JPH10330084A - Counter weight attaching/detaching device of crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attach/detach a counter weight by one worker by providing the operation circuit of a control valve for controlling a hydraulic motor and hydraulic cylinder drive and also a portable operation device for adding the remote operation signal for operating the control valve to the operation circuit. SOLUTION: A portable operation device 41 is connected to the operation circuit of a control valve loaded on an upper structure 2 by a cable 45 and operates the hydraulic motor 26 and hydraulic cylinders 15a, 15b of a winch 13. By that a worker holds the portable operation device 41 and operates the operation switch of the portable operation device 41 while looking at an A frame 5 and counter weight 17 on the earth or an upper turning body 2, the control valve can be switched through a pilot valve and the control valve of hydraulic cylinders 15a, 15b can be operated. Thereby, the attaching/detaching work of the counter weight can be carried out by one worker safely and surely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane counterweight attachment / detachment device for attaching / detaching a counterweight placed on an upper swing body using a hydraulic device.

[0002]

2. Description of the Related Art Conventionally, when changing the lifting capacity or changing the boom length of a crane, a counterweight mounted on a rear portion of an upper revolving structure is added or removed to balance the whole. . When attaching and detaching such a counterweight, as disclosed in Japanese Utility Model Laid-Open Publication No. 6-6380, an A frame (also referred to as a gantry) installed at the rear of the upper swing body of the crane, The counterweight is attached and detached using the hydraulic cylinder attached to the frame.

[0003] That is, the A frame is assembled on the upper revolving structure so that the front leg and the rear leg form a triangle, and the rear leg is combined with the inner and outer members so as to be able to expand and contract. It is configured to be fixed so that it cannot expand and contract. At the top of the A-frame, a sheave block for attaching a boom hoisting rope wound around a boom hoisting winch mounted on the upper rotating body to a sheave block called a bridle is attached. Are connected by a pendant rope, and the boom is supported by the pendant rope.

When the counterweight placed on the ground is mounted on the rear part of the upper revolving structure, the boom and the upper revolving structure are connected to each other by a rod called a back stop so as not to bend back, and the A frame is used. With the rear leg stretchable, tilt the A frame backward, extend the hydraulic cylinder that hangs down from the top of the A frame, connect the connection of the counterweight to its lower end, and contract the hydraulic cylinder to release the counterweight. By lifting and operating the boom hoisting winch in the winding direction of the boom hoisting rope, the A frame is rotated in the erecting direction while supporting the A frame by the boom, and the counterweight reaches the mounting position of the upper rotating body. When the winch is stopped, the hydraulic cylinder is extended and the counterweight is lowered onto the upper swing body. When the counterweight on the upper revolving structure is lowered onto the ground, the procedure is reversed.

Conventionally, such attachment and detachment of the counterweight is conventionally performed in a cab mounted on a front portion of the upper revolving unit in a cab.
The operator performs the operation by operating the hydraulic cylinder for attaching and detaching the boom hoisting winch and the counterweight while receiving a signal from a worker near the work location.

[0006]

In the conventional counterweight attaching / detaching apparatus for a crane constructed as described above, an operator in an operator's cab and an operator who is on the ground or on an upper revolving unit and performs a slinging operation or the like. Two or more people are required. In addition, every operation requires a signal between operators, and errors are likely to occur. Further, there is a possibility that the boom, the A frame and the like may be damaged due to excessive winding of the boom hoisting rope by the boom hoisting winch.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a counterweight attaching / detaching apparatus for a crane which allows one worker to attach / detach a counterweight.

Another object of the present invention is to provide a crane counterweight attaching / detaching apparatus capable of preventing the boom or A frame from being damaged due to excessive winding of the boom hoisting rope by the boom hoisting winch. I do.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a crane having an A-frame mounted on an upper revolving structure by a hydraulic device so as to be able to move up and down, and a hydraulic cylinder for attaching and detaching a counterweight connected to the top of the A-frame. In the counterweight attaching / detaching apparatus, an operation circuit that can be switched by an electric signal is provided as an operation circuit of a control valve that performs drive control of the hydraulic motor and the hydraulic cylinder, and the operation circuit includes a remote control for operating the control valve. A portable operation device for applying a signal is provided (claim 1).

Further, the present invention detects when the rising angle of the A frame exceeds a predetermined value, and stops the rising operation of the A frame by the hydraulic device.
A frame rising angle limiting means is provided (claim 2).

[0011]

According to the first aspect of the present invention, a worker operates the portable operating device on the ground or on the upper revolving unit, thereby visually recognizing the A frame, the counterweight, etc., and turning the upper or lower unit in a wired or wireless manner. An electric signal is sent to an operation circuit on the body, and in the operation circuit, the hydraulic device such as a hydraulic motor of a boom hoisting winch and a control valve of a hydraulic cylinder for attaching / detaching a counterweight are switched by the operation signal, whereby the hydraulic device Performs cylinder drive control. Therefore, one worker can attach and detach the counterweight.

In the second aspect, since the rising angle of the A frame is restricted, it is possible to prevent the A frame and the boom from being damaged due to excessive winding of the boom hoisting rope.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a crane counter weight attaching / detaching apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a crane showing an embodiment of a counterweight attaching / detaching apparatus according to the present invention. As shown in FIG.
The upper revolving unit 2 is installed on the lower traveling unit 1 via a revolving unit 3. A boom 4 is attached to the upper swing body 2 so as to be able to move up and down. Reference numeral 5 denotes an A frame installed at the rear of the upper revolving unit 2, and the A frame 5 includes a front leg 5a and a rear leg 5b.
Are assembled so as to form a triangle, the lower end of each is pinned to the upper swing body 2, and the upper end is connected by a rod 14. The rear leg 5b is configured to be extendable and contractible and to be inextensibly fixed by the pin 7 or the like in the extended state shown by the two-dot chain line A.

A boom hoisting winch 1 is provided on the upper swing body 2.
3, a sheave block 12 is attached to a rod 14 at the top of the A frame 5, and the winch 13
A boom hoisting rope 10 wound around the bridge is wrapped around the bridle 11 and the sheave block 12, and the
1 and the boom 4 are connected by a pendant rope 9, and the boom 4 is supported by the pendant rope 9 and the boom hoisting rope 10.

Reference numeral 6 denotes a backstop which connects the back surface of the boom 4 and the upper swing body 2 and prevents the boom 4 from tilting backward by a predetermined amount or more. By being connected by the pin 8, the boom 4 is connected to the upper swing body 2 so as not to be undulated.

A hydraulic cylinder 15 is attached to the rod 14 at the top of the A-frame 5 for attaching and detaching a counterweight 17.
a and 15b are connected at one end.

Reference numeral 41 denotes the hydraulic motor 26 of the winch 13
(See FIG. 2A) and the hydraulic cylinders 15a, 15b
, Which is connected to an operation circuit of a control valve mounted on the upper swing body 2 by a cable 45.

In this crane, the A frame 5 is erected at the position shown by the two-dot chain line A, and the backstop 6 is set in a retractable state without inserting the pin 8 and the winch 1
The boom 4 can be raised and lowered by operating and operating the boom lifting and lowering rope 10.

When mounting the counterweight 17 on the mounting table 18 at the rear of the upper swing body 2, the pin 8 is inserted into the backstop 6 to fix the boom 4 so that it cannot be raised or lowered.
The A frame 5 is connected to a counter weight 17 placed on the ground via a suspension ring 16 with the rods of the hydraulic cylinders 15a and 15b in a state of being tilted rearward as shown by a two-dot chain line C. When the boom hoisting rope 10 is wound up by the winch 13 in this state, the A frame 5 stands up, and as shown by the solid line B, the counter weight 17
When the vehicle reaches the position on the mounting table 18 to be mounted, the winch 13 is stopped, and then the hydraulic cylinders 15a and 15b are extended to lower the counterweight 17 onto the mounting table 18.

FIG. 2A is a hydraulic circuit for driving the above-described winch 13, and FIG. 2B is a hydraulic circuit for driving the hydraulic cylinder 15a.
15b is a hydraulic circuit that drives 15b. In FIG. 2A, reference numeral 26 denotes a hydraulic motor of the winch 13, reference numeral 24 denotes a control valve thereof, and reference numeral 25 denotes a hydraulic pump mounted on the upper swing body 2, which supplies pressure oil to the hydraulic motor 26 of the winch. .

Reference numeral 21 denotes a pilot hydraulic pump for supplying pilot pressure oil such as a control valve 24. The pilot hydraulic pump 21 has a manual operation lever 31 conventionally installed in the cab 2a in the discharge line of the pilot hydraulic pump 21. A pilot valve 22 is provided, and an electromagnetically operated pilot valve 42 that is switched by the portable operation device 41 is provided in parallel with the pilot valve 22, and the secondary side pipeline of the pilot valves 22 and 42 is provided. The operation chamber 2 of the control valve 24 of the hydraulic motor 26 of the winch 13 via the shuttle valve 46 and the electromagnetic valve 23 for automatically stopping overload.
4a, 24b.

As shown in FIG. 2B, the pilot hydraulic pump 21 is used as a drive hydraulic source for the hydraulic cylinders 15a and 15b for attaching and detaching the counterweight 17, and the control valves 29 and 30 serve as solenoids 29.
An electromagnetically operated control valve having a, 29b and 30a, 30b is incorporated as a set of control valves 27. In addition, an electromagnetically operated on-off valve 28 having a solenoid 28a for enabling the hydraulic cylinders 15a and 15b to be operable is provided.

FIG. 3 shows the portable operating device 41, the on-off valve 28, and the pilot valve 4 of the control valve 24.
FIG. 3 is a circuit diagram showing a connection relationship between the portable operating device 41 and a pilot valve 29, 30;
Each of the operation switches 41a to 41g includes a solenoid 28a for the on-off valve 28, solenoids 42a and 42b for the pilot valve 42, and a control for the hydraulic cylinder 15a installed on the right side of the upper swing body 2. The solenoids 29a and 29b of the valve 29 and the solenoid 30 of the control valve 30 for the left hydraulic cylinder 15b
a, 30b. The operation switch 4
When 1a is turned on, the on-off valve 28 is switched from the right position to the left position, so that the communication state of the pilot-side hydraulic pump 21 with the discharge-side conduit to the tank is switched to the cut-off state, and the hydraulic cylinders 15a and 15b are turned off. It becomes operable by the pressure oil from the pilot hydraulic pump 21. Also,
When the operation switch 41b or 41c is operated, the corresponding solenoid 42a or 42b is energized, and the pilot valve 42 is switched to the left or right position, whereby the control valve 24 is switched and the hydraulic motor 26
Operates in the winding direction or the unwinding direction. As a result, the A frame 5 operates in the upward or downward direction.
By operating the operation switches 41d to 41g, the solenoids 29a, 29b, 30a or 30b are energized, the valves 29 and 30 are switched, and the hydraulic cylinders 15a and 15b contract or extend.

In FIG. 3, the circuit on the rising side of the A frame 5 of the pilot valve 42 detects when the rising angle of the A frame 5 exceeds a predetermined value, and detects the rise angle of the boom up / down winch 13. A limit switch 44 for stopping the hoisting operation of the A frame 5 by stopping the winding of the boom hoisting rope 10 is inserted.

As shown in FIG. 4, the upper revolving unit 2 is mounted on a bracket 46 for mounting a front leg 5a, and the front leg 5a is rotatably mounted on the bracket 46 by a pin 43. The limit switch 44 is connected to the bracket 46
The limit switch 44 is switched by a striker 47 attached to the root end of the front leg 5a to turn off the circuit between the operation switch 41b and the A frame raising solenoid 42a. The limit switch 44 starts the A frame 5,
In FIG. 1, the position shown by the two-dot chain line A, that is, the position where the A frame 5 is fixed by the insertion of the pin 7 exceeds
As shown by the two-dot chain line D, a stopper (not shown) for preventing the inner and outer members constituting the rear leg 5b from coming out acts on the boom 4 and the A frame 5 at a position where an excessive force acts on the boom 4 and the A frame 5. This prevents the boom hoisting rope 10 from being wound up.

If the portable operation device 41 as described above is provided, the worker holds the portable operation device 41 and places the A frame 5 and the counterweight 1 on the ground or on the upper swing body 2.
By operating the operation switches 41a to 41g of the portable operation device 41 while watching the 7 and the like, the control valve 24 can be switched and operated via the pilot valve 42, and the hydraulic cylinders 15a and 15b can be operated. Since the control valves 29 and 30 can be operated,
The counterweight can be attached and detached by a human operator.

Further, if the A frame rising angle limiting means such as the limit switch 44 is provided, the winch 13 is erroneously operated excessively in the winding direction when the counterweight 17 is mounted or the like. Excessive force is prevented from acting on the boom 4 and the boom 4, and breakage of these can be prevented. As a means for detecting the upper limit of the rising angle of the A frame 5, other detectors such as a magnetic type, an electromagnetic type, and a photoelectric conversion type can be used.

FIG. 5 is a hydraulic circuit diagram showing another example of the operation circuit of the hydraulic cylinders 15a and 15b according to the present invention.
FIG. 6 shows the portable operating device 41 and each pilot valve 42,
FIG. 4 is an electric circuit diagram showing another example of a connection relationship with control valves 29 and 30.

In this embodiment, as shown in FIG. 5, the on-off valve 2 for returning the discharge oil of the pilot hydraulic pump 21 to the tank when the counterweight 17 is not attached or detached is used.
Instead of providing the control valve 8, the control valves 29 and 30 have a circuit configuration in which the discharge oil of the hydraulic pump 21 is returned to the tank in the neutral position. As shown in FIG. The control valves 29 and 30 are provided at positions where the energization of all solenoids is controlled. In this embodiment, the same operation and effect as described above can be obtained.

In the present invention, the portable operation device 41 may be of a wireless type, instead of a wired type. In the present invention, when a hydraulic cylinder for raising and lowering the A frame 5 is provided, the counterweight may be attached and detached by raising and lowering the A frame 5 using the hydraulic cylinder for raising and lowering.

[0031]

According to the first aspect of the present invention, an operating circuit switchable by an electric signal is provided as an operating circuit of a control valve for controlling the drive of the hydraulic device for raising and lowering the A frame and the hydraulic cylinder for attaching and detaching the counterweight. Since a portable operating device for applying the remote control signal for operating the control valve to the operating circuit is provided, a single operator can perform the work of attaching and detaching the counterweight while looking at the work location, thereby achieving labor saving. . In addition, since the winch and the hydraulic cylinder are operated by one person while visually observing the work place, the counterweight attaching / detaching operation can be performed safely and reliably.

According to the second aspect, since the means for limiting the rising angle of the A frame is provided, it is possible to prevent the boom and the A frame from being damaged due to excessive winding of the boom hoisting rope.

[Brief description of the drawings]

FIG. 1 is a side view of a crane showing one embodiment of the present invention.

FIGS. 2 (A) and 2 (B) are hydraulic circuit diagrams of the boom hoisting winch and the hydraulic cylinder for attaching / detaching a counter weight in the embodiment of FIG. 1, respectively.

FIG. 3 is an electric circuit diagram showing a connection relationship between the portable operation device of the embodiment of FIGS. 1 and 2 and a control valve and the like.

FIG. 4 is a side view showing an arrangement of a detector for restricting a rising angle of an A frame in the embodiment shown in FIGS. 1 to 3;

FIG. 5 is a hydraulic circuit diagram showing another embodiment of the present invention.

6 is an electric circuit diagram showing a connection relationship between the portable operation device of the embodiment of FIG. 5 and a control valve or the like.

[Explanation of symbols]

1: Lower traveling structure, 2: Upper revolving structure, 3: Revolving device, 4:
Boom, 5: A frame, 6: Backstop, 10:
Boom hoisting rope, 13: winch, 15a, 15b:
Hydraulic cylinder, 17: counter weight, 22: pilot valve, 26: hydraulic motor, 29, 30: control valve, 41: pendant switch, 42: pilot valve,
44: Limit switch

Claims (2)

[Claims] 1. A counterweight attachment / detachment device for a crane, comprising: an A frame attached to an upper revolving unit by a hydraulic device so as to be able to move up and down; and a counterweight attachment / detachment hydraulic cylinder connected to the top of the A frame. As an operation circuit of a control valve for controlling the drive of the hydraulic device for raising and lowering the frame and the hydraulic cylinder for attaching and detaching the counterweight, an operation circuit switchable by an electric signal is provided, and the operation circuit is provided with a remote for operating the control valve. A counterweight attachment / detachment device for a crane, comprising a portable operation device for applying an operation signal. 2. The A-frame rising angle limiting means according to claim 1, wherein when the rising angle of the A frame exceeds a predetermined value, the rising angle is detected and the raising operation of the A frame by the hydraulic device is stopped. A counterweight attachment / detachment device for a crane, comprising: