JP3119903B2 - Hydraulic cylinder hydraulic circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic circuit for a hydraulic cylinder used as an actuator or the like in a ship or a vehicle.

[0002]

2. Description of the Related Art A conventional hydraulic circuit of a hydraulic cylinder for moving an outboard motor of a ship left and right is shown in FIG.
A hydraulic cylinder 100 having two oil chambers S1 and S2 defined by slidably fitting a piston 102 in the piston 01 and a rod 103 fixed to one side of the piston 102 is provided. Then, hydraulic oil is supplied to the hydraulic cylinder 100 /
The hydraulic circuit that discharges supplies hydraulic oil discharged from a reversible hydraulic pump 106 that is rotationally driven by a motor 105 to a hydraulic cylinder 100 via a counter valve 107.

In this hydraulic circuit, a hydraulic pump 10
6 is rotated to supply the operating oil to the chamber 108 side of the counter valve 107, so that the check valves 110, 11
1 is opened, the hydraulic oil in the oil chamber S1 of the hydraulic cylinder 100 flows in through the check valve 110, and the hydraulic oil in the oil chamber S2 returns to the hydraulic pump 106 through the check valve 111. Elongates. Further, the hydraulic pump 106 is driven to rotate in the opposite direction to the above, and the counter valve 1 is rotated.
By supplying the operating oil to the chamber 109 side of 07, the check valves 111 and 110 are opened, and the check valves 11 and 110 are opened.
Hydraulic oil flows into the oil chamber S2 of the hydraulic cylinder 100 via the first valve 1 and the hydraulic oil in the oil chamber S1 returns to the hydraulic pump 106 via the check valve 110, so that the rod 103 contracts.

[0004]

However, in the hydraulic circuit of the hydraulic cylinder as described above, when the discharge amount of the hydraulic pump 106 is constant, the hydraulic cylinder 100
When hydraulic oil is supplied into the oil chamber S1, the entire cross-sectional area of the piston becomes the pressure receiving area, whereas when hydraulic oil is supplied into the oil chamber S2, the cross-sectional area of the piston 102 and the rod 1
03 is the pressure receiving area, the rod 103
When the outboard motor is moved up and down, the speed of ascending and descending is different. There is a difference between left and right.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a piston which is slidably fitted in a cylinder.
The rod is fixed to one side of the piston and the inside of the cylinder is locked.
Between the piston side oil chamber and the non-rod side oil chamber.
The difference between the cross-sectional area and the cross-sectional area of the rod is the cross-sectional area of the rod.
Reversible for hydraulic cylinders formed equal
In a hydraulic circuit that supplies hydraulic oil by a hydraulic pump
Thus, each discharge port of the hydraulic pump and the lock of the hydraulic cylinder
The oil passage connecting the oil chamber on the
Switching the oil chamber to which hydraulic oil is supplied according to the discharge direction
The counter oil valve and the rod side oil chamber
From the pump to the oil passage connecting the side oil chamber,
When hydraulic fluid is discharged to the
Whether the rod side oil chamber and the non-rod side oil chamber are shut off as pressure
Hydraulic switching valve to switch from
In the oil passage connecting the side oil chamber and the hydraulic pump,
The rod side oil chamber and the non-rod side oil chamber are connected by the exchange valve
Prevents hydraulic oil from returning to the pump from each oil chamber when
A check valve is provided.

[0006]

[Function] Hydraulic oil is supplied depending on the discharge direction of the pump.
Oil chamber with rod side oil chamber or counter rod oil with counter valve
When switching to the oil chamber and supplying hydraulic oil to the oil chamber on the opposite side
By connecting two oil chambers with a hydraulic switching valve ,
The two oil chambers in the same pressure, the hydraulic oil in the rod side <br/> oil chamber so as fed to the counter-rod-side oil chamber with the extension of the rod. Since the pressure receiving area at that time is equal to the cross-sectional area of the rod, the difference in the moving speed of the rod can be reduced by making the difference between the cross-sectional area of the piston and the cross-sectional area of the rod close to the cross-sectional area of the rod. Also, check valve
Prevents hydraulic fluid in each oil chamber from returning to the pump.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a schematic plan view of a ship provided with a hydraulic cylinder to which the present invention is applied, and FIG. 2 is a hydraulic circuit diagram of the hydraulic cylinder.

A steering handle 2 is provided substantially at the center of the hull 1, and a transam unit 3 is provided at the rear of the hull 1.
The propulsion unit 4 is mounted so as to be able to swing in a horizontal plane. Then, the movement of the steering handle 2 is transmitted to a steering cable 6 via a rack and pinion mechanism 5, and the movement of the steering cable 6 is transmitted to a hydraulic cylinder 7 which is an actuator, thereby performing steering.

The hydraulic cylinder 7 has a piston 9 slidably fitted in the cylinder 8 to define two oil chambers, an oil chamber S1 and an oil chamber S2. A rod 10 that is inserted and connects the distal end to the arm 4a of the propulsion unit 4 is fixed.

In a hydraulic circuit for supplying hydraulic oil to the hydraulic cylinder 7, each discharge port of a reversible hydraulic pump 12 driven to rotate by a motor 11 is connected to a tank 15 via check valves 13 and 14. Further, each discharge port of the hydraulic pump 12 is connected to a left chamber 17 and a right chamber 18 defined by a spool 16 a of the counter valve 16. The left chamber 17 of the counter valve 16 is directly connected to an oil chamber S1 of the hydraulic cylinder 7 via a check valve 19, and the right chamber 18 is connected to an oil chamber S2 of the hydraulic cylinder 7 via a check valve 20 and a check valve 21. Connected. Also, counter valve 1
The left chamber 17 and the right chamber 18 of 6 are relief valves 22, 23.
Is connected to the tank 15.

An oil chamber S1 in which the rod 10 of the hydraulic cylinder 7 is not inserted and an oil chamber S2 in which the rod 10 is inserted are connected via a switching valve 25. The switching valve 25 is provided by the hydraulic pump 12 and the counter valve 1.
The discharge pressure when the hydraulic oil is discharged to the left chamber 17 of FIG. 6 is used as the pilot pressure to switch from the cutoff portion 25a to the communication portion 25b, thereby connecting the oil chamber S1 and the oil chamber S2.

The oil chambers S1 and S2 of the hydraulic cylinder 7
Is connected to the tank 15 via a manual valve 26. When the manual valve 26 becomes inoperable due to a failure or the like, each of the oil chambers S1, S2 and the tank 15
It is for communicating with.

The operation of the hydraulic circuit of the hydraulic cylinder configured as described above will be described. First, the hydraulic pump 12 is rotationally driven by the motor 11 so that the hydraulic oil discharged from the hydraulic pump 12 is supplied to the right chamber 1 of the counter valve 16.
8, the check valve 20 is opened by this discharge pressure, and the spool 16a moves to check valve 19
Is opened. At this time, the switching valve 25 is connected to the shutoff unit 2
At 5a, the space between the oil chambers S1 and S2 is shut off.

Thus, the hydraulic oil from the hydraulic pump 12 is supplied to the right chamber 18 of the counter valve 16 and the check valve 20.
And the oil chamber S2 of the hydraulic cylinder 7 via the check valve 21
And the hydraulic oil in the oil chamber S1 of the hydraulic cylinder 7 returns to the hydraulic pump 12 via the check valve 19 of the counter valve 16 and the left chamber 17, so that the rod 10 of the hydraulic cylinder 7 moves in the direction of arrow B. Moving. At this time, the pressure receiving area of the hydraulic cylinder 7 is the difference between the cross-sectional area of the piston 9 and the cross-sectional area of the rod 10.

On the other hand, when the hydraulic pump 12 is rotated in the opposite direction to the above and the hydraulic oil discharged from the hydraulic pump 12 is sent to the left chamber 17 of the counter valve 16, the check valve 19 is opened by this discharge pressure. Then, the spool 16a moves and the check valve 20 is opened. At this time, when the discharge hydraulic oil flows into the left chamber 17 of the counter valve 16, a pilot pressure is applied to the switching valve 25, and the communication portion 25b is interposed in the oil passage so that the oil chamber S of the hydraulic cylinder 7 is opened.
1 and the oil chamber S2.

As a result, the operating oil from the hydraulic pump 12 is supplied to the left chamber 17 of the counter valve 16 and the check valve 19.
Through the communication section 25b of the switching valve 25 and the oil chambers S1 and S2 of the hydraulic cylinder 7 communicate with each other, and the same pressure is obtained. Hydraulic oil in S2 is in oil chamber S1
Sent inside. At this time, the check valve 21 shuts off the connection between the oil chamber S2 and the hydraulic pump 12. The pressure receiving area at this time is the cross-sectional area of the piston 9 on the oil chamber S1 side, and the difference between the cross-sectional area of the piston 9 and the cross-sectional area of the rod 10 on the oil chamber S2 side. The rod 10 moves in the direction indicated by the arrow C in FIG.

Accordingly, the pressure receiving area when moving the rod 10 in the direction of arrow B (the difference between the cross-sectional area of the piston 9 and the cross-sectional area of the rod 10) and the pressure receiving area when moving the rod 10 in the direction of arrow C (Cross-sectional area of the rod 10), the speed of each movement direction of the rod 10 can be made closer to the same .

Thus , in the case of a double rod type
Without increasing the overall length of the hydraulic cylinder as in
Movement speed in each direction can be equalized.
You.

[0019]

According to the present invention as described above,
Counter valve and hydraulic switching valve provided in hydraulic circuit
When the hydraulic oil is supplied to the oil chamber on the side where the rod of the hydraulic cylinder is not inserted, the two oil chambers of the hydraulic cylinder communicate with each other. , The moving speed in each direction can be made equal, the speed at the time of extension can be increased, and the discharge amount can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a ship provided with a hydraulic cylinder to which the present invention is applied.

FIG. 2 is a hydraulic circuit diagram of the hydraulic cylinder.

FIG. 3 is a hydraulic circuit diagram of a conventional hydraulic cylinder.

[Explanation of symbols]

2 ... steering wheel, 6 ... steering cable, 7 ... hydraulic cylinder, 8 ... cylinder, 9 ... piston,
10 rod, 12 hydraulic pump, 16 counter valve, 21 check valve, 25 switching valve , S1
Rod side oil chamber (oil chamber), S2 ... rod side oil chamber (oil chamber) .

Claims (1)

(57) [Claims] 1. A piston is slidably fitted in a cylinder, and a rod is fixed to one side of the piston.
Are defined in a rod-side oil chamber and a non-rod-side oil chamber.
The difference between the cross-sectional area of the ton and the cross-sectional area of the rod is
In a hydraulic circuit for supplying hydraulic oil by a reversible hydraulic pump to a hydraulic cylinder formed to have an equal area, each discharge port of the hydraulic pump and the hydraulic cylinder
The oil passage connecting the rod-side and non-rod-side oil chambers
Turn off the oil chamber to which hydraulic oil is supplied according to the discharge direction of the pump.
Replace the counter valve with the oil chamber on the rod side
To the oil passage connecting the oil chamber on the
When discharging hydraulic oil to the oil chamber, the discharge pressure
The rod side oil chamber and the non-rod side oil chamber are shut off as the cut pressure
Hydraulic switching valve for switching from the normal state to the communicating state
The hydraulic line connecting the oil chamber on the
The rod-side oil chamber and the non-rod-side oil chamber are separated by a switching valve.
Hydraulic circuit of the hydraulic cylinder, wherein the hydraulic oil only set a check valve to prevent the return to the pump from the oil chamber when communicated.