JPS62198565A - Neutral position restoring device for steering device - Google Patents

Abstract

PURPOSE:To make it easy to start a vehicle on a narrow road or the like, by restoring a steering system to a neutral position by a motor control means according to a detection signal from a position detecting means for detecting a steering position upon closing a switch. CONSTITUTION:A large-diameter toothed pulley 11a is integrally mounted on the outer periphery of a nut member 11. A motor 13 is provided on the upper side of rotation of the pulley 11a in parallel relationship to a shaft 8. A rotating shaft of the motor 13 is integrally formed with a small-diameter toothed pulley 14. A timing belt 15 is wrapped between the small-diameter pulley 14 and the large-diameter pulley 11a. When a switch 20 is closed, and then a signal from a neutral position detecting means 16 is inputted into a control device, a control means operates the motor 13 to restore a steering system to its neutral position.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a steering device that automatically returns the steering system to the intermediate position using the power of an electric motor when the steering system is desired to return to the intermediate position. This invention relates to an intermediate position return device.

(Prior Art) A steering device converts the rotation of the steering wheel into a rocking motion of the wheels to enable steering of the vehicle.While the vehicle is running, the rotation of the steering wheel causes the vehicle to be steered. It has a characteristic that the device itself tends to return to the intermediate position by means of caster trails and the like. Therefore, generally, when the steering wheel is released or the steering force is weakened, the steering wheel (steering system) is returned to the intermediate position.

(Problem to be Solved by the Invention) However, in the conventional steering device described above, when the vehicle is stopped, there is no force to return the steering wheel to the middle position, so even when parking on a narrow road or in a bad garage environment, It may be difficult to park the vehicle in a garage, and it requires considerable driving experience to be able to park the vehicle in a straight line. Furthermore, even when the vehicle starts from a state where the steering wheel has not been returned to the middle position, it may be difficult to start the vehicle smoothly due to narrow roads or poor vehicle/interference conditions.

(Object of the Invention) Therefore, the present invention provides a steering device that can smoothly stop and start even on narrow roads or in bad garages by automatically returning the steering device to the middle position when desired. The object of the present invention is to provide a position return device.

(Means for solving the problem and its operation) ゛The intermediate position return device of the present invention comprises a position detection means for detecting the steering position of the steering system, a switch means, and an electric motor control means for driving and controlling the electric motor. When the steering system is turned on, the electric motor is driven and controlled by the motor control means based on the detection signal from the position detection means to return the steering system to the intermediate position.

(Embodiment) A preferred embodiment of the present invention will be described below based on the accompanying drawings.

Fig. i1 is a perspective view of a steering device equipped with the intermediate position return device of this embodiment, Fig. 2 shows its control device, and Fig. 3 shows its control processing.

In Fig. 1, (1) is a steering wheel, and a first shaft (2), a second shaft (3), and a third shaft (4) are integrally fixed to this steering wheel (1). are connected by universal joints (5) and (8), and transmit the rotation of the steering wheel (1) to the third axis (0.
A pinion gear (7) is integrally provided at the end of the shaft (0) opposite to the universal joint (6), and this pinion gear (7)
and a rack (8) provided at one end of the fourth shaft (8), and the rotation of the steering wheel (1) is axially linked to the fourth wheel (8) via the pinion gear (7). is being converted to . On the other hand, a spiral groove (1o) is provided on the outer peripheral surface of the other end side of the fourth vehicle (8), and a nut member (
11) is ringed, and a plurality of poles (not shown) are interposed between these spiral grooves, and the fourth shaft (8) and the nut member (11) are engaged with each other by these poles. . That is, the spiral groove (10), the pole and the nut member (1
1) constitutes a pole screw (12). The fourth shaft (8) is supported in a case (not shown) so as to be movable in the axial direction, and the nut member (11) is supported in a rotatable but immovable manner in the axial direction. Further, a large-diameter toothed pulley (lla) is integrally provided on the outer periphery of the nut member (11), and above the rotation of this pulley (11a) is a t54 shaft (8
) An electric motor (13) is provided substantially parallel to the motor. A small-diameter toothed pulley (14) is attached to the rotating shaft of this electric motor (13).
) is integrally provided, and a timing bell l-(
15) is wound. Therefore electric &! The rotation of (13) is decelerated by the pulley ratio and transmitted to the nut member (11), which converts it into axial movement of the fourth shaft (8). Both ends of the fourth shaft (8) are connected to the steering wheel via tie rods and knuckles (not shown), and the axial movement of the fourth shaft (8) is converted into a rocking detour of the steering wheel. This makes it possible to steer the vehicle.

A plane part is formed on the side surface of the fourth shaft (8), and a middle position detection means (16) is provided on this plane part. The intermediate position detection means (!6) consists of a long thin plate-like resistor (17) fixed to the four PFJs (8), and a contact piece (18) that is set to the intermediate position at the beginning of this resistor (17). ), and this contact piece (1B) provides resistance (17) with its own spring force.
is in contact with. The contact piece (18) is insulated and fixed to a case (not shown), and is always in contact with a resistor (17) that moves in the axial direction together with the fourth shaft (8). Resistance (17
) and the contact piece (18) are connected to the control device (19), and in response to the axial displacement of the fourth axis (8), the contact piece (!8) and the end of the resistor (17) Since the resistance value changes, the position of the fourth axis (8)' is detected as a change in one resistance value. A switch (switch means) (20) is provided near the steering wheel (1) in the vehicle interior, that is, near the late seat.
consists of an on/off switch that is turned on by the driver's will, and this switch (20) and the electric motor 411 described above are connected to each other.
[(13) is connected to the control device (motor control means) (19).

In FIG. 2, one end of the resistor (17) of the intermediate position detecting means (IG) is connected to the constant voltage circuit (4) via the resistor (21).
2), and the other end is connected to the common side (earth) via a resistor (22). Contact piece (18
) is input to a low-pass filter circuit (23), and this circuit (23) removes noise caused by movement of the contact portion between the contact piece (18) and the resistor (17). The output of the low-pass filter (23) is connected to the operational amplifier (2) via a resistor (24).
5) is connected to the inverting terminal. Operational amplifier (25)
The voltage of the power supply (A) is connected to the non-inverting terminal of the resistor (26) and (
27) and is inputted through a resistor (28), and the divided voltage is directly inputted to an A/D converter (29) and becomes a reference voltage. Operational amplifier (
A negative feedback circuit is formed by a resistor (30) connected between the inverting terminal of the operational amplifier (25) and the output terminal of the operational amplifier (25), and an output resistor (31) is connected to the output of the operational amplifier (25). A/D converter (29) (7) is connected to the input side. The output of the A/D converter (29) is connected to a microcomputer unit (32), and a position detection signal is read based on control described later.

On the other hand, one end of the switch (20) is installed on the common side (ground), and the other end is connected to the constant voltage power supply (A) via the resistor (33), and is connected to the low-pass filter (34).
) is entered. In the low-pass filter (34),
The output of the low-pass filter (34) is connected to the microcomputer unit (32) via the waveform shaping circuit (35), and is converted into a rectangular wave by the waveform shaping circuit (35). The signal is input after being formatted, and the signal when the switch (20) is turned on is read based on the control described later.

The microcomputer unit (32) is a CPU,
Ts standard, lock, clock generator, ROM,
RAM.

It is composed of an I10 board, etc., and operates according to a ROM in which control software, which will be described later, is written.

The output side of the microcomputer unit (32) is connected to the drive unit (3B). The drive unit (36) drives the FETs (37), (40) by control signals from the booster circuit and microcomputer unit (32) for driving the FETs (37), (40).
39) or a switching circuit for switching FETs (38) and (40). The output of the drive unit (36) is an FET (37).

(40) are connected to the respective gate terminals of FET (37).
).

The respective drain terminals of (40) are connected to the battery (
41) is connected to the positive side. FET (37)
, (40) and FETs (38), (39)
The drain terminals of the FET (40) and the drain terminal of the FET (38) are connected to each other, and
The connection between the source terminal of T (37) and the drain terminal of FET (18) is connected to the motor (13). FET
The drain terminals of (38) and (39) are connected and placed on the common side.

In addition, the positive terminal of the battery (41) is connected to a constant voltage circuit (
42) is connected. The output (A) of this constant voltage circuit (42) is a constant voltage lower than the battery voltage (41), and includes low pass filters (23), (34), a waveform shaping circuit (35), an operational amplifier (25), and a microcomputer unit. ) (32) and other control circuits.

In such a device, control processing is performed according to the flowchart shown in FIG. In addition, P in Fig. 3 ~1), e++ dub -; -, -/9 First, when the power is turned on, control is started, and in step P1, the registers in the CPU and the data in the RAM are It is cleared and the process proceeds to step P2. In step P2, the output signal S3 of the switch (20) is input. Here, if the switch (20) is turned on, S3 becomes a low level, that is, 0.

When the switch (20) is OFF, S3 is at the noise level,
That is, the output voltage (A) of the constant voltage circuit (42) becomes approximately equal to "1". In step P3, the switch (20
) is rQJ, that is, is ON. If it is OFF, since 53=1, the process jumps to step P2 and waits for the input of the output signal from the switch (20).

If the switch (20) is ON, Sol is ~0, so proceed to step P4, input the detection signal S1 of the intermediate position detection means (1B), and first, in step P5, set the reference voltage S2.
Enter. At this time, the detection signal S! and the reference voltage S2 are expressed as shown in FIG.
2 is processed to be S, the deviation height and direction from the middle position of the steering device are calculated, and S20 is determined in step P7. In the case of S20, it is determined that there is no displacement and the process returns to step P2. If S=O, the process advances to step P8. In step P8, the sign of the S value is determined. If positive, the process advances to step P9, where the sign flag is set to Ft-0; if negative, the process proceeds to step PIG, where the sign flag F is set to 1, and in step Fil, the process of S←-5 is performed to convert the absolute value. Then, the process proceeds to step P12, where the dead zone a is added to the S value.
Next, proceed to step PI3 to process S weight ← (S - a) in order to provide become. Therefore, in this state, it is assumed that the steering device is in the middle position, and the process jumps to step P2 and waits for a switch input.

On the other hand, if the value of S is larger than the dead zone, the process proceeds to step PI4 since Sl>0, and the sign flag is determined in step P9 or PIG, and the direction signal of the electric motor (13) is sent to the drive unit (36). Output. At this time, the drive unit (36) is an FET (37).

(38) or FETs (40) and (38) are set to a controllable state.Next, the process proceeds to step P+5, and the set motor drive signal is output to drive 22) (3B). At this time, the drive unit (36) is an FET
(37) or FET (40) is turned on and FET (39) or (38) is turned on according to the drive signal.
WM drive is performed, and the process returns to step P4 to repeat this process until the steering device returns to the middle position.

Therefore, when you want to return the steering device to the middle position, by turning on the switch (20),
The steering system automatically returns to the intermediate position based on the detection signal from the intermediate position detection means (16).

In the above embodiment, an example was explained in which the shaft-like member (fourth shaft) of the steering device to which the power of the electric motor is transmitted is provided with a position detecting means, but the steering device shown in FIG. It is also possible to provide position detection means on the first shaft to which is fixed.

The differences from FIG. 1 in the above embodiment will be explained based on FIG. 5. The first car (2) to which the steering wheel (1) is fixed is provided with a large diameter pulley (11) in one piece. The electric motor (
A small-diameter pulley (14) is installed in one piece on the rotating shaft of 13), and both pulleys (11).

A timing belt (15) is wound around (14), and the rotation of the electric motor (13) is decelerated and transmitted to the first shaft.

Also, a small diameter pulley (50) is integrally provided on the opposite side of the small diameter boob 9 (14) of the electric motor (!3).
), a potentiometer (53) is provided almost parallel to the
A large-diameter pulley (51) is installed in one piece on the output shaft of this potentiometer, and a timing bell (52) is wound between the small-diameter pulley (50) and the large-diameter pulley (51). . Then, the rotation of the electric motor (13) is decelerated and transmitted to the potentiometer (53), and the output of the potentiometer (53) is input to the control device (19). In this way, the potentiometer (53) constitutes the middle position detection means of the steering device, and it is possible to obtain the same effect as in the above embodiment.

In the above two embodiments, the switch means is a manual switch that is turned on by the driver's will, but the switch means is not limited to this, and the switch means may be linked to the ignition key. The steering wheel may be configured so that the steering wheel is automatically returned to the middle position when the engine is started, and the electric motor is also used as an electric motor for electric power steering to reduce the steering force of the steering system. It is advantageous in terms of cost and space.

(Effects of the Invention) As explained above, according to the present invention, the steering device can be automatically returned to the middle position by turning on the switch, so when the vehicle is stopped, parking on a narrow road, When the vehicle is parked in a garage in a bad garage environment, it is easy to stop the vehicle straight, and when the vehicle is to be started, the vehicle can be steered from a straight position, making it easy to start.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a schematic perspective view of the steering wheel installed, FIG. 2 is a schematic perspective view of the control device, and FIG. 3 is a schematic diagram of the intermediate position return process. FIG. 4 is a diagram showing the relationship between the displacement from the intermediate position and the detection signal, and FIG. 5 is a schematic perspective view showing a steering device according to another embodiment. In the drawing. 13... Electric motor, 16.53... Intermediate position detection means, 19...
...Electric motor control means (control device), 20...
It is a switch means. Patent applicant: Honda Motor Co., Ltd. Representative: Patent attorney (Part 2)
Patent Attorney Kuni Ohashi, Patent Attorney
Yuki Koyama Patent Attorney Field 1
) Shigeru LD et al.'s plan is corrected by placing A in Figure 1 and Figure 4.

Claims (1)

[Scope of Claims] 1) Position detecting means for detecting a steering position of a steering system, a switch means, and when the switch means is turned on, driving and controlling an electric motor based on an output signal from the position detecting means to detect the steering position of the steering system. 1. An intermediate position return device for a steering device, comprising: electric motor control means for returning the system to an intermediate position. 2) Claim 1, wherein the switch means is constituted by a manual switch provided in the vehicle interior near the driver's seat.
A device for returning the steering device to an intermediate position as described in Section 3.