JPS6212584A - Valve device for controlling rope tension - Google Patents

Abstract

PURPOSE:To achieve tension control by a simple hydraulic pump in a mooring apparatus or the like by providing a valve housing of a valve device with a control port in which a fluid pressure proportional to the rope tension is generated, a pump port and a tank port. CONSTITUTION:A variable delivery pump 6 is controlled in such a manner that, when the pressure at a pump port 5 exceeds a predetermined value,the delivery automatically approaches 0. When the tension of a rope 1 is small, a spool of a valve device 4 is urged by a spring to connect a control port 3 to the pump port 5, so that a hydraulic cylinder 2 is retracted to impart tension to the rope 1. On the other hand, when the tension is large, the spool connects the control port 3 to a tank port 7, so that the cylinder 2 is protruded to reduce the tension of the rope 1. thus, the rope tension can be controlled by a variable delivery pump with a conventional cutoff device, and the value device can be of simple construction.

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.
It is known that the oil pressure applied 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 moves in the maximum direction. 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 well e in the pump control device is automatically switched, leading pressure oil to the hydraulic pump control cylinder f, and tilting in the direction that minimizes the displacement of pump C. change the corner. Pump C continues discharging until the hydraulic pressure corresponding to the predetermined tension is reached, and when the predetermined tension is reached, pressure oil is no longer guided to cylinder f and it stops, so pump C discharges a small amount to maintain the predetermined pressure. I come to do it.

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 switches in the same manner as described above, and the pump C moves further to the negative side of the discharge m from the pump actual discharge stopped state. tilt backwards. With this reverse tilting, the pump C performs a kind of motor action and pumps out the hydraulic oil from the rod side of the hydraulic cylinder b.
causes the rondo 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, which are expensive, and especially variable displacement pumps that have a control range from normal rotation to reverse rotation are extremely expensive. It cannot be avoided that it is special and 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 source. Pump is connected.

When the tension of a rope such as a mooring rope is low, the hydraulic pressure generated in the rod-side chamber 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 is pushed by the spring and moves to connect the control port to the pump port.This leads the pressure oil from the hydraulic pump into the rod-side chamber of the hydraulic cylinder, so the cylinder applies tension to the rope. Immerse yourself in that rondo.

Also, when the rope tension is large, the hydraulic pressure generated in the rod-side chamber of the hydraulic cylinder is large, and the force acting on one end of the spool in the housing is stronger than the spring force on the other end. The spool pushes against the spring and moves to connect 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 discharged into the tank, causing the cylinder to protrude its rond so as to reduce the tension on the rope.

(Example) An example of the present invention will be explained with reference to FIG. 2. (1) is a rope represented as a spring S on which a load W acts, and (2) is a hydraulic pressure attached to the end of the rope (1). indicates a cylinder,
The cylinder (2) is fixed to, for example, a quay wall.

(3) is a control port of a valve device (4) that is connected to a chamber (2a) on the rod side that generates hydraulic pressure according to the tension of the rope (1) of the hydraulic cylinder (2), and (5) is a pump Pump port connected to (6), (7) is connected to tank (8
), and the pump (6) is, for example, a general variable displacement pump with a cut-off device.

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 the valve housing (9), and a sliding plate is formed inside the valve housing (9). A freely movable spool (IO) is provided, and the spool (IG
The pressure of the control port (3) was guided to one end of the valve via the flow path Ov, and a spring was applied to the other end.

(13041a is a spool land, and each spool land is such that the force acting on one end of the spool (11), that is, the force due to the hydraulic pressure generated by the rope (1), is applied to the spring on the other end.
When the force acting on one end of the spool (+1) is weaker than the force of the spring (12+), the control port (3) is connected to the tank port (7) when the force is stronger than the force of the spring (12+). The port (3) is formed to be connected to the pump port (5). (Ie is the spring (121 adjustment screw, (+
7) is the connection path between the spring chamber [phase] and the tank port (7).

Figure 4 shows the cut-off control characteristics of the variable displacement pump (6), and the pump (6) automatically reduces the pump displacement to near zero when the pressure at the pump port (5) exceeds the set pressure. to control.

When the tension of the rope (1) is small, the spool GO of the valve assembly @ (4) is pushed by the spring (1) and connects the control port (3) to the pump port (5), so the hydraulic cylinder (or the rope) 1) to give tension to the O-bu (1).
If the tension in the rope (1) is large, the spool (IO) connects the control port (3) to the tank port (7), so the cylinder (2) protrudes to reduce the tension in 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 housing of the valve device, and a pump port and a tank port are formed in the valve housing 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 the drawing]

FIG. 1 is a pictorial diagram of a conventional example, FIG. 2 is a line diagram of an embodiment of the present invention, FIG. 3 is a sectional view of a specific embodiment of the main part thereof, and FIG. 4 is a diagram of a pump control characteristic curve.

Claims (1)

[Claims] A control port that generates fluid pressure according to rope tension;
A spool with the pressure of the control port acting on one end and a spring force acting on the other end slides inside a valve housing that has a pump port connected to the hydraulic pump and a tank port connected to the tank. 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, and the force acting on the other end of the spool is 1. A rope tension control valve device, characterized in that a spool land is formed which connects the control port to a pump port when the force is greater than the force acting on the rope.