotated by a drive signal from control circuit 90 .

Note that the oil pump 86 and electric motor 89 are those that rotate in a constant direction.

Therefore, when signals are input to the control circuit 90 from the steering force sensor 63, vehicle speed sensor 64, oil temperature sensor 65, and neutral position sensor 66, the control circuit 90 outputs control values for the electromagnetic directional control valve 83 and the electric motor 89. is calculated and a drive signal is output. This drive signal causes the electromagnetic directional control valve 8 to
No. 3 solenoid 83a or solenoid 83b is driven, and the electromagnetic directional switching valve 83 is switched. Further, the electric motor 89 is driven by the control signal, and the output of the electric motor m89 drives the hydraulic pump 86.

The hydraulic oil discharged from the hydraulic pump 86 generates pressure by a fixed throttle 87, and the pressure is transferred from the boats 49, (50) through the supply oil line 84, the electromagnetic direction switching valve 83, and the cylinder oil lines 81, (82). It is transmitted to each chamber of the cylinder 41. In this case, the hydraulic oil discharged from the cylinder 41 flows through the cylinder oil passages 81, (82) and the electromagnetic directional control valve 83.
and is sucked into the hydraulic pump 89 through the return oil path 85. In this way, it is possible to perform power assist according to the steering force and restoring force, and it is possible to obtain the same effects as in the first embodiment.

Note that since the hydraulic pump 86 and the electric motor 89 can rotate in one direction, the device can be made smaller and lighter.

The other configurations and operations are the same as in the previous embodiment.

(Effects) According to the present invention, the hydraulic pump is driven by an electric motor only when necessary according to the steering condition, and the result of the neutral position detection means is used for control, so that the hydraulic pump is driven according to the steering force and restoring force. Appropriate power assistance can be achieved by generating hydraulic pressure. As a result, it is possible to improve the steering feeling, improve the ease of mounting the device, and reduce the power required for power assist.

[Brief explanation of drawings]

Fig. 1 is a basic conceptual diagram of the present invention, Figs. 2 to 10 are diagrams showing a first embodiment of the invention, Fig. 2 is an overall configuration diagram thereof,
Fig. 3 is a block diagram thereof, Fig. 4 is a flowchart showing the steering force and restoring force assistance program, Fig. 5 is a diagram showing the characteristics of the control signal, and Fig. 6 is a diagram showing the characteristics of the drive signal. , FIG. 7 is a diagram showing the characteristics of the motor rotation speed, FIG. 8 is a diagram showing the characteristics of the pump discharge amount, FIG. 9 is a diagram showing the oil pressure in relation to the pump discharge amount, and FIG. A diagram showing the oil pressure in relation to the steering force, FIG. 11 is an overall configuration diagram showing a second embodiment of the present invention, and FIGS. 12 and 13 are diagrams for explaining a conventional power steering system. 1st
Figure 2 is a schematic configuration diagram showing the hydraulic power steering system.
FIG. 3 is a schematic configuration diagram showing the motor-driven pump type power steering device. 53...Hydraulic pump, 61...Electric motor, 62...Control circuit (discrimination means, control means), 6
3...Steering force sensor (steering state detection means), 6
6... Neutral position sensor (neutral position detection means),
67...Hydraulic actuator. Figure 9 Figure 10 Saikuwa Kento sword

Claims (1)

[Scope of Claims] a) Steering state detection means for detecting the steering state of the steering wheel; b) Neutral position detection means for detecting the neutral position of a steering mechanism operated by the steering wheel; and c) Output of the steering state detection means. d) determining means for determining the steering direction and steering force of the steering wheel based on the steering direction and the steering force; a control means that calculates a restoring force auxiliary value of the steering wheel based on the output; e) an electric motor that outputs a driving force according to the output control value and the restoring force auxiliary value from the control means; A hydraulic pump that generates hydraulic pressure corresponding to the output of the electric motor, and g) a hydraulic actuator that generates auxiliary power that assists the steering force and restoring force of the steering wheel based on the discharge pressure from the hydraulic pump. Power steering device.