JPH04223992A - Rope swinging angle detecting device of crane - Google Patents

Abstract

PURPOSE:To make correct detection of a swinging angle of a hoisting rope in the longitudinal direction relative to the vertical line. CONSTITUTION:In a crane where a sheave 5 is mounted rotatably on a boom top part 3a through a sheave pin 6 and a hoisting rope 2 hangs down through the sheave 5, there are mounted rotatably on the boom top part 3a an oscillating lever 7 and a vertical indicating level 12 respectively about the shaft center axis X same as that of the sheave pin 6, and constitution is so made that the oscillating lever 7 may oscillate in the longitudinal direction following the inclination of the hoisting rope 2 in the longitudinal direction relative to the vertical line V by providing rope guide parts 11, 11 to guide the hung-down hoisting rope 2. On the other hand, there are mounted a rotational angle meter 14 to the vertical indicating lever 12 in an integrated and rotatable manner, and an input shaft 16 of the rotational angle meter 14 is connected to the oscillating lever 7 in an integrated and rotatable manner.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the swing angle (inclination angle) of a hoisting rope in the longitudinal direction with respect to a vertical line in a crane.

0002

2. Description of the Related Art During crane work, if the suspended load W is not vertically below the top 1a of the boom 1 at the moment when the suspended load W is hoisted from the ground as shown in FIG. Shaking occurs.

[0003] In order to prevent such load swinging, crane control is used to move the boom top 1a (the center line of the hoisting rope 2) onto a vertical line passing through the center of the suspended load by extending/contracting or adjusting the elevation of the boom 1. As a precondition for this, it is necessary to detect the deflection angle θ of the hoisting rope 2 with respect to the vertical line V.

[0004] Conventionally, as a means for detecting this rope deflection angle, Japanese Patent Application Laid-open No. 1-13389 and Japanese Utility Model Application No. 63-
The one shown in Japanese Patent No. 4989 is publicly known.

In the former (hereinafter referred to as prior art 1),
A swinging lever is hung from the top of the boom so that it can swing back and forth following the hoisting rope, and a potentiometer is provided at the base of the swinging lever. The swing angle of the rope is detected.

On the other hand, the latter (hereinafter referred to as prior art 2)
In this case, an angle sensor is installed at the base of the boom to detect the angle of the boom relative to the ground, and a potentiometer is installed at the top of the boom to detect the angle of the hoisting rope with respect to the boom reference line perpendicular to the boom axis. From these detected values, the swing angle of the rope can be determined. I'm trying to find out.

[0007]

However, since both of the prior art techniques 1 and 2 detect the angle formed between the boom and the hoisting rope, they have the following drawbacks.

That is, in these conventional techniques, as a prerequisite for detecting the rope swing angle, it is necessary to accurately detect the boom angle at that time.

However, (1) In the telescopic boom, since there is play in the fitting portions of the booms, the linearity of the boom cannot be ensured, especially when the boom is extended for a long time.

(2) When the hanging load is large, the boom is elastically deformed.

[0011] For this reason, the accuracy of detecting the boom angle as a prerequisite deteriorates, so that the target swing angle of the rope cannot be detected accurately.

Furthermore, in prior art 2, the angle of the boom relative to the ground is detected with the supporting surface of the crane being horizontal.
If this support surface is inclined, the detection of the boom to the ground angle itself becomes inaccurate, and the detection accuracy of the rope swing angle becomes even worse.

Furthermore, in prior art 1, each time the boom angle changes, the rope is vertically suspended at the boom angle state at that time to set it as the origin (potentiometer output 0), and the rope is suspended from this origin at the time of ground cutting. So-called origin correction is required to detect the deflection angle.

However, in this case, once the rope swing angle is detected, and the boom is adjusted based on this detection result so that the top of the boom is vertically above the hanging load center, the origin also changes, and the rope It becomes impossible to detect the deflection angle. Therefore, it is not possible to grasp the change in the swing angle of the rope as a result of the adjustment of the boom, making it difficult to achieve the intended purpose of preventing the load from swinging.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a rope swing angle detection device for a crane that can always accurately detect the rope swing angle as an angle with a vertical line rather than an angle with a boom. .

[0016]

[Means for Solving the Problems] The present invention provides a crane in which a sheave is rotatably attached to the top of the boom via a sheave pin, and a hoisting rope is passed through the sheave and hangs down. and a vertical indicator lever are respectively mounted rotatably around the same axis as the sheave pin, and the swinging lever is provided with a rope guide section that guides the hanging hoisting rope. It is constructed so that it can swing back and forth following the longitudinal inclination of the hoisting rope with respect to the line, and on the other hand, a rotation angle meter is attached to the vertical indicator lever so that it can rotate together with the lever. The input shaft is connected to the swinging lever so that it can rotate integrally with the swinging lever.

[0017]

[Operation] According to the above structure, the swing lever swings following the hoisting rope, and the movement of the swing lever is transmitted to the input shaft of the rotation angle meter. On the other hand, the vertical indicator lever is always in a vertical state, and the movement of the vertical indicator lever is transmitted to the housing (fixed part) of the rotation angle meter.

[0018] When the rope swing angle is 0, both levers are vertical, so the angle formed by these levers is 0.
becomes. Therefore, if the output of the rotation angle meter at this time is set to 0, the angle formed by both levers will be detected as the swing angle of the rope when the hoisting rope is tilted with respect to the vertical line.

That is, according to this configuration, since the angle formed by the vertical indicator lever and the swinging lever is detected as the swing angle of the rope with respect to the vertical line, there is no need to detect the boom angle as a premise as in the past, and rotation It becomes possible to directly detect the rope swing angle using only the angle meter.

[0020] Therefore, the swing angle of the rope can always be accurately detected regardless of the deflection of the boom due to play between booms in the telescopic boom, the inclination of the support surface of the crane, etc.

[0021] In addition, the conventional origin correction is no longer necessary, and changes in the rope swing angle relative to the vertical line can be detected as they are, so changes in the rope swing angle, which are the result of boom heave adjustment before ground cutting, can be monitored in real time. can be detected and understood.

[0022]

[Embodiment] An embodiment of the present invention will be explained with reference to FIGS. 1 to 4.

In this embodiment, a jib 3 as an auxiliary boom is extended from the tip of the main boom 1 shown in FIG. This example assumes a case in which the hanging work is carried out using a so-called single rope, in which the rope is suspended through a rope 5 and a hook (not shown) is attached to the end thereof. However, the present invention is similarly applicable to the case where the hoisting rope 2 is suspended from the tip of the main boom 1 as shown in FIG. 5 to perform the lifting work.

Both ends of the main sheave pin 6 that supports the main sheave 5 extend outside the sheave block 3a, as shown in FIG. The upper end portion is rotatably attached around the sheave pin axis X via a ring-shaped lever attachment member 8, and thereby the lever 7 is supported so as to be swingable in the front and rear directions about the sheave pin axis X.

A pair of left and right brackets 9 and 10 are provided at the lower end of the swing lever 7.
, 10, a pair of front and rear rope guide rollers (hereinafter simply referred to as rollers) 11, 11 are provided with an interval approximately equal to the diameter of the rope 2, and these rollers 11, 11
A hoisting rope 2 is passed between them.

As a result, the swinging lever 7 is tilted in the front-back direction following the inclination of the hoisting rope 2, and the rope 2 is tilted in the pre-ground state shown in FIG. The deflection angle θ directly becomes the inclination angle of the lever 7 with respect to the vertical line V. That is, by detecting the inclination angle of the swing lever 7, the swing angle θ of the rope 2 can be detected.

Note that the swinging lever 7 is connected to the lever mounting member 8, and both rollers 11, 11 are connected to the brackets 9, 10.
They are each removably attached to the vehicle, and can be removed if they become an obstacle (for example, when the crane is traveling). In addition, the hoisting rope 2 is connected to both rollers 11
, 11, it is desirable that both rollers 11, 11 be made of rubber or have rubber attached to their circumferential surfaces.

A vertical indicator lever 12 is attached to the other end of the main sheave pin 6 so as to be able to swing around the main sheave pin axis X so that the vertical position is always maintained regardless of changes in the boom angle. An encoder 14 as a rotation angle meter is installed on the outer surface of the vertical indicator lever 12 via a cover member 13.
A housing 15 is attached so as to be rotatable together with the vertical indicator lever 12.

The input shaft 16 of the encoder 14 is connected via a coupling 18 to one end of a transmission shaft 17 which is rotatably provided at the axial center of the main sheave pin 6 about the pin's axis X. The other end of the transmission shaft 17 is connected to the lever mounting member 8 via the cover member 19.

In this way, the rocking motion of the rocking lever 7 is transmitted to the input shaft 16 of the encoder 14 via the lever mounting member 8, the cover member 19, and the transmission shaft 17, and the rocking motion of the vertical indicator lever 12 is transmitted to the input shaft 16 of the encoder 14 via the lever mounting member 8, the cover member 19, and the transmission shaft 17. The signal is configured to be transmitted to the housing 15 of the encoder 14 via the member 13.

Further, two rotary dampers 20, 20 are provided on the outer surface of the sheave block 1a, and these rotary dampers 20, 20 and the housing 1 of the encoder 14
5 are interlocked and connected via gears 21 and 22.

As is well known, the rotary damper 20 includes a cylindrical rotor 20a and a viscous material (not shown) such as grease that provides a predetermined rotational resistance to the rotor. The damper 20 suppresses vibrations of the vertical instruction lever 12 when the boom is extended and retracted, and when the boom is raised and lowered.

The encoder 14 is connected to the input shaft 1 as is well known.
6 and a fixed plate (not shown) attached to the housing 15, and this detection signal is sent to a controller (not shown).

When starting the crane work, both the swing lever 7 and the vertical indicator lever 12 are set to the vertical position, and the output of the encoder 14 at this time is set to 0 (the relative rotation amount of both levers 7 and 12 is 0). ).

Therefore, during the subsequent work, both levers 7 and 1
As long as both the hoisting ropes 2 and 2 are kept vertical, that is, as long as the hoisting rope 2 does not tilt in the longitudinal direction, there will be no relative rotation between the rotary plate 16a and the fixed plate, so the encoder output will be 0 (rope deflection). The angle is 0).

[0036] When cutting the ground during work, the hoisting rope 2
When the lever 7 is tilted, the swinging lever 7 tilts from the vertical direction in the front and back direction as shown in FIG.
12, that is, a relative rotation occurs between the rotary plate 16a and the fixed plate of the encoder 14, and this is detected as the deflection angle θ of the rope 2.

[0037] This detection signal is sent to the controller,
Based on the control signal from the controller according to this detected value (the direction of deflection is distinguished by, for example, + or -), the boom 1 is extended/contracted, raised and lowered, or both of the boom operations are performed so that the rope deflection angle θ becomes 0. After this control is completed, the hoisting rope 2 is hoisted up and ground cutting is performed.

[0038] Instead of automatically controlling the boom 1 based on the detection signal of the encoder 14 as described above, the detection signal is taken into the display section of the controller and the rope swing angle θ is displayed to the operator. It is also possible to manually control the boom 1 based on this display so that the swing angle θ becomes 0.

Further, the rotation angle meter is not limited to the encoder 14 used in the above embodiment, but a potentiometer, for example, may be used.

[0040]

[Effects of the Invention] As described above, according to the present invention, since the angle formed by the swinging lever with respect to the vertical indicator lever is detected as the rope swing angle by a rotation angle meter, the angle of the rope with respect to the boom is detected as in the conventional method. There is no risk of detection errors occurring due to bending of the boom due to play between the booms in the telescopic boom, deflection of the boom due to the amount of suspended load, or even inclination of the support surface of the crane. Therefore, the rope deflection angle can always be accurately detected.

[0041] Furthermore, when the boom angle changes due to boom elevation adjustment during ground cutting, the accompanying change in the rope swing angle is directly detected by the rotation angle meter.
It is no longer necessary to correct the origin every time the boom angle changes as in the past, and it is possible to detect and understand changes in the rope swing angle as a result of boom heave adjustment in real time. Therefore, especially when manually controlling the boom based on the detection signal, accurate control can be performed while checking the state of change in the rope swing angle.

[Brief explanation of the drawing]

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

FIG. 2 is an enlarged sectional view taken along the line E--I in FIG. 1;

FIG. 3 is a sectional view taken along the Ro-Ro line in FIG. 2;

FIG. 4 is a side view taken along the line Ha-Ha in FIG. 2;

FIG. 5 is a schematic side view of a crane for explaining the technical background of the present invention.

[Explanation of symbols]

2 Hoisting rope 3 Jib (auxiliary boom) 3a Sheave block 5 at the tip of the jib as the top of the boom Sheave provided on the sheave block 6 Sheave pin X Sheave pin axis 7 Swing levers 11, 11 Guides forming the rope guide section Roller 12 Vertical indicator lever 14 Encoder 15 as a rotation angle meter Encoder housing (fixed part) 16 Input shaft 17 Transmission shaft

Claims (1)

[Claims] Claim 1: A crane in which a sheave is rotatably attached to the top of the boom via a sheave pin, and a hoisting rope is passed through the sheave and suspended, and a swing lever and a vertical indicator lever are respectively provided at the top of the boom. The swing lever is mounted rotatably around the same axis as the sheave pin, and the swing lever is provided with a rope guide section that guides the hanging hoisting rope. On the other hand, a rotation angle meter is attached to the vertical indicator lever so that it can rotate integrally with the lever, and the input shaft of this rotation angle meter is attached to the vertical indicator lever. A swing angle detection device for a rope in a crane, characterized in that the device is rotatably connected to the same lever.