JPH0597393A - Auto-tension device in hydraulic crane - Google Patents

Abstract

PURPOSE:To soften the impact load acting on a suspending cable by connecting a multidisc brake with a pump port through the first circuit, connecting a hydraulic motor and the pump port through the third and fourth circuits, and connecting the second and fourth circuits through a relief valve. CONSTITUTION:When a suspending cable taken up by a winch is driven out or taken up in the ordinary case, a portion of the working coil supplied from a pump port is supplied into a multidisc brake 21 through the first solenoid valve 22 from the first circuit A, and the multidisc brake 21 is released, and a hydraulic motor 4 is driven by sending other working oil portion into the hydraulic motor 4 or returning the working oil to an oil port 10 by the second and third circuits B and C, and cable operation is performed. When the suspending cable is driven out or taken up by an autotensin action, the second solenoid valve 24 is operated to supply the working oil into the first and second circuits A and B or the fourth circuit D. Accordingly, the impact load acting on the suspending cable can be softened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tensioning device for a hydraulic crane, and more particularly to an automatic tensioning device for a hydraulic crane which is suitable for hoisting or hanging a small boat on a ship.

[0002]

2. Description of the Related Art There is a hydraulic crane using a hydraulic piston for hoisting a boom and a hydraulic winch as a hoisting device as one of unloading devices mounted on a ship. As an example, as shown in FIG. 6, a tower 3 is mounted on a base 1 mounted on a deck S so that it can be swung by a turning device 2, and a hydraulic motor 4 for operating a winch is mounted on the tower 3.
And a first hydraulic piston 6 for raising the boom 5 are provided, and a second hydraulic piston 7 for raising the boom 5 is further provided.
And a hydraulic piston 8 for boom boom extension and contraction, and these swing device 2, hydraulic motor 4 and hydraulic piston 6 are provided.
8 are hydraulic pumps 1 arranged in pump ports 10, respectively
The hydraulic pressure is supplied from 1 through the switching valves 12a to 12f to operate.

[0003]

In the hydraulic crane, however, there is a problem in hoisting or unloading a small boat from the sea. That is, at sea, there is a relative displacement between the ship and the small boat due to sea conditions, and therefore, the rope and the small boat for hoisting the small boat are subject to impact loads. This is not only extremely dangerous when an operator gets onboard because the engine of the small boat is stopped and the hooks are attached / detached, but there is also a problem that it takes time for the hoisting and unloading operations.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and comprises a boom 5
In the hydraulic crane having the winch driven by the hydraulic piston 6 and the hydraulic motor 4, the multi-plate brake 21 is arranged on the hydraulic motor 4, and the multi-plate brake 21 is provided with the first solenoid valve 22. A second circuit B is connected to the pump port 10 by a circuit A, and the hydraulic motor 4 and the pump port 10 are connected to each other through a second circuit B via a control valve 23 and a third circuit C via the control valve 23 and a second solenoid valve 24. And a fourth circuit having one end connected to the hydraulic motor 4 side of the third circuit C and the other end connected to the pump port 10 side of the third circuit C via the second electromagnetic valve 24. D and the second
The automatic tensioning device in the hydraulic crane is configured so that the circuit B and the fourth circuit D are connected via a relief valve 25.

[0005]

[Operation] In such a configuration, when the hoisting rope wound around the winch is paid out or wound up at normal time, a part of the hydraulic oil sent from the pump port is transferred from the first circuit A to the first solenoid valve 22. The hydraulic fluid is supplied to the multi-plate brake 21 via the hydraulic circuit 4 and released, and other hydraulic oil is sent to the hydraulic motor 4 using the second circuit B and the third circuit C or the pump port 1
This is done by actuating the hydraulic motor 4 by returning to zero. When the automatic tension is applied to draw or wind the suspension line, the second solenoid valve 24 is operated to supply the hydraulic oil to the first circuit A and the second circuit B or the fourth circuit D. Do this as you would.

[0006]

[Embodiment] An embodiment of an automatic tension device in a hydraulic crane according to the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 is a circuit diagram of an automatic tension device in a hydraulic crane according to the present invention. In this figure, the same symbols as those in FIG. 6 indicate the same names.

In FIG. 1 and FIG. 2, 21 is a hydraulic motor 4.
This is a multi-disc brake that brakes
Reference numeral ₁ is connected to the pump port 10 by lines L _{1 to} L _{2 to} L ₃ forming the first circuit A having the first electromagnetic valve 22. In addition, 23 is a control valve and 24 is a second
And 25 is a relief valve. And a second circuit B composed of lines L ₄ ~ control valve 23～L ₅ and hydraulic motor 4 and the pump port 10, the line L ₆ ~ control valve 23 to the line L ₇ ~ second solenoid valve 24 to The pump circuit 10 is connected to the pump port 10 by a third circuit C composed of the line L ₈ and a fourth circuit D composed of the line L ₉ to the second electromagnetic valve 24 to the line L ₁₀ . The second circuit B and the fourth circuit D are connected by a line L ₁₁ having a relief valve 25 on the way.

Further, the control valve 23 is provided with a lever 26, the position of the lever 26 is detected by a limit switch 27, and the limit switch 27 operates the first electromagnetic valve 22. Specifically, when the lever 26 is in the neutral position, the first solenoid valve 22 is non-excited, and the line L ₂ is cut off so that the lines L ₁ and L ₃ communicate with each other as shown in FIG. . Therefore, in this case, the hydraulic oil from the pump port 10 is not supplied to the multi-plate brake 21, so that the multi-plate brake 21 acts by the spring force to brake the hydraulic motor 4. The first solenoid valve 22 is designed to interlock with the second solenoid valve 24 as described later. on the other hand,
The second solenoid valve 24 is operated by a switch (not shown). [Operation during normal feeding] Now, description will be given of a case where the hanging rope is fed in a normal state. First, the lever 26 of the control valve 23 is operated to move the control valve 23 in the direction of arrow a in FIG. As shown in 2, the lines L _{4 to} L ₇ communicate with each other and the lines L _{5 to} L ₆ communicate with each other. At this time, the first solenoid valve 22 also moves in the direction of the arrow b depending on the position of the lever 26, and the line L ₂ and the line L ₁ are connected.

When the hydraulic pump 11 is operated in this way, a part of the hydraulic oil sent from the pump port 10 is supplied from the first circuit A to the multi-plate brake 21 to release it, while Hydraulic fluid is supplied from the second circuit B to the hydraulic motor 4 to drive it. Then, a winch (not shown) is actuated to extend the suspension line. [Operation during normal winding] When winding the suspension cord in the opposite direction to the above-described operation, the lever 26 is operated to operate the control valve 23.
1 is moved in the direction of the arrow a ′ in FIG. 1, the hydraulic circuit shown in FIG. 3 is formed, and hydraulic oil is supplied from the first circuit A to the multi-disc brake 21 to release it, and The hydraulic oil can be supplied to the circuit C and the hydraulic motor 4 can be driven in the opposite direction to the case of FIG. [Operation at the time of extending the automatic tension] Next, a case of operating the automatic tension on the suspension line will be described. First, when the automatic tension is applied to the suspension line and is to be extended, a switch (not shown) is operated to move the second tension. Solenoid valve 24
1 is moved in the direction of arrow C in FIG. 1, the first solenoid valve 22 is also moved in conjunction with this to form a hydraulic circuit as shown in FIG.

That is, the hydraulic oil is supplied from the first circuit A to the multi-disc brake 21 to release it, and the hydraulic oil in the second circuit B and the fourth circuit D is operated by the relief valve 25. Since a predetermined pressure difference is maintained, when an impact load is generated on the suspension rope, the hydraulic oil flows following the impact load. That is,
It is designed to absorb this shock. [Operation at the time of winding the automatic tension] On the other hand, in the case of applying the automatic tension to the suspension rope to wind it in, the switch is operated to move the second solenoid valve 24 in the direction of arrow C, as shown in FIG.
A hydraulic circuit as shown in FIG. 4 is configured to supply hydraulic oil to the hydraulic motor 4 from the fourth circuit D. In this case, the hydraulic pressure of the fourth circuit D rises when an impact load hanged up occurs, and as a result, the relief valve 25 operates and the hydraulic oil in the fourth circuit D flows into the second circuit B. . For this reason, it is possible to measure impact relaxation.

[0011]

As is apparent from the above description, the automatic tension device in the hydraulic crane according to the present invention is
In a hydraulic crane having a winch driven by a hydraulic piston 6 for raising the boom 5 and a hydraulic motor 4, a multi-disc brake 21 is arranged on the hydraulic motor 4, and the multi-disc brake 21 is provided with a first solenoid valve 22. The second circuit B connects the hydraulic motor 4 and the pump port 10 via the control valve 23 and the third circuit via the control valve 23 and the second solenoid valve 24. The circuit C and a fourth one end of which is connected to the hydraulic motor 4 side of the third circuit C and the other end of which is connected to the pump port 10 side of the third circuit C via the second electromagnetic valve 24. Circuit D and the second circuit B and the fourth circuit D are connected via a relief valve 25.

Therefore, since the impact load acting on the suspension line is alleviated only by providing an extremely simple hydraulic circuit, the collision between the small boat and the main ship can be prevented or a small amount can be prevented especially when the small boat is hoisted and hung. When an operator is on board the boat, the safety of the boat can be improved.

[Brief description of drawings]

FIG. 1 is an overall hydraulic circuit diagram of an automatic tension device in a hydraulic crane according to the present invention.

FIG. 2 is a hydraulic circuit diagram during normal feeding.

FIG. 3 is a hydraulic circuit diagram during normal transfer.

FIG. 4 is a hydraulic circuit diagram at the time of automatic tension feeding.

FIG. 5 is a hydraulic circuit diagram at the time of automatic tension feeding.

FIG. 6 is a hydraulic circuit diagram of a conventional hydraulic crane.

[Explanation of symbols]

1 Base 2 Revolving device 3 Tower 4 Hydraulic motor 5 Boom 6, 7, 8 Hydraulic piston 10 Pump port 11 Hydraulic pump 12a-12d Switching valve 21 Multi-plate brake 22 First solenoid valve 23 Control valve 24 Second solenoid valve 25 Relief valve 26 Lever 27 Limit switch

Front page continued (72) Inventor Nobuo Fujiwara 3-1-1 Tam, Tamano-shi, Okayama Mitsui Engineering & Shipbuilding Co., Ltd. Tamano Works

Claims (1)

[Claims] 1. A hydraulic crane having a hydraulic piston for raising and lowering a boom and a winch driven by a hydraulic motor, wherein a multi-disc brake is arranged on the hydraulic motor, and the multi-disc brake is provided with a first solenoid valve. A hydraulic circuit and a pump port connected to the pump port by a circuit, a second circuit passing through the control valve, a third circuit passing through the control valve and the second solenoid valve, and one end of the third circuit. Is connected to the hydraulic motor side and the other end is connected to the fourth circuit via the second electromagnetic valve to the pump port side of the third circuit, and is connected to the second circuit and the fourth circuit. An automatic tension device in a hydraulic crane, characterized in that the circuit of No. 4 is connected via a relief valve.