JP2586702B2 - Automatic steering system for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

According to the present invention, the input shaft of the steering mechanism is rotated by the automatic steering drive mechanism under the control of the automatic steering control means,
The present invention relates to a vehicle automatic steering device that automatically steers a vehicle.

[Prior art]

Conventionally, an apparatus disclosed in Japanese Utility Model Laid-Open No. 60-115174 is known as this type of apparatus. According to this device, the rotation shaft of the servomotor connected to the controller for automatic steering and the steering shaft are connected via the transmission mechanism composed of gears.

[Problems to be solved by the invention]

However, in the above-described conventional apparatus, in order to allow the driver to manually operate the steering wheel for some reason in the mobile steering control state, the operation switch of the automatic steering apparatus is switched to stop the operation of the automatic steering apparatus. The steering wheel had to be operated or the steering wheel had to be overcome by overcoming the servo motor in the automatic steering device. SUMMARY OF THE INVENTION The present invention has been made in order to address the above-described problems, and has an automatic steering apparatus for a vehicle capable of extremely easily disconnecting an automatic steering control system when it is desired to switch from automatic steering to manual steering operation. The purpose is to provide.

[Means for Solving the Problems]

In order to achieve the above object, a structural feature of the present invention is that a hydraulic pump (21) that operates in response to a rotational steering input input to an input shaft (18g) connected to a handle (14).
The hydraulic oil discharged from the steering link mechanism (11,15a-17a, 15
b to 17b), a power steering mechanism (18a) that controls the supply and discharge of a power cylinder (22) provided in
18g) and a drive mechanism for automatic steering which is connected to the input shaft of the power steering mechanism via the transmission mechanism and rotates the input shaft by a required amount under the control of the automatic steering control means (24). (30), the transmission mechanism is connected to the automatic steering drive mechanism so as to always transmit power, and the first and second transmission shafts are connected to the input shaft along the axial direction thereof.
A sliding member (31) slidably mounted between predetermined positions of the input shaft; a spring (34) for urging the sliding member toward the first predetermined position along the axial direction of the input shaft; A displacement mechanism (26, 35a, 35b, which displaces the sliding member to a second predetermined position along the axis of the input shaft against the urging force of the spring in response to an operation for selecting automatic steering. 36a, 36b)
When the sliding member is at the second predetermined position, the sliding member is held at the second predetermined position, and the sliding member and the input shaft are connected so that power can be transmitted. When the reaction force of a predetermined value or more acts between the sliding member and the input shaft by the turning operation of the handle in the state where the sliding member is held at the position, the holding of the sliding member at the second predetermined position is released, and the sliding is performed. When the moving member is at a position other than the second predetermined position, the holding mechanism (18i1, 18i2, 18j,
31a).

Effect of the Invention

In the present invention configured as described above, when the operation for selecting automatic steering is performed when the sliding member is biased by the spring and is at the first predetermined position, the displacement mechanism is moved to the sliding member. Is displaced along the axial direction of the input shaft to a second predetermined position against the urging force of the spring.
Since the holding mechanism holds the sliding member at the second predetermined position and connects the sliding member and the input shaft so that power can be transmitted, the driving force of the automatic steering drive mechanism is transmitted to the input shaft, The vehicle is automatically steered. On the other hand, in this state, when the handle is rotated and a reaction force of a predetermined value or more acts between the sliding member and the input shaft, the holding mechanism releases the holding of the sliding member at the second predetermined position. . Therefore, the holding mechanism is urged by the spring and displaced to the first predetermined position to disable power transmission between the sliding member and the input shaft, so that the automatic steering by the automatic steering drive mechanism is released. Then, the vehicle enters a manual steering state in which the vehicle is steered by turning the steering wheel. In this state, if the automatic steering is selected as described above, the sliding member is displaced to the second predetermined position, and the vehicle is returned to the automatic steering state.

【The invention's effect】

As described above, in the present invention, when the driver turns the steering wheel in the automatic steering state, the power transmission connection between the automatic steering drive mechanism and the input shaft of the power steering mechanism is released, and thereafter, In this case, the automatic steering control system is disconnected and the driver can perform a manual steering operation. In addition, even after the automatic steering control system is disconnected, the automatic steering drive mechanism and the input shaft of the power steering mechanism can be connected so that power can be transmitted again by the displacement mechanism, and manual steering can be performed. Even after switching to the state, the automatic steering state can be arbitrarily returned.

【Example】

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 2 schematically shows an entire front wheel steering mechanism in which the vehicle automatic steering device according to the present invention is applied to a vehicle having a front wheel steering mechanism. The front wheel steering mechanism is displaced in the axial direction and the left and right front wheels FW1, FW
It has a rack bar 11 that steers 2. The rack bar 11 is connected to a steering wheel 14 via a pinion gear 12, a lower steering shaft 13a, and an upper steering shaft 13b, and left and right tie rods swingably connected to rack ends 15a, 15b fixed to both ends thereof. Left and right front wheels FW1 and FW2 are connected via left and right knuckle arms 17a and 17b rotatably connected to the tie rods 16a and 16b. A control valve 18 composed of a four-way valve shown in an enlarged manner in FIG. 1 is mounted between the lower steering shaft 13a and the upper steering shaft 13b. The control valve 18 includes an outer sleeve 18f, an inner spool 18g, and a torsion bar 13b3 formed at a lower end of the upper steering shaft 13b in a case 18e also serving as a gear box.
And the upper end of the torsion bar 13b3 and the upper end of the inner spool 18g are connected non-rotatably, and the lower end of the torsion bar 13b3 and the outer sleeve are connected.
The lower end of 18f is connected to the lower steering shaft 13a so as not to rotate, and is supplied from the hydraulic pump 21 via the conduit P1 and the port 18a according to the rotation angle deviation between the inner spool 18g and the outer sleeve 18f. Port 18b (or port 18
c) from the right oil chamber 22a of the power cylinder 22 (or the left oil chamber 22).
b), hydraulic oil from the left oil chamber 22b (or the right oil chamber 22a) of the cylinder 22 is introduced from the port 18c (or the port 18b), and is supplied from the port 18d to the reservoir 23 through the conduits P2 and P5. Discharge to When the inner spool 18g rotates in the direction of the solid line arrow in FIG. 1 and the relative angle with the outer sleeve 18f shifts, the ports 18a and 18b communicate with each other, and the ports 18d and 18c communicate with each other. When the inner spool 18g rotates in the direction opposite to the direction of the solid arrow in FIG. 1 and the relative angle with the outer sleeve 18f is shifted, the port 18a and the port 18
c and the port 18d and the port 18b. The upper end of the inner spool 18g is arranged concentrically with the outer shaft 13b6 and the torsion bar 13b3. Immovably connected, inner spool 18g and outer shaft 13b6
Are non-rotatably connected by pins 18i1 and 18i2. The pins 18i1, 18i2 are provided with holes 13b2, 13b7, 18g2 linearly provided in the torsion bar 13b3, the outer shaft 13b6, and the inner spool 18g as shown in an enlarged manner in FIG.
13b2, 13b7, 18
It is urged outward in the circumferential direction by a spring 18j disposed in g2. In FIGS. 3 and 1, the right part shows the arrangement state of each member in the automatic steering state, and the left part shows the manual line state. On the side where the spring 18j urges the pins 18i1 and 18i2, a cylindrical piston sleeve 31 to which the rotation of the motor 30 is transmitted is slidably in contact with the inner spool 18g and the outer periphery of the outer shaft 13b6 and is slidable in the axial direction. The piston sleeve 3 is arranged concentrically, and the rotating shaft 30a of the motor 30
A drive gear 32 fixed to the piston sleeve 31 by a screw 33a and a driven gear 33 fixed to the upper end of the piston sleeve 31 by a screw 32a.
And is connected to the motor 30 via The servo motor 30 is fixed to the control valve 18 in the outer case, and rotates the piston sleeve 31 forward and backward by a predetermined amount via gears 32 and 33 in accordance with a control signal output from the automatic steering control unit 24. Rotate in the direction. For example, servo motor 30
Is forward (or reverse) in the direction of the dashed arrow shown in FIG. 1, the piston sleeve 31 is moved through the drive gear 32 and the driven gear 33 in the direction of the solid line arrow (or the direction opposite to the direction of the solid line arrow) in FIG. The control valve 18
Is rotated in the direction of the arrow shown in FIG. 2 (or in the direction opposite to the direction of the arrow). Therefore, the pinion 12 is rotated in the same direction via the power steering mechanism, and the front wheels FW1 and FW2 are steered rightward (or leftward) via the rack 11. Here, the automatic steering control unit 24 outputs a control signal to the servomotor 30 according to a predetermined control mode, and performs steering control according to a predetermined program or tracks a vehicle ahead. The steering control is performed in accordance with an instruction of a signal generator installed on the road surface. Further, the piston sleeve 31 is urged downward in the axial direction by a spring 34, and the lower end of the piston sleeve 31 forms a holding mechanism together with the pins 18i1 and 18i2 at the cross section as shown in FIG. 4 and FIG. A plurality of recesses 31a are formed. The portion where the concave portion 31a is formed is formed in a flange shape, and the upper oil chamber 35a and the lower oil chamber 35b are formed above and below the piston sleeve 31 by the flange portion and the outer oil seal 31b.
And form. A transmission mechanism is constituted by the entire rotation drive path from the rotation shaft 30a of the motor 30 to the inner spool 18g via the gears 32 and 33, the piston sleeve 31, and the holding mechanism. A port 36a and a port 36b are connected to the upper oil chamber 35a and the lower oil chamber 35b, respectively, and the ports 36a and 36b are connected to the control valve 26 via conduits P3 and P4. This control valve 26
Are connected to the conduits P2 and P5 by energizing the solenoids 26a and 26b.
When the automatic steering control unit 24 energizes the solenoid 24a and closes the switch 24b, the power supplied from the battery is changed by operating the switch 25. The oil is supplied to the solenoids 26a and 26b to control the flow path of the hydraulic oil. That is, when the movable section 25a of the neutral return type switch 25 is set to the fixed section 25b side for instructing automatic steering, current flows through the solenoid 26b, and the control valve 26 moves to the left in the figure and is discharged from the port 18d. Hydraulic oil supplied to the control vibrator 26 via the conduit P2 is supplied to the lower oil chamber 35b from the port 86b via the conduit P4 to move the piston sleeve 31 upward against the spring 34 and to move the upper oil chamber 35a The hydraulic oil in the reservoir 23 is supplied from port 36a through conduits P3 and P5.
To drain. When the movable section 25a of the switch 25 is set to the fixed section 25c for instructing manual steering, current flows through the solenoid 26a, and the control valve 26 moves rightward in the drawing, is discharged from the port 18d, and is discharged through the conduit P2. The hydraulic oil supplied to the control valve 26 is supplied to the port 36a via the conduit P3.
The oil is supplied to the upper oil chamber 35a to move the piston sleeve 31 downward, and the hydraulic oil in the lower oil lower 35b is supplied to the port 36b.
The fluid is discharged to the reservoir 23 through the conduits P4 and P5. Note that when no current flows through any of the solenoids 26a and 26b, the conduits P2 and P5 are in communication. The power cylinder 22 to which hydraulic oil is supplied and discharged by the control valve 18 drives the rack bar 11 in the axial direction in accordance with the supply and discharge of the hydraulic oil, and the handle 14 or the automatic steering control unit 24 by the driver. Assists the steering of the left and right front wheels FW1 and FW2 by the servo motor 30 controlled by the controller. Next, the operation of the above embodiment will be described. After turning on the ignition key (not shown) and starting the engine, when the driver tilts the switch 25 toward the fixed section 25b indicating automatic steering, current flows through the solenoid 26b, and the control valve 26 moves leftward in the figure. I do. Then, hydraulic oil is supplied to the lower oil chamber 35b among the oil chambers formed above and below the piston sleeve 31, and the piston sleeve 31 moves upward. Thereafter, when the switch 25 is released, the switch 25 returns to the neutral position, no current flows through the solenoid 26b, the control valve 26 also returns to the neutral position, and no hydraulic oil is supplied to the lower oil chamber 35b. The piston sleeve 31 is urged downward by the spring 34, but when the piston sleeve 31 moves upward, the pins 18i1 and 18i2 enter into the recesses 31a provided in the piston sleeve 31, and the holding mechanism by the two. As a result, the piston sleeve 31 stops at the position shown on the right side of FIG. In this state, it is assumed that the automatic steering control unit 24 determines that it is necessary to turn to the right according to a predetermined control mode. Then, the automatic steering control unit 24 outputs a control signal to the servo motor 30 to perform normal rotation. When the servo motor 30 rotates forward, the piston sleeve 31 is rotated via the drive gear 32 and the driven gear 33 in the direction indicated by the solid line arrow in FIG. When the piston sleeve 31 rotates, the position of the recess 31a provided on the inner wall of the sleeve also rotates, so that the tips of the pins 18i1 and 18i2 urged by the spring 18j in the recess 31a rotate in the same direction. Pin 18i1,1 with the force to be forced
A force acts to push 8i2 toward the center of the rotation axis. However, since the force provided by the spring 18j is strong, the pins 18i1,1
8i2 does not move in the direction of the center of the rotation axis, so when the position of the recess 31a provided on the inner wall of the piston sleeve 31 rotates, the pins 18i1 and 18i2 also rotate. Pins 18i1, 18
With the rotation of i2, the upper end of the inner spool 18g into which the pins 18i1 and 18i2 are inserted also rotates in the direction of the solid line arrow in FIG. 1, so that the relative angle between the inner spool 18g and the outer sleeve 18f changes. As a result, the port 18a communicates with the port 18b, and the port 18d communicates with the port 18c. Accordingly, since the high-pressure hydraulic oil supplied from the hydraulic pump 21 is supplied from the port 18a to the right oil chamber 22a of the power cylinder 22 through the port 18b, the piston 22c in the power cylinder 22 is moved leftward in FIG. The low-pressure hydraulic oil in the left oil chamber 22b of the power cylinder 22 is discharged from the port 18c to the reservoir 23 via the port 18d. When the piston 22c in the power cylinder 22 moves to the left, the left and right front wheels move through the tie rods 16a and 16b and the knuckle arms 17a and 17b.
Since FW1 and FW2 are steered to the right, steering by the servo motor 30 is assisted by the hydraulic mechanism. The pinion 1 is rotated in the same direction as the inner spool 18g in FIG. 1 with the movement of the power cylinder 22. Since the lower steering shaft 13a fixed to the pinion 12 also rotates by the rotation of the pinion 12, the outer sleeve 18f connected to the lower steering shaft 13a also rotates by a predetermined amount, and the rotation of the outer sleeve 18f is reduced. Inner spool 18g
Until catching up with the rotation (until the relative angle difference disappears), the hydraulic mechanism assists in turning. On the other hand, it is assumed that the automatic steering control unit 24 determines that it is necessary to steer to the left according to a predetermined control mode. The automatic steering control unit 24 outputs a control signal to the servo motor 30 to rotate the piston sleeve 31 in the direction opposite to the direction of the solid arrow in FIG. When the piston sleeve 31 rotates in the direction opposite to the direction indicated by the solid arrow in FIG. 1, the upper end of the inner spool 18g rotates in the direction opposite to the direction indicated by the solid arrow shown in FIG. 1 via the pins 18i1 and 18i2. The port 18c communicates, and the port 18d communicates with the port 18b. Accordingly, since the high-pressure hydraulic oil supplied from the hydraulic pump 21 is supplied from the port 18a to the left oil chamber 22b of the power cylinder 22 through the port 18c, the piston 22c in the power cylinder 22 is moved rightward in FIG. The low-pressure hydraulic oil in the right oil chamber 22a of the power cylinder 22 is discharged from the port 18b to the reservoir 23 via the port 18d. When the piston 22c in the power cylinder 22 moves to the right, the left and right front wheels move through the tie rods 16a and 16b and the knuckle arms 17a and 17b.
Since FW1 and FW2 are steered to the left, the steering by the servo motor 30 is assisted by the hydraulic mechanism until the rotation of the outer sleeve 18f catches up with the rotation of the inner spool 18g in this case as well. On the other hand, if the driver tilts the switch 25 toward the fixed section 25c indicating manual steering while the vehicle is stopped or traveling straight, current flows through the solenoid 26c and the control valve 26 moves rightward in the figure. . Then, hydraulic oil is supplied to the upper oil chamber 35a among the oil chambers formed above and below the piston sleeve 31, and a force for pushing the piston sleeve 31 downward is urged. In the case of automatic steering, when the piston sleeve 31 is pushed up, the pins 18i1 and 18i2
1a, the spring 34 held the piston sleeve 31 at the same position against the force of pushing down the piston sleeve 31 by the holding mechanism including the pin and the recess. However, when the operating oil is supplied to the upper oil chamber 35a, the force for pushing down the piston sleeve 31 becomes stronger, and therefore the tip of the pins 18i1 and 18i2 forming the holding mechanism is positioned at the center of the rotation shaft from the upper wall surface of the recess 31a. The pin 18i1 and 18i2 move to the center of the rotation axis, and the piston sleeve 3
1 moves downward as shown on the left side of FIG. Thereafter, when the switch 25 is released, the switch 25 returns to the neutral position, the current stops flowing to the solenoid 26c, the control valve 26 returns to the neutral position, and the hydraulic oil is not supplied to the upper oil chamber 35a. Since the inner peripheral surface of the piston sleeve 31 is cylindrical except for the recess 31a at the lower end, when the piston sleeve 31 moves downward, the tips of the pins 18i1 and 18i2 come into rolling contact with the cylindrical inner peripheral surface. And the coefficient of friction becomes extremely small. Therefore, even if the automatic steering control unit 24 rotates the servomotor 30 forward or backward to rotate the piston sleeve 31, the rotation of the piston sleeve 31 is not affected by the pins 18i1 and 18i.
It is not transmitted to 2, and the piston sleeve 31 idles. In this state, when the driver turns the steering wheel 14 to perform steering, the rotation is transmitted from the upper steering shaft 13b to the upper end of the torsion bar 13b3, and furthermore, the upper steering shaft is rotated by the pin 13b5.
13b Outer shaft 13b6 synchronized with upper end in rotation direction
And the inner spool 18g is rotated via the pins 18i1 and 18i2. Due to the rotation of the inner spool 18g, a relative angle difference is generated between the inner spool 18g and the outer spool 18f, and steering is assisted by the hydraulic oil as in the case of automatic steering. On the other hand, when the driver operates the switch 25, the piston sleeve 31 moves up and down, and in each case, the piston sleeve 31 is moved by the servomotor 30 via the holding mechanism.
Although it is determined whether or not the rotation of 31 is transmitted to the inner spool 18g, it is troublesome to manually switch to manual steering when an abnormality occurs in the automatic steering control system. For this reason, in this embodiment, even in the state of automatic steering, the operation is performed as follows, and the manual operation can be automatically performed. In the automatic steering state, as described above, hydraulic oil is supplied to the lower oil chamber 35b, and the piston sleeve 31 moves upward,
The piston sleeve 31 is maintained at the same position even after the engagement of the recesses 31a of the piston sleeve 31 with the recesses 18a, 18i2 causes the supply of hydraulic oil to stop. In this state, the tips of the pins 18i1 and 18i2 have entered the recesses 31a as shown in FIG.
As a result, when the piston sleeve 31 rotates, the pins 18i1 and 18i2 rotate together with the recess 31a. However, it is assumed that some abnormality occurs in the automatic steering control unit 24 during the movement steering, or that the driver needs to perform manual steering even if no abnormality occurs. If it is determined by the automatic steering control unit 24 that it is not necessary to steer the front wheels FW1 and FW2, the servomotor 30 stops and maintains the stopped state, and the piston sleeve
31 is also stopped at the same position. At this time, if the driver rotates the steering wheel 14, the pin 1 is moved from the upper steering shaft 13b to which the steering wheel 14 is connected.
The same rotation is transmitted to pins 18i1 and 18i2 via 3b5 and outer shaft 13b6. As a result, the pins 18i1 and 18i2 try to start rotational movement, but since the piston sleeve 31 with which the tips of the pins 18i1 and 18i2 are engaged is stopped,
A force is applied to the tip ends of the pins 18i1 and 18i2 from the side wall surface of the recess 31a in the piston sleeve 31 toward the center of the rotation axis. When the handle 14 is further rotated, this force causes the pins 18i1 and 18i2 to move toward the center of the rotation shaft against the spring 18j, and the contact area between the wall surface of the recess 31a and the pins 1i1 and 18i2 gradually decreases. Come. As shown in FIG. 5, when the tips of the pins 18i1 and 18i2 reach between the recesses 31, the force of the tips of the pins 18i1 and 18i2 supporting the piston sleeve 31 generally weakens, and the piston sleeve 31 34
Is moved downward. As a result, it will be in the same state as in manual steering,
Thereafter, even if the piston sleeve 31 is rotated by the movement steering control unit 24, the rotation is not transmitted to the input shaft of the control valve 18. That is, the driver rotates the steering wheel 14 during the automatic steering to cause a predetermined or more reaction force between the piston sleeve 31 which is the transmission mechanism in the automatic steering control system and the inner spool 18g which is the input shaft of the power steering mechanism. As a result, the power transmission between the piston sleeve 31 and the inner spool 18g is released, and the manual steering is switched. On the other hand, after switching to manual driving as described above during automatic steering, to switch from manual steering to automatic steering again, the switch 25 may be tilted to the fixed intercept 25b indicating automatic steering.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an automatic steering device for a vehicle according to the present invention, FIG. 2 is a schematic configuration diagram of a front wheel steering mechanism to which the automatic steering device for a vehicle according to the present invention is applied, and FIG. 4 and 5 are enlarged cross-sectional views showing the operation state of the holding mechanism. Description of reference numerals 11 ... rack bar, 12 ... pinion, 13a, 13b ... steering shaft, 14 ... handle, 16a, 16b ... tie rod, 17a, 17b
…… Knuckle arm, 18g …… Inner spool, 18f ……
Outer sleeve, 18i1, 18i2 ... Pin, 21 ... Hydraulic pump, 22 ... Power cylinder, 24 ... Automatic steering controller, 25
... switch, 26 ... control valve, 30 ... servo motor, 31 ... piston sleeve, 31a ... recess, 34 ... spring.

Claims (1)

(57) [Claims] 1. A hydraulic cylinder, which operates in response to a rotational steering input inputted to an input shaft connected to a steering wheel, controls supply and discharge of pressure oil discharged from a hydraulic pump to a power cylinder provided in a steering link mechanism. A power steering mechanism for driving the steering link mechanism by means of the power steering mechanism, and a required amount of the input shaft connected to an input shaft of the power steering mechanism via a transmission mechanism under the control of the automatic steering control means. An automatic steering device for a vehicle, comprising: an automatic steering drive mechanism for rotating the vehicle; wherein the transmission mechanism is always connected to the automatic steering drive mechanism so as to be able to transmit power, and is connected to the input shaft in an axial direction thereof. A sliding member slidably mounted between first and second predetermined positions along the first axis and the first axis along the axial direction of the input shaft.
A spring biasing the predetermined position of the sliding member in response to an operation for selecting automatic steering, the second sliding member sliding along the input-side axial direction against the biasing force of the spring against the biasing force of the spring. A displacement mechanism for displacing the sliding member to the second predetermined position, holding the sliding member at the second predetermined position when the sliding member is at the second predetermined position, and powering the sliding member and the input shaft. A reaction force greater than or equal to a predetermined value acts between the sliding member and the input shaft by rotating the handle while the sliding member is held at the second predetermined position. When the sliding member is released from holding at the second predetermined position, the power transmission between the sliding member and the input shaft is disabled when the sliding member is at a position other than the second predetermined position. And a holding mechanism having the following configuration. Automatic steering apparatus for a vehicle.