JPS60258085A - Display device for state of operation of crane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to an operating state display device for a crane, and more particularly to a device for displaying the state of a crane during work on a two-dimensional screen.

(b) Conventional technology Cranes used at construction sites, etc.
There are various types depending on the purpose of each work.

For example, equipment cranes that are fixed on a foundation, cranes that run on rails attached to steel structures in factories, and even cranes that are movable as a whole such as truck cranes and caterpillar cranes. There are things that can be done. These cranes, especially the last mobile ones, are fraught with various dangers. For example, if the weight of a load suspended from the tip of a crane's boom exceeds the crane's rated load, there is a risk that the crane will fall in either direction or the boom will break. be.

Therefore, in order to prevent such risks, cranes are almost always equipped with display devices to inform the crane operator of the status of the crane. This device is generally referred to as a moment limiter, and this moment limiter can be used to control the suspended load, boom elevation angle, boom length, crane working radius, and even the crane's upper rotation. It detects the turning angle of the body, compares it with the rated value, and gives an indication to the operator.

However, if all such elements are displayed, the display becomes complicated, making it difficult for the operator to make a judgment, and there is a risk that an accident may occur due to misunderstanding.

In addition, the rated load of a suspended load changes depending on the length of the boom, the boom's elevation angle, etc., but some models calculate the rated load by taking these factors into consideration and simplify the display.
In either case, it is an analog display or a digital display, and for example, the first action is to read the number, and the second action is to judge whether it is dangerous or not, so the judgment is immediate. There were none or they were scarce. Furthermore, judgments based on such numbers have often been prone to misperceptions.

In addition, in conventional moment limiters, fluctuations in the rated value when the suspended load swings are not taken into consideration because it is extremely complicated, and the operator has to rely mostly on his or her intuition. Ta.

Furthermore, in addition to the above, consideration must be given to the fact that the upper revolving body of a crane generally has a shape that protrudes rearward, so when turning, it is necessary to pay close attention to the rear of the crane. It is a must. In other words, the crane's upper revolving body has a large overhang, especially at the rear, making it difficult for the operator to see behind while the crane is swinging, and there are blind spots, forcing the operator to operate based on intuition, which can result in contact with surrounding obstacles. It happened often. Therefore, conventionally, when the crane is turning, a person (for example, an observer or a sling person) is placed outside the crane to monitor it.

However, noise levels are generally high at sites where work is carried out using cranes, and even if guidance or warnings are given by voice or whistle, there are cases where the guidance or warnings are not conveyed reliably.

A method of giving signals by hand has also been implemented, but visibility is obstructed by weather or obstacles, resulting in errors or delays in signaling, and this method is also extremely uncertain and dangerous. The method of giving a signal by sound or hand requires an additional person to act as a supervisor, which also poses a problem in that personnel costs increase accordingly.

(c) Purpose The present invention was made in view of the above-mentioned conventional problems, and
The purpose of this is to enable the operator to immediately determine whether the crane is in a stable condition, to be able to clearly recognize at all times the extent to which the crane can be operated, and to To provide an operating state display device for a crane that allows an operator to perform work while monitoring the surrounding state without any human intervention.

(d) Configuration Hereinafter, the configuration of an embodiment of the present invention will be explained based on the drawings.

FIG. 2 shows a side view of a truck crane to which the present invention can be applied.

In the same figure, ■ is a truck that is a crane dolly, and 2
is an upper revolving body which is loaded on a truck 1 and can rotate around a turning center 0, and the base end of a boom 3 which is vertically undulating and whose length is variable is attached to the upper revolving body 2. has been done.

A load 4, which is an object to be lifted by the crane, is suspended from the tip of the boom 3 by a wire rope. The truck 1 has four outriggers 5a, 5b that protrude downward and support the entire truck with the wheels floating.
5c and 5d are provided, and in the state shown in the figure,
These four outriggers 5a to 5d support the truck crane on the foundation ground 6.

FIG. 3 shows a plan view of the truck crane of FIG. 2.

In the figure, reference numeral 7 indicates an operator of the truck crane, and reference numeral 8 indicates an obstacle that exists in the turning area of the upper revolving superstructure 2 and is in danger of coming into contact with when turning, and is generally located at a position that cannot be seen from the position of the operator 7. Each outrigger 5a to 5d
Although not shown in the figure, a load detector is installed in each of them.
Floats 9a and 9b, which are 1° holding members,
It is provided so that the load applied to 9c and 9d can be detected. This load detector is, for example, each outrigger 5a to 5.
It consists of a strain gauge attached to the surface of d or a strain gauge type load transducer inserted in the load transmission system, and each strain gauge is used to form a Wheatstone bridge to electrically measure changes in the resistance value of the strain gauge. By detecting the load applied to each float 9a to 9d, the load applied to each float 9a to 9d is detected. Therefore, the sum of the outputs of these load detectors is the entire weight of the crane including the suspended load 4.

The position of the center of gravity G of the entire crane including truck 1 is the fourth
Based on the figure, it can be concluded as follows. This figure shows the floats 9a to 9d and the center of gravity G in an X-Y coordinate system, with the crane's rotation center 0 as the origin. The spacing between floats 9a-9c and floats 9b-9d is Q, the spacing between floats 9a-9b and floats 9c-9d is Q, and each float 9a + 9b.

The loads applied to 9c and 9d are P+ and P, respectively.
g, Pg, and P4, the position of the center of gravity 8-G (xy y) is G (X+ Y) = G (Q (Pg 4-PI g
) /2Wg, L (P+ 2-Pg 4 )/2W
g) It can be considered as (1). Here Wg is P
+.

The sum of Pg, Pa, P4, P+2 is the sum of Pl and Pg, P
+ a is the sum of Pl and Pa, P24 is the sum of Pg and P4, p
H4 means the sum of Pg and P4, respectively. The crane is supported by these four floats 9a to 9d, but if the position of the center of gravity G (x + y) determined by equation (1) is surrounded by floats 98 to 9d, which are supporting members of the truck, It can be seen that if the crane goes outside the designated area, the crane will start to tip over.

However, the reason why the stability or instability of the crane is discussed inside and outside the area surrounded by each of the floats 9a to 9d is because each of the outriggers 5a to 5d is in a rigid state and is fixed to the truck crane. limited to cases. As shown in FIG. 5, the actual outriggers 5a to 5d have a structure in which one end thereof is fitted into an outrigger box IO provided at the bottom of the track 1. Since the outrigger 5 has a play of δ inside this outrigger box IO, when a load is applied to the outrigger 5 exceeding the δ limit, the outrigger 5
begins to bend in a downward convex state. Therefore, even if the track 1 is installed on a horizontal ground and the outriggers 5a to 5d are evenly extended, one of the outriggers may rise due to the flexure of the outrigger 5. Taking these things into consideration, FIG. 6 shows the stable region and unstable region of the position of the center of gravity G (x*y) in a static state of the truck crane.

In Fig. 6, the line connects the midpoints of each float 98 to 9d, and if the center of gravity G is located outside the area surrounded by this line (■), it will naturally fall over and be dangerous. is obvious. Next, float 9b
, 9d are only in contact with the ground and do not receive any reaction force from the ground, and are in the state shown by the broken line in FIG. 5, the center of gravity G is on the line 2 connecting floats 9a and 90. At this time,
Assuming that the sum of the weights of the outrigger 5b and the float 9b is Wb, and the sum of the weights of the outrigger 5d and the float 9d is Wd, and the center of gravity G gradually approaches the flow)-9b and 9d sides, then X+ = (Wb +Wd) /Wg” Q (2)
As shown in Fig. 5, up to the line A drawn at a distance X1 from the line (1), which is approximately determined as It is a region of metastable state. Similarly, distance X2 from the line ■ connecting floats 9b and 9d. The distance Y1 from line I connecting floats 9a and 9b and the distance Y2 connecting floats 9c and 9d are respectively: X2 = (Wa + Wc) /Wg-fl (3)
Y+ = (We +Wd)/Wg'L (4)
Y 2 = (Wa + Wb)/Wg ” L (5
) is a statically metastable region up to line 11-A drawn at a point approximately determined as ).

(Here, Wa and We are defined in the same way as Wb and Wd.) In addition, this line A is actually connected to the outrigger box 1 as shown in FIG.
0 and the outrigger 5, and the line A is statically unstable.

The line J is a line indicating a boundary when one of the outriggers 5 tries to rise due to elastic deformation as described above. This line J is obtained by connecting substantially midpoints of lines I, respectively. Regarding the stability of the region, it can be said that the area on the float 9 side (outside) of the line J is a quasi-stable area, and the area on the rotation center O side is a stable area. Next, line B is obtained for the same reason as line A, and this line B also has a width corresponding to the backlash caused by the play δ, and there is a statically unstable state on this line B. It becomes.

The line 12- arises from the limit of the elevation angle of the boom 3 of the truck crane, and is an area where the center of gravity G cannot exist structurally. For example, the radius Rk of the line can be set as follows. The maximum heave angle of boom 3 is θm
ax, the shortest boom length is Lmjn, the weight of the boom is W
B, the rated load at this time is Wo, the total weight of the truck crane excluding WB and Wo is W, and the distance from the center of gravity of W from the turning center is r. From the suspension of moments, Rk = ((WB / 2 +WO) ・Lmin-
cosθmax−W−r)/(WB+Wo+W) (6
).

When the area is divided as described above, the area surrounded by each line and the area on the line (a shown in Figure 6)
The stability and instability of a truck crane in a static state in the region (-g) are as shown in the table below.

In the above table, ■ indicates a state where the outrigger 5 is elastically deformed due to the load above the outrigger box 1o, ■ indicates a state between the solid line and the broken line in FIG.
2 indicates a state between the broken line in FIG. 5 and the state where the float 9 is lifted up, and 2 indicates a state where the float 9 is completely lifted up. Further, the symbol O indicates a statically stable state of the truck crane, Δ indicates a statically unstable state, and × indicates an overturning state. Here, since this table only represents stability in a static state, for example, the area is back-to-back with the fall area, which can actually be said to be an unstable area.

As described above, considering the elasticity and structure of each outrigger 5a to 5d, as shown in FIG. It is possible to set a stable region, an irregular region, and an overturning region, each of which means a stable region, an irregular region, and an overturning region, and it is possible to determine the degree of stability of the crane depending on where within these regions the center of gravity G is located.

Next, the turning angle φ (see Fig. 3) of the two-part revolving structure 2 can be determined by, for example, providing a resistance band on either the track 1 or the upper revolving structure 2, and installing a sliding brush in sliding contact with the resistance band on the other side. It is possible to provide a variable resistor and determine the resistance value of the variable resistor.

By using the turning angle φ obtained by such a turning angle detector such as a variable resistance, the axis profile Q (xo +
yo) is the turning center of 0·l by φ.

The position of the contour Q (x, +y) when rotated around the
inφν(xosinφ+y o c'osφ) (6
). Position R of obstacle 8 (xt
y) can be considered to be constant; for example, the upper revolving structure 2 is rotated before the crane works.

The axis profile Q(xoy) at the turning angle φ just before a part of the outline Q(xoy) of the upper rotating body 2 contacts or comes into contact with the obstacle 8
, y) can be expressed as R(x+y). Also,
It is also possible to actually measure and set the distance from each float 9a to 9d.

FIG. 7 shows a display example in which the center of gravity G of the crane, the axis Q of the upper revolving structure 2, and the position R of the obstacle 8, which were set as described above, are displayed superimposed on the screen shown in FIG. 6. It is something that However, in order to simplify the explanation, the widths of areas 1 and 2 and each line shown in FIG. 6 are ignored as being small.

The figure shows that when the center of gravity G is in an area S outside the area surrounded by the line 2, the crane falls over at point 16-. Moreover, when the center of gravity G is in the region T surrounded by the line 3 and the line J, one float is floating, indicating a slightly unstable region. When the center of gravity G is in the area U surrounded by the line J, the most stable state is shown.

When the external axis Q of the revolving upper structure 2 is near the position R of the obstacle 8, there is a risk that the revolving upper structure 2 will come into contact with the obstacle 8. Next, FIG. The means for displaying what is shown on the screen will be explained with reference to FIG.

FIG. 1 is a schematic block diagram showing a circuit configuration of an operating state display device according to the present invention that detects and displays the state of a crane.

In the same figure, 11a, 1 lb, 11c.

11d is the load P1~ loaded on the floats 9a~9d.
It is a load detector that detects P4, and each load detector 11a
The output signals of ~11d are input to the gravity center position calculation means 12. This center of gravity position calculation means 12 receives spacing data L, Q between floats from the initial data setting means 13 and load data P1 to P1 to receive from each load detector 11a to lid.
Based on P4, the center of gravity G is calculated according to equation (1) above.
Find the X and Y coordinates (x, y) of. Reference numeral 14 denotes a turning angle detector, which detects the turning angle φ from, for example, when the upper rotating body 2 is facing forward, and its detection signal is input to the turning position calculation means 15. This turning position calculating means 15 calculates the X and Y coordinates of the axis Q of the upper rotating body 2.

That is, the axis Q of the upper rotating body 2 is formed by seven straight lines as shown in FIG.
5 is the initial data regarding the seven straight lines from the initial data setting means 13, that is, the coordinate Q (xo tyo) when the upper rotating body 2 faces forward and the turning angle from the turning angle detector 14. Q(
xoy). Reference numeral 16 denotes an obstacle position setting means, which outputs a signal indicating the X coordinate and ■ coordinate of the obstacle R when the position of the obstacle is inputted using, for example, a keyboard. 17 is a display signal generation circuit, and center of gravity position calculation means 1
2 output G (X, y), output Q of turning position calculation means 15
(xo y) and the output R of the obstacle position setting means 16
(xoy), the received data are temporarily stored at respective predetermined addresses, the data is subjected to processing necessary for display, and a display signal is sent to a display body 18 such as a CRT. The display unit 18 uses the display signal generation circuit 17 to detect the position of the obstacle R(x, y) and the center of gravity G, which changes from time to time, as shown in FIG. 7, for example.
(xo y) and the contour Q of the upper rotating body 2 (xt y
) controls the display of the position.

FIG. 8 is a circuit block diagram showing the configuration of one embodiment of the gravity center position calculation means of FIG. 1.

In the figure, there are four floats 9a to 9d, :l.

The output value P+ from the load detector 11 installed at.

P2. P9. P4 is added by adder A1 and becomes the total weight Wg. Similarly, adder A2 outputs the output value P
2 and P4 to obtain P'24, and adder A3 outputs P'24.
1 and P3 are added to obtain P+s, and adder A4 outputs the output value P.
Adder A5 adds output values P3 and P4 to output P94, respectively. Adder A1
Wg, which is the output of
is the multiplier of Adder A6 receives the output value P of adder A2.
24 and the output value -pH1 of the adder A3 inverted by the inverting amplifier 11 are input, and the result is outputted to the multiplier C3 as P24-P+3. The float interval data Q manually inputted from the initial data setting means 13 equipped with a keyboard etc. is input as a multiplier to the multiplier C3, and Q. Output to C2. Since 1/Wg 0.5 is input as a multiplier to this multiplier C2, as a result of the multiplication, the X coordinate defined by equation (1) is output to the A/D converter AD. value. Similarly, the output value PI2 of the adder A4 and the output value -P34 of the adder A5 inverted by the inverting amplifier 2 are input to the adder A7, and the result P
I2-PB4 is calculated and the calculation result is output to multiplier C4. The float interval data L is inputted to the multiplier C4 from the initial data setting means 13, and L・(PI
2-P34) to the multiplier C5. This multiplier C5 receives the output from the multiplier C1, 1/Wg・0.
．． 5 is added as a multiplier, resulting in (1)
The Y coordinate defined by the formula is output to the A/D converter AD and becomes a digital value.

As described above, the center of gravity position G (xo y) is calculated and transferred to the display signal generation circuit 17 as a digital signal. In the embodiment shown in FIG. 8, the calculation process is performed by an analog circuit, but each load output value P1 to P
4i (A/D conversion may be performed first, and a microprocessor may perform digital arithmetic processing.

Regarding the turning position calculation means 15, the center of gravity position calculation means 1
Use adders and multipliers in the same way as in 2, and further sjn
, cos can be combined to calculate the turning position Q(X, y).

Next, the processing steps in the display signal generation circuit 17 will be described.

FIG. 9 shows a schematic block diagram of the display signal generation circuit 17.

In the figure, each data G (x + y'), Q (x +
y), R(x+y) are once stored in the data buffer 19 in the display signal generation circuit 17, and then stored at a predetermined address in the display data storage circuit 2o constituted by a video RAM such as a magnetic disk. . Next, each of the stored data is read out by a display data readout circuit 21, processed by a graphic signal generation circuit 22 into a shape according to its display form, and then processed by a display peripheral circuit 23.
output along with a timing signal for display. Here, the graphic signal generation circuit 22 is, for example, a vector generator, and is used to generate figures such as straight lines and circles. The display peripheral circuit 23 includes the display data readout circuit 2
The center of gravity position G is displayed on the display body 18 in response to the timing signal from 1.
, - is used to control the display of the outline Q of the rotating body 2 and the obstacle position R. For example, if the display 18 is a CRT, the X deflection of the deflection plate, the It performs brightness modulation, etc. Further, the display body 18 is
■71-If the liquid crystal display is composed of nematic liquid crystal cells configured in a lix shape, each driver 1 of the liquid crystal display
This is to control the brightness and darkness of -.

Figures 10 (a), (b), and (c) display the schematic diagram shown in Figure 7 on a two-dimensional screen * ya # &
L/T (7) #J+ *yF< tri
(Dm a tx Muku 5 Pass 1° perspective view, front view, and side view.

In the figure, 24 is, for example, an X-Y matrix 23-x liquid crystal display, which is made of a transparent plate on which the lines I, J and floats 9a to 9d shown in FIG. 7 are displayed in advance. Area display board 2 as stability display means
5 are stacked on top of each other.

On the liquid crystal display 24, the center of gravity G, a schematic contour Q of the upper revolving structure 2, and the position (contour) R of the obstacle 8 are displayed.

As described above, in the liquid crystal display 10 placed in front of the operator 7 in the upper revolving body 2 of the crane, the center of gravity G and the position Q of the upper revolving body 2 are displayed in each region S, as shown in FIG. By looking at the positional relationship between T, U and the position R of the obstacle 8, it is possible to determine whether the crane is in a stable state or whether the area around the crane is safe for work. You can judge at a glance whether or not it is. Furthermore, it is possible to know in advance which direction is the most dangerous, depending on the position of the center of gravity G. In this way, the operator alone can safely operate the crane while grasping the surrounding situation. And 2
4- With the conventional moment limiter display method, when a suspended load swings, it is not possible to accurately grasp the condition. However, according to the second embodiment, the center of gravity of the entire truck crane can be adjusted in each area. Since the movement of the suspended load can be visually confirmed, the degree of danger due to swinging of the suspended load can be clearly and easily grasped.

It should be noted that the present invention is not limited to the embodiments described in - above, and various modifications can be made without departing from the gist of the present invention.

For example, in the above embodiment, the center of gravity G is detected by detecting the loads on the floats 98 to 9d, and the turning angle φ is detected by variable resistance. The center of gravity G may be determined based on the elevation angle of the boom 3, the length of the boom 3, etc., and the center of gravity G may be determined based on the elevation angle of the boom 3, the length of the boom 3, etc. Install a coupler etc.
The turning angle φ may be determined by counting the number of pulses generated from them. Furthermore, instead of using the liquid crystal display board 24, a CRT display can be used as the two-dimensional screen. Further, when displaying as shown in FIG. 7, if each area S, T, and U is displayed in a color corresponding to the degree of danger, the judgment becomes even easier. For example, in FIG. 7, when the center of gravity G is within the area U, the center of gravity G is illuminated in white to clearly indicate this position.

In this case, since the crane is stable, for example, the display 18
What is necessary is to light up a green light emitting element such as an LED provided near the . Also, if the crane enters the T area, the crane is unstable, so the yellow light emitting element will be lit, and if the crane enters the S area, there is a risk of it falling over, so the red light emitting element will be lit. good. Furthermore, it is also possible to use a color display without using the LED, and to color each of the S, T, and U areas in red, yellow, green, or the like.

Further, it is also possible to display, for example, an approach warning area around the position R of the obstacle 8 to facilitate safety confirmation.

Furthermore, although the two-dimensional screen display has been described using X-Y coordinates, it can also be expressed using polar coordinates. For example, considering polar coordinates with the turning center O as the origin, the position R of the obstacle 8 can be expressed by the distance from the turning center O and the turning angle φ. Also,
The axis Q of the upper revolving body 2 is expressed by the coordinate Q(x
.

y) is not calculated and plotted on the display 18, but a panel-like object shaped like an upper rotating body and rotating around the rotation center 0 is mounted on a two-dimensional screen, and the image is displayed according to the rotation angle φ. If it is configured to rotate, it will be simpler.

In addition, in the above-mentioned embodiment, each area was set as shown in FIG. 7 based on the theoretical results derived from the structure of the truck crane, and the structure was configured to clearly demonstrate safety.
In reality, Article 55 of the Crane Safety Regulations of the Ministry of Labor stipulates that ``stability tests must be carried out by lifting a load equivalent to 1.27 times the rated load,'' and this rule '1. Even if the region is considered to be stable in the above embodiment, it may be determined to be unstable.

27- Therefore, for example, as shown in Figure 11, draw a circle M centered on the turning center O so that it is approximately tangent to the nearest line ■, and calculate the movement of the center of gravity when a load of 1.27 times the rated load is lifted. In addition, by drawing a circle m with a radius of 1/1.27 of the radius of circle M and using it as the movement range of the center of gravity when lifting the rated load, the display will be made in accordance with the above safety regulations. It can also be done.

(e) Effects As detailed above, according to the first invention, it is possible to always visually check whether the center of gravity of the entire crane is in the stable region or unstable region using the two-dimensional screen, so that the condition of the crane is stabilized. It is possible to provide a crane operating state display device that can instantly determine whether or not the crane is operating.

Further, according to the second invention, since the center of gravity position of the entire crane and the safe working area of the crane can be viewed simultaneously on the two-dimensional screen, it is possible to immediately check whether the condition of the crane is stable or safe. Since the operator can perform the work while monitoring the surrounding conditions of the crane, there is no longer a need for a supervisor, which was required with conventional systems, and the entire personnel cost can be reduced. It is possible to provide a crane operating status display device that can save money.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing a circuit configuration of an embodiment of the present invention, FIGS. 2 and 3 are a side view and a plan view of a truck crane to which the present invention can be applied, and FIG. 4 is a schematic block diagram of the same truck crane. A planar layout diagram in the X-■ coordinate system of four floats installed at the tip of the outrigger of the crane, Figure 5 is a partial cross-sectional view showing the configuration of the outrigger part of the truck crane, and Figure 6 is a diagram of the truck crane. 7 is a diagram showing an example of a screen display mode of the operating state of the crane according to the present invention, and FIG. 8 is a diagram showing the configuration of the center of gravity position calculation means in FIG. 1. FIG. 9 is a circuit block diagram showing more specifically the configuration of the display signal generation circuit shown in FIG. 1, and FIG.
Figures (a), (b), and (c) are perspective views, front views, and side views showing the structure of the display body shown in the first figure in more detail, and Figure 11 is an operating state of the crane according to the present invention. FIG. 6 is a diagram showing another example of a screen display mode. ■... Truck, 2... Upper revolving structure, 3... Boom, 4... Hanging load, 5a
~5d... Outrigger, 7... Operator, 8... Obstacle,
9a-9d...Float, 10...Outrigger box, 11a-lld
... Load detector, 12 ... Center of gravity position calculation means, 13 ... Initial data setting means, 14 ...
・Turning angle detector. 15... Turning position calculation means, 16... Obstacle position setting means, 17...
・Display signal generation circuit, 18...display body, 24...liquid crystal display board, 25...area display board, Q...contour of upper revolving body . R: Outline of obstacle, G: Center of gravity position, O: Crane rotation center, S, T, U: Area, I, J ······line. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) In a crane operating state display device that detects and displays the state of the crane during operation using a plurality of detectors, the center of gravity calculates the position of the center of gravity of the entire crane by using the detected values from the detectors. position calculation means; and display signal generation means for receiving data output from the center of gravity position calculation means, temporarily storing the data at predetermined addresses, performing necessary processing on the data, and sending out a center of gravity position display signal. , a display body that receives the center of gravity position display signal from the display signal generating means and displays the center of gravity position on the screen, and a display body that displays the center of gravity position on the screen, and a stable state and an unstable state of the crane in correspondence with the range in which the center of gravity position moves on the screen. and a crane stability display means for displaying a stable area, an unstable area, and an overturning area, respectively indicating an overturning state, on the display body or another display body laminated on the display body. Crane operating status display device. (2) In a crane operating state display device that detects and displays the state of the crane during operation using a plurality of detectors, the center of gravity calculates the position of the center of gravity of the entire crane based on the detection signals from the detectors. a position calculation means, and a swing position calculation means for calculating a contour position of the upper revolving structure of the crane when viewed from vertically above based on a rotation angle of the upper revolving structure of the crane detected by one of the detectors;
Obstacle position setting means for setting the turning area in which the obstacle exists when an obstacle exists in the turning area of the upper revolving structure; Display signal generating means receives the data output and temporarily stores the data at a predetermined address, performs necessary processing on the data and sends out a display signal; and receives the display signal from the display signal generating means and the center of gravity. A display device that displays the position, the contour position, and the obstacle existence area on a screen, and a stable state, an unstable state, and an overturning state of the crane in correspondence with the range in which the center of gravity position moves on the screen, respectively. Crane stability display means for displaying the meaning of stable area, unstable area and overturning area on the display body or a display body laminated on the display body. Device.