JPH0210069B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a valve device used to control the tension of a rope such as a mooring rope at a constant level.

(Prior Art) Conventionally, for example, in a mooring device, the tension of a mooring rope has been controlled to a constant level by a hydraulic device. A system is known in which the hydraulic pressure to the cylinder b is controlled by a variable displacement piston pump c.

In the case shown in the figure, when no load is applied to the mooring rope a, the pump regulator control piston d in the pump control device is pushed by the spring force and moves, so the pump tilt angle of the pump c is in the maximum direction. The pump discharge amount increases. As a result, the discharge amount of the pump c flows into the rod side of the hydraulic cylinder b and pulls the mooring rope a.
Since the mooring rope a generates tension according to the load, it can be mechanically treated as a spring, but if the rope a continues to be pulled by the cylinder b, the tension will increase and it will break, so the mooring rope can be treated as a spring. When the hydraulic pressure applied to b reaches a predetermined value, the pressure control valve e in the rope control device is automatically switched, leading pressure oil to the hydraulic pump control cylinder f, and pump c
Change the tilt angle in the direction that minimizes the displacement of. The rope c continues to discharge until the hydraulic pressure corresponding to the predetermined tension is reached, and when the predetermined tension is reached, pressure oil is no longer introduced into the cylinder f and the pump c stops pumping, so that the pump c pumps a small amount of fluid to maintain the predetermined pressure. It starts to vomit.

Furthermore, when the tension of the rope a increases and the hydraulic pressure applied to the hydraulic cylinder b exceeds a predetermined value, the pressure control valve e is switched in the same manner as described above, and the pump c is further moved to the negative side of the discharge amount from the state where the actual pump discharge is stopped. tilt backwards. With this reverse tilting, pump c performs a kind of motor action and pumps out the hydraulic oil from the rod side of hydraulic cylinder b, which causes the rod to protrude and relax the tension on the rope.

(Problems to be Solved by the Invention) Conventional devices such as those described above use variable displacement pumps and are therefore expensive.In particular, variable displacement pumps with a control range from normal rotation to reverse rotation are extremely expensive. It is special and inevitably expensive.

An object of the present invention is to provide a valve device for controlling rope tension using an inexpensive device.

(Means for Solving the Problems) In the present invention, a valve housing is provided with a control port that generates fluid pressure according to rope tension, a pump port that is connected to a hydraulic pump, and a tank port that is connected to a tank. A spool, on which the pressure of the control port acts on one end and a spring force acts on the other end, is slidably provided inside the spool, and a force acting on the one end of the spool causes a force acting on the other end. When the force acting on the other end side is more dominant than the force acting on the one end side, connect the control port to the tank port, and connect the control port to the pump port. I tried to form it.

(Function) The control port of the valve housing of the valve device is connected to a hydraulic cylinder to which a rope such as a mooring rope is tied, and the pump port is connected to a hydraulic cylinder used as a gear pump, vane pump, or other general hydraulic power source. Pump is connected.

When the tension of a rope such as a mooring rope is small, the hydraulic pressure generated in the chamber on the rod side of the hydraulic cylinder is low, so the force acting on one end of the spool in the valve housing is weaker than the spring force on the other end. The spool moves under the pressure of the spring and connects the control port to the pump port. This directs pressure oil from the hydraulic pump into the chamber on the rod side of the hydraulic cylinder, so that the cylinder retracts the rod so as to apply tension to the rope.

Also, when the rope tension is large, the hydraulic pressure generated in the rod side chamber of the hydraulic cylinder is large.
When the force acting on one end of the spool in the valve housing is greater than the spring force on the other end, the spool moves against the spring and connects the control port to the tank port. This causes the high pressure in the chamber on the rod side of the hydraulic cylinder to be vented to the tank, causing the cylinder to project its rod to relieve the tension on the rope.

(Example) An example of the present invention will be explained with reference to FIG.
2 is a rope represented as a spring S on which a load W acts, and 2 is a hydraulic cylinder to which the end of the rope 1 is attached, and the cylinder 2 is fixed to a quay, for example. Reference numeral 3 denotes a chamber 2 on the rod side in which hydraulic pressure corresponding to the tension of the rope 1 of the hydraulic cylinder 2 is generated.
a, a control port of the valve device 4 connected to a, 5 a pump port connected to a pump 6, 7 a tank port connected to a tank 8, and the pump 6
For example, a general variable displacement pump with a cut-off device is used.

The specific structure of the valve device 4 is, for example, as shown in the third figure, in which a control port 3, a pump port 5, and a tank port 7 are formed in a valve housing 9, and a spool 10 is slidably provided inside. 1
The pressure of the control port 3 is guided to one end of the 0 through the flow path 11, and the spring 12 is applied to the other end.

Reference numerals 13, 14, and 15 denote spool lands, and each spool land is controlled when the force acting on one end of the spool 10, that is, the force due to the hydraulic pressure generated by the rope 1, is superior to the force of the spring 12 on the other end. The port 3 is connected to the tank port 7, and when the force acting on one end of the spool 10 is weaker than the force of the spring 12, the control port 3 is connected to the pump port 5. 16 is an adjustment screw for the spring 12, and 17 is a connection path between the spring chamber 18 and the tank port 7.

FIG. 4 shows the cut-off control characteristics of the variable displacement pump 6, and the pump 6 automatically controls the pump displacement to be close to zero when the pressure at the pump port 5 exceeds the set pressure.

When the tension of the rope 1 is small, the spool 10 of the valve device 4 is pushed by the spring 12 and connects the control port 3 to the pump port 5, so that the hydraulic cylinder 2 is retracted to apply tension to the rope 1, and the tension of the rope 1 is reduced. If is large, the spool 10 connects the control port 3 to the tank port 7, and the cylinder 2 protrudes to reduce the tension on the rope 1. In this case, the pump 6 may be an inexpensive one used as a hydraulic power source, such as a normal gear pump.

(Effects of the Invention) According to the present invention, a control port, a pump port, and a tank port are formed in the valve casing of the valve device, and a pump port and a tank port are formed in the valve casing of the valve device. We have formed a spool land that selectively connects the control port to the pump port or tank port depending on the strength of the force acting on one end of the spool and the force acting on the other end of the spool. Since the tension can be controlled and the valve device has a simple configuration and can be manufactured at low cost, the entire tension control device can be made inexpensive.

[Brief explanation of drawings]

Fig. 1 is a diagram of a conventional example, Fig. 2 is a diagram of an embodiment of the present invention, Fig. 3 is a sectional view of a specific embodiment of the main part, and Fig. 4 is a pump control characteristic curve diagram. . 1... Rope, 3... Control port, 5... Pump port, 6... Pump, 7... Tank port,
9... Valve case, 10... Spool, 12... Spring,
13, 14, 15...Spool Land.

Claims (1)

[Claims] 1. The pressure of the control port acts on one end of the valve housing, which has a control port that generates fluid pressure according to the rope tension, a pump port connected to the hydraulic pump, and a tank port connected to the tank. A spool with a spring force applied to the other end is slidably provided, and when the force acting on the one end of the spool is greater than the force acting on the other end, the control port is connected to the tank port. A rope tension control valve device comprising a spool land that connects the control port to a pump port when the force acting on the other end is greater than the force acting on the one end. .