JP2552639Y2 - Overhang prevention device for lifting equipment of mobile crane - Google Patents

Description

[Detailed description of the invention]

[0001]

[Industrial application field] The present invention relates to the suspension of a mobile crane.
The present invention relates to a device for preventing winding of a tool .

[0002]

2. Description of the Related Art As shown in FIG.
A swivel (not shown) rotatably mounted on the vehicle is provided with a boom 1 mounted to be able to move up and down, and a hydraulic drive winch 3 pulled out through a sheave 2 at the tip of the boom 1 is provided. Boom 1 via wire rope 4
The hanging tool 5 is hung from the tip part of the. The drive speed and drive direction of the hydraulic drive winch 3 are controlled by a drive control device 6 including a four-way three-position hydraulic control valve 6a.

[0003] This type of mobile crane is provided with an overwinding prevention device for preventing the lifting tool 5 from being hoisted up and driven to collide with the end of the boom 1. The conventional winding prevention device includes a stop switch 7 disposed at the end of the boom 1 for detecting when the hanger 5 comes to a stop position approaching the end of the boom 1, and operates based on the detection result of the stop switch 7. The winding stop means 8 is provided. Although the stop switch 7 is attached to the end of the boom 1, the arrangement of the stop switch 7 at the end of the boom 1 is omitted in FIG. 2, and the hanging member 5 is wound up in the electric circuit. Stop switch that shuts off when the
Shown as h7 . The mounting configuration of the stop switch 7 to the tip of the boom 1 is well known. In FIG. 2, the hoisting stop means 8 is interposed between the pump oil passage 6b of the hydraulic switching valve 6a in the drive control device 6 and the tank, and unloads the amount of hydraulic oil flowing through the pump oil passage 6b during its operation. Shown as unload valve. The distance between the suspender 5 and the end of the boom 1 at the stop position is determined by the detection result of the stop switch 7 under the condition that the hydraulic drive winch 3 is driven to hoist at the highest speed (the hoist 5 is driven to hoist at the highest speed). The lifting of the hydraulic drive winch 3 by the lifting stop means 8 is stopped by the lifting tool 5 at the end of the boom 1.
The distance is set to have a sufficient time margin before the collision occurs.

In the conventional winding prevention device configured as described above, the distance between the suspender 5 and the end of the boom 1 at the stop position is determined by the hydraulic drive winch 3 being wound up at the highest speed (the hoist 5 is moved at the highest speed). Since it is set assuming the state of hoisting drive), it becomes large and there is a problem that the working range of the mobile crane is limited accordingly.

[0005]

[Problems to be Solved by the Invention] The present invention secures a time margin required for stopping the hoisting motion of the hanging tool 5 before the hanging tool 5 collides with the tip of the boom 1,
An object of the present invention is to provide an overwinding prevention device capable of expanding the working range of a mobile crane by setting a small distance between the hanging tool 5 and the end of the boom 1 at the stop position.

[0006]

Means for Solving the Problems In order to achieve the above object, a device for preventing winding of a hanging tool of a mobile crane according to the present invention is configured as follows. An anti-winding device used in a mobile crane in which a hanging tool 5 is suspended from the distal end of the boom 1 via a wire rope 4 from a hydraulic drive winch 3 pulled out through a sheave 2 at the distal end of the boom 1. A stop switch 7 disposed at the end of the boom 1 for detecting when the hanger 5 comes to a stop position approaching the end of the boom 1, and a hoisting stop means operated based on the detection result of the stop switch 7. 8, the drive control device 6 for the hydraulic drive winch 3 is provided with a drive speed regulating means for regulating the drive speed of the winch 3 to a predetermined value or less at the time of its operation, and is disposed at the end of the boom 1. A speed regulating switch for detecting a position where the distance between the hanging member 5 and the end of the boom 1 is farther than the stop position is attached, and the driving speed is determined based on the detection result of the speed regulating switch. Hanging mobile crane, characterized by being configured to actuate the braking means
Device for preventing the tool from winding.

[0007]

The mobile crane of the present invention configured as described above.
The drive speed of the hydraulic drive winch 3 is restricted to the maximum speed or less at a position where the distance between the hanger 5 and the tip of the boom 1 is farther than the stop position. Even if the distance between the lifting tool 5 and the end of the boom 1 is set smaller than that of the conventional one, and the working range of the mobile crane is expanded, the lifting movement of the lifting tool 5 causes the lifting tool 5 to rotate the boom 1.
The time margin necessary for stopping the vehicle before colliding with the tip can be secured.

[0008]

An embodiment of the present invention will be described below with reference to FIG. The device for preventing the winding of the hanging tool of the mobile crane according to the present invention is obtained by adding a part of the structure to the device for preventing the winding of the conventional mobile crane . Transfer
The reference numerals used in the description of the apparatus for preventing winding of a hanging tool of a dynamic crane and the description thereof are incorporated in the following description as they are.

In FIG. 1, reference numeral 9 denotes a throttle valve interposed in the pump oil passage 6 b of the hydraulic switching valve 6 a in the drive control device 6 to limit the amount of hydraulic oil flowing through the pump oil passage 6 b during operation. This throttle valve 9 corresponds to the drive speed regulating means in the claims for utility model registration.
When the throttle valve 9 operates, the drive speed of the hydraulic drive winch 3 is regulated to a predetermined value or less. In other words, the maximum drive speed of the hydraulic drive winch 3 is reduced. Reference numeral 10 denotes a speed regulating switch which is disposed at the tip of the boom 1 and detects a position where the distance between the hanging member 5 and the tip of the boom 1 is farther than the stop position (the detection position of the stop switch 7). The speed regulating switch 10 has a weight 10c connected to its operating arm 10a via a rope 10b.
Is suspended, and when the weight 10c is lifted by the hanging tool 5, it is configured to close. Speed limit switch 10, so that the detection result by the driving speed regulating means (throttle valve) 9 is operated, and is electrically connected to the driving speed regulating means 9.

In this embodiment, an example is shown in which the drive speed regulating means 9 is constituted by a solenoid-operated throttle valve. However, the drive speed regulating means 9 may be replaced with, for example, the following. It is. The adjustment range of the engine rotation speed by the accelerator mechanism of the engine (not shown) that drives the hydraulic pump 6c (a hydraulic pump that supplies hydraulic oil to the hydraulic switching valve 6a via the pump oil passage 6b) is reduced to a predetermined rotation speed or less. What to regulate. Hydraulic control valve 6a is composed of an electromagnetic proportional control valve .
Further, by regulating the upper limit of an operating electric signal for operating the electromagnetic proportional control valve, the operation amount of the electromagnetic proportional control valve is regulated to a predetermined value or less.

The mobile crane of the present invention configured as described above
When the hoisting device 5 is driven up, the distance between the hoisting device 5 and the end of the boom 1 is at the stop position.
The speed regulation switch 10 detects this at a position farther away than this, and the drive speed regulation means 9 is operated based on the detection result, and the drive speed of the hydraulic drive winch 3 is regulated below the maximum speed. In the stop position, the hoisting speed of the hanging tool 5 does not reach the normal maximum speed. Therefore, even if the distance between the hanger 5 and the end of the boom 1 at the stop position is set to be smaller than that of the conventional one, and the working range of the mobile crane is expanded, the lifting movement of the hanger 5 is not affected. The time margin required to stop the vehicle before it hits the end of the boom 1 can be secured.

[0012]

[Effects of the Invention] The mobile device of the present invention configured as described above
The overhang prevention device for the hanging device of the lane has a simple configuration, and even if the distance between the hanging device 5 and the end of the boom 1 at the stop position is set smaller than that of the conventional overwrap prevention device, It is possible to secure a time margin necessary for stopping the hoisting movement of the hook 5 before the hanging tool 5 collides with the tip of the boom 1. Therefore, the effect that the working range of the mobile crane can be expanded by setting the distance between the hanging tool 5 and the end of the boom 1 at the stop position to be small can be achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a device for preventing winding of a mobile crane according to the present invention.

FIG. 2 is an explanatory view of a conventional device for preventing winding of a mobile crane.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Boom 2 Sheave 3 Hydraulic drive winch 4 Wire rope 5 Hanging device 6 Drive control device 7 Stop switch 8 Winding stop means 9 Drive speed regulation means (throttle valve) 10 Speed regulation switch

Claims (1)

(57) [Scope of request for utility model registration] An anti-overwinding device used in a mobile crane in which a hanging tool is suspended from the end of a boom via a wire rope from a hydraulic drive winch pulled out through a sheave at the end of the boom. A stop switch that is disposed at the boom tip and that detects when the hanger comes to a stop position approaching the boom tip, and a hoisting stop means that operates based on the detection result of the stop switch, A drive control device for controlling the drive speed of the winch to a predetermined value or less when the hydraulic drive winch is operated is attached to the drive control device of the hydraulic drive winch, and the distance between the hanging tool and the boom tip located at the boom tip is reduced. A speed regulating switch for detecting a position farther than the stop position is attached, and the drive speed regulating means is operated based on a detection result of the speed regulating switch. Mobile crane, characterized in that configuration the
A device for preventing winding of hanging equipment.