JP2837447B2 - Outboard motor power steering system - Google Patents

Description

The present invention relates to a power steering apparatus for an outboard motor for power assisting the steering of an outboard motor, and more particularly to suitably controlling an assist force. The present invention relates to a power steering device for an outboard motor.

(Prior Art) FIG. 8 is a perspective view showing a conventional steering device for an outboard motor.

Steering wheel 2 installed in driver's seat of hull 1
Is operated by the operator, the gear in the gear box 4 rotates via the steering shaft 3, and the inner cable 6 of the steering cable 5 is operated by this gear. The steering cable 5 has an inner cable 6 housed in an outer cable 7, and the inner cable 6 is a push-pull cable. Further, the steering cable 5 extends from the gear box 4 to the rear of the hull 1 to which the outboard motor is attached.

On the other hand, as shown in FIG. 2 (the outboard motor main body is also the same as the conventional example), the outboard motor 8 is provided with a swivel The bracket 11 and the clamp bracket 12 are attached. The outboard motor main body 10 is
It is horizontally rotatably supported by a swivel bracket 11 via a pilot shaft (not shown) fixed to 10.
The swivel bracket 11 is vertically rotatably supported by the clamp bracket 12 via a clamp bracket shaft 13. The outboard motor main body 10 is attached to the hull 1 by the clamp bracket 12 gripping the transom of the hull 1.

The outer cable 7 of the steering cable 5 shown in FIG. 8 is fixed to one end of the clamp bracket shaft 13. The clamp bracket shaft 13 has a hollow cylindrical shape, and the inner cable 6 extends through the clamp bracket shaft 13 to the opposite side. A link mechanism 14 is attached to the tip of the inner cable 6. The link mechanism 14 includes a substantially L-shaped drag link 15,
The steering bracket 16 is connected to and configured.
The drag link 15 is fixed to the distal end of the inner cable 6 of the steering cable 5, and the steering bracket 16 is fixed to the outboard motor body 10. Accordingly, the outboard motor main body 10 is horizontally rotated via the pilot shaft by the movement of the inner cable 6 of the steering cable 5 via the link mechanism 14, and is steered.

However, in such a conventional steering system based only on the manual operation of the operator, the outboard hull depends on the navigation conditions of the hull 1, that is, the wave, wind, hull speed, trim angle of the outboard motor, and rotation direction of the propeller. Since the steering load changes when the aircraft is steered, steering may be difficult. Here, the trim angle of the outboard motor refers to an angle α (see FIG. 2) between the transom of the hull 1 and a drive shaft (not shown) of the outboard motor 8, and the drive shaft of the outboard motor 8 is In order to transmit the power from the engine to the propeller 49, it is extended in the drive shaft housing 9 in the longitudinal direction. Specifically, the trim angle α of the outboard motor is such that the outboard motor 1 is tilted up to, for example, about 80 degrees from a state in which the transom of the hull 1 and the drive shaft are parallel (angle 0). . The maximum trim angle of the outboard motor depends on the type and size of the ship.

In order to eliminate the weight of the steering, a hydraulic power steering device that assists the steering by pumping oil from a hydraulic pump has been conventionally proposed. However, in this hydraulic power steering apparatus, since the power source of the hydraulic pump depends on the power of the outboard motor itself from the drive shaft, the hydraulic pressure generated by the hydraulic pump depends on the rotation speed of the drive shaft (engine speed). Changes. For this reason, there is a possibility that the assist force cannot be appropriately controlled according to the difference in the navigation conditions.

(Problems to be Solved by the Invention) As described above, in the conventional outboard motor steering apparatus, it becomes difficult to steer the outboard motor depending on the navigation conditions of the hull. Further, in the conventional hydraulic power steering device, there is a possibility that the assist force cannot be suitably controlled according to the navigation conditions.

The present invention has been made in view of the above circumstances, and has as its object to provide an outboard motor power steering device that can easily and appropriately steer an outboard motor with a small steering load under any navigation conditions. .

[Configuration of the invention]

According to the present invention, a steering cable is operatively connected to a steering wheel installed on a hull, and the steering cable is connected to an outboard motor body via a link mechanism. The outboard motor main body is horizontally rotated via the steering cable and link mechanism by the steering load acting on the outboard motor for steering, and the main part of the power steering device is installed on the swivel bracket. A steering torque sensor for detecting a steering load applied to a steering wheel, an engine speed sensor for detecting an engine speed of the outboard motor, a trim angle sensor for detecting a trim angle of the outboard motor, and the link mechanism. Power that is connected to provide an assist force to this link mechanism An assist device, a controller that generates an optimal assist force for the power assist device based on a torque signal from the torque sensor, an engine speed signal from the engine speed sensor, and a trim angle signal from the trim angle sensor. , Is characterized by having.

(Operation) Therefore, according to the power steering apparatus for an outboard motor according to the present invention, the controller controls not only the steering torque signal from the steering torque sensor and the engine speed signal from the engine speed sensor, but also the trim from the trim angle sensor. Since the assist force is determined also in consideration of the angle signal, an optimum assist force can be generated.

For example, in an outboard motor with a forward rotation propeller, when the trim angle is small, the assist force at the time of left steering is made larger than the assist force at the time of right steering, and when increasing the trim angle of the outboard motor, the assist force at the time of left steering is used. The force is gradually reduced, and the assist force during right steering is gradually increased to approximately the same level. In this manner, an optimal assist force suitable for the running conditions is generated, and the outboard motor can be easily and appropriately steered with a small steering load.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 4 shows a power assist device and the like in an embodiment of a power steering device for an outboard motor according to the present invention,
FIG. 4 is a horizontal sectional view in FIG. 3. In this embodiment, the same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 3, a power assist device 22 of a power steering device 21 is fixed by bolts 23 in front of the swivel bracket 11 of the outboard motor 20 (on the hull 1 side). The power steering device 21 further includes a steering torque sensor 24, an engine speed sensor 25 shown in FIG. 1, a trim angle sensor 26, a controller 27, and the like.

The power assist device 22 shown in FIG. 4 is configured such that a rack 33, a pinion 34, and reduction gears 35, 36 connected to the pinion 34 are housed in a housing 37.
In particular, both ends of the rack 33 are covered by a stretchable bellows case 32 fixed to a housing 37. The rack 33 extends horizontally in the width direction of the hull 1 and has a pinion.
Engage with 34. The reduction gears 35 and 36 are bevel gears, and the reduction gear 36 is fixed to the shaft of the motor 38. The axis of the motor 38 is installed horizontally in the width direction of the hull 1.

An assist arm 39 is fixed to one end of the rack 33, and the assist arm 39 is attached to the drag link 15 of the link mechanism 14. As shown in FIG. 5, the mounting state is such that the assist arm 39 and the inner cable 6 are overlapped with each other, the tip of the drag link 15 is penetrated through the assist arm 39 and the inner cable 6, and the washer 40 is provided.
And is fixed by a nut 41 via Therefore, the pinion 34 rotates through the reduction gears 35 and 36 by the driving of the motor 38 in FIG. 4, the rack 33 linearly moves, and an assist force is applied to the drag link 15 via the assist arm 39.

On the other hand, the steering torque sensor 24 is bolted to the clamp bracket 12 by the fixing bracket 42. Further, the steering torque sensor 24 is connected to the outer cable 7 of the steering cable 5 via the sensor bracket 43. Therefore, when the operator operates the steering wheel 2 shown in FIG. 12 and the inner cable 6 of the steering cable 5 moves with respect to the outer cable 7, the outer cable 7 shown in FIG.
The steering torque sensor 24 detects the steering load with a potentiometer or the like and transmits it to the controller 27 as a steering torque signal.

The engine speed sensor 25 shown in FIG. 1 detects the speed of an engine (not shown) mounted in the outboard motor main body 10 and transmits an engine speed signal to the controller 27.

Further, the trim angle sensor 26 detects a trim angle of the outboard motor 20 in which the outboard motor main body 10 has slightly rotated from the vertical direction to the horizontal direction about the clamp bracket shaft 13 and outputs the trim angle signal. Output to the controller 27.

As shown in FIG. 1, the controller 27 includes an arithmetic unit 44, an amplification unit 45, an abnormality detection unit 46, a torque control signal output circuit 47, and a PWM (PULSE WIDTH MODULE) control unit 4.
8 and so on.

The arithmetic unit 44 converts the steering torque signal from the steering torque sensor 24 amplified by the amplification unit 45, the engine rotation number signal from the engine rotation number sensor 25, and the trim angle signal from the trim angle sensor 26 into signals. Then, a current value to the motor 38 is calculated according to each of these signals. That is, when the steering torque is large, the current value to the motor 38 is increased, and when the engine speed is large, the current value to the motor 38 is decreased. Further, when the trim angle of the outboard motor (hereinafter simply referred to as trim angle) is small, the assist force at the time of left steering is made larger than the assist force at the time of right steering as shown in FIG. 6, and the trim angle becomes large. , The assist force during left steering is gradually decreased, and the assist force during right steering is gradually increased. FIG. 6 shows a case where the steering speed is constant. Arithmetic unit 44
Calculates the current value to the motor 38 by comprehensively judging them, and determines the assist force.

Here, the reason why the assist force at the time of left-right steering is made different according to the magnitude of the trim angle is as follows.

7 (A) and 7 (B) show the relationship between the steering direction and the steering force when steering at a constant speed. FIG. 7 (A) shows a case where the trim angle is small, and FIG. 7 (B) shows a case where the trim angle is large. Show the relationship. Seventh
According to FIG. (A), in the case of a forward rotation propeller, when the left steering is attempted when the trim angle is small, the propeller 49 (FIG. 2)
It is necessary to increase the steering force due to the non-hydraulic force generated by the right rotation of the steering wheel. Therefore, when the trim angle is small, it is necessary to make the steering force during left steering larger than the steering force during right steering. On the other hand, when the trim angle increases, the steering force at the time of left steering gradually decreases, the steering force at the time of right steering gradually increases, and the left and right steering forces become substantially equal as shown in FIG. 7 (B). Become. Based on the above circumstances, the assist force at the time of left / right steering is changed according to the magnitude of the trim angle.

The current value signal to the motor 38 determined by the arithmetic unit 44 is
As shown in FIG. 1, a torque control signal output circuit
47 and the PWM control unit 48
To 9. This power drive unit 49
, And amplifies the current value signal for driving the motor 38 and outputs the amplified signal to the motor 38.

On the other hand, the abnormality detection unit 46 of the controller 27
When a signal that cannot be considered normally is output from each of the sensors 24, 25, and 26, for example, because the lead wires of 4, 25, and 26 are cut, the signal is output to the arithmetic unit 44 as abnormal. This abnormal signal is
For example, when the signal is input to the 44, the failsafe signal is output from the arithmetic unit 44 to the torque control signal output circuit 47. At this time, the torque control signal output circuit 47
Reduces or cuts off the current value signal of the motor 38 by half. In this manner, the controller 27 also performs control at the time of abnormality.

According to the above embodiment, the controller 27 controls the steering torque from the steering torque sensor 24 and the engine speed sensor 25.
The value of the supply current to the motor 38 is determined based on the engine speed from the motor, and the supply current to the motor 38 is adjusted according to the magnitude of the trim angle from the trim angle sensor 26. For example, when the trim angle is small, the motor 38 is set so that the assist force during left steering becomes larger than the assist force during right steering.
Adjust the current to the. As a result, the assist force can be optimally controlled according to the navigation conditions, and the outboard motor can be easily and appropriately steered with a small steering load.

〔The invention's effect〕

As described above, according to the power steering apparatus for an outboard motor according to the present invention, a steering torque sensor for detecting a steering load applied to a steering wheel, and an engine speed sensor for detecting an engine speed of the outboard motor are provided. , A trim angle sensor for detecting a trim angle, a power assist device connected to a link mechanism for applying an assist force to the link mechanism, a torque signal from the torque sensor, an engine speed signal from the engine speed sensor And a controller that generates an optimal assisting force for the power assist device based on a trim angle signal from the trim angle sensor, and generates an optimal assisting force suitable for navigation conditions. Thus, the outboard motor can be easily and appropriately steered with a small steering load.

[Brief description of the drawings]

FIG. 1 is a block diagram mainly showing a controller in an embodiment of a power steering apparatus for an outboard motor according to the present invention, FIG. 2 is a side view showing an outboard motor to which FIG. 1 is applied,
FIG. 3 is a perspective view mainly showing a power assist device of one embodiment, FIG. 4 is a horizontal sectional view of FIG. 3, and FIG.
FIG. 6 is a graph showing the relationship between the trim angle and the assisting force. FIGS. 7A and 7B show the relationship between the steering direction and the steering force, and FIG. When (B)
FIG. 8 is a perspective view showing a conventional power steering apparatus for an outboard motor, which shows the relationship when the trim angle is large. DESCRIPTION OF SYMBOLS 1 ... Hull, 2 ... Steering wheel, 5 ... Steering cable, 10 ... Outboard motor main body, 14 ... Link device, 15 ... Drag link, 16 ... Steering bracket, 22 ... Power assist device, 24 ... steering torque sensor, 25 ... engine speed sensor, 26 ... trim angle sensor, 27 ... controller, 44 ... arithmetic unit.

Claims (1)

(57) [Claims] A steering cable is operatively connected to a steering wheel installed on a hull, the steering cable is connected to an outboard motor body via a link mechanism, and the steering wheel is actuated by a steering load acting on the steering wheel. The main body of the power steering device is installed on the swivel bracket while the main body of the outboard motor is turned horizontally via a cable and a link mechanism, and the power steering device is configured to reduce a steering load applied to the steering wheel. A steering torque sensor for detecting, an engine speed sensor for detecting the engine speed of the outboard motor, a trim angle sensor for detecting the trim angle of the outboard motor, and an assist force applied to the link mechanism by being connected to the link mechanism. A power assist device for imparting
A controller that generates an optimal assist force for the power assist device based on a torque signal from the torque sensor, an engine speed signal from the engine speed sensor, and a trim angle signal from the trim angle sensor. A power steering device for an outboard motor.