JP2001039669A - Load detection device for crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a crane lifting load according to an angle of a boom pendant rope relative to ground. SOLUTION: This crane is formed so that a pendant rope 7 is connected to a boom pendant rope foot fixing part 17 of a boom 5 through a boom pendant rope tension detector 15. A boom pendant rope angle detector 18 is installed on the boom pendant rope 7, and a boom angle detector 16 is installed on the boom 5 to detect a tension T of the boom pendant rope 7, angle α of the boom 5 relative to the ground, and angle β of the boom pendant rope 7 relative to the ground. When the values T, α, and β are outputted from these detectors, a calculator 19 calculates a moment arm length H of the boom pendant rope 7 according to a sag of the boom pendant rope 7 based on a distance L between a boom foot 21 and the pendant rope foot fixing part 17 and an angle γ between a connection line X formed by connecting the boom foot 21 and the pendant rope foot fixing part 17 and a boom centerline O. Then, a crane lifting load can be calculated by calculating a moment ratio of the crane about the boom foot 21 with the moment arm length H used as a calculation element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load detecting device for a crane, and more particularly to a load detecting device for a crane configured to calculate a boom hanging load corresponding to a ground angle of a pendant rope. is there.

[0002]

FIG. 5 shows a conventional self-propelled large crane 1 of this kind. The crane 1 has a main body 4 composed of a lower traveling body 2 and an upper revolving superstructure 3, and a boom 5 and a mast boom 6 are pivotally supported at the front and rear portions of the main body 4 so as to be able to rotate back and forth. . A boom pendant rope 7 and a hook rope 8 are suspended from the boom 5, and the hook rope 8 is wound around a winch unit 9 for loading and unloading the main body 4, and a mast hoisting rope 10 is connected to the boom pendant rope 7. Then, the mast hoisting rope 10 is wound around the mast hoisting winch unit 11 of the main body 4. Then, one end is connected to the rear part of the upper revolving unit 3, and the connecting arm 12 is attached so as to be vertically rotatable. A weight truck 13 is connected to the other end of the connecting arm 12, and the weight truck 13 and the mast boom 6 are connected. Is connected with the suspension pendant rope 14 to ensure the stability of the crane 1 against overturning.

[0003]

In the crane 1 described above, the suspended load of the crane 1 is determined by the value detected by the tension detector 15 connecting the boom 5 and the boom pendant rope 7, the boom angle (ground angle), and the crane 1 Working radius (memory value)
Can be obtained by calculating the moment ratio between the overturning moment and the stable moment of a calculating means (not shown) using the above as a calculation element. However, as the weight bogie 13 is required, the crane boom length and the mast boom length are increased. Boom 5
If the span between the boom pedestal rope 7 and the mast boom 6 is set large, the droop of the pendant rope 7 due to its own weight increases, and the moment arm length of the boom pendant rope 7 around the boom foot 17 changes. Occurs.

Therefore, the present invention has a technical problem to be solved in order to calculate the hanging load of the crane corresponding to the weight of the pendant rope, and the present invention has an object to solve the problem. I do.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above object, and has a pendant rope angle detector for detecting a ground angle of a pendant rope, and a pendant rope for detecting tension of the pendant rope. A tension detector, a boom angle detector for detecting a boom ground angle, an output value of these detectors, a distance from the boom foot to a pendant rope base, and a connecting line connecting the boom foot and the pendant rope base. After calculating the moment arm length of the pendant rope corresponding to the hanging of the pendant rope based on the included angle with the boom center line,
An object of the present invention is to provide a load detecting device for a crane, comprising: a calculator for calculating a hanging load of the crane by calculating a moment ratio of the crane around the boom foot using the moment arm length as a calculating element.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention applied to a large self-propelled crane will be described below in detail with reference to FIGS. The same components as those of the crane described in the related art are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 shows a large self-propelled crane 1. The crane 1 is provided with a boom angle detector 16 for detecting a ground angle α of the boom 5 on the boom 5.
And the boom pendant rope 7 are connected by a boom pendant rope tension detector (a load cell or the like) 15, and the tension T of the boom pendant rope 7 is detected by the boom pendant rope tension detector 15. Then, a boom pendant rope angle detector 18 is interposed in the boom pendant rope 7, and the boom pendant rope angle detector 18 detects the ground angle β of the boom pendant rope 7.

As shown in FIG. 2, the boom angle detector 16, the boom pendant rope tension detector 15
And the detection values of the boom pendant rope angle detector 18 are output in parallel to the calculator 19, respectively.

The arithmetic unit 19 comprises a CPU, a memory, an I / O
And the like, the tension T of the boom pendant rope 7, the ground angle α of the boom 5, the ground angle β of the boom pendant rope 7, and various stored values (described later) stored in the internal memory in advance. The lifting load W of the crane 1 is calculated based on the calculated value, and the calculated lifting load W is output to the overload prevention device 20.

FIG. 3 shows an operation procedure of the operation unit 19.
The arithmetic unit 19 calls the tension T of the boom pendant rope 7, the ground angle α of the boom 5 and the ground angle β of the boom pendant rope 7 in step 1, and then proceeds to step 2 to store the boom foot 21 and the boom The distance L to the pendant rope base 17 and the boom foot 2
Connecting line X connecting 1 to boom pendant rope base 17
And the included angle γ between the boom center line O (FIGS. 1 and 4)
(A)).

Then, the routine proceeds to step 3, where the following equation (1) is obtained.
Then, the moment length H of the boom pendant rope 7 corresponding to the hanging down of the boom pendant rope 7 is calculated (see FIGS. 1 and 4B).

H = L × tan (α + γ−β) (1) where L and γ are different values for each boom. Further, the process proceeds to step 4 to obtain the following equation (2) and equation (3). The suspension load W acting on the boom 5 is calculated (see FIGS. 1 and 4A and 4B), and the result is output to the overload prevention device 20.

[0013] _{W = (N B × T ×} H-M O) / (R H -h / N W) ...... (2) R H = R-S ...... (3) However, N _B: boom pendant rope 7 multiplied number M _O: self-weight moment (memory value) of the boom 5 R: working radius (value calculated by the boom length and boom angle) R _H: horizontal distance from the suspended load 22 to Bumufuto 21 h: hook rope 8 Moment (memory value) of the boom foot 21 N _W : Number of hook ropes 8 S: Horizontal distance from the turning center of the body to the boom foot 21 Therefore, the boom length and the mast boom length are increased as the weight bogie 13 is required. Boom 5 and mast boom 6
Even with the large crane 1 having a large span between them, an accurate suspension load W corresponding to the weight drop (dip) of the pendant rope 7 can be obtained.

On the other hand, the overload prevention device 20 is composed of a microcomputer similarly to the arithmetic unit 19, and stores the total rated load data, that is, the upper limit data of the lifting load W1 in an internal memory.

The working radius of the crane 1 is calculated based on the angle detection signal of the boom angle detector 16 and the attachment configuration information input by the operator, and the working radius is calculated by the calculator 19. It is determined whether the hanging load W is within the rated total load.
In this determination, if the load is other than the rated total load, the lifting operation of the load 22 is stopped, and the operation of the boom 5 on the danger side of the ups and downs (boom lowering operation) is stopped. Maintain sex.

Thus, the present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified invention.

[0017]

As described in detail in the above embodiment, the present invention detects the boom pendant rope ground angle, the boom pendant rope tension, and the boom ground angle, and outputs the detected values, the boom foot and the pendant. Calculating the moment arm length of the pendant rope corresponding to the hanging of the pendant rope based on the distance to the rope base, and the included angle between the connecting line connecting the boom foot and the pendant rope base and the boom center line, and The lifting load of the crane is calculated by calculating the crane moment ratio using the moment arm length as a calculation element. Therefore, the present invention is an invention having a truly remarkable effect, for example, a highly safe and efficient cargo handling operation can be performed based on the hanging load corresponding to the hanging (dip) of the boom pendant rope.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a side view of a large self-propelled crane.

FIG. 2 shows an embodiment of the present invention and is a configuration diagram of a crane load detection device.

FIG. 3 is a flowchart showing a calculation procedure of the load detecting device of the crane according to the embodiment of the present invention.

FIG. 4 shows an embodiment of the present invention and is a diagram for calculating a moment arm length of a boom pendant rope.

FIG. 5 is a side view showing a conventional large self-propelled crane.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crane 7 Boom pendant rope 15 Boom pendant rope tension detector 17 Pendant rope base part 18 Boom pendant rope angle detector 19 Computing unit 21 Boom foot α Boom ground angle β Boom pendant rope ground angle γ Connection line and boom center line L Angle of the connecting line connecting the boom foot and the boom pendant rope base H Moment arm length of the boom pendant rope when hanging down due to its own weight T Tension of the boom pendant rope W Crane hanging load

Claims (1)

[Claims] 1. A pendant rope angle detector for detecting a ground angle of a pendant rope, a pendant rope tension detector for detecting a tension of a pendant rope, a boom angle detector for detecting a boom ground angle, and these detectors Moment arm of the pendant rope corresponding to the hanging of the pendant rope based on the output value of the pendant rope, the distance from the boom foot to the pendant rope base, and the included angle between the connecting line connecting the boom foot and the pendant rope base and the boom center line A load detecting device for a crane, comprising: a calculating device that calculates a hanging load of the crane by calculating a moment ratio of the crane around the boom foot using the moment arm length as a calculation element after calculating the length.