JPH0747969A - Steering device with automatic steering mechanism - Google Patents

Abstract

PURPOSE:To reconcile the position control of an automatic steering mechanism and the pressure control of a power steering mechanism, in a steering system with an automatic steering mechanism which is made up so as to switch steerage by the automatic steering mechanism over to the artificial one and vice versa. CONSTITUTION:This steering system is provided with a steering wheel system 36, a steering force transmitting system 3 having a steering input part 2 to be displaced according to a rotational displacement of this steering wheel system 36 and steering a steering wheel, and an automatic steering force setting means 13 setting automatic steering force necessary for a car according to running conditions and circumstances of the car, respectively. Likewise it is provided with an automatic steering mechanism 5 automatically steering the steering wheel by way of adding the automatic steering force to the steering input part 2, and it is formed so as to make the steering wheel steerable in displacing the steering input part 2 according to a resultant between the artificial steering force and the automatic steering force inputted into the steering input part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device with an automatic steering mechanism, which is suitable for use in an automatic driving system for vehicles such as automobiles, and more particularly to using a power steering mechanism as a component of the automatic steering mechanism. A suitable steering device with an automatic steering mechanism.

[0002]

2. Description of the Related Art In recent years, in a steering mechanism of an automobile, various sensors are provided on the vehicle, a steering angle control signal is set based on information from these sensors, and the steering mechanism is positively operated by hydraulic pressure or an electric motor. In addition, many automatic steering mechanisms that automatically steer have been proposed.

[0003]

By the way, steering control (position control by rack position) and force control (hydraulic power steering mechanism) required for a steering device (steering system) including such an automatic steering mechanism. In the case of (2), it is difficult to satisfy both pressure control), and there is a problem that its practical application is difficult.

The present invention was devised in view of the above-mentioned problems, and includes a steering force control system such as a power steering mechanism and an input system of an artificial steering force for an unmanned automatic steering. It is an object of the present invention to provide a steering device with an automatic steering mechanism, which is connected in parallel to enable both position control and pressure control of the steering mechanism.

[0005]

Therefore, the steering device with an automatic steering mechanism according to the present invention is provided in a vehicle and has a steering wheel system that is rotationally displaced by inputting an artificial steering force. A steering input unit that is interposed between the steering wheel system and a steering wheel and that is displaced according to a rotational displacement of the steering wheel system, and the steering angle is set to a steering angle according to the displacement of the steering input unit. A steering force transmission system for steering wheels, and a steering force for automatic steering, which is provided in parallel with the steering wheel system and includes a steering direction and a steering force required for the vehicle according to a traveling state and a traveling environment of the vehicle. And an automatic steering mechanism for automatically steering the steered wheels by applying a steering force for the automatic steering to the steering input section so as to displace the steering input section. , The steering input unit in the steering force transmission system is displaced according to the resultant force of the artificial steering force and the automatic steering force input to the steering input unit to steer the steered wheels. It is characterized by being configured.

A steering device with an automatic steering mechanism according to a second aspect of the present invention is, in addition to the configuration according to the first aspect,
The steering input unit includes a power steering mechanism that assists the steering force according to the steering state when the artificial steering force is input, and the automatic steering mechanism applies the steering force for automatic steering through the power steering mechanism. And an automatic steering operation state in which the power steering mechanism is operated in response to the artificial steering force and an automatic steering operation is performed in accordance with the automatic steering mechanism. Is provided with a switching mechanism that selectively switches between the two.

A steering device with an automatic steering mechanism according to a third aspect of the present invention is, in addition to the configuration of the second aspect,
Artificial steering force detection means for detecting the magnitude and direction of the artificial steering force input to the steering input section, steering input information detected by the artificial steering force detection means, and the automatic steering steering If it can be determined from the automatic steering information set by the force setting means that the required amount of steering has not been performed in the direction in which the steered wheels are to be steered, the power steering mechanism is changed from the steering assist operation state to the automatic steering. And a control means for controlling the switching mechanism so as to switch to a normal operation state.

According to a fourth aspect of the present invention, in addition to the structure of any one of the first to third aspects, the steering device with an automatic steering mechanism according to the present invention further comprises the artificial input to the steering input section. An artificial steering force detection means for detecting the magnitude and direction of the steering force is provided, and the automatic steering force setting means detects the artificial steering force detection means during the operation of the automatic steering mechanism. Steering force reducing means for reducing the steering force for automatic steering when the artificial steering force is continuously applied for a predetermined time so as to oppose the steering of the automatic steering, based on the steering input information. It is characterized by

According to a fifth aspect of the present invention, in addition to the structure of any one of the first to third aspects, the steering device with an automatic steering mechanism according to the present invention further comprises the artificial input to the steering input section. An artificial steering force detecting means for detecting the magnitude and direction of the steering force is provided, and the automatic steering steering force setting means is provided by the automatic steering mechanism during the operation of the automatic steering mechanism. On the basis of the opposing force between the steering force for steering and the artificial steering force detected by the artificial steering force detecting means, the greater the opposing force, the smaller the steering force for automatic steering and the smaller the opposing force. It is characterized in that the steering force is set corresponding to the opposing force so as to increase the steering force for automatic steering.

According to a sixth aspect of the present invention, there is provided an automatic steering mechanism-equipped steering device according to any one of the third to fifth aspects, wherein the artificial steering force detecting means includes the steering wheel. A torque sensor that is interposed between the steering force transmission system and the steering force transmission system and detects a torsional torque corresponding to the magnitude of the artificial steering force input to the steering input unit. It has a feature.

A steering device with an automatic steering mechanism according to a seventh aspect of the present invention is provided with a vehicle speed detecting means for detecting a vehicle speed of the vehicle, in addition to the configuration according to any one of the first to sixth aspects. While the automatic steering mechanism is operating, the steering force applied by the steering force setting means for automatic steering is reduced based on the vehicle speed information detected by the vehicle speed detection means in accordance with the increase of the vehicle speed. It is characterized in that a vehicle speed corresponding adjustment means for adjusting the steering force for automatic steering is provided.

Further, in the steering apparatus with an automatic steering mechanism according to the present invention as defined in claim 8, in addition to the structure according to any one of claims 1 to 7, the automatic steering mechanism is provided with the steering force for automatic steering. It is characterized in that a steering force level setting means for automatic steering that can artificially set the level of the steering force for automatic steering set by the setting means is provided.

[0013]

In the steering apparatus with automatic steering mechanism according to the first aspect of the present invention, when an artificial steering force is input to the steering wheel system, the steering wheel system and the steering input section are rotationally displaced, and steering is performed. The steered wheels are steered to a steering angle according to the displacement of the steering input unit via the force transmission system.

Further, the automatic steering steering force setting means of the automatic steering mechanism provided in parallel with the steering wheel system sets the automatic steering steering force required for the vehicle according to the traveling state and traveling environment of the vehicle. . Then, the steering force for automatic steering is applied to the steering input section, the displacement is given to the steering input section, and the steered wheels are automatically steered. Then, the steering input section in the steering force transmission system is displaced according to the resultant force of the artificial steering force and the automatic steering force input to the steering input section to steer the steered wheels.

In the steering apparatus with automatic steering mechanism according to the second aspect of the present invention, the steering force for automatic steering is applied to the automatic steering mechanism through the power steering mechanism, whereby automatic steering is performed. Further, when the artificial steering force is input to the steering input unit, the power steering mechanism assists the steering force according to the steering state. Then, by controlling the switching mechanism, the power steering mechanism selects one of a steering assist operating state in which the steering mechanism operates according to an artificial steering force and an automatic steering operating state in which the power steering mechanism operates according to the automatic steering mechanism. Can be switched.

In the steering apparatus with automatic steering mechanism according to the third aspect of the present invention, the magnitude and direction of the artificial steering force input to the steering input section from the artificial steering force detecting means are detected. Then, the control means steers the steered wheels in the direction to be steered from the steering input information detected by the artificial steering force detection means and the automatic steering information set by the automatic steering steering force setting means. When it is determined that the power steering mechanism is not operating, the switching mechanism is controlled to switch the power steering mechanism from the steering assist operating state to the automatic steering operating state.

In the steering apparatus with automatic steering mechanism according to the present invention as described above, the magnitude and direction of the artificial steering force input to the steering input section is detected by the artificial steering force detecting means, and the automatic steering force is automatically detected. By the steering force reducing means provided in the steering force setting means for steering, the artificial steering force opposes the automatic steering based on the steering input information from the artificial steering force detecting means during the operation of the automatic steering mechanism. When continuously performed for a predetermined time, the steering force for automatic steering is reduced.

In the above steering apparatus with automatic steering mechanism according to the present invention, the magnitude and direction of the artificial steering force input to the steering input section is detected by the artificial steering force detecting means, and the automatic steering force is automatically detected. By the steering force setting means for steering, based on the opposing force between the steering force from the automatic steering mechanism and the artificial steering force detected by the artificial steering force detecting means during the operation of the automatic steering mechanism, the greater the opposing force, The steering force for automatic steering is set small, and the steering force for automatic steering is set large as the opposing force is small.

In the above steering apparatus with automatic steering mechanism according to the present invention, the torque sensor interposed between the steering wheel and the steering force transmission system is used as the artificial steering force detecting means. The torque sensor detects the torsional torque corresponding to the magnitude of the artificial steering force input to the steering input section. In the steering apparatus with an automatic steering mechanism according to the present invention as set forth in claim 7, the vehicle speed of the vehicle is detected by the vehicle speed detecting means, and the vehicle speed detected by the vehicle speed detecting means while the automatic steering mechanism is operating by the vehicle speed correspondence adjusting means. Based on the information, the steering force for automatic steering is adjusted so that the steering force applied by the steering force setting means for automatic steering becomes smaller as the vehicle speed increases.

In the above steering apparatus with automatic steering mechanism according to the present invention, the automatic steering force setting means provided in the automatic steering mechanism sets the automatic steering force set by the automatic steering steering force setting means. The level of the steering force for steering is artificially set, and the steering force can be changed according to the driver's preference.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. First, a steering device with an automatic steering mechanism as a first embodiment of the present invention will be described. FIG. 1 is a hydraulic circuit diagram schematically showing the hydraulic system thereof, and FIG. 2 is a schematic diagram of the control system of the automatic steering mechanism. FIG. 3 is a flow chart for explaining the action, and FIG. 4 is a map for explaining the action.

As shown in FIG. 1, the vehicle is provided with a steering wheel system 36 including a steering wheel (handle) 28 and a steering shaft 28A, and a driver normally operates the steering wheel to input a steering force. The steered wheels (not shown) of the vehicle are steered according to the rotational displacement angle of the steering wheel. The steering force transmission system 3 is provided between the steering wheel system 36 and the steered wheels. This steering force transmission system 3
For example, in the case of a rack and pinion type steering mechanism, the steering rack 2 is provided as a steering input unit that meshes with a pinion provided at the output end on the steering shaft 28A side to form a rack and pinion mechanism.

Further, the steering force transmission system 3 of the vehicle is provided with a power steering mechanism 4 for giving an input through the steering rack 2. When the driver inputs the steering force to the steering wheel 28, the steering state of the vehicle is set. The steering force is assisted accordingly. The power steering mechanism 4 is configured as a hydraulic power steering mechanism that assists the steering force with hydraulic pressure.
By supplying hydraulic oil having a hydraulic pressure corresponding to the driver's steering to the hydraulic cylinder 4A of the power steering mechanism 4,
The steering force of the driver can be reduced by energizing the movement of the steering rack 2 which is the steering input unit.

For this reason, the vehicle is provided with an oil pump 10 driven by the engine 9, and the oil pump 10 sucks hydraulic oil from the oil tank 11. The hydraulic fluid discharged from the oil pump 10 is branched into two directions by the flow dividing valve 12. One of these oil passages is connected to a known power steering valve such as the EPS valve 15 or the like, and the EPS valve 1
The hydraulic state of the hydraulic cylinder 4A is adjusted through 5.

The EPS valve 15 is an electronically controlled power steering control valve. This electronically controlled power steering device will be briefly described. For example, a vehicle speed sensor or the like is provided in the vehicle, and a valve (EPS) capable of adjusting the hydraulic pressure supplied to the power steering is provided in a part of the hydraulic system of the hydraulic power steering device. A valve 15) and the like are provided. Then, based on the information detected by the vehicle speed sensor or the like, the operation of the EPS valve 15 or the like is EC
U (Electronic Control Unit) 17
The electronic control makes it possible to adjust the steering assist amount.

The vehicle is provided with an automatic steering mechanism 5 in parallel with the steering wheel system 36, and the power steering mechanism 4 is used to perform automatic steering. The structure of the automatic steering mechanism 5 will be described in detail later. Further, in this vehicle, the power steering mechanism 4 is operated in accordance with the artificial steering force (steering force from the driver) for steering assist, and the automatic steering mechanism 5 is operated in accordance with the set steering force. A mode switching valve 8 is provided as a switching mechanism for switching between the steering operation state.

Then, for example, when the automatic steering mechanism 5 detects an obstacle or the like in the traveling direction of the vehicle, the mode switching valve 8 is activated to automatically steer the vehicle. During such automatic steering, a required steering force is applied to the steering rack 2 as a steering input section by the automatic steering mechanism 5 so that the required steering is automatically performed against the operation of the steering wheel 28. Has become. By doing so, it is possible to avoid obstacles.

As shown in FIG. 1, the automatic steering mechanism 5 is provided with an EPS valve 15 of the power steering mechanism 4 and a steering angle control valve (automatic steering control valve) 7 provided in parallel with this hydraulic system. The other of the diversion valves 12 is connected to the steering angle control valve 7. This steering angle control valve 7
It is a valve for controlling the steering force during automatic steering. By operating this control valve 7, it is possible to supply hydraulic oil of a predetermined hydraulic pressure to the hydraulic cylinder 4A during automatic steering.

The mode switching valve 8 is provided between the steering angle control valve 7 and the hydraulic cylinder 4A and between the EPS valve 15 and the hydraulic cylinder 4A. In addition, reference numerals 14 and 16 in the drawing indicate a solenoid and a return spring, respectively. The mode switching valve 8 sets the power steering mechanism 4 to a steering assist operation state (steering assist mode) for assisting the steering force according to the steering force from the steering wheel 28, or
It is for switching whether to set the operating state for automatic steering (automatic steering mode) that operates according to the set steering force of the automatic steering mechanism 5. By driving this mode switching valve 8, the steering state is switched. Has become.

The mode switching valve 8 is normally set to the steering assist mode. In this case, the hydraulic oil supplied to the EPS valve 15 is the mode switching valve 8
It is supplied to the hydraulic cylinder 4A through the passage to reduce the steering force. The steering angle control valve 7 is also configured as a solenoid valve like the relief valve 13 and the mode switching valve 8.

The automatic steering mechanism 5 will now be described. The automatic steering mechanism 5 includes a power steering mechanism 4, a relief valve 13 and a controller 1 as a control means. An automatic steering steering force setting means 1A for setting an automatic steering steering force (or simply an automatic steering force) consisting of a steering direction and a steering force is further provided, and a drive circuit 24 as a steering force reducing means is additionally provided. Has been done.

The drive circuit 24 converts a control command voltage V based on the steering force set by the automatic steering force setting means 1A of the controller 1 into a current A supplied to the solenoid 14 of the relief valve 13. Further, a relief valve 13 is provided between the oil pump 10 and the flow dividing valve 12. The relief valve 13 is configured as a solenoid valve that is operated by a solenoid 14, and is normally pressed by a return spring 16 in the right direction in the drawing to close the valve. Then, when hydraulic oil having a pressure higher than a predetermined hydraulic pressure is supplied to the steering angle control valve 7 and the EPS valve 15, the relief valve 1
3 is driven to the left in the figure against the return spring 16 by the solenoid 14, so that the hydraulic oil is transferred to the oil tank 1.
It is supposed to be returned to 1. As a result, the operating oil pressure of the steering angle control valve 7 and the EPS valve 15 is reduced. Therefore, the magnitude of the steering force is set depending on the open / close state of the relief valve 13.

The open / closed state of the relief valve 13 is controlled by the current A from the drive circuit 24. Further, the steering angle control valve 7 and the mode switching valve 8 are also controlled by the controller 1. That is, the steering angle control valve 7 is controlled based on the steering direction set by the automatic steering steering force setting means 1A of the controller 1.

The controller 1 is provided with an automatic steering judging means 18 for controlling the mode switching valve 8. The automatic steering determination means (hereinafter simply referred to as determination means) 18 includes a sensor group 1 including various sensors.
9 are connected to the sensor group 19 shown in FIG.
CCD camera 18A and laser radar 18B as shown in
And these pieces of information are sent to the judging means 18.

In addition to the sensor group 19, a torque sensor 19A as an artificial steering force detecting means is connected to the judging means 18. This torque sensor 19A is
Specifically, the steering force is provided on the steering shaft 28A of the steering wheel system 36, and the steering force input to the steering force transmission system 3 by the steering angle control valve 7 and the artificial force input to the steering wheel 28 so as to resist it. The torsional torque generated by the dynamic steering force is detected. Since this torsional torque corresponds to the difference between these two opposing forces (opposite force), this opposing force is detected. Equivalent to.

Then, the judging means 18 determines the necessary amount in the direction in which the steered wheel should be steered from the steering input information detected by the torque sensor 19A and the automatic steering force set by the automatic steering steering force setting means 1A. It is designed to determine whether or not the vehicle is being steered. When the controller 1 determines that the necessary amount of steering has not been performed by the determination means 18, the controller 1 outputs a command signal to the mode switching valve 8 to switch the power steering mechanism 4 from the steering assist mode to the automatic steering mode. Has become.

By the way, as shown in FIG.
An image processing unit 18C, an information control unit 18D, and an inter-vehicle distance determining unit 18E are provided inside the vehicle. Then, the information from the CCD camera 18A and the laser radar 18B is processed as an image by the image processing section 18C and displayed on the display 18H installed in the vehicle.

The judgment means 18 is connected to the threshold value storage means 18F, the voice guidance means 18G and the display 18H. Further, when a warning is issued by voice or display, the driver is alerted by the voice guide means 18G or display 18H.
Then, in the judging means 18, for example, the driver does not operate the steering wheel 28 in accordance with the steering information detected by the torque sensor 19A, even though the vehicle is approaching the object, and If the deceleration is not sufficient, it is determined that the automatic steering is performed, and the determination means 1
An automatic steering operation command signal is output from the controller 8 to the controller 1.

At this time, for example, the following formula (1) is used as a criterion for determining the switching to the automatic steering. Then, this detects the collision risk,
Determine whether to warn the driver with a voice or display, or to perform automatic steering control. _{V 0 · t G -X G V} · t G 2/2> d 0 ····· (1) Incidentally, V ₀ a vehicle speed of the vehicle, t _G is the deceleration required time, X
_G V is the required deceleration at the vehicle speed V ₀ , and d ₀ is the distance from the vehicle to the approaching object.

Then, the controller 1 drives the mode switching valve 8 according to the information from the judging means 18 to switch to the automatic steering mode. As a result, the hydraulic pressure from the EPS valve 15 is cut off and the hydraulic cylinder 4A
Is supplied with hydraulic oil from the steering angle control valve 7. Further, the automatic steering mechanism 5 is provided with a feedback section 5B together with the controller 1, and the feedback section 5B is provided with a rack position detection sensor 20 for detecting the position of the rack 2 of the power steering mechanism 4.

The information from the rack position detection sensor 20 is fed back to the command signal from the controller 1 to control the steering angle control valve 7.
In the automatic steering mode, the steered wheels (hereinafter referred to as steered wheels) are steered by positively supplying hydraulic oil of a predetermined pressure to the hydraulic cylinder 4A. When the steering wheel 28 is steered, the hydraulic pressure can be overcome to steer the steered wheels.

Since the steering apparatus with the automatic steering mechanism as the first embodiment of the present invention is constructed as described above, the mode switching valve 8 is set so as not to perform the automatic steering during the normal operation. Therefore, the vehicle is steered by the steering force input to the steering wheel 28 from the driver while being assisted by the power steering mechanism 4.

At this time, the mode switching valve 8 is in a state as shown in FIG. 1 (that is, the valve 8 is urged rightward in the figure by the urging force of the return spring 16).
Controlled by. Therefore, the hydraulic path from the steering angle control valve 7 to the hydraulic cylinder 4A of the power steering mechanism 4 is cut off, and the EPS valve 15 and the hydraulic cylinder 4A are in communication with each other.

As a result, the hydraulic oil supplied to the EPS valve 15 is supplied to the hydraulic cylinder 4A via the mode switching valve 8. Therefore, when the driver operates the steering wheel 28, the EPS ECU 17 controls the EPS valve 15 according to the state of the vehicle,
The steering force is assisted. Then, the steered wheels are steered according to the steering state (according to the steering displacement of the steering wheel 28) when the driver manually inputs the steering force,
The steering force transmission system 3 is steered by the steering assist mode of the power steering mechanism 4.

Further, when the vehicle is approaching an object such as an obstacle in the traveling direction, according to the flow chart shown in FIG.
Determine whether to guide by voice or automatic steering. Then, the information control unit 18D and the vehicle distance determination unit 1
In 8E, for example, it is determined whether to perform automatic steering according to the flowchart shown in FIG.

That is, first, the distance d _{0 of the} approaching object from the vehicle is read based on the information from the CCD camera 5B and the laser radar 5C (step S1). Then, the relative speed from the difference [Delta] d ₀ of the short time Δt seconds before the reading distance d ₀ 'and the current reading distance d ₀ vehicle and the object V _R0
Is calculated (step S2). And this relative speed V
_{From R0} , it is determined whether or not the vehicle is approaching the object (step S3). When it is determined that the vehicle is not approaching the object, the process returns to step S1 again, and steps S1 to S3 are performed.
repeat.

If the vehicle is approaching the object, the vehicle speed V ₀ of the vehicle is read (step S4), and thereafter, the map provided in the threshold value storage means 18F (FIG. 4).
The required deceleration X _G V at the vehicle speed V ₀ is read from (shown in FIG. 5) (step S5). This map shows the distance d
And shows the relationship between the vehicle speed V ₀ required deceleration X _G V at _0, line a in the figure shows the threshold when the distance d _0.

Then, the deceleration required time t _G is calculated from the relative speed V _R0 and the required deceleration X _G V (step S6), and the collision risk is determined by the above-mentioned equation (1) (step S7). ). If the formula (1) is not satisfied, the process returns to step S1. If the formula (1) is satisfied, it is determined whether the driver should be warned by voice or a display, or the automatic steering control should be performed.

As a result, even if the driver does not perform proper steering due to carelessness or the like, the controller 1 carries out automatic steering and controls such as danger avoidance. Then, when automatic steering is performed, a command signal is output from the determination means 18 to the controller 1. Then, the mode switching valve 8 is driven to the left side in FIG. 1 to switch to the automatic steering mode.

As a result, the hydraulic pressure from the EPS valve 15 is cut off, and the steering angle control valve 7 is attached to the hydraulic cylinder 4A.
The hydraulic oil is supplied from. The steering state at this time is detected by the rack position detection sensor 20. Then, the feedback unit 5B controls the open / closed state of the steering angle control valve 7 by feeding back the information from the rack position detection sensor 20 to the command signal from the controller 1.

Therefore, at the time of automatic steering, the steered wheels are steered by position control according to the position of the rack 2. As described above, in the present device, the mode switching valve 8 can achieve both the force control by the normal power steering mechanism 4 and the position control by the position of the rack 2 during automatic steering.

The open / closed state of the relief valve 13 is
It is controlled by the drive circuit 24. Then, in the drive circuit 24, the control command voltage V from the controller 1 is converted into the current A, and the relief valve 13 is converted according to the current A.
By driving, the hydraulic pressure of the hydraulic oil is kept constant. Further, when the driver inputs the steering force to the steering wheel 28 in the automatic steering mode, when the steering force is larger than the hydraulic pressure of the hydraulic fluid, the steering wheel can be steered by overcoming the hydraulic pressure.

As a result, when the driver steers during automatic steering, the steering can be performed while receiving the hydraulic resistance of the hydraulic oil against the steering force input to the steering wheel 28. Further, in the automatic steering mode, the position control of the rack 2 close to the actual steering angle is performed, not the control by the steering angle of the steering wheel 28. Therefore, accurate control can be performed, and the rattling of the steering force transmission system 3 can be prevented. Direct control can be performed without being affected by the above.

Further, the present apparatus can be installed in a vehicle at low cost by using the conventional power steering mechanism 4. Next, a second embodiment of the present invention will be described. FIG. 5 is a hydraulic circuit diagram schematically showing the hydraulic system. The steering wheel system 36 shown in FIG. 1 is omitted in the hydraulic circuit diagrams of FIG. 5 and subsequent figures.

In the second embodiment, while the oil pump 11 of the first embodiment is constructed to be driven by the engine 9, as shown in FIG. 5, an electric motor 22 and an electric motor 22 are used. Electric hydraulic pump 2 driven
It is designed to be pressurized by 3 and. The output of the electric motor 22 is controlled by the current A from the drive circuit 24, whereby the hydraulic pressure of the hydraulic oil discharged from the electric hydraulic pump 23 is always kept at a predetermined hydraulic pressure. You can do it.

In this embodiment, the structure other than the above is the same as that of the first embodiment, and the description thereof is omitted here. Since the steering apparatus with the automatic steering mechanism as the second embodiment of the present invention is configured as described above, in this hydraulic system, the electric hydraulic pump 23 is driven by the electric motor 22.
Is driven to supply hydraulic oil.

Further, since the electric motor 22 is controlled according to the current A from the drive circuit 24, the electric hydraulic pump 23 acts in the same manner as the relief valve 13 and the output hydraulic pressure of the hydraulic oil is always kept constant. . Then, through the controller 1, the mode switching valve 8, the power steering mechanism 4, and the automatic steering mechanism 5, the same effect as that of the above-described first embodiment can be obtained. Furthermore, by controlling the electric motor 22 by the controller 1 as described above, there is an advantage that the relief valve 13 becomes unnecessary and the entire apparatus can be made smaller and lighter.

Next, a third embodiment of the present invention will be described. FIG. 6 is a hydraulic circuit diagram schematically showing the hydraulic system.
FIG. 7 is a flow chart for explaining the operation, FIG.
Is a map for explaining the action. As shown in FIG. 6, the third embodiment is configured almost the same as the first embodiment, and only the control system of the relief valve 13 is different.

As in the first embodiment, the automatic steering mechanism 5 is provided with a drive circuit 24A, and the relief valve 13 is controlled to be opened and closed by the drive circuit 24A. As a result, the hydraulic pressure of the hydraulic oil supplied to the mode switching valve 8 and the steering angle control valve 7 is adjusted. Further, the drive circuit 24A is adapted to convert the control command voltage V set by the steering force setting means 1A for automatic steering of the controller 1 into the current A. At the time of this conversion, the command gain V of the current A is converted by the instruction gain k. The size is adjusted. Therefore, the magnitude of the steering force set by the automatic steering force setting means 1A of the controller 1 is adjusted according to the instruction gain k in the drive circuit 24A.

Further, this apparatus is provided with an artificial steering force detecting means 19A for detecting the amount of steering force input to the steering wheel 28. The artificial steering force detecting means 19A is specifically the torque sensor as described above. And in the controller 1,
Based on the detection information from the artificial steering force detection means 19A, the magnitude of the artificial steering force that opposes the steering force of the automatic steering mechanism 5 is equal to or larger than a predetermined amount, and
When this state continues for a predetermined time, the instruction gain k is set and the drive circuit 24A is controlled so that the magnitude of the steering force by the automatic steering mechanism 5 gradually decreases.

That is, in order for the driver to steer the steering wheel 28 against the automatic steering mechanism 5 in the automatic steering mode, a steering force that overcomes the hydraulic pressure of the hydraulic oil supplied to the hydraulic cylinder 4A is required. If the hydraulic pressure of the hydraulic oil is kept constant, it is conceivable that the driver will be burdened with a large steering force against the hydraulic pressure. Therefore, even in the automatic steering mode, it is desired that the steering force of the automatic steering mechanism 5 does not impose a heavy burden on the driver when the driver intends to perform steering.

In the third embodiment, when the steering force is input to the steering wheel 28 during the automatic steering by the controller 1 described above, the operating hydraulic pressure of the automatic steering mechanism 5 is gradually reduced to reduce the steering force of the driver. The burden is reduced. That is, in the drive circuit 24A, the command voltage V from the controller 1 is converted into the current A according to the operating oil pressure instruction gain k, and the hydraulic pressure adjustment of the operating oil pressure of the relief valve 13 is performed according to the operating oil pressure instruction gain k described later. It is performed by controlling the open / closed state.

Since the steering system with the automatic steering mechanism as the third embodiment of the present invention is configured as described above, the driver applies the steering force to the steering wheel 28 against the automatic steering in the automatic steering mode. When input, the artificial steering force detecting means 19A detects this steering force. Then, in the controller 1, the artificial steering force amount detecting means 19
The instruction gain k of the relief valve 13 is determined based on the information of A.

This operating oil pressure command gain k is determined, for example, according to the flow chart shown in FIG. Explaining this flowchart, first, it is determined whether or not the magnitude (absolute value) of the steering force Hf input to the steering wheel 28 by the artificial steering force amount detecting means 19A is larger than 5 kgf (step SA1).

The steering force Hf is 5 kg.
When it is larger than f, 1 is added to the timer count value T in step SA2 and the process proceeds to step SA4. The timer count value T is initially set to 0 at the start of automatic steering. Moreover, the magnitude of the steering force is 5 kgf.
In the following cases, the process proceeds from step SA1 to step SA3. Then, in step SA3, the timer count value T is decremented by 1, and the process proceeds to step SA4.

Next, the timer count value T is 100
It is determined whether or not it is larger (step SA4).
If it is larger than 100, the process proceeds to step SA5 and the timer count value T is set to 100. Then, the operating oil pressure instruction gain k when T is 100 is read from the map shown in FIG. 8 (step SA6).

When the timer count value T is 100 or less in step SA4, the process proceeds to step SA7. Then, in step SA7, it is determined whether the timer count value T is negative. And the timer count value T
Is determined to be negative, this timer count value T
Is reset to 0 (step SA8), and step SA6
Proceed to. If the timer count value T is not negative, the process directly proceeds to step SA6.

Then, in step SA6, the operating oil pressure command gain k is read from the map shown in FIG.
Then, in the drive circuit 24, this operating oil pressure instruction gain k
The command voltage V is converted into a current A according to the above, and the relief valve 13 is controlled. As a result, when the steering force is input to the steering wheel 28 against the automatic steering, the automatic steering mechanism 5 responds to the operating hydraulic pressure instruction gain k.
The operating oil pressure is gradually reduced, and the driver's burden of steering force is reduced.

That is, when an artificial steering force is input to the steering wheel 28 during automatic steering, first (T = 0
(Between 30 and 30), the steering wheel 28 cannot be operated against the automatic steering mechanism 5 unless a large steering force is input, but if the steering force is further input,
The steering force by the automatic steering mechanism 5 gradually becomes small (between T = 30 to 100), and thereafter keeps a small constant value (T = 100).
It is possible to artificially steer without requiring too much force.

The magnitude of the steering force shown in the flowchart of FIG. 7 is not limited to 5 kgf, but may be set to an appropriate value in consideration of the steering force of the driver. Further, the characteristic of the map that determines the operating oil pressure instruction gain k is not limited to that shown in FIG. 8 and may be another characteristic. Next, a fourth embodiment of the present invention will be described. FIG. 9 is a hydraulic circuit diagram schematically showing the hydraulic system.

In the fourth embodiment, the hydraulic system of the third embodiment is constructed so that it is pressurized by the oil pump 11 driven by the engine 9 as in the first embodiment.
As shown in FIG. 9, as in the second embodiment, the electric motor 22
And an electric hydraulic pump 23 driven by the electric motor 22. The output of the electric motor 22 is controlled according to the command voltage V set by the controller 1, whereby the hydraulic pressure of the hydraulic oil discharged from the electric hydraulic pump 23 is always a predetermined hydraulic pressure. It is adjusted to.

Therefore, in this automatic steering mechanism 5, the relief valve 13 as in the third embodiment is omitted. That is, in the controller 1, the determination means 1
The control command voltage V is set on the basis of the information from 8 and actuated on the basis of the information from the artificial steering force amount detecting means 19A (that is, the steering force input to the steering wheel 28, the steering force input time, etc.). Oil pressure instruction gain k
Is set.

Then, the drive circuit 24 causes the command voltage V
Is converted into a current A according to the operating oil pressure instruction gain k,
The output of the electric motor 22 is adjusted. The fourth embodiment has the same configuration as that of the third embodiment except for the difference in the above-mentioned constituent elements, and therefore the description thereof will be omitted here.

Since the steering system with the automatic steering mechanism according to the fourth embodiment of the present invention is configured as described above, in addition to the same effect as the third embodiment, the hydraulic pressure of the hydraulic oil is changed to the electric motor 22. The adjustment by the output control of 1 eliminates the need for the relief valve 13 and has the advantage of reducing the size and weight of the entire apparatus. Next, a fifth embodiment of the present invention will be described. FIG. 10 is a hydraulic circuit diagram schematically showing the hydraulic system, and FIG. 11 is a map for explaining its operation.

In the fifth embodiment, as shown in FIG. 10, the structure is substantially the same as that of the third embodiment. That is,
A drive circuit 24B is provided in the automatic steering mechanism 5, and the open / close state of the relief valve 13 is controlled through the drive circuit 24B. And
As a result, the hydraulic oil is adjusted to a predetermined hydraulic pressure.

In the fifth embodiment, in addition to the third embodiment, a steering force level setting means 26 is provided in the automatic steering mechanism 5 and is connected to the controller 1. The steering force level setting means 26 can artificially set the magnitude of the steering force by the automatic steering mechanism 5 (steering force level) to a desired state.

As a result, when the driver steers the steering wheel 28 against the automatic steering during the automatic steering, the burden of the steering force can be arbitrarily adjusted according to the driver's preference. . The steering force level setting means 26 is configured as, for example, a variable volume switch. Then, the steering force level setting means 26 changes the steering force at the time of automatic steering according to the map as shown in FIG.

The horizontal axis of the map shown in FIG. 11 shows the set gain k1 corresponding to the volume of the variable volume switch, and the vertical axis shows the hydraulic pressure P of the hydraulic oil during automatic steering.
Then, the setting gain k1 is artificially set, whereby the steering force setting means 1A for automatic steering of the controller 1 is set.
The magnitude of the steering force set by can be adjusted, and the automatic steering mechanism 5 is operated by the hydraulic pressure according to the set gain k1.

If the set gain k1 is set too small, the hydraulic pressure of the hydraulic oil may drop too much and the hydraulic cylinder 4A may not be driven during automatic steering. Therefore, the relationship between the setting gain k1 and the operating oil pressure P is such that the hydraulic pressure lower limit P0 shown in FIG. 11 is secured so that the hydraulic pressure P0 that can drive the hydraulic cylinder 4A can be secured even if the setting gain k1 is the lowest value. It is a graph that does.

Then, in the drive circuit 24B, the control command voltage V set by the controller 1 is converted into the current A according to the set gain k1 set by the steering force level setting means 26 and the operating oil pressure command gain k. It is like this. Then, the relief valve 13 is controlled according to the current A, and the working oil is adjusted to have a predetermined hydraulic pressure.

Since the steering system with the automatic steering mechanism as the fifth embodiment of the present invention is configured as described above, when the steering by the automatic steering mechanism 5 is against the driver's intention, the driver automatically performs the steering operation. By steering the steering wheel 28 with a force larger than the hydraulic pressure of the mechanism 5,
It is possible to perform artificial steering by the driver. The hydraulic pressure of the hydraulic oil at this time is the steering force level setting means 2
Since it can be set in advance by setting 6,
When the driver is tired or the force is not so strong, the automatic gain control mechanism 5 can be set by setting the setting gain k1 small.
The operating hydraulic pressure of can be lowered.

As a result, even when the automatic steering mechanism 5 is in operation, when the steering is contrary to the driver's intention, the steering wheel 28 can be steered with a comparatively small force, and steering by the driver's intention is possible. have priority. Further, the relationship between the set gain k1 and the oil pressure P is not limited to the characteristics of the control map shown in FIG. 11, but may be any other characteristics as long as the characteristics can ensure the lower limit value P0 of the oil pressure. Can be applied.

Next, a sixth embodiment of the present invention will be described. FIG. 12 is a hydraulic circuit diagram schematically showing the hydraulic system. In the sixth embodiment, the hydraulic pressure of the fifth embodiment is pressurized by the oil pump 11 driven by the engine 9, while as shown in FIG.
The hydraulic fluid is pressurized by the electric motor 22 and the electric hydraulic pump 23.

The output of the electric motor 22 is controlled by the drive circuit 24B, whereby the hydraulic pressure of the hydraulic oil discharged from the electric hydraulic pump 23 is adjusted. In the drive circuit 24B, the control command voltage V set by the controller 1 is set by the steering force level setting means 26 by the set gain k1.
The output of the electric motor 22 is adjusted by converting the current A into a current A according to the operating hydraulic pressure instruction gain k.

In this embodiment, the structure other than the above is the same as that of the fifth embodiment, and therefore the description thereof is omitted here. Since the steering system with the automatic steering mechanism as the sixth embodiment of the present invention is configured as described above, the hydraulic pressure of the hydraulic oil is preset by the steering force level setting means 26 as in the fifth embodiment. Therefore, for example, when the driver is tired or the force is not so large, the hydraulic pressure of the automatic steering mechanism 5 can be lowered by setting the set gain k1 small. As a result, even when the automatic steering mechanism 5 is operating, the steering wheel 28 can be steered with a comparatively small force when the steering is against the driver's intention, and the driver's intention is prioritized.

The electric motor 22 has a drive circuit 24B.
The relief valve 13 is not necessary because it is adjusted in accordance with the current A from, and there is an advantage that the size and weight of the entire apparatus can be reduced. In each of the above-described embodiments, the automatic steering is automatically switched in an emergency, but the device is not limited to those in these embodiments. For example, on a road. If normal steering by automatic steering can be performed based on a white line or a signal such as a beacon installed on the road, the mode switching valve 8 as a switching mechanism can be switched by a manual switch. The automatic steering and the manual steering may be selected according to the driver's preference.

Next, a steering system with an automatic steering mechanism as a seventh embodiment of the present invention will be described. FIG. 13 is a schematic configuration diagram focusing on its functional configuration, and FIG. 14 shows the characteristic of the automatic steering force. It is a graph shown. When the driver consciously operates the steering wheel against the automatic steering during the automatic steering, if the steering force of the automatic steering is too large, the steering force of the driver will be defeated by the automatic steering force and the steering will be performed as the driver desires. It is possible that the

In this embodiment, the steering wheel 2
When an artificial steering force that opposes the automatic steering is input to 8, the steering force of the automatic steering is controlled so that the artificial steering force easily overcomes the automatic steering. Further, the hydraulic system such as the hydraulic circuit of the automatic steering system is configured as shown in any of the above-described first to sixth embodiments, for example.

As shown in FIG. 13, the power steering mechanism 4 is provided with a rack position detection sensor 20, which detects the position of the rack 2 to determine the actual steering angle,
That is, the actual steering state is detected.
A steering wheel angle sensor 31 is provided on the steering wheel (handle) 28, and the steering wheel angle sensor 31 detects the steering wheel angle.

Reference numeral 32 is a steering wheel angle gain setting means. In the steering wheel angle gain setting means 32, the steering wheel angle signal b is set by multiplying the steering wheel angle information from the steering wheel angle sensor 31 by the steering wheel angle gain k0. The deviation (= a) between the actual steering angle signal a corresponding to the actual steering angle from the rack position detection sensor 20 and the artificial steering angle signal b corresponding to the magnitude of the artificial steering force from the steering wheel angle sensor 31. -B) is calculated. This allows
The difference between the steering force of automatic steering and the steering force of driver steering is calculated.

By the way, generally, the steering wheel angle and the rack 2
The amount of movement corresponds to the other, and if either the steering wheel angle or the rack position is known, the other information can be known. However, for example, the above-described first to sixth embodiments
When both the power steering mechanism 4 and the automatic steering are made compatible by using a hydraulic operating system such as the above and a torsion bar 33 as shown in FIG. 13 on the steering shaft, the driver resists the automatic steering during the automatic steering. When the handle is operated, the torsion bar 33 is twisted,
The correspondence between the steering wheel angle and the rack position is no longer established.

Therefore, in this embodiment, by utilizing such characteristics, when the driver operates the steering wheel during the automatic steering, the automatic operation is performed based on the detection information from the steering wheel angle sensor 31 and the rack position detection sensor 20. The difference between two opposing forces of the steering force and the driver steering force is calculated, and when the automatic steering force is larger than the driver steering force, the automatic steering force is set small so that the driver can easily overcome the automatic steering. It is supposed to be done. Further, when the deviation between the automatic steering force and the driver steering force is small, the automatic steering force is set to be large.

That is, in the automatic steering force setting means 1A of the controller 1, when the driver steering force is input during automatic steering, this is fed back to newly set the automatic steering force. Is there. Since both the automatic steering and the power steering mechanism 4 are hydraulic type mechanisms, in the present embodiment, the change of the steering force is realized by changing the automatic steering oil pressure.

As shown in FIG. 13, this device is provided with a controller 1, and the controller 1 has an automatic steering for setting a steering force for automatic steering (consisting of steering direction and steering force) as a control target. The steering force setting means 1A is provided, and particularly, the automatic steering force is set based on the opposing force between the driver's artificial steering force and the automatic steering steering force.

The automatic steering force setting means 46 has a map of automatic steering pressure characteristics as shown in FIG. 14, for example, and the automatic steering force is set according to the characteristics of this map. ing. In this map, the larger the deviation signal ab (the deviation between the actual steering angle signal due to automatic steering and the artificial steering wheel angle signal according to the magnitude of the artificial steering force), the smaller the automatic steering pressure is set. It has become so.

As a result, even if the artificial steering force is small, the automatic steering force is set to a small value accordingly, so that the artificial steering can be performed without requiring a large force during the automatic steering. Of. Reference numeral 34 is a gain changeover switch as a steering force level setting means for automatic steering, 35 is an amplifier, and the amplifier 35 amplifies the steering force signal set by the steering force setting means 46 for automatic steering, for example, automatic steering. This steering force signal is transmitted as an electric signal to the steering angle control valve 7 (see FIG. 1) as a means.

The gain changeover switch 34 sets the gain of the steering force signal set by the automatic steering force setting means 46. The gain changeover switch 3
4, it is possible to artificially set the level of the steering force for automatic steering set by the steering force setting means for automatic steering (here, the relief valve) 13.
For example, the gain changeover switch as the steering force level setting means for automatic steering will be specifically described. Two gains k1 and k2 having different magnitudes can be set according to the driver's preference.

The gain k2 is smaller than the gain k1, and by selecting the gain k2 by the gain changeover switch 34, even a person with a relatively weak arm such as a woman or an elderly person can surely overcome the automatic steering. Is able to. Since the steering system with an automatic steering mechanism according to the seventh embodiment of the present invention is configured as described above, two forces that oppose the automatic steering force from the actual steering angle and the driver steering force from the steering wheel angle. Is detected, the automatic steering force is controlled accordingly, and the automatic steering force is set so that the driver can easily overcome.

That is, when the driver steers during automatic steering, the steering wheel angle sensor 31 detects the steering wheel angle of the driver steering and the rack position sensor 2
When 0, the actual steering angle by automatic steering is detected. Further, the detected steering wheel angle signal has the gain k0 set by the steering wheel angle gain setting means 32 and is output as the steering wheel angle signal b.

Then, the deviation of two opposing forces is calculated from the actual steering angle (actual steering angle signal a) and the steering wheel angle signal b. Then, the automatic steering force setting means 46 sets the automatic steering force according to the difference between the actual steering angle signal a and the steering wheel angle signal b. The characteristic of the automatic steering force is set according to the map shown in FIG.

The automatic steering force signal set by the automatic steering force setting means 46 includes the gain changeover switch 34.
In, the gain k1 or the gain k2 is set. Thereafter, the steering force signal is amplified by the amplifier 35,
The control signal is transmitted to the relief valve 13, the steering angle control valve 7, and the like. Therefore, when the driver operates the steering wheel against the automatic steering during the automatic steering, the steering operation is likely to overcome the automatic steering according to the steering force of the driver, and the steering intention by the driver can be prioritized. it can.

Further, by providing the gain change-over switch 34, even a woman or an elderly person who has a comparatively weak arm strength can overcome the automatic steering. In the present embodiment, the "actual steering angle signal a-steering wheel angle signal b" is used as the parameter indicating the two opposing force magnitudes of the automatic steering and the driver steering. Is not limited to this, and for example, the twist amount of the torsion bar 33 detected by the torque sensor 19A may be directly detected and used.

Next, the eighth embodiment of the present invention will be described. FIG. 15 is a hydraulic circuit diagram schematically showing the hydraulic system, and FIG. 16 is a graph showing the characteristic of the automatic steering force. In the hydraulic circuit of the automatic steering device, the hydraulic pressure for automatic steering can be shared as the hydraulic pressure for the four-wheel steering (4WS) device and the automatic braking device. As shown in FIG. The released hydraulic oil is divided into
One of them is supplied to the 4WS device (mainly the hydraulic cylinder on the rear wheel side) via 2. Further, an oil passage is further branched on the downstream side of the flow dividing valve 12, so that the working hydraulic pressure is supplied to two systems of an automatic braking device and an automatic steering device.

Of these, FIG. 15 is a hydraulic circuit diagram in the automatic steering device, in which reference numeral 27 is a hydraulic source switching valve, reference numeral 7 is a steering angle control valve as an automatic steering means, and reference numeral 15 is an EPS valve. By driving the hydraulic pressure source switching valve 27 to switch the hydraulic pressure path, the hydraulic oil from the pump 10 is supplied to either the steering angle control valve 7 or the EPS valve 15.

Further, reference numeral 8 is a mode switching valve which can be switched in conjunction with the hydraulic power source switching valve 27, and the EPS valve 15 is controlled by the mode switching valve 8.
It is possible to switch between one of the steering assist mode by and the automatic steering mode by steering angle control. The steering mechanism 4 is provided downstream of the mode switching valve 8. The steering mechanism 4 includes a hydraulic cylinder 4A, a steering rack 2, a steering wheel (handle) 28, and an EPS valve 15, and hydraulic chambers 41 and 42 are provided in the hydraulic cylinder 4A, respectively. When hydraulic oil of a required hydraulic pressure is supplied to these hydraulic chambers 41, 42, a steering force acts on the rack 2 according to the hydraulic pressure of the hydraulic oil, and the steering mechanism 4 is a power steering mechanism, or It operates as an automatic steering mechanism.

Further, the hydraulic power source switching valve 27 and the steering angle control valve 7
A relief valve 13 as an automatic steering force control valve is interposed in an oil passage 29 between and. The hydraulic oil supplied to the hydraulic cylinder 4A when the automatic steering mode is set passes through the oil passage 29, and the hydraulic cylinder 4 is controlled by controlling the open / closed state of the relief valve 13.
The hydraulic pressure of the hydraulic oil flowing into A can be adjusted. In this embodiment, the steering angle control valve 7, the mode switching valve 8, the relief valve 13, and the hydraulic pressure source switching valve 27 are all solenoid valves.

The switching operation of these solenoid valves is controlled by the controller 1. In this controller 1, the steering force setting means 1A for automatic steering is set.
Then, the steering force for automatic steering is set, and the vehicle speed detecting means 1 is set.
The steering assist mode or the automatic steering mode is set on the basis of the information on the state of the vehicle and the road condition based on the detected information such as 9B. Further, the steering rack 2 includes a rack position detection sensor 2 for detecting displacement of the rack 2.
0 is provided, and the information from the rack position detection sensor 20 is also fed back to the controller 1.

In the steering assist mode, the hydraulic pressure source switching valve 27 is driven leftward in the drawing, and the mode switching valve 8 is driven rightward in the drawing, so that high-pressure hydraulic oil is supplied to the EPS valve 15. It is supposed to be done. Then, in the EPS valve 15, the amount of hydraulic oil to be supplied to the hydraulic cylinder 4A is set based on the control signal from the controller 1, the twist angle of the steering shaft 28A, etc., and the hydraulic oil from the EPS valve 15 is mode switched. Valve 8
To be sent to. In addition, the mode switching valve 8
Is controlled such that the hydraulic oil from the EPS valve 15 is directly supplied to the hydraulic cylinder 4A, a predetermined amount of hydraulic oil is supplied to the hydraulic chambers 41 and 42 of the hydraulic cylinder 4A, and the driver's steering The power is reduced.

During automatic steering, the hydraulic power source switching valve 27
Is driven rightward in the figure, and the mode switching valve 8 is driven leftward in the figure. As a result, the hydraulic oil is supplied to the oil passage 2
The steering angle control valve 7 is reached through 9. Then, the controller 1 mainly sets the control amount of the steering angle control valve 7 based on the information from the rack position detection sensor 20 to control the position of the steering rack 2.

By the way, as shown in FIG. 15, the controller 1 is provided with a drive circuit 24C. The drive circuit 24C converts the control command voltage set by the controller 1 into a current supplied to the solenoid 14 of the relief valve 13. In the relief valve 13, the open / close state is controlled by the current from the drive circuit 24C. It is like this.

Further, the drive circuit 24C is provided with a vehicle speed correspondence adjusting means 47, and in the automatic steering mode, the steering force set by the relief valve 13 is based on the information from the vehicle speed detecting means 19B. The steering force for automatic steering is adjusted so that it decreases as the vehicle speed increases. This vehicle speed correspondence adjusting means 47 is provided with an operating oil pressure characteristic map, and the automatic steering force in the automatic steering mode, that is, the oil pressure of the operating oil is, for example, as shown in FIG.
It is designed to be set based on the operating hydraulic pressure characteristic map as shown in FIG.

The characteristics of this map will now be described. Normally, the higher the vehicle speed, the greater the force required for steering, and the lower the speed, the greater the force required for steering. Therefore, in the present invention, as shown in the map of FIG. 16, the steering force during automatic steering is reduced as the vehicle speed increases. That is, in order for the driver to steer the steering wheel 28 against automatic steering control during automatic steering, a steering force that overcomes the hydraulic pressure of the hydraulic oil supplied to the hydraulic cylinder 4A is required.
This is because if the hydraulic pressure of the hydraulic oil is kept constant, the driver may be burdened with a large steering force against the hydraulic pressure.

Thus, in the vehicle speed correspondence adjusting means 47,
The control signal of the relief valve 13 is set so that the required hydraulic pressure is obtained based on the vehicle speed information input to the controller 1 and the fed-back hydraulic pressure information using the hydraulic pressure characteristic map. . Then, the automatic steering force is set to decrease as the vehicle speed increases, and the driver's steering becomes easier to overcome the automatic steering as the vehicle speed increases.
When driving at high speed, the vehicle is sufficiently responsive to artificial steering by the driver's intention.

Since the steering system with the automatic steering mechanism as the eighth embodiment of the present invention is configured as described above, the controller 1 can use the steering assist mode or the automatic steering mode based on the information from the sensor (not shown). Or set. When the steering assist mode is set, the pump 10
The hydraulic fluid discharged from the valve is guided to the EPS valve 15 via the flow dividing valve 12 and the hydraulic pressure source switching valve 27. Then, in the EPS valve 15, the amount of steering assist is set based on the control signal from the controller 1, the twist angle of the steering shaft 28A, and the like. And EPS
The hydraulic oil from the valve 15 is supplied to the hydraulic chambers 41 and 42 of the hydraulic cylinder 4A via the mode switching valve 8.

Further, when the automatic steering mode is set, the hydraulic oil discharged from the pump 10 is discharged from the flow dividing valve 12,
The steering angle control valve 7 is reached through the hydraulic pressure source switching valve 27 and the oil passage 29. The mode switching valve 8 is driven to the left side in the figure by the control signal of the controller 1. Then, the drive direction of the rack 2 is determined by the drive state of the steering angle control valve 7. That is, when the rudder angle control valve 7 is driven to the right in the figure, the hydraulic oil is transferred to the hydraulic cylinder 4A via the mode switching valve 8.
Is supplied to the hydraulic chamber 42 on the left side of the steering rack 2
Is driven to the left in the figure. On the contrary, when the steering angle control valve 7 is driven to the left, the hydraulic oil is supplied to the hydraulic chamber 41 on the right side of the hydraulic cylinder 4A to drive the steering rack 2 to the right in the figure. . Then, the steering direction of the vehicle is controlled by this.

In the automatic steering mode, the hydraulic pressure of the hydraulic oil is adjusted by the vehicle speed correspondence adjusting means 47 provided in the drive circuit 24C according to the vehicle speed. Specifically, the magnitude of the steering force at this time gradually decreases as the vehicle speed increases in accordance with the hydraulic pressure characteristic map shown in FIG. This reduces the burden of the steering force when the driver tries to steer against the automatic steering.

That is, in the vehicle speed correspondence adjusting means 47,
When the hydraulic pressure according to the vehicle speed is set, the open / closed state of the relief valve 13 is controlled so that the hydraulic pressure is obtained, and the hydraulic pressure for automatic steering is adjusted according to the open / closed state of the relief valve 13. The adjustment of the operating hydraulic pressure is performed, for example, when the vehicle speed becomes high, during the one control cycle, the relief valve 13
Is set to a long time, so that part of the hydraulic oil from the pump 10 is drained through the relief valve 13 and the hydraulic pressure supplied to the hydraulic cylinder 4A becomes low.

On the contrary, when the vehicle speed is low,
The relief valve 13 is driven to be closed for a long period of time during one control cycle, and relatively high-pressure hydraulic oil is supplied to the hydraulic cylinder 4A. As a result, steering can be reliably performed even at low speeds. Therefore, the above Examples 1 to 6
In addition to the effect in the present embodiment, in the present embodiment, the drive circuit 24C
Since the automatic steering force is set to be smaller as the vehicle speed increases according to the steering force characteristic map provided in the vehicle, the higher the vehicle speed, the easier the driver's steering is to overcome the automatic steering. When steering is performed in a direction different from the driver's intention at the time of steering, or due to an unforeseen situation, the driver is forced to apply a large steering force when the driver steers in a different direction from the automatic steering due to his judgment. The vehicle can be steered without control and the vehicle can be controlled sufficiently.

In this embodiment, the hydraulic oil of the automatic steering mechanism is shared with the 4WS and the automatic braking device, but the present invention is not limited to such a structure. Instead, for example, it may be combined with only 4WS or may be combined with only the automatic braking device.
Further, it may be combined with a hydraulic mechanism different from these, and further, it may not be combined with any other hydraulic mechanism.

Further, although the hydraulic circuit of this embodiment uses the oil pump 10 driven by the engine as a hydraulic pressure source, the constitution of the present invention is not limited to this, and is shown in FIGS. 5, 8 and 12. An electric hydraulic pump 23 as shown may be used.

[0121]

As described in detail above, according to the steering device with an automatic steering mechanism of the present invention as set forth in claim 1, the steering wheel is provided on the vehicle and is rotationally displaced by inputting an artificial steering force. And a steering input unit that is interposed between the steering wheel system and the steering wheel and that is displaced according to the rotational displacement of the steering wheel system, and has a steering angle that corresponds to the displacement of the steering input unit. A steering force transmission system that steers the steered wheels, and an automatic steering system that is provided in parallel with the steering wheel system and that includes a steering direction and a steering force required for the vehicle according to the traveling state and the traveling environment of the vehicle. And an automatic steering mechanism that includes automatic steering force setting means for setting a steering force, and applies the automatic steering force to the steering input section to thereby displace the steering input section to automatically steer the steered wheels. Provide The steering input section in the steering force transmission system is displaced according to the resultant force of the artificial steering force and the automatic steering force input to the steering input section to steer the steered wheels. Moreover, when the driver inputs a steering force to the steering wheel system with a force larger than the automatic steering force during automatic steering, the steering force of the driver can overcome the automatic steering force and steer the steered wheels. It is possible to prioritize steering according to the driver's intention.

According to the steering apparatus with automatic steering mechanism of the present invention as defined in claim 2, in addition to the structure of claim 1, steering is performed when the artificial steering force is input to the steering input section. The power steering mechanism includes a power steering mechanism that assists the steering force according to the state, and the automatic steering mechanism is configured to perform the automatic steering by applying the steering force for the automatic steering through the power steering mechanism. A configuration is provided in which a switching mechanism is provided to selectively switch between a steering assist operation state that operates in accordance with the artificial steering force and an automatic steering operation state that operates in accordance with the automatic steering mechanism. Thus, by controlling the switching mechanism, both automatic steering and artificial steering can be achieved. Further, since the power steering mechanism of the related art can be used, it is possible to suppress an increase in cost and an increase in weight as much as possible.

According to the steering apparatus with automatic steering mechanism of the present invention as set forth in claim 3, in addition to the configuration of claim 2, the magnitude of the artificial steering force input to the steering input section is increased. The steering wheel from the artificial steering force detecting means for detecting the height and direction, the steering input information detected by the artificial steering force detecting means, and the automatic steering information set by the automatic steering force setting means. A control means for controlling the switching mechanism so as to switch the power steering mechanism from the steering assist operating state to the automatic steering operating state when it can be determined that the required amount has not been steered in the direction to be steered. With the configuration described above, the steered wheels are steered by the automatic steering even when the proper steering is not performed due to the driver's carelessness and the like, and control such as danger avoidance can be performed.

According to the steering device with an automatic steering mechanism of the present invention as defined in claim 4, in addition to the configuration according to any one of claims 1 to 3, the artificial input to the steering input section is performed. The artificial steering force detecting means for detecting the magnitude and direction of the effective steering force is provided, and the automatic steering force setting means is provided with the artificial steering force detecting means during the operation of the automatic steering mechanism. Based on the detected steering input information, steering force reducing means for reducing the steering force for automatic steering when the artificial steering force is continuously applied for a predetermined time so as to oppose the steering of the automatic steering. With the configuration provided, if an artificial steering force is input for a predetermined time or more during automatic steering,
The steering force by the automatic steering mechanism is reduced, and the steering can be performed without requiring too much force.

According to the steering device with an automatic steering mechanism of the present invention as defined in claim 5, in addition to the configuration according to any one of claims 1 to 3, the artificial input to the steering input section is performed. Artificial steering force detecting means for detecting the magnitude and direction of the effective steering force is provided, and the automatic steering steering force setting means is provided by the automatic steering mechanism during the operation of the automatic steering mechanism. Based on the opposing force between the steering force for automatic steering and the artificial steering force detected by the artificial steering force detecting means, the greater the opposing force, the smaller the steering force for automatic steering, and the opposing force. With a configuration in which the steering force is set corresponding to the confronting force so that the steering force for automatic steering increases as the steering angle becomes smaller, the steering operation is more likely to overcome the automatic steering, and the steering intention by the driver can be prioritized. it can. As a result, when steering is carried out in a direction different from the driver's intention during automatic steering, or due to an unforeseen situation, when the driver makes a quick steering in a direction different from automatic steering due to the driver's judgment, the driver will experience a large steering force. It is possible to steer without being constrained and to control the vehicle sufficiently.

According to the steering device with an automatic steering mechanism of the present invention as defined in claim 6, in addition to the structure of any one of claims 3 to 5, the artificial steering force detecting means includes: A torque sensor that is interposed between a steering wheel and the steering force transmission system and that detects a torsion torque corresponding to the magnitude of the artificial steering force input to the steering input unit is used. As a result, this can be used from the power steering mechanism, and the cost can be reduced.

According to the steering apparatus with an automatic steering mechanism of the present invention as defined in claim 7, in addition to the structure of any one of claims 1 to 6, a vehicle speed detecting means for detecting the vehicle speed of the vehicle. Is provided, and during the operation of the automatic steering mechanism, based on the vehicle speed information detected by the vehicle speed detecting means,
With the configuration that the vehicle speed corresponding adjustment means for adjusting the steering force for automatic steering is provided so that the steering force applied by the steering force setting means for automatic steering becomes smaller as the vehicle speed increases,
The steering operation is easier to overcome the automatic steering, and the driver's intention can be prioritized. As a result, when steering is carried out in a direction different from the driver's intention during automatic steering, or due to an unforeseen situation, when the driver makes a quick steering in a direction different from automatic steering due to the driver's judgment, the driver will experience a large steering force. It is possible to steer without being constrained and to control the vehicle sufficiently.

Further, according to the steering apparatus with an automatic steering mechanism of the present invention as defined in claim 8, in addition to the structure according to any one of claims 1 to 7, the automatic steering mechanism is provided with an automatic steering mechanism. With the configuration in which the automatic steering force level setting means for artificially setting the level of the automatic steering force set by the steering force setting means is provided, the automatic steering force can be set to the driver's preference during automatic steering. It can be set accordingly.

As a result, even a driver having a weak force can steer the steering wheel against the automatic steering mechanism, and manual steering can be performed quickly and easily by the driver's intention even during automatic steering. You can

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram schematically showing a hydraulic system of a steering device with an automatic steering mechanism as a first embodiment of the present invention.

FIG. 2 is a block diagram schematically showing a configuration of a control system of the automatic steering mechanism in the steering apparatus with the automatic steering mechanism as the first embodiment of the present invention.

FIG. 3 is a flow chart for explaining the operation of the steering apparatus with the automatic steering mechanism as the first embodiment of the present invention.

FIG. 4 is a map for explaining the operation of the steering device with the automatic steering mechanism as the first embodiment of the present invention.

FIG. 5 is a hydraulic circuit diagram schematically showing a hydraulic system of a steering device with an automatic steering mechanism as a second embodiment of the present invention.

FIG. 6 is a hydraulic circuit diagram schematically showing a hydraulic system of a steering device with an automatic steering mechanism as a third embodiment of the present invention.

FIG. 7 is a flow chart for explaining the operation of the steering apparatus with the automatic steering mechanism as the third embodiment of the present invention.

FIG. 8 is a map for explaining the operation of a steering device with an automatic steering mechanism as a third embodiment of the present invention.

FIG. 9 is a hydraulic circuit diagram schematically showing a hydraulic system of a steering device with an automatic steering mechanism as a fourth embodiment of the present invention.

FIG. 10 is a hydraulic circuit diagram schematically showing a hydraulic system of a steering device with an automatic steering mechanism as a fifth embodiment of the invention.

FIG. 11 is a map for explaining the operation of a steering device with an automatic steering mechanism as a fifth embodiment of the present invention.

FIG. 12 is a hydraulic circuit diagram schematically showing a hydraulic system of a steering device with an automatic steering mechanism as a sixth embodiment of the present invention.

FIG. 13 is a schematic configuration diagram showing the functional configuration of a steering device with an automatic steering mechanism as a seventh embodiment of the present invention.

FIG. 14 is a graph showing a characteristic of an automatic steering force of a steering device with an automatic steering mechanism as a seventh embodiment of the present invention.

FIG. 15 is a hydraulic circuit diagram schematically showing a hydraulic system of a steering device with an automatic steering mechanism as an eighth embodiment of the present invention.

FIG. 16 is a graph showing an automatic steering pressure characteristic of a steering device with an automatic steering mechanism as an eighth embodiment of the present invention.

[Explanation of symbols]

1 Controller as control means 1A, 46 Steering force setting means for automatic steering 2 Rack as steering input section 3 Steering force transmission system 4 Power steering mechanism 4A Hydraulic cylinder 5 Automatic steering mechanism 5B Feedback section 7 Steering angle control valve (automatic steering Control valve) 8 Mode switching valve as switching mechanism 9 Engine 10 Oil pump 11 Oil tank 12 Dividing valve 13 Relief valve 14 Solenoid valve 15 EPS valve 16 Return spring 17 ECU 18 Automatic steering determination means 18A CCD camera 18B Laser radar 18C Image processing Part 18D Information control part 18E Vehicle distance determination part 18F Threshold value storage means 18G Voice guidance means 18H Display 19 Sensor group 19A Torque sensor as artificial steering force detection means 19B Car Vehicle speed sensor 20 as speed detecting means 20 Rack position detecting sensor 22 Electric motor 23 Electric hydraulic pump 24, 24A-24C Drive circuit as steering force reducing means 26 Steering force level setting means 27 Hydraulic source switching valve 28 Handle 28A Steering shaft 29 Oil Road 31 Steering wheel angle sensor 32 Steering wheel angle gain setting means 33 Torsion bar 34 Gain changeover switch as steering force level setting means for automatic steering 35 Amplifier 36 Steering wheel system 41, 42 Hydraulic chamber 47 Vehicle speed corresponding adjustment means

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takahiro Maemura 5-3-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Tadao Tanaka 5-33-8 Shiba, Minato-ku, Tokyo Within Mitsubishi Motors Corporation

Claims (8)

[Claims] 1. A steering wheel system provided in a vehicle, which is rotationally displaced by inputting an artificial steering force, and a rotation of the steering wheel system, which is interposed between the steering wheel system and a steering wheel. A steering force transmission system for steering the steered wheels at a steering angle according to the displacement of the steering input unit; and a steering force transmission system that is arranged in parallel with the steering wheel system. An automatic steering steering force setting means for setting a steering force for automatic steering composed of a steering direction and a steering force required for the vehicle according to a traveling state and a traveling environment of the vehicle is provided, and the steering force for automatic steering is input to the steering input. An automatic steering mechanism that applies a displacement to the steering input section to automatically steer the steered wheels by adding the steering input section to the steering input section of the steering force transmission system. Exercises A steering device with an automatic steering mechanism, which is configured to be displaced according to a resultant force of a steering force and a steering force for automatic steering to steer the steered wheels. 2. The steering input section includes a power steering mechanism for assisting the steering force according to the steering state when the artificial steering force is input, and the automatic steering mechanism is for automatic steering through the power steering mechanism. The power steering mechanism is configured to perform automatic steering by applying a steering force, and the power steering mechanism is operated according to the artificial steering force for steering assist and the automatic steering mechanism. The steering apparatus with an automatic steering mechanism according to claim 1, further comprising a switching mechanism that selectively switches between one of the operating states for automatic steering. 3. An artificial steering force detecting means for detecting the magnitude and direction of the artificial steering force input to the steering input section, and steering input information detected by the artificial steering force detecting means. When it is determined from the automatic steering information set by the steering force setting means for automatic steering that the necessary amount of steering has not been performed in the direction in which the steered wheels should be steered, the power steering mechanism is operated for the steering assist operation. The steering device with an automatic steering mechanism according to claim 2, further comprising: a control unit that controls the switching mechanism so as to switch from a state to the operating state for automatic steering. 4. An artificial steering force detecting means for detecting the magnitude and direction of the artificial steering force input to the steering input section is provided, and the automatic steering force setting means includes the automatic steering force setting means. During the operation of the steering mechanism, based on the steering input information detected by the artificial steering force detecting means, the artificial steering force is continuously applied for a predetermined time so as to oppose the steering of the automatic steering. The steering force reducing means for reducing the steering force for automatic steering is provided in the.
A steering device with an automatic steering mechanism according to any one of 3 to 3. 5. An artificial steering force detection means for detecting the magnitude and direction of the artificial steering force input to the steering input section is provided, and the automatic steering force setting means is provided for the automatic steering. During the operation of the steering mechanism, based on the opposing force between the automatic steering force provided by the automatic steering mechanism and the artificial steering force detected by the artificial steering force detection means,
The steering force is set corresponding to the opposing force so that the steering force for automatic steering decreases as the opposing force increases and the steering force for automatic steering increases as the opposing force decreases. The steering apparatus with an automatic steering mechanism according to any one of claims 1 to 3, characterized in that: 6. The artificial steering force detection means is interposed between the steering wheel and the steering force transmission system, and corresponds to the magnitude of the artificial steering force input to the steering input section. The steering device with an automatic steering mechanism according to any one of claims 3 to 5, characterized in that a torque sensor for detecting the twisted torque is used. 7. A vehicle speed detecting means for detecting a vehicle speed of the vehicle is provided, and the steering force setting for automatic steering is set based on vehicle speed information detected by the vehicle speed detecting means during operation of the automatic steering mechanism. 7. A vehicle speed correspondence adjusting means for adjusting the steering force for automatic steering so that the steering force applied by the means becomes smaller as the vehicle speed increases. 7. Steering device with automatic steering mechanism. 8. The automatic steering mechanism is provided with an automatic steering steering force level setting means capable of artificially setting the level of the automatic steering steering force set by the automatic steering steering force setting means. The steering apparatus with an automatic steering mechanism according to any one of claims 1 to 7, characterized in that: