JP2604292B2 - Auto tension device for hydraulic crane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auto-tension device for a hydraulic crane, and more particularly to an auto-tension device for a hydraulic crane suitable for lifting a small boat from the sea or hanging it off the sea.

[0002]

2. Description of the Related Art As one of unloading devices mounted on a ship, there is a hydraulic crane using a hydraulic piston for raising and lowering a boom and a hydraulic winch as a hoisting device. As an example, as shown in FIG. 6, a tower 3 is mounted on a base 1 mounted on a deck S so that the tower 3 can be turned 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 elevating the boom 5, and a second hydraulic piston 7 for elevating the boom 5 further
And a hydraulic piston 8 for extending and retracting the boom, and these turning device 2, hydraulic motor 4 and hydraulic piston 6 are provided.
8 are hydraulic pumps 1 arranged in the pump port 10, respectively.
The hydraulic pressure is supplied from 1 via the switching valves 12a to 12f to operate.

[0003]

In the above-mentioned hydraulic crane, there is a problem when the boat is lifted from the sea or lifted off the sea. That is, in a normal sea, there is a relative displacement between the ship and the small boat due to sea conditions, and therefore, an impact load is applied to the ropes for lifting the small boat and the small boat. This is not only extremely dangerous when an operator gets on the boat for starting / stopping the engine of the small boat or attaching / detaching the hanging hooks, but also has a problem that the lifting and unloading work takes time.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has been made in consideration of the problems described above.
In a hydraulic crane having a hydraulic piston 6 and a winch driven by a hydraulic motor 4, a multi-plate brake 21 is disposed on the hydraulic motor 4, and the multi-plate brake 21 is connected to a first solenoid valve 22 having a first solenoid valve 22. The hydraulic motor 4 and the pump port 10 are connected to the pump port 10 via a circuit A, and a second circuit B via the control valve 23 and a third circuit C via the control valve 23 and the 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 second circuit B via the second solenoid valve 24. D and the second
This is an auto-tension device in a hydraulic crane configured to connect the circuit B and the fourth circuit D via a relief valve 25.

[0005]

In this configuration, when the lifting cable wound around the winch is normally extended or wound, a part of the hydraulic oil sent from the pump port is transferred from the first circuit A to the first solenoid valve 22. And releases it to the multi-plate brake 21 and sends another hydraulic oil to the hydraulic motor 4 using the second circuit B and the third circuit C or to the pump port 1.
This is done by activating the hydraulic motor 4 by returning it to zero. Then, when the suspension cable is extended or retracted by applying the auto tension, 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. You do this as you would.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic tensioning device in a hydraulic crane according to the present invention will be described below with reference to FIGS. FIG. 1 is a circuit diagram of an auto-tension device in a hydraulic crane according to the present invention. In FIG. 1, the same reference numerals as in FIG. 6 denote the same names.

In FIGS. 1 and 2, reference numeral 21 denotes a hydraulic motor 4
This is a multi-plate brake that brakes
1 is connected to the pump port 10 via lines L _{1 to} L _{2 to} L ₃ constituting a first circuit A having a first solenoid valve 22. 23 is a control valve, and 24 is a second control valve.
Is a relief valve, 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 third and circuit C consisting of a line L _8, is connected to the pump port 10 by the fourth circuit D composed of lines L ₉ ~ second solenoid valve 24 to the line L ₁₀ of. And a second circuit B and the fourth circuit D are in communication with the 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 solenoid valve 22. Specifically, when the lever 26 is in the neutral position,
When the switch for operation is off, the first solenoid valve 2
2 becomes non-excited, the line L ₂ as shown in FIG. 1 is cut off the line L ₁ and L ₃ are in communication with.
Accordingly, in this case, the hydraulic oil from the pump port 10 is not supplied to the multi-plate brake 21, and the multi-plate brake 21 acts by the spring force to brake the hydraulic motor 4. The first solenoid valve 22 is connected to the lever 2
In addition to the operation of the limit switch 27, the second solenoid valve 24 operates in conjunction with the second solenoid valve 24 as described later. On the other hand, the second solenoid valve 24 is provided with an automatic
It is operated by a switch for activating the station . [Operation at the time of normal extension] Now, the case of extending the suspension line in the normal state will be described.
First, the line L ₅ ~L ₆ with the line L ₄ ~L ₇ As is moved in the direction of arrow a shown in FIG. 2 in FIG. 1 the control valve 23 by operating the lever 26 of the control valve 23 is communicated with Communicate. The first solenoid valve 22 by the position of the time the lever 26 is also moved line L ₂ and the line L ₁ is connected to the direction of arrow b.

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 multiple disc brake 21 to release it, Is supplied from the second circuit B to the hydraulic motor 4 to drive it. Then, a winch (not shown) is operated to extend the suspension cable. [Operation at the time of normal winding] Contrary to the above-mentioned operation, when winding the suspension cable, the lever 26 is operated to move the control valve 23 in the direction of arrow a 'in FIG. A circuit is formed, and the hydraulic oil is supplied from the first circuit A to the multi-plate brake 21 to release it, and the hydraulic oil is supplied to the third circuit C so that the hydraulic motor 4 is switched to the case shown in FIG. Can be driven in the opposite direction to wind the sling. [Operation at the time of extending the auto tension] Next, the case of operating the auto tension on the suspension line will be described. First, when the auto tension is applied to the suspension line and the suspension is extended , the lever of the control valve 23 is moved.
-26 to the neutral position, the limit switch 27
What is first solenoid valve is a non-excited, not shown O
When the second solenoid valve 24 is moved in the direction of arrow d in FIG. 1 by operating the switch for actuating the tension, the first solenoid valve 22 is also moved in the direction of arrow b in conjunction with this operation.
The hydraulic circuit as shown in FIG.

That is, hydraulic oil is supplied from the first circuit A to the multi-plate brake 21 and released, and the hydraulic oil in the second circuit B and the fourth circuit D is subjected to a large impact on the suspension cable.
When a load is generated, the hydraulic motor 4 is extended following the load.
Try to rotate to the side, the hydraulic pressure of the line L ₉ of the fourth circuit D
Increasingly, greater than the hydraulic pressure of the line L ₄ of the second circuit B
And the pressure difference becomes larger than the set value of the relief valve.
Then, the relief valve 25 operates as shown in FIG.
Line hydraulic oil line L ₉ of the circuit D of the second circuit B
Since flows into the L _4, the hydraulic motor 4 is rotated, the slings are Repetitive
Will be issued. That is, the impact is reduced. Then, the impact load that starts to extend at the time of auto tension
The magnitude of the heavy tension is adjusted by the set pressure of the relief valve.
Can be adjusted. [Operation at the time of auto-tension winding] On the other hand, when the auto-tension is applied to the sling line, the lever 26 of the control valve 23 is set to the neutral position.
Then, depending on the limit switch 27, the first solenoid valve
Operates the switch for auto-tension operation to move the second solenoid valve 24 in the direction of the arrow d while keeping the non-excitation state.
Thus , a hydraulic circuit as shown in FIG. 5 is configured to supply hydraulic oil to the hydraulic motor 4 from the fourth circuit D , and the hydraulic motor 4 is rotated.
And retract the sling. In this case, the impact load
Occurs, the rotational force of the hydraulic motor 4 in the retraction direction wins.
Keep running while you are. And, the retraction of the hydraulic motor 4
Of hydraulic motor 4 by impact load
Rotational force of directionally is winning, but the line L ₉ and the line L
The pressure difference between the hydraulic oils of ₄ is smaller than the set value of the relief valve 25
In this case, the hydraulic motor stops because the hydraulic oil does not flow.
State, the impact load further increases and the pressure difference
When it exceeds the set value of the safety valve 25, it is extended as described above.
Do. Therefore, it is possible to reduce the impact. In addition, feeding and feeding by auto tension
During operation, the lever 26 of the control valve 23 is
When manually operated from the upright position, it is for normal feeding or normal winding
The part of the circuit is additionally formed and the auto tension work
Manual operation can be performed prior to the circuit.

[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 hydraulic piston 6 for raising and lowering a boom 5 and a winch driven by a hydraulic motor 4, a multi-plate brake 21 is disposed on the hydraulic motor 4, and the multi-plate brake 21 is connected to a first The hydraulic motor 4 and the pump port 10 are connected to the pump port 10 by the first circuit A, the second circuit B is connected to the pump port 10 via the control valve 23, and the third circuit is connected to the pump port 10 via the control valve 23 and the second solenoid valve 24. A fourth circuit C 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 second circuit B via the second solenoid valve 24; , And the second circuit B and the fourth circuit D are connected via a relief valve 25.

Accordingly, the impact load acting on the suspension cable is reduced only by providing a very simple hydraulic circuit. Therefore, particularly when a small boat is lifted and unloaded on a ship, it is possible to prevent collision between the small boat and the ship and / or to reduce the size of the small boat. When a worker gets on a boat, the safety of the boat can be improved.

[Brief description of the 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 at the time of normal retraction.

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 auto tensioning.

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

[Explanation of symbols]

Reference Signs List 1 base 2 turning device 3 tower 4 hydraulic motor 5 boom 6, 7, 8 hydraulic piston 10 pump port 11 hydraulic pump 12a to 12d switching valve 21 multi-plate brake 22 first electromagnetic valve 23 control valve 24 second electromagnetic valve 25 Relief valve 26 Lever 27 Limit switch

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuo Fujiwara 3-1-1, Tamano, Tamano-shi, Okayama Pref.

Claims (1)

(57) [Claims] In a hydraulic crane having a hydraulic piston for raising a boom and a winch driven by a hydraulic motor, a multi-plate brake is arranged on the hydraulic motor, and the multi-plate brake is connected to a first solenoid valve having a first solenoid valve. A second circuit through a control valve, a third circuit through the control valve and a second solenoid valve, and one end connected to the third circuit by a hydraulic circuit and the pump port. The other end is connected to a fourth circuit connected to the hydraulic motor side and the other end is connected to the pump port side of the second circuit via the second solenoid valve, and the second circuit is connected to the fourth circuit. An automatic tension device for a hydraulic crane, wherein the automatic tension device is configured to be connected to the circuit of (4) via a relief valve.