JPS6235959B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electro-hydraulic steering system suitable for small marine vessels.

Small vessels equipped with an electric-hydraulic steering system should be equipped with a separate manual steering device in case a failure occurs in the electric or hydraulic system and when delicate maneuvers are required. Sometimes.
In general, a simple and safe rod rudder is often used as a means of manual steering, but when switching to rod rudder steering, the electric-hydraulic steering system can be quickly switched from the helm. It is necessary to separate it, and it is not desirable to take time to separate it, especially in shallow water where there are many underwater obstacles.

However, even if the hydraulic cylinder piston device for steering drive of the electro-hydraulic steering device and the rudder rotation fitting are disconnected and the rudder is attached to the fitting and the rudder is switched to a rod rudder, the electric-hydraulic steering If the electrical system and hydraulic system of the device remain in operation, the hydraulic cylinder piston device will operate when the helm is rotated, and it is also designed to operate in conjunction with the helm without touching the helm. The potentiometer that generates the comparison actual steering angle signal generates an output when the rudder is steered, and there is always a deviation between the output and the signal from another potentiometer that generates the command signal that is linked to the steering wheel. becomes. In the electro-hydraulic steering system, the pump drive motor and directional solenoid valve are designed to operate in order to eliminate the above deviation to zero, so if the above deviation always occurs, the pressure oil will The piston of the hydraulic cylinder piston system, which is always sent to the hydraulic cylinder piston system and is free with respect to the rudder, will end up at one of the stroke ends. Therefore, the pump discharge side circuit in the hydraulic system is held at the upper limit pressure set by the built-in relief valve. As a result, the temperature and oil temperature of the DC motor for driving the pump rise, and if left as is, there is a risk that the motor and hydraulic equipment may be burnt out.

One possible way to prevent this is to install a cooler or use a motor with sufficient continuous rating, but this is not easy in terms of installation space and cost in small ships. It is also conceivable to open the main power switch of the electric-hydraulic steering system when switching to the rod rudder, but when switching to the rod rudder in an emergency, it is recommended to open the main switch in the wheelhouse and the rudder located at the stern. This is not a good idea as there is no time to do the two-step work of attaching the rudder rod using the rotating metal fitting, and you may forget to open the main switch.

This invention does not cause the above-mentioned disadvantages, and
An improved electro-hydraulic steering system equipped with an automatic circuit that forcibly stops the operation of the solenoid valve and motor if the aforementioned deviation of the electro-hydraulic steering system continues to occur for a certain period of time determined by the characteristics of the system. The purpose is to provide a device.

In order to achieve this purpose, this invention
A first potentiometer that works in conjunction with a steering wheel to output a command signal according to the rotation angle of the steering wheel; and a second potentiometer that works in conjunction with a ship's rudder to output a comparison signal that corresponds to an actual steering angle. , a steering drive hydraulic cylinder piston device detachably connected to the rudder rotation fitting; a solenoid valve for supplying and discharging pressure oil from a pump to the hydraulic cylinder piston device and switching its direction; A prime mover for driving the pump, and outputting an operating signal to the solenoid valve so that the deviation between the command signal and the comparison signal becomes zero, and operating the prime mover while the deviation occurs. In an electro-hydraulic steering system equipped with a control circuit that outputs an operating signal, when the rudder rotation fitting and the hydraulic cylinder piston device are disconnected and a manual steering tool is attached to the fitting, the prime mover The above-mentioned deviation continued to occur beyond the predetermined time required to rotate the ship's rudder by the maximum deflection angle of the ship's rudder by the hydraulic cylinder piston device controlled by the control circuit so as not to operate continuously. The present invention further includes a detection circuit for detecting this, and a stop circuit for forcibly stopping the output of the control circuit based on the output of the detection circuit.

Next, this invention will be explained with reference to the drawings. Fig. 1 is a mechanical system configuration diagram of a general electro-hydraulic steering device, where 1 is a rudder shaft, and 2 is a rudder fixed to the rudder shaft. Rudder rotation fitting (rudder arm) for rotating the ship, 3
Reference numeral 4 denotes a detachable joint, and 4 is a hydraulic cylinder piston device for steering and driving the metal fitting 2, that is, the rudder, through the detachable joint 3. The detachable joint 3 is shown enlarged in FIG. Both cylinder chambers 4a and 4b of the hydraulic cylinder piston device 4 are connected to ports A and B of a solenoid switching valve 6 via pilot-operated check valves 5a and 5b, respectively, and a port of a pump 7 is connected to the P port of the solenoid valve. A tank 8 is connected to the discharge port and the T port. A relief valve 9 that determines the maximum pressure of the circuit is connected between the above PT ports, and the motor 1
When one solenoid device 6a of the electromagnetic valve 6 is energized, the discharge pressure oil of the pump 7 driven by the pump 7 is supplied into the head side cylinder chamber 4a via the check valve 5a, and the other solenoid device 6b is supplied to the head side cylinder chamber 4a through the check valve 5a.
When energized, the hydraulic cylinder piston device 4 is supplied to the rod side cylinder chamber 4b via the check valve 5b, and the hydraulic cylinder piston device 4 is moved to the metal fitting 2 by rotation of the motor 10 and switching of the energization of the solenoid devices 6a and 6b.
Rotate the rudder left and right via the These motors 1
0 operation control and energization control of the solenoid devices 6a and 6b are performed by a control circuit 11, and an input signal to the control circuit 11 is an input signal from a first potentiometer 13 that is linked to the rotation of the steering wheel 12. These are two signals: a command signal corresponding to the rotation angle of the steering wheel, and a comparison signal corresponding to the actual rudder angle from the second potentiometer 14 interlocked with the rudder rotation fitting 3, and the control circuit 11 outputs an actuation signal to rotate the motor 10 when there is a deviation between these two input signals, and an operation to energize either of the solenoid devices 6a, 6b so as to make the deviation zero. 15 in Figure 1
16 is a power source such as a battery, and 16 is a main switch of the electrical system including the control circuit 11. Furthermore, although the pump 7 is driven by a motor 10 in FIG. 1, an internal combustion engine may be used instead of this motor, and in this case, the starting and stopping of the internal combustion engine is controlled by an activation signal from a control circuit. It will be controlled.

In the above case, when steering is performed by the electro-hydraulic steering device, the command signal from the potentiometer 13 changes depending on the rotation of the steering wheel 12, and the comparison signal corresponding to the actual steering angle is sent from the potentiometer 14. A deviation occurs between the two. This deviation has a positive or negative polarity determined by the rotating direction of the steering wheel, and when the steering wheel is rotated to the left (counterclockwise), for example, a positive deviation occurs, and one solenoid device 6a continues until the deviation becomes zero. An operating signal to energize the solenoid device 6b is output from the control circuit, and conversely, when the steering wheel is rotated to the right (clockwise), a negative deviation occurs and an operating signal energizes the other solenoid device 6b until it becomes zero. is output from the control circuit, and furthermore, in any of the above cases, an operating signal for rotating the motor 10 while the deviation exists is output from the control circuit. When the solenoid device 6a is energized by the output from the control circuit 11 described above, pressure oil is supplied to the head side cylinder chamber 4a, and the rudder is rotated in the steering direction via the metal fitting 2. Conversely, when the solenoid device 6b is energized, the rudder is rotated in the direction of the surface rudder. The potentiometer 14 is controlled by the rotation of the rudder.
When the comparison signal from the potentiometer 13 approaches the command signal from the potentiometer 13 and these two signals match, each output from the control circuit 11 stops and the motor 10
is stopped and the solenoid valve 6 is returned to neutral, and the rudder maintains a rudder angle corresponding to the rotation angle of the rudder wheel 12.

When switching the steering by the electric-hydraulic steering device to the steering by the rod rudder, the detachable joint 3 connecting the piston rod tip of the hydraulic cylinder piston device 4 and the metal fitting 2 is removed, and a rudder rod is attached instead. At this time, after removing the detachable joint 3, returning to the wheelhouse and opening the main switch 16,
The electro-hydraulic steering system will henceforth remain inactive, so that even if the rudder is rotated by the rudder and the potentiometer 14 is activated, it will have no effect on the system. The aforementioned problems such as motor burnout and oil temperature rise do not occur. However, with this system, it is common to forget to turn off the main switch when busy with steering, and the detachable joint and main switch are located far apart, causing various inconveniences.

In this invention, the above configuration is provided with an electrical system shown in FIG. 3. To describe this invention in detail together with embodiments, FIG. 3 is a circuit diagram showing the control circuit 11 shown in FIG. The portion 18 shown in FIG. 1 is a specific example of the control circuit 11 in FIG. 1, but in FIG.
6b and the motor 10 are shown together. In this specific control circuit 18, the potentiometer 13
A differential amplifier 19 compares a set voltage as a command signal from the potentiometer 14 with a feedback voltage as a comparison signal from the potentiometer 14, and when the deviation output from the differential amplifier 19 is positive. It has a comparator 20a that operates and a comparator 20b that operates when the deviation output is negative, and these comparators 20a and 20b produce an output when the input deviation signal exceeds a predetermined dead band level. The transistor 21a, which is turned on by the output of the comparator 20a, is connected to one solenoid device 6.
Transistor 21b, which is similarly turned on by the output of comparator 20b, constitutes a switching element for energizing the other solenoid device 6b, and also constitutes a switching element for energizing the other solenoid device 6b. The transistor 21c, which becomes conductive when an output is generated, constitutes a switching element for energizing the motor 10, and these transistors 21a, 21b, and 21c are designed to be conductive only while their base inputs, that is, the comparator outputs are present.

For example, by rotating the steering wheel, potentiometer 1
When the set voltage from the differential amplifier 19 changes and a negative deviation occurs between the set voltage and the feedback voltage, only one comparator 20a is activated by the output from the differential amplifier 19, and the output from the transistors 21a and 21a is activated.
21c is electrically connected, one solenoid device 6a and the motor 10 are energized, and as a result, the pump 7 supplies pressure oil to the head side cylinder chamber 14a, and the rudder rotates in one direction. Since the potentiometer 14 is linked to the rudder, the rotation of the rudder causes the feedback voltage to change closer to the set voltage, and at the point where both voltages match, the output of the differential amplifier 19 stops. However, the output of the comparator 20a disappears and the transistors 21a and 21c return to their cut-off state, thereby stopping the motor 10 and returning the solenoid valve 6 to neutral, thereby stopping the ship's rudder. Similarly, when the steering wheel is rotated in the opposite direction to the above, only the other comparator 20b produces an output, and the other solenoid device 6b and motor 10 operate via the transistors 21b and 21c, and the ship's rudder It will rotate in the opposite direction. In this case, stopping the motor 10 and returning the solenoid valve 6 to neutral are the same as described above. In this way, the rudder can be rotated in the steering direction and the surface rudder direction by turning the steering wheel 12 left and right.

By the way, the piston operating speed of the hydraulic cylinder piston device 4, that is, the rotation speed of the rudder, is determined by system specifications such as the rotation speed of the motor 10, the discharge amount of the pump 7, and the cylinder diameter of the hydraulic cylinder piston device 4. It is a constant value. Therefore, if the time required for the rudder to rotate to the maximum deflection angle is _tp , this _tp is also a constant value unique to the system, and the differential amplifier 19 changes the deviation output. The time during which the signal continues to occur is usually less than or equal to this t _p , and the comparator 20a or 20b always stops outputting within the t _p time. However, when the detachable joint is removed and the rudder is rotated by the rudder rod in order to switch to the rod rudder, the rudder wheel 12 remains at a certain rotation angle and the command signal from the potentiometer 13 remains at a constant value. while the potentiometer 14, which is always connected to the rudder, emits a comparison signal that changes in accordance with changes in the rudder angle by the rudder, and therefore controls the control circuit 19.
The differential amplifier 19 may continue to produce a deviation output beyond the above-mentioned time _tp , and as a result, the motor 10 continues to drive the pump 7, causing the above-mentioned inconvenience due to continuous operation. .

In this invention, it is detected that the deviation output continues to occur beyond the above-mentioned time _tp , and accordingly, the motor 10 and the solenoid devices 6a, 6b are automatically controlled.
It is designed to cut off the influence of

That is, in FIG. 3, a base input is applied to the base of the transistor 21c if either one of the comparators 20a and 20b is producing an output, which means the existence of the deviation signal. In order to forcibly turn off each transistor 21a, 21b, 21c when the duration time of this base input exceeds the above-mentioned t _p , this invention includes a detection circuit 22 and an automatic stop circuit 23 in the control circuit 18. It is attached.

The detection circuit 22 generates an output when the base input of the transistor 21c continues to exist for a period of time _tp , and includes a charge/discharge circuit consisting of a capacitor 24, resistors 25, 26, and diodes 27, 28, and a comparator. 29,
Further, the automatic stop circuit 23 includes transistors 30a, 3
0b and 30c. The voltage V _c between the capacitor 24 and the ground is determined by the comparator 20a, 20
While at least one of b is producing an output, the resistance value R _p of the resistor 25 and the capacitor 2
₄ , and when the output of the _comparator 20a or _20b stops, the resistance value of the resistor ₂₆ R1 It rapidly descends, drawing a discharge curve determined by and C _p . Comparator 29
When _Vc exceeds the above-mentioned predetermined level, it produces an output and makes all of the transistors 30a, 30b, and 30c conductive, and the transistors 21a and 21
b, 21c, which is connected to the one to which the base input is applied, becomes conductive and forcibly cuts off the base input. For example, comparator 20a
continues to produce an output beyond the time _tp , the comparator 29 produces an output and the transistor 30a
and 30c become conductive, lowering the base potential of the previously conductive transistors 21a and 21c to near the emitter potential and turning off the transistors 21a and 21c. This forcibly cuts off the power to the The time t _x from when the capacitor 24 starts charging, that is, when the comparator 20a or 20b produces an output until the comparator 29 produces an output, is determined by the time constant R _p C _p and the operating input level of the comparator 29. Decided,
By choosing t _x to be larger than t _p , the normal electric
The stop circuit 23 is not activated when the hydraulic steering system is activated.

That is, during the operation of a normal electro-hydraulic steering system, the time during which the output from the comparator 20a or 20b continues is within t _p as described above, and therefore the resistance value R p of the resistor 25 is less than the resistance value R _p of the resistor 26.
If the resistance value R _{1 is} set very small, the charge in the capacitor 24 will be rapidly discharged via the diode 27 and the resistor R ₁ with a discharge time constant R ₁ C _p that is extremely smaller than the charging time constant R ₁ C p. Therefore, the capacitor 24 can be completely discharged and V _c can be reduced to zero during the short output stop time of the comparators 20a and 20b, and the capacitor 24 can always be charged from zero potential by the next comparator output. It is something. As a result, even if the comparators 20a and 20b alternately produce outputs, such as when the steering wheel 12 is suddenly turned (zigzag steering), the capacitor can be 24 of the electric charges can be discharged tightly, thereby preventing malfunctions during normal operation of the control circuit.

The diode 28 is for applying self-feedback to hold the output of the comparator 29 immediately when the comparator 29 produces an output, and a separate latch circuit may be provided for the same purpose.

Furthermore, in FIG. 3, an alarm device 31 is provided which is activated by the output of the comparator 29, and this can be considered to be a buzzer, a bell, an indicator light, or a relay for controlling the operation of these.

The above detection circuit 22 and stop circuit 2 in the present invention
3 prevents the continuous operation of the electro-hydraulic steering device after switching to manual steering such as a rod rudder, and after that operation, the steering is switched from the rod rudder to the electric-hydraulic steering device again. To return it, either turn off the main switch 16 to discharge the charge in the capacitor 24 and return the comparator 29, or provide a return switch 17 and temporarily close it as shown by the broken line in FIG. After performing the following operations, it is sufficient to proceed to steering using the electro-hydraulic steering device.

Furthermore, when the present invention is applied to a mobile electro-hydraulic steering device in which the pump 7 is driven by an internal combustion engine via a pulley or the like instead of the motor 10, the solenoid devices 6a and 6b of the electromagnetic valve 6 may be used.
It may also be possible to automatically stop only that.

As described above, according to the present invention, continuous operation of the electric system and hydraulic system during steering with a rod rudder is prevented by completely automatic operation, and therefore troubles such as motor burnout and oil temperature rise are avoided. This is what prevents such problems from occurring.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an example of the basic overall configuration of an electro-hydraulic steering device, Fig. 2 is an enlarged side view of a detachable joint portion, and Fig. 3 is a main part showing an embodiment of the present invention. It is a circuit diagram. 1... Rudder shaft, 2... Rudder rotation fitting, 3... Detachable joint, 4... Hydraulic cylinder piston device, 6...
Solenoid valve, 6a, 6b... Solenoid device, 7...
Pump, 10... Motor, 11, 18... Control circuit, 12... Steering wheel, 13, 14... Potentiometer, 15... Power supply, 16... Main switch,
19... Differential amplifier, 20a, 20b... Comparator, 21a, 21b, 21c... Transistor, 22... Detection circuit, 23... Automatic stop circuit,
24... Capacitor, 25, 26... Resistor, 2
7, 28...Diode, 29...Comparator, 30a, 30b, 30c...Transistor,
31...Alarm device.

Claims (1)

[Claims] 1. A first potentiometer that works in conjunction with the rudder to output a command signal according to the rotation angle of the rudder, and a second potentiometer that works in conjunction with the rudder to output a comparison signal that corresponds to the actual rudder angle. a hydraulic cylinder piston device for steering drive which is detachably connected to the rudder rotation fitting; and a solenoid valve for supplying and discharging pressure oil from a pump to the hydraulic cylinder piston device and for switching the direction thereof. , to output an operating signal to the electromagnetic valve so that the deviation between the prime mover for driving the pump, the command signal and the comparison signal becomes zero, and to operate the prime mover while the deviation occurs. In an electro-hydraulic steering system equipped with a control circuit that outputs an activation signal, when the rudder turning fitting and the hydraulic cylinder piston device are disconnected and a manual steering tool is attached to the fitting, the above-mentioned In order to prevent continuous operation of the prime mover, the deviation continues to occur for a period exceeding a predetermined time required to rotate the rudder by the maximum deflection angle of the rudder by the hydraulic cylinder piston device controlled by the control circuit. An electro-hydraulic steering system, further comprising: a detection circuit for detecting that the detection circuit has turned off; and a stop circuit for forcibly stopping the output of the control circuit based on the output of the detection circuit.