JPH0136720Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a steering device.

A steering system that uses electro-hydraulic servo generates an electric signal by rotating a synchro electric machine that issues a steering command signal with the steering wheel, and then passes a predetermined current through an amplifier or the like to the force motor of the steering servo valve to activate the servo valve. Switching, hydraulic pressure is supplied to the steering cylinder to rotate the rudder in a predetermined direction.

In the above-mentioned steering system, in order to move the rudder to a predetermined position as quickly as possible, the larger the proportion of time the servo valve is fully open, the better. That is, if the servo valve is set to be fully open if the difference between the commanded steering angle and the constantly changing steering angle is several degrees or more, the steering speed will be increased.

At this time, for example, if the minimum commanded steering angle (generally referred to as advance angle) that causes the amplifier to output an input current that causes the servo valve to fully open is 4°, the commanded steering of 40° on the steering stand is performed for 0.5 seconds. If it were applied quickly, the servo valve would be fully open in 0.05 seconds, and oil would be rapidly supplied to the hydraulic cylinder, creating an oil hammer and causing abnormal vibrations in the mechanical mechanism that moves the rudder.

The present invention aims to eliminate the above-mentioned drawbacks, and aims to provide a steering system that slows down the switching speed of the servo valve to prevent oil hammer.

Therefore, the steering system of the present invention includes a synchro electric machine for steering commands, and a force motor of a servo valve that operates by receiving a signal from the synchro electric machine via an electric control system, and operates by operating the servo valve. The steering device supplies the servo valve to a hydraulic cylinder to perform desired steering, and is characterized in that a first-order delay control section is inserted into the electric control system so that the operating speed of the servo valve does not exceed a certain speed.

Hereinafter, a steering system as an embodiment of the present invention will be explained with reference to the drawings. Fig. 1 is a block diagram thereof, Fig. 2 is a circuit diagram of a primary delay control section,
Figure 3 is a steering stand, Figure 4 is a graph showing the relationship between the rotation angle θ of the steering wheel and the input current A to the force motor of the servo valve, and Figure 5 is the time T when a step-shaped steering command signal is applied. It is a graph showing the relationship between the amount of movement S of the servo valve based on .

The signal from the synchro electric machine 1 for steering commands passes through an electric control system (command signal circuit) 2, and is sent from the primary delay control section 3 to the amplifier 4 to the force motor 6 of the servo valve 5.
is operated, the oil path of the servo valve 5 is switched, and pressure oil is supplied to the hydraulic cylinder 8 via the hydraulic pipe 7.

The movement of the piston rod 9 operated by hydraulic pressure operates the rudder 13 in the desired direction via the crosshead 10, the connecting rod 11, and the rudder handle 12.

On the other hand, the movement of the piston rod 9 is easy, and the synchro electric machine 15 for feedback is controlled by the pinion 14.
is rotated to generate a signal that cancels the signal from the command synchro electric machine 1, and is transmitted to the amplifier 4 through the feedback signal line 16.

That is, when the rudder 13 moves corresponding to the desired commanded rudder angle, the output from the amplifier 4 becomes zero, the servo valve 5 becomes neutral, and the flow of oil is stopped.

Generally, the command synchro electric machine 1 is the steering stand 1
7 and is rotated from the outside by a handle 18 to issue a desired steering command signal.

In such a steering control device, the input current A to the force motor 6 supplied from the amplifier 4 and the rotation angle θ of the handle 18 are as shown in FIG. 4, and the rotation angle of the handle 18 at which the input current A is maximum is It is generally adjusted to about 10% of the maximum rotation angle of the steering wheel (maximum steerable steering angle). This increases the proportion of the rudder movement at the maximum steering speed when taking a large steering angle, that is, the proportion of the time that the servo valve 5 is fully open. That is, this is to cause the rudder 13 to reach the desired rudder angle quickly.

With a device adjusted in this way, if a commanded steering angle of 45° is rotated at a speed of 0.5 seconds using the steering wheel 18, the input to the force motor 6 is When the current reaches its maximum in about 0.05 seconds, the flow path of the servo valve 5 is suddenly opened, and an oil hammer is generated in the pipeline to the hydraulic cylinder 8, which causes abnormal vibration. Generally, a method for preventing this is to provide an accumulator in the hydraulic pipe 7 to absorb the oil hammer, but this has the disadvantage that the rudder 13 is not stable.

Therefore, if the first-order delay control section 3 shown in FIG. 2 is inserted into the electrical control system, the output current from the amplifier 4 will increase at a constant rate even if the command synchro electric machine 1 is operated in steps. It is not more than that,
The movement of the spool of the servo valve 5 can be made gradual as shown by the solid line in FIG. The dotted line in the figure shows the servo valve 5 when the primary delay control section 3 is not installed.
shows the expected movement of the spool.

In the above explanation, an example was explained in which the first-order delay control section 3 using a resistor R and a capacitor C was inserted between the command synchro electric machine 1 and the amplifier 4.
This first-order delay control section 3 may be inserted between the amplifier 4 and the force motor 6, or the first-order delay control section 3 may be inserted between the amplifier 4 and the force motor 6.
The components are not limited to capacitors, resistors, etc.

Therefore, by inserting a primary delay control section into the electrical control system of the servo valve 5, the operating speed of the spool of the servo valve 5 will not exceed a certain value no matter how sharp the commanded steering angle is. , extremely effective against vibrations in mechanical systems.

In addition, if a mechanical system is equipped with a primary delay mechanism, such as an accumulator in a hydraulic pipe, the rudder becomes unstable (the movement of the piston rod 1 cannot be completely blocked).
Not.

As described above, the steering system of the present invention has the advantage of being able to prevent vibrations of the mechanical mechanism that moves the rudder with a simple configuration in which a primary delay control section is inserted into the electrical control system.

[Brief explanation of drawings]

The figures show a steering system as an embodiment of the present invention. Figure 1 is its block diagram, Figure 2 is a circuit diagram of the primary delay control section, Figure 3 is a steering stand, and Figure 4 is a steering wheel. Figure 5 is a graph showing the relationship between the rotation angle of the servo valve and the input current to the force motor of the servo valve. be. 1... Steering command synchro electric machine, 2... Electric control system, 3... First-order delay control section, 4... Amplifier, 5
... Servo valve, 6 ... Force motor, 7 ... Hydraulic pipe, 8 ... Hydraulic cylinder, 9 ... Piston rod,
10...Crosshead, 11...Joining rod, 12...
...Rudder handle, 13...Rudder.

Claims (1)

[Scope of utility model registration request] It is equipped with a synchro electric machine 1 for steering commands, and a force motor 6 for a servo valve 5 which operates by receiving a signal from the synchro electric machine via an electric control system 2, and supplies pressure oil to a hydraulic cylinder 8 by the operation of the servo valve. In a steering device for supplying a desired steering wheel 13,
A steering system characterized in that a primary delay control section 3 is inserted into the electric control system so that the operating speed of the servo valve does not exceed a certain speed.