JPH10291779A - Device and method for preventing overturn of crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an operator perform the overturn avoiding operation with enough time by increasing the time latitude from the time when an alarm for informing danger of turnover is output to the time of the actual overturn. SOLUTION: Whether a crane is to be overturned or not is judged by taking the rotational center of a joint part 14 of an outrigger 10 as the overturn fulcrum H. When it is judged that the crane is to be overturned, an alarm signal is output. Since a fixing command signal for fixing the turning movement of the joint part 14 is output when the alarm signal is output or until an alarm signal is to be output, the operation of the joint part 14 of the outrigger 10 can not be performed at the time when the alarm signal is output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tipping prevention device and a tipping prevention method applied to a crane which works while supporting a vehicle body with an outrigger.

[0002]

2. Description of the Related Art When working with a mobile crane in which an outrigger extends outward from a vehicle body and a suspended load is suspended by an upper working machine such as a boom or an auxiliary jib.
Keeping in mind that the operator is allowed to work within the allowable work area determined by the amount of overhang of the outrigger, etc. Is required.

However, in a situation where an overload is applied or the ground is loosened, the crane may fall down against the intention of the operator even if the operator takes great care.

Therefore, in order to prevent such a sudden fall of the crane, it is determined whether or not there is a risk of falling. If it is determined that there is a risk of falling, the operation of the crane is stopped or an alarm is issued. Various devices have been proposed and developed. For example, in the case of an overload on horizontal solid soil, an overload prevention device that detects the current suspended load amount, stops the operation of the crane when the amount reaches an allowable load (rated load), and issues an alarm is known. It has become.

There is also known a posture detecting device which detects the inclination angle of a vehicle body and outputs an alarm when the detected inclination angle exceeds a predetermined limit value.

[0006]

However, even with a safety device that alerts the operator of the danger of overturning by an alarm, depending on the degree of load and the situation of the ground loosening, the overturning has already occurred at the time the alarm was issued. In some cases, the fall may occur rapidly, shortly after the alarm is issued. For this reason, as an operator, even if an attempt is made to perform a fall avoiding operation such as lowering a suspended load in response to the generation of an alarm, there is no time to take such a fall avoiding operation, and the crane falls down without any change. Serious damage.

[0007] Here, there is a technique disclosed in Japanese Utility Model Laid-Open No. 63-161958 as a technique in which the crane is repositioned to provide a time allowance for the crane to fall even slightly. The invention described in this publication is to extend the jack cylinder of the outrigger on the side where the ground has sunk and extend it by the amount of the sunk to maintain the level of the vehicle body.

However, at the time when the crane is about to overturn, the invention described in this publication cannot be re-established again, and the crane is to be overturned.

The present invention has been made in view of such a situation, and in the early stage of the crane falling, it is noted that the falling can be avoided by unloading the suspended load, etc. By expanding the time margin from when the danger warning is output to when the vehicle actually falls, it is possible to allow the operator to perform the fall avoidance operation with sufficient time to avoid the crane falling. The task is to be able to do so.

[0010]

SUMMARY OF THE INVENTION Therefore, according to the main invention of the present invention, an outrigger leg which is attached to a vehicle body so as to project freely, and is rotatably supported on the outrigger leg via a joint. An outrigger float having a grounding surface that is grounded to the ground and supports the vehicle body by an outrigger, wherein the crane has a rotation center of a joint part of the outrigger as a fall fulcrum. When the crane is determined to fall over, an alarm signal output unit that outputs a warning signal to that effect when the crane is determined to fall, and when a fixed instruction signal is given. And an articulation fixing means for disabling the operation of the articulation of the outrigger, when or when the alarm signal is output Until the alarm signal is output from the alarm signal output means, so as to output the fixing instruction signal.

According to this configuration, as shown in FIG. 14B, it is determined whether or not the crane falls with the rotation center of the joint portion 14 of the outrigger 10 as the falling fulcrum H.
When it is determined that the crane falls, an alarm signal to that effect is output. As a result, the operator can now determine that there is a risk that the crane will fall with the rotation center of the joint portion 14 as the fall fulcrum H, and can start a predetermined fall avoidance operation.

On the other hand, when the alarm signal is output or before the alarm signal is output, the fixing instruction signal for fixing the rotation of the joint 14 is output, so that the alarm signal is output. At this time, the operation of the joint 14 of the outrigger 10 is disabled.

As a result, the falling fulcrum is moved to the point H 'of the outer end 15b of the outrigger float 15. That is, the overturning fulcrum moves outward by an amount α corresponding to the width of the outrigger float 15. For this reason, the crane that has been about to fall is returned to a state in which it does not fall, or the operator has enough time to perform the above-mentioned predetermined fall avoidance operation until the crane falls around the new fall fulcrum H ′. It is possible to continue with.

As described above, according to the present invention, there is a danger of falling even if the warning is issued and the vehicle is already falling due to the load applied and the condition of the ground loosening. When the warning is output, the fall fulcrum is moved outward and the time margin until the fall is actually expanded by that amount, so that the operator can perform the fall avoidance operation with a margin. Will be able to do it.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a crane overturn prevention apparatus and method according to the present invention.

FIG. 7 is a diagram showing a side view of the crane vehicle 1 to which the present invention is applied.

The crane vehicle 1 has a vehicle body 2 which is a lower traveling body, an outrigger 10 attached to the vehicle body 2 and whose overhang width can be adjusted, and a revolving body (upper revolving body) which is revolved with the vehicle body 2 as a base. ) 5, a boom 3 supported by the revolving body 5, moving up and down in the up-and-down direction, and having a boom length that can be extended and contracted, and a lifting and lowering hanging from the tip of the boom 3. And a hook 7 provided at the tip of the rope 6 to lock the suspended load 4.

The outrigger 10 is a so-called H-shaped outrigger. As shown in FIG.
Outrigger legs 12 are respectively attached to the front right, front left, rear right, and rear left portions of the vehicle body 2 so as to freely protrude left and right in the left-right direction.
Adjustable from the minimum width Lmin to the maximum width Lmax. As described later, the outrigger tension width sensors 42a for detecting the distance from the vehicle body to the tip of the overhang position are provided on the front right, front left, rear right, and rear left outrigger legs 12 of the vehicle body 2,
42b, 42c, 42d are provided, and the overhang width L (front side, rear side) of the outrigger 10 is measured based on the detection values of these outrigger tension width sensors 42a, 42b, 42c, 42d. I have. In the H-shaped outrigger 10, the height supporting the vehicle body 2 is adjusted by the jack cylinder 13.

Some cranes are provided with a so-called X-shaped outrigger 11, and this X-shaped outrigger 11, as shown in FIG. 9 viewed from the same direction as FIG.
By changing the angle of intersection between the pair of left and right outrigger legs 16, 16, the height at which the vehicle body 2 is supported is adjusted. Similarly to the H-type outrigger 10, the X-type outrigger 11 has the outrigger legs 16 attached to each of the front right, front left, rear right, and rear left portions of the vehicle body 2 so as to freely project in the left-right direction. The overhang width L of the outrigger 11 is adjusted from a minimum width Lmin to a maximum width Lmax.

FIG. 10 is a view showing the tip of an outrigger leg 12 of an H-shaped outrigger 10. As shown in FIG. 10, the tip of a rod 13a of a jack cylinder 13 has a ball joint as an articulation. The outrigger float 15 is connected to the outrigger float 15 via a pivot 14 so that the outrigger float 15 can rotate freely with respect to the rod 13a in the right, left, front and rear directions.

The outrigger float 15 has its ground surface 1
The grounding surface 15a is a distance from the center of rotation H of the ball joint 14 to the outer end 15b of the outrigger float 15 (the distance in the lateral direction of the vehicle body).
has α.

As described above, the outrigger float 15 can be rotated right and left and back and forth through the joints, so that the entire ground contact surface 15a is brought into contact with the ground even in a place having an inclination or unevenness, thereby supporting the vehicle body 2 in a horizontal state. be able to.

FIG. 11 shows the ball joint 14 of FIG.
As shown in more detail in the connection mode between the outrigger float 15 and the outrigger float 15, the ball joint 14 is provided with a load sensor 41 which is a reaction force sensor for detecting a ground reaction force F received on the ground surface 15a of the outrigger float 15. ing.

FIG. 12 is a view showing the distal end portion of the outrigger leg 16 of the X-shaped outrigger 11. As shown in FIG. 12, the distal end of the outrigger leg 16 has a biaxial pin as an articulated portion. 18, is connected to the outrigger float 19 via the link 17, and the outrigger float 19 is
The pin 18 is rotatable with respect to the biaxial pin 18 with left, right, front and rear degrees of freedom.

The link 17 is provided with a reaction force sensor 41, the ground surface 19a of the outrigger float 19 is in contact with the ground, and the distance from the center of rotation H of the pin 18 to the outer end 19b of the outrigger float is a predetermined distance. α is
It is the same as the H-type outrigger 10.

The outriggers 10 and 11 as described above are extended by a predetermined overhang width L and jacked up, so that the vehicle body 2 is lifted and leveled, and the crane 1 is kept level and stable. However, as described above, depending on the degree of load and the looseness of the ground, the operator may suddenly fall over, even if the operator pays considerable attention.

FIG. 13 (a) showing the upper surface of the crane 1 and FIG. 13 (b) showing the side surface of the crane 1
The fall can be described mechanically with reference to FIG. 13 (a). The overturn limit area connecting the four outrigger floats 15 and 19 of the overhanging outriggers 10 and 11 with the ground points (falling fulcrum H) This occurs when the combined center of gravity G of the crane 1 including the suspended load 4 moves outside the area boundary line shown by a broken line.

That is, when the combined center of gravity G of the crane 1 is located inside the above-mentioned overturn limit region, the crane 1 is in a stable state and no overturn occurs. However, when the composite center of gravity G is located on the boundary line (falling line I) of the above area,
When the vehicle reaches the overturn limit state just before the overturn occurs and the combined center of gravity G exceeds the boundary line (overturn line I) of the above-mentioned region, overturning occurs.

However, in the actual fall judging device, it cannot be detected and judged that the combined center of gravity G of the crane 1 is located outside the fall limit region, and only that it is located inside the fall limit region. Since it can be detected and determined, when it comes close to or coincides with the boundary line of the fall limit area by a predetermined distance,
It is determined that the crane 1 falls.

FIG. 13A shows a quadrangular area formed when the outrigger is a four-legged type, but a polygon formed when the outrigger is a three-legged type or a five-legged type. The situation is the same in the case of the region.

Therefore, by returning the combined center of gravity G of the crane 1 to the inside of the overturn limit region by some means, it is theoretically possible to avoid overturn. However, the inertia of the crane 1 is large, and it is practically not technically easy to apply force and energy to the crane 1 to push the crane 1 back inside the overturn limit area due to the inertia.

Therefore, in the present embodiment, the outrigger 1
Joints 0 and 11 (ball joint 14, pin 18,
By fixing the rotating portion of the link 17), the fall fulcrum is moved from the joint to the end 15b (in the case of an H-type outrigger), 19
b (in the case of an X-type outrigger) to avoid falling. That is, even if the combined center of gravity G is outside the fall fulcrum H (the corresponding fall line I) in the initial stage of the fall, the combined center of gravity G is located inside the ends 15b and 19b of the outrigger floats 15 and 19. As long as the fall fulcrum is moved to the end portions 15b and 19b, the time until the fall can be earned, and the fall avoidance operation can be performed during that time.

This will be described with reference to FIGS. 14 (a) and 14 (b). In the case of the prior art in which the joint is not fixed (FIG. 14 (a)), the initial state of the fall from the stable state is indicated by the arrow. Even if the state shifts to the state described above, the falling fulcrum before and after that state remains unchanged as the rotation center H of the ball joint 14 which is the joint of the outrigger 10. Therefore, when the position G of the center of gravity of the crane 1 exceeds the fulcrum H, the crane 1 falls down.

On the other hand, in the case of this embodiment (FIG. 14)
(B)) The operation (rotation) of the joint portion 14 of the outrigger 10 is disabled at the time of transition from the stable state to the initial fall state. As a result, the fulcrum of falling was the ball joint 1
4 is moved from the rotation center H to the point H ′ of the outer end 15 b of the outrigger float 15. That is, these H, H '
The falling fulcrum moves outward by the distance α between the points. For this reason, the center of gravity position G is located inside the new overturning fulcrum H ′, and the crane 1 that has been overturning is returned to a state where it does not overturn, or the crane is overturned around the new overturning fulcrum H ′. By this time, the operator can have a sufficient time to perform a predetermined fall avoidance operation. Although FIG. 14 illustrates the H-type outrigger 10 (see FIG. 8), the same applies to the case of the X-type outrigger 11 (see FIG. 9). FIG. 1 is a block diagram showing a configuration of a fall prevention device performed in the present embodiment. As shown in FIG. 1, the fall prevention device includes a fall detector 40 for detecting a degree of danger of the crane 1 falling. When,
Based on the output of the fall detector 40, as described later, it is determined whether or not the crane 1 falls with the rotation center of the joint of the outriggers 10 and 11 as a fall fulcrum H. As a result, when the crane 1 falls, If the determination is made, a fixing instruction signal for fixing the rotation of the joint portion, a warning signal indicating that there is a possibility of falling, and an output signal of the falling detector 40 are used to output the current danger of the crane 1 falling. A controller 50 that outputs a display signal for displaying the degree, and an outrigger float fixing device 20 that operates to disable the operation of the joints of the outriggers 10 and 11 according to the fixing instruction signal output from the controller 50. An external alarm device 60 that generates an alarm with sound, display, or the like according to an alarm signal output from the controller 50; And a display device 70 for displaying the degree of danger of falling according to the display signal. The external alarm device 60 and the display device 70 are arranged at positions where the operator can recognize them.

In the case of FIG. 1, the fall detector 40 is
1. Reaction force sensors 41a (sensors provided on the outrigger legs at the front right of the vehicle body), 41b (same front left), 41c (same rear right), 41d (same rear left) as shown in FIG.
You are using

As the reaction force sensor 41, any type other than a load cell, such as a hydraulic pressure or a strain gauge, can be used.

As the outrigger fixing device 20, FIG.
Various types can be used as illustrated in FIG.

FIG. 15 exemplifies a fixing device for generating high-pressure combustion gas and for disabling the operation of the joint by bringing the fixing member into contact with the joint of the outrigger by the pressure of the high-pressure combustion gas. .

That is, in the fixing device shown in FIG. 15, when the fixing instruction signal (electric signal) from the controller 50 is transmitted to the explosive, the explosive undergoes an oxidation reaction inside the cylinder 22,
The explosive force generates high-pressure gas. Then, the piston of the cylinder 22 is pushed by the high-pressure gas, and is converted into a linear motion of a rod portion connected to the piston. A wedge 23 is provided at the tip of the rod portion.
3 is driven into the gap between the wall member 21 and the link 17, thereby disabling the operation of the link 17 and fixing the outrigger float 15 to the current inclination angle.

When the fixing device shown in FIG. 15 is used, 1) it is possible to construct a lightweight and compact structure.

2) Time until completion of the fixing operation is short.

3) Signal transmission up to the operation portion may be performed only by the electric signal line.

The following advantages can be obtained.

An embodiment in which the cylinder 22 of the fixing device shown in FIG. 15 is replaced with a hydraulic cylinder is also possible.

In the fixing device shown in FIG. 16, when the fixing instruction signal is given, the hydraulic cylinder 24 operates and the rod 24a is pressed against the member 25 on the upper surface of the outrigger float 19, so that the link 17 cannot operate. And the outrigger float 19 is fixed.

In the fixing device shown in FIG. 17, when a fixing instruction signal is given, the brake caliper 27 (hydraulic brake) operates, the rotation of the brake disk 26 provided on the outer periphery of the link 17 is stopped, and the outrigger float 1
9 is fixed.

In the fixing device shown in FIG. 18, when a fixing instruction signal is given, the hydraulic cylinder 28 is operated, and the locking claw member 30 attached to the tip of the rod is connected to the link 1.
The operation of the link 17 is disabled by being engaged with a ratchet 29 provided on the outer periphery of the link 7.
Outrigger float 19 is fixed. In the fixing device of FIG. 19, the cylinder bottom is supported by the rod 13 a via the member 31, and the hydraulic cylinder 33 whose rod tip is supported by the outrigger float 15 via the member 32 receives the fixing instruction signal. When activated, the outrigger float 15 is fixed.

In the fixing device illustrated in FIGS. 16 to 19,
Since the drive source is hydraulic, 1) the fixing operation can be performed repeatedly after the fixing operation as compared with the case of explosives, without requiring replacement of parts and the like.

2) The hydraulic drive source normally provided on the crane can be used as it is.

The advantage is obtained.

The fixing device shown in FIGS. 15 to 19 is an example, and the fixing device 20 can be constituted by arbitrarily combining the following various driving sources, actuators and various fixing systems.

Drive sources and actuators 1) Electricity a) Pushing and pulling wires and pins by solenoids b) Sticking by magnet magnetic force c) Rotating force of motor 2) Hydraulic pressure and pneumatic a) Linear operation by cylinder (lock pin insertion) Others) b) Rotary operation by hydraulic motor c) Rotary operation by rocking motor 3) Explosive a) Expansion and contraction of cylinder b) Rotation of displacement motor ・ Fixed method 1) Friction method: disk brake, drum brake 2) 3) Pulling method with wire ... Cylinder 4) Pushing method with screw point ... Motor, rack and pinion 5) Claw wheel (ratchet) method 6) Wedge method Hereinafter, refer to the flowchart of FIG. The processing performed by the controller 50 of the fall prevention device in FIG. 1 will be described.

First, each detection value of the reaction force sensors 41a to 41d is input (step 101), and a display signal is generated based on the detected reaction force F of each sensor. Based on the display signal, FIG. As shown, the display screen 71 of the display device 70 displays a display indicating the degree of risk of falling of the crane 1. That is, on this display screen 71, the danger level (reaction force value situation) until the vehicle body 2 falls over in the front, rear, left and right directions.
Is displayed as a bar. By visually recognizing such a display screen 71, the operator can determine whether or not the crane 1 falls over with the rotation center of the joint of the outriggers 10 and 11 as the overhanging fulcrum H (step 103).

On the other hand, based on the detected reaction force F of each sensor, the sum F 'of the reaction force values detected by two adjacent sensors is calculated.
Is sequentially calculated. The reason for calculating the sum of the reaction force values of the two adjacent sensors in this way is that the bias state of the combined center of gravity of the crane 1 can be determined from this value (step 10).
2).

With respect to the sum F 'of the calculated reaction force values,
The center of rotation of the joints of the outriggers 10 and 11 is set to a falling fulcrum H
A first threshold value (for example, set to zero) for determining whether the crane 1 falls or not, and whether the sum F 'of the reaction force values approaches the first threshold value. A second threshold value for determination (greater than the first threshold value)
Are set in advance, and the present reaction force sum F ′ is compared with the first threshold value and the second threshold value (step 104).

As a result, the sum F 'of the current reaction force values is calculated by the second
When the crane 1 is larger than the first threshold, it is determined that the crane 1 is in a normal state in which the crane 1 does not fall. It is determined that the vehicle is approaching the falling risk range, and a forecast signal indicating that the vehicle is approaching the falling risk range is output to the external alarm device 60. As a result, the external alarm device 60 issues a warning sound (step 105).

Further, when the sum F 'of the current reaction force values becomes equal to or less than the first threshold value, the crane 1 sets the rotation center of the joints of the outriggers 10 and 11 as a fall fulcrum H. It is determined that the vehicle has entered the falling risk range of falling, and a fixing instruction signal is output to the outrigger float fixing device 20 and an alarm signal is output to the external alarm device 60. As a result, the outrigger fixing device 20 operates, and the operation of the joint portion 14 of the outriggers 10 and 11 is disabled. In the external alarm device 60, an alarm sound is issued.

Here, the operator can judge that the crane 1 is likely to fall over with the center of rotation of the joint as the overhanging fulcrum H based on the alarm sound or the forecast sound that has already been issued. Can be started. At this point, since the operation of the joint is disabled, as shown in FIG.
The overturning fulcrum is moved from the rotation center H of the joint to the point H ′ of the outer ends 15b, 19b of the outrigger floats 15, 19. That is, the overturning fulcrum moves outward by the distance α between these points H and H ′. For this reason, the center of gravity G of the crane 1 is located inside the new overturning fulcrum H ′, and the crane 1 that has been about to overturn is returned to a state in which it does not overturn, or the new overturning fulcrum H ′ is used as a fulcrum. Until the crane 1 falls, the operator is given time to perform the above-mentioned predetermined fall avoiding operation (step 106).

As described above, according to the processing shown in FIG. 5, the crane 1 may have already fallen over at the time when the alarm was issued, depending on the degree of load and the condition of the ground loosening. Even so, when the warning to notify the danger of falling was output, the falling fulcrum was moved outward and the time margin until actually falling was expanded by that much, so the operator was The fall avoidance operation can be performed with a margin.

In the process of FIG. 5, it is determined that the vehicle falls over when the sum F 'of the reaction force values detected by the two adjacent sensors is equal to or smaller than the threshold value. It may be determined that the vehicle falls over when the sum F ′ of the reaction force values detected by the two sensors is equal to or greater than a predetermined threshold value.

Further, the reaction force values of the adjacent sensors may be individually compared with the threshold value to determine the fall without calculating the sum of the reaction force values.

Further, it may be determined that the vehicle falls over based on the reaction force value of one sensor.

Since the threshold value used for comparison with the current reaction force value changes according to the current crane weight, the suspended load, the fuel weight, etc., the weight is measured at each point in time. It is desirable to sequentially reset the threshold value.

In the process of FIG. 5, the reaction force F obtained by the reaction force sensor is used as it is, but the time change rate dF / dt of the reaction force F is calculated, and the time change rate dF / dt is calculated. Is greater than or equal to a predetermined threshold value.
May be determined to fall.

The threshold value in this case may be set as follows.

1) A time change rate dF / dt which cannot occur in a normal hanging operation is set as a threshold value.

2) Time change rate dF / which cannot occur when there is no man-made work operation such as undulation and expansion and contraction of the main auxiliary jib, hoisting and lowering of the main auxiliary winch, and turning of the upper revolving unit.
dt is set as the threshold.

3) When the operation of the work machine and the turning of the upper revolving structure are performed, the posture and the operation contents of the work machine and the like are fed back, and the threshold value is sequentially reset.

In this case, in order to cope with a sharp time change of the reaction force at the time of the ground-cutting operation, the change of the load applied to the boom 3 at the time of the land-cutting operation is detected and monitored by a predetermined load detector. It can be determined whether or not the time change of the reaction force is due to the ground-cutting operation.

Next, as shown in FIG.
The process performed by the controller 50 of the overturn prevention device in FIG. 2 in which the outrigger tension width sensors 42a to 42d are added to 0 will be described with reference to the flowchart in FIG.

As shown in FIG. 6, first, the detection values of the outrigger tension width sensors 42a to 42d are input (step 201), and the detected tension widths of these four legs are used as shown in FIG.
As shown in (a), the current position of the fall fulcrum H and the position of the fall line I are calculated, and a fall limit area is set (step 202).

Next, the respective detected values of the reaction force sensors 41a to 41d are input (step 203), and the detected reaction force F of each detected sensor and the detected tension of the outrigger tension width sensors 42a to 42d determined above. , The composite gravity center position G of the crane 1 is calculated (step 204).

Therefore, the currently calculated composite gravity center position G
Is compared with the set overturn limit area. Also in this case, similarly to step 104 in FIG. 5, a first threshold value for determining whether or not the center of gravity position G is located on the boundary line I of the overturn limit region, this first threshold value Is set (step 205).

As a result of this comparison, if the position G of the center of gravity does not reach the second threshold value, it is determined that the crane 1 is in a normal state in which it does not fall (stable state in FIG. 13A). If the value falls within the range from the second threshold value to the value less than the first threshold value, it is determined that the vehicle is approaching the danger range of falling. Is output. As a result, the external alarm device 60 issues a warning sound (step 20).
6).

Further, when the position G of the center of gravity reaches the first threshold value, the crane 1
It is determined that the vehicle has fallen into a fall danger range in which the center of rotation of the joint part falls with the fall fulcrum H as a fall fulcrum H (fall limit in FIG. 13A),
A fixing instruction signal is output to the outrigger float fixing device 20, and an alarm signal is output to the external alarm device 60. As a result, the outrigger fixing device 20
Is activated, and the operation of the joint portion 14 of the outriggers 10 and 11 is disabled. In the external alarm device 60, an alarm sound is issued (step 207). The position G of the center of gravity is always displayed on the display screen 71 of the display device 70 (step 208; see the + mark in FIG. 4).

As described above, in the case of the process shown in FIG. 6, as in the process shown in FIG. 5, the crane 1 is already turned on at the time when the alarm is issued, depending on the degree of load and the condition of the ground loosening. Even if you are about to fall, move the fall fulcrum to the outside when the warning to notify you of the danger of falling is output, and allow enough time to actually fall. Since the enlargement is performed, it is possible to allow the operator to perform the overturn avoiding operation with a margin.

In the apparatus shown in FIG. 2, the outrigger tension width sensors 42a to 42d are provided in order to supply a signal indicating the outrigger tension width to the controller 50. May be input via the input device. Further, as shown in FIG. 3, another fall detector 40 may be further added.

FIG. 3 shows how the load applied to the boom 3 is detected.
When the load is equal to or greater than a predetermined threshold value, the overload prevention device 43 that determines that an overload has been applied (there is a risk of falling), the inclination angle of the vehicle body 2 of the crane 1 is detected, The vehicle body tilt angle detector 44 (and a determination device based thereon) that determines that the vehicle has become in an unstable posture (there is a risk of falling over) due to the tilt angle being equal to or greater than a predetermined threshold value, And the like (an operator and a supervisor outside the crane, etc.) are illustrated when the manual switch 45 that is operated when it is determined to fall down is added.

As a result, the controller 50 determines not only that the center of gravity position G of the crane 1 has exceeded the overturn limit region, but also that the controller 50 has overloaded, and that the inclination angle of the crane 1 falls. It is possible to output a fixed instruction signal and an alarm signal (forecast signal) at an accurate timing by comprehensively judging the judgment result that a certain inclination angle has been reached and the judgment result of the operator or the like.

For example, each of the determination results, out of the determination results,
If at least one crane 1 is determined to be in danger of tipping over, and it is determined, a fixed instruction signal and an alarm signal (forecast signal)
May be output. In consideration of the malfunction, all the judgment results and the judgment result indicate that there is a danger of the crane 1 falling down, and only when the fixed instruction signal and the alarm signal (forecast signal) are determined. May be output. In short, a determination result required to output a fixed instruction signal and an alarm signal (forecast signal) and a combination of the determination results can be arbitrarily set according to the work situation of the crane 1. In addition, the fall detector 4
As 0, the following may be used in addition to the above.

1) The magnitude of the axial force measurement value of the undulating cylinder,
Alternatively, it detects the rate of change of the axial force value over time.

2) Detecting a work machine inclination angle, a vehicle body inclination angle, or a rate of time change of these inclination angles.

3) By using an accelerometer attached to a working machine, etc.
Detects acceleration at a specific position.

In the above-described embodiment, if it is determined that the crane 1 falls, the crane 1 is automatically controlled to automatically output a fixing instruction signal. It is also possible to provide a manual switch that is operated to be turned on when it is determined, and to output a fixed instruction signal in response to turning on the manual switch.

Further, in order to prevent the outrigger float from being fixed unexpectedly when the outrigger is installed and the preparation work becomes complicated, a fixing function release switch for forcibly turning off the fixing instruction signal is provided. It may be.

In the embodiment described above, a fixed instruction signal is output simultaneously with the output of the alarm signal.
Although the joints of the outriggers 10 and 11 are fixed, the joints of the outriggers 10 and 11 may be fixed by outputting a fixing instruction signal at least until an alarm signal is output. For example, a fixing instruction signal may be output between the start of the work by the crane 1 and the output of the alarm signal to fix the joints of the outriggers 10 and 11, and a preparatory step before starting the work of the crane (outrigger). Has already output the fixed instruction signal in the
The joints 0 and 11 may be fixed. In short, the joints of the outriggers 10 and 11 only need to be fixed by the time the information indicating that the crane 1 falls over is set to the operator with the center of rotation of the joint as the overhanging fulcrum H.

When the outrigger floats 15 and 19 are fixed after the outriggers are installed, the hanging operation can be performed with high stability.

[Brief description of the drawings]

FIG. 1 is a control block diagram of an embodiment of a crane overturn prevention device according to the present invention.

FIG. 2 is a control block diagram of an embodiment of a crane overturn prevention device according to the present invention.

FIG. 3 is a control block diagram of an embodiment of a crane overturn prevention device according to the present invention.

FIG. 4 is a view showing an example of a display screen of the display device shown in FIG. 2;

FIG. 5 is a flowchart illustrating a procedure of processing executed by a controller of the fall prevention device illustrated in FIG. 1;

FIG. 6 is a flowchart illustrating a procedure of processing executed by a controller of the fall prevention device illustrated in FIG. 1;

FIG. 7 is a diagram illustrating a side surface of the crane applied to the embodiment;

FIG. 8 is a diagram showing an H-type outrigger.

FIG. 9 is a view showing an X-type outrigger.

FIG. 10 is a diagram showing an outer end portion of the H-shaped outrigger shown in FIG. 8;

FIG. 11 is an enlarged view of a main part of FIG. 10;

FIG. 12 is a view showing an outer end portion of the X-type outrigger shown in FIG. 9;

13 (a) is a top view showing the overturn limit area of the crane, and FIG. 13 (b) is a side view showing the side of the crane corresponding to FIG. 13 (a).

FIG. 14 (a) is a diagram showing a state of a crane falling over according to a conventional technique, and FIG. 14 (b) is a diagram showing a state of a crane falling down according to the present embodiment.

FIG. 15 is a diagram illustrating an outrigger fixing device.

FIG. 16 is a diagram illustrating an outrigger fixing device.

FIG. 17 is a diagram illustrating an outrigger fixing device.

FIG. 18 is a diagram illustrating an outrigger fixing device.

FIG. 19 is a diagram illustrating an outrigger fixing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crane 20 Outrigger fixing device 40 Fall detector 50 Controller 60 External alarm device 70 Display device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiromasa Miyano 7-1, Hattobukichi, Matsudo-shi, Chiba Prefecture Kanto Regional Construction Bureau Kanto Technical Office (72) Inventor Kazuo Watanabe 3-5-1 Shiba Park, Minato-ku, Tokyo 8 Japan Construction Mechanization Association (72) Inventor Kazunori Kuromoto 3-20-1 Nakase, Kawasaki-ku, Kawasaki, Kanagawa Prefecture Inside Komatsu Seisakusho Co., Ltd. (72) Inventor Tadashi Morita 3-, Nakase, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture 20-1 Inside Komatsu Ltd. (72) Inventor Kazuaki Ogusa 3-20-1 Nakase, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside Komatsu Ltd.

Claims (11)

[Claims] An outrigger float portion having an outrigger leg that is attached to a vehicle body so as to protrude freely, and an outrigger float portion rotatably supported by the outrigger leg via a joint portion and grounded to the ground. A crane overturn prevention device configured to support the vehicle body by an outrigger, comprising: a fall determination unit configured to determine whether or not the crane falls with a rotation center of a joint of the outrigger as a fall fulcrum; and Alarm signal output means for outputting an alarm signal to the effect that the crane is determined to tip over when the crane is determined to fall, and joint fixing for disabling the operation of the joint of the outrigger when a fixing instruction signal is given. Means when the alarm signal is output or until the alarm signal is output from the alarm signal output means. Fall prevention apparatus for a crane which is adapted to output the fixing instruction signal. 2. The crane overturn prevention device according to claim 1, wherein the fixing instruction signal is given by manual operation. 3. The crane overturn prevention device according to claim 1, further comprising control means for outputting the fixation instruction signal when the crane is judged to be overturned by the overturn determination means. 4. A control means for outputting the fixing instruction signal when the crane is judged to fall over by the overturn judging means, and an operation switch for outputting the fixing instruction signal in response to a manual operation. 2. The crane overturn prevention device according to claim 1, wherein 5. The crane determining unit determines that the crane falls when a detected value of a tilt angle sensor that detects a tilt angle of a vehicle body of the crane exceeds a predetermined threshold value. The crane overturn prevention device according to claim 1. 6. The fall determining means determines that the crane falls when a detection value of a ground reaction force sensor for detecting a ground reaction force value of the outrigger exceeds a predetermined threshold value. A crane overturn prevention device according to claim 1. 7. The overturn judging means, when the crane falls when the measured center of gravity position of the center of gravity measuring means for measuring the center of gravity of the crane approaches or coincides with the overhanging fulcrum of the outrigger by a predetermined distance. The crane overturn prevention device according to claim 1, wherein the determination is made. 8. The crane judging means judges that the crane falls when a detection value of a load detector for detecting a load applied to an upper working machine of the crane exceeds a predetermined threshold value. A crane overturn prevention device according to claim 1. 9. The joint fixing means generates a high-pressure combustion gas when a fixing instruction signal is given, and causes the fixing member to contact the joint of the outrigger by the pressure of the high-pressure combustion gas. 2. The overturn prevention device for a crane according to claim 1, wherein the device is a fixing unit that disables the operation of the joint. 10. An outrigger float portion having an outrigger leg that is attached to a vehicle body so as to protrude freely, and an outrigger float portion rotatably supported by the outrigger leg via a joint and grounded to the ground. A method for preventing a crane from being overturned, which is applied to a crane configured to support the vehicle body by an outrigger, comprising: determining whether the crane overturns with a rotation center of a rotation part of a joint of the outrigger being overturned. A determination step; an alarm signal output step of outputting an alarm signal to that effect when the crane is determined to fall; and a joint for disabling the operation of the outrigger joint when the alarm signal is output. A method for preventing a crane from overturning with a fixed part stroke. 11. An outrigger float portion having an outrigger leg portion attached to a vehicle body so as to protrude freely, and an outrigger float portion rotatably supported by the outrigger leg portion via a joint portion and grounded to the ground. A fall prevention method applied to a crane configured to support the vehicle body by an outrigger, comprising: a fall determination step of determining whether or not the crane falls with a rotation center of a joint of the outrigger as a fall fulcrum. And an alarm signal output step of outputting an alarm signal to that effect when the crane is determined to fall, and a joint that disables the operation of the joint part of the outrigger until the alarm signal is output. A method for preventing a crane from overturning with a fixed part stroke.