JPS6335559B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic hoisting winch stopping device for a crane that automatically stops a hoisting winch for hoisting working tools such as a main hook and an auxiliary hook in a crane equipped with a jib.

In a crane, the main hook is suspended from the main boom with a rope, and this main hook is used to carry out the lifting work.A jib boom is also attached to the tip of the main boom, and a supplementary hook is suspended from this. Hoisting work may be carried out using hooks. Figure 1 shows the configuration of a crane equipped with such a jib boom.

FIG. 1 is a side view of a schematic configuration of a crawler crane. In the figure, 1 is the crane body, 2 is the main boom attached to the crane body, 3 is the jib boom attached to the tip of the main boom 2, 4 is the main hoisting rope suspended from the main boom 2, and 5 is the main hoisting rope A main hook is provided at the tip of the main hoisting rope 4, 6 is an auxiliary hoisting rope suspended from the jib boom 3, and 7 is an auxiliary hook provided at the tip of the auxiliary hoisting rope. Reference numeral 8 denotes a main hoisting winch that is mounted on the crane body 1 and winds up the main hoisting rope 4, and 9 is an auxiliary hoisting winch that is also mounted on the crane 1 and hoists the auxiliary hoisting rope 6. In normal work, a load is suspended from the main hook 5 or auxiliary hook 7, and the main hoist winch 8 or auxiliary hoist winch 9 is driven to hang the load or the crane body 1 is rotated to move the load to the desired position. Transfer to location. The hydraulic circuit for performing this work will be explained with reference to the following figure.

FIG. 2 is a system diagram of the hydraulic circuit and electric circuit of a conventional crane. In the figure, A is the main winch 8
B is a hydraulic circuit and an electric circuit that control the auxiliary winch 9. Since both hydraulic circuits and electric circuits have almost the same configuration, the same numbers will be used for the same components of both, and the symbols A and B will be attached to distinguish them. Only circuit A will be explained, and circuit B will be explained. is omitted. 11 is a main hydraulic pump rotatably driven by a prime mover (not shown), 12A is a hydraulic motor driven by the main hydraulic pump 11, and 13A is interposed between the main hydraulic pump 11 and the hydraulic motor 12A to control the rotation of the hydraulic motor 12A. It is a directional control valve. The directional control valve 13A has pilot chambers 13 at both ends.
A _P1 and 13A _P2 are provided, and when pilot pressure is supplied to either of the pilot chambers 13A _P1 or 13A _P2 , the neutral position shown in the figure can be switched to the left or right position. 14A is a counterbalance valve for reliably maintaining the stoppage of the hydraulic motor 12A, 15A
16 is a check valve, and 16 is a relief valve that defines the maximum pressure of the main circuit. 17 is an auxiliary hydraulic pump rotationally driven by a prime mover (not shown); 18A is a pilot valve that operates the hydraulic motor 12A by switching and controlling the directional control valve 13A; 19 is a relief valve that defines the maximum pressure of the pilot circuit; 20A
is an electromagnetic switching valve interposed between the pilot chamber 13A _P1 of the directional switching valve 13A and the pilot valve 18A. The electromagnetic switching valve 20A has an electromagnetic solenoid, and when it is de-energized, it is in the position shown in the figure and conducts the pilot chamber 13A _P1 and the pilot valve 18A, and when it is energized, it is switched to the left position in the figure and connects the pilot chamber 13A _P1 . Connect to tank. 21A is a drum shaft connected to the hydraulic motor 12A, and 22A is a hoisting drum connected to the drum shaft 21A for winding the main winding rope 4. The main winch 8 is composed of the hydraulic motor 12A, the drum shaft 21A, and the hoisting drum 22A, and the auxiliary winch 9 is composed of the hydraulic motor 12B, the drum shaft 21A, and the hoisting drum 22A. Furthermore, the main hydraulic pump 11 and the auxiliary hydraulic pump 17 are commonly used in both circuits A and B.

24A is a main overwinding prevention device (24B is an overwinding prevention device), and is composed of a weight 25A, a spring 26A, a rope 27A, and a detection switch 28A. The detection switch 28A has terminals C ₁ and C ₂ , and the terminal C ₂
is connected to the solenoid of the electromagnetic switching valve 20A. The detection switch 28A normally connects the power supply 29 to the terminal _C1 , and connects the power supply 29 to the terminal by switching operation.
C ₂ (the switching relationship between the terminals D ₁ and D ₂ in the detection switch 28B of the supplementary winding prevention device 24B is also the same). Here, the configuration of the main overwinding prevention device 24A is shown in FIG.

FIG. 3 is a side view of the main boom and main hook with the main overwind prevention device. In the figure, the same parts as those shown in FIG. 2 are given the same reference numerals. The weight 25A is inserted through the main winding rope 4 and is vertically movable. Spring 26A and detection switch 28A are fixed to main boom 2. rope 2
7A is a weight 25A and a spring 26 via a pulley 30.
Connect A. The spring 26A is constantly stretched by the weight of the weight 25A via the rope 27A. The detection switch 28A is, for example, a micro switch, and is switched to the terminal _C1 side in the above state in which the spring 26A is extended.
As the main hook 5 is hoisted up by the main winch 8, it finally comes into contact with the weight 25A and lifts it up. Therefore, the weight of the weight 25A no longer acts, the spring 26A is compressed, the detection switch 28A is activated, and the contact is switched to the _C2 side.

The structure of the auxiliary winding switch 24B is almost the same as that of the main overwinding switch 24A, except that the weight 25B is inserted through the auxiliary winding rope 6, and the spring 26 is inserted into the auxiliary winding rope 6.
The only difference is that the detection switch 28B and the detection switch 28B are fixed to the jib boom 3.

Here, the operation of the above-mentioned conventional device will be explained. When the pilot valve 18A is operated in the direction of arrow a, the pressure oil of the auxiliary hydraulic pump 17 is supplied to the pilot chamber 13A _P1 of the directional switching valve 13A via the pilot valve 18A and the electromagnetic switching valve 20A. As a result, the directional control valve 13A is switched to the left side position in the figure, and pressure oil from the main hydraulic pump 11 is supplied to the hydraulic motor 12A to rotate it in the hoisting direction. Accordingly, the hoisting drum 22A also rotates, winds up the main hoisting rope 4, hoists the main hook 5, and lifts the load suspended therefrom. When the main hook 5 is hoisted up to a predetermined height or higher, the main hook 5 contacts the weight 25A, the weight 25A is lifted, and the detection switch 2
8A is activated and connects the power supply 29 to contact _C2 .
Therefore, the solenoid of the electromagnetic switching valve 20A is energized, the electromagnetic switching valve 20A is switched to the left position in the figure, and the pressure oil in the pilot chamber 13A _P1 is discharged into the tank. As a result, the directional control valve 13A returns to the neutral position, cuts off the supply of pressure oil to the hydraulic motor 12A, and the hydraulic motor 12A stops to stop hoisting the main hook 5. In this way, excessive winding is prevented. The stoppage of the hydraulic motor 12A is reliably maintained by a counterbalance valve. Since the operation on the circuit B side is also the same, its explanation will be omitted.

By the way, in such a crane, usually the main hook 5 or the auxiliary hook 7 is used alone,
There are few work situations where both are used at the same time. However, for example, in foundation work, etc., when a long reinforcing bar frame placed on the ground is inserted into a hole drilled in the ground, it is necessary to use the main hook 5 and the auxiliary hook 7 at the same time. work is done. This is shown in FIG.

FIG. 4 is a side view of a schematic configuration of the crawler crane showing one working mode. In the figure, the same parts as those shown in FIG. 1 are given the same reference numerals. 32 is a rope connected to the main hook 5, and 33 is a rope connected to the auxiliary hook 7. 34 is the elongated reinforcing frame. Ropes 32 and 33 are tied to the reinforcing bar frame 34 placed on the ground, and the reinforcing bar frame 34 is lifted by hoisting up the main hook 5 and the auxiliary hook 7 at the same time. The crane body 1 is rotated, and the rotation is stopped at a position where one end of the reinforcing bar frame 34 on the auxiliary hook 7 side coincides with the hole drilled in the ground, and the main hook 5 and the auxiliary hook 7 are simultaneously lowered, and the reinforcing bar frame 34 is The reinforcing bar frame 34 is placed on the edge of the hole at one end of the frame, the rope 33 is removed, and this time only the main hook 5 is raised.
stand in the hole.

During this work, the main hook 5 and the auxiliary hook 7 must be kept at the same height and the reinforcing bar frame 34 must be held horizontally. If this is not done, the reinforcing bar frame 34 will tilt and fall under its own weight. Danger arises. Therefore, the automatic stopping position of the main hook 5 by the main overwinding prevention device 24A and the automatic stopping position of the supplementary hook 7 by the overwinding prevention device 24B must be kept at the same height. If they are not at the same height, even though one hook has automatically stopped, the other hook will continue to rise, creating a risk that the reinforcing bar frame 34 will tilt and fall. However, main hook 5 and supplementary hook 7
Since each automatic stop position changes depending on the angle of the main boom 2 and jib boom 3, it is extremely difficult to align these automatic stop positions at the same height. The drawback was that it was impossible to avoid the risk of falling.

An object of the present invention is to provide an automatic crane hoisting winch stop device that eliminates the above-mentioned conventional drawbacks and can make the automatic stop positions of the main work tool and the auxiliary work tool at the same height in the case of co-hanging work. There is something to do.

To achieve this objective, the present invention provides a first detection switch that is actuated when a main working implement suspended by the main boom of a crane reaches a certain predetermined height; A second detection switch that operates when the auxiliary work tool reaches a predetermined height is provided, and when the first detection switch, the second detection switch, or both are activated, the hydraulic pressure is It is characterized in that both the main winch and the auxiliary winch are stopped by returning the switching valve of the circuit to the neutral position.

The present invention will be explained below based on the embodiments shown in FIGS. 5 and 6.

FIG. 5 is a system diagram of the hydraulic circuit and electric circuit of the hoisting winch automatic stop device according to the first embodiment of the present invention. In the figure, the same parts as those shown in FIG. 2 are given the same reference numerals. This embodiment differs from the device shown in FIG. 2 only in the connection relationship of each detection switch in each overwinding prevention device, and the other configurations are the same. That is, 35A is the main overwind prevention device,
35B is an overwinding prevention device, 36A is a detection switch for the main overwinding prevention device 35A, and 36B is a detection switch for the overwinding prevention device 35B. Each of the detection switches 36A and 36B is composed of, for example, a micro switch. The detection switch 36A has terminal E ₁ ,
E ₂ , and the detection switch 36B has terminals F ₁ and F ₂ . The terminals E ₂ and F ₂ are connected to each other and also to the electromagnetic switching valves 20A and 20B.

Here, the operation of this embodiment will be explained. Now, suppose that the weight 25A is at a lower position than the weight 25B. When a long load is suspended from the main hook 5 and the auxiliary hook 7 and the hydraulic motors 12A and 12B are driven to perform the co-hanging work shown in FIG. 4, both the hooks 5 and 7 are maintained at the same height. When the load is raised while keeping it horizontal, the main hook 5 first comes into contact with the weight 25A and lifts it. Then, the detection switch 36A is activated and the contact
Switched from E ₁ to contact E ₂ , power supply 29 and contact E ₂
and are connected. For this reason, the electromagnetic switching valves 20A, 2
The 0B solenoid is energized, and each electromagnetic switching valve 20
A and 20B are simultaneously switched to the left position in the figure,
The directional control valves 13A, 13B return to their neutral positions, and the hydraulic motors 12A, 12B, and therefore the main winch 8 and the auxiliary winch 9, stop at the same time. As a result, the main hook 5 and the auxiliary hook 7 are stopped at the automatic stop position of the main hook 5, and the same height is maintained, so that the load does not tilt. Also, on the contrary, weight 25B
Even when the hook is at a lower position than the weight 25A, the detection switch 36B is operated to perform exactly the same operation as in the above case, and the main hook 5 and the auxiliary hook 7 are held at the same height.

As described above, in this embodiment, the detection switch of the main overwinding prevention device and the detection switch of the supplementary winding prevention device are connected in parallel, and when either or both detection switches are activated, the main winding winch is controlled. The electromagnetic switching valve of the hydraulic circuit that controls the auxiliary hoisting winch and the electromagnetic switching valve of the hydraulic circuit that controls the auxiliary hoisting winch are simultaneously driven to automatically stop the main hoisting winch and the auxiliary hoisting winch at the same time. The main hook and the auxiliary hook can be held at the same height, preventing the load from falling.

FIG. 6 is an electrical circuit diagram of a hoisting winch automatic stop device according to a second embodiment of the present invention. In the figure, the same parts shown in FIG. 2 are given the same reference numerals.
Since the hydraulic circuit used in this embodiment is the same as the hydraulic circuit shown in FIGS. 2 and 5, illustration thereof is omitted in FIG. 6 except for the electromagnetic switching valves 20A and 20B. 37A is the main overwind prevention device,
37B is an overwinding prevention device, 38A is a detection switch for the main overwinding prevention device 37A, and 38B is a detection switch for the overwinding prevention device 37B. Detection switch 3
8A has contacts G ₁ , G ₂ , G ₃ and detects switch 3
8B has contacts H ₁ , H ₂ , and H ₃ . Contact G ₃ is a contact
H ₁ and contact H ₃ is grounded. 39
is a relay connected between power supply 29 and contact _G1 ,
39a is a contact point of the relay 39. The detection switch 38A connects the contact _G1 and the contact _G3 when the weight of the weight 25A is applied, and when the weight 25A is lifted by the main hook 5, the switch 38A switches and closes the contact.
Connect G ₁ and contact G ₂ . Detection switch 38B contacts H ₁ when the weight of weight 25B is acting.
When the weight 25B is lifted by the auxiliary hook ₇ , it is switched to connect the contacts _H1 and _H2 . Also, the contact 39 of the relay 39
a is opened when the relay 39 is energized, and closed when the relay 39 is de-energized.

Next, the operation of this embodiment will be explained. Now, suppose that the co-hanging work is carried out with the weight 25A at a lower position than the weight 25B. When the main hook 5 and the auxiliary hook 7 are in a low position and the weight of the weights 25A and 25B is acting, the detection switches 38A and 38B are in the state shown, and the relay 39 is energized and its contact 39a is opened. There is. When the main hook 5 and the auxiliary hook 7 rise while maintaining the same height, first, the weight 2
5A comes into contact with the main hook 5 and is lifted, the detection switch 38A is actuated and switched, and the connection between the contact _G1 and the contact _G3 is cut off. As a result, the relay 39 is de-energized, the contact 39a is closed, the electromagnetic switching valves 20A and 20B are simultaneously driven, the hydraulic motors 12A and 12B are stopped, and the main winch 8 and the auxiliary winch 9 are therefore stopped at the same time. do. At this time, the main hook 5 and the auxiliary hook 7 are held at the same height, and the load does not tilt. Conversely, when the weight 25B is at a lower position than the weight 25A, the circuit of the relay 39 is cut off by switching the detection switch 38B, and thereafter the main hook 5 and the auxiliary hook 7 are operated in exactly the same manner as described above.
are held at the same height.

As described above, in this embodiment, the detection switch of the main overwinding prevention device and the detection switch of the supplementary winding prevention device are inserted in series in the relay circuit, and when either or both detection switches are activated, the relay circuit is activated. is de-energized and its contacts are closed, and the solenoid switching valve in the hydraulic circuit that controls the main winch and the solenoid switching valve in the hydraulic circuit that controls the auxiliary winch are simultaneously driven to automatically operate the main winch and the auxiliary winch at the same time. Since it is designed to stop, not only does it have the same effect as the previous embodiment, but also when a circuit using a relay is used for the overwinding prevention device in the conventional example shown in FIG. However, in this embodiment, the relay can be shared and one relay can be omitted.

As described above, the present invention includes a first detection switch that operates when the main working tool suspended by the main boom of the crane reaches a predetermined height, and an auxiliary working tool suspended by the jib boom of the crane. and a second detection switch that operates when the hydraulic circuit reaches a predetermined height, and when the first detection switch and/or the second detection switch is activated, the switching valve of the hydraulic circuit is returned to the neutral position and the main Since both the hoisting winch and the auxiliary hoisting winch are stopped, the main work tool and the auxiliary work tool can be held at the same height during crane co-hanging work, preventing the risk of the load falling. Can be done.

[Brief explanation of the drawing]

Figure 1 is a side view of the general configuration of a crawler crane, Figure 2 is a system diagram of the hydraulic circuit and electric circuit of a conventional crane, and Figure 3 is a side view of the main boom and main hook equipped with a main overwind prevention device. , FIG. 4 is a side view of a schematic configuration showing one working mode of the crawler crane, FIG. FIG. 6 is an electric circuit diagram of a hoisting winch automatic stop device according to a second embodiment of the present invention. 2... Main boom, 3... Jib boom, 4... Main hoisting rope, 5... Main hook, 6... Auxiliary hoisting rope, 7... Auxiliary hook, 8... Main hoisting winch, 9...
...Auxiliary winch, 11...Main hydraulic pump, 12
A, 12B...Hydraulic motor, 13A, 13B...
Directional switching valve, 20A, 20B...Solenoid switching valve, 2
2A, 22B...Hoisting drum, 25A, 25B...
...Weight, 26A, 26B...Spring, 27A, 2
7B...Rope, 35A, 37A...Main overwinding prevention device, 35B, 37B...Supplementary winding prevention device, 36
A, 36B, 38A, 38B...detection switch,
39...Relay, 39a...Contact.

Claims (1)

[Claims] 1 A main winch that hoists the main work tool, an auxiliary winch that hoists the auxiliary work tool, a first switching valve that controls the drive of the main winch, and a second winch that controls the drive of the auxiliary winch. a first detection switch that operates when the main work tool reaches a certain predetermined position; and a first detection switch that operates when the auxiliary work tool reaches a certain predetermined position. and a second detection switch that drives the first switching valve and the second switching valve when at least one of the first detection switch and the second detection switch is activated to operate the main winch and the second detection switch. A hoisting winch automatic stopping device for a crane, characterized in that the crane hoisting winch automatic stopping device is provided with a stopping means for stopping the auxiliary hoisting winch.